 Distance sensor and control method of a distance sensor.
专利摘要:
The present invention relates to a distance sensor configured to inject an equal amount of current into storage nodes, each coupled to charge collection regions in which the charges of a photosensitive region are distributed by driving the first and second transfer electrodes and a distance to an object obtained based on difference information about charge amounts of the respective storage nodes. The saturation of each storage node caused by stray light is avoided by injecting the same amount of current into each storage node, and the difference information about the amounts of charge of the respective storage nodes not easily affected by the current injection becomes by driving the first and second transfer electrodes according to the plurality of instructions each representing the electrode drive pattern are obtained. Furthermore, the invention relates to a driving method for the inventive distance sensor. 公开号:CH713891B1 申请号:CH01289/18 申请日:2017-04-19 公开日:2019-08-30 发明作者:Akihiro Shimada；Mitsuhito Mase；Jun HIRAMITSU；Takashi Suzuki 申请人:Hamamatsu Photonics Kk； IPC主号:
专利说明:
description Technical Field The present invention relates to a distance sensor and a driving method of a distance sensor. BACKGROUND ART A time-of-flight (TOF) method for measuring a distance to an object based on a time difference between a time of emitting light from a light source and a time when reflected light was received by the object is known. For example, the following patent document 1 describes a distance sensor that is based on a TOF method. The distance sensor disclosed in Patent Document 1 has a charge distribution type configuration in which charges generated during a first period after irradiation with pulsed light and charges generated during a second period after the first period are stored in storage nodes which are each coupled to different charge collection areas. The distance to the object is then calculated from a ratio of the amounts of charge stored in these storage nodes. In addition, the non-patent document 1 describes a method for measuring a distance to an object based on a phase difference between irradiation light and its reflected light by emitting triangular wave light. References Patent Literature Patent Document 1: JP 2011-133 464 (A) Non-Patent Literature Non-Patent Document 1: David Stoppa et al., Introduction to 3D Time-of-Flight Image Sensors, European SolidState Circuits Conference (ESSCIRC), European Solid-State Device Conference (ESSDERC), 2015 Summary of the invention TECHNICAL PROBLEM As a result of studying the above prior art, the inventors found the following problems. This generally means that not only charges due to the reflected light, but also charges due to stray light are stored in the storage node in the distance sensor. In the distance sensor described in Patent Document 1, a charge amount corresponding to the stray light is subtracted from the charge amount obtained in each of the storage nodes when the distance is calculated. Therefore, both the charges caused by the reflected light and the charges caused by the stray light are stored in each of the storage nodes, so that there is a problem that the storage node is slightly saturated. Incidentally, the pulsed light is output in accordance with the method described in Patent Document 1, and thus there is an advantage that an intensity of the irradiation light can be increased with respect to an intensity of the interference light (that is, a signal-to-noise ratio). In addition, the object is irradiated with the triangular wave light by the method described in non-patent document 1, so that it is necessary to constantly set each transfer electrode to an on-potential (potential that enables charge transfer) during one cycle to all to absorb charges generated during a cycle. In this case, a large amount of charge is removed by stray light so that each storage node is slightly saturated. In addition, a light emission state of a light source is continuous compared to the case where the pulsed light is output, and thus there is a problem that an intensity of the irradiation light is suppressed as low and the intensity of the irradiation light with respect to an intensity of the stray light (i.e. a signal-to-noise ratio) is low. It is conceivable to feed current into each storage node in order to balance charges in order to avoid saturation of a storage node. In such a system, it is necessary to perform the current injection in a state where an intensity of the stray light is unknown, and therefore it is desirable to supply an equal amount of current to each storage node and to maintain a distance to an object based on one Difference in the amount of charge stored in each storage node. The difference in the amount of charge is not affected by the current fed in. However, it is difficult to use the distance sensors described in Patent Literature 1 and Non-Patent Literature 1 in such a method. [0009] The present invention has been made to solve the problems described above, and an object is to provide a distance sensor and a driving method for a distance sensor having a structure that it2 CH 713 891 B1 possible to feed an equal amount of electricity into electrically coupled storage nodes in order to charge collecting areas in which the charges of a light-sensitive area are distributed by driving a plurality of transmission electrodes and maintaining a distance to an object based on difference information about charges of the respective storage nodes , Solution to Problem A distance sensor according to the present invention is a distance sensor configured to irradiate an object with light and measure a distance to the object by detecting reflected light from the object, and as an aspect thereof, a light irradiation unit , comprises a semiconductor substrate, a first transfer electrode, a second transfer electrode and a drive unit. The light irradiation unit repeatedly irradiates the object with pulsed light. The semiconductor substrate has a photosensitive region and first and second charge collection regions. The photosensitive area is an area that generates charges corresponding to an amount of light of the reflected light. Each of the first and second charge accumulation areas is an area which is arranged in a state of separation from the photosensitive area by a predetermined distance and collects the charges from the photosensitive area. The first transfer electrode is an electrode which is arranged on a region between the light-sensitive region and the first charge collection region and can be set to an on potential or an off potential. Here, the on potential is a potential that enables the charge transfer from the photosensitive area to the first charge accumulation area, and the off potential is a potential that stops this charge transfer. The second transfer electrode is disposed on an area between the photosensitive area and the second charge collection area and is a potential that enables charge transfer from the photosensitive area to the second charge collection area, and the off potential is a potential to stop this charge transfer. The drive unit sequentially executes a plurality of commands, each of which forms an electrode drive pattern for driving the first and second transfer electrodes and is defined by the uniform times t 0 , L, ... and t 9 , and drives the first and second transfer electrodes , In the configuration described above, the light irradiation unit emits light for times L to t 3 in each of the plurality of commands. In addition, in a first command among the plurality of commands, the control unit sets the first transmission electrode to the on potential between times and t 2 and between times t 4 and t 6 and sets the second transmission electrode to the on potential between times t 2 and t 4 and between times t 6 and t 8 . Furthermore, the control unit sets the first transmission electrode to the on potential between times L and t 3 and between times t 5 and t 7 in a second command different from the first command and sets the second transmission electrode to the on potential between Times and t 5 and between times t 7 and t 9 . Advantageous Effects of Invention The distance sensor according to the present invention is the distance sensor configured to irradiate the object with the pulsed light and which has the structure to feed the same amount of electricity to the storage nodes, each electrically are coupled to the charge accumulation areas in which the charges of the photosensitive area are distributed by driving the plurality of transfer electrodes and obtaining the distance to the object based on the difference information on the charge amounts of the respective storage nodes. According to the distance sensor and the control method of the distance sensor, saturation of each storage node caused by stray light is avoided by feeding the same amount of electricity into each storage node, and the difference information about the amount of charge of the respective storage node, which is not easily influenced by the current injection, is achieved by Driving the first and second transfer electrodes according to the plurality of commands, each representing the electrode driving pattern. Description of the Drawings Fig. 1 Fig Fig Fig Fig 5A is a plan view illustrating a configuration of a distance sensor according to an embodiment of the present invention. Fig. 4 is a plan view of a light receiving unit of each pixel of the distance sensor shown in Fig. 1. FIG. 4 is a cross-sectional view taken along line III-III of FIG. 2. FIG. 2 is a cross-sectional view taken along line IV-IV of FIG. 2. Fig. 5B and 5C are diagrams showing a time change in the intensity of the reflected light incident on a particular pixel, and Figs. 5B and 5C are diagrams showing a time change in a voltage applied to each of two transmission electrodes. CH 713 891 B1 FIG. 6 is a view showing an image area driving system using a Sensor drive circuit illustrated. FIG. 7A is a timing chart illustrating the operations of transfer electrodes in a store instruction of a first instruction, and FIG. 7B is a timing diagram illustrating operations of the transfer electrodes in a store instruction of a second instruction. Fig. 8 is a view showing timing charts of the first command and the second command for a single drive clock in an overlapping manner. Fig. 9 is a view showing a diagram of the received light pulse waveforms of the reflected Light further illustrated in the timing diagram shown in FIG. 8. Fig. 10 is a view showing a diagram of the received light pulse waveforms of the reflected Light further illustrated in the timing diagram shown in FIG. 8. Fig. 11A is a diagram illustrating a relationship between an output value of each pixel and a time from the irradiation of the light to the incidence of the reflected light, Fig. 11B is a diagram showing the signs of the output values in the first command and the second Command illustrates, and FIG. 11C is a view illustrating a method of calculating a total charge amount. 12A to 12C are diagrams illustrating a method for calculating a distance of output values in the first command and the second command. 13 is a circuit diagram showing a detailed configuration of a current injection circuit. 14A and 14B 15A to 15C are views illustrating a timing chart of a driving method according to a first change. are views for describing a distance calculation method according to the first modification. 16 is a plan view illustrating a light receiving unit according to a second modification. FIG. 17 is a cross-sectional view taken along line XVII-XVII of FIG. 16. 18 is a view showing a driving system of a sensor driving circuit according to the second Represents modification. Fig. 19 is a timing diagram illustrating driving a transfer electrode in a store command. Description of the Embodiments [Description of the Embodiments of the Invention of the Present Application] First, those that correspond to the embodiments of the invention of the present application are listed and described individually. (1) A distance sensor according to the present embodiment is a distance sensor configured to irradiate an object with light and to measure a distance to the object by detecting reflected light from the object, and as an aspect thereof, a light irradiation unit , comprises a semiconductor substrate, a first transfer electrode, a second transfer electrode and a drive unit. The light irradiation unit repeatedly irradiates the object with pulsed light. The semiconductor substrate has a photosensitive region and first and second charge collection regions. The photosensitive area is an area that generates charges corresponding to an amount of light of the reflected light. Each of the first and second charge accumulation areas is an area which is arranged in a state of separation from the photosensitive area by a predetermined distance and collects the charges from the photosensitive area. The first transfer electrode is an electrode which is arranged on a region between the light-sensitive region and the first charge collection region and can be set to an on potential or an off potential. Here, the on potential is a potential that enables charge transfer from the photosensitive area to the first charge accumulation area, and the off potential is a potential that stops this charge transfer. The second transfer electrode is arranged on a region between the photosensitive region and the second charge accumulation region, the on potential is a potential that prevents the charge transfer from. photosensitive area to the second charge collection area, and the off potential is a potential to stop this charge transfer. The drive unit sequentially executes a plurality of commands, each of which has an electrode drive pattern for driving the first and second transmitters CH 713 891 B1 forms supply electrodes and is defined by the uniform times t 0 , L, ... and t 9 , and controls the first and second transmission electrodes. In the configuration described above, the light irradiation unit emits light for times ti to t 3 in each of the plurality of commands. In addition, in a first command among the plurality of commands, the drive unit sets the first transmission electrode to the on potential between times tb and t 2 and between times t 4 and t 6 , while the second transmission electrode to the on potential between times t 2 and t 4 and between times t 6 and t 8 . Furthermore, in a second command, which differs from the first command, the drive unit sets the first transmission electrode to the on potential between times L and t 3 and between times t 5 and t 7 , while it switches the second transmission electrode to on -Potential between times t 3 and t 5 and between times t 7 and t 9 sets. (2) As an aspect of the present embodiment, the driving unit of the distance sensor can sequentially execute a plurality of commands, each of which forms an electrode driving pattern for driving the first and second transmission electrodes and by the uniform times tb, L, ... and t 8 is defined for driving the first and second transmission electrodes. In this case, the light irradiation unit irradiates the plurality of commands with light for times ti to t 3 . In addition, in a first command among the plurality of commands, the drive unit sets the first transmission electrode to the on potential between times tb and L and between times t 4 and t 5 , while it sets the second transmission electrode to the on potential between times t 2 and t 3 and between times t 6 and t 7 . Furthermore, in a second command, which differs from the first command, the control unit sets the first transmission electrode to the on potential between times L and t 2 and between times t 5 and t 6 , while it switches the second transmission electrode to on -Potential between times t 3 and t 4 and between times t 7 and t 8 sets. (3) As an embodiment of the present embodiment, the distance sensor may include a light irradiation unit, a semiconductor substrate, first to fourth transfer electrodes and a drive unit. The light irradiation unit repeatedly irradiates the object with pulsed light. The semiconductor substrate has a photosensitive region and first to fourth charge collection regions. Here, the light-sensitive area generates charges that correspond to an amount of light from the reflected light. Each of the first to fourth charge collection regions is arranged in a state of being separated from the photosensitive region by a predetermined distance, and collects the charges from the photosensitive region. The first transfer electrode is arranged on a region between the photosensitive region and the first charge collection region, the second transfer electrode is arranged on a region between the photosensitive region and the second charge collection region, the third transfer electrode is arranged on an region between the photosensitive region and the third charge collection region and the fourth transfer electrode is disposed on an area between the photosensitive area and the fourth charge collecting area. Each of the first to fourth transfer electrodes can be set to an on potential that enables charge transfer from the photosensitive region into the corresponding charge accumulation region, or to an off potential that stops this charge transfer. The drive unit sequentially executes a plurality of commands, each of which forms an electrode drive pattern for driving the first through fourth transfer electrodes and is defined by the uniform times fc, L, ... and t 8 to drive the first through fourth transfer electrodes. In the configuration described above, the light irradiation unit emits light for times ti to t 3 in each of the plurality of commands. In each of the plurality of commands, the control unit sets the first transmission electrode to the on potential between times t 0 and t-ι and between times t 4 and t 5 , the second transmission electrode to the on potential between times L and t 2 and between times t 5 and t 6 , the third transfer electrode sets to the on potential between times t 2 and t 3 and between times t 6 and t 7 and sets the fourth transfer electrode to the on potential between times t 3 and t 4 and between times t 7 and t 8 . (4) In a driving method of a distance sensor according to the present embodiment, a distance sensor that is configured to irradiate an object with light and to measure a distance to an object by detecting reflected light from the object is driven. The distance sensor to be controlled comprises a light irradiation unit, a semiconductor substrate, a first transmission electrode and a second transmission electrode. The light irradiation unit repeatedly irradiates the object with pulsed light. The semiconductor substrate has a photosensitive region and first and second charge collection regions. The photosensitive area is an area that generates charges corresponding to an amount of light of the reflected light. Each of the first and second charge accumulation areas is an area which is arranged in a state of separation from the photosensitive area by a predetermined distance and collects the charges from the photosensitive area. The first transfer electrode is an electrode which is arranged on a region between the light-sensitive region and the first charge collection region and can be set to an on potential or an off potential. Here, the on potential is a potential that enables the charge transfer from the photosensitive area to the first charge accumulation area, and the off potential is a potential that stops this charge transfer. The second transfer electrode is arranged on a region between the photosensitive region and the second charge accumulation region, the on potential is a potential that enables charge transfer from the region to the second charge accumulation region, and the off potential is a potential to stop this charge transfer. In one aspect of the drive method, a plurality of commands, each of which forms an electrode drive pattern for driving the first and second transfer electrodes and is defined by uniform times to, ti, ... and t 9 , are shown in FIG. 5 CH 713 891 B1 executed each other. In particular, light is emitted by the light irradiation unit for times b to t 3 in each of the plurality of commands in the control method. In addition, in a first command from the plurality of commands, the first transfer electrode is set to the on potential between times tb and t 2 and between times t 4 and t 6 , and the second transfer electrode is set to the on potential between in the control process times t 2 and t 4 and between times t 6 and t 8 . Furthermore, in a second command, which differs from the first command, the first transmission electrode is at the on potential between times b and t 3 and between times t 5 and t 7 and the second transmission electrode is at the on potential between times b and t 5 and between times t 7 and t 9 set in the control process. (5) As an aspect of the present embodiment, in the driving method, the distance sensor having the above structure can be set as an object to be driven and a plurality of commands, each of which forms an electrode driving pattern for driving the first and second transmission electrodes and by uniform Times t 0 , b, ... and t 8 are defined can be carried out one after the other. In this case, in each of the plurality of commands, light is emitted from the light irradiation unit for the times b to t 3 of each command in the drive method. In addition, in a first command from the plurality of commands, the first transmission electrode is switched to the on potential between the times t 0 and b and between times t 4 and t 5 are set and the second transfer electrode is set to the on potential between times t 2 and t 3 and between times t 6 and t 7 in the actuation process. Furthermore, in a second command, which differs from the first command, the first transmission electrode is at the on potential between times b and t 2 and between times t 5 and t 6 and the second transmission electrode is at the on potential between times t 3 and t 4 and between times t 7 and t 8 set in the control process. (6) As an aspect of the present embodiment, the distance sensor may include, as the object to be driven in the driving method, a light irradiation unit, a semiconductor substrate and a first to fourth transfer electrodes. The light irradiation unit repeatedly irradiates the object with pulsed light. The semiconductor substrate has a photosensitive region and a first to fourth charge collection region. Here, the light-sensitive area generates charges that correspond to a light quantity of the reflected light. Each of the first to fourth charge collecting areas is arranged in a state of separation from the photosensitive area by a predetermined distance, and collects the charges from the photosensitive area. The first transfer electrode is arranged on a region between the photosensitive region and the first charge collection region, the second transfer electrode is arranged on a region between the photosensitive region and the second charge collection region, the third transfer electrode is arranged on an region between the photosensitive region and the third charge collection region and the fourth transfer electrode is disposed on an area between the photosensitive area and the fourth charge collecting area. Each of the first to fourth transfer electrodes can be set to an on potential that enables charge transfer from the photosensitive region into the corresponding charge accumulation region, or to an off potential that stops this charge transfer. In the driving method, wherein the distance sensor having the above structure is set as the object to be driven, a plurality of commands, each of which forms an electrode driving pattern for driving the first to fourth transmission electrodes and is defined by uniform times tb, L, ... and t 8 is executed sequentially. In particular, in the control process, light is emitted by the light irradiation unit for times L to t 3 , the first transmission electrode is set to the on potential between times tb and t-ι and between times t 4 and t 5 , the second transmission electrode is between the times L and t 2 and between the times t 5 and t 6 set to the on potential, the third transmission electrode set to the on potential between the times t 2 and t 3 and between the times t 6 and t 7 and the fourth transfer electrode set to the on potential between times t 3 and t 4 and between times t 7 and t 8 in each of the plurality of commands. (7) According to the distance sensor and the driving method of each of the various aspects described above, it is possible to obtain the distance based on a difference in the amount of charges stored in each storage node as described in the embodiments to be described later. It is therefore possible to avoid the saturation of each individual storage node by injecting an equal amount of current into each storage node. (8) As an aspect of each distance sensor and the driving method thereof according to the present embodiments, the semiconductor substrate may further include a fifth charge collecting area arranged in a state of being separated and configured from a photosensitive area by a predetermined distance to collect charges from the photosensitive area, and the distance sensor may further include a fifth transfer electrode disposed on an area between the photosensitive area and the fifth charge collection area according to this configuration. In this case, the control unit in the distance sensor sets the fifth transmission electrode to an on potential, with the exception of a period in which the other transmission electrodes are first set to the on potential and then finally to the off potential. In the meantime, the fifth transmission electrode is set to the on potential in the driving method, with the exception of the time in which the other transmission electrodes are first set to the on potential and then finally to the off potential. CH 713 891 B1 (9) According to the distance sensor and the driving method of each of the various aspects described above, it is possible to discharge charges generated by stray light with the fifth transfer electrode, except for a period in which the first and second transfer electrodes ( or the first to fourth transmission electrodes) is driven. This makes it possible to further suppress the saturation caused by the stray light and to reduce the shot noise caused by the stray light and thus to further improve a resistance to the stray light and the distance measurement accuracy. As described above, any aspect listed in [Description of the Embodiment of the Invention of the Present Application] can be applied to any of the remaining aspects or to all combinations of these remaining aspects. [Details of the embodiment of the invention of the present application] Hereinafter, a specific structure of the distance sensor and the driving method of the distance sensor according to the present embodiments will be described in detail with reference to the accompanying drawings. Incidentally, the invention is not limited to these various examples, but is illustrated by the claims, and every change in the equivalent sense and scope of the claims is to be incorporated therein. In addition, the same elements are identified by the same reference numerals in the description of the drawings, and redundant descriptions are omitted. 1 is a plan view illustrating a configuration of a distance sensor 1A according to an embodiment of the present invention. The distance sensor 1A measures a distance to an object by illuminating the object with light and detecting reflected light from the object. As shown in Fig. 1, the distance sensor 1A includes an imaging area 5 formed on a semiconductor substrate 3, a sensor drive circuit 7 (drive unit) and a processing circuit 8. The sensor driving circuit 7 controls the imaging area 5. The processing circuit 8 processes an output of the imaging area 5. The Imaging area 5 has a multiplicity of pixels P which are arranged on the semiconductor substrate 3 in one or two dimensions. In Fig. 1, the pixels P (m, n) are shown in m rows and n columns (m and n are natural numbers). Each of the pixels P (m, n) includes a light receiving unit 9 and a current injection circuit 20. The imaging area 5 detects the reflected light from the object for each of the pixels P. Then, the distance for each of the pixels P of the image of the object is obtained by obtaining the time obtained from the irradiation of the light to the arrival of the reflected light for each of the pixels P. The distance sensor 1A is a charge distribution type distance sensor and obtains the time from the irradiation of the light to the arrival of the reflected light according to a ratio of amounts of charge distributed in two positions within each of the pixels P. FIG. 2 is a plan view of the light receiving unit 9 of each of the pixels P (m, n) of the distance sensor 1A shown in FIG. 1. 3 and 4 are cross-sectional views taken along a line III-III and a line IV-IV of FIG. 2, respectively, and illustrate cross-sectional configurations of the light receiving unit 9. In addition, FIG. 3 also illustrates a light source unit 30. As shown in Fig. 2, the light receiving unit 9 of the present embodiment includes a transfer electrode 11 (first transfer electrode), a transfer electrode 12 (second transfer electrode), a transfer electrode 13 (fifth transfer electrode), a photo gate electrode 14, signal extraction electrodes 15 and 16 and a charge discharge electrode 17. In Fig. 2, the number of the transfer electrodes 11 and 12 and the signal extraction electrodes 15 and 16 are two, but may be one. In FIG. 2, the number of the transfer electrode 13 and the charge discharge electrode 17 is two in each case, but can also be one. As shown in Fig. 3, the light receiving unit 9 further includes a photosensitive area 9a, a charge collection area 9b (first charge collection area) and a charge collection area 9c (second charge collection area). The photosensitive area 9a receives reflected light L2 and generates charges according to the amount of light. The charge collecting regions 9b and 9c are arranged so as to adjoin the photosensitive region 9a in a state of inserting the photosensitive region 9a. Each of the charge collecting areas 9b and 9c collects charges from the photosensitive area 9a, so that the charges are stored in each storage node connected thereto. Incidentally, the photosensitive region 9a is arranged between the charge collecting regions 9b and 9c in Fig. 3, but the charge collecting regions 9b and 9c may adjoin one side of the photosensitive region 9a, and there is no restriction on a positional relationship between them. In particular, the semiconductor substrate 3 is made of a highly concentrated P-type (second conductivity type) semiconductor, and the light receiving unit 9 of each of the pixels P (m, n) has a low-concentration P-type (second conductivity type) surface area 3c, which is provided on a surface side 3a of the semiconductor substrate 3. In addition, an insulating layer 41 is formed on the surface 3a of the semiconductor substrate 3 and the photo gate electrode 14 is formed on the surface region 3c between the charge collecting regions 9b and 9c, the insulating layer 41 being arranged in between. A region within the surface region 3c, which is arranged immediately below the photo gate electrode 14, is the photosensitive region 9a. A potential of the photosensitive region 9a is controlled by a voltage applied to the photo gate electrode 14. If necessary, a slightly positive DC voltage is applied to the photo gate electrode 14. As a result, electron-hole pairs are generated in response to the incidence of light on the photosensitive region 9a. CH 713 891 B1 The charge collection regions 9b and 9c are highly concentrated n-type (first conductivity type) regions formed on the surface region 3c side of the calf conductor substrate 3. The charge accumulation areas 9b and 9c are also referred to as sliding diffusion areas or charge storage areas. An n-type semiconductor has electrons as carriers in the electrically neutral state and is positively ionized in the absence of the carriers. This means that each band structure of the highly concentrated n-charge collecting regions 9b and 9c has a shape that is strongly recessed downwards and forms a potential well. The signal extraction electrode 15 is formed on the charge collection area 9b and the signal extraction electrode 16 is formed on the charge collection area 9c. The signal extraction electrodes 15 and 16 are in contact with the charge collecting regions 9b and 9c through openings formed in the insulation layer 41. The transfer electrode 11 is disposed on an area between the photosensitive area 9a and the charge collecting area 9b. The transfer electrode 12 is arranged on an area between the photosensitive area 9a and the charge collecting area 9c. When a positive potential (on potential) is applied to the transfer electrode 11, a potential of the area immediately below the transfer electrode 11 has an intermediate size between a potential of the photosensitive area 9a and a potential of the charge accumulation area 9b. In this way, potential steps are formed from the photosensitive area 9a to the charge collection area 9b, and electrons fall into the potential well of the charge collection area 9b (the charges are stored in the pot). Similarly, when a positive potential (on potential) is applied to the transfer electrode 12, a potential of the area immediately below the transfer electrode 12 has an intermediate size between the potential of the photosensitive area 9a and a potential of the charge accumulation area 9c. Therefore, potential steps are formed from the photosensitive area 9a to the charge collecting area 9c, and electrons fall into the potential well of the charge collecting area 9c. Incidentally, the structure of providing the signal extraction electrodes 15 and 16 on the charge collecting areas 9b and 9c for extracting signals is adopted in the present embodiment, but it is also possible to separately provide a highly concentrated area for signal extraction which is connected to the charge collecting areas 9b and 9c and place other transfer electrodes on areas between the highly concentrated area and each of the charge collecting areas 9b and 9c and provide a signal extraction electrode on the highly concentrated area to extract a signal. The light source unit 30 is a light irradiation unit configured to irradiate an object B with light L1, and includes a light source 31, a light source drive circuit 32 and a control circuit 33. The light source 31 includes a semiconductor light emitting element such as a laser element or a light emitting diode. The light source drive circuit 32 drives the light source 31 at a high frequency. The control circuit 33 outputs a drive clock of the light source drive circuit 32. In addition, the object B is periodically and repeatedly irradiated with pulsed light that has been subjected to intensity modulation of a square wave from the light source 31. The irradiation light L1 from the light source 31 is reflected from a surface of the object B and strikes each of the pixels P (m, n) in the imaging area 5 of the distance sensor 1A from a back surface 3b on the side of the semiconductor substrate 3 as reflected light L2 , Incidentally, a plurality of imaging lenses corresponding to the pixels P (m, n) may be arranged to face the back surface 3b of the semiconductor substrate 3. As shown in Fig. 4, the light receiving unit 9 further has two charge collecting areas 9d (fifth charge collecting areas). The charge collecting regions 9d are formed in the surface region 3c of the semiconductor substrate 3 and are arranged adjacent to the photosensitive region 9a in the state in which the photosensitive region 9a is inserted. Then, the charge discharge electrode 17 is formed on the charge collecting area 9d. The charge discharge electrode 17 is in contact with the charge collecting region 9d through the opening formed in the insulation layer 41. The transfer electrode 13 is arranged on an area between the photosensitive area 9a and the charge collecting area 9d. When a positive potential (on potential) is applied to the transfer electrode 13, the charge moves from the photosensitive area 9a to the charge accumulation area 9d, and the charges are stored in a potential well of the charge accumulation area 9d. Incidentally, a specific configuration of the charge accumulation area 9d is identical to that of the charge accumulation areas 9b and 9c. Fig. 5A is a diagram illustrating an example of a temporal change in the intensity of the reflected light on a particular pixel P (m, n). 5B is a diagram illustrating a change over time in the voltage applied to the transfer electrode 11. 5C is a graph illustrating a change over time in the voltage applied to the transfer electrode 12. As shown in FIG. 5A, the reflected light L2 falls on the pixel P (m, n), which is delayed from a light illumination time L by a time t that corresponds to a distance from the object B. As shown in FIG. 5B, the transfer electrode 11 is set to the on potential in a first time period H1 after the light irradiation and to the off potential in a second time period H2 after the first time period. In addition, the transmission electrode 12 is set to the off potential in the first time period H1 and to the on potential in the second time period H2, as shown in FIG. 5C. It is then assumed that part of the reflected light L2 (an area A1 of the graphic in the drawing) strikes the pixel P (m, n) within the first period H1. At this time, since the transfer electrode 12 is at the off potential and the transfer electrode 8 CH 713 891 B1 trode 11 is set to the on potential, the charges generated in the light-sensitive area 9a migrate into the charge collection area 9b and are stored there. The remaining part of the reflected light L2 (an area A2 of the graphic in the drawing) strikes the pixel P (m, n) within the second time period H2. At this time, since the transfer electrode 11 is set to the off potential and the transfer electrode 12 is set to the on potential, the charges generated in the photosensitive region 9a migrate to the charge accumulation region 9c and are stored there. Therefore, it is possible to recognize the delay time t, that is, the distance to the object B, by considering a ratio between an amount of charge stored in the charge collecting area 9b (a charge amount of the storage node electrically coupled to the charge collecting area 9b) and one in the charge collecting area 9c stored charge amount (a charge amount of the storage node that is electrically coupled to the charge accumulation area 9c). Here, the processing circuit 8 of the present embodiment can be configured to output a difference between these amounts of charges by causing the charges stored in the charge accumulating area 9b and the charges stored in the charge accumulating area 9c to balance each other. In this case, too, it is possible to know the relationship between the amount of charge stored in the charge collection area 9b and the amount of charge stored in the charge collection area 9c, provided that the sum of the charge amounts stored in the charge collection areas 9b and 9c (the sum of the charge amounts of the charge collection areas 9b and 9c coupled storage nodes) is known. In the following, a driving system of the imaging area 5 (a driving system of the distance sensor according to the present embodiment) will be described, which is configured to know the sum of the amounts of charges stored in the charge collecting areas 9b and 9c. According to the present embodiment, the sensor drive circuit 7 drives the transfer electrodes 11 and 12 by executing a plurality of time-divided frames (each of which represents a drive pattern of a transfer electrode) in succession. FIG. 6 is a view illustrating the driving system of the imaging area 5 using the sensor driving circuit 7. As shown in FIG. 6, in the drive system of the present embodiment, the processing in each of the first and second commands F1 and F2 is performed while the commands F1 and F2 are repeated alternately. 6 also illustrates the processing contents within the respective commands F1 and F2. Within the commands F1 and F2, a storage command F3 for charge storage in the charge collection areas 9b and 9c (charge storage in storage nodes which are respectively coupled to the charge collection areas 9b and 9c) and a read command F4 for charge readout from the charge collection areas 9b and 9c are repeated. 7A and 7B are timing charts illustrating the operation of the transfer electrodes 11 to 13 in the store command F3. FIG. 7A illustrates the timing diagram in the first instruction F1 and FIG. 7B the timing diagram in the second instruction F2. 7A and 7B illustrate a drive clock CL of the light source driver 32 that is output from the control circuit 33 (that is, a change over time of an intensity of the pulsed light output of the light source 31), a drive voltage Vtx-i applied to the transmission electrode 11 the transmission electrode 12 applied drive voltage Vtx 2 and a drive voltage Vtxr applied to the transmission electrode 13. In the memory command F3, the drive voltages Vtx-i and Vtx 2 are repeatedly switched between the on potential and the off potential twice each time the driver clock CL rises once at a specific cycle T. The cycle T is set to twice the switch-on time t L of the drive clock CL (for example T = 2t L ). In addition, a turn-on time (a time period in which a drive voltage is set to the on-potential) of the drive voltages Vtx-i and Vtx 2 in each cycle is equal to the turn-on time t L of the drive clock CL. In particular, the uniform time intervals t 0 , ti, ... and t 9 are defined in the memory command F3 of the first command F1 and the second command F2, as shown in FIGS. 7A and 7B. An interval between these times is half the one-time irradiation time t L of the irradiation light L1. At this time, the light source unit 30 emits the irradiation light L1 for the times L to t 3 . Then the sensor control circuit 7 sets the drive voltage Vtx-i to the on potential between times t 0 and t 2 and between times t 4 and t 6 and the drive voltage Vtx 2 to the on potential between times t 2 and t 4 and between times t 6 and t 8 in the first command F1, as shown in Fig. 7A. In addition, the sensor drive circuit 7 sets the drive voltage Vtx-i to the on potential between times L and t 3 and between times t 5 and t 7 and the drive voltage Vtx 2 to the on potential between times t 3 and t 5 and between times t 7 and t 9 in the second command F2, as shown in Fig. 7B. Incidentally, the drive voltage Vtxr applied to the transmission electrode 13 is set to the on potential, except for a period in which the other drive voltages Vtx-i and Vtx 2 are first set to the on potential and then finally to the off potential can be set. This means that the drive voltage Vtxr is set to the off potential between times t 0 and t 8 in the first command F1, to the off potential between times L and t 9 in the second command F2 and to on in the other periods -Potential. In other words, the above process is carried out as follows. In the first command F1, the driving voltage Vtx-i rises at a time which is (t L / 2) earlier than the rising time of the driving clock CL. In the following, a phase of the drive voltage Vtx-i is set to 0 ° in the first command F1. The drive voltage Vtx 2 rises by t L at a later time than the rise time of the drive voltage Vtx- |. In other words, a phase of the driving voltage CH 713 891 B1 Vtx 2 in the first command F1 is 180 °. In the second command F2, the driving voltage Vtx-i increases at the same time as the rising time of the driving clock CL. In other words, a phase of the driving voltage Vtx-i in the second command F2 is 90 °. In addition, the drive voltage Vtx 2 rises at a later time by t L than the rise time of the drive voltage Vtx-i. In other words, a phase of the drive voltage Vtx 2 in the second command F2 is 270 °. Fig. 8 is a view here that overlaps the timing diagrams of the first command F1 and the second command F2 in Figs. 7A and 7B for the single drive clock CL to facilitate understanding. A driving voltage Vtx-i (1) and a driving voltage Vtx 2 (1) respectively represent the driving voltages Vtx-i and Vtx 2 in the first command F1, and a driving voltage Vtx-i (2) and a driving voltage Vtx 2 (2) each represent the drive voltages Vtx-i and Vtx 2 in the second command F2. FIGS. 9 and 10 further illustrate a diagram of a light receiving pulse waveform of the reflected light L2 in the time chart shown in FIG. 8. As shown in FIG. 9, it is assumed that the reflected light L2 strikes the pixel P (m, n) after a time (t L / 3) that has passed since the object B was irradiated with light L1. At this time, in the first command F1, charges corresponding to the area of an area A3 in Fig. 9 are stored in the charge collecting area 9b and a charge corresponding to the area of an area A4 in the charge collecting area 9c. Assuming that the total charge amount generated by the reflected light is Q, Q is a charge amount stored in the charge collection area 9b and Q / 6 and a charge amount (5 x Q / 6) stored in the charge collection area 9c. In addition, in the second command F2, charges corresponding to the area of an area A5 in the drawing are stored in the charge collecting area 9b and charges corresponding to the area of an area A6 in the charge collecting area 9c. At this time, an amount of charge stored in the charge accumulation area 9b is (2 x Q / 3) and a charge amount stored in the charge accumulation area 9c is Q / 3. Subsequently, the amount of charge Q / 6 of the charge collecting area 9b in the first command F1 is subtracted from the amount of charge (5 χ Q / 6) of the charge collecting area 9c in the first command F1, whereby a value of (2 x Q / 3) is obtained. Likewise, the amount of charge (2 x Q / 3) of the charge accumulation area 9b in the second command F2 is subtracted from the charge amount Q / 3 of the charge accumulation area 9c in the second command F2, whereby a value of -Q / 3 is obtained. Then, when absolute values of these values are added, the total charge amount Q generated by the reflected light L2 is obtained. Next, it is assumed that the reflected light L2 strikes the pixel P (m, n) after a time (3 xt L / 4) that has passed since the object was irradiated with the light L1, such as shown in Fig. 10. At this time, in the first command F1, charges corresponding to the area of an area A7 in the drawing are stored in the charge collecting area 9b and charges corresponding to the area of an area A8 are stored in the charge collecting area 9c. At this time, a charge amount stored in the charge collection area 9b is Q / 4 and a charge amount stored in the charge collection area 9c (3 x Q / 4). In addition, in the second command F2, charges corresponding to the area of an area A9 in the drawing are stored in the charge collecting area 9b and charges corresponding to the area of an area A10 in the charge collecting area 9c. At this time, a charge amount stored in the charge collection area 9b is Q / 4 and a charge amount stored in the charge collection area 9c (3 χ Q / 4). Subsequently, the amount of charge Q / 4 of the charge collecting area 9b in the first command F1 is subtracted from the amount of charge (3 χ Q / 4) of the charge collecting area 9c in the first command F1, whereby a value of Q / 2 is obtained. Likewise, the amount of charge Q / 4 of the charge collecting area 9b in the second command F2 is subtracted from the amount of charge (3 χ Q / 4) of the charge collecting area 9c in the second command F2, whereby a value of Q / 2 is obtained. If absolute values of these values are then added, the total amount of charge Q generated by the reflected light L2 is obtained. As can be seen from the example above, it is possible to obtain the total amount of charge Q generated by the reflected light L2 by taking the absolute value of the value obtained by subtracting the amount of charge collected in phase 0 ° , ie the times t 0 to t 2 and t 4 to t 6 , from the amount of charge collected in phase 180 °, i.e. the times t 2 and t 4 and t 6 and t 8 , and the absolute value of the value obtained by Subtraction of the amount of charge collected in phase 90 °, that is, times L and t 3 and t 5 and t 7 , from the amount of charge collected in phase 270 °, that is, times t 3 and t 5 and t 7 and t 9 is added. Therefore, it is possible to know the delay time t, that is, the distance to the object B, by looking at the ratio of the amounts of charge stored in the charge collecting areas 9b and 9c (the ratio of the amount of charges stored in the storage nodes, each to the charge collecting areas 9b and 9c are coupled) based on the total charge amount Q thus obtained and the difference between the charge amounts stored in the storage nodes, which are respectively coupled to the charge accumulation areas 9b and 9c obtained from the processing circuit 8. [0049] The distance calculation method described above will be described more generally. 11A is a graph illustrating a relationship between a value obtained by subtracting the amount of charge of the storage node coupled to the charge accumulation area 9b from the charge amount of the storage node coupled to the charge accumulation area 9c (i.e., an output value of each of the pixels P (m, n )) and the time t from the irradiation of the light L1 to the folding of the reflected light L2 (that is the distance to the object B) is obtained. In Fig. 11A, a graph G11 shows the output value in the first instruction F1 and a graph G12 shows the output value in the second instruction F2. In addition, the output value is normalized in order to obtain a maximum value of 1 and a minimum value of -1. As the diagram G11 of FIG. 11A shows, in the first command F1 the output value increases from 0 to 1 in a section D1 from 0 <t <t <t L / 2, the output value decreases from 1 to 0 in one Section D2 of t L / 2 <t <t <t L , the output value continues to decrease from 0 to -1 in section D3 of t L <t <t <(3 χ t L / 2), and the output value increases from -1 CH 713 891 B1 to 0 in a section D4 of (3 xt L / 2) <t <2t L. In addition, as shown in diagram G12, in the second command F2 the output value increases from -1 to 0 in section D1, the output value further increases from 0 to 1 in section D2, the output value decreases from 1 to 0 in section D3 and the output value further decreases from 0 to -1 in section D4. That is, as shown in a graphic of FIG. 11B, the signs of the output values in the first command F1 and in the second command F2 in section D1 become (-) and (+), (+) and ( +) in section D2 to (+) or (-) in section D3 to (+) or (-) and become (-) or become (-) in section D4. Therefore, it is possible to determine the section among the sections D1 to D4 in which the time t from the irradiation of the light L1 to the incidence of the reflected light L2 based on a combination of the signs of the output values in the first command F1 and the second command F2 is present. The absolute values of the respective output values of the first command F1 and the second command F2 are then obtained, as shown in FIG. 11C. Specifically, the sign of the output value (graphic G12) of the second command F2 in section D1 is inverted, the sign of the output value (graphic G11) of the first command F1 in section D2 is inverted, the sign of the output values of the first command F1 and the second command F2 ( Graphics G13 and G14 in the drawing) inverted in section D3. This gives a diagram G21 with a constant value regardless of the time t by adding the absolute values of the respective output values of the first command F1 and the second command F2. This graph G21 shows the total amount of charge (the amount of charge Q described above) generated by the reflected light L2. The sign of the output value of the second command F2 in sections D3 and D4 (graphic G12 in FIG. 11A) is then inverted, as shown in FIG. 12A. As a result, both the output value of the second command F2 in sections D1 and D2 and the output value of the second command F2 in sections D3 and D4 have a positive edge with respect to time t. Then, both the output value of the second command F2 in sections D1 and D2 and the output value of the second command F2 in sections D3 and D4 are multiplied by%, as shown in Fig. 12B. Finally, a corresponding offset value is added to each of the output values of the second command F2 in sections D1 and D2 and the output value of the second command F2 in sections D3 and D4, whereby a linear diagram G22 is obtained, in which the output value of Obis 1 in a range of 0 <t <2t L increases as shown in Fig. 12C. This makes it possible to know the time t, that is to say the distance to the object B, based on the diagram G21 and the diagram G22. Incidentally, the order of the respective operations shown in Figs. 12A to 12C is not limited to that described above and can be performed in a different order. Alternatively, the operations shown in FIGS. 12A to 12C can also be performed simultaneously. In addition, in the description of FIGS. 12A to 12C, the output value of the second command F2 is used, but the graph G22 of FIG. 12C can be calculated with the output value of the first command F1. According to the distance sensor 1A and the control method according to the present embodiment, it is possible to obtain the time t, that is to say the distance to the object B, based on the difference between the amounts of charge stored in the storage nodes, each as described above are coupled to the charge collection regions 9b and 9c. Therefore, it is possible to adopt the method of using the injection of the same amount of electricity into each storage node, and as a result, it is possible to avoid the saturation of each storage node. An example of a circuit configuration for injecting the same amount of current into each storage node is described in detail below. Fig. 13 is a circuit diagram showing a detailed configuration of the current injection circuit 20 shown in Fig. 1. As shown in FIG. 13, the current injection circuit 20 of the present embodiment includes a voltage generation circuit 21 and the transistors 22a, 22b, 23a and 23b. Transistors 22a, 22b, 23a and 23b are field effect transistors, for example p-channel MOSFETs. The voltage generating circuit 21 is connected between a supply potential line 34 and a reference potential line GND with a lower potential than the supply potential line 34. The voltage generating circuit 21 generates control voltages VCi and VC 2 which correspond to a larger one between the amounts of charges stored in the charge accumulation areas 9b and 9c. In particular, the voltage generating circuit 21 includes a pair of transistors 24 and a current source 25 which are connected in series between the supply potential line 34 and the reference potential line GND. In addition, the voltage generating circuit 21 has the buffer circuits 27 and 28. The pair of transistors 24 includes transistors 24a and 24b. Transistors 24a and 24b are field effect transistors, for example p-channel MOSFETs. A current terminal (first current terminal) of the transistors 24a and 24b is short-circuited and electrically connected to the supply potential line 34 via the current source 25. The other current terminals (second current terminals) of the transistors 24a and 24b are short-circuited to one another and electrically connected to the reference potential line GND. A control terminal of the transistor 24a is electrically connected to the signal extraction electrode 15 in the charge collecting region 9b via a storage node 26a. A control terminal of the transistor 24b is electrically connected to the signal extraction electrode 16 on the charge collecting region 9c via a storage node 26b. The storage node 26a stores the charge collected in the charge collection area 9b and the storage node 26b stores the charge collected in the charge collection area 9c. CH 713 891 B1 The current source 25 includes a transistor 25a. Transistor 25a is a field effect transistor, for example a p-channel MOSFET. A current terminal (first current terminal) of the transistor 25a is electrically connected to the supply potential line 34. The other current terminal (second current terminal) of transistor 25a is electrically connected to the first current terminal of each of transistors 24a and 24b. A predetermined bias voltage ν Ί is applied to a control terminal of the transistor 25a. Incidentally, the current source can also include another transistor which is connected in parallel with transistor 25a. The transistor 22a supplies a current for eliminating a stray light component in order to avoid saturation of the storage node 26a on the storage node 26a. One current terminal (first current terminal) of transistor 22a is connected to supply potential line 34 and the other current terminal (second current terminal) is connected to storage node 26a via transistor 23a. A control terminal of the transistor 22a is electrically connected via the buffer circuit 27 to a node N1 between the pair of transistors 24 and the current source 25. The transistor 22b supplies a current for eliminating the stray light component to the storage node 26b. One current terminal (first current terminal) of transistor 22b is connected to supply potential line 34 and the other current terminal (second current terminal) is connected to storage node 26b via transistor 23b. A control terminal of transistor 22b is connected to node N1 via buffer circuit 28. The transistor 23a is connected in a cascade manner to the transistor 22a and prevents an operation of the transistor 22a from being impaired by a potential fluctuation in the storage node 26a. In particular, one current terminal (first current terminal) of transistor 23a is connected to the second current terminal of transistor 22a, and the other current terminal (second current terminal) of transistor 23a is connected to storage node 26a. A predetermined bias voltage V 3 is applied to a control terminal of transistor 23a. The transistor 23b is connected in a cascade manner to the transistor 22b and prevents an operation of the transistor 22b from being impaired by a potential fluctuation in the storage node 26b. In particular, one current terminal (first current terminal) of transistor 23b is connected to the second current terminal of transistor 22b, and the other current terminal (second current terminal) of transistor 23b is connected to storage node 26b. A predetermined bias voltage V 4 is applied to a control terminal of transistor 23b. Otherwise, the bias voltage V 3 and the bias voltage V 4 are the same in one example. The buffer circuit 27 shifts a potential of the node N1 to generate a control voltage VCi and provides the generated control voltage to the control terminal of the transistor 22a. Buffer circuit 27 is configured to accommodate, for example, a source sequencer. In particular, the buffer circuit 27 has the transistors 27a and 27b connected in series. One current terminal (first current terminal) of transistor 27a is connected to supply potential line 34, and the other current terminal (second current terminal) is connected to one current terminal (first current terminal) of transistor 27b. The other current terminal (second current terminal) of the transistor 27b is connected to the reference potential line GND. A predetermined bias voltage V 5 is applied to a control terminal of transistor 27a. The potential of the node N1 is fed to a control terminal of the transistor 27b. The buffer circuit 27 outputs the control voltage VC-i with a size that corresponds to the potential of the node N1 from the node between the transistors 27a and 27b. The buffer circuit 28 shifts the potential of the node N1 to generate a control voltage VC 2 and provides the generated control voltage to the control terminal of the transistor 22b. Buffer circuit 28 is configured to accommodate, for example, a source sequencer. In particular, the buffer circuit 28 has the transistors 28a and 28b connected in series. One current terminal (first current terminal) of transistor 28a is connected to supply potential line 34, and the other current terminal (second current terminal) is connected to one current terminal (first current terminal) of transistor 28b. The other current terminal (second current terminal) of transistor 28b is connected to the reference potential line GND. A predetermined bias voltage V 6 is applied to a control terminal of transistor 28a. The potential of node N1 is fed to a control terminal of transistor 28b. The buffer circuit 28 outputs the control voltage VC 2 with a magnitude that corresponds to the potential of the node N1 from the node between the transistors 28a and 28b. The magnitudes of the bias voltages V 5 and V 6 are set such that the amount of current supplied by transistor 22a to storage node 26a and the amount of current supplied by transistor 22b to storage node 26b are the same and, for example, V 5 = V 6 can be set. Incidentally, the buffer circuits 27 and 28 can be omitted. In this case, the control terminals of transistors 22a and 22b are connected directly to node N1, and the potential of node N1 is supplied to these control terminals as control voltage VC-i and VC 2 . The current injection circuit 20 further includes the reset circuits 35 and 36. The reset circuit 35 has a transistor 35a, and the reset circuit 36 has a transistor 36a. A reset potential Vr is applied to a current terminal (first current terminal) of the transistors 35a and 36a. The other current terminal (second current terminal) of transistor 35a is connected to storage node 26a and the other current terminal (second current terminal) of transistor 36a is connected to storage node 26b. A reset signal Sr is input to the control terminals of transistors 35a and 36a, and the charges of storage nodes 26a and 26b are discharged when transistors 35a and 36a are turned on. CH 713 891 B1 Operation of the current injection circuit 20 with the above configuration will be described. When the reflected light L2 strikes the pixel P (m, n), the charges flow into the charge collecting areas 9b and 9c in the ratio corresponding to the distance to the object B (see Figs. 5A to 5C). In addition, the charges corresponding to the size of the stray light incident on the pixel P (m, n) also flow into the charge collecting areas 9b and 9c. However, when the on-time of the drive voltage applied to the transfer electrode 11 and the on-time of the drive voltage applied to the transfer electrode 12 are the same, the amounts of charges that flow into the charge accumulation areas 9b and 9c due to the stray light are the same. As a result, the potentials of the storage nodes 26a and 26b have sizes that correspond to the amounts of charge that flow into the charge collection areas 9b and 9c, respectively. Then, when the charges continue to flow into the charge accumulation areas 9b and 9c in the storage command F3 (see FIG. 6) and one of the potentials of the storage nodes 26a and 26b exceeds a turn-on voltage, one of the transistors 24a and 24b begins a current corresponding to the potential of the one storage node to flow. Therefore, the potential of the node N1 has a size which corresponds to a larger amount between the amounts of charge stored in the charge collecting areas 9b and 9c (storage nodes 26a and 26b). The control voltages VC-i and VC 2 with sizes corresponding to the potential of the node N1 are output to the control terminals of the transistors 22a and 22b, respectively. The transistors 22a and 22b receive the above control voltages VC-i and VC 2 at their control terminals and cause current to flow in accordance with any size of the control voltages VC-i and VC 2 . Since the predetermined bias voltages V 3 and V 4 are constantly applied to the control terminals of the transistors 23a and 23b, the current from each of the transistors 23a and 23b is fed into each of the storage nodes 26a and 26b. This compensates for the same amount of charge at the storage nodes 26a and 26b and avoids the saturation of the storage nodes 26a and 26b (charge collection areas 9b and 9c) caused by the stray light. Effects that can be achieved by the distance sensor 1A and the driving method of the distance sensor 1A according to the present embodiment as described above will be described. In the present embodiment, the distance to the object B can be obtained based on the difference between the amounts of charges stored in the storage nodes, which are coupled to the charge collecting areas 9b and 9c as described above. Therefore, it is possible to use the method of injecting the same amount of electricity into each storage node using the current injection circuit 20, and as a result, it is possible to avoid the saturation of each storage node. In addition, in the present embodiment, since pulsed light is used as the irradiation light L1, it is easy to have a period of time for discharging the charges compared to the method described in Non-Patent Document 1 in which the triangular wave light is used, set. Thus, it is possible to reduce the shot noise in the present embodiment. In addition, in the present embodiment, the light emission state of the light source is intermittent compared to the output of the triangular light, so that it is possible to increase the intensity of the irradiation light. This means that it is possible to increase the intensity of the irradiation light in relation to the intensity of the interference light (ie a signal-to-noise ratio). In addition, the selectivity of the light source, such as a duty cycle and a quantity of light, when outputting shock-like light, such as the pulsed form, has the advantage of a high selectivity (selection is easy) compared to continuous light, such as triangular wave light. Furthermore, in a distance sensor described in Patent Document 1, it is only possible to measure up to a distance that corresponds to a delay time that corresponds to the irradiation time of the irradiation light L1. On the other hand, according to the present embodiment, it is possible to measure up to a distance that corresponds to a delay time that is twice the irradiation time of the irradiation light L1 (the time t L in FIGS. 7A and 7B). Furthermore, the sensor driving circuit 7 can drive the transmission electrode 13 in each of the commands F1 and F2 as described above as in the present embodiment. This makes it possible to discharge the charges generated by the stray light with the transfer electrode 13, except for a period in which the transfer electrodes 11 and 12 are driven. This makes it possible to further suppress the saturation caused by the stray light and to reduce the shot noise caused by the stray light and thus to improve resistance to the stray light and the accuracy of the distance measurement. Furthermore, in the current injection circuit 20 of the present embodiment, cascade devices such as the transistors 23a and 23b are connected between each of the transistors 22a and 22b and each of the storage nodes 26a and 26b. As a result, the respective potentials of the transistors 22a and 22b and the storage nodes 26a and 26b are separated. Thus, even if there is a potential difference between the storage node 26a and the storage node 26b, the influence on the source-sink voltages of the transistors 22a and 22b is suppressed and it is possible to equate the source-sink voltages of these transistors 22a and 22b. In addition, the difference in the amounts of current fed from each of the transistors 22a and 22b to each of the storage nodes 26a and 26b (charge accumulation areas 9b and 9c) is reduced, and it is possible to accurately add these amounts of injection current in a substantially uniform size Taxes. Therefore, it is possible to have an error at the time of outputting the difference CH 713 891 B1 between the charge quantities stored in the charge accumulation areas 9b and 9c in the processing circuit 8, and to improve the accuracy of the measured distance. (First modification) Figs. 14A and 14B are views illustrating timing charts of a driving method according to a first modification of the above embodiment. The sensor drive circuit 7 of the above embodiment can drive the transfer electrodes 11 and 12 based on the time charts shown in FIGS. 14A and 14B instead of the time charts shown in FIGS. 7A and 7B. [0076] A difference between the timing chart of the first modification and the timing chart of the above embodiment is the length of an on-time of the driving voltages Vbq and Vtx 2 . In the above embodiment, the on-time of the driving voltages Vtx-ι and Vtx 2 is equal to the on-time of the driving clock CL (ie the irradiation time of the irradiation light L1) t L ; the on-time of the drive voltages Vtx-ι and Vtx 2 is, however, half the time t L (ti_ / 2) at the first change. In particular, the uniform time intervals t 0 , ti, ... and t 8 are defined in the memory command F3 of the first command F1 and the second command F2, as shown in FIGS. 14A and 14B. An interval between these times is half the one-time irradiation time t L of the irradiation light L1. At this time, the light source unit 30 emits the irradiation light L1 for the times t-ι to t 3 . The sensor control circuit 7 then sets the drive voltage Vtx-ι to the on potential between times t 0 and t-ι and between times t 4 and t 5 and the drive voltage Vtx 2 to the on potential between sides t 2 and t 3 and between times t 6 and t 7 in the first command F1, as shown in FIG. 14A. In addition, the sensor control circuit 7 sets the drive voltage Vtx-ι to the on potential between times t-ι and t 2 between times t 5 and t 5 and the drive voltage Vtx 2 to the on potential between times t 3 and t 4 and between times t 7 and t 8 in the second command F2, as shown in FIG. 14B. Incidentally, the drive voltage Vtxr applied to the transmission electrode 13 is set to the on potential, with the exception of a period in which the other drive voltages Vtx-ι and Vtx 2 are initially set to the on potential and then finally to the off. Potential can be set. That is, the drive voltage Vtxr is in the first command F1 to the off potential between times t 0 and t 7 , in the second command F2 to the off potential between times t-ι and t 8 and in the other periods A potential set. 15A and 15C are views for describing a distance calculation method in the first modification. 15A is a diagram illustrating a relationship between a value obtained by subtracting a charge amount of a storage node coupled to the charge accumulation area 9b from a charge amount of a storage node coupled to the charge accumulation area 9c (i.e., an output value of each of the pixels P (m, n )) and the time t from the irradiation of the light L1 to the incidence of the reflected light L2 (ie a distance from the object B) is obtained. In Fig. 15A, a graph G41 shows the output value in the first instruction F1 and a graph G42 shows the output value in the second instruction F2. Incidentally, the output value is standardized in order to achieve a maximum value of 1 and a minimum value of -1. As the diagram G41 of FIG. 15A shows, in the first command F1 the output value is constant as 1 in a section D1 from 0 <t <t <t L / 2, the output value decreases from 1 to -1 in a section D2 of t L / 2 <t <t <t L , the output value is constant as -1 in a section D3 of t L <t <t <(3 xt L / 2), and the output value increases from -1 to 1 in a section D4 of (3 xt L / 2) <t <2t L. In addition, as shown in diagram G42, in the second command F2 the output value increases from -1 to 1 in section D1, the output value is constant as 1 in section D2, the output value decreases from 1 to -1 in section D3, and the Output value is constant as -1 in section D4. Here, absolute values of the respective output values of the first command F1 and the second command F2 are obtained, and the output value of the larger one is selected between the output values of the first command F1 and the second command F2. A diagram G51 with a constant value regardless of the time t is then obtained, as shown in FIG. 15B. This graph G51 represents half of the total amount of charge generated by the reflected light L2. Meanwhile, in a section in which the output value (graph G41) of the first command F1 is smaller than the output value (graph G42) of the second command F2 under the respective sections D1 to D4, a sign of a smaller absolute value between the output values of the first command F1 and the second command F2 inverted. In the example of FIG. 15A, the signs of the output value of the first command F1 in section D2 and the output value of the second command F2 in section D3 are inverted. As a result, both the output value of the second command F2 in sections D1 and D3 and the output value of the first command F1 in sections D2 and D4 have a positive edge with respect to time t. Then, both the output value of the second command F2 in sections D1 and D3 and the output value of the first command F1 in sections D2 and D4 are multiplied by%, as shown in Fig. 15B. Finally, a corresponding shift value is added to each of the output values of the second command F2 in sections D1 and D3 and the output value of the first command F1 in sections D2 and D4, whereby a linear diagram G52 is obtained in which the output value is from 0 to 1 increases in a range of 0 <t <2t L as shown in Fig. 15C. This makes it possible to know the time t, that is to say the distance to the object B, based on the diagram G51 and the diagram G52. Incidentally, the order is that in Figs. 15A to 15C The operations shown in CH 713 891 B1 are not limited to those described above and can be performed in a different order. Alternatively, the operations shown in Figs. 15A to 15C can be performed simultaneously. According to this first modification, the distance to the object B can be obtained based on the difference between the amounts of charge stored in the storage nodes, which are respectively coupled to the charge collecting areas 9b and 9c, similarly to the above embodiment. Therefore, it is possible to adopt the method of using the injection of the same amount of electricity into each storage node, and as a result, it is possible to avoid the saturation of each storage node. In addition, it is also possible to adequately achieve the other effects of the above embodiment. In addition, the sensor drive circuit 7 can drive the transmission electrode 13 in each of the commands F1 and F2 as described above in the first modification. This makes it possible to further suppress the saturation caused by stray light and to reduce the shot noise caused by the stray light and thus to improve resistance to the stray light and the accuracy of the distance measurement. (Second modification) Fig. 16 is a plan view illustrating a light receiving unit 9A according to a second modification of the above embodiment. As shown in FIG. 16, the light receiving unit 9A of the second modification includes the transmission electrode 11 (first transmission electrode), the transmission electrode 12 (second transmission electrode), a transmission electrode 51 (third transmission electrode), and a transmission electrode 52 (fourth transmission electrode), respectively. These transfer electrodes 11, 12, 51 and 52 are arranged around the photo gate electrode 14 so as to be aligned with the photo gate electrode 14. Incidentally, in the present embodiment, the photo gate electrode 14 is arranged between the transfer electrode 11 and the transfer electrode 12, and the photo gate electrode 14 is arranged between the transfer electrode 51 and the transfer electrode 52, and a positional relationship between the transfer electrodes 11, 12, 51 and 52 is not restricted as long as the transfer electrodes are aligned with the photo gate electrode 14. In addition, the light receiving unit 9A has one of the signal extraction electrodes 15, 16, 55 and 56, respectively. The transfer electrode 11 is arranged between the signal extraction electrode 15 and the photo gate electrode 14, the transfer electrode 12 is arranged between the signal extraction electrode 16 and the photo gate electrode 14, the transfer electrode 51 is arranged between the signal extraction electrode 55 and the photo gate electrode 14, and the transfer electrode 52 is between the signal extraction electrode 56 and the photo gate electrode 14 are arranged. In addition, the light receiving unit 9A has the transfer electrode 13 and the charge discharge electrode 17. In the light receiving unit 9A, a configuration immediately below the transfer electrodes 11 and 12 and the signal extraction electrodes 15 and 16 is the same as in Fig. 3, and a configuration immediately below the transfer electrode 13 and the charge discharge electrode 17 is the same as in Fig. 4. FIG. 17 is a cross-sectional view taken along line XVII-XVII of FIG. 16, including a configuration immediately below the transfer electrodes 51 and 52 and the signal extraction electrodes 55 and 56. As shown in FIG. 17, the light receiving unit has 9A further includes a charge collection area 9e (third charge collection area) and a charge collection area 9f (fourth charge collection area). The charge accumulation areas 9e and 9f are arranged adjacent to the photosensitive area 9a in the state of insertion of the photosensitive area 9a, collect charges from the photosensitive area 9a and store the charges in storage nodes, respectively. Incidentally, the configurations of the charge accumulation regions 9e and 9f are identical to those of the charge accumulation regions 9b and 9c shown in FIG. 3. The signal extraction electrode 55 is formed on the charge collecting area 9e and the signal extraction electrode 56 is formed on the charge collecting area 9f. The signal extraction electrodes 55 and 56 are in contact with the respective charge collecting regions 9e and 9f through openings formed in the insulation layer 41. The transfer electrode 51 is arranged on an area between the photosensitive area 9a and the charge collecting area 9e. The transfer electrode 52 is disposed on an area between the photosensitive area 9a and the charge collecting area 9f. When a positive potential (on potential) is applied to the transfer electrode 51, electrons fall from the photosensitive region 9a into a potential well of the charge collecting area 9e (charges are stored in the well). Similarly, when a positive potential (on potential) is applied to the transfer electrode 52, electrons fall from the photosensitive region 9a into a potential well of the charge collecting region 9f. A sensor drive circuit of the second modification drives the transfer electrodes 11, 12, 51 and 52 by sequentially executing a plurality of time-divided commands. 18 is a view illustrating a drive system of the sensor drive circuit according to the second modification. As shown in Fig. 18, an identical command F5 is repeated and the processing in command F5 is carried out in the drive system of the second modification. 18 also illustrates the processing contents within the F5 instruction. Within the command F5 there is alternately a storage command F6 for performing charge storage in storage nodes, each with the charge 15 CH 713 891 B1 collection areas 9b, 9c, 9e and 9f are coupled, and a read command F4 for performing charge readings from the charge collection areas 9b, 9c, 9e and 9f is repeated. Fig. 19 is a timing chart illustrating the operation of the transfer electrodes 11, 12, 13, 51 and 52 in the store command F6. 19 illustrates the drive clock CL, the drive voltage Vtx-i applied to the transfer electrode 11, the drive voltage Vtx 2 applied to the transfer electrode 12, a drive voltage Vtx 3 applied to the transfer electrode 51, a drive voltage Vtx 4 applied to the transfer electrode 52, and the driving voltage Vtxr applied to the transfer electrode 13. In the memory command F6, the drive voltages Vtx-i to Vtx 4 are repeatedly switched between the on potential and the off potential twice at a certain cycle T each time the drive clock CL rises. The cycle T is set to twice the on time t L of the drive clock CL (for example T = 2t L ). In addition, an on-time of the drive voltages Vtx-i to Vtx 2 in each cycle is half the on-time t L (ti_ / 2) of the drive clock CL. In particular, the uniform times t 0 , ti, ... and t 8 are defined in the store command F6 of each of the images F5, as shown in FIG. 19. An interval between these times is half the one-time irradiation time t L of the irradiation light L1. At this time, the light source unit 30 emits the irradiation light L1 for the times t-ι to t 3 . Then, in each of the commands F5, the sensor drive circuit 7 sets the drive voltage Vtx-i to the on potential between times t 0 and L and between times t 4 and t 5 , the drive voltage Vtx 2 to the on potential between times L. and t 2 and between times t 5 and t 6 , the driving voltage Vtx 3 to the on potential between times t 2 and t 3 and between times t 6 and t 7 and the driving voltage Vtx 4 to the on potential between the times t 3 and t 4 and between times t 7 and t 8 as in FIG. 19. Incidentally, the driving voltage Vtxr applied to the transfer electrode 13 is set to the on potential, except for a period in which the other driving voltages Vtx-i to Vtx 4 are first set to the on potential and then finally to the off. Potential can be set. This means that in each of the commands F5 the drive voltage Vtxr is set to the off potential between times t 0 and t 8 and to the on potential in the other periods. The second modification is an example in which the first instruction F1 and the second instruction F2 of the first modification are executed collectively in a single instruction F5. Accordingly, a distance calculation method after the second modification is the same as the distance calculation method after the first modification (see FIGS. 15A to 15C). That is, the output value of the first command F1 of the first modification can be set as a value in this second modification which is obtained by subtracting a charge amount of a storage node connected to a charge accumulation area 9b from a charge amount of a storage node connected to a charge accumulation area 9c and the output value of the second command F2 of the first modification can be set in this second modification as a value obtained by subtracting a charge amount of a storage node connected to a charge collection area 9e from a charge amount of a storage node connected to a charge collection area 9f. According to the second modification, it is possible to obtain a distance to an object B based on a difference between the amounts of charges stored in the storage nodes connected to the charge accumulation areas 9b and 9c and a difference between the amounts of charges, which are stored in storage nodes connected to the charge accumulation areas 9e and 9f, respectively, comparable to the above embodiment. Accordingly, it is possible to adapt the use method for injecting the same amount of charge into each storage node, and as a result, it is possible to avoid saturation of each of the storage nodes. In addition, it is also possible to achieve the other effects of the above-mentioned embodiment. [0097] In addition, the sensor driving circuit 7 can drive the transmission electrode 13 in each of the commands F5 as described above in the second modification. As a result, it is possible to further suppress saturation generated by stray light and reduce shot noise generated by stray light, and thus it is possible to improve resistance to the stray light and the accuracy of the distance measurement. The distance sensor and the driving method of the distance sensor according to the present invention are not limited to the above-described embodiments, and other further modifications can be made. For example, in the above embodiment, the example has been described in which each transistor of the sensor control circuit is a MOSFET, but each transistor may be another FET or a bipolar transistor. Reference symbol list [0099] 1A distance sensor Semiconductor substrate imaging area sensor drive CH 713 891 B1 8th processing circuit 9, 9A Light-receiving unit 9a photosensitive area 9b-9f Charge collection region 11, 12, 13, 51.52 transfer electrode 14 Photo gate electrode 15, 16, 55, 56 Signal extraction electrode 17 Ladungsentladeelektrode 20 Current injection circuit 21 Voltage generation circuit 25 power source 26a, 26b storage nodes 27, 28 buffer circuit 30 Light source unit 31 light source 32 light source drive 33 control circuit 34 Supply potential line 35, 36 Reset circuit 41 insulating B object CL Treibakt F1 first command F2 second command F3, F6 store instruction F4 read command F5 command GND Reference potential line L1 irradiation light L2 reflected light N1 node P pixel VtXi-Vtx 4 Drive voltage claims
权利要求:
Claims (8) [1] 1. A distance sensor (1A) configured to illuminate an object with light and measure a distance to the object by detecting reflected light from the object, the distance sensor comprising: CH 713 891 B1 a light irradiation unit (30) configured to repeatedly irradiate the object with the light in a pulsed state; a semiconductor substrate (5) having a photosensitive region (9a) which generates charges which correspond to an amount of light of the reflected light and first and second charge collecting regions (9b, 9c) which each detect the charges from the photosensitive region (9a), wherein the first and second charge collecting regions (9b, 9c) are arranged in a state of being separated from the photosensitive region (9a) by a predetermined distance; a first transfer electrode (11) disposed on an area between the photosensitive area (9a) and the first charge accumulation area (9b), the first transfer electrode (11) being adjustable to an on potential configured to transfer charge of enable the photosensitive area (9a) to the first charge accumulation area (9b) or an off potential configured to stop the charge transfer; a second transfer electrode (12) disposed on an area between the photosensitive area (9a) and the second charge accumulation area (9c), the second transfer electrode (12) being adjustable to a single potential configured to transfer charge from the photosensitive Enable area (9a) to the second charge accumulation area (9c) or an off potential configured to stop the charge transfer; and a drive unit (7) configured to sequentially execute a plurality of instructions, each of which forms an electrode drive pattern for driving the first and second transfer electrodes (11, 12) and by uniform time intervals of t 0 , L, ... and t 9 is defined to drive the first and second transmission electrodes (11, 12), the light irradiation unit (30) emitting the light for times ti to t 3 in each of the plurality of commands, the drive unit (7) in a first command (F1) sets the first transmission electrode (11) to the on potential between the times t 0 and t 2 and between the times t 4 and t 6 from the plurality of commands, while the second transmission electrode (12) to the on potential is set between times t 2 and t 4 and between times t 6 and t 8 , and the control unit (7) in a second command (F2) different from the first command, the first transmission electrode de (11) to the on potential between times L and t 3 and between times t 5 and t 7 , while the second transmission electrode (12) to the on potential between times t 3 and t 5 and between Times t 7 and t 9 is set. [2] 2. Distance sensor (1A) according to claim 1, wherein the control unit (7) in the first command (F1) from the plurality of commands, the first transmission electrode (11) to the on potential between times t 0 and L and between times t 4 and t 5 , while the second transmission electrode (12) is set to the on potential between times t 2 and t 3 and between times t 6 and t 7 , and the control unit in a second command different from the first command the first transmission electrode to the on potential between times ti and t 2 and between times t 5 and t 6 , while the second transmission electrode to the on potential between times t 3 and t 4 and between times t 7 and t 8 is set. [3] The distance sensor according to claim 2, wherein the semiconductor substrate (5) having the photosensitive region (9a) that generates charges corresponding to an amount of light of the reflected light further includes third and fourth charge collecting regions (9e-9f), each of which the charges detect from the photosensitive area (9a), the third and fourth charge collection areas (9e-9f) being arranged in a state of being separated from the photosensitive area (9a) by a predetermined distance; the distance sensor further comprises: a third transfer electrode (51) disposed on a region between the photosensitive region (9a) and the third charge collection region (9e), the third transfer electrode (51) being adjustable to an on potential configured to transfer a charge of enable the photosensitive area (9a) to the third charge collection area (9e) or an off potential configured to stop the charge transfer; a fourth transfer electrode (52) disposed on an area between the photosensitive area (9a) and the fourth charge accumulation area (9f), the fourth transfer electrode (52) being adjustable to an on potential configured to transfer charge of enable the photosensitive area (9a) to the fourth charge accumulation area (9f) or an off potential configured to stop the charge transfer; and the drive unit (7), which is configured to execute the plurality of commands in succession, for driving the first to fourth transmission electrodes (11, 12, 51, 52) and is defined by uniform time intervals fe, L, ... and t 8 to drive the first to fourth transfer electrodes (11, 12, 51, 52) and the drive unit (7) in each of the plurality of commands set the first transfer electrode (11) to the on potential between times L and t 2 and between the times t 4 and t 5 , the second transmission electrode (12) to the on potential between the times ti and t 2 and between the times t 5 and t 6 , the third transmission electrode CH 713 891 B1 (51) to the on potential between times t 2 and t 3 and between times t 6 and t 7 and the fourth transmission electrode (52) to the on potential between times tb and t 4 and between times t 7 and t 8 . [4] 4. Distance sensor according to one of claims 1 to 3, further comprising a fifth transmission electrode (13) which is arranged on a region between the light-sensitive region (9a) and a fifth charge collection region (9d), wherein the semiconductor substrate (5) further the fifth Has charge accumulation area (9d), which is arranged in a state in which it is separated by a predetermined distance from the photosensitive area (9a) and collects the charges from the photosensitive area (9a), and the drive unit (7) the fifth Set transmission electrode (13) to an on potential, with the exception of a period in which other transmission electrodes are first set to the on potential and then finally to the off potential. [5] 5. A driving method for a distance sensor configured to irradiate an object with light and measure a distance to the object by detecting reflected light from the object, the distance sensor (1A) comprising: a light irradiation unit (30) configured to repeatedly irradiate the object with the light in a pulsed state; a semiconductor substrate (5) having a photosensitive region (9a) which generates charges which correspond to an amount of light of the reflected light and first and second charge collecting regions (9b, 9c) which each detect the charges from the photosensitive region (9a), wherein the first and second charge collecting regions (9b, 9c) are arranged in a state of being separated from the photosensitive region (9a) by a predetermined distance; a first transfer electrode (11) disposed on an area between the photosensitive area (9a) and the first charge accumulation area (9b), the first transfer electrode (11) being adjustable to an on potential configured to transfer charge of enable the photosensitive area (9a) to the first charge accumulation area (9b) or an off potential configured to stop the charge transfer; and a second transfer electrode (12) disposed on a region between the photosensitive region (9a) and the second charge accumulation region (9c), the second transfer electrode (12) being adjustable to a single potential configured to transfer a charge of that to enable the photosensitive region (9a) to the second charge accumulation region (9c), or an off potential configured to stop the charge transfer, the driving method which executes a plurality of commands sequentially, each of which has an electrode driving pattern for driving of the first and second transmission electrodes and is defined by uniform time intervals t 0 , L, ... and t 9 , comprises: Emitting the light from the light irradiation unit (30) for times L to t 3 in each of the plurality of commands; Setting the first transmission electrode (11) to the on potential between times tb and t 2 and between times t 4 and t 6 , while the second transmission electrode (12) to the on potential between times t 2 and t 4 and is set between times t 6 and t 8 in a first command (F1) from the plurality of commands; and setting the first transmission electrode (11) to the on potential between times L and t 3 and between times t 5 and t 7 , while the second transmission electrode (12) to the on potential between times tb and t 5 and between the times t 7 and t 9 in a second command (F2), which differs from the first command, is set. [6] 6. control method according to claim 5, Setting the first transmission electrode (11) to the on potential between times tb and b and between times t 4 and t 5 , while the second transmission electrode (12) to the on potential between times t 2 and t 3 and between the times t 6 and t 7 are set in a first command (F1) from the plurality of commands; and setting the first transmission electrode (11) to the on potential between times b and t 2 and between times t 5 and t 6 , while the second transmission electrode (12) to the on potential between times tb and t 4 and is set between times t 7 and t 8 in a second command (F2) different from the first command. [7] The driving method according to claim 6, wherein the semiconductor substrate (5) includes a photosensitive area that generates charges corresponding to an amount of light of the reflected light, and further includes third to fourth charge collecting areas (9e, 9f), each of which charges from the photosensitive Detect area (9a), the third to fourth Charge collecting areas (9e, 9f) are arranged in a state of being separated from the photosensitive area (9a) by a predetermined distance; the distance sensor further comprises: a third transfer electrode (51) disposed on an area between the photosensitive area (9a) and the third charge accumulation area (9e), the third transfer electrode (51) being adjustable to an on potential configured to transfer charge of the photosensitive area (9a) to the third CH 713 891 B1 Allow charge accumulation area (9e) or an off potential configured to stop the charge transfer; and a fourth transfer electrode (52) disposed on an area between the photosensitive area (9a) and the fourth charge accumulation area (9f), the fourth transfer electrode (52) being adjustable to an on potential configured to transfer charge from the photosensitive area (9a) to the fourth charge accumulation area (9f), or an off potential configured to stop the charge transfer, the driving method that executes the plurality of commands sequentially to drive the first to fourth Transfer electrodes (11, 12, 51, 52) and defined by uniform time intervals tb, t-ι, ... and t 8 , comprises: setting the first transfer electrode (11) to the on potential between times tb and t- ι and between times t 4 and t 5 ; Setting the second transmission electrode (12) to the on potential between times h and t 2 and between times t 5 and t 6 ; Setting the third transmission electrode (51) to the on potential between times t 2 and t 3 and between times t 6 and t 7 ; and Setting the fourth transmission electrode (52) to the on potential between times t 3 and t 4 and between times t 7 and t 8 . [8] 8. The driving method according to one of claims 5 to 7, wherein the semiconductor substrate (5) further has a fifth charge collecting region (9d) which is arranged in a state in which it is separated from the photosensitive region (9a) by a predetermined distance, and collects the charges from the photosensitive area (9a), the distance sensor (1A) further comprises a fifth transfer electrode (13) disposed on an area between the photosensitive area (9a) and the fifth charge collection area (9d), and the fifth transfer electrode (13) is set to an on potential, with the exception of a period in which other transmission electrodes are first set to the on potential and then finally to the off potential.
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同族专利:
公开号 | 公开日 WO2017191758A1|2017-11-09| US20190145767A1|2019-05-16| DE112017002292T5|2019-01-17| JP6659448B2|2020-03-04| JP2017201245A|2017-11-09| CN109073734A|2018-12-21| KR20190002418A|2019-01-08| KR102289224B1|2021-08-13|
引用文献:
公开号 | 申请日 | 公开日 | 申请人 | 专利标题 JP5558999B2|2009-11-24|2014-07-23|浜松ホトニクス株式会社|Distance sensor and distance image sensor| JP5302244B2|2010-02-26|2013-10-02|浜松ホトニクス株式会社|Distance image sensor| JP5675468B2|2011-03-31|2015-02-25|本田技研工業株式会社|Ranging system| JP2013076645A|2011-09-30|2013-04-25|Stanley Electric Co Ltd|Distance image generation apparatus and distance image generation method| JP6010425B2|2012-10-26|2016-10-19|浜松ホトニクス株式会社|Distance sensor and distance image sensor| JP2014169921A|2013-03-04|2014-09-18|Denso Corp|Distance sensor| JP6386798B2|2014-06-09|2018-09-05|浜松ホトニクス株式会社|Ranging device| CN107924927A|2015-08-04|2018-04-17|松下知识产权经营株式会社|Solid camera head| JP6733100B2|2015-12-22|2020-07-29|株式会社リコー|Distance sensor, running body, robot and three-dimensional measuring device|CN110456370B|2019-07-30|2021-11-05|炬佑智能科技有限公司|Flight time sensing system and distance measuring method thereof|
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申请号 | 申请日 | 专利标题 JP2016092660A|JP6659448B2|2016-05-02|2016-05-02|Distance sensor and driving method of distance sensor| PCT/JP2017/015746|WO2017191758A1|2016-05-02|2017-04-19|Distance sensor, and method for driving distance sensor| 相关专利
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