• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
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    • 专利摘要:
    System and method for preventing vision impairment caused by prolonged use of electronic screens in low lighting conditions. The system includes a camera (215) directed towards a user, a processing circuit (214), a control circuit (211) and, optionally, a light sensor (216). The processing circuit (214) determines the illuminance of the user's face, and in the event that it falls outside a predefined range (putting the user at risk of deterioration of his vision in the future and the progression of myopia), The device stores the data of said illuminance or sends a control signal to notify the user. If the processing circuit (214) determines that the illuminance is equal to or greater than the predefined illuminance, the circuit may stop said notification. The notification may be modulated by any combination between such illuminance and the time of use. (Machine-translation by Google Translate, not legally binding)
    公开号:ES2724212A1
    申请号:ES201830203
    申请日:2018-03-02
    公开日:2019-09-09
    发明作者:Gil Norberto López；Mateusz Tomasz Jaskulski；Arthur Bradley
    申请人:Visionapp Solutions S L；
    IPC主号:
    专利说明:

    [0001] EXTENSION OF ELECTRONIC SCREENS IN LOW CONDITIONS
    [0002]
    [0003]
    [0004]
    [0005] Field of the Invention
    [0006] The present invention relates to the fields of visual optics, physiological optics, electronics and computers. In particular, the invention relates to systems and methods for preventing visual problems, such as myopia and eye fatigue, which are caused by prolonged use of electronic screens in low light conditions.
    [0007]
    [0008] Background of the invention
    [0009] Prolonged exposure to low light conditions is particularly dangerous when the person is engaged in near vision (for example, reading). Both situations are common in today's world where people spend many hours in closed places, watching their personal electronic screens very closely. Prolonged use of electronic displays (such as the screen of a smartphone, a tablet or a personal computer) in low light conditions causes visual problems, such as myopia and fatigue. These vision problems develop in children and young adults who, in comparison with previous generations, spend less time in environments with high levels of light (doing outdoor activities).
    [0010]
    [0011] Together with therapeutic methods to control the progression of myopia (drugs that paralyze accommodation, multi-focal contact lenses etc. [1]), it has been proven that spending time outdoors reduces the rate of myopia progression [2 ], and correlates with a lower prevalence of myopia in children [3], and high levels of light have been shown to prevent myopia in animal trials [4].
    [0012]
    [0013] The present invention represents a highly practical solution for the current and future society, where each child or adolescent has an electronic device, which prevent the progression of myopia and the deterioration of vision caused by its use in low light conditions.
    [0014]
    [0015] Bibliographic references
    [0016]
    [0017] [1] Huang, J., Wen, D., Wang, Q., McAlinden, C., Flitcroft, I., Chen, H., ... & Hu, L. (2016). Efficacy comparison of 16 interventions for myopia control in children: a network metaanalysis. Ophthalmology, 123 (4), 697-708.
    [0018]
    [0019] [2] Gwiazda, J., Deng, L., Manny, R., & Norton, T. T. (2014). Seasonal variations in the progression of myopia in children enrolled in the correction of myopia evaluation trial. Investigative ophthalmology & visual science, 55 (2), 752-758.
    [0020]
    [0021] [3] Wu, L. J., You, Q. S., Duan, J. L., Luo, Y. X., Liu, L. J., Li, X., ... & Jonas, J. B. (2015). Prevalence and associated factors of myopia in high-school students in Beijing. PLoS One, 10 (3), e0120764.
    [0022]
    [0023] [4] Smith, E. L., Hung, L. F., & Huang, J. (2012). Protective effects of high ambient lighting on the development of form-deprivation myopia in rhesus monkeys. Investigative ophthalmology & visual science, 53 (1), 421-428.
    [0024]
    [0025] Object of the invention
    [0026] The present invention relates to a system and a method for preventing vision impairment caused by spending long periods of time viewing the screen of an electronic device at close range and under low lighting conditions. The proposed solution makes use of the following components of the electronic device itself: a front camera and a processing circuit to process the information. A light sensor can also be included to perform a calibration. These hardware elements are present in most of the current portable electronic devices (smartphones and tablets).
    [0027]
    [0028] A system may include an electronic display controlled by a control circuit and coupled to a processing circuit. If the processing circuit determines that the illumination of the user's face is less than a threshold value defined by certain criteria, it can send a signal to the control circuit to alert the user or store the signal in memory for further processing by the user. user or a third person (the invention provides a mechanism for individuals to control their own levels of exposure to light or that of another person).
    [0029]
    [0030] The invention for controlling the progression of myopia described describes the levels of light to which the user is exposed by measuring the light reflected on his face while using the electronic device. In some embodiments, the device control circuit may notify the user when the processing circuit determines that a certain illumination value accumulated over time is below a certain criterion, for example, if a temporary average of the illumination of the User face is less than certain threshold value. If desired, the user can be notified by the device to increase the lighting in the room, move to a brighter area, or take a break. If the processing determines that said lighting is greater than or equal to a certain value, the control circuits may stop notifying or not initiate the notification.
    [0031]
    [0032] In some embodiments, the control circuit included in the device may modify the operation of the electronic display based on a relationship between the measured illumination and a predetermined value. For example, if the device is being used in low light conditions, and the processing circuit determines that the user's vision is at risk, the control circuits can notify the user, for example, by blurring, obscuring or changing Color the electronic screen. Like other examples of notification, the device could notify the user through information on the screen, emit a sound through the speaker, vibrate, or a combination of any of the above. The device could also store the information in memory for further processing by the user or by a third party.
    [0033]
    [0034] According to one of the aspects of the presented invention, a method is proposed to prevent the deterioration of vision caused by the prolonged use of electronic screens in low lighting conditions. The method comprises capturing, by means of the camera that includes the electronic device, an image that contains a user's face or at least a part of it, detecting, in the image, an area that contains at least a part of said face ; calculated the illuminance in said area of the image; determining whether the calculated illuminance meets at least one criterion; and generating a control signal based on the fulfillment of at least one criterion.
    [0035] The step in which it is determined whether the calculated illuminance meets at least one criterion may include having to find a relationship (eg, by comparison) between a predefined illuminance and the calculated illuminance; in such a way that the control signal is made based on said relationship.
    [0036]
    [0037] The method may also consist of a previous calibration process for the determination of a proportionality value k used in the calculation of the illuminance of the face.
    [0038]
    [0039] In one embodiment, the calibration process consists of: capturing, using the camera in the electronic device, an image containing a user's face or at least a part of it; the detection, in the image, of an area that contains at least a part of said face; an average of the gray level of the pixels within said area of the image; the measurement of the illuminance on the user's face using a light sensor included in the electronic device; and the determination of the proportionality value k using the measured illuminance and the average value of the gray level of the pixels.
    [0040]
    [0041] According to another embodiment, the calibration process includes: obtaining a skin type from the user's face; acquisition of a reflectance value associated with the skin type of a database; obtaining a camera calibration constant; and calculation of the proportionality value k using the reflectance value associated with said skin type and the camera calibration constant. The camera calibration constant can be obtained from a calibration database or, alternatively, it can be determined from camera parameters including certain parameters such as (may be more parameters): exposure time, ISO sensitivity, diaphragm aperture, or the physical size of the array of active pixels in the digital image sensor.
    [0042]
    [0043] In one embodiment, the control signal includes notifying the user of improper lighting. For example, such notification can be made, among others, in the following ways (or any combination of them):
    [0044] - Blurring at least a part of the electronic device screen. - Changing the color of at least part of the screen of the electronic device.
    [0045] - Changing the saturation of at least a part of the electronic device screen.
    [0046] - Changing the brightness of at least part of the screen of the electronic device.
    [0047] - Showing a message on the screen of the electronic device.
    [0048] - Generating a sound in a speaker of the electronic device.
    [0049] -Generating a vibration in a vibration component of the electronic device.
    [0050]
    [0051] Notification of inadequate lighting can be made when the calculated illuminance, as a discrete value or as an average value for a time, is outside a predefined range of illuminances. The notification of inadequate lighting can be modulated by a relationship between the calculated illuminance and the predefined illuminance.
    [0052]
    [0053] In another embodiment, the generated control signal may include the storage of the illuminance data calculated in an electronic device.
    [0054]
    [0055] In another embodiment, the illuminance can be calculated several times over a period of time, t and the control signal is generated using a calculation that combines the illuminance values and time; for example, the control signal can be generated depending on the time average of the illuminance and after a comparison with a predefined illuminance.
    [0056]
    [0057] According to another aspect of the invention, a system for the prevention of vision impairment caused by prolonged use of electronic screens in low lighting conditions is presented. The system consists of a camera, a processing circuit and a control circuit that, in combination, carry out the previously defined method. In particular, the camera is configured to capture an image of a user's face or at least part of it. The processing circuit is configured to detect an area that contains at least a part of said face in the image; determine if the calculated illuminance meets at least one criterion (for example, find or determine a relationship or a comparison between a predefined illuminance and the computed illuminance); and generate a control signal according to at least one of the defined criteria (for example, according to the relationship or comparison). The control circuit is configured to perform an action based on said control signal.
    [0058]
    [0059] The system may also consist of a light sensor to improve the accuracy of the face illuminance measurement, and where the processing circuit is further configured to perform the previously defined calibration process.
    [0060]
    [0061] According to one embodiment, the control circuit is configured to notify the user of inadequate lighting. The control circuit can be configured to modulate the notification of inadequate lighting based on a relationship between the calculated illuminance and the predefined illuminance.
    [0062]
    [0063] The system can also save the data related to the calculated illuminance; and a communication circuit configured to transmit the stored information to a network or other electronic device (for example a computer).
    [0064]
    [0065] The present invention also relates to an electronic device composed of the previously defined system. The electronic device may be, without limitation exclusively, one of the following: mobile phone, a tablet, a smart TV, a digital agenda (PDA), a laptop, a desktop computer, a separate camera, a video console, a video recorder or a smart watch.
    [0066]
    [0067] In accordance with another aspect of the present invention, a computer program with stored and readable instructions is proposed which, when executed by a processor of an electronic device, causes the processor to carry out the previously defined method.
    [0068]
    [0069] Brief description of the figures
    [0070] The following detailed descriptions of the figures serve to better illustrate the nature of the presented invention and its advantages:
    [0071]
    [0072] FIG. 1 is a block diagram of an illustrative electronic device for the prevention of vision impairment caused by low lighting conditions, according to an embodiment of the invention.
    [0073] FIG. 2 is a scheme of a system for the prevention of vision impairment according to an embodiment of the invention, where a camera is used to obtain an image of the user's face.
    [0074]
    [0075] FIG. 3 is an example of what a screen shows during the calibration process of an electronic device to prevent deterioration of sight according to an embodiment of the invention.
    [0076]
    [0077] FIG. 4 is a flow chart illustrating the calibration process of an electronic device to prevent sight deterioration according to an embodiment of the invention.
    [0078]
    [0079] FIG. 5 is a flow chart illustrating the process for the prevention of vision impairment according to an embodiment of the invention.
    [0080]
    [0081] FIG. 6 is an example of the application of the invention.
    [0082]
    [0083] FIG. 7 is a flow chart illustrating the calibration process according to another embodiment of the invention.
    [0084]
    [0085] Detailed description of the invention
    [0086] The present invention presents a system and method for preventing vision impairment caused by a prolonged period of time by looking at the screen of an electronic device in low light conditions. The electronic device can determine the illuminance of the face by a camera aimed at the user (front camera of an electronic device). If the measured illuminance is less than a certain value, which can put the user at risk of sight deterioration and the progression of myopia, the user can be notified, or the illuminance value can be stored in memory for further processing. by the user or by a third party. For example, an electronic device may include a camera coupled to a processing circuit for passive detection of the user's face. The processing circuit can analyze images from a camera (eg, single images or frames of a video) and determine if they contain an image of the face or at least a part of a user's face (hereinafter "user face" ). Next, images that contain an area of a user's face can be analyzed for determine a medium gray level of the pixels in the image of the user's face. The average gray level of the pixels in the sampled area is used to determine the average illuminance of that area based on a known relationship that includes the camera's F number, exposure time and the ISO sensitivity value of the camera sensor . General type equations like the one shown in (1) can be used to quantify this relationship.
    [0087]
    [0088]
    [0089]
    [0090]
    [0091] where E is the average illuminance of the sampled area of the face; And it is the average gray level of the pixels in the sampled area of the image. N is the number F, t is the exposure time, S is the ISO sensitivity, and k is a proportionality value.
    [0092]
    [0093] The proportionality value k in equation (1) depends on the reflectance of the user's face and the camera's calibration constant (for example, an increase applied by the control circuits of the electronic device) and is determined by a calibration initial.
    [0094]
    [0095] If the processing circuit determines that the illuminance (E) of the user's face is less than a threshold value (E 0 ) defined by a certain criterion, it can send a control signal to the control circuit to notify the user or store the signal in memory for further processing by the user or a third party. If the processing circuit determines that the value of said illuminance is equal to or greater than a certain value, the control circuit may stop notifying or not start it.
    [0096]
    [0097] In some embodiments, the device control circuit may notify the user when the processing circuit decides that a certain value of exposure to light accumulated over time meets a certain criterion, for example if the average illuminance (E) calculated over a certain time, t, exceeds a certain threshold value.
    [0098]
    [0099] In some embodiments the notification may be modulated by the time average of the illuminance (E), indicating that the illuminance of the face is too low or that It has harmful levels for eye health. For example, the screen may become progressively more blurred or darker.
    [0100]
    [0101] FIG. 1 schematically describes an electronic device for the prevention of vision impairment caused by prolonged stay in low lighting conditions according to an embodiment of the invention. The electronic device 100 may include a control circuit 101, storage 102, a communications circuit 103, an input interface 104, an electronic display or display 105, a light sensor 106, a camera 107 and a processing circuit 108. In some embodiments, one or more of the device components may be combined or absent. In some embodiments, the electronic device 100 may include other components that are not included in FIG. 1, such as a vibration module, a speaker, a microphone, an accelerometer, a gyro, or a combination thereof.
    [0102]
    [0103] The electronic device 100 can include any type of device with an electronic screen and a camera that allows to determine the illuminance of the user's face. In one embodiment, the electronic device 100 may also include a light sensor for use in a previous calibration process. For example, the electronic device 100 may include any of the following devices equipped with a camera and a light sensor: a mobile phone, a tablet, a smart TV, a digital agenda (PDA), a laptop or desktop computer, a camera, a video recorder or any other suitable device.
    [0104] The electronic device 100 is the configuration preferably, but it does not have to be limited to a portable device.
    [0105]
    [0106] The control circuit 101 may include any circuit and processor designed to control the functions, operations and operation of an electronic device 100. The storage 102 may include one or more storage means, such as internal or external memory of any kind, such as : HDD, SSD, RAM, ROM, EPROM, Flash EEPROM, flash memory card such as an SD card (eg, Secure Digital), or CF (i.e., Compact Flash), or any other type of memory suitable for the device electronic 100. The communication circuit 103 may include any circuit that can connect a device to a communications network and transmit communications using any suitable protocol such as, for example, Wi-Fi (for example, using the 802.11 protocol), Bluetooth®, mobile protocols
    [0107]
    [0108]
    [0109] (for example, GSM, GPRS, CDMA, EDGE, LTE), or any other communications protocol or any combination thereof. The input interface 104 may include any mechanism that can receive user inputs, such as a touch screen or a keyboard.
    [0110]
    [0111] Screen 105 may include some of the mechanisms for displaying information to a user. In some embodiments, the screen 105 may include a screen control circuit for brightness control. In addition, the screen 105 can be electronically coupled with the control circuit 101 or other components within an electronic device 100, or any combination thereof.
    [0112]
    [0113] The light sensor 106 may include one or more light sensors. For example, you can include two light sensors - one on each side of the device. As another example, it can include a wide or wide angle field light sensor. The camera 107 can be configured to measure the light at a narrow angle subtended by the user's face.
    [0114]
    [0115] The processing circuit 108 may include any type of data processing, such as a processor or a micro-controller. As described above, the processing circuit 108 may determine that the illuminance (E) of the face is less than a threshold defined by a certain criterion (E 0 ) and then send a control signal to the control circuit 101 for Notify the user or store the signal in memory 102 for further processing by the user or a third party
    [0116]
    [0117] FIG. 2 is a schematic view of the system of 200 for the prevention of vision impairment caused by low lighting conditions according to an embodiment of the invention, where a light sensor with a large field and a camera are used to measure the illuminance of the user face in a previously performed calibration process. The system 200 may include an electronic device 210, which may in turn include a light sensor 216, with a large angular field, a camera 215, and processing circuit 214 for detecting face 290 whose light has been diffusely reflected 291 and which it comes from ambient light 292. The electronic device 210 can be very similar to the electronic device 100 shown in FIG. 1 and share the descriptions of the latter components. For example, it can include an electronic device 210, a control circuit 211, a storage 212, a display 213 and a processing circuit 214, which can be substantially similar to the respective components of the electronic device 100; control circuit 101, storage 102, display 105 and processing circuit 108. The electronic device 210 may also include other suitable components such as a communication circuit 103 and an input interface 104 as shown in FIG. one.
    [0118]
    [0119] The processing circuit 214 may use any suitable technique or combination of techniques for image processing (eg, only images or video frames) of a camera 215, detect if they contain an image of the face of a user 290, and perform the calculation of the illuminance of the user's face using a formula, for example, Eq. 1. In addition, the processing circuit of 214 can determine if said illuminance of the face is less than a predefined value, setting the vision of the user at risk of deterioration due to low lighting conditions and progression of myopia; or if the illumination of the face for an average time meets a certain criteria.
    [0120]
    [0121] For example, if the illuminance of the user's face 290, determined by the processing circuit 214, does not meet a certain criterion, this circuit can send a signal to the control circuit 211. The control circuit 211 can perform an action accordingly with that signal. For example, the control circuit 211 may indicate to the screen 213 that it displays information to the user or modify its operation (ie, blur, darken or change the color of the screen). On the other hand, if the illuminance of the face 290, determined by the processing circuit 214, does not meet said criterion, or if the image of the face is not detected by the processing circuit 214, a control signal can be sent to the control circuit 211, which in turn can indicate to the screen 213 a modification of its operation. In some embodiments, said modification operation of the screen 213 may be replaced by a modification operation of another component of the device 200, such as: the vibration force of a component; the volume of sound emitted by a speaker; the local storage of the information related to the calculated and stored illuminance 212 for future processing or transmission of the information wirelessly or by means of a cable, using the communication circuit 103, or any combination of any of said modifications.
    [0122] In some embodiments, the modification intensity of the screen 213 can be modulated by the control circuit 211 in response to a control signal from the processing circuit 214. For example, a screen may become progressively more blurred, darker or brighter. as the ratio between the illuminance of the user's face and a predefined value becomes smaller.
    [0123]
    [0124] In some embodiments, the processing circuit 214 can perform processing and analysis of consecutive frames (ie, images in a video stream) to determine illuminance of the face several times over time, at a rate determined by the camera 215. In Some embodiments, control circuit 211, may modify frame rate or exposure to improve performance. For example, the processing and analysis speed performed by the processing circuit 214 can be modified by the control circuit 211 according to what the user has indicated and that has been previously provided by a similar input interface 104 in an electronic device 210 .
    [0125]
    [0126] In some embodiments, in order to increase the measurement accuracy of the illuminance of the face 290, the processing circuit 214 may take into account various parameters of the camera 215 and the image sensor, such as: the physical dimension of the sensor; the size of the camera image, the focal length of the camera lens; F number, sensitivity (ISO), or any combination of the above. In addition, for the same purpose, the processing circuit 214 can make use of additional capabilities of the chamber 215, such as autofocus control, exposure time or others, or any combination of the foregoing. For example, the processing circuit 214 may determine insufficient exposure of a face image 290 and send a control signal to the control circuit 211 to increase the exposure time of the camera 215.
    [0127]
    [0128] In some embodiments, a user can calibrate system 200 to prevent vision impairment caused by low lighting conditions. For example, the user may be able to find the proportionality value k in the formula of equation 1, using a light sensor 216.
    [0129]
    [0130]
    [0131] FIG. 3 is an illustrative example of a screen used in the calibration of an electronic device that prevents the deterioration of sight caused by low lighting conditions, according to an embodiment of the invention.
    [0132]
    [0133] The device 300 may be an electronic device with a screen, a light sensor with a large angular field and a camera. The device 300 may be similar to the device 100 shown in FIG. 1 and device 210 shown in FIG. 2, and share the descriptions of some or all of the components of the latter. For example, device 300 may include one or more light sensors 301 and one or more cameras 302 for capturing face images 290 (see light sensor 106 in FIG. 1, light sensor 216 in FIG. 2 , camera 107 in FIG: 1 and camera 215 in FIG.
    [0134] 2). The device 300 may include a screen 303 (see screen 105 in FIG. 1 and screen 213 in FIG. 2), in addition to any other component of the electronic device or any combination thereof.
    [0135]
    [0136] The electronic device 300 may display a screen calibration on screen 303 as part of the device calibration process, which may also include calibration aids. In the exemplary embodiment shown in FIG. 3, the calibration aid can include a real-time preview of face 305, a message with instructions 306, an area with a text 304, or any combination of the calibration aids.
    [0137]
    [0138] As described above, the user can calibrate the system to prevent vision impairment caused by low lighting conditions. For example, in some embodiments the proportionality factor k (EC. 1) can be set after including an illuminance value E c 304. The user can also calibrate the system after finding a relationship between the reference illuminance E c , measured with a light sensor 301 located near the user face, that is, with the light sensor 301 capturing the light upon reaching the user's face (eg, the back of the electronic device 300 is looking at the user's face), and the average gray level of the pixels in an image of the face captured by the camera 302 when the camera is placed at a certain distance in front of the user's face. The proportionality value k (EC. 1) can be calculated by the processing circuit 108 by the following equation:
    [0139] k = Ec'tc's2c (EC. 2) Yc-Nc2 V '
    [0140]
    [0141] where Y c , N c , t ac , and S e are, respectively, the average gray level of the pixels of the face image, the F number, the exposure time and the ISO sensitivity value, used during Calibration
    [0142]
    [0143] FIG. 4 shows the flow chart of a calibration process 400 of an electronic device to prevent sight deterioration caused by low lighting conditions according to the embodiment of the invention.
    [0144] The calibration process 400 can be performed by an electronic device (100; 210) with a screen (105; 213) and one or more light sensors (106; 216; 301) and one or more cameras (107; 215; 302 ).
    [0145]
    [0146] The calibration process 400 may consist of three steps. In the first step the camera is used to calculate illuminance reflected by the user's face (by analyzing the pixels of an image captured by the camera); In the second step, the light sensor is used to determine the illuminance on the user's face. The order in which the first and second steps are executed can be changed (that is, the second step can be performed before the first step). Finally, in the third step, the proportionality value k is calculated using the data captured in the first and second steps.
    [0147]
    [0148] This first step can begin with instruction 410, where an electronic device camera can be used to capture images of the user's face. Any suitable camera can be used to capture images 410 using the light reflected from the user's face (see 291 in FIG. 2). In instruction 420, a user can be instructed to keep an electronic device at a certain distance and keep an image of its head aligned (e.g. see calibration aid 304 in FIG. 3). For example, a user may be warned in instruction 420 by means of an instruction message (eg, see instruction message 306 in FIG. 3) to keep the electronic device directed towards itself and at a calibration distance of, for example , 40 cm
    [0149]
    [0150]
    [0151] In instruction 430, the user's face or a part of it can be detected in an image captured by the camera. As described above, any suitable technique or combination of techniques for image processing (i.e., only images or video frames) of one or more cameras, can be used by the processing circuit (108; 214) to detect At least one image of the user's face. Instruction 440 can serve as a decision node in process 400. For example, if the user's face is detected in instruction 430, process 400 can continue with instruction 440. In instruction 450 the average gray level of the Y pixels in the image of the user's face is determined by the processing circuit and stored in memory (see, for example, information storage 102 in FIG. 1 and storage 212 in FIG. 2).
    [0152]
    [0153] In instruction 460, which marks the start of the second stage of the calibration process 400, the user is instructed to place the light sensor (106; 216) of the electronic device at face level, in the vicinity thereof. For example, within an embodiment of the invention, the user may indicate in instruction 460, by means of an instruction message (see, for example, usage message 306 in FIG. 3) to rotate the electronic device that is located level of the face and close to it, and directed it outward, where the light reaches it while remaining in the same position and with the same illuminance. In instruction 470 the light sensor is used to measure the illuminance E c that reaches the user's face.
    [0154]
    [0155] In instruction 480 of the third step, the processing circuit calculates the proportionality value k of equation 2 from the illuminance E c , measured in the second step with the light sensor 216 and the illuminance calculated in the first step and It is stored in the memory of the electronic device.
    [0156]
    [0157] As described above, an electronic system for the prevention of vision impairment caused by prolonged periods of time in low light conditions may notify the user when the processing circuit determines that the illuminance of the user's face is less than a threshold. defined by a certain criterion.
    [0158]
    [0159] FIG. 5 shows a flow chart of process 500 for preventing vision impairment caused by large amounts of time under low conditions
    [0160]
    [0161]
    [0162] lighting according to an embodiment of the invention. The process 500 can be performed by an electronic device (corresponding to the device 100 in FIG. 1 or the device 210 in FIG. 2) with a screen (see, for example, electronic screen 105 in FIG. 1 and the screen of 213 in FIG. 2) and a camera (see for example 107 in FIG. 1 and 215 in FIG. 2) and may include a wide angle light sensor (see, for example, a light sensor 106 in FIG. 1 and light sensor 216 in FIG. 2). In some embodiments, the process 500 may be performed in the background of the electronic device running in a continuous loop.
    [0163]
    [0164] The process 500 can begin with instruction 510. In it, a camera (see 215 FIG. 2) can be used to capture images of the user's face. Any suitable camera can be used to capture images in instruction 510, using light reflected from the user's face (see 291 in FIG. 2). In instruction 520, the user's face or a part thereof can be detected in an image of the camera by the processing circuit (see processing circuit 107 in FIG. 1 and 214 in FIG. 2). Instruction 530 can serve as a first decision node in process 500. For example, if the user's face or part of it is detected in instruction 520, process 500 can continue with instruction 540. On the other hand, if The user's face or part of it is not detected, process 500 can return to instruction 510.
    [0165]
    [0166] In instruction 540 the illuminance of the user's face can be calculated by the processing circuit from an image captured by the camera. As described above, any appropriate technique or combination of techniques for image processing (i.e., only images or video frames) can be used by the processing circuit to detect if they contain an image of the user's face and to Calculate the illuminance of the user's face with the EC. one.
    [0167]
    [0168] Instruction 550 can serve as a second decision node in process 500. For example, if the illuminance E of a user's face is less than a predefined value Eo, (E <Eo), in instruction 560 the circuit of The processing can send a control signal so that the control circuit (see, for example, control circuit 101 in FIG. 1 and 211 in FIG. 2) notifies the user or stores in memory the data related to the measured illuminance in the user's face. On the other hand, if the illuminance of the user's face is greater than or equal to said predefined value (E> Eo), the The processing circuit can send a control signal to the control circuit to stop notifying the user in instruction 570.
    [0169]
    [0170] The process described above, 500 can be performed as a background process of a device in a continuous loop. In this case, after finishing instruction 560 or 570, process 500 may return to instruction 510.
    [0171]
    [0172] As described above, the processing circuit (see circuit 107 in FIG. 1 and the precessing circuit 214 in FIG. 2) of the electronic device can make use of additional capabilities of a camera, such as autofocus control, exposure or others, or any combination of any of the foregoing in order to improve the detection performance of the user's face in an image of a camera in instruction 520 of the 500 process. For example, any processing circuit suitable can determine insufficient exposure of an image of the user's face and send a control signal to the circuit control (see circuit control 101 in FIG. 1 and 211 in FIG. 2) to increase the exposure time of the camera (see camera 215 in FIG. 2).
    [0173]
    [0174] FIG. 6 shows an example of the application of the invention in measuring the illuminance of the faces of three users. In particular, FIG. 6. describes an example of illuminance measurements obtained in process 500 in a group of three subjects of three different ethnicities: Caucasian (solid), Asian (dotted) and African (discontinuous), characterized by different values of skin reflectance.
    [0175]
    [0176] Under the same lighting conditions, the average gray level of the Y pixels obtained in the Caucasian user was 1.15 times higher than the Asian and 2.8 times higher than the African subject, due to differences in reflectance of their skins The value of proportionality, k in the EC. 2, corrects the value of the illuminance for said skin difference, which allows a more precise measurement of the illuminance of the user's face regardless of the skin's reflectance value.
    [0177]
    [0178] As described above, the proportionality value k depends on the reflectance of the user's face and a camera calibration constant, which in turn depends on the gain applied by the electronic device control circuit. Given that the differences between reflectance of the different
    [0179]
    [0180]
    [0181] Skin types can be estimated roughly (Caucasian, Asian, African), as shown in FIG. 6, the calibration process 400 that determines the proportionality value k can be performed in a simplified manner (without the use of a light sensor), by manually entering the calibration screen, by the user, of your skin type . Since the camera calibration constant can be calculated from known camera parameters and the gain applied by the electronic device control circuit, the proportionality value k can be calculated from the skin type.
    [0182]
    [0183] FIG. 7 shows a simplified flow chart of the calibration process 700 of an electronic device to prevent sight impairment caused by low lighting conditions in accordance with an embodiment of the invention.
    [0184]
    [0185] The 700 calibration process can be performed with an electronic device (100; 210), with a screen (105; 213) and with one or more cameras (107; 215; 302).
    [0186]
    [0187] The process 700 can be started with instruction 702, where the user will be asked to manually include the type of skin he has. For example, the user can select the skin type from a list of options, including, but not limited to, the skin type associated with a race (Caucasian, Asian, African, etc.), or skin tone ( dark black, soft black, white, etc.). The process can then access a skin reflectance database 722 in instruction 706 and retrieve a reflectance value associated with the selected skin type 704. Subsequently, in instruction 708, the camera calibration constant is obtained of a 724 calibration database. The database can be included in the storage memory of the electronic device 102, 212, 720 or, alternatively, it can be located on a remote control server that is accessed wirelessly or by a cable using the electronic device. Finally, with instruction 710 the proportionality value k can be estimated. Although more imprecise, this calibration process avoids the need for a light sensor and simplifies the calibration process shown in FIG.
    [0188] Four.
    [0189]
    [0190]
    one
    权利要求:
    Claims (20)
    [1]
    1. A method to prevent vision impairment caused by prolonged use of electronic screens in low lighting conditions, the method comprising:
    the capture (510), using a camera (215) included in an electronic device (210), of an image containing the face (290) of a user or at least a part thereof;
    the detection (520), in the image, of an area containing at least a part of said face (290);
    the calculation of the illuminance (540) in said area of the image;
    the determination (550) of whether the calculated illuminance (540) meets at least one criterion; Y
    the generation of a control signal (560, 570) according to the fulfillment of the at least one criterion.
    [2]
    2. The method of claim 1, wherein the step of determining (550), if the calculated illuminance (540) meets at least one criterion consisting in finding a relationship between a predefined illuminance and the calculated illuminance; and in which the generated control signal (560, 570) is performed according to said relationship.
    [3]
    3. The method of claim 1, further comprising a calibration process (400, 700) to determine a proportionality value k used in the calculation of face illuminance (540).
    [4]
    4. The method of claim 3, wherein the calibration process (400) comprises:
    the capture (410), using the camera (215) included in the electronic device (210), of an image containing the face (290) of a user or at least a part thereof;
    the detection (430) in the image of an area containing at least a part of said face (290);
    the calculation (450) of the average gray level of the pixels (Yc) within said area of the image;
    the measurement (470) of the illuminance (E c ) of the user's face (290) using a light sensor (216) included in the electronic device (210); Y
    2
    the determination (480) of the proportionality value k using the measured illuminance (E c ) and the calculated average value of the gray level of the pixels (Yc).
    [5]
    5. The method of claim 3, wherein the calibration process (700) comprises:
    obtaining (704) the skin type of the face (290) from the user;
    obtaining (706) the reflectance value associated with said skin type from access to a skin reflectance database (722),
    obtaining a camera calibration constant (215); Y
    the determination (710) of the value of proportionality k from the reflectance associated with said skin type and the calibration constant of the chamber (215).
    [6]
    6. The method of claim 5, wherein the chamber calibration constant (215) is obtained (708) from a calibration constant database (724).
    [7]
    7. The method of claim 5, wherein the camera calibration constant (215) is determined from camera parameters, including but not limited to: exposure time, ISO sensitivity value, size of the lens diaphragm, the physical size of the matrix of active pixels in the digital image sensor.
    [8]
    8. The method of any of claims 1 to 7, wherein the generation of the control signal includes notification to users (560) of inadequate lighting.
    [9]
    9. The method of claim 8, wherein notification to the user of improper lighting includes any of the following possibilities:
    blurring at least a part of a screen (213) of the electronic device (210);
    the color change of at least a part of the screen (213) of the electronic device (210);
    the saturation change of at least a part of the screen (213) of the electronic device (210);
    the brightness change of at least a part of the screen (213) of the electronic device (210);
    the presentation of a message on the screen (213) of the electronic device the generation of a sound in a speaker of the electronic device (210);
    the generation of a vibration in a component of the electronic device (210); or
    Any combination of these.
    [10]
    10. The method of any of claims 8 to 9, wherein notification to the user (560) of improper lighting is performed when the illuminance, calculated as a discrete value or as a temporary average, is outside a predefined range. of illuminances.
    [11]
    11. The method of claims 8 to 9, wherein the notification to the user of insufficient lighting is modulated based on the relationship between the calculated illuminance and the predefined illuminance.
    [12]
    12. The method of any one of claims 1 to 11, wherein the generation of the control signal includes storing the illuminance data calculated in the memory (212) of the electronic device (210).
    [13]
    13. The method of any one of claims 1 to 12, wherein the illuminance is continuously calculated for a certain time, t, and the control signal is generated (560, 570) based on a formula that takes into account the Illuminance data collected over time.
    [14]
    14. A system for the prevention of vision impairment caused by prolonged use of electronic screens in low lighting conditions, the system comprising:
    - a camera (215) configured to capture an image containing the face (290) of a user or at least a part of it;
    - a processing circuit (214) configured to:
    detecting in the image an area that contains at least a part of said face (290);
    calculate an illuminance in that area;
    determine if the calculated illuminance (540) meets at least one criterion;
    generate a control signal if at least one of the established criteria is met; Y
    - a control circuit (211) configured to perform an action based on said signal.
    [15]
    15. A system according to claim 14, further containing a light sensor (216) and wherein the processing circuit (214) is configured to carry out a calibration process (400) according to claim 4.
    [16]
    16. The system according to any of claims 14 to 15, wherein the control circuit (211) is configured to notify the user (560) of improper lighting.
    [17]
    17. The system according to claim 16, wherein the control circuit (211) is configured to modulate the notification of inadequate lighting based on a relationship between the calculated illuminance and the predefined illuminance.
    [18]
    18. The system according to any of claims 14 to 17, which further includes:
    -a storage (102) configured to store data related to the calculated illuminance; Y
    -a communication circuit (103) configured to transmit stored information on a network.
    [19]
    19. An electronic device (100, 210, 300) comprising a system according to any of claims 14 to 18, wherein the electronic device is one of the following:
    - a Mobile phone;
    - a tablet;
    - a smart TV;
    - a digital agenda (PDA);
    - a laptop;
    - a desktop computer;
    - an independent camera;
    - a video game console;
    2
    - a video recorder; or
    - a smart watch.
    [20]
    20. A computer program that includes instructions for the computer stored in memory and that when executed by a processor of an electronic device (100,200,300), causes the processor to carry out the method of claims 1 to 13.
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    同族专利:
    公开号 | 公开日
    PT3759444T|2021-12-02|
    EP3759444A1|2021-01-06|
    EP3759444B1|2021-08-25|
    CN112088293A|2020-12-15|
    US11257201B2|2022-02-22|
    US20210012479A1|2021-01-14|
    ES2724212B2|2021-03-31|
    WO2019166238A1|2019-09-06|
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    ES201830203A|ES2724212B2|2018-03-02|2018-03-02|METHOD IMPLEMENTED IN THE COMPUTER AND SYSTEM FOR THE PREVENTION OF VISION IMPAIRMENT CAUSED BY THE PROLONGED USE OF ELECTRONIC DISPLAYS IN LOW LIGHTING CONDITIONS.|ES201830203A| ES2724212B2|2018-03-02|2018-03-02|METHOD IMPLEMENTED IN THE COMPUTER AND SYSTEM FOR THE PREVENTION OF VISION IMPAIRMENT CAUSED BY THE PROLONGED USE OF ELECTRONIC DISPLAYS IN LOW LIGHTING CONDITIONS.|
    US16/977,574| US11257201B2|2018-03-02|2019-02-15|Computer-implemented method and system for preventing sight deterioration caused by prolonged use of electronic visual displays in low-light conditions|
    PCT/EP2019/053792| WO2019166238A1|2018-03-02|2019-02-15|A computer-implemented method and system for preventing sight deterioration caused by prolonged use of electronic visual displays in low-light conditions|
    EP19705509.8A| EP3759444B1|2018-03-02|2019-02-15|A computer-implemented method and system for preventing sight deterioration caused by prolonged use of electronic visual displays in low-light conditions|
    CN201980029836.5A| CN112088293A|2018-03-02|2019-02-15|Computer-implemented method and system for preventing visual deterioration caused by long-term use of electronic visual display under dim light condition|
    PT197055098T| PT3759444T|2018-03-02|2019-02-15|A computer-implemented method and system for preventing sight deterioration caused by prolonged use of electronic visual displays in low-light conditions|
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