• 专利附录
  • 专利说明
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    • 专利摘要:
    The present invention discloses a keypad (5) comprising - a plate (2) which comprises push buttons (1) at given positions and is adapted to propagate a force or displacement exerted on the plate in a surface of the plate by operating a push button, sensor elements (51) arranged at given positions on a rigid surface (4) and adapted to convert the force or displacement into corresponding electrical signals, the sensor elements being coupled to each other via that plate, - analysis means (21) adapted to receive the electrical signals and to determine whether an error occurs in the keypad when the push button is operated, based on analysis of the received electrical signals, so as to take into account positioning information of the one or more push buttons and of the sensor elements on the rigid surface.
    公开号:BE1022330A9
    申请号:E20145003
    申请日:2014-10-01
    公开日:2017-01-27
    发明作者:Bart Vercoutter；Bram Baert；Carl Eeckhout
    申请人:Televic Rail；
    IPC主号:
    专利说明:

    Field of the Invention The present invention relates generally to the field of push buttons and keyboards comprising such push buttons for activating or deactivating a particular function. The invention also relates to methods for automatically testing such push buttons.
    Background of the Invention A variety of applications require verification of the correct operation of push buttons and keypads or keyboards that include a plurality of such push buttons that are handled by humans, devices, animals, etc. Typically this is done by manually verifying the installed keys of interest. This is often a time-consuming task that does not provide guaranteed coverage. Given the required effort, testing is usually limited to a minimum, leaving the possibility of sleeping errors behind.
    Push buttons provided on the keypad are used to trigger a system, which system is adapted to perform one or more functions associated with these push buttons. Examples include playing a jingle at the start of an announcement to be made in a transport vehicle or displaying a message on a screen. Observing the trigger signal can activate or deactivate a function in a system. These functions can be safety critical. Therefore, a high reliability of the push button is required. To ensure correct operation of the push button, regular testing, possibly even continuous, is necessary without adversely affecting the operation of the push button.
    Conventional push buttons are often designed as a moving element, which converts a mechanical force exerted on the key into a movement that brings an electric, pneumatic, hydraulic, ... switching element into an alternating bistable state. An external force is required to test the switching behavior. The reliability of the switching function is highly dependent on the mechanical reliability of the switching element, since this is considered as a single point of failure that causes reliability limitations in error tree analysis exercises. The only way to resolve this issue is to provide a second mechanical structure that increases dimensions of key in size, cost, and complexity.
    Another drawback of current push-button technology is that the push-buttons are often difficult to find for blind or visually impaired people. By adding an audible signal and sense of touch, a push button could be found more easily.
    Various test systems for push buttons have been described in the art. Application KR20100077248 discloses a test system for a key switch of a sound generator for a visually impaired person. This permits a suitable test via one-time input setup by providing a drive unit that holds a key switch, whereby a end of an operating rod repeats pressing and releasing a push button. A counter detects a voltage while the push button is pressed and counts the times of detected voltage. A controller compares the accumulated count number with a set count number and stops the operation of a hydraulic cylinder in the event of a match.
    GB 2442246 presents a light-controlled pedestrian crossing with a touch indicator. A touch signal module is provided which comprises an electric DC motor which drives a rotating touch indicator.
    Patent EP 08711185 discloses a push button, which provides a tact mark and an audible mark. US 4851836 also relates to a sound / push button press signal signaling system for pedestrians.
    However, in many applications, push buttons occur in keypads or keyboards that comprise a plurality of push buttons. A very well-known example is a telephone keypad, as described in e.g. US2001 / 003539.
    There is therefore a need for a solution in which the problems encountered in the known solutions have been overcome.
    Summary of the Invention It is an object of embodiments of the present invention to provide a keypad that is capable of detecting an error in its operation. It is a further object to provide a keypad that enables error-tolerant detection of the activated key. Another purpose is to provide a keypad that can perform autonomous test operation.
    The above object is achieved by the solution according to the present invention.
    In a first aspect, the invention relates to a keypad comprising - a plate comprising a plurality of push buttons at given positions, the plate being adapted to propagate a force or displacement in a surface of the plate, which is exerted on the plate by operating one of the push buttons, - a plurality of sensor elements, which are arranged at given positions on a rigid surface and are adapted to convert the force or displacement into corresponding electrical signals, the sensor elements of the plurality of sensor elements are electrically insulated from each other and mechanically coupled to each other via the plate, - connecting means for connecting the plate to the rigid surface, the connecting means providing resistance to movement of the plate relative to the rigid surface, - analyzing means said detection means comprising a prim on the electrical signals perform aary detection corresponding to the sensor signal with the largest amplitude detected by the nearest sensor element when one of the push buttons is activated and to perform a secondary detection corresponding to sensor signals with a smaller amplitude detected by sensor elements further away from the activated push button, wherein the distance between the given positions of the push buttons and the given positions of the sensor elements is exploited, the analysis means further adapted to determine which push button is activated using redundant information from the first and second detection.
    The claimed keypad indeed does achieve the goal of enabling detection of an error in the keypad when one or more of the push buttons are operated. The proposed solution therefore paves the way for error-tolerant detection. Due to the presence of a plurality of sensor elements coupled to each other via the plate comprising the push buttons, ripple detection can be applied, ie, different sensor elements take a degree, depending on their distance from the pressed key, a force or displacement where applied to one of the push buttons. There is clearly a relationship between the applied amount of force or displacement and the observation signal level depending on the distance from a certain position on the plate to the activated push button, this is called "ripple". The various ripple sensing signals allow for secondary detection which can be utilized together with the primary sensing (i.e., the sensing signal closest to the affected push button, which produces the highest amplitude value). The primary and secondary detection make it possible to detect an error in the operation of the keypad and mitigate the effect of that possible error. They also make it possible to determine which push button is operated. In one embodiment, the number of sensor elements is equal to the number of push buttons, so that one sensor element is provided for each push button, the sensor element being substantially located under the corresponding push button. In another embodiment, the sensor elements are scattered without a one-to-one relationship with the push buttons.
    The proposed structure is also advantageously suitable for performing an automatic test of the keypad. In a preferred embodiment, the keypad comprises a generator means, which is adapted to generate test signals to be applied to at least one of the sensor elements. This feature makes implementation of the automatic test function possible. By sending test signals with predefined characteristics and analyzing the response signals from the sensor elements, the correct functioning of the keypad can be tested. In one embodiment the generator means can be directly connected to the sensor means, while in another embodiment an indirect connection can be effected via the plate.
    In a favorable embodiment, the keypad comprises a control which is arranged for controlling the generator means and for defining parameters for the test signal. The control contains the "intelligence" to determine the test scenarios.
    In a preferred embodiment, the analyzing means comprises logic circuits for performing the analysis of the received electrical signals.
    The sensor elements are preferably piezoelectric sensors or capacitive sensor elements.
    Advantageously, the test signal has a frequency in the audible frequency range. In another embodiment, the generator means provides haptic feedback for the keypad.
    In a preferred embodiment the keypad comprises a stack formed by one of the sensor elements and one of the generator means. Alternatively, the stack is formed by a plurality of sensor elements. In another embodiment, the stack comprises more than one sensor element and more than one generator means. Typically, the keypad comprises a plurality of such stacks.
    Advantageously, a coupling between the sensor element and the generator means is provided. In one embodiment, the sensor element and the generator means are integrated.
    In a specific embodiment, the keypad comprises a spacer to separate the plate and the rigid surface from each other.
    In another aspect, the invention relates to a method for testing a keypad that includes a plate that includes one or more push buttons at given positions, the plate being adapted to propagate in a surface of the plate of a force or displacement exerted on the plate by actuating one of the push buttons, and a plurality of sensor elements disposed at given positions on a rigid surface and adapted to convert the force or displacement into corresponding electrical signals, wherein the sensor elements are coupled to each other via the plate, the method comprising - operating push buttons of the keypad, - receiving electrical signals from the plurality of sensor elements in response, - determining whether an error occurs in the keypad based on analysis of the electrical signals received, so as to take into account information about the po positioning of the one or more push buttons and of the plurality of sensor elements on the rigid surface.
    Preferably, the method comprises a step of generating a test signal and applying the test signal to the plurality of sensor elements.
    In another aspect, the invention relates to a method for determining which push button is operated on a keypad, wherein the keypad comprises a plate comprising a plurality of push buttons at given positions, the plate being adapted to propagating a surface of the plate from a force or displacement exerted on the plate by actuating one of the push buttons, and comprising a plurality of sensor elements disposed on a rigid surface at given positions and adapted to convert of the force or displacement in corresponding electrical signals, the sensor elements being electrically isolated from each other and mechanically coupled to each other via the plate. The method comprises - receiving the electrical signals from the plurality of sensor elements, - performing on the electrical signals a primary detection corresponding to the sensor signal with the greatest amplitude detected by the nearest sensor element when one of the push buttons is activated - performing a secondary detection corresponding to sensor signals with a smaller amplitude detected by sensor elements further away from the activated push button, wherein the distance between the given positions of the push buttons and the given positions of the sensor elements is exploited, - determining which push button the keypad is operated using redundant information from the first and second detection.
    The proposed solution makes it possible to operate the keypad correctly, if one of the sensor elements is out of operation, even when it concerns the operated key.
    For the purpose of summarizing the invention and the advantages obtained over the prior art, certain objects and advantages of the invention have been described above. It will, of course, be understood that not all of the objectives or advantages can be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention can be embodied or embodied in a manner that achieves or optimizes one advantage or group of advantages as mentioned herein, without necessarily having other purposes or advantages, as they may be mentioned or suggested herein. , reach.
    The above and other aspects of the invention will become apparent from and further explained with reference to the embodiment (s) described below.
    Brief description of the drawings The invention will now be further described by way of example with reference to the accompanying drawings, in which the same reference numerals refer to the same elements in the various figures.
    Fig. 1 shows a part of one embodiment of the keypad of the invention.
    Figure 2 shows the effect of wrinkle perception.
    Fig. 3 shows ripple detection with piezo sensor elements.
    Fig. 4 shows a detection scheme for the analyzer.
    Fig. 5 shows the logic circuits in the analyzer for performing the analysis of the various received signals.
    Fig. 6 shows an embodiment of the keypad Imet generator means and a controller.
    Fig. 7 shows some possibilities for a key stack.
    Fig. 8 represents an embodiment in which the generator is provided with auditory, haptic and automatic test means.
    FIG. 9 shows a push button which implements displacement for controlling the button.
    Fig. 10 represents an embodiment of a keypad with capacitive sensing.
    Fig. 11 shows a waveform diagram of detection via specific test planning.
    Fig. 12 shows a redundant stacking with piezoelectric elements.
    Fig. 13 shows two stacks with piezoelectric generator sensor elements.
    Fig. 14 shows a distinct stacking of piezoelectric and capacitive sensing elements.
    Detailed Description of Illustrative Embodiments The present invention will be described with reference to particular embodiments and with reference to certain drawings, but the invention is thereby not limited, but only by the claims.
    Furthermore, the terms first, second and the like in the description and in the claims are used to distinguish between equal elements and not necessarily to describe a sequence in time, space, arrangement or in any other way. It will be appreciated that the terms thus used are interchangeable under proper conditions and that the embodiments of the invention described herein may operate in sequences other than those described or shown herein.
    It is to be noted that the term "comprising" used in the claims is not to be construed as limiting the agents listed thereafter; this term does not exclude other elements or steps. This term is therefore to be understood as the presence of the stated characteristics, integers, steps or components, as indicated, specifying, but does not exclude the presence or addition of one or more other characteristics, integers, steps or components or groups thereof from. The scope of the expression "a device comprising means A and B" should therefore not be limited to devices that consist only of components A and B. With regard to the present invention, this means that A and B are the only relevant components of the device.
    Reference to "one embodiment" or "an embodiment" throughout the specification means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. The phrase "in one embodiment" or "in an embodiment", which occurs at different places in this description, thus do not necessarily all refer to the same embodiment, but they can. Furthermore, the particular features, structures or characteristics can be suitably combined in one or more embodiments, as will be apparent to those skilled in the art.
    Accordingly, it will be appreciated that in the description of examples of embodiments of the invention, various features of the invention are sometimes grouped in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and assisting in understanding one or more of the various aspects of the invention. However, this method of disclosure should not be construed as an intention that the claimed invention requires more features than are explicitly stated in each claim. In contrast, as the following claims reflect, inventive aspects lie in less than all the features of a single preceding disclosed embodiment. Thus, the claims following the detailed description are hereby expressly included in the detailed description, each claim per se standing as a separate embodiment of the present invention.
    Furthermore, although some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are intended to be within the scope of the invention and to form different embodiments, as will be apparent. are for the skilled person. For example, in the following claims, any of the claimed embodiments can be used in a combination.
    It should be noted that the use of particular terminology in describing certain features or aspects of the invention should not be taken to imply that the terminology is redefined herein to be limited to including specific characteristics of the features or aspects of the invention with which this terminology is associated.
    Numerous specific details are set forth in the description provided herein. It will be understood, however, that embodiments of the invention may be practiced without these specific details. In other cases, well-known methods, structures, and techniques are shown in detail so as not to interfere with the understanding of this description.
    The proposed solution utilizes the use of ripple detection to detect a plurality of signals caused by the operation of one of the push buttons. As will be described in detail below, this produces various beneficial effects. In one aspect, the present invention discloses a keypad that makes it possible to determine the correct operation of the keypad when one or more push buttons are operated. In another aspect, the present invention relates to a keypad that makes an error-tolerant decision of which push button is pressed from the variety of push buttons provided in a plate on the surface of the keyboard.
    Fig. 1 shows an embodiment of the keypad (5) according to the invention. The push buttons (1) are arranged in a plate (2) where they are arranged at defined positions. The keypad comprises a plurality of sensor elements (51) positioned at defined locations on a rigid surface (4). An option may be that one sensor element is provided for each push button. The sensor element is then preferably located under the corresponding push button. Alternatively, the sensor elements are positioned such that they are arranged scattered throughout the plate, without a one-to-one positioning between a push button and a sensor element. The sensor elements are connected to each other via the plate which comprises the push buttons.
    When a push button is operated, a force or displacement is applied to that button. This force or displacement propagates in the surface of the plate, which comprises the plurality of push buttons. The sensors are connected to each other via that plate. Several of the sensors therefore perceive the effect of the force or displacement to a greater or lesser extent. This is called ripple effect. The sensors convert the perceived force or displacement into a number of electrical signals (e.g., one for each sensor). These signals are supplied to an analyzer block, which comprises processing means, which are capable of determining whether the operated push button functions without error and are able to decide which push button is operated. This entails an analysis of the amplitude of the various received signals and the known positions of the push buttons and the sensors.
    Fig. 1 shows a preferred embodiment of a keypad according to the invention. The parallel mounting of more sensor elements is shown. The sensor elements are electrically insulated from each other, but mechanically connected to each other in a direct manner via the plate. On one side the sensors are mounted on a rigid mass (4), while the other end is free to move and is coupled to the plate, which comprises the plurality of push buttons. Fig. 1 shows a construction in which a sensor element corresponds to each push button. By exerting a force on one of the push buttons on the plate, the switch element below detects the activation. This is a primary detection. The other sensor elements, which are not directly under the activated key, detect the application of a force or displacement on the key in a reduced manner (wrinkle detection). The ripple detection of the coupled sensors is correlated with the distance between the different sensor elements and the key pressed (see Fig.2). In Fig. 2A the key (11) is pressed in the upper left corner. The observed signals as a function of time for each sensor element are shown in Fig. 2B. The signals are analogue transition signals. The closest sensor element obtains the detection with the maximum peak level of the sensor signal, which is referred to herein as 100% signal level detection. This is the primary detection. The sensor elements further away from the location of the pressed key detect a lower signal level (detection decreases further away from the location of activation). This is indicated by a smaller pulse from the sensor element and a signal level percentage less than 100%. The combination of these signals with a lower peak level forms the secondary detection. It is clear that the indicated value is merely an example of the possible detected signal amount, this will depend on the implementation of the plate and its attachment to the rigid surface. Each location of a pressure on the plate has its unique fingerprint of the combined signal detected by each sensor element. By analyzing all ripple observations (secondary detection), it is possible to determine which key has been pressed. In the example described, it is clear from the pattern obtained from the secondary detection that the upper left key was pressed even in the absence of the signal from the upper left sensor element. This combination of primary and secondary detection provides an error-tolerant detection of the activated key. This increases the availability and reliability of the keys on the keypad.
    The operating principle is further explained in Fig. 3, in which piezoelectric sensor elements are used. The edge of the plate is connected to the rigid surface (4) via a different structure. This confirmation is represented by a resistor (19), which indicates a resistance to movement of the plate with respect to the rigid surface. The sensor element (51) can be modeled as a spring (18) around a resistance to distortion and a voltage source Vi (17) (/ = 1,2,3), which is dependent on the force exerted on the piezoelectric element, to represent. A force F (16) is applied to the key on the keypad plate (2), which propagates along the plate and can be represented by F 'above the nearest adjacent sensor element and by F "above the next sensor element, where F is greater than F 'and F' is greater than F ", according to a certain relationship, which is defined by the distance between push buttons, the resistance of the connection between plate and rigid surface, material properties of the plate and the spring of the piezo element. This results in a gradual signal generation in neighboring keys, the signal level of which is a function of the same relationship as mentioned above. The relation also makes it possible to calculate F 'and F "from force F. The voltage-time graph (15) in Fig. 3B shows the voltage signals for the different voltage sources in the piezo elements when the left key (F1) The transition signal of V1 is larger than that of V2, which is greater than V3.The transition signal V2 and V3 can be calculated by means of V2 = f (V1, R12, ...) and V3 = f ( V1, R13, ....), wherein R12 represents the material characteristics and the distance between sensor element 1 and sensor element 2. R13 represents the material characteristics and the distance between sensor element 1 and sensor element 3. In Fig. 3C, the middle key is pressed (F2 The resulting voltage-time graph shows a different pattern of the voltage sources: V2 signal is now larger than VI and V3, while VI and V3 are equal, and the transition signal VI and V3 can be calculated by means of VI = f (V2 , R2i, ....) and V3 = f (V2, R23, ....), wherein R2i is repr is essential for the material characteristics and the distance between sensor element 2 and sensor element 1. R23 stands for the material characteristics and the distance between sensor element 2 and sensor element 3.
    Fig. 4 shows an embodiment of an analyzer (21) of the keypad, with a detection scheme for output control and error correction purposes. The sensor readers SR perform a conversion / level shift, if necessary, from the value coming from the sensor elements SE to the signal level expected by the analyzer. The different sensor readers each emit an electrical signal which is related to the signal obtained from their associated sensor element, which is then input to the analyzer (21). The analyzer contains various detector sets (23) at the input. Each set is arranged to perform a primary detection (24), a secondary detection (25) and optionally a test pattern detection (26) (utilizing information about this test pattern received from the controller, as described later). Each detector set takes a signal from the corresponding sensor reader. The parts of information from each detector set are combined in a processing block (27). Via the redundant information from primary (24) and secondary (25) detection, the key activation is determined and represented as a Boolean OFF key x signal (with x = 1, 2, 3, 4 in Fig. 4). From a consistent validation of (24) and (25) or test pattern detection, the error analysis is performed and represented as a Boolean OFF OK signal.
    Fig. 5 shows an embodiment of the logic circuits to be provided for analyzing the signal received from each sensor element. The signal from the sensor reader is first filtered through a filter (40) to get rid of irrelevant information, which may have been picked up. In case the test signal option is implemented, the test signal (41) is subtracted from the primary detection (24) and the secondary detection (25). In the primary detection, the peak level of all observed signals is detected (42). This gives a primary indication of which key has been activated. The level detected in the primary detection is communicated to the secondary level detection (43) and the test level detection (45) to set a related threshold level for secondary detection and optional test level detection. In the secondary detector (25) the levels of the secondary signals are detected. These levels are sent to the matrix (46), which combines the levels of all secondary detectors. The activated key can also be determined by means of the filled matrix and the known location of the key. This redundant information is combined in block (47) to the OFF key signal, which indicates which key has been pressed. On the other hand, in a case of a discrepancy between primary detection and secondary detection performed via an XNOR (48), it can be indicated via OFF OK that there is a failing element in the keypad. The Error Reporting block (49) is used in case test pattern detection is used.
    Various technologies can be used to implement the sensor elements. Piezoelectric elements or capacitive sensor elements are particularly well suited. However, the use of, for example, piezo-resistive, electrostatic, MEMS, thermoelectric or purely mechanical, pneumatic, hydraulic elements may also be provided.
    To provide this automatic test operation, in a preferred embodiment, the keypad further comprises a generator capable of generating test signals to be applied to the sensors. An illustration is provided in FIG. 6. The figure also shows a controller (30) which controls the generator, which comprises a generator drive (31) and a generator element (53). The generator drive GD performs conversion / amplification, if necessary, of the test signal from control (30) into a signal which can activate the generator elements GE. In Fig. 6, the generator element (53) is included in a key stack (3), which is a combination of a sensor element and the generator element. The test stack can be implemented in many possible ways, as described later. The controller provides the information about the test signal to the analyzer via a communication link 32. This makes it possible for the analyzer to determine a test signal that can be clearly distinguished from an activation signal.
    A varying signal, defined by the control, is sent from the generator to the sensor element. The sensor will detect an oscillating signal via the coupling, which corresponds to the frequency and the known proportional part of the amplitude of the signal transmitted by the generator.
    In order not to disadvantage normal push-button operation, the test signal is designed such that it can be easily distinguished from "usual" signals occurring during normal operation, e.g. by means of a specific level, signal pattern, ... This test signal, that clearly differs from a signal in normal operation, allows continuous automatic test operation. An option is to use a certain predetermined signal amplitude imposed by the generator. When the push button is operated, this level is changed and activation is detected. For example, an oscillation with a certain nominal level is imposed by the generator and information about this event is communicated to the analyzer. When the push button is operated, it dampens the oscillation and the lower level in the analyzer from the sensor element gives the trigger trigger. A second method for applying a test pattern is to use a key pattern imposed on the test signal, which is defined by the generator, the key pattern being different from the activation pattern of the push button. For example, the key pattern produced by the generator may be a sine wave, while the activation pattern is an exponential pulse. Another possible approach involves a resonance structure that is implemented by the generator, with a resonance frequency that differs from the operating frequency of the push button. When a frequency other than the resonance frequency is seen, this means that the push button is operated.
    The generated signal is picked up by the sensor elements via the coupling means. These signals can be analyzed and converted into an indication of the ability of the keypad to detect movement of the keypad (2). By doing this, the push buttons can be inherently tested.
    In accordance with the plurality of push buttons in a keypad, there may be a plurality of generators in a keypad, as indicated in FIG. 6. The controller (30) is able to define the scenario of generator activation and parameterization of the generator signal. From this a complex test pattern is supplied to the plate (2), which is picked up by all sensor elements. Observed signals are sent via the sensor reader (22) to the analyzer (21). At the same time, the controller sends the test scene data and signal parameter via connection (32) to the analyzer. Via these means, the analyzer detects whether the signals received from the sensor elements are correct. The Boolean signal OFF OK is set to the value true as long as no error is revealed by analyzing the automatic test signals from the keypad.
    The test scenario used is not limited to a specific scenario. In its simplest form it can apply a scanning operation with one generator switched on at the same time. Alternatively, more generators can be turned on simultaneously with the same or different parameters for the test signal for the different generators. It is important that the analyzer receives the correct test scenario so that it can correlate the test scenario with the expected signals from all sensor elements. The expected signals depend on the same relationship, distance and material properties as when linking the location of the applied key to neighboring sensor elements.
    The test pattern detection (26) in Fig. 4 receives the signal from the sensor reader (22). Fig. 5 shows a more detailed view of the test pattern detector. The signal from the sensor reader first passes through a filter (50), into which non-valuable information is filtered out. The signal is then processed by the test signal detection, which compares the received signal parameters with the information received via the communication interface (32) of the generator. The test signal level is determined and this is sent to the test level detector (45). This component analyzes whether the level corresponds to the expected level according to the coupling losses and operation of the key (threshold setting received from the primary level detection). The error reporting block (49) combines the information from the test level detector and the XNOR (48) or any other comparator. The error reporting block transmits signal (OFF OK) if the keypad is still working without errors. The test pattern can be used for automatic test, audible and haptic signal, as will be explained below.
    The functionality of analyzer and generator can in fact be implemented in various ways. Different technologies can be applied to implement the generator elements. Piezoelectric elements or capacitive sensor elements are particularly well suited. However, the use of, for example, piezo-resistive, electrostatic, MEMS, thermoelectric or purely mechanical, pneumatic, hydraulic elements may also be provided. The implementation of the sensor element and the generator element is not necessarily of the same type. The sensor element, the generator element and the manner of coupling must be adapted such that the sensor element is capable of measuring the signal generated by the generator element.
    Fig. 7 shows various possibilities for the stacking (3) and the positioning of the sensor element (51) and optionally the generator element (53). The in FIG. Stacks presented in 7A and 7B contain sensor elements only if the keypad is based solely on primary and secondary detection for fault tolerant operation. The coupling of the sensor elements has already been described previously. The in FIG. Embodiments presented in 7C and 7D include a generator element which, together with the sensor, forms a stack. The coupling (52) between the generator element and the sensor element can be implemented in a direct (Fig. 7C) or indirect (Fig. 7D) manner. By this means, a signal generated by the generator is fully or partially transmitted to the sensor element, which will detect this signal.
    The specific embodiments of Fig. 7, in which the generator element and sensor element are coupled, are now explained in more detail.
    FIG. 7A and FIG. 7B show a stack (3) of sensor elements (51) only, whereby detection of correct operation of the keypad is possible via ripple detection. The sensor element is attached at a first end to the rigid surface (4) at a defined position. At the second end the sensor element is coupled to the plate of the keypad on which the push buttons are located.
    FIG. 7C, the key stack (3) comprises a generator element (53) and a sensor element (51) which are directly coupled. The generator element is attached at one end to the rigid surface (4) at a defined position. At the other end, the generator element is coupled to the sensor element via a known and computable coupling (52). The sensor element is coupled at one end to the generator element and at the other end to the plate (3). A plurality of key stacks may be present in the key panel or key.
    FIG. 7D, the key stack (3) comprises a generator element (53) and a sensor element (51) which are coupled to each other via the keypad block plate. The generator element is attached at a first end to the rigid surface (4) at a defined position. The generator element is coupled to the plate at the other end. The sensor element is coupled to the same rigid surface at a first end and coupled to the plate (3) at the second end. The coupling between the generator element and the sensor element takes place via the plate. The plate is designed for a calculated link between generator and sensor. A plurality of key stacks may be present in the key panel.
    FIG. 8 shows an embodiment in which a piezoelectric sensor element 51 is used in the sensor for the push button. When the push button is pressed or hit, a resulting voltage is built up on both sides of the sensor element. This transition voltage signal is amplified and brought to the detector. A second piezoelectric sensor element is used as generator element 53 for the automatic test function of the push button. When a voltage is applied to generator element 53, this element distorts / stretches. This activation is coupled to the sensor element and further to the plate 2. If the input signal is generated in such a way that the vibration is generated in an audible frequency range (e.g. 10 kHz) and pulsed in a scenario for example, this causes a audible signal (eg SOS), defining the position of push buttons for visually impaired persons. The plate also advantageously oscillates with the input signal. This introduces palpable feedback to the user of the keys on the keypad.
    In order to drive the generator, a signal with characteristics is used that clearly deviates from the characteristics of the push-button activation signal, so that the generator signal can always be distinguished from the activation signal. In the embodiment shown in FIG. 8, an oscillating automatic test modulator (83) is used. The oscillation parameters (frequency and / or waveform and / or pattern) are defined by the parameter definition block for the automatic test signal (85). This driving signal with varying frequency ensures that possible resonance frequencies imposed by the environment in which the keypad is used do not interfere with the automatic test operation of the push buttons. The controller also sets the signal for an audible signal. This can be a varying frequency with human audible characteristics, which is set by the generator parameter block (86). This is supplied to the oscillating audible modulator (81) and when supplied to the plate, which reacts as a force transmission region to the air, this signal generates an audible sound. This signal provides the user with an indication of the location of the keypad or audible feedback from the keypad.
    The haptic signal modulator (82) generates a signal that has, for example, human-tangible characteristics (e.g., low-frequency pulses). When applied to the keypad plate, which reacts as a force transmission area for tactile perception, this signal generates a movement of this area which can be perceived by the user. This signal makes it possible for the user to position the push button or to get tactile feedback from the keypad.
    Triple redundancy is provided for detecting the keypad. The user can observe that the push buttons are at a specific visual location. The user can position the keypad by means of the audible signal and the user may feel whether his hand is indeed in contact with the keypad by observing the vibrating power transmission area.
    The generator driver (31) is provided with an electrical signal from a mixing device (84), which device combines the signals from three modulators into one electrical signal. The combined signal represents a complex signal that is relevant to the functionalities related to the individual modulators. The generator driver applies an electrical signal to the piezoelectric structure, which evokes a mechanical force in this structure.
    When the push button is not operated, the signal received by the analyzer from the sensor reader 22 is only from the generating piezoelectric element 53 and contains the test oscillation signal (optionally including audible and haptic signals) with varying frequency and a specific amplitude . The analyzer is adapted to analyze the received signal. The test signal received in the analyzer from the sensor element can be determined by the distance from the generator element to the sensor element and material properties of the elements included in the keypad. When the received signal corresponds to the determined value, a signal (OFF OK) is issued to indicate that the push button is operating as expected.
    Because a plurality of generators are present in the keypad and all can be connected to the sensor elements via the plate, a sensor element can detect the oscillation signal from one of the different generators. Each generator has a predetermined relationship due to its connection with and distance to each individual sensor. Thus, each individual sensor can be tested by means of a plurality of generators, which provide redundancy with respect to testing the piezo stack and the push button as such.
    The delivery of the audible, haptic and test signals is organized by the generator control blocks (80). This component schedules different test scenarios for the generator element (53), organizes the waveform of the audible signal and defines the waveform of the haptic feedback signal. The status of the scenarios is also passed to the analyzer (21) to enable the analyzer to synchronize with the generator block.
    Fig. 9 shows another embodiment in which the generator and sensor elements are a piezoelectric element. If this push button is not operated, the signal from the sensor element (51) is only related to the generator signal via the generator element (53) and the material of its coupling (52). When the push button is operated, the amplitude of the signal generated by the sensor element is changed. This is due to the force exerted on the key, which dampens the oscillation in the sensor element and reduces the amplitude. In addition, an energy pulse is created by the piezoelectric sensor element as soon as the stable position of the domes (90) is left and flipped to a metastable compressed position.
    In addition to a possibly generated haptic feedback signal (counting on dome stiffness), the key of FIG. 9 inherently some tactile feedback and the key is more resistant to unintended operation, since a higher force must be applied to overcome the stable state and the metastable state as long as force is applied to the key. As some distance must be covered by the test, the risk of unintended activation will be lower. Optionally, a housing around the key may prevent key operation due to placing an object against the key.
    The same principle can be applied to multiple keys (indicated by dashed lines) by adding the plate (2), in which the force or displacement will propagate to the adjacent stack.
    In the embodiment of Fig. 10, a sensor copper surface (indicated by "sens" copper), which forms the sensor element (51), is placed on a rigid surface. With a spacer (71) (e.g. insulator) a metal plate is placed at a fixed distance from the rigid surface 4. Note that the spacer (71) represents a practical implementation of resistor (19) shown in Fig. 3. No spacer is present above the copper surface, so that the metal plate (2) can be brought closer to the copper surface by pressing. On the other side of the insulating rigid surface, aligned with the sensor copper surface, a generator copper surface (indicated by "gen." Copper) is placed. This generator copper surface forms the generator element (53). The generator copper surface is connected to the generator driver (31), which is arranged to influence the capacity of the sensor copper surface relative to a reference or a load. The generator driver is driven with a test signal (73) with a specific test pattern defined by the controller.
    The sensor copper surface is connected to a sensor reader (22) which is adapted to measure the capacity. The sensor reader outputs a signal (72) that is representative of the capacitance value of the sensor copper block.
    FIG. 11 shows graphs related to the embodiment of FIG. 10 with capacitive perception. The capsizing method may differ, so that a subtraction operation is performed on the current signal and only the pattern of the test signal and the observed signal are targeted. The graph in FIG. 11C indicates the test pattern that is sent to the generator driver (pattern of test signal 73). The graph in FIG. 11B indicates the activation of the push button by the user. The graph in FIG. 11A indicates the pattern of the capacitance value output from the cap sensor reader (this is the pattern of the sensed signal 72). The change in the sensor head face capacity by the generator head face is observed in the sensor head face capacity value. The amount of change Atest (78) by the generator copper surface depends on the capacitor value and on the parasitic capacitance between the two blocks. A specific, unambiguous pattern is given to the generator. This pattern can be found in the capacitance measurement (72) shown in the graph of FIG. 11A, which has an Atest step. As long as this test-specific pattern and corresponding level change is detected by the analyzer, correct operation of the push button is guaranteed.
    When the metal plate is pressed (Fig. 11B), the capacitance value (shown in Fig. 11A) of the sensor copper surface changes in a different way than with the test pattern and with a different level (amount of change during activation: Aact (79) )). This level change triggers the operation of the push button in the analyzer. Key activation can be detected until the capacity value returns to its original level. While the metal plate is being pressed, the test pattern of FIG. 11C can still be detected in the sensed signal (72) pattern, as shown in the graph, which represents the capacitance measurement pattern (Fig. 11A). The amount of change through the generator surface is changed compared to when no push button is operated. The amount of change is now Atest @ act (74), it can be used as a redundant detection of the operation of the push button and automatic testing possibilities remain during the operation of the push button.
    The generator element 53, which supplies the automatic test signal to the push button, can be implemented using a wide variety of techniques. One option is a piezoelectric, electrostatic implementation, as in the previous examples, but also embodiments that use MEMS, thermal elements, etc. ... may be provided. Various techniques can also be applied to the sensor element 51. The sensor element must be sensitive to both the activation of the push button and the activation of the generator and to transmit both signals. The sensor element can be implemented by piezoelectric, piezo-resistive, electrostatic, thermoelectric, electromagnetic, MEMS, pneumatic, hydraulic, mechanical, ... elements.
    This device according to the invention comprises a key which is connected to only a sensor element or a key stack of generator element and sensor element for a push-button with automatic test operation of the sensor and analyzer in the push-button. The invention also proposes a method for continuous automatic test operation without interruption of the push button operation.
    Although some of the foregoing examples elaborate on a single push-button element, it should be emphasized that the wrinkle detection in a keypad comprising a plurality of push-buttons should also be considered and could be used as such, error-tolerant touch-stroke detection topology providing.
    FIG. 12 shows another embodiment of a stack that connects two generator elements (53) and two sensor elements (51) of a piezoelectric material in full redundancy. This positions the two generators on the outside of the structure. The sensors are then placed between the generators.
    The sensor elements are separated from the generator elements by means of an insulating material. This material isolates the generator element from the sensor element, while bending transfer is possible. This bending can come from the generator element or from exerting pressure on the structure (e.g., pressing the key).
    The sensor elements are then connected by means of a thin metal disk (95). This metal disk provides an electrical connection to both sensor elements. With proper dimensioning of this disc, it is also capable of producing audible vibrations when one of the generator elements or both receives an adjustment signal.
    FIG. 13 shows an embodiment of the invention in which the generator element and the sensor element are combined in one physical element, called generator sensor element (96).
    The separation between generator and sensor signal is performed in the generator driver and sensor reader. Two generator sensor elements or one generator element and one generator sensor element may be present. The stack has a rigid surface as a reference. A thin metal disk is located between the two elements.
    FIG. 14 shows an embodiment that does not use the same technology for the generator element and the sensor element. Here, the generator sensor element (96) is again based on the piezoelectric principle. When a voltage is applied, it flexes its metal base plate (52), thus varying the capacitance perceived by the capacitive sensor element (51).
    When the plate (2) is depressed, this can be observed in two different ways. The piezoelectric element (96) will induce an energy peak and the capacitive sensor element (51) will also detect a variance, as previously described in capacitive sensing. This structure gives the analyzer a redundant detection means.
    Although the invention is illustrated and described in detail in the drawing and the foregoing description, such an illustration and description should be construed as an illustration or example and not in a limiting sense. The foregoing description illustrates certain embodiments of the invention. It will be understood, however, that despite how detailed the foregoing appears in the text, the invention may be practiced in many ways. The invention is not limited to the disclosed embodiments.
    Other variations on the disclosed embodiments may be recognized and accomplished by those skilled in the art in practicing the claimed invention, by studying the drawings, disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the undefined word "a" does not exclude a plurality. A single processor or other unit can perform the functions of various items mentioned in the claims. The mere fact that certain measures are stated in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. A computer program can be stored / distributed on a suitable medium, such as an optical storage medium or a solid-state medium, supplied together with or as part of other hardware, but can also be distributed in other forms, such as via the internet or other wired or wireless telecommunication systems. Reference characters in the claims are not to be construed as limiting the scope of protection.
    权利要求:
    Claims (13)
    [1]
    CONCLUSIONS
    Key panel (5) comprising - a plate (2) comprising a plurality of push buttons (1) at given positions, the plate being adapted to propagate a force or displacement on a surface of the plate which plate is applied by operating one of the push buttons, - a plurality of sensor elements (51), which are arranged at given positions on a rigid surface (4) and are adapted to convert the force or displacement into corresponding electrical signals, the sensor elements of the plurality of sensor elements being electrically isolated from each other and mechanically coupled to each other via the plate, - connecting means for connecting the plate to the rigid surface, the connecting means providing resistance to movement of the plate relative to the rigid surface, - analysis means (21), comprising detection means for performing a primary detection on the electrical signals dealing with the sensor signal with the largest amplitude sensed by the closest sensor element when one of the push buttons is activated and to perform a secondary detection corresponding to sensor signals with smaller amplitude sensed by sensor elements further away from the activated push button, the distance between the given positions of the push buttons and the given positions of the sensor elements is exploited, the analysis means further adapted to determine which push button is activated using redundant information from the first and second detection.
    [2]
    The keypad according to claim 1, wherein the number of sensor elements is equal to the number of push buttons, so that one sensor element is provided for each push button, the sensor element being substantially located under the corresponding push button.
    [3]
    The keypad of claim 1, wherein the sensor elements are scattered without one-to-one relationship with the push buttons.
    [4]
    The keypad according to claim 1 or 2, comprising a generator means (53, 31), which is adapted to generate a test signal to be supplied to at least one of the sensor elements.
    [5]
    The keypad according to claim 4, comprising a controller (30) adapted to control the generator means and to define parameters for the test signal.
    [6]
    The keypad according to any of the preceding claims, wherein the sensor elements are piezoelectric sensors or capacitive sensor elements.
    [7]
    The keypad according to any of claims 4 to 6, wherein one of the sensor elements and one of the generator means are combined to form a stack (3).
    [8]
    The keypad according to any of claims 4 to 6, wherein more than one sensor element and more than one generator means are combined to form a stack.
    [9]
    The keypad according to claim 7 or 8, wherein a link (52) is provided between the sensor element and the generator means.
    [10]
    The keypad according to any of claims 7 to 9, wherein the sensor element and the generator means are integrated.
    [11]
    The keypad according to any of the preceding claims, comprising a spacer (71) for separating the plate (2) and the rigid surface (4) from each other.
    [12]
    A method for determining which push button is operated on a keypad, wherein the keypad (5) comprises a plate (2) comprising a plurality of push buttons (1) at given positions, the plate being arranged to be in a surface of the plate propagating a force or displacement exerted on the plate by actuating one of the push buttons, and comprising a plurality of sensor elements (51) disposed on a rigid surface (4) at given positions arranged for converting the force or displacement into corresponding electrical signals, the sensor elements being electrically isolated from each other and mechanically coupled to each other via the plate, the method comprising - receiving the electrical signals from the plurality of sensor elements performing on the electrical signals a primary detection corresponding to the sensor signal with the largest amplitude observed by the closest signal sensor element located when one of the push buttons is activated, - performing a secondary detection corresponding to sensor signals with a smaller amplitude detected by sensor elements further away from the activated push button, the distance between the given positions of the push buttons and the given positions of the sensor elements are exploited, - determining which push button on the keypad is operated using redundant information from the first and the second detection.
    [13]
    A method for determining which push button is operated on a keypad according to claim 12, comprising a step of generating a test signal and applying the test signal to the plurality of sensor elements.
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    同族专利:
    公开号 | 公开日
    EP2857972A1|2015-04-08|
    EP2857972B1|2017-12-06|
    BE1022330B1|2016-03-25|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
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    US20080278354A1|2007-05-11|2008-11-13|Peter Garrett|System and Apparatus for Dynamically Assigning Functions for Keys of a Computerized Keyboard Based on the Analysis of Keystrokes|
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    法律状态:
    2019-06-26| FG| Patent granted|Effective date: 20160325 |
    2019-06-26| MM| Lapsed because of non-payment of the annual fee|Effective date: 20181031 |
    优先权:
    申请号 | 申请日 | 专利标题
    EP13186986.9|2013-10-01|
    EP13186986.9A|EP2857972B1|2013-10-01|2013-10-01|Keypad and method for operating the same|
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