JP6291340B2 - Touch input device and input detection method - Google Patents

Description

  The present invention relates to a touch input device and an input detection method.

  There is known a touch input device such as a touch panel that receives an input by touching a display surface. As a method for detecting the XY coordinates of the touched position on the touch panel, a resistance film method, a capacitance method, a force sensor method, and the like are known. The force sensor type touch panel can detect the pressing force in addition to the XY coordinates.

  Patent Document 1 discloses that in a housing of a portable information device, a strain detection element is disposed so as to be mechanically coupled to the back surface of the housing with respect to a main surface on which a display screen and operation keys are provided. When the user applies a compressive load to the back surface and the side surface of the housing, the portable information device controls the function according to the electrical signal from the strain detection element.

  Patent Document 2 discloses that an information display device includes a flexible display panel, a flexible housing, and a pressure sensor for detecting bending stress of the housing. When the pressure sensor detects that the user has bent the casing, the information display device advances and displays the page of the content displayed on the display panel by one page.

JP2013-102416A JP 2003-015795 A

  The technology described above increases the cost of the apparatus because it is necessary to provide a sensor for detecting pressure in addition to an input device such as a touch pad or a touch panel for detecting main input.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a technique for recognizing the state of deformation of a panel using a plurality of force sensors that support the panel.

  A touch input device according to an aspect of the present invention is based on a panel, a plurality of force sensors that respectively support a plurality of positions of the panel, a housing that supports the plurality of force sensors, and outputs of the plurality of force sensors. A plurality of measured values indicating the force applied to the plurality of force sensors, respectively, and calculating a pressing force indicating the pressing force based on the plurality of measured values, and the panel based on the plurality of measured values and the plurality of positions. The pressure coordinates indicating the position of the pressure on the surface are calculated, and the force applied to the plurality of force sensors is calculated based on the pressure force, the pressure coordinates, and the plurality of positions, respectively, under the assumption that the pressure force is applied to the pressure coordinates. A calculation unit that calculates a plurality of estimated values to be shown and recognizes a deformation state of the panel based on the plurality of measured values and the plurality of estimated values.

1 is a block diagram illustrating a configuration of a touch panel according to Embodiment 1. FIG. The perspective view which shows the structure of the panel part 100. FIG. FIG. 3 is an exploded perspective view showing the configuration of the panel unit 100. 3 is a flowchart illustrating input detection processing according to the first embodiment. The top view which shows the coordinate system of the panel part 100 surface. FIG. 4 is a block diagram illustrating a configuration of a touch panel according to a second embodiment. 9 is a flowchart illustrating input detection processing according to the second embodiment. The flowchart which shows an initial load update process. 10 is a flowchart illustrating input detection processing according to the third embodiment. The curvature of the cover panel 120 is shown. The curve pattern table is shown. A specific example of the operation type is shown.

  The touch input device according to the present embodiment recognizes a touch operation based on the outputs of a plurality of force sensors that support the panel and not only uses the pressed coordinates as an input, but also indicates a state of deformation of the panel due to other than the touch operation. Recognize and use the status as input. For example, in a touch input device held by a user, the holding state can be used as an input.

  The touch input device of the present embodiment includes a touch panel, a touch pad, a portable information terminal (including a mobile phone, a smartphone, a camera, a personal computer, etc.), a vehicle (including a car navigation device), a kiosk terminal, an ATM (Automated Teller Machine). ), A vending machine (including an automatic ticket vending machine, etc.) and the like may be applied to a system that accepts an operation by pressing the touch surface. The touch input device according to the present embodiment may be applied to an HMI (Human Machine Interface) device that is connected to a computer and performs input / output.

  Hereinafter, examples of the touch panel to which the present invention is applied will be described.

  The touch panel of the present embodiment determines whether or not the cause of the force detected by the force sensor is a press (touch) on the touch surface, and determines that the cause is a press on the touch surface, based on the press. The calculated coordinates are output, and when it is determined that the cause is not the touch surface pressing, the calculated coordinates are not output.

  FIG. 1 is a block diagram illustrating the configuration of the touch panel according to the first embodiment.

  The touch panel of this embodiment includes a panel unit 100, a signal conversion unit 500, and a calculation unit 400. The calculation unit 400 includes a signal calculation unit 200, an application execution unit 300, and a display control unit 410.

  The panel unit 100 outputs four output signals indicating the forces applied to the four locations of the panel unit 100 to the signal conversion unit 500. The signal conversion unit 500 includes four A / D conversion units 510 corresponding to the four output signals output from the panel unit 100, respectively. The A / D converter 510 converts an analog output signal into a digital output value at a predetermined sample period by A / D conversion. The signal calculation unit 200 detects an input to the panel unit 100 based on the output value, and outputs the detected input to the application execution unit 300. The application execution unit 300 executes the application based on the detected input, generates screen information based on the execution result, and outputs the screen information to the display control unit 410. The display control unit 410 further generates a display signal for controlling the panel unit 100 based on the screen information, and outputs the display signal to the panel unit 100. Panel unit 100 displays a screen based on the display signal.

  The signal calculation unit 200 includes an input calculation unit 310 and a measurement expected value calculation unit 330. The input calculation unit 310 acquires an output value from the signal conversion unit 500 at a predetermined measurement cycle, and detects measurement values each indicating a variation in the output value. Further, the input calculation unit 310 assumes that the cause of the measurement value is a pressure on the surface of the panel unit 100, and calculates a pressing force indicating a pressing force based on the measurement value. Further, the input calculation unit 310 assumes that the cause of the measurement value is a pressure on the surface of the panel unit 100, and calculates the press coordinates that are the coordinates of the press based on the measurement value and the pressing force. The measurement expectation value calculation unit 330 assumes that the cause of the pressing force is a pressure on the surface of the panel unit 100, and estimates the measurement value based on the pressing force and the pressing coordinates, thereby measuring the expected value of the measurement value. Calculate the expected value. The determination unit 340 determines whether the cause of the pressing force is a pressure on the surface of the panel unit 100 based on the measured value and the expected measurement value.

  The display control unit 410 generates a display signal for controlling the display of the panel unit 100 based on the screen information from the application execution unit 300, and outputs the display signal to the panel unit 100.

  The calculation unit 400 is realized by a computer, for example. This computer has a memory for storing programs and data, and a microprocessor such as a CPU (Central Processing Unit) that executes processing of the signal calculation unit 200, the application execution unit 300, and the display control unit 410 according to the program. This program may be stored in a computer-readable medium and read from the medium to the computer. The signal calculation unit 200, the application execution unit 300, and the display control unit 410 may be realized by different microprocessors. Further, the application execution unit 300 and the display control unit 410 may be realized by a single microprocessor. In addition, a program corresponding to each of the signal calculation unit 200, the application execution unit 300, and the display control unit 410 may be prepared. Note that at least one of the signal calculation unit 200, the application execution unit 300, and the display control unit 410 may be realized by a dedicated electronic circuit. In addition, at least one of the application execution unit 300 and the display control unit 410 may be provided outside the touch panel. In this case, the signal calculation unit 200 has a communication interface and performs communication with the outside of the touch panel. Note that the signal calculation unit 200 may include a signal conversion unit 500. The touch panel may further include an audio output unit that outputs audio based on an instruction from the application execution unit 300.

  FIG. 2 is a perspective view showing the configuration of the panel unit 100, and FIG. 3 is an exploded perspective view showing the configuration of the panel unit 100.

  The panel unit 100 according to this embodiment includes a display panel 110, a cover panel 120, four force sensors 130, and a base unit 150. A display panel 110 is disposed on the base unit 150. The display panel 110 of this embodiment is an LCD (Liquid Crystal Display), but may be an organic EL (Electro-Luminescence) display or the like. The shape of the display area of the display panel 110 of this embodiment is a rectangle.

  Further, a plurality of force sensors 130 are arranged around the display panel 110 on the base part 150. In this embodiment, four force sensors 130 are arranged corresponding to the four vertices of the display panel 110, respectively. The force sensor 130 of this embodiment is a piezoelectric element.

  A cover panel 120 is provided to face the surface of the display panel 110. The touch surface is the surface of the cover panel 120. The cover panel 120 of the present embodiment has a flat plate shape, and the surface shape thereof is a rectangle. The four force sensors 130 respectively support the vicinity of the four vertices on the back surface of the cover panel 120. Thereby, there is a predetermined interval between the back surface of the cover panel 120 and the front surface of the display panel 110. The cover panel 120 transmits the display on the display panel 110. The cover panel 120 is realized by glass or plastic, for example.

  A signal conversion unit 500 is further provided on the base unit 150. The signal conversion unit 500 is connected to the four force sensors 130 via signal lines. Note that the signal conversion unit 500 may not be disposed on the base unit 150 as long as it is connected to the force sensor 130. A signal operation unit 200, an application execution unit 300, and the like may be further provided on the base unit 150.

  The panel corresponds to the cover panel 120 or the like.

  The four force sensors 130 may support the vicinity of the four vertices on the back surface of the display panel 110, and the front surface of the display panel 110 may be in contact with the back surface of the cover panel 120.

  Further, the shape of the display area of the display panel 110 may be other than a rectangle. Further, the number of force sensors 130 may be other than four. The force sensor 130 may be a capacitor, a strain gauge, or the like.

  In order to remove an unstable operation region due to a minute pressure, a slight pressure is applied to the cover panel 120 in the direction of the base portion 150 as an initial load. In order to apply an initial load, an elastic body such as a spring may be provided between the cover panel 120 and the base portion 150. When the cover panel 120 is installed, the output value when the surface of the cover panel 120 is not touched is measured and stored in the input calculation unit 310 as an initial load.

  The cover panel 120 covers the surface of the display panel 110 and protects the surface of the display panel 110. Furthermore, the surface of the cover panel 120 receives a press (touch) by the user. The four force sensors 130 output an output signal, which is an electrical signal corresponding to the force received from the cover panel 120, to the signal conversion unit 500, thereby continuously measuring the force.

  The signal calculation unit 200 performs an input detection process for detecting an input based on an output from the force sensor 130 at every predetermined input detection cycle.

  The touch panel further has a housing. The signal conversion unit 500, the signal calculation unit 200, the application execution unit 300, and the display control unit 410 are housed in a housing and are fixed to the housing. Of the panel unit 100, the display panel 110, the four force sensors 130, and the base unit 150 are accommodated in the casing, and the cover panel 120 covers the opening of the casing. The base part 150 is fixed to the housing.

  FIG. 4 is a flowchart illustrating the input detection process according to the first embodiment.

  The input calculation unit 310 stores in advance initial loads Fw1, Fw2, Fw3, and Fw4 corresponding to the four force sensors 130, respectively. When the input detection process is started, the input calculation unit 310 acquires output values G1, G2, G3, and G4 corresponding to the four force sensors 130 from the signal conversion unit 500 (S110), and G1, G2, The measured values F1, F2, F3, and F4 are calculated by subtracting Fw1, Fw2, Fw3, and Fw4 from G3 and G4, respectively (S120). Thereby, the influence of the initial load can be removed from the output value. Note that the input calculation unit 310 may detect the output values G1, G2, G3, and G4 as measured values F1, F2, F3, and F4, respectively. Thereafter, the input calculation unit 310 calculates a pressing force Fs that is the sum of the measured values F1, F2, F3, and F4 (S130). When it is assumed that the cover panel 120 is a rigid body and the cause of the measurement value is a pressure on the surface of the cover panel 120, the pressing force Fs indicates a force that presses the surface of the cover panel 120. Thereafter, the input calculation unit 310 determines whether or not the pressing force is equal to or greater than a predetermined pressing force threshold Fth (S140). Thereby, even if the input calculation part 310 detects the pressing force smaller than a pressing force threshold value, it does not determine with the press having been performed but can reduce misdetection.

  When it is determined that the pressing force is not equal to or greater than the pressing force threshold (S140: NO), the input calculation unit 310 shifts the process to S110. When it is determined that the pressing force is equal to or greater than the pressing force threshold (S140: YES), the input calculation unit 310 assumes that the cause of the measured value is the pressing on the surface of the cover panel 120, and the coordinates of the touched point. The pressed coordinates are calculated (S150). A method for calculating the press coordinates will be described later.

  Thereafter, the expected measurement value calculation unit 330 calculates the expected measurement value, which is the expected value of the measurement value, assuming that the cover panel 120 is a rigid body and that the pressing force is applied to the pressed coordinates (S210). . Note that the expected measurement value may be referred to as an estimated value. A method for calculating the expected measurement value will be described later. The determination unit 340 calculates a difference value between the measurement value and the measurement expected value, and determines whether or not the difference value satisfies a predetermined difference condition (S220). A method for determining the difference value will be described later.

  When it is determined that the difference value satisfies the difference condition (S220: YES), the determination unit 340 recognizes that the cause of the pressing force is the pressure on the surface of the cover panel 120, and the application execution unit 300 determines the pressing coordinates and the pressing force. (S230), and this flow ends. When it is determined that the difference value does not satisfy the difference condition (S220: NO), the determination unit 340 recognizes that the cause of the pressing force is not pressing on the surface of the cover panel 120, and outputs the pressing coordinates and the pressing force. This flow is finished.

  Upon receiving the notification of the pressing coordinates and the pressing force, the application execution unit 300 executes an application process using the pressing coordinates and the pressing force. For example, the application execution unit 300 may select an object displayed at the pressing coordinate, or may draw an object having a size based on the pressing force at the pressing coordinate.

  The above is the input detection process. According to this input detection process, is the input measured by the force sensor 130 a normal input due to the pressure on the surface of the cover panel 120 or an abnormal input due to something other than a pressure on the surface of the cover panel 120? Can be distinguished.

  Hereinafter, the calculation method of a press coordinate is demonstrated.

  FIG. 5 is a plan view showing a coordinate system on the surface of the panel unit 100.

  In this embodiment, the center of the display area of the display panel 110 is the origin, and the surface of the display panel 110 is the XY plane. Of the four force sensors 130, the force sensor 130 arranged in the first quadrant of the XY plane is set as S1, the force sensor 130 arranged in the second quadrant is set as S2, and the force sensor 130 arranged in the third quadrant. Is S3, and the force sensor 130 arranged in the fourth quadrant is S4. In addition, measurement values obtained from the force sensors S1, S2, S3, and S4 are F1, F2, F3, and F4, respectively.

  Here, the distance on the surface of the panel unit 100 is defined in units of pixels in the display panel 110. The size of the display area of the display panel 110 in the X direction is Wd, and the size of the display area in the Y direction is Hd. In this embodiment, Wd is 320 and Hd is 240. Further, the distance between the two force sensors 130 adjacent in the X direction (the distance between S1 and S2, the distance between S3 and S4) is Ws, and the distance between the two force sensors 130 adjacent in the Y direction. Let Hs be the distance (distance between S1 and S4, distance between S2 and S3). In this example, Ws is 422 and Hs is 266. Furthermore, if the distance in the X direction from the origin to the force sensor 130 is Xs, Xs is Ws / 2, and if the distance in the Y direction from the origin to the force sensor 130 is Ys, Ys is Hs / 2. In this embodiment, Xs is 211 and Ys is 133.

  In the calculation method of the pressing coordinates, the input calculation unit 310 is based on the coordinates of the force sensors S1, S2, S3, S4 represented by Xs and Ys, the measured values F1, F2, F3, F4, and the pressing force Fs. The press coordinates PX and PY are calculated using the following formula.

  Hereinafter, a method for calculating the expected measurement value will be described.

  The expected measurement value calculation unit 330 distributes the pressing force Fs to the coordinates of the force sensors S1, S2, S3, and S4 represented by Xs and Ys, thereby measuring corresponding to the force sensors S1, S2, S3, and S4, respectively. Expected values E1, E2, E3, and E4 are calculated. Here, a description will be given using a specific example when (35.000, 52.100, 30.650, 2.250) is obtained as the measurement values (F1, F2, F3, F4). In this case, the pressing force Fs is 120, and the pressing coordinates (PX, PY) are (−80, 60) by the above-described calculating method of the pressing coordinates.

  The expected measurement value calculation unit 330 calculates an expected origin measurement value that is an expected value of the measured value when the origin is pressed with a pressing force. Here, the origin measurement expected values corresponding to the force sensors S1, S2, S3, and S4 are O1, O2, O3, and O4, respectively. The origin measurement expected value is expressed by the following equation.

O1 = O2 = O3 = O4 = Fs / 4
= 120/4 = 30

  Thereafter, the expected measurement value calculation unit 330 calculates the influence TempX by the X coordinate of the pressed coordinate using the following equation.

TempX = PX x O1 / Xs
= -80 x 30/211 = -11.374

  Thereafter, the expected measurement value calculation unit 330 uses the following formula to reflect TempX in the origin measurement expected value, so that the temporary measurement expected values PreE1, PreE2, and PreE3 corresponding to the force sensors S1, S2, S3, and S4, respectively. , PreE4 is calculated.

PreE1 = O1 + TempX
= 30 + (-11.374) = 18.626
PreE2 = O2-TempX
= 30-(-11.374) = 41.374
PreE3 = O3-TempX
= 30-(-11.374) = 41.374
PreE4 = O4 + TempX
= 30 + (-11.374) = 18.626

  Thereafter, the measurement expected value calculation unit 330 calculates the influences TempY1 and TempY2 due to the Y coordinate of the pressed coordinates using the following equation.

TempY1 = PY × PreE1 / Ys
= (60 × 18.626) / 133 = 8.403
TempY2 = PY × PreE2 / Ys
= (60 x 41.374) / 133 = 18.665

  Thereafter, the expected measurement value calculation unit 330 calculates expected measurement values E1, E2, E3, and E4 by reflecting TempY1 and TempY2 in the origin measurement expected value using the following equation.

E1 = PreE1 + TempY1
= 18.626+ (8.403) = 27.029
E2 = PreE2 + TempY2
= 41.374+ (18.665) = 60.039
E3 = PreE3-TempY2
= 41.374- (18.665) = 22.709
E4 = PreE4-TempY1
= 18.626- (8.403) = 10.223

  According to the above calculation method of the expected measurement value, the measured value when the pressing force is applied to the pressing coordinate is estimated by allocating the pressing force Fs to the coordinates of the four force sensors 130 based on the pressing coordinate. can do.

  Hereinafter, a method for determining the expected measurement value will be described.

  The determination unit 340 compares the measured value with the expected measurement value. For example, the determination unit 340 calculates the difference values D1, D2, D3, and D4 by subtracting the expected measurement values E1, E2, E3, and E4 from the measured values F1, F2, F3, and F4, respectively. If the cause of the pressing force is a pressing coordinate, each of D1, D2, D3, and D4 approaches 0.

  At this time, the difference condition is that the absolute value of all the difference values is equal to or less than a predetermined difference threshold value. The difference threshold value is sufficiently smaller than the magnitude of the pressing force, for example, 2% of the magnitude of the pressing force. In this specific example, (D1, D2, D3, D4) becomes (+7.971, −7.9939, +7.941, −7.973). If the difference threshold is 2.4, the determination unit 340 determines that the difference value does not satisfy the difference condition because the absolute value of at least one difference value exceeds the difference threshold.

  If only the high-precision force sensor 130 is used for the touch panel, vibrations are transmitted to the force sensor 130 when a person walks near the touch panel or touches a desk on which the touch panel is placed. Detection may occur. According to the present embodiment, the cause of the output of the force sensor 130 is the pressure on the surface of the cover panel 120 or other than the pressure on the surface of the cover panel 120 based on the expected measurement value without providing any special hardware. By determining whether or not, erroneous detection can be prevented.

  The initial load may change due to distortion of the touch panel housing, and correct pressing coordinates may not be obtained. For example, in a state where the touch panel is used while standing or a book or palm is placed on the surface of the cover panel 120, an initial load different from a preset value is applied to the force sensor 130 while the state continues. . Therefore, the pressure on the cover panel 120 surface may not be measured correctly.

  When the touch panel of the present embodiment detects a force other than pressing on the surface of the cover panel 120 and determines that the detected force is stable for a certain period of time, an initial load is calculated based on the detected force. Update.

  In the present embodiment, the difference from the first embodiment will be mainly described.

  FIG. 6 is a block diagram illustrating a configuration of the touch panel according to the second embodiment.

  Compared to the touch panel of the first embodiment, the touch panel of the second embodiment includes a calculation unit 400b instead of the calculation unit 400. Compared to the calculation unit 400, the calculation unit 400 b includes a signal calculation unit 200 b instead of the signal calculation unit 200. Compared with the signal calculation unit 200, the signal calculation unit 200 b newly includes an initial load update unit 420. When a force other than pressing on the surface of the cover panel 120 is detected, the initial load update unit 420 updates the initial load based on the force.

  The initial load update unit 420 outputs the output value from the signal conversion unit 500 to the input calculation unit 310 as an initial load when the panel unit 100 is installed or periodically measured and the cover panel 120 is not touched. To do. The input calculation unit 310 stores the initial load. Thereafter, the input calculation unit 310 calculates a measurement value from the output value of the signal conversion unit 500 using the initial load.

  The signal calculation unit 200b performs an input detection process for detecting an input based on an output from the force sensor 130 at every predetermined input detection cycle.

  FIG. 7 is a flowchart illustrating input detection processing according to the second embodiment.

  Similar to the input detection process of the first embodiment, the signal calculation unit 200b executes the processes of S110 to S140.

  When it is determined that the pressing force is not equal to or greater than the pressing force threshold (S140: NO), the input calculation unit 310 executes an initial load update process (1) for updating the initial load (S160), and the process proceeds to S110. . The initial load update process (1) will be described later. When it is determined that the pressing force is equal to or greater than the pressing force threshold value (S140: YES), the input calculation unit 310 executes the processing of S150 to S220 as in the input detection processing of the first embodiment.

  When it is determined that the difference value satisfies the difference condition (S220: YES), the determination unit 340 executes the same S230 as in the first embodiment and ends this flow. When it is determined that the difference value does not satisfy the difference condition (S220: NO), the initial load update unit 420 executes an initial load update process (2) similar to the initial load update process (1) (S310), This flow is finished. The initial load update process (2) will be described later.

  FIG. 8 is a flowchart showing the initial load update process.

  The initial load update process is an initial load update process (1) of S160 described above and an initial load update process (2) of S310 described above. The initial load update unit 420 stores two values of N in order to indicate a monitoring period of length of measurement period × N. N used for the initial load update process (2) is larger than N used for the initial load update process (1). That is, the monitoring period of the initial load update process (2) is longer than the monitoring period of the initial load update process (1). The monitoring period of the initial load update process (1) is, for example, 0.5 seconds or less. The monitoring period of the initial load update process (2) is, for example, 1 minute. The input calculation unit 310 stores an initial load Fwi (i = 1, 2, 3, 4).

  The initial load updating unit 420 sets the counter value n to 1 and starts the monitoring period of the measured value Fi (S410). Thereafter, the input calculation unit 310 acquires Fi from the input calculation unit 310 (S420). Here, Fi is a value obtained by subtracting the initial load Fwi from the output value Gi as described above. Thereafter, the initial load update unit 420 determines whether or not Fi satisfies a predetermined change condition (S440). The changing condition is that Fi is stable. For example, the change condition is that any magnitude of Fi is equal to or greater than a predetermined deviation threshold, and the magnitude of fluctuation of Fi during the monitoring period is equal to or less than a predetermined fluctuation amount threshold.

  For example, in S440, the initial load update unit 420 determines whether any absolute value of Fi is greater than or equal to the deviation threshold. When it is determined that the absolute values of all Fi are not greater than or equal to the deviation threshold, the initial load update unit 420 determines that Fi does not satisfy the change condition. When any absolute value of Fi is greater than or equal to the deviation threshold, the initial load update unit 420 determines whether n is 1. When it is determined that n is 1, the initial load update unit 420 stores Fi as a reference value. When it is determined that n is not 1, the initial load update unit 420 calculates the fluctuation amount of Fi from the reference value by subtracting the reference value from Fi, and the absolute value of the fluctuation amount is equal to or less than the fluctuation amount threshold value. It is determined whether or not. When it is determined that the absolute value of the fluctuation amount is not equal to or less than the fluctuation amount threshold value, the initial load update unit 420 determines that Fi does not satisfy the change condition. In addition, when it is determined that the absolute value of the initial load fluctuation amount is equal to or less than the initial load fluctuation threshold, the initial load update unit 420 determines that Fi satisfies the change condition.

  When it is determined that Fi does not satisfy the change condition (S440: NO), the initial load updating unit 420 does not update the initial load and ends this flow. When it is determined that Fi satisfies the change condition (S440: YES), the initial load update unit 420 adds 1 to n (S450), and determines whether n is N or less (S460). Thereby, the initial load update unit 420 can detect that Fi is stable in the monitoring period.

  When it is determined that n is equal to or less than N (S460: YES), the initial load update unit 420 shifts the process to S420. When it is determined that n is not N or less (S460: NO), the initial load update unit 420 calculates the Fwi correction amount ΔFai based on Fi (S510). For example, the initial load updating unit 420 calculates the average of N Fi acquired during the monitoring period as ΔFai.

  The initial load update unit 420 updates Fwi by adding ΔFai to Fwi, outputs the updated Fwi to the input calculation unit 310 (S520), and ends this flow.

  In S440, the initial load update unit 420 may not immediately end the initial load update process when it is determined that Fi does not satisfy the change condition. For example, in S440, the initial load update unit 420 counts the number of nonconformities, which is the number of times that Fi is determined not to satisfy the change condition during the monitoring period, and updates the initial load when the number of nonconformities exceeds a predetermined nonconformity count threshold. The process may be terminated, and the process may proceed to S460 when the number of nonconformities is equal to or less than the nonconformance count threshold. The nonconformity frequency threshold is sufficiently smaller than N, for example, N / 10. Thereby, even if Fi slightly fluctuates during the monitoring period, it can be determined that Fi is stable.

  The above is the initial load update process.

  Since the initial load update process (1) is executed in a state where the pressing force is smaller than the pressing force threshold value, the initial load is updated based on a change in measured value caused by natural distortion of the touch panel housing. Since the initial load update process (2) is executed in a state where the pressing force is equal to or greater than the pressing force threshold value, the initial load is updated based on a change in the measured value due to some force applied to the casing of the touch panel. In the initial load update process (2), the initial load update unit 420 may shorten the monitoring period by ending the monitoring period in response to an input from the user.

  According to the present embodiment, it is possible to detect that the deviation of the measured value is stable and correct the initial load based on the measured value. For example, the touch panel of the present embodiment may be applied to a tablet terminal, the tablet terminal may be leaned against another object, and the back surface of the tablet terminal may be supported by the object. In this case, the cover panel 120 is distorted. When the touch panel of this embodiment is stabilized in a state where the cover panel 120 is distorted, the accuracy of the pressing force and the pressing coordinates can be improved by calculating a new initial load. In addition, the initial load can be updated each time the touch panel support method is changed and stabilized.

  The touch panel of the present embodiment executes a predetermined process when a force other than pressing on the surface of the cover panel 120 is detected.

  In the present embodiment, the difference from the first embodiment will be mainly described.

  The signal calculation unit 200 performs an input detection process for detecting an input based on an output from the force sensor 130 at every predetermined input detection cycle.

  FIG. 9 is a flowchart illustrating input detection processing according to the third embodiment.

  Similar to the input detection process of the first embodiment, the signal calculation unit 200 executes the processes of S110 to S220.

  When it is determined that the difference value satisfies the difference condition (S220: YES), the determination unit 340 determines that a touch operation, which is an input indicating the pressed coordinates on the surface of the cover panel 120, has been performed, and is the same as in the first embodiment. S230 is executed and this flow is ended. When it is determined that the difference value does not satisfy the difference condition (S220: NO), the determination unit 340 determines that a housing operation that is an input that does not indicate the pressed coordinates on the surface of the cover panel 120 has been performed, and based on the difference value. The chassis operation recognition process for recognizing the chassis operation is performed, and the chassis operation information indicating the recognized chassis operation is output to the application execution unit 300 (S320), and this flow is terminated. The housing operation indicates a state of the cover panel 120 due to a force applied to the housing from the outside. The chassis operation information includes, for example, an operation type that is a type of chassis operation.

  The application execution unit 300 that has received the notification of the chassis operation information executes a specific process (function) associated with the chassis operation information. When the touch panel is an information communication terminal such as a smartphone or a tablet terminal, the specific process is, for example, sleep release, screen scroll, page feed, lock, display size change, volume change, and the like. For example, the user can execute functions such as canceling sleep, scrolling the screen, page turning, changing the display size, changing the volume, and the like simply by grasping the information communication terminal. Further, when the information communication terminal receives an impact due to dropping, a function such as locking can be executed.

  Details of the case operation recognition process will be described below.

  FIG. 10 shows the curve of the cover panel 120 due to the force applied to the housing 600 of the touch panel.

  The touch panel housing 600 has a shape that can be held by a user's hand and has flexibility. The cover panel 120 is also flexible. Here, a case where the housing 600 and the cover panel 120 have a vertically long shape will be described. As in FIG. 5, the center of the surface of the cover panel 120 is the origin, the right direction of the surface is the X direction, and the upward direction of the surface is the Y direction. Further, the surface direction of the cover panel 120 is defined as the Z direction. The housing 600 has an opening in the Z direction. The cover panel 120 is provided in the opening and is supported by force sensors S1, S2, S3, and S4. The force sensors S1, S2, S3, and S4 are supported by the casing 600 via the base portion 150 and the like.

  Here, it is assumed that the case 600 is not in contact with the cover panel 120 when no force is applied to the case 600 and the cover panel 120. When a force is applied to the housing 600 and the housing 600 is distorted and contacts the cover panel 120, the cover panel 120 may be bent. For example, when the user grips the side surface of the casing 600 or grips the cover panel 120 and the casing on the back side thereof, the cover panel 120 is curved.

  At this time, any one of the straight lines L1, L2, L3, and L4, which are symmetry axes on the surface of the cover panel 120, becomes a mountain (convex in the Z direction) or a valley (convex in the -Z direction). The straight line L1 is a diagonal line passing through the positions of the force sensors S1 and S3 on the surface of the cover panel 120. The straight line L2 is a diagonal line passing through the positions of the force sensors S2 and S4 on the surface of the cover panel 120. The straight line L3 is the X axis. The straight line L4 is the Y axis.

  Since the measurement expected value is calculated on the assumption that the cover panel 120 is a rigid body, when the cover panel 120 is bent, the measurement value deviates from the measurement expected value, and the degree of bending appears as a difference value. The curvature can be classified into patterns according to straight lines that are peaks or valleys and whether the straight lines are peaks or valleys. Hereinafter, this pattern is referred to as a curved pattern. Furthermore, the curved pattern can be represented by a combination of signs of difference values. The determination unit 340 stores in advance a bending pattern table in which the bending pattern and the operation type are associated with each other.

  FIG. 11 shows a curve pattern table.

  The curve pattern table has an entry for each curve pattern. The entry corresponding to one curve pattern includes a curve pattern number (No) that is an identifier of the curve pattern, a sign condition that is a combination of the difference values D1, D2, D3, and D4 indicating the curve pattern, and the curve pattern. And an operation type identifier indicating the operation type associated with. There are 16 combinations of signs of the difference values D1, D2, D3, and D4, but the curve pattern # 1 when the signs of the difference values D1, D2, D3, and D4 are all positive, and the difference values D1, D2 , D3, and D4 are all negative, and the bending pattern # 1 does not theoretically exist. Therefore, no operation type is assigned to these bending patterns.

  Here, in the bending pattern table, it is assumed that operation types OA, OB, OC, and OD are assigned to the bending patterns # 11, # 6, # 4, and # 13, respectively.

  In the chassis operation recognition process, the determination unit 340 refers to the curve pattern table, selects a code condition that matches the calculated codes of the four difference values, and includes a chassis operation including an operation type identifier corresponding to the code condition. Information is output to the application execution unit 300.

  The determination unit 340 may output a curve pattern number or a sign of a difference value as the deformation state of the cover panel 120 based on the case operation recognition process.

  FIG. 12 shows a specific example of the operation type.

  The operation type OA shown in (a) corresponds to the curve pattern # 11. In the curved pattern # 11, the cover panel 120 is curved with the straight line L1 as a valley, and the signs of the difference values D1, D2, D3, and D4 are −, +, −, and +, respectively. For example, a -Z direction force is applied to the point HA1 near the force sensor S4 on the surface of the cover panel 120, and an X direction force is applied to the point HA2 near the force sensor S2 on the side surface of the touch panel. Is the case. In other words, when the user holds the touch panel by pressing the lower right surface of the cover panel 120 and the casing 600 on the back side of the cover panel 120 and presses the upper portion of the left side surface of the casing 600, the determination unit 340 Recognize OA.

  The operation type OB shown in (b) corresponds to the curve pattern # 6. In this curved pattern, the cover panel 120 is curved with the straight line L2 as a valley, and the signs of the difference values D1, D2, D3, and D4 are +, −, +, and −, respectively. For example, a -Z direction force is applied to the point HB1 near the force sensor S3 on the surface of the cover panel 120, and a -X direction force is applied to the point HB2 near the force sensor S1 on the side surface of the touch panel. This is the case. In other words, when the user holds the touch panel by pressing the lower left side of the surface of the cover panel 120 and the casing 600 on the back side and presses the upper part of the right side of the casing 600, the determination unit 340 determines the operation type OB. Recognize

  The operation type OC shown in (c) corresponds to the curve pattern # 4. In this curved pattern, the cover panel 120 is curved with the straight line L4 as a valley, and the signs of the difference values D1, D2, D3, and D4 are +, +, −, and −, respectively. For example, a -Z direction force is applied to the point HC1 near the midpoint of the force sensors S3 and S4 on the surface of the cover panel 120, and the X direction is applied to the point HC2 near the force sensor S2 on the side surface of the touch panel. This is a case where a force is applied and a force in the −X direction is applied to the point HC3 in the vicinity of the force sensor S1 on the side surface opposite to the HC2. In other words, when the user holds the touch panel by pressing the lower part of the front surface of the cover panel 120 and the casing 600 on the back side and presses the upper part of the left side and the upper part of the right side of the casing 600, the determination unit 340 Recognizes the operation type OC.

  The operation type OD shown in (d) corresponds to the curve pattern # 13. In this curved pattern, the cover panel 120 is curved with the straight line L4 as a valley, and the signs of the difference values D1, D2, D3, and D4 are −, −, +, and +, respectively. For example, a -Z direction force is applied to a point HD1 near the midpoint of the force sensors S1 and S2 on the surface of the cover panel 120, and an X direction force is applied to the point HD2 near the force sensor S3 on the side surface of the touch panel. This is the case where a force is applied and a force in the −X direction is applied to the point HD3 in the vicinity of the force sensor S4 on the side surface opposite to the HD2. In other words, when the user holds the touch panel by pressing the upper part of the front surface of the cover panel 120 and the casing 600 on the back side, and presses the lower part of the left side and the lower part of the right side of the casing 600, the determination unit 340 Recognizes the operation type OD.

  The application execution unit 300 stores an association between each operation type and a process in advance. The application execution unit 300 performs processing corresponding to the operation type recognized by the determination unit 340.

  For example, the application execution unit 300 scrolls up the screen according to the operation type OC that presses the upper portions of the left and right side surfaces of the housing 600, and according to the operation type OD that presses the lower portions of the left and right side surfaces of the housing 600. The screen may be scrolled downward. Further, the application execution unit 300 may enlarge the display size of images and characters displayed on the display panel 110 according to the operation type OC, and reduce the display size according to the operation type OD. Further, the application execution unit 300 may increase the volume according to the operation type OC and decrease the volume according to the operation type OD.

  Further, when the determination unit 320 recognizes the operation type, the determination unit 320 may recognize the pressing force at that time as the operation amount and notify the application execution unit 300 of the operation type and the operation amount. In this case, the application execution unit 300 performs processing according to the operation type and the operation amount.

  For example, when the operation type indicates scrolling in a specific direction on the screen, the application execution unit 300 determines the scroll speed based on the operation amount. When the operation type indicates a change in the display size of a specific object on the screen, the application execution unit 300 determines the changed display size based on the operation amount. When the operation type indicates a change in volume, the application execution unit 300 determines the changed volume based on the operation amount. According to such an operation, the user can input the operation amount to the touch panel by the gripping force of the touch panel.

  Further, as described above, since the input detection process is performed for each input detection cycle, the determination unit 340 may recognize a continuous chassis operation that is a continuously recognized chassis operation. The determination unit 340 stores a continuous state indicating whether or not a specific operation type has been recognized in the previous input detection process. In the curve pattern table, the operation type corresponding to the continuous housing operation is defined in advance as a specific operation type.

  For example, in the input detection process, when the specific operation type is not recognized, the determination unit 340 clears the continuous state. In the subsequent input detection process, when the determination unit 340 recognizes the specific operation type, the determination unit 340 stores the specific operation type recognized in the continuous state, and measures the duration time during which the specific operation type continues. Start.

  Thereafter, in the input detection process when the value is set to the continuous state, the determination unit 340 determines whether or not the same specific operation type as the continuous state is recognized. When it is determined that the same specific operation type as the continuous state has not been recognized, the determination unit 340 clears the continuous state and clears the duration. When it is determined that the same specific operation type as that in the continuous state has been recognized, the determination unit 340 maintains the continuous state and determines whether or not the duration is equal to or greater than a predetermined duration threshold. If it is determined that the duration is equal to or longer than the duration threshold, it is determined that a continuous housing operation has been performed. Note that the determination unit 340 may use the number of times that the same specific operation type is recognized in place of the duration, and determine whether or not a continuous chassis operation has been performed based on the threshold value.

  When it is determined that the continuous chassis operation has been performed, the determination unit 340 notifies the application execution unit 300 of the specific operation type and the operation amount stored in the continuous state. At this time, the determination unit 340 may notify the application execution unit 300 of the change amount of the pressing force as the operation amount. For example, the determination unit 340 stores the pressing force Fs when the specific operation type is recognized in the state where the continuous state is cleared as the reference pressing force, and then recognizes that the continuous housing operation has been performed. A value obtained by subtracting the reference pressing force from the pressing force Fs at that time is calculated as an operation amount, and the specific operation type and the operation amount are notified to the application execution unit 300. The application execution unit 300 performs processing according to the specific operation type and the operation amount.

  For example, when the specific operation type indicates a scroll position on the screen, the application execution unit 300 determines the screen scroll position based on the operation amount. When the specific operation type indicates scrolling in a specific direction on the screen, the application execution unit 300 determines the scroll speed based on the operation amount. When the specific operation type indicates a change in the display size of a specific object on the screen, the application execution unit 300 determines the changed display size based on the operation amount. When the specific operation type indicates a change in volume, the application execution unit 300 determines the changed volume based on the operation amount. According to such an operation, the user can input the operation type by the position where the touch panel is gripped, and can input the operation amount by changing the gripping force.

  The cover panel 120 may be slightly curved in advance. For example, when the above-described operation OC and operation OD are used, a curved surface curved with the straight line L4 as a valley may be used. As a result, the user simply applies a force in the X direction to HC2, applies a force in the -X direction to HC3, and places the cover panel 120 in the curved pattern # 4 state without applying a downward force to HC1. be able to.

  Note that the housing 600 may extend in the Z direction at the peripheral edge of the cover panel 120 to support the force sensor 130, and the force sensor 130 may support the surface side of the cover panel 120. In this case, the signs of the measured value, the expected measurement value, and the difference value are opposite to those in the case where the four force sensors 130 described above support the back surface of the cover panel 120.

  According to the present embodiment, the user can cause the application execution unit 300 to execute a predetermined process by applying a force other than pressing on the surface of the cover panel 120 to the touch panel without providing a special switch on the touch panel. it can.

  When the present invention is applied to a touch pad, the touch pad does not require the display panel 110 and the display control unit 410 among the elements of the touch panel of the above-described embodiment. The touch pad having such a configuration can obtain the same effect as the touch panel of the above-described embodiment.

  The touch input device may include a cover panel 120 as a panel, or may include the display panel 110 or the like instead of the cover panel 120. The touch input device may include a display panel 110 or the like as a display unit.

The technique described above can also be expressed as follows.
(Expression 1)
A panel,
A plurality of force sensors respectively supporting a plurality of positions of the panel;
A housing that supports the plurality of force sensors;
Based on outputs of the plurality of force sensors, a plurality of measured values indicating forces applied to the plurality of force sensors are detected, respectively, and a pressing force indicating the pressing force is calculated based on the plurality of measured values, Based on the plurality of measured values and the plurality of positions, a pressing coordinate indicating the position of the pressing on the surface of the panel is calculated, and under the assumption that the pressing force is applied to the pressing coordinate, the pressing force, Based on the pressed coordinates and the plurality of positions, calculate a plurality of estimated values respectively indicating the forces applied to the plurality of force sensors, and based on the plurality of measured values and the plurality of estimated values, deform the panel An arithmetic unit that recognizes the state of
A touch input device comprising:
(Expression 2)
The calculation unit calculates a plurality of difference values respectively indicating differences between the plurality of measured values and the plurality of estimated values, and based on the plurality of difference values, whether the cause of the pressing force is the pressing Determining whether or not the cause of the pressing force is not the pressing, based on the sign of the plurality of difference values, to recognize the state of deformation of the panel,
The touch input device according to expression 1.
(Expression 3)
The calculation unit stores in advance related information indicating an association between a code condition indicating the sign of the plurality of difference values and the candidate for the state, and when it is determined that the cause of the pressing force is not the pressing, From related information, select a code condition that matches the calculated code of the plurality of difference values, and recognize a candidate corresponding to the selected code condition as the state,
The touch input device according to Expression 2.
(Expression 4)
When the calculation unit recognizes the state continuously, it recognizes the amount of change in the pressing force while the state is continuous.
The touch input device according to any one of expressions 1 to 3.
(Expression 5)
The arithmetic unit, when recognizing the state, executes a function previously associated with the state,
The touch input device according to any one of expressions 1 to 4.
(Expression 6)
The arithmetic unit, when recognizing the state, determines an operation amount of the function based on the pressing force.
The touch input device according to expression 5.
(Expression 7)
The function is any one of the movement of the image output by the calculation unit, the change of the size of the image output by the calculation unit, and the change of the sound level output by the calculation unit.
The touch input device according to expression 5 or 6.

The above-described technique can be further expressed as follows.
(Expression 8)
The calculation unit determines whether any of the plurality of difference values is greater than a predetermined difference threshold, and determines that any of the plurality of difference values is greater than the difference threshold. If it is determined that the cause of the pressing force is not the pressing,
The touch input device according to expression 2 or 3.
(Expression 9)
The calculation unit calculates the plurality of estimated values by allocating the pressing force to the plurality of positions based on the pressing coordinates.
The touch input device according to any one of expressions 1 to 8.
(Expression 10)
The calculation unit calculates a total of the plurality of measured values as the pressing force, and when the pressing force is larger than a predetermined pressing force threshold, the coordinates of the plurality of force sensors in the panel and the plurality of pressing forces are calculated. The pressed coordinates are calculated based on the measured value.
The touch input device according to any one of expressions 1 to 9.
(Expression 11)
The surface of the panel is rectangular,
The plurality of force sensors are four force sensors,
The four force sensors are arranged corresponding to the four vertices on the back surface of the panel.
The touch input device according to any one of expressions 1 to 10.
(Expression 12)
Including a display area for displaying a screen based on an instruction from the arithmetic unit, the display area further comprising a display unit covered by the panel;
The panel is transparent to the display;
The pressed coordinates are represented by coordinates on the display area.
The touch input device according to any one of expressions 1 to 10.
(Expression 13)
When it is determined that the cause of the pressing force is the pressing, the arithmetic unit controls display at the pressing coordinates based on the pressing coordinates and the pressing force.
The touch input device according to expression 12.
(Expression 14)
When it is determined that the cause of the pressing force is not the pressing, the calculation unit moves the object displayed on the screen based on the state.
The touch input device according to expression 13.
(Expression 15)
The calculation unit determines a movement amount of the movement based on the pressing force.
The touch input device according to expression 14.
(Expression 16)
A voice output unit that outputs voice based on an instruction from the calculation unit;
When it is determined that the cause of the pressing force is not the pressing, the arithmetic unit changes the volume of the sound based on the state.
The touch input device according to any one of expressions 1 to 15.
(Expression 17)
When it is determined that the cause of the pressing force is the pressing, the calculation unit outputs the pressing coordinates and the pressing force,
When it is determined that the cause of the pressing force is not the pressing, the arithmetic unit outputs the state and the pressing force.
The touch input device according to any one of expressions 1 to 16.

  The present invention is not limited to the above-described embodiment. A person skilled in the art can make various additions and changes within the scope of the present invention.

  DESCRIPTION OF SYMBOLS 100: Panel part 110: Display panel 120: Cover panel 130: Force sensor 150: Base part 200, 200b: Signal calculation part 300: Application execution part 310: Input calculation part 330: Expected measurement value Calculation unit, 340: determination unit, 400: calculation unit, 410: display control unit, 420: initial load update unit, 500: signal conversion unit, 510: A / D conversion unit 600: housing

Claims (8)

A panel,
A plurality of force sensors respectively supporting a plurality of positions of the panel;
A housing that supports the plurality of force sensors;
Based on outputs of the plurality of force sensors, a plurality of measured values indicating forces applied to the plurality of force sensors are detected, respectively, and a pressing force indicating the pressing force is calculated based on the plurality of measured values, Based on the plurality of measured values and the plurality of positions, a pressing coordinate indicating the position of the pressing on the surface of the panel is calculated, and under the assumption that the pressing force is applied to the pressing coordinate, the pressing force, Based on the pressed coordinates and the plurality of positions, calculate a plurality of estimated values respectively indicating the forces applied to the plurality of force sensors, and based on the plurality of measured values and the plurality of estimated values, deform the panel An arithmetic unit that recognizes the state of
A touch input device comprising: The calculation unit calculates a plurality of difference values respectively indicating differences between the plurality of measured values and the plurality of estimated values, and based on the plurality of difference values, whether the cause of the pressing force is the pressing Determining whether or not the cause of the pressing force is not the pressing, based on the sign of the plurality of difference values, to recognize the state of deformation of the panel,
The touch input device according to claim 1. The calculation unit stores in advance related information indicating an association between a code condition indicating the sign of the plurality of difference values and the candidate for the state, and when it is determined that the cause of the pressing force is not the pressing, From related information, select a code condition that matches the calculated code of the plurality of difference values, and recognize a candidate corresponding to the selected code condition as the state,
The touch input device according to claim 2. When the calculation unit recognizes the state continuously, it recognizes the amount of change in the pressing force while the state is continuous.
The touch input device according to claim 1. The arithmetic unit, when recognizing the state, executes a function previously associated with the state,
The touch input device according to claim 1. The arithmetic unit, when recognizing the state, determines an operation amount of the function based on the pressing force.
The touch input device according to claim 5. The function includes any one of movement of an image output by the calculation unit, change of a size of an image output by the calculation unit, and change of a sound level output by the calculation unit.
The touch input device according to claim 5 or 6. Using a plurality of force sensors supported by a housing and supporting a plurality of positions of the panel, respectively, based on outputs of the plurality of force sensors, respectively, detecting a plurality of measured values indicating forces applied to the plurality of force sensors;
Calculating a pressing force indicating the pressing force based on the plurality of measured values; calculating a pressing coordinate indicating the position of the pressing on the surface of the panel based on the plurality of measured values and the plurality of positions;
Under the assumption that the pressing force is applied to the pressing coordinates, a plurality of estimated values respectively indicating the forces applied to the plurality of force sensors are calculated based on the pressing force, the pressing coordinates, and the plurality of positions. ,
Recognizing the deformation state of the panel based on the plurality of measured values and the plurality of estimated values;
An input detection method comprising:

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