JP2008059123A - Touch panel device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the rate of malfunction due to the influence of diffused external light rays by performing position detection by a simple method even when there is influence due to the diffused external light rays. <P>SOLUTION: A demodulator 5 performs processing to create a strength modulation signal by increasing the level(current value) of an oscillation signal to be output by a crystal oscillator 4 to a predetermined level. A multiplexer 2 selects LED 11 and 12 as the object of light emission, and outputs a strength modulation signal. The LED 11 and 12 emit the rays of light based on the strength modulation signal. Detectors 21 and 22 converts the received infrared beam into an electric signal, and outputs it. A band pass filter 6 makes the signal component of the frequency of the strength modulation signal pass from the electric signal. Then, the CPU 1 decides the presence/absence of the input operation from the display surface according to whether or not a significant signal has been input from the band pass filter 6 through an A/D converter 7. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a touch panel device, and more particularly to an optical touch panel device.

  A touch panel device is known as a position input device in which a contact position detection device is mounted on a display screen such as a CRT or LCD (liquid crystal display). If the touch panel device is used, an instruction can be given to the computer or information can be input by touching the touch panel with a finger or a dedicated pen. That is, the touch panel device is an input device that can input information by detecting coordinates of a position designated by a finger or the like using a display screen as a coordinate plane.

  In the touch panel device, the method for detecting the indicated position on the display screen includes a resistive film method for detecting the contact position of the conducting wire in the vertical direction and the horizontal direction, and an optical for detecting the blocking position of infrared rays in the vertical direction and the horizontal direction. A method (infrared ray blocking detection method) and the like are known. An optical touch panel device is used in ATMs, ticket vending machines, and the like because of its high transmittance, high reliability, and excellent environmental resistance. In either case, it is necessary to detect the indicated position on the display screen with high accuracy.

  FIG. 6 is a block diagram illustrating a configuration example of a touch panel device using an infrared ray blocking detection method. The touch panel device shown in FIG. 6 includes a CPU 1, a multiplexer 2, a multiplexer 3, and a display unit 10 such as a CRT.

  A plurality of LEDs (light emitting diodes) 11 are provided at regular intervals on one side in the vertical direction of the display screen of the display unit 10, and the same number of detectors 21 as the LEDs 11 are provided on opposite sides. In addition, a plurality of LEDs 12 are provided at regular intervals on one side in the horizontal direction of the display screen, and the same number of detectors 22 as the LEDs 12 are provided on opposite sides.

  The LED 11 emits an infrared beam at a predetermined cycle in the horizontal direction of the display screen toward the opposing detector 21, and the detector 21 receives the infrared beam. Further, the LED 12 emits an infrared beam at a predetermined cycle in the vertical direction of the display screen toward the opposing detector 22, and the detector 22 receives the infrared beam. In this case, each LED 11 provided in the vertical direction of the display screen is controlled so as to emit infrared beams by sequentially driving at predetermined time intervals. Each LED 12 provided in the horizontal direction of the display screen is controlled so as to emit an infrared beam by sequentially driving in a predetermined cycle. If the infrared beam is blocked by a light blocking object such as a finger or a pen and the detectors 21 and 22 cannot receive the infrared beam, the coordinates on the display screen corresponding to the detector that cannot receive the infrared beam are input. Detected as coordinates (touch points).

  The CPU 1 has a function of controlling the multiplexers 2 and 3. Further, the CPU 1 determines the presence / absence of a light shielding object based on the electrical signal output from the multiplexer 3, and detects coordinates on the display screen instructed by the light shielding object.

  The multiplexer 2 sequentially selects the LEDs 11 and 12 in a predetermined cycle, and outputs an input signal to the selected LEDs 11 and 12. In addition, the multiplexer 3 sequentially selects the detectors 21 and 22 that face the LEDs 11 and 12 selected by the multiplexer 2, and detects that the selected detectors 21 and 22 have received the infrared beam. The electrical signal is output to the CPU 1.

  In the touch panel device using the infrared ray blocking detection method, when disturbance light such as sunlight is irradiated, the light receiving element may be saturated by the infrared wavelength component of the disturbance light, and position detection may become impossible. For example, when an ATM or a ticket machine equipped with a touch panel device is installed outdoors, or when it is in an environment where it is easy for sunlight to enter the west, the position cannot be detected due to the influence of ambient light such as sunlight. It is easy to become.

  There has been proposed an optical touch panel that prevents the light receiving element from becoming saturated and undetectable due to the influence of the infrared wavelength component of disturbance light (see, for example, Patent Document 1). Patent Document 1 describes that a light receiving element output signal is obtained by using a modulated light beam, extracting a specific frequency modulated from a received signal, amplifying and demodulating it.

JP-A-5-94255 (paragraphs 0024-0029)

  However, in the method described in Patent Document 1, even when there is an influence due to disturbance light, by transmitting a modulated light beam from a light emitting element so that it can be detected and demodulated on the receiving side, Position detection is possible. However, an amplifier and a demodulator must be provided to process the modulated light beam, which complicates the configuration of the touch panel device and increases costs.

  Accordingly, an object of the present invention is to provide a touch panel device that can detect a position by a simple method even when there is an influence of disturbance light, and can reduce the rate of malfunction due to the influence of disturbance light.

  In the touch panel device according to the present invention, a plurality of X direction light emitting elements (for example, LEDs 12) are arranged in the X direction and a plurality of Y direction light emitting elements (for example, LEDs 11) are arranged in the Y direction on a part of the display unit. A plurality of X direction light receiving elements (for example, the detector 22) are arranged to face each of the plurality of X direction light emitting elements, and a plurality of Y direction light receiving elements (for example, the detector 21) are arranged in the plurality of Y direction light emitting elements. Electric signals output in response to receiving light from the X-direction light emitting elements arranged opposite to each other and facing the plurality of X-direction light receiving elements, and Y-direction light emission facing the plurality of Y-direction light receiving elements A touch panel device including detection means for detecting a touch position on a display unit based on an electric signal output in response to reception of light from an element, wherein the light emitted from a plurality of X-direction light emitting elements and Intensity modulation means (for example, crystal resonator 4 and modulator 5) that performs processing for applying intensity modulation to light emitted from the plurality of Y-direction light emitting elements at a predetermined frequency, and the plurality of X-direction light receiving elements receive light. Frequency component extraction means (for example, a band-pass filter) for extracting a component of a predetermined frequency from the electrical signal output in response to the signal and the electrical signal output in response to light reception by the plurality of Y-direction light receiving elements. For example, the CPU 1) is characterized in that the touch position is detected based on a predetermined frequency component extracted by the frequency component extraction means.

  For example, the intensity modulation means performs intensity modulation by outputting a drive signal based on an oscillation signal generated by a crystal oscillator to a plurality of X direction light emitting elements and a plurality of Y direction light emitting elements, and the frequency component extracting means A band-pass filter that passes a signal component in a frequency band including the frequency of.

  According to the present invention, when the intensity of disturbance light is high in the touch panel device, the presence or absence of an input operation is detected by receiving light whose intensity is modulated at a predetermined frequency and detecting a predetermined frequency component. Even so, the coordinate position can be detected, and the rate of malfunction due to the influence of ambient light can be reduced. Further, according to the present invention, it is possible to detect the presence or absence of an input operation without being affected by ambient light without providing an amplifier, a demodulator, or the like, thereby reducing the complexity of the touch panel device and the increase in cost. can do. Therefore, even if there is an influence of disturbance light, position detection can be performed with a simple method, and the rate of malfunction due to the influence of disturbance light can be reduced.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram illustrating a configuration example of a touch panel device according to the present invention. As shown in FIG. 1, the touch panel device includes a CPU 1, a multiplexer 2, a multiplexer 3, a crystal resonator 4, a modulator 5, a bandpass filter 6, an A / D converter 7, and a CRT. And a display unit 10.

  A plurality of LEDs 11 are provided at regular intervals on one side in the vertical direction (Y direction) of the display screen of the display unit 10, and the same number of detectors 21 as the LEDs 11 are provided on opposite sides. Each detector 21 is arranged so as to face each LED 11. In addition, a plurality of LEDs 12 are provided at regular intervals on one side of the display screen in the horizontal direction (X direction), and the same number of detectors 22 as the LEDs 12 are provided on opposite sides. Moreover, each detector 22 is arrange | positioned so that each LED12 may be opposed, respectively.

  The LEDs 11 and 12 are light emitting elements that convert electrical energy into light, and are, for example, infrared LEDs. Specifically, the LEDs 11 and 12 emit light based on an input signal from the multiplexer 2. The detectors 21 and 22 are light receiving elements that convert light into electric energy, and are, for example, phototransistors. Specifically, the detectors 21 and 22 receive the light emitted from the LEDs 11 and 12, convert them into electrical signals, and output them.

  Note that the LEDs 11 and 12 and the detectors 21 and 22 are provided in a peripheral portion (frame portion) of four sides in a case or the like in which the display unit 10 is stored.

  The LEDs 11 and 12 emit an infrared beam when an input signal is input from the multiplexer 2. In this embodiment, the LED 11 emits an infrared beam at a predetermined cycle in the horizontal direction of the display screen toward the opposing detector 21, and the detector 21 receives the infrared beam. Further, the LED 12 emits an infrared beam at a predetermined cycle in the vertical direction of the display screen toward the opposing detector 22, and the detector 22 receives the infrared beam. In this case, each LED 11 provided in the vertical direction of the display screen is controlled so as to emit infrared beams by sequentially driving at predetermined time intervals. Each LED 12 provided in the horizontal direction of the display screen is controlled so as to emit an infrared beam by sequentially driving in a predetermined cycle. If the infrared beam is blocked by a light-shielding object such as a finger or a pen and the detectors 21 and 22 cannot receive the infrared beam, the coordinates (touch) on the display screen corresponding to the light receiving element that cannot receive the infrared beam. Point) is detected.

  The CPU 1 operates according to a program and performs drive control of the LEDs 11 and 12 and the detectors 21 and 22. Specifically, the multiplexer 2 is controlled to select the LEDs 11 and 12 that output an input signal in order. Further, the CPU 1 controls the multiplexer 3 to sequentially select the detectors 21 and 22 that are light detection targets. Then, the CPU 1 determines the presence / absence of a light-shielding object (for example, a finger or a pen) on the display screen based on the signal from the bandpass filter 6 via the A / D converter 7 and is instructed by the light-shielding object. Detect coordinates on the display screen.

  The crystal resonator 4 is an element that generates a predetermined oscillation signal based on the self-resonance frequency. The crystal unit 4 generates a signal having a frequency of several MHz to several tens of MHz, for example.

  The modulator 5 performs processing for increasing the level (current value) of the oscillation signal output from the crystal unit 4 to a predetermined level. In this embodiment, causing the LEDs 11 and 12 to emit light based on the output of the modulator 5 in which the level of the oscillation signal output from the crystal resonator 4 is increased is referred to as intensity modulation. The output of the modulator 5 is also expressed as an intensity modulation signal.

  On the light receiving side, by confirming whether or not the oscillation signal component can be extracted from the detection signals from the detectors 21 and 22 by using the band pass filter 6, the signals received by the detectors 21 and 22 are properly transmitted from the LEDs 11 and 12. It is possible to confirm whether the light has been emitted or is due to the influence of ambient light.

  The multiplexer 2 sequentially selects the LEDs 11 and 12 that emit infrared beams in a predetermined cycle in accordance with the control of the CPU 1. Further, the multiplexer 2 causes the LEDs 11 and 12 to emit infrared beams by outputting the input signals whose intensity is modulated by the modulator 5 to the selected LEDs 11 and 12. Further, the multiplexer 3 sequentially selects the detectors 21 and 22 facing the LEDs 11 and 12 selected by the multiplexer 2 according to the control of the CPU 1. Further, the multiplexer 3 outputs the detection signals (electric signals) of the selected detectors 21 and 22 to the band pass filter 6.

  FIG. 2 is an explanatory diagram for explaining an input signal and an intensity modulation signal. FIG. 2A is an explanatory diagram illustrating an example of a signal (a signal when it is assumed that no modulation is performed) for causing the LEDs 11 and 12 to emit light.

  FIG. 2B is an explanatory diagram showing an intensity modulation signal. In this embodiment, the modulator 5 converts an oscillation signal having a frequency of several MHz to several tens of MHz into an intensity modulation signal. When an intensity modulation signal as shown in FIG. 2B is input, the LEDs 11 and 12 emit light with an intensity substantially proportional to the level of the intensity modulation signal. That is, the LEDs 11 and 12 direct an infrared beam having an intensity corresponding to the level (current value) of the intensity modulation signal (see FIG. 2B) input via the multiplexer 2 toward the opposing detectors 21 and 22. Emits light.

  The detectors 21 and 22 receive the infrared beam, convert it into an electrical signal, and output it to the multiplexer 3. The detectors 21 and 22 output an electric signal having an amplitude corresponding to the amount (intensity) of the infrared beam received from the LEDs 11 and 12. In this case, when light is emitted by the LEDs 11 and 12 based on the intensity modulation signal, the detectors 21 and 22 receive the intensity-modulated infrared beam, and as shown in FIG. An electric signal having a waveform (similar to the waveform shown in FIG. 2B) is output.

  When there is no blocking object on the display screen (that is, when an input operation using a finger or the like is not performed), an electric signal corresponding to the intensity-modulated input signal is output. On the other hand, when there is a blocking object on the display screen (that is, when an input operation using a finger or the like is performed), the infrared beam emitted from the LEDs 11 and 12 is blocked, so No electrical signal is output from 22.

  Here, when the detectors 21 and 22 receive disturbance light such as the solar sun, an electric signal corresponding to the intensity and frequency of the received disturbance light is output. Therefore, the detectors 21 and 22 detect an infrared signal and output an electrical signal regardless of whether or not there is a blocking object on the display screen (whether or not an input operation using a finger or the like is performed). As a result, there is a possibility that the presence or absence of an input operation cannot be correctly recognized.

  In this embodiment, since an infrared beam based on an intensity modulation signal is emitted from the LEDs 11 and 12, whether or not the detected infrared signal is an intensity-modulated signal even when there is an influence of disturbance light. If it is confirmed on the light receiving side, it can be confirmed whether or not the infrared signal is normally emitted from the LEDs 11 and 12. Therefore, even when there is an influence of disturbance light, it is possible to correctly recognize the presence or absence of an input operation from the touch panel. In general, the frequency of ambient light such as the western sun is low.

  The bandpass filter 6 is a filter circuit that extracts a specific frequency component of the electric signal. The band pass filter 6 extracts a signal component in a frequency band including the frequency of the intensity modulation signal from the electrical signal output by the multiplexer 3 and outputs the signal component to the A / D converter 7. The AD converter 7 converts the output of the bandpass filter 6 into a digital signal and outputs it to the CPU 1.

  FIG. 3 is an explanatory diagram illustrating an example of frequency characteristics of the bandpass filter. As shown in FIG. 3, the bandpass filter 6 has a frequency characteristic such that the frequency of the intensity modulation signal is included in the passband.

  When there is no obstruction, the detectors 21 and 22 output the electrical signals shown in FIG. It is possible to extract a signal component in the included frequency band (a signal component having a frequency of several MHz to several tens of MHz (a signal component in the same band as the oscillation signal)). If there is a blocking object, the LED 11, 12 and the detectors 21, 22 are blocked, so that no electrical signal is output from the detectors 21, 22, and the intensity modulation signal even if the bandpass filter 6 is used. The signal component of the frequency is not extracted.

  In addition, when disturbance light is present and there is no blocking object, the electrical signals shown in FIG. 2C are also output by the detectors 21 and 22, so that the output of the detectors 21 and 22 is output by the bandpass filter 6. The signal component of the frequency of the intensity modulation signal can be extracted from the signal. On the other hand, when there is a blocking object, an electrical signal can be output from the detectors 21 and 22 even though the LED 11 and 12 and the detectors 21 and 22 are blocked by the influence of ambient light. . However, when an infrared signal is detected due to the influence of disturbance light, the detectors 21 and 22 output electrical signals that are not subjected to intensity modulation, so even if the bandpass filter 6 is used. The signal component of the frequency of the intensity modulation signal is not extracted. Therefore, the detection signal of the input operation can be accurately transmitted to the CPU 1 even when there is an influence of disturbance light depending on whether or not the signal component of the frequency of the intensity modulation signal is output by the band pass filter 6. .

  The CPU 1 determines the coordinates on the display screen corresponding to the detectors 21 and 22 that did not output the signal component in the frequency band of the intensity modulation based on the electrical signal output from the bandpass filter 6 and A / D converted. By detecting, input coordinates using a finger or the like on the touch panel can be specified.

  Next, the operation will be described. FIG. 4 is a block diagram showing a more detailed configuration of the touch panel device shown in FIG. As shown in FIG. 4, the multiplexer 2 has a configuration in which the LEDs 11 and 12 are selected and switched, and an input signal after intensity modulation is output to one of the LEDs 11 and 12. Further, the multiplexer 3 has a configuration in which the detectors 21 and 22 are selected and switched, and the detection signals of any of the detectors 21 and 22 are output to the bandpass filter 6.

  FIG. 5 is a flowchart illustrating an example of touch panel input detection processing executed by the CPU 1. In this embodiment, the CPU 1 constantly monitors the presence or absence of an input operation from the touch panel by repeatedly executing the input detection process shown in FIG.

  In the input detection process, the CPU 1 first sets 1 to a predetermined variable i (step S11). The variable i is a variable that indicates what number of LEDs 11 and 12 and the detectors 21 and 22 are currently being processed.

  Next, the CPU 1 causes the multiplexer 2 to select the i-th LEDs 11 and 12 and causes the multiplexer 3 to select the i-th detectors 21 and 22 based on the set value of the variable i (step S12). Then, the multiplexer 2 selects the i-th LEDs 11 and 12 and switches the connection in accordance with an instruction from the CPU 1. Further, the multiplexer 3 selects the i-th detectors 21 and 22 (detectors arranged at positions facing the i-th LED) and switches the connection in accordance with an instruction from the CPU 1. Then, the intensity-modulated input signal is input to the LEDs 11 and 12 selected by the multiplexer 2, and an infrared beam is emitted from the LEDs 11 and 12.

  If step S12 is executed immediately after step S11 is executed, the variable i is set to the value 1, so that the first LEDs 11 and 12 and the first detectors 21 and 22 are selected. The In this embodiment, as the first LED, the LED 11 arranged on the uppermost side among the LEDs 11 arranged on the vertical side of the display screen of the display unit 10 is selected. Thereafter, as the value of the variable i is incremented by 1, the LEDs 11 arranged on the vertical side are selected one by one in order from the upper side. When all the LEDs 11 arranged on the vertical side of the display screen have been selected, the LEDs 12 arranged on the horizontal side of the display screen are then left as the value of the variable i is incremented by one. It is assumed that one by one is selected in order.

  In this embodiment, as the first detector, the detector 21 arranged on the uppermost side among the detectors 21 arranged on the vertical side of the display screen (at a position facing the first LED 11). It is assumed that the detector) is selected. Thereafter, as the value of the variable i is incremented by 1, the detectors 21 arranged on the vertical sides are selected one by one in order from the upper side. When all the detectors 21 arranged on the vertical side of the display screen have been selected, the next detector 22 arranged on the horizontal side of the display screen increments the value of the variable i by one. It is assumed that one by one is selected in order from the left side as it is done.

  Note that the order of selection of the LEDs 11 and 12 and the detectors 21 and 22 described above is an example, and other selection orders such as selecting the LEDs 12 and the detector 22 from the right side may be followed.

  Next, the CPU 1 checks whether or not the selected detectors 21 and 22 have received the infrared beam (step S13). Specifically, the CPU 1 determines whether or not a signal component is input from the band pass filter 6. In this case, if the input operation such as touching the touch panel with a finger or the like is not performed, the selected detectors 21 and 22 should receive the infrared beam emitted from the LEDs 11 and 12. The signal component (significant signal) of the frequency of the intensity modulation signal is input from the band pass filter 6 through the AD converter 7. If the input operation is performed, the selected detectors 21 and 22 and the LEDs 11 and 12 should be cut off and the infrared beam should not be received, so the CPU 1 passes the band-pass filter 6 through the AD converter 7. Therefore, a significant signal cannot be input.

  On the other hand, when there is an influence of disturbance light, the detectors 21 and 22 may receive infrared rays even if an input operation is performed. However, since the received infrared signal does not include the signal component of the frequency of the enhanced modulation signal, the CPU 1 cannot input a significant signal from the bandpass filter 6. Therefore, in step S13, the CPU 1 does not input a significant signal if an input operation is performed regardless of the influence of ambient light, and inputs a significant signal if no input operation is performed. Will do.

  When the signal component is input from the bandpass filter 6 (that is, when the input operation is not performed), the CPU 1 proceeds to step S15 as it is. When no signal component is input from the bandpass filter 6 (that is, when an input operation is performed), the CPU 1 detects input coordinates corresponding to the selected LEDs 11 and 12 and the detectors 21 and 22 ( Step S14).

  In this embodiment, for example, coordinates X = 0, 1, 2,... Are assigned in advance from the upper side to the LEDs 11 and the detectors 21 arranged in the vertical direction of the display screen. Therefore, when the LED 1 and the detector 21 arranged in the vertical direction are selected and the signal is not input from the bandpass filter 6, the CPU 1 detects the coordinate value of the corresponding X coordinate. Further, for example, coordinates Y = 0, 1, 2,... Are assigned in advance from the left side to the LEDs 12 and the detectors 22 arranged in the horizontal direction of the display screen. Therefore, when the LED 1 and the detector 22 arranged in the vertical direction are selected, the CPU 1 detects the coordinate value of the corresponding Y coordinate when no signal is input from the band pass filter 6.

  Next, the CPU 1 adds 1 to the value of the variable i (step S15), and determines whether or not the value of the variable i is larger than the total number n of LEDs 11 and 12 (also the total number of detectors 21 and 22). (Step S16). If the value of the variable i is less than or equal to n, it means that the processing has not been completed for all the LEDs 11 and 12 and the detectors 21 and 22, and therefore, the processing after step S12 is repeatedly executed. If the value of the variable i is larger than n, it means that the process has been completed for all the LEDs 11 and 12 and the detectors 21 and 22, and therefore the process returns to step S11.

  As described above, according to the present embodiment, since the presence or absence of a blocking object is detected by detecting the signal component of the frequency of the intensity modulation signal on the light receiving side, the disturbance light has a high intensity. However, the coordinate position can be detected, and the rate of malfunction due to the influence of ambient light can be reduced. Further, according to this embodiment, light is emitted based on an electric signal (intensity modulation signal) obtained by performing level conversion processing on the oscillation signal of the crystal unit 4. Then, the presence or absence of an input operation is detected by confirming whether or not the signal component of the intensity modulation signal can be extracted using the bandpass filter 6 on the light receiving side. Therefore, the presence or absence of an input operation can be detected without being affected by ambient light without providing an amplifier, a demodulator, or the like, and the touch panel device can be prevented from becoming complicated in configuration and cost. Therefore, even if there is an influence of disturbance light, position detection can be performed with a simple method, and the rate of malfunction due to the influence of disturbance light can be reduced.

  In this embodiment, the sequential selection method in which the LEDs 11 and 12 and the detectors 21 and 22 are sequentially selected is taken as an example. However, the LEDs 11 and 12 are caused to emit light at the same time, and the detection signals of the detectors 21 and 22 are simultaneously transmitted. The present invention can also be applied to a simultaneous method in which position detection is performed by inputting the signal into the input.

  The present invention can be suitably applied to a touch panel device using an optical system.

It is a block diagram which shows the structural example of the touchscreen apparatus by this invention. It is explanatory drawing for demonstrating an input signal and an intensity | strength modulation signal. It is explanatory drawing which shows the example of the frequency characteristic of a band pass filter. It is a block diagram which shows the more detailed structure of a touchscreen apparatus. It is a flowchart which shows an example of the input detection process of the touch panel which CPU performs. It is a block diagram which shows the structural example of the touchscreen apparatus by an infrared rays interruption | blocking detection system.

Explanation of symbols

1 CPU
2, 3 Multiplexer 4 Crystal resonator 5 Modulator 6 Band pass filter 7 A-D converter 10 Display unit 11, 12 LED
21, 22 detector

Claims (2)

A plurality of X direction light emitting elements are arranged in a part of the display unit in the X direction, a plurality of Y direction light emitting elements are arranged in the Y direction, and a plurality of X direction light receiving elements are arranged in each of the plurality of X direction light emitting elements. A plurality of Y direction light receiving elements are arranged to face each of the plurality of Y direction light emitting elements,
An electric signal output in response to light reception from the X direction light emitting element opposed to the plurality of X direction light receiving elements, and light reception from the Y direction light emitting element opposed to the plurality of Y direction light receiving elements. In a touch panel device provided with detection means for detecting a touch position on the display unit based on an electrical signal output according to
Intensity modulating means for performing processing for applying intensity modulation at a predetermined frequency to light emitted from the plurality of X direction light emitting elements and light emitted from the plurality of Y direction light emitting elements;
Frequency component extraction means for extracting a component of the predetermined frequency from the electrical signal output by the plurality of X direction light receiving elements in response to light reception and the electrical signal output by the plurality of Y direction light receiving elements in response to light reception. ,
The touch panel device, wherein the detection unit detects a touch position based on the component of the predetermined frequency extracted by the frequency component extraction unit. The intensity modulation means performs intensity modulation by outputting a drive signal based on the oscillation signal generated by the crystal resonator to the plurality of X direction light emitting elements and the plurality of Y direction light emitting elements,
The touch panel device according to claim 1, wherein the frequency component extraction unit includes a bandpass filter that allows a signal component in a frequency band including a predetermined frequency to pass therethrough.

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