JP2008287575A - Touch panel device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a touch panel device which has simple configuration and is satisfactory in a feeling of operation by eliminating difference in pressure-sensitive sensitivity due to depressing operation positions on a panel body. <P>SOLUTION: The touch panel device is equipped with: the panel body 12 composing a display screen; an operation position detection device for detecting an operating position with respect to the panel body 12; a longitudinal piezoelectric element 16 fixed to the peripheral edge of the panel body 12; a comparator 20 for discriminating the output of the piezoelectric element 16 due to a pressurizing force by the panel operation; a processor 22 for performing predetermined processing by detecting the operating position of the panel body 12 by the operation position detection device; and a D/A converter 24 as a threshold setting part for outputting a predetermined threshold to the comparator 20. The processor 22 performs processing to set a threshold to be set in the comparator 20 so that the threshold is inversely proportional to the distance from the piezoelectric element 16 to the operating position of the panel body 12 so as to offset the output fluctuation of the piezoelectric element 16 due to the operating position of the panel body 12. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a touch panel device that is provided on a display, an operation unit, or the like of various electronic devices and used as an input device.

  Conventionally, electronic devices having a touch panel function on a display surface have been widely used. This touch panel can be operated by touching the surface of the display, and there are several types of input methods. Among them, there is an optical touch panel that allows input even without contact. This is because each of the horizontal direction and the vertical direction is provided with a plurality of infrared LEDs and a plurality of phototransistors on the opposite side, and the input position on the panel is detected by blocking the optical path with a finger or the like, and a desired input operation is performed. Is what you do.

  However, the optical touch panel detects when the clothing such as the operator's tie hangs down on the panel surface or interrupts the pressing operation when the light path is interrupted against the operator's intention. Therefore, erroneous operations are likely to occur. This point also applies to a capacitive touch panel in which an operator detects an operation position by bringing a finger or the like closer to perform input processing.

  Therefore, the contact force at the time of operation is detected by a piezoelectric element or a force sensor, and when the operation pressure of a certain level or more is detected by the sensor, it is determined as a panel pressing operation, and optically detected panel pressing position information is input. There is a pressure-sensitive touch panel that judges information.

Further, as disclosed in Patent Document 1, when the operation panel is pressed, a pressing detection means such as a strain gauge that outputs a current corresponding to the pressing pressure, and the current output of each pressing detection means. A coordinate calculation means for calculating a coordinate input signal on the plane corresponding to the pressed position on the operation panel, and a direction perpendicular to the two-dimensional plane corresponding to the pressure at the pressed position from the current output of each pressed detection means There has also been proposed a touch panel provided with second coordinate calculation means for calculating a further coordinate input signal.
JP 2005-78194 A

  However, in a pressure-sensitive touch panel, the output level of the sensor differs depending on the operator's panel pressing position and the mounting position of the force sensor, etc., and the pressure sensitivity on the entire panel operation surface is not constant. There was a problem that the sensitivity to the operation at a remote position was poor. In addition, in the case of the touch panel having the structure disclosed in Patent Document 1, since the pressed position is calculated from the signal obtained by the pressed detection means, there is a problem that the position detection accuracy is poor and the circuit is complicated.

  The present invention has been made in view of the problems of the background art described above, and has an object to provide a touch panel device having a simple operation, eliminating a difference in pressure-sensitive sensitivity depending on a position on a panel body, and having a good operation feeling. To do.

  The present invention relates to a panel body constituting a display screen, an operation position detection device for detecting an operation position with respect to the panel body, a long piezoelectric element fixed to the periphery of the panel body, and a pressing force by the panel operation. A comparator for discriminating the output of the piezoelectric element caused by the operation, a processing device for detecting the operation position of the panel body by the operation position detection device and performing a predetermined process, and a threshold setting for outputting a predetermined threshold to the comparator A touch panel device that processes the threshold value set in the comparator or the amplification factor of the output of the piezoelectric element so as to reduce the influence of the output fluctuation of the piezoelectric element due to the operation position of the panel body. It is.

  The processing device performs processing for setting a threshold value set in the comparator so as to be inversely proportional to a distance from the piezoelectric element to an operation position of the panel body.

  Alternatively, the processing device performs a process of setting an amplification factor set in a programmable gain amplifier that amplifies the output of the piezoelectric element so as to be proportional to a distance from the piezoelectric element to the operation position of the panel body. is there.

  Alternatively, the processing device compares the output of the A / D-converted piezoelectric element with a digital tile threshold set by a CPU or the like so as to be inversely proportional to the distance from the piezoelectric element to the operation position of the panel body. The process which performs is performed.

  A frame is attached to the peripheral edge of the panel body, and the operation position detecting device is provided along a light emitting element array provided along two mutually intersecting sides of the frame and a frame facing the light emitting element array. It is a light receiving element array.

  The touch panel device according to the present invention performs processing so as to cancel the variation in the output signal of the piezoelectric element depending on the operation position when detecting the operation on the panel body by the piezoelectric element, and is uniform regardless of the operation position on the panel body. A feeling of operation can be obtained. Furthermore, by making a difference in pressure sensitivity depending on the position on the panel body, the input operation can be made more reliable, or a touch panel device with higher functionality can be obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 and 2 show a first embodiment of the present invention. A touch panel device 10 according to this embodiment is used for an operation panel of a car navigation device, an ATM, a ticket machine, and other various electronic devices. Used as an input device. The touch panel device 10 includes a rectangular panel body 12 such as a transparent resin substrate or a glass substrate, and a frame 14 that houses the panel body 12.

  On two adjacent sides 14a and 14b of the frame 14, an LED array (not shown) as an operation position detection device is arranged, and emits light in the direction indicated by the arrow in the panel body 12 in FIG. On the two sides 14c and 14d facing the sides 14a and 14b, a phototransistor array (not shown) as an operation position detecting device for detecting the light of each element of the LED array facing each other is arranged.

  In the panel body 12, a long piezoelectric element 16 is fixed to the opposite sides 14 a and 14 c of the frame 14 along the periphery of the back surface thereof. The length of the piezoelectric element 16 may be, for example, ½ or more of the length of one side of the frame 14.

  As shown in FIG. 2, the piezoelectric element 16 of the touch panel device 10 has an output signal of the piezoelectric element 16 connected to an amplifier 18, and a signal amplified by the amplifier 18 is input to a comparator 20. A signal for setting a threshold value is input to the comparator 20 from the CPU 22 via a D / A converter 24 that is a threshold value setting unit. Each position signal in the X and Y directions of the panel body 12 from the phototransistor of the touch panel device 10 is input to the CPU 22.

  Next, the pressing operation position detection process of the touch panel device 10 of this embodiment will be described below. First, when the operator presses the panel body 12, the phototransistor output corresponding to the press operation position changes, and the CPU 22 determines the press operation position from the phototransistor output change positions of the frames 14c and 14d.

  At the same time, the outputs of the pair of piezoelectric elements 16 are input to the comparator 20 via the amplifier 18. A variable threshold value from the D / A converter 24 is input to the threshold value of the comparator 20. The adjustment variation of the threshold value of the comparator 20 is changed by the variable rule set by the CPU 22 judging the pressing operation position information and simulating in advance. For example, the threshold value may be adjusted by decreasing the threshold value as the output of the piezoelectric element 16 located farther from the piezoelectric element 16 or lowering the threshold stepwise so as to be proportional to the distance from the piezoelectric element 16. The information for making variable is recorded in a storage element (not shown) as a data table or a calculation formula based on a prior simulation, and is processed by the CPU 22 by a predetermined program.

  When the output of the comparator 20 becomes active due to the output from the piezoelectric element 16, the operation position information from the phototransistor at that time is a correct input operation, and the CPU 22 performs a predetermined operation based on the position information of the input signal. An operation signal is output to perform a predetermined processing operation of the electronic device. Further, when the output of the comparator 20 is not activated even though the operation position information is input from the phototransistor, there is no or insufficient pressing operation on the panel body 12. The CPU 22 does not output an operation signal.

  According to this embodiment, the variation in the output signal of the piezoelectric element 16 due to the pressing operation position on the panel body 12 is adjusted, and the input operation can be performed with a uniform operation feeling regardless of the operation position on the panel body 12. Is something that can be done. Further, depending on the operation position of the panel body 12, depending on the importance of the operation and the type of operation, the pressure sensitivity is intentionally varied to ensure the input operation or to have a complicated and highly functional specification. You can also.

  Next, a second embodiment of the touch panel device of the present invention will be described with reference to FIG. Here, the same members as those in the above embodiment are denoted by the same reference numerals, and description thereof is omitted. The touch panel device 30 of this embodiment uses a programmable gain amplifier (PGA) 32 having a variable amplification factor, and changes the amplification factor of the PGA 32 to which the output of the piezoelectric element 16 is input depending on the pressing operation position in the panel body 12. Is. The adjustment of the amplification factor of the PGA 32 is performed by controlling the increase in the amplification factor of the output of the piezoelectric element 16 as the pressing operation position is farther from the piezoelectric element 16 based on the pressing operation position information by the phototransistor. That is, the setting of the amplification factor may be an amplification factor proportional to the distance of the pressing operation position information from the piezoelectric element 16 or a stepwise amplification factor having a proportional tendency. In this case, the threshold value by the reference voltage 25 of the threshold value setting unit input to the comparator 20 is fixed.

  In the case of this embodiment, the output of the piezoelectric element 16 is adjusted according to the pressing operation position, and if the pressing operation is the same, the output from the PGA 32 of the piezoelectric element 16 becomes an output of the same level, and a certain threshold value is set. The pressing operation can be determined with.

  Next, a third embodiment of the touch panel device of the present invention will be described with reference to FIG. Here, the same members as those in the above embodiment are denoted by the same reference numerals, and description thereof is omitted. The touch panel device 34 of this embodiment converts a value obtained by amplifying the output of the piezoelectric element 16 into a digital signal by the A / D converter 38 and compares it with a value obtained by digitally adjusting the threshold value in the CPU 36. The operation is determined. In this case, the CPU 36 adjusts the threshold value in the same manner as in the first embodiment, and records the adjustment value in the storage element as a data table or a calculation formula.

  According to this embodiment, the same effect as the above embodiment can be obtained, the circuit can be simplified by digital processing, and versatility is high.

  The touch panel device of the present invention is not limited to the above-described embodiment, and can be used for a capacitive touch panel device in which the operation position detection device detects a change in capacitance. Further, the number of piezoelectric elements may be one as long as the process can reduce the influence of the output fluctuation of the piezoelectric element due to the operation position. Further, the type of comparator and the type of electronic device to be attached are not limited.

It is the top view (a), AA sectional drawing (b), and rear view (c) of the touch panel apparatus of 1st embodiment of this invention. It is a block diagram of a press detection discrimination circuit of the touch panel device of the first embodiment of the present invention. It is a block diagram of the press detection discrimination circuit of the touch panel device of the second embodiment of the present invention. It is a block diagram of the press detection discrimination | determination circuit of the touchscreen apparatus of 3rd embodiment of this invention.

Explanation of symbols

10 Touch Panel Device 12 Panel Body 14 Frame 16 Piezoelectric Element 18 Amplifier 20 Comparator 22 CPU
24 D / A converter

Claims (5)

  A panel body constituting a display screen, an operation position detection device for detecting an operation position with respect to the panel body, a long piezoelectric element fixed to the periphery of the panel body, and the pressure caused by the panel operation A comparator for discriminating an output of the piezoelectric element; a processing device for detecting the operation position of the panel body by the operation position detection device; and a threshold setting unit for outputting a predetermined threshold to the comparator. The processing device processes the threshold value set in the comparator or the amplification factor of the output of the piezoelectric element so as to reduce the influence of the output fluctuation of the piezoelectric element due to the operation position of the panel body. apparatus.   The touch panel device according to claim 1, wherein the processing device performs processing for setting a threshold value set in the comparator so as to be inversely proportional to a distance from the piezoelectric element to an operation position of the panel body.   The processing device performs a process of setting an amplification factor set in a programmable gain amplifier that amplifies the output of the piezoelectric element so as to be proportional to a distance from the piezoelectric element to an operation position of the panel body. Touch panel device.   The processing apparatus performs a process of comparing the output of the A / D converted piezoelectric element with a digitized threshold value set to be inversely proportional to the distance from the piezoelectric element to the operation position of the panel body. Item 10. A touch panel device according to Item 1. A frame is attached to the peripheral edge of the panel body, and the operation position detecting device is provided along a light emitting element array provided along two mutually intersecting sides of the frame and a frame facing the light emitting element array. The touch panel device according to claim 1, wherein the touch panel device is a light receiving element array.

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