JP6925741B2 - Touch panel device - Google Patents

Description

The present invention relates to a touch panel device that detects an operation position such as a user's finger in combination with a display screen.

Conventionally, there has been known a portable terminal device that changes the calibration method depending on the presence or absence of finger detection (see, for example, Patent Document 1). In this mobile terminal device, the presence or absence of finger detection is determined immediately after activation, and if finger is detected, calibration is performed once, and if there is a capacity change detection in the reverse direction, finger is detected. When the capacity change detection in the reverse direction disappears, the normal touch detection operation is started.

Japanese Unexamined Patent Publication No. 2015-11497

In an actual capacitance type touch panel device, there is a peripheral region where the capacitance increases around the position touched by a finger, and a filter that corrects (cancels) the capacitance in this peripheral region may be used. ..

FIG. 4 is an explanatory diagram when a filter that cancels the capacitance in the peripheral region is used. The example shown in FIG. 4 shows the measured value of the capacitance when one point of the touch panel is touched with a finger, and FIG. 4 (A) shows the measured value when the filter is not used in FIG. 4 (B). 4 (C) shows the capacitance after passing through the filter having the filter characteristics shown in FIG. 4 (B) with respect to the capacitance shown in FIG. 4 (A). There is.

As shown in FIG. 4A, when a point on the touch panel is touched with a finger, a phenomenon in which the capacitance increases in the peripheral region is observed (the portion indicated by a). On the other hand, when canceling the increased capacitance in this peripheral region with a filter, if the filter characteristics are set too strong as shown in FIG. 4 (B), the peripheral region is shown in FIG. 4 (C). Capacitance may change convexly in the opposite direction in the region (more precisely, around it).

When such a filter is used, if the user calibrates while touching the touch panel, the capacitance that has changed convexly in the opposite direction will be further inverted, so the detection sensitivity has been increased. When the touch panel is used in the state, there is a problem that the convex portion is erroneously detected even though the user does not actually touch the touch panel. Such erroneous detection of the convex portion cannot be solved by the method of Patent Document 1 described above.

The present invention was created in view of these points, and an object of the present invention is to correct the capacitance around the contact position and perform calibration regardless of the presence or absence of contact with a finger or the like. The purpose is to provide a touch panel device capable of providing a touch panel device capable of providing a touch panel device.

In order to solve the above-mentioned problems, the touch panel device of the present invention is a touch panel device in which a capacitance type touch panel is arranged on the surface of the display screen of the display device, and a plurality of electrodes arranged so as to intersect each other. When the user touches a part of the touch panel with a finger, a capacitance detecting means for detecting the capacitance between the touch panel having the above and a pair of electrodes intersecting on the touch panel corresponding to each intersection position. The user touches with a finger based on the filtering means that performs the filtering process that reduces the increasing capacitance in the surrounding area and the capacitance that has been detected and filtered by the capacitance detecting means. The position detecting means for detecting the position on the touch panel and the capacitance which is the reference of the detection operation by the capacitance detecting means are actually statically set by the capacitance detecting means prior to the position detecting operation by the position detecting means. It is equipped with a calibration means that executes a calibration that is set by detecting the capacitance, and the calibration means changes the capacitance when filtering is performed after the calibration is performed and when it is not performed. The presence or absence is judged, and if there is a fluctuation, the calibration is executed again.

In particular, the above-mentioned calibration means acquires two types of capacitance according to the presence or absence of filtering with respect to the capacitance detected by the capacitance detecting means, and uses these two types of capacitance. Based on this, the presence or absence of fluctuation in capacitance is determined. In addition, by filtering the capacitance detected by the capacitance detecting means when the user touches a part of the touch panel with a finger, the position where the user touches the touch panel in the peripheral area. The capacitance of the opposite polarity to the capacitance corresponding to the above appears.

When a part of the touch panel is touched with a finger, the capacitance increases in the region around the contact position of the finger. When the filtering process is performed to reduce (cancel) the increased capacitance, a capacitance having a polarity opposite to the increased capacitance is generated in a specific region near the peripheral region. If calibration is performed while touching a part of the touch panel, the capacitance after that will be detected based on the capacitance of the opposite polarity, so the filter processing can be switched on / off. By observing the fluctuation of the capacitance based on the capacitance of the opposite polarity of the lever, it is possible to know that the calibration was performed while touching a part of the touch panel, and the calibration can be redone. can. Therefore, even when the capacitance around the contact position is corrected by the filtering process, correct calibration can be performed regardless of the presence or absence of contact with a finger or the like.

Further, the above-mentioned filtering means can be set to a strength that reduces the capacitance that increases or decreases in the peripheral region, and the capacitance of the calibration means can be set depending on whether the filtering means is performed or not. When determining the presence or absence of fluctuation, it is desirable to set the degree of reduction to a strong value. The capacitance of opposite polarity generated in a specific region by the filtering process increases as the degree of setting of the filtering processing increases. Therefore, by increasing the degree of setting, the finger contact at the time of calibration is determined more reliably. It becomes possible to do.

It is a figure which shows the structure of the vehicle-mounted device of one Embodiment. It is a figure which shows the structure of the touch panel apparatus which is composed of a touch panel and a touch panel control unit. It is a flow chart which shows the operation procedure of the calibration performed in the touch panel apparatus. It is explanatory drawing in the case of using the filter which cancels a capacitance in a peripheral region.

Hereinafter, an in-vehicle device according to an embodiment to which the touch panel device of the present invention is applied will be described with reference to the drawings.

FIG. 1 is a diagram showing a configuration of an in-vehicle device according to an embodiment. As shown in FIG. 1, the in-vehicle device 1 includes a navigation processing unit 10, an AM radio tuner 14, an FM radio tuner 16, an AV processing unit 18, a display processing unit 20, a display device 22, a touch panel 30, a touch panel control unit 32, and an operation. It includes a unit 34, an input processing unit 36, a digital-to-analog converter (D / A) 40, a speaker 42, and a control unit 50.

The navigation processing unit 10 is used together with the GPS device 12 for detecting the position of the own vehicle, and uses map data to perform a navigation operation for guiding the traveling of the vehicle on which the in-vehicle device 1 is mounted. The AM radio tuner 14 receives an AM broadcast program and performs a process of reproducing audio corresponding to the program content. The FM radio tuner 16 receives an FM broadcast program and performs a process of reproducing audio corresponding to the program content. The AV processing unit 18 performs a process of reading and playing back music data and video data that have been compressed and stored in a hard disk device or the like (not shown).

The display processing unit 20 outputs video signals for displaying various operation screens, input screens, etc., displays these screens on the display device 22, and displays the video screens, etc. reproduced by the AV processing unit 18. Is output and this screen is displayed on the display device 22. The display device 22 is arranged in front of the center of the driver's seat and the passenger seat, and is configured by using a liquid crystal display (LCD).

The touch panel 30 is arranged on the surface of the display screen of the display device 22. The touch panel control unit 32 performs the control necessary for performing position detection using the touch panel 30. The touch panel 30 and the touch panel control unit 32 constitute a touch panel device that detects a position by a capacitance method. When various operation screens and input screens are displayed on the display device 22, the user directly points to a part of these operation screens and input screens with a finger or the like to select display items on the operation screen or input screen. In order to enable such an operation using the operation screen and the input screen, a touch panel 30 for detecting the position of the pointed finger or the like is provided. The details of the touch panel control unit 32 will be described later.

The operation unit 34 is for receiving an operation by the user on the in-vehicle device 1, and includes various operation keys, operation switches, operation knobs, and the like arranged around the display device 22. The input processing unit 36 monitors the operation unit 34 and determines the operation content thereof.

The digital-to-analog converter 40 converts the audio data and music data generated by the processing of the navigation processing unit 10, the AM radio tuner 14, the FM radio tuner 16, and the AV processing unit 18 into analog audio signals to be a speaker. Output from 42. The control unit 50 is for controlling the entire in-vehicle device 1, and is realized by executing a predetermined program stored in a ROM, RAM, or the like on the CPU. Each configuration of the vehicle-mounted device 1 described above is housed in the same housing except for the speaker 42.

FIG. 2 is a diagram showing a configuration of a touch panel device including a touch panel 30 and a touch panel control unit 32.

The touch panel 30 has a detection region that covers the entire display screen of the display device 22, and a plurality of first electrodes 30A extending along the X-axis direction (horizontal direction) of the detection region, and a Y-axis. It has a plurality of second electrodes 30B extending along a direction (vertical direction).

The touch panel control unit 32 includes a capacitance detection unit 100, a filter processing unit 102, a calibration processing unit 104, and a position detection unit 106.

The capacitance detection unit 100 detects (measures) the capacitance between each of the first electrodes 30A and each of the second electrodes 30B included in the touch panel 30. Specifically, the capacitance detection unit 100 detects the capacitances of the pair of electrodes 30A and 30B intersecting on the touch panel 30 corresponding to the respective intersection positions.

The filter processing unit 102 performs a filter process that reduces (cancels) the increasing capacitance in the peripheral region centered on the position touched by the finger. For example, a filter process using the filter characteristics shown in FIG. 4B is performed to reduce the capacitance in the peripheral region around the position touched by the finger. Assuming that the capacitance on the plus side increases by touching with a finger, this filtering process is equivalent to adding (superimposing) the capacitance on the minus side, and the capacitance on the minus side is If it is too large, as shown in FIG. 4C, the capacitance having the opposite polarity partially protrudes to the negative side.

The position detection unit 106 detects the position on the touch panel touched by the user with a finger based on the capacitance detected by the capacitance detection unit 100 and filtered by the filter processing unit 102. .. As shown in FIG. 4C, the capacitance at each intersection of the first electrode 30A and the second electrode 30B of the touch panel 30 increases at the position touched by the user, and thus the increased capacitance. By determining the capacity using a predetermined threshold value, it is possible to specify the position touched by the user's finger.

The calibration processing unit 104 actually detects the capacitance, which is the reference of the detection operation by the capacitance detection unit 100, by the capacitance detection unit 100 prior to the position detection operation by the position detection unit 106. Perform calibration for capacitance. In the present embodiment, the calibration performed with the user's finger touching a part of the touch panel 30 is invalid, and the calibration is repeated until there is no finger contact.

The capacitance detecting unit 100 corresponds to the capacitance detecting means, the filtering unit 102 corresponds to the filtering means, the position detecting unit 106 corresponds to the position detecting means, and the calibration processing unit 104 corresponds to the calibration means.

The in-vehicle device 1 of the present embodiment has such a configuration, and next, an operation of performing calibration in the touch panel device will be described.

FIG. 3 is a flow chart showing an operation procedure of calibration performed in the touch panel device. When the ignition key is turned on and the in-vehicle device 1 is activated, the capacitance detection unit 100 detects the capacitance of the touch panel 30 immediately after activation (step 100), and the calibration processing unit 104 performs calibration. (Step 102).

Next, the filter processing unit 102 sets the filter processing to off (disables the filter processing) (step 104), and the calibration processing unit 104 sets the filter processing to the positive side of the touch panel 30 corresponding to the state in which the filter processing is turned off. Acquire the capacitance of (step 106). The "capacitance on the plus side" means the capacitance on the increasing side when the user touches the touch panel 30 with a finger, and the capacitance on the decreasing side is excluded from the processing target. It is an intention.

Further, the filter processing unit 102 sets the filter processing to on (enables the filter processing) (step 108), and the calibration processing unit 104 is on the plus side of the touch panel 30 corresponding to the state in which the filter processing is turned on. Acquire the capacitance (step 110).

Next, the calibration processing unit 104 compares the capacitances acquired in steps 106 and 110 to see if the positive characteristic (capacitance) fluctuates in synchronization with the on / off of the filtering process. It is determined whether or not (step 112). When it fluctuates in synchronization, the calibration is performed while the user's finger is touching the touch panel 30, and the downwardly convex portion shown in FIG. 4C is inverted by the calibration on the plus side. This is the case where the capacitance on the positive side appears or disappears in synchronization with the on / off of the filtering process. In such a case, the calibration is not normally performed due to the touch of the user's finger, a positive judgment is made in the determination in step 112, and the process returns to step 102 after the calibration. Each operation of is repeated.

On the other hand, the case where the characteristic on the plus side does not fluctuate in synchronization with the on / off of the filter processing is the case where the entire characteristic shown in FIG. 4C does not appear because the user's finger does not touch the touch panel 30. This is the case where the capacitance on the positive side is not measured regardless of whether the filtering process is turned on or off. In such a case, a negative determination is made in the determination in step 112, and a series of calibration operations is completed.

As described above, in the touch panel device of the present embodiment, when a part of the touch panel 30 is touched with a finger, the capacitance increases in the peripheral region of the finger contact position, but the increasing capacitance is reduced (cancelled). Therefore, when the filtering process is performed by the filtering unit 102, a capacitance having a polarity opposite to the increased capacitance is generated in a specific region near the peripheral region. Then, when calibration is performed while touching a part of the touch panel 30, the capacitance after that is detected based on the capacitance of the opposite polarity, so that the filtering process is turned on / By switching off and observing the fluctuation of the capacitance based on the capacitance of the opposite polarity, it is possible to know that the calibration was performed while touching a part of the touch panel 30, and the calibration was performed. Can be redone. Therefore, even when the capacitance around the contact position is corrected by the filtering process, correct calibration can be performed regardless of the presence or absence of contact with a finger or the like.

The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the gist of the present invention. For example, in the above-described embodiment, the touch panel device included in the in-vehicle device 1 has been described, but the present invention can also be applied to the touch panel device included in a mobile terminal device, a device used indoors, or the like.

Further, in the above-described embodiment, the strength of the filter processing unit 102 may be set (changeable) to the extent that the capacitance that increases or decreases in the peripheral region is reduced. In this case, when the calibration processing unit 104 determines whether or not there is a change in capacitance between the case where the filtering process is performed and the case where the filtering process is not performed, it is desirable to strongly set the degree of this reduction. The capacitance of opposite polarity generated in a specific region by the filtering process increases as the degree of setting of the filtering processing increases. Therefore, by increasing the degree of setting, the finger contact at the time of calibration is determined more reliably. It becomes possible to do.

As described above, according to the present invention, even when the capacitance around the contact position is corrected by the filter processing, correct calibration can be performed regardless of the presence or absence of contact with a finger or the like.

1 In-vehicle device 20 Display processing unit 22 Display device 30 Touch panel 32 Touch panel control unit 100 Capacitance detection unit 102 Filter processing unit 104 Calibration processing unit 106 Position detection unit

Claims (4)

A touch panel device in which a capacitive touch panel is placed on the surface of the display screen of the display device.
The touch panel having a plurality of electrodes arranged so as to intersect each other,
Capacitance detecting means for detecting the capacitance between a pair of electrodes intersecting on the touch panel corresponding to each intersecting position.
A filter processing means that performs a filter process that reduces the capacitance that increases in the peripheral area when the user touches a part of the touch panel with a finger.
A position detecting means for detecting a position on the touch panel touched by the user with a finger based on the capacitance detected by the capacitance detecting means and after the filtering process is performed.
Calibration that sets the capacitance that is the reference of the detection operation by the capacitance detecting means by actually detecting the capacitance by the capacitance detecting means prior to the position detecting operation by the position detecting means. Calibration means to execute the operation and
The calibration means determines whether or not there is a change in capacitance between the case where the filter processing is performed and the case where the filter process is not performed after the calibration is executed, and if there is a change, the calibration is executed again. A touch panel device characterized by this. The calibration means acquires two types of capacitance according to the presence or absence of the filtering process with respect to the capacitance detected by the capacitance detecting means, and is based on these two types of capacitance. The touch panel device according to claim 1, wherein the presence or absence of fluctuation in capacitance is determined. By performing the filter processing on the capacitance detected by the capacitance detecting means when the user touches a part of the touch panel with a finger, the user touches the touch panel with a finger in the peripheral area. The touch panel device according to claim 1 or 2, wherein a capacitance having a polarity opposite to that corresponding to the position appears. The filtering means can be set to a strength that reduces the capacitance that increases or decreases in the peripheral region, and the capacitance is determined by the calibration means when the filtering is performed or not. The touch panel device according to any one of claims 1 to 3, wherein the degree of reduction is strongly set when determining the presence or absence of fluctuation.

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