JP2012043029A - Touch panel and input determination method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a touch panel capable of highly accurately determining an erroneous touch and an unoperated input; and to provide an input determination method thereof.SOLUTION: A touch panel 1 is formed by disposing an electrode pair comprising a reflecting electrode 15 and a detecting electrode 18 facing each other, into a matrix; the touch panel 1 includes a touch-side electrode plate 3 and a non-touch-side electrode plate 4 disposed facing each other; the touch-side electrode plate 3 is mounted with the reflecting electrode 15, while the non-touch-side electrode plate 4 is mounted with the detecting electrode 18 and a drive electrode 17 and includes a high-frequency signal source connected to the drive electrode 17 and a detecting unit 23 connected to the detecting electrode 18; and the touch-side electrode plate 3 is configured to be bent or displaced with respect to the non-touch-side electrode plate 4 by application/removal of a pressing pressure.

Description

  The present invention relates to a touch panel and an input determination method in the touch panel.

  Touch panels that perform input by bringing a finger into contact with a panel-like keyboard are widely used in personal computers, cash handling machines, ticket vending machines, and the like.

Various types of touch panels such as a resistive film type and a capacitance type have been developed.
For example, as shown in FIG. 6, the resistive touch panel includes resistive film sheets 102 and 103 whose intervals are maintained by dot spacers 104, and the pair of resistive film sheets 102 and 103 is a dot unless input is performed by fingers or the like. Although it is separated by the spacer, when there is an input operation, the resistance film sheet comes into contact with it, voltage change occurs, and input is performed (see Patent Document 1).

JP 08-54977

  Although many developments have been made on these touch panels, the main point of technical development is a technique for determining an erroneous input. When the touch panel is pressed with the palm, the touch panel is pressed due to a non-input operation such as the so-called touch prevention technology that prevents the address from being identified due to the multi-point input state or an object placed on the touch panel. In this case, development of a technology that determines that the input is not an input operation but a non-operation input is underway, but satisfactory results have not been obtained so far, which is one of the factors that degrade the performance of the touch panel. Yes.

  The present invention has been made in view of the circumstances as described above, and an object of the present invention is to provide a touch panel and an input determination method for determining touch and non-operation input with high accuracy.

  Corresponding to this object, the touch panel according to the present invention is a touch panel in which electrode pairs composed of opposing reflective electrodes and detection electrodes are arranged in a matrix, and the touch panel is an opposing touch side electrode. A non-touch side electrode plate, the reflective electrode is attached to the touch side electrode plate, the detection electrode is attached to the non-touch side electrode plate, and a drive electrode is attached to the drive electrode. A high-frequency signal source connected to the detection electrode and a receiving unit connected to the detection electrode, wherein the touch-side electrode plate is configured to be displaced with respect to the non-touch-side electrode plate by applying or depressing pressure. Yes.

The input determination method for a touch panel according to the present invention is a touch panel in which electrode pairs composed of opposing reflective electrodes and detection electrodes are arranged in a matrix, and the touch panel includes a touch-side electrode plate disposed opposite to the touch panel. A non-touch side electrode plate, the reflective electrode is attached to the touch side electrode plate, the detection electrode is attached to the non-touch side electrode plate, and a drive electrode is attached to the drive electrode. In the touch panel configured to have a high-frequency signal source and a receiving unit connected to the detection electrode, the touch-side electrode plate is displaced with respect to the non-touch-side electrode plate by the application of pressing force,
The touch is detected by detecting an outflow of a high-frequency current through a conductor approaching or in contact with the touch-side electrode plate to identify the address of the matrix and changing the capacitance between the reflective electrode and the detection electrode. It is characterized in that the pressing of the side electrode plate is determined.

  In the touch panel of the present invention, the individual switch elements constituting a large number of switch groups are of a non-contact type. This solves the problems of contact failure and deterioration over time, which are considered to be major issues with regard to switches.

  Each switch element employs a high frequency induction method. By this method, the ON / OFF operation of the switch circuit and the address determination, that is, the selection of the switch position can be performed separately, so that all ON / OFF mechanisms can be shared regardless of the number of switches (only one ON / OFF mechanism is provided) No). This is also a prerequisite for enabling the present invention. Specifically, among a large number of matrix switch groups, the switch is selected by simply bringing the finger close to the target switch position. On the other hand, the ON condition is satisfied, but all other switches that are not selected are invalidated. Therefore, only the target switch is determined to be ON, and the “hand touch” that is an issue on the touch panel Malfunction can be prevented.

  Furthermore, if the touch panel is pushed down without determining the position of the target switch, it does not push down the touch panel with a finger, but a signal indicating that a load or the like has been placed on the touch panel, and signal processing is not performed. Disabled.

  Also, the touch panel address specification and touch panel push-down operation can be determined by the continuous change of the high-frequency current detected by the detection device, so it can be determined by the integration result in one memory. The amount of calculation for determination can be reduced, and the memory capacity may be small.

  According to the first aspect of the present invention, information on the approach and contact of the finger with respect to the touch-side electrode plate and information on the capacitance between the electrode on the touch-side electrode plate and the electrode on the non-touch-side electrode plate are obtained. Therefore, it is possible to determine whether the address is specified and consciously press the touch side electrode plate, and erroneous input can be prevented.

  According to the invention described in claim 2, since the elastic material is interposed between the touch side electrode plate and the non-touch side electrode plate in the peripheral portion, the operation of the touch side electrode plate is made smooth and highly accurate, and Since the transparency is not impaired, a highly accurate touch panel can be obtained.

  According to the third aspect of the present invention, it is possible to specify an address by detecting the outflow of a high-frequency current, and it is possible to detect an input error by detecting a change in capacitance and detecting a push on the touch side panel. Can be easily prevented.

  According to the invention described in claim 4, it is possible to determine the address of the matrix by detecting the outflow of the high frequency current passing through the conductor approaching or touching the touch side electrode plate, and between the reflective electrode and the detection electrode. Since the pressing of the touch-side electrode plate is determined by the change in capacitance, the input operation can be determined quickly.

  According to the fifth aspect of the present invention, the determination and pushing of the address to the touch side electrode plate are determined from the change characteristic of the signal detected by the detection electrode, so that a quick determination is possible.

  According to the sixth aspect of the present invention, the determination and depressing of the address to the touch side electrode plate are determined by the integration result of the high frequency current from the detection electrode, so that a quick determination is possible and the capacity of the memory is small. Good.

Plane explanatory diagram of the touch panel Partial cross-sectional explanatory drawing of touch panel An explanatory perspective view showing the reflective electrode and the input / output electrode Circuit diagram showing equivalent circuit at input on touch panel Graph showing change in voltage Cross-sectional explanatory drawing showing a conventional resistive touch panel

An embodiment of the present invention will be described below with reference to the drawings.
1 to 3, reference numeral 1 denotes a touch input device touch panel. The touch panel 1 has a counter plate 2. The counter plate 2 is configured by disposing the touch side electrode plate 3 and the non-touch side electrode plate 4 to face each other at a constant interval. The touch side electrode plate 3 is configured by providing a reflective electrode 15 on a flat plate 9, and the non-touch side electrode plate 4 is configured by providing an input / output electrode 16 and a drive electrode 17 on a flat plate 10. In this embodiment, flat plates 9 and 10 are used as two plate bodies. That is, the counter plate 2 is composed of two flat plates 9 and 10. The flat plates 9 and 10 are arranged to face each other, and the flat plate 9 can be bent or displaced in a direction facing the flat plate 10. The distance between the flat plate 2 and the flat plate 4 is maintained by a frame-shaped spacer 6 made of an elastic material in the peripheral portion.

  As shown in FIG. 2, a large number of reflective electrodes 15 arranged in a matrix 24 are arranged on the inner surface of one of the two flat plates 9, 10 of the counter plate 2. Corresponding to each reflective electrode 15, an input / output electrode 16 is disposed on the inner surface of the other flat plate 10 at a substantially opposed position. The input / output electrode 16 is a combination of the drive electrode 17 and the detection electrode 18. The drive electrodes 17 arranged on the same row or column of the matrix are connected to the row or column, and the detection electrodes 18 arranged on the same column or row are connected to the column or row. Connected to the line.

  A high-frequency signal source 22 is connected to the drive electrode 17, and a detection unit 23 is connected to the detection electrode 18.

  The two flat plates 9 and 10 of the counter plate 2 are made of a transparent material such as glass or plastic, and the drive electrode 17 and the detection electrode 18 are also made of a transparent material. As an example, the reflective electrode 15, the drive electrode 17, and the detection electrode 18 can be formed by sputtering indium oxide. In order to shield the input / output electrodes 16 extending in the row direction and the column direction of the other flat plate 10, in one flat plate 9 provided with the reflective electrode 15, a portion where the reflective electrode 15 is arranged is formed in a window shape. Exclude the shield on all other remaining surfaces.

  The common connection lines for the respective rows and columns of the other flat plate 10 are drawn to the outside and connected to the high-frequency signal source 22 and the detection unit 23.

The operation of the touch panel 1 configured as described above is as follows.
As a finger approaches the reflective electrode 15 of each touch-side electrode plate 3 as a touch input operation, a part of the high-frequency current reaching the reflective electrode 15 from the drive electrode 17 flows out to the ground through the finger 21, so The circuit is as shown in FIG. 4 (b), and the reception signal level of the detection electrode 18 at that position changes in the negative direction (changes 1 to 5 in FIG. 5 (c)). After the finger touches the touch side electrode plate 3, the reflective electrode 15 approaches the input / output electrode 16 of the non-touch side electrode plate 4 by further depressing the touch side electrode plate 3, In the equivalent circuit, as shown in FIG. 4C, a change in the positive direction of the signal level caused by an increase in the high-frequency current from the drive electrode 17 to the detection electrode 18 (5-7 in FIG. 5C). Change) and measure the coordinate position of the electrode pair. To identify the Tenomi ON operation. This two-stage specific operation can prevent a so-called "hand touch" malfunction that occurs on the touch panel.

Changes in the equivalent circuit and the high-frequency current in the operation of the touch panel 1 configured as described above are as follows.
When the finger approaches the reflective electrode 15 of each touch side electrode plate 3 as a touch input operation, as shown in FIGS. 4A, 4B, and 4C, a part of the high-frequency current I is impedance of the finger. It flows out to the ground as I ₂ through Z, and the rest flows into the detector as I ₁ . If Z is assumed to be ∞ when the finger is away from the reflective electrode and becomes almost zero when the panel is touched, I ₁ and I ₂ can be expressed as follows.
(1) When Z is ∞ I ₂ = 0
I ₁ = (1/2) jωce = 1
(2) When Z is 0 I ₂ = jωCe
(Immediately after the finger touches) I ₁ = (1/2) jωCe−I ₂ = − (1/2) I ₂
(3) The finger pushes in with the pressure P I ₂ = KPjωCe
I ₁ = − (1/2) I ₂ + KPjωCe
(4) Put your finger back and release I ₂ = 0
I ₁ = (1/2) jωCe-I
Same as (1)
K: C increase rate per unit pressing
P: The change pattern of the finger pressure I ₁ is schematically shown in FIG. A dedicated one-chip microcomputer confirms the address of the touch panel that was pressed at the end of this cycle and that it was pressed securely. Since such a change may occur at any point of the entire matrix that forms the entire touch panel, it is necessary to check repeatedly in sequence. Therefore, the waveform at each point is required to achieve its purpose with as few samplings as possible. Therefore, if all waveforms are read as they are, it will not be in time. Therefore, the following measures were taken. As shown in FIG. 5, first, when this original waveform is approximately regarded as a sine wave, this becomes y = −Sinx (FIG. 5B).
When the sampling values at each point of the matrix are added to the corresponding memories, the input original waveform is integrated and expressed by the following equation (FIG. 5C).
∫ydy = ∫ (−Sinx) dx = Cosx−1
Using this figure, the address to be pushed is specified by the change (1-5) in the section from 0 to π, and the switch is pushed by the change (5-7) in the section from (3/2) π. Judge that. In this case, since there is no change other than the address to be pressed, reading is stopped and the reading is concentrated only on this address. This is a means for saving reading time, and is necessary because high response is required when there are many touch panels. In this way, the “handling”, which is a major problem, can be prevented by separately specifying the address and determining that the address has been pressed. For example, when the palm is placed on the touch panel, first, the change for specifying the address appears in a plurality of places. In this case, the processing as “hand touch” can be performed.
Further, when an object is placed on the touch panel, the value corresponding to the impedance Z of the finger is ∞, so that no change is caused by high frequency induction and nothing is recognized, so this is ignored. An even greater advantage of this method is that all these operations are performed by high-frequency induction through the fingers and do not go through a mechanism such as a contact, so that malfunctions such as contact failure can be completely eliminated.

  As described above, according to the present invention, it is possible to obtain a touch panel and an input determination method thereof that can accurately determine the touch and non-operation input.

DESCRIPTION OF SYMBOLS 1 Touch panel 2 Opposite plate body 3 Touch side electrode plate 4 Non-touch side electrode plate 6 Spacer 9 Flat plate 10 Flat plate 15 Reflective electrode 16 Input electrode 17 Drive electrode 18 Detection electrode 21 Finger 22 High frequency signal source 23 Detection part 24 Matrix

Claims (6)

  A touch panel in which electrode pairs composed of opposing reflective electrodes and detection electrodes are arranged in a matrix, wherein the touch panel has a touch-side electrode plate and a non-touch-side electrode plate arranged to face each other, and The reflective electrode is attached to the touch side electrode plate, the detection electrode is attached to the non-touch side electrode plate and the drive electrode is attached, and the high frequency signal source connected to the drive electrode and the detection electrode are connected A touch panel, comprising: a detection unit, wherein the touch-side electrode plate is configured to be displaced with respect to the non-touch-side electrode plate by applying or pressing pressure.   2. The touch panel according to claim 1, wherein the one electrode plate and the other electrode plate are supported by a spacer made of an elastic material in a peripheral portion so as to be relatively displaceable with each other.   It is possible to detect an outflow of a high-frequency current passing through a conductor that is close to or in contact with the touch side electrode plate, and to detect a change in capacitance between the reflective electrode and the detection electrode. The touch panel according to claim 1. A touch-side electrode plate in which reflective electrodes are arranged in a matrix and a non-touch-side electrode plate having a drive electrode and a detection electrode in a position corresponding to the reflective electrode are arranged opposite to each other and connected to the drive electrode In a touch panel having a signal source and a detection unit connected to the detection electrode, the touch side electrode plate is configured to be displaced with respect to the non-touch side electrode plate by applying and removing a pressing force.
The touch is detected by detecting an outflow of a high-frequency current through a conductor approaching or in contact with the touch-side electrode plate to identify the address of the matrix and changing the capacitance between the reflective electrode and the detection electrode. INPUT DETERMINING METHOD FOR TOUCH PANEL, DETERMINING DEPRESSION OF SIDE ELECTRODE PLATE   5. The input determination method for a touch panel according to claim 4, wherein address determination of the matrix and depression of the touch side electrode plate are determined from a change characteristic of a signal detected by the detection electrode.   5. The touch panel according to claim 4, wherein the address specification and the push-down operation of the touch-side electrode plate are determined based on an integration result in a memory obtained by integrating the high-frequency current detected by the detection electrode.

Images