JP7017205B2 - Position detector - Google Patents

Description

The present invention relates to a position detection device that detects the position of an approaching object.

Patent Document 1 discloses an example of a conventional capacitive touch panel. The touch panel described in Patent Document 1 has a plurality of first electrodes juxtaposed on an insulating substrate, a plurality of second electrodes juxtaposed across the first electrode, and insulation interposed between the two electrodes. When the film is provided and viewed in a plane, the pad portion of the first electrode and the pad portion of the second electrode are arranged without overlapping (see FIG. 2 of Patent Document 1).

Japanese Unexamined Patent Publication No. 2010-146785 Japanese Unexamined Patent Publication No. 2008-134522 Japanese Unexamined Patent Publication No. 2013-250642

A capacitive touch panel using such a patterned two-layer structure electrode pad (hereinafter, also referred to as a two-layer structure touch panel) can achieve relatively high touch detection accuracy, but its structure is complicated. , There is a demerit that the cost becomes high.

On the other hand, Patent Document 2 and Patent Document 3 disclose a patternless touch panel in which electrodes are provided at four corners of a transparent conductive film and an AC voltage for position detection having the same phase and the same potential is supplied. Specifically, in Patent Document 2, four waveform detection circuits are provided corresponding to the electrodes at the four corners of the conductive film, and the coordinate positions are calculated based on the output voltage of the detection circuits. Further, in Patent Document 3, pulse signals having the same phase and the same voltage are applied to the electrodes at the four corners of the rectangular conductive film, and the user's touch position is detected using the logarithmic signal ratio.

A patternless touch panel using such a single conductive film has a simple structure and has an advantage that it can be realized at a low price, but generally has a lower resolution than a two-layer structure touch panel. In particular, in the prior art as in Patent Document 2, there is a problem that it is difficult to detect a so-called two-point touch that touches two different points on a touch panel.

In view of the above points, it is an object of the present invention to detect the touch position of a two-point touch in addition to the one-point touch with high accuracy in a patternless touch panel.

The position detection device according to one aspect of the present invention includes a signal input node and a conductive layer having orthogonal and / or opposite sides, and at least two electrodes each at an intermediate position between at least two sides of the conductive layer. Is provided, a signal source that gives a measurement signal to the signal input node of the base portion, and a signal propagating from the signal input node via the conductive layer, and is selected from the same side of the conductive layer among the electrodes. The same side pair electrode consisting of the paired electrodes, the diagonal pair electrode consisting of one electrode selected from each of the diagonal sides of the conductive layer, or one selected from each of the opposite sides. It is provided with a position detection unit that calculates the position of an object close to the conductive layer based on the difference information of the measurement signal output from the measurement electrode selected from the opposite pair of electrodes consisting of the electrodes. It is a feature.

Here, in the "base portion provided with the conductive layer", a conductive film is formed on, for example, a base member formed of an insulator, for example, a transparent insulating substrate, a resin housing such as an electronic device, or the like. Including those that are. Further, the base portion includes one provided with two conductive layers. That is, the base portion is uniformly formed in a detection region including a sheet-like substrate having an insulating property and a central portion on the back surface side of the substrate, and the signal input node is provided on the peripheral portion. It may be provided with the signal input layer and the conductive layer uniformly formed in the detection region on the surface side of the substrate.

On the other hand, the conductive layer may be one layer. That is, the conductive layer includes a member in which one conductive layer is formed on a base member formed of an insulator, and a part or all of the substrate as a base portion is composed of the conductive layer. Includes what is. Further, the case where the base portion is composed of only one conductive layer is also included. In this case, the conductive layer includes all those having conductivity and having a layer formed therein, and in addition to the conductive film, for example, a conductive film, a conductive sheet, and a conductive plate are also included. Then, the signal input node may be connected to the electrode of the conductive layer.

According to this aspect, the touch position is detected based on the difference information of the signal output from the measurement electrode selected from the same-side pair electrode, the diagonal pair electrode, and the opposite pair electrode. This makes it possible to select the electrodes so that the relative positions of the measurement electrode and the touch position are different distances. Therefore, the signal difference of the output signal from the measurement electrode obtained by the position detection device can be increased, and sufficient touch detection sensitivity can be obtained. Here, "touch" is a concept including both a direct touch to the display screen (contact with the display screen) and an indirect touch to the display screen (so-called hovering).

The position detection unit may use at least two types of pair electrodes of the same side pair electrode, the diagonal pair electrode, or the opposite pair electrode as the measurement electrode.

As a result, sufficient sensitivity can be obtained by the signal difference due to the distance where the relative positions of the measurement electrode and the touch object position are different. Therefore, even when a two-point touch is performed, a sufficiently large value can be obtained as the difference information, and the two-point touch can be detected with high accuracy in addition to the one-point touch.

According to the position detection method according to the present invention, the touch position can be detected with high accuracy in the patternless touch panel.

It is a block diagram which shows the structural example of the position detection apparatus which concerns on 1st Embodiment. It is a top view which shows the structure of the touch panel which concerns on 1st Embodiment. It is sectional drawing which shows the structure of the touch panel which concerns on 1st Embodiment. It is a figure for demonstrating the position detection principle of the touch panel which concerns on 1st Embodiment. It is a figure which showed the example of the signal waveform when the point TP was touched in FIG. 4 or FIG. It is a block diagram which shows the structural example of the position detection apparatus which concerns on 2nd Embodiment. It is sectional drawing which shows the structural example of the touch panel which concerns on 2nd Embodiment. It is a top view which shows the structural example of the touch panel which concerns on 2nd Embodiment. It is a figure for demonstrating the position detection principle of the touch panel which concerns on 2nd Embodiment. It is a flow chart which shows an example of the touch position detection method which concerns on 2nd Embodiment. It is a flow diagram which shows an example of the acquisition operation of no-touch correction data. It is a flow diagram which shows an example of the touch position detection operation. It is a figure which shows an example of the weighting data of deep learning. It is a figure which shows an example of the calculation result of deep learning. It is a top view which shows the structural example of the touch panel which concerns on 2nd Embodiment. It is a top view which shows the structural example of the touch panel which concerns on 2nd Embodiment. It is a top view which shows the structural example of the touch panel which concerns on 2nd Embodiment. It is a figure which shows the relationship between the touch position of a two-point touch and a peak voltage. It is a figure which shows the relationship between the touch position of a two-point touch and a peak voltage. It is a top view which shows the other configuration example of a touch panel. It is a top view which shows the other configuration example of a touch panel.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that the following description of the preferred embodiment is essentially merely an example and is not intended to limit the present invention, its scope of application or its use.

<First Embodiment>
FIG. 1 is a block diagram showing a configuration example of the position detection device 1 according to the present embodiment. FIG. 2 is a plan view showing the configuration of the touch panel 2, and FIG. 3 is a cross-sectional view thereof.

As shown in FIG. 1, the position detection device 1 includes a patternless touch panel 2 (hereinafter, simply referred to as a touch panel 2) and a position detection unit 6. The position detection unit 6 includes a signal source 3 for giving a pulse signal as a measurement signal to the touch panel 2, a position information acquisition unit 60, and a calculation unit 5.

The touch panel 2 is configured to include a conductive sheet 20 having a sheet-shaped (film-shaped or thin plate-shaped) substrate 21.

-Conductive sheet-
As shown in FIGS. 2 and 3, on the surface of the substrate 21, in the rectangular detection region Rd including the central portion thereof, the detection layer 31 as the conductive layer, the insulating layer 32, and the insulating layer 32 are arranged in order from the one closest to the substrate 21. The ground layers 33 are uniformly formed and laminated. Similarly, on the back surface of the substrate 21, the signal input layer 41 is uniformly formed in the detection region Rd. The detection region Rd corresponds to a region for detecting the touch position when the conductive sheet 20 is used as a member of the patternless touch panel. In this embodiment, for convenience of explanation, it is assumed that the surface of the substrate 21 faces the operator. Further, "front" refers to the operator side, and "rear" refers to the opposite side. However, the conductive sheet 20 of the present disclosure is not limited to the touch operation from the surface side of the substrate 21. That is, it is possible to handle a touch operation from the back surface side of the conductive sheet 20, and the same effect can be obtained with the same configuration.

When the conductive sheet 20 is used as a member of the patternless touch panel, the substrate 21 is preferably made of an insulating material from the viewpoint of preventing a short circuit due to contact between another member and the detection layer 31. The substrate 21 according to the present embodiment includes a substrate 21a having a predetermined thickness and an insulating film 21b attached to the surface of the substrate 21a with an adhesive film (for example, an OCA (Optical Clear Adhesive) film).

The material of the substrate 21 may be any material having an insulating property, and is not particularly limited. For example, a hard plate such as alumina or a glass cloth impregnated epoxy resin “so-called FR4 (Flame Retardant Type 4) substrate”, made of resin. One or more materials selected from the group consisting of films and rubber materials (preferably flexible) can be used. Above all, an FR4 substrate having a low dielectric constant is desirable from the viewpoint of reducing the capacitance between the detection layer 31 and the signal input layer 41. Specific examples of the resin film include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), cycloolefin polymer (COP), polycarbonate (PC), polyimide (PI), polyvinyl chloride (PVC), and triacetate. Examples thereof include triacetyl cellulose (TAC), and PET film is more preferable from the viewpoint of heat resistance and cost.

The thickness of the substrate 21 is determined from the viewpoint of obtaining good signal propagation performance between the signal input layer 41 and the detection layer 31, for example, the touch capacitance value and the touch position formed between the signal input layer 41 and the detection layer 31. It is determined based on the impedance and the like from the position detection unit 6 to the position detection unit 6. If the thickness of the substrate 21 is not sufficiently secured, in the position detection unit 6 (see FIG. 8), when the capacitance between the signal input layer 41 and the detection layer 31 is relatively large with respect to the touch capacitance, Sufficient output signal may not be obtained. Specifically, it is preferable that the thickness of the substrate is 0.8 mm or more and 6.8 mm or less.

On the surface of the substrate 21, the detection layer 31 is uniformly formed in the rectangular detection region Rd, and a plurality of output wirings 53 are formed in the wiring region Rw surrounding the detection region Rd. The detection region Rd corresponds to a region for detecting the touch position when the conductive sheet 20 is used as a member of the patternless touch panel. In other words, the conductive sheet 20 of the present invention is configured to be mounted on a patternless touch panel so that the presence or absence of a touch operation can be detected by the position detection unit 6 (see FIG. 8). The detection layer 31 is uniform in the detection layer forming region R1 slightly wider than the detection region Rd from the viewpoint of avoiding the generation of capacitance between the electrode E or the output wiring 53 and the signal input layer 41 or the ground layer 33. It is desirable that it is formed in. Even in this case, it can be said that the detection layer 31 is uniformly formed in the detection region Rd.

On each side of the detection layer 31 (corresponding to the peripheral edge), a plurality of electrodes E (corresponding to the signal output node No.) at equal pitches at intermediate positions in the longitudinal direction of the sides at predetermined intervals from the corners of each side. Is formed. The number of electrodes E and the number of output wirings 53 in the wiring area described later are equal to each other. FIG. 2 shows an example in which three electrodes E are provided on each side of the detection layer 31. In addition, in this embodiment, "equal" may be substantially equal, and the same effect can be obtained even if there is some misalignment. Therefore, "equal" is a concept that includes approximately equality in addition to equality (perfect match).

In the present embodiment, the touch operation is a concept including an operation of directly touching the touch panel and a hovering operation. Further, performing the above-mentioned "touch operation" is referred to as "touching". Further, the position on the detection layer 31 corresponding to the position of the indicator (for example, the finger of the operator) when the "touch operation" is performed is referred to as the "touch position".

The detection layer 31 includes carbon, silver, copper, aluminum, indium tin oxide (ITO), fluorine-doped tin oxide (FTO), metal-doped zinc oxide, metal nanowires, antimonated tin oxide (ATO), polythiophene (PEDOT), and the like. It contains one or more conductive materials selected from the group consisting of polyaniline and water-soluble sulfonated polyaniline. The carbon is not particularly limited as long as it exhibits conductivity, and for example, carbon black, graphene, and carbon nanotubes can be used.

A plurality of output wirings 53 extending along the peripheral edge of the detection layer 31 are formed in the wiring region Rw on the surface of the substrate. The output wiring 53 is used for acquiring the current output from the electrode E as the signal output node No. of the detection layer 31. In other words, each output wiring 53 is connected to the detection layer 31 via an electrode E provided so as to be separated from each other, and this electrode E acts as a signal output node. Further, each output wiring 53 is routed along the peripheral edge of the detection layer 31, gathered at one place (near the lower right corner in FIG. 2), and connected to different electrodes E, respectively. By consolidating the ends (electrodes) of the output wiring 53 in this way, it becomes easy to connect to the position detection unit 6.

On the surface side of the detection layer 31 and the output wiring 53, a conductive grounding layer 33 is uniformly formed by stacking via an insulating layer 32. A signal input node Ni is provided at an intermediate position on the upper side (corresponding to a peripheral portion) of the ground layer 33 on the left-right side of the drawing. A second input wiring 52 wider than the output wiring 53 is connected to the signal input node Ni. The second input wiring 52 is
A signal input layer 41 is formed on the back surface of the substrate 21. The signal input layer 41 is uniformly formed in the signal input layer forming region R3 having substantially the same width as the detection region Rd. The ground layer 33 and the signal input layer 41 are arranged so that their positions in the conductive sheet 20 in a plan view are substantially the same.

A signal input node Ni is provided at an intermediate position on the upper side (corresponding to a peripheral portion) of the signal input layer 41 on the left-right side of the drawing. A first input wiring 51 wider than the output wiring 53 is connected to the signal input node Ni. The first input wiring 51 and the second input wiring 52 are arranged so that their positions in the conductive sheet 20 in a plan view are substantially the same.

Specifically, as shown in FIG. 3, the first input wiring 51 and the second input wiring 52 extend from the input node Ni in the upward direction of the drawing, and then along the peripheral edge of the conductive sheet 20 in the right direction of the drawing and below the drawing. It extends in an L-shape toward the direction to an intermediate position in the vertical direction on the right side of the drawing.

A pulse generator 71 of a position detection unit 6, which will be described later, is connected to the tip portions of the first input wiring 51 and the second input wiring 52. Then, the measurement signal from the pulse generator 71 is supplied to the signal input node Ni via the first input wiring 51 and the second input wiring 52.

Here, as shown in FIG. 2, the first input wiring 51, the second input wiring 52, and the output wiring 53 are formed so as not to overlap each other in a plan view. As a result, it is possible to avoid the generation of inter-wiring capacitance between the first input wiring 51 and the output wiring 53 and between the second input wiring 52 and the output wiring 53.

As shown in FIG. 3, the front surface of the ground layer and the back surface of the signal input layer 41 may be covered with an insulating cover layer. On the other hand, for example, when a space is provided in front of and behind the conductive sheet 20, insulating parts are arranged, or when the conductive sheet 20 is covered with a housing or the like, an insulating cover layer is provided. It does not have to be.

Returning to FIG. 1, the signal source 7 has a pulse generator 71 (denoted as PG in FIG. 1). The pulse generator 71 generates a rectangular pulse signal (voltage: Vcc) that fluctuates periodically. The output of the pulse generator 71 is given to the signal input node Ni of the signal input layer 41 and the ground layer 33.

The position information acquisition unit 60 includes two analog switches 61 and 61 (denoted as AS in FIG. 1) having the same configuration, a differential amplifier 62, a noise filter 63, a peak hold unit 64, and an analog-to-digital conversion circuit 65. (Indicated as ADC in FIG. 1).

The analog switches 61 and 61 pass an output signal from a pair of electrodes (hereinafter referred to as measurement electrodes E1 and E2) to be measured arbitrarily selected from the electrodes E provided on the detection layer 31.

The differential amplifier 62 receives the output signal of the measurement electrode via the analog switches 61 and 61, and outputs a differential signal indicating the difference in signal amount between the two signals. The noise filter 63 removes the noise component of the differential signal output from the differential amplifier 62. The peak hold unit 64 holds the peak voltage of the differential signal from which noise has been removed as an analog signal. The analog-to-digital conversion circuit 65 converts the peak voltage value and the code information of the peak voltage into digital values based on the peak voltage (analog signal).

The combination of the measurement electrodes includes the same side pair electrode, the opposite side pair electrode, and the diagonal pair electrode. The same-side pair electrode is a pair electrode selected from the electrodes provided on any one side of the conductive layer, and for example, the combination of electrodes described in the “same-side acquisition” column of FIG. 13 is used. included. The opposite side pair electrode is a pair electrode selected one by one from the opposite sides, and includes, for example, the combination of electrodes described in the “opposite side acquisition” column of FIG. The diagonal pair electrode is a pair electrode selected one by one from the orthogonal sides, and includes, for example, the combination of electrodes described in the “diagonal acquisition” column of FIG.

The calculation unit 5 controls the operation of each block of the position detection device 1.

For example, the arithmetic unit 5 selects a measurement electrode from the timing-controlled input signal bals transmission and pair electrodes, and uses the electrode selection signal SC1 indicating the selected measurement electrode as an analog of the signal source 3 and the position information acquisition unit 60. It transmits to switches 61 and 61. Further, the arithmetic unit 5 determines the position of an object (for example, a user's finger) that has approached or touched the touch panel 2 based on the difference information included in the differential signal (digital value) output from the analog-to-digital conversion circuit 65. Obtained by calculation. Here, the difference information refers to all the information obtained based on the differential signal. For example, the difference information includes code information indicating whether the differential signal is a positive voltage signal or a negative voltage signal, voltage difference information indicating the magnitude of the differential signal, and until the differential signal reaches a predetermined voltage. Includes time information, etc.

-Touch panel position detection principle-
Hereinafter, the principle of detecting the touch position related to the touch operation of the patternless touch panel according to the first embodiment will be specifically described. FIG. 4 is a schematic view showing a state in which a pulse generator 71 of a position detection unit 6 and a differential amplifier 62 are connected to the conductive sheet 20 in a patternless touch panel using the conductive sheet 20. In FIG. 4, Z indicates the impedance between the signal input layer 41 and the detection layer 31 and the impedance between the detection layer 31 and the ground layer 33. This impedance Z is matched to a predetermined value (for example, about 50Ω). In FIG. 4, the analog switches 61 and 61 are not shown.

In FIG. 4, the pulse generator 71 is connected to the signal input node Ni of the signal input layer 41 via the input resistor Ria. Further, an input resistor Rib is connected between the signal input node Ni of the signal input layer 41 and the signal input node Ni of the ground layer 33, and the signal input node Ni of the ground layer 33 is grounded.

Then, when a measurement signal is given from the pulse generator PG to the signal input node Ni, the measurement signal is propagated to the detection layer 31 via the substrate 21 and output as an output signal from the electrode E of the detection layer 31. The differential amplifier 62 is given output signals from the measurement electrodes E1 and E2 selected based on the control signal from the arithmetic unit 5 via the analog switches 61 and 61.

After that, the calculation unit 5 connected to the subsequent stage calculates the touch position.

Specifically, when a pulse signal is supplied to the signal input node Ni in a state where the touch position TP is touched, the touch position is charged up, and the measurement electrodes E1 and E2 correspond to the following equations (1), respectively. The voltage is output.

V = Vdd (1-exp (-t / RC)) ... (1)

_C = _CT + CS (2)

Here, the equation (2) shows the value of C in the equation (1). In the formula (2), _CT is the capacitance between the touched finger and the detection layer 31, and CS is the capacitance inside the conductive sheet 20 at the touch position _TP . It is desirable that CS is set so that the value of Ct / _Cs is about 1 to 100.

Further, R in the equation (1) includes R1 and R2, which are resistance values between the measurement electrodes E1 and E2 and the touch position, and the wiring resistance from the respective measurement electrodes E1 and E2 to the position detection device 6. The resistance component RZ of the impedance Z between the RL and the signal input layer 41 and the detection layer 31 is included. However, since the wiring resistance RL and the resistance component RZ can be reduced to the extent that there is almost no effect, the wiring resistance RL and the resistance component RZ are assumed to be "0 (zero)" in the following calculation.

Then, assuming that the resistance between one of the measurement electrodes E1 and E2 and the touch position TP is _R1 , the voltage represented by the following equation (3) is output to each of the electrodes E1.

V1 = Vdd (1-exp (-t / R ₁ C)) ... (3)

Similarly, assuming that the resistance between the other electrode E2 of the measurement electrodes E1 and E2 and the touch position TP is _R2 , the voltage represented by the following equation (4) is output to each of the electrodes E2.

V2 = Vdd (1-exp (-t / R ₂ C)) ... (4)

Therefore, the differential amplifier 62 outputs the differential signal shown in the following equation (5) (the difference signal of the equations (3) and (4)).

Vdf = V1-V2
= Vdd (-exp (-t / R ₁ C) + exp (-t / R ₂ C)) ... (5)

FIG. 5 is a diagram showing an example of an output signal of the measurement electrodes E1 and E2 and a differential signal output from the differential amplifier 62 when the touch position TP is touched by the user. In FIG. 5, the vertical axis is the voltage value and the horizontal axis is the time. Further, FIG. 5A shows the signal waveforms of V1 and V2 obtained by the equations (1) and (2) described later, and FIG. 5B shows the signal waveform of Vdf obtained by the equation (3). Shows.

Then, in the calculation unit 5 of the position detection unit 6, since the sign, magnitude, etc. (hereinafter referred to as differential signal information) of the differential signal represented by the equation (5) differ depending on the touch position, the differential signal. The touch position can be calculated based on the information.

The amplitude of the voltage detected by the position detection unit 6 differs depending on the type of touch operation (operation in which the indicator directly touches the touch panel and hovering operation), but the basic detection principle is irrespective of the type of touch operation. It is the same. Similarly, when the touch position is 1 point (so-called 1-point touch), when the touch position is 2 points (so-called 2-point touch), and when the touch position is 3 points or more (so-called multi-touch), the position is detected. The amplitude of the voltage detected by the unit 6 is different, but the basic detection principle is the same.

As described above, according to the present embodiment, the combination of the measurement electrodes includes the same side pair electrode, the opposite side pair electrode, and the diagonal pair electrode, so that the relative position between the measurement electrode and the touch position is different. The electrodes can be selected so that they are at a distance. As a result, the signal difference of the output signal from the measurement electrode obtained by the position detection device can be increased, and sufficient touch detection sensitivity can be obtained.

In the description of the above embodiment, a case where any one of the same-side pair electrode, the diagonal pair electrode, and the opposite pair electrode is selected as the measurement electrode has been described as an example. It is more preferable to use at least two types of pair electrodes as measurement electrodes. By doing so, the relative positions of the measurement electrode and the touch position can be set to different distances. As a result, the signal difference of the output signal from the measurement electrode obtained by the position detection device can be increased, and sufficient touch detection sensitivity can be obtained.

Further, the inventors of the present application set a detection region Rd for detecting the touch position on the insulating substrate 21, and uniformly provide a signal input layer 41 for giving a measurement signal to the back surface side of the detection region Rd. A conductive sheet 20 having a uniformly formed detection layer 31 formed on the surface side of the detection region Rd and having a signal output node No. for outputting a measurement signal propagated via the substrate 21 is used as a patternless touch panel. By using it, we found that it is possible to detect the touch position with high accuracy. Specifically, since the signal input layer 41 and the detection layer 31 are separated, it is possible to prevent signal interference between the signal input node Ni and the signal output node No.

In the description of the present embodiment, the detection region Rd is rectangular, and the detection layer 31 and the signal input layer 41 are rectangular, but the present invention is not limited to this. For example, as shown in FIG. 20, the detection region Rd (detection layer 31 and signal input layer 41) may have an elliptical shape, and a part of the detection region Rd (detection layer 31 and signal input layer 41) may be formed. It may be curved or curved. Even if a part of the detection area Rd is curved or curved, the principle of detecting the touch position is the same as that of the above embodiment, so detailed description thereof will be omitted here.

<Second Embodiment>
FIG. 6 is a block diagram showing a configuration example of the position detection device 1 according to the present embodiment. In FIG. 6, the blocks common to those in FIG. 1 are designated by the same reference numerals. In the following description, the points different from those of the first embodiment will be mainly described, and the description of the configuration common to the first embodiment may be omitted.

Specifically, in the second embodiment, the configurations of the touch panel 2, the calculation unit 5, and the signal source 7 are different from those in the first embodiment. In the following description, for convenience of explanation, among the electrodes E, the electrode provided along the side extending in the vertical direction at the left end of the detection layer 31 is referred to as a first electrode. Further, the electrodes provided on each side in the counterclockwise order from the first electrode are referred to as the second, third and fourth electrodes, respectively. Further, in order to facilitate understanding of the description, the first electrode / third electrode may be described with reference numerals E11 / E31, E12 / E32, and E13 / E33 in order from the top to the bottom of the drawing. be. Similarly, the second electrode / fourth electrode may be described with reference numerals E21 / E41, E22 / E42, and E23 / E43 in order from the right to the left in the drawings.

In FIG. 6, the signal source 7 has a pulse generator 71 (denoted as PG in FIG. 6) and an analog switch 72 (denoted as AS in FIG. 6). The pulse generator 71 generates a rectangular pulse signal (voltage: Vcc) that fluctuates periodically. The analog switch 72 outputs the pulse signal received from the pulse generator 71 to the measurement electrode (pair electrode to be measured) based on the electrode selection signal SC1 received from the calculation unit 5.

FIG. 7 is a cross-sectional view showing the configuration of the touch panel 2 according to the present embodiment, and FIG. 8 is a plan view of the same. In the present embodiment, the touch panel 2 is made of a rigid substrate or a flexible sheet having electromagnetic transparency (including light and a touch electric field), and includes a rectangular substrate 21 in a plan view. In the present disclosure, a rectangle is a concept including a square and a rectangle. On the surface of the substrate 21, an electromagnetically permeable detection layer 31 is formed over substantially the entire surface, and a transparent insulating protective layer 23 is formed on the detection layer 31. The detection layer 31 is, for example, an ITO (Indium Tin Oxide) film, and its resistance value is 1 kΩ / □ to 10 MΩ / □. The insulating protective layer 23 is, for example, a polyester sheet, and its thickness is, for example, 1 μm to 100 μm.

The calculation unit 5 controls the operation of each block of the position detection device 1. For example, the arithmetic unit 5 selects a measurement electrode from the timing-controlled input signal bals transmission and pair electrodes, and uses the electrode selection signal SC1 indicating the selected measurement electrode as an analog of the signal source 3 and the position information acquisition unit 60. It transmits to switches 61 and 61. Further, the arithmetic unit 5 is an object (for example, a user's finger) that has approached or touched the insulation protection layer 23 based on the difference information included in the differential signal (digital value) output from the analog-to-digital conversion circuit 65. Obtain the position by calculation. Here, the difference information refers to all the information obtained based on the differential signal. For example, the difference information includes code information indicating whether the differential signal is a positive voltage signal or a negative voltage signal, voltage difference information indicating the magnitude of the differential signal, and until the differential signal reaches a predetermined voltage. Includes time information, etc. Further, the arithmetic unit 5 includes a ROM 51 in which a program for performing various controls is stored, a correction table TB1 described later, and a database necessary for deep learning (deep learning learning data, weighting after deep learning learning). It includes a storage unit 52 in which data and data necessary for the perceptron method) are stored. The definition of the measurement electrode is the same as that of the first embodiment, and the pair electrode to be measured arbitrarily selected from the electrodes E provided on the detection layer 31, that is, the same side pair electrode, diagonally. It is a pair electrode arbitrarily selected from a pair electrode or a pair electrode facing each other.

-Touch position detection principle-
FIG. 9 is a diagram showing in detail the connection relationship between the third and fourth electrodes E33 and E43 of the touch panel 2 and the peripheral blocks in the position detection device 1. In the following description of the position detection principle, the pulse signal from the pulse generator 31 is given to the third and fourth electrodes E33 and E43 as measurement electrodes, and the differential amplifier 62 gives the third and fourth electrodes E33 and E43. It is assumed that a differential signal is output. That is, the case where the electrode selection signal SC1 indicates the third and fourth electrodes E33 and E43 will be described as an example. In the following description, in order to facilitate understanding, (1) the detection layer 31 will be described as having a uniform sheet resistance. (2) In FIG. 9, the analog switch 32 and the analog switch 61 are not shown. However, although the details will be described later, the present invention can be applied even when the sheet resistance of the detection layer 31 is partially different.

As shown in FIG. 9, the pulse generator 31 and the input terminals IN33 and IN43 of the third and fourth electrodes E33 and E43 are connected to each other via the reference resistance R0 by the input signal wiring NI. The output terminals OUT33 and OUT43 of the third and fourth electrodes E33 and E43 are connected to the input terminals of the differential amplifier 62 by output signal wiring NT, respectively. Two loads Z1 and Z1 having the same impedance are connected in series between both input terminals of the differential amplifier 62, and an intermediate node between the two loads Z1 and Z1 is connected to the ground.

Note that FIG. 9 shows an example in which the input signal wiring NI is paired with the first ground wiring NG1 running in parallel along the wiring NI for the purpose of coping with a severe noise electromagnetic environment. At this time, one end of the first ground wiring NG1 is connected to the ground of the pulse generator 31. Similarly, an example is shown in which the output signal wiring NT is paired with the ground wiring (hereinafter referred to as the second ground wiring NG2). One end of the second ground wiring NG2 is connected to the ground in the same manner as the intermediate node. Further, the other ends (ends on the touch panel side) of the first and second ground wirings NG1 and NG2 are open ends. However, in a normal noise electromagnetic environment, the first ground wiring NG1 and the second ground wiring NG2 may not be present.

Although shown in parentheses in FIG. 5, FIG. 5A shows the output signals of the third and fourth electrodes E33 and E43 when the touch position TP is touched, as in the first embodiment. FIG. 5B shows an example of the differential signal output from the differential amplifier 62 at that time.

Here, in FIG. 9, the touch position TP is closer to the third electrode E33 than to the fourth electrode E43. That is, between the resistance of the detection layer 31 between the third electrode E33 and the touch position TP (hereinafter referred to as the third resistance R33, the resistance value is referred to as _R33 ) and between the fourth electrode and the touch position TP. It is assumed that the relationship of R ₃₃ <R ₄₃ is established with the resistance of the detection layer 31 (hereinafter referred to as the fourth resistance R ₄₃ and the resistance value is described as R 43).

When a pulse signal is input to the third electrode E33 while the touch position TP is touched, a voltage corresponding to the time constant of the capacitance CT between the touched finger and the detection layer 31 and the third resistor _R33 . The touch position TP is charged up with. This charge-up state is reflected by the third electrode E33, and the reflected signal represented by the following equation (6) is input to one input terminal of the differential amplifier 62.

V ₃₃ = V _dd (1-exp ( _-t / R _33CT )) ... (6)

Here, the capacitance _CT is a value uniquely determined according to the material, thickness, and the like of the insulating protective layer. As shown in FIG. 4, a load Z2 having a specific value different for each user who touches is generated between the capacitance _CT and the ground. In order to facilitate the understanding of the invention, the influence thereof is omitted in this equation. The same applies to the following formula. In this disclosure, the load Z2 that differs for each user can be corrected by using a correction marker described later.

Similarly, when a pulse signal is input to the fourth electrode E43 while the touch position TP is touched, the other input of the differential amplifier 62 is input according to the time constants of the capacitance CT and the fourth resistor _R43 . The reflected signal represented by the following equation (7) is input to the terminal.

V ₄₃ = V _dd (1-exp (-t / R _{43 CT} )) ... (7)

Therefore, the differential amplifier 62 outputs the differential signal (the difference signal of the equations (6) and (7)) represented by the equation (8) below.

V _df = V ₃₃ -V ₄₃
= V _dd ( _-exp (-t / R ₃₃ CT) + exp (-t / R _{43 CT} )) ... (8)

When the differential signal is positive, the peak hold unit 64 holds the maximum voltage value of the equation (8) as the peak voltage, and when the differential signal is negative, the peak hold unit 64 holds the minimum voltage value of the equation (8) as the peak voltage. do.

The calculation unit 5 can obtain the touch position by calculation based on the peak voltage value, the sign information of the peak voltage, and the like.

-Selection of measurement electrode-
Next, the combination of electrodes selected as the measurement electrode from the pair electrodes will be specifically described.

FIG. 13A shows an example of deep learning learning data (weighted data) in which the combination of measurement electrodes is associated with the standard peak voltage of each detection region Q1, Q2, ..., Q80. In the following description, it may be referred to simply as weighted data. The weighted data exemplified in FIG. 13 (a) includes any plurality of individual features, hovering touch, and strongly finger-touched information. Since the principle of Eq. (8) is the same even if there is such a large difference in peak intensity, the acquired data have the same tendency and different relative values between the electrode combinations, so they are weighted by learning regardless of the touch environment. It has the feature that the value of and the convolution calculation value are automatically corrected.

Hereinafter, a specific description will be given with reference to FIGS. 15 to 19.

First, even in the two-point touch, the touch position can be detected based on the difference information from the measurement electrode to the touch position, as in the one-point touch. Specifically, the difference information that is the base of the two-point touch can be obtained by the following equation (4).

Difference information = (ab) + (cd) ... (9)

Here, a (first distance) is the distance between "one of the electrodes constituting the pair electrode" and "one of the touch positions of the two-point touch", and b (second distance) is "the other of the same electrodes". Is the distance between "" and "one of the same touch positions". Further, c (third distance) is the distance between "one of the electrodes constituting the pair electrode" and "the other of the two-point touch touch positions", and d (fourth distance) is "the other of the same electrodes". And "the other of the same touch positions".

15 and 16 show an example of the above-mentioned first to fourth distances a to d when a two-point touch is performed on a plan view showing a configuration example of a touch panel. FIG. 15 illustrates the case where the same-side pair electrode is selected as the measurement electrode, and FIG. 16 illustrates the case where the diagonal pair electrode is selected as the measurement electrode. FIG. 17 shows a state in which the detection area around the center of the conductive layer is touched at two points and moved in an oblique direction.

FIG. 18 shows a change in the output voltage of the peak hold unit 64 when the two-point touch and the shift operation of the touch position shown by the triangle mark in FIG. 13 are performed. Similarly, FIG. 19 shows a change in the output voltage of the peak hold unit 64 when the two-point touch and the shift operation of the touch position shown by the circles in FIG. 17 are performed. In each figure, Examples 1 and 2 show an example of same-edge acquisition, and a comparative example shows an example of diagonal acquisition. In the same-edge acquisition, a linear and large change is obtained in the difference information as the touch position changes. On the other hand, in the diagonal acquisition, even if the touch position changes, no significant change is observed in the difference information.

-Touch position detection operation-
In the following description, the operation of detecting the touch position by a method using deep learning learning will be specifically described. FIG. 10 shows the overall flow, and FIGS. 11 and 12 show the detailed flow of steps S2 and S6 of FIG. 6, respectively. Further, FIG. 13 shows an example of weighted data generated based on the random touch acquisition data after deep learning learning, and FIG. 14 shows an example of the calculation result of deep learning. Specifically, for example, data generated based on the detection result of random touch after data learning of 200 points × 5 = 1000 points for each of 5 different individuals for one position. Is. The deep learning method is a multi-layer perceptron.

In the deep learning method, individual differences in peak hold and differences in hovering distance are automatically corrected, and the location of one-point touch can be detected, but as mentioned above, the relative ratio between the electrode combinations does not change. Position can be detected.

In the case of two-point touch, the relative ratios are different as shown in FIGS. 11 and 12, so this is learned and detection is possible. The one-point touch can be detected by a specific pair of electrodes in the equation (8) in reality, and a plurality of combinations are performed in order to improve the detection accuracy. Moreover, they all show the same detection position. With 2-point touch and 3-point touch, locations with different detection positions appear. If you learn this difference, you can easily classify. This is a principle according to the equation (8), and in the case of Table 1, it is a perceptron of many electrode combinations, and the one-point and multi-point piecewise principles are connected and synthesized in the weighting of the multi-layer perceptron to determine. Will be done.

As shown in FIG. 13A, the deep learning learning data is associated with a combination of measurement electrodes and a standard peak voltage as standard output information for each detection region Q1, Q2, ..., Q80. It is listed in. In the present disclosure, the combinations of the measuring electrodes are different from each other, and the pulse signal is applied and measured for 100 combinations. Specifically, in the tables of FIGS. 13 and 14, different combinations of measurement electrodes are described for each column, and for convenience of explanation, electrode numbers P00 to P99 are attached to each combination of measurement electrodes. There is. Then, from the electrode numbers P00 to P05, the opposite side pair electrode is selected as the measurement electrode. Similarly, for electrode numbers P06 to P09, the same-side pair electrode is selected as the measurement electrode, and for electrode numbers P06 to P99, the diagonal pair electrode is selected as the measurement electrode.

In S1 of FIG. 10, the correction markers MK1 and MK2 (for example, the detection areas Q62 and Q19 of FIG. 15) are displayed on the touch panel 2 in response to the processing of the calculation unit 5. The correction marker is used to correct the standard difference information registered in the weighted data TB based on the touch operation by the user. The standard difference information includes the list information of the standard peak voltages of the detection regions Q1, Q2, ..., Q80 listed above. The display position and the number of display of the correction marker are not particularly limited.

In S2, the calculation unit 5 acquires no-touch correction data for correcting each standard peak voltage (hereinafter, also referred to as no-touch data) in the no-touch state before the user touches the touch panel 2.

FIG. 11 is a flow chart showing an example of the no-touch correction data acquisition operation. As shown in FIG. 11, first, the calculation unit 5 selects the measurement electrode according to a predetermined electrode selection rule (S21). The selection rule of the measurement electrode (for example, the combination of the measurement electrodes and the selection order) is registered in advance in the database stored in the storage unit 52 of the calculation unit 5, for example. Then, the calculation unit 5 selects the measurement electrodes in the order of the electrode numbers P00, P01, ..., P99 in the table of FIG. 13, for example. Specifically, in the example of FIG. 13, the calculation unit 5 selects the first electrode E11 and the third electrode E31 as the first measurement electrode.

Next, the calculation unit 5 supplies the electrode selection signal SC1 indicating the measurement electrode to the pulse generator 31 and the analog switch 32, and supplies a predetermined pulse signal to the pair electrodes E11 and E31 (S22). At this time, the arithmetic unit 5 also gives the same electrode selection signal SC1 to the analog switches 41 and 41. As a result, the output signals from the pair electrodes E11 and E31 to which the pulse signal is given are input to the differential amplifier 62, and the peak voltage is output from the peak hold unit 64. As a result, the calculation unit 5 acquires the peak voltage in the no-touch state from the peak hold unit 64 and registers it in the correction table TB1 (S23). After that, the arithmetic unit 5 discharges the pair electrodes E11 and E31 to which the pulse signal is given (S24). Discharge of the pair electrodes E11 and E31 is performed, for example, by short-circuiting the pair electrodes E11 and E31 to the ground.

In S25, it is determined whether or not the number of acquisitions of the peak voltage (combination of pair electrodes) has reached a specified number (for example, 1000 times), and if not (NO in S25), the process returns to S21 and the pair is paired. The combination of the electrodes E11 and E31 is changed to the pair electrodes E12 and E32 according to the next pair electrode number P02, and the peak voltage in the no-touch state is acquired. After that, the flow of S21 to S25 is repeated until the specified number of acquisitions of the peak voltage is reached. In this way, when the acquisition of the no-touch correction data is completed, the flow returns to S4 in FIG.

In S4 (marker correction processing) of FIG. 10, when any one of the correction markers MK1 and MK2 is touched (YES in S41), the calculation unit 5 acquires the marker correction data (S42). In S42, the same processing as that for acquiring the no-touch correction data in step S2 (FIG. 11) is performed, the marker touch correction data is acquired, and the marker touch correction data is registered in the correction table TB1. FIG. 13B shows an example in which the marker touch correction data of the markers MK1 and MK2 is acquired. After acquiring the marker touch correction data, the calculation unit 5 corrects the standard difference information using the marker touch correction data (S43). As shown in FIG. 12, which will be described later, when the weighted data TB2 is divided according to the number of touches, the same processing is performed for all the weighted data TBs.

As illustrated in FIG. 4 above, a load Z2 having a specific value different for each user who touches between the capacitance _CT at the touch position and the ground is generated. By using the marker touch correction data, it becomes possible to correct the calculation error caused by this load Z2.

When the correction of S43 is completed, the correction markers MK1 and MK2 are erased from the touch panel 2. Then, when the touch panel 2 is touched by the user (YES in S5), the calculation unit 5 performs a touch position detection calculation using the corrected and learned weighted data TB2 (S6).

Next, the touch position detection calculation by the calculation unit 5 will be described in detail with reference to FIG. In the touch position detection operation, the pair electrodes are selected according to the electrode selection rule, as in the case of acquiring the no-touch correction data (S60). Next, the calculation unit 5 gives an electrode selection signal SC1 to the pulse generator 31 and the analog switch 32, gives a predetermined pulse signal to the measurement electrode (S61), and peak-holds the peak voltage based on the output voltage from the measurement electrode. Obtained from unit 64 (S62).

In step S63, when the peak voltage is acquired, the arithmetic unit 5 separates the number of touches. Specifically, the peak voltage increases as the number of touches increases. Therefore, for example, a predetermined threshold value can be set, and the number of touches can be determined based on the relationship between the peak voltage and the threshold value.

In step S64, an estimation operation for estimating the position of the touch operation by the user is performed using the trained weighted data TB2 according to the number of touches separated in step S63 (S64). Here, it is assumed that it is determined to be a two-point touch in step S63.
Specifically, in the estimation operation,
(1) First, the arithmetic unit 5 compares the acquired peak voltage with the standard peak voltage in each detection region Q1, Q2, ..., Q80 of the learned weighted data TB2.
(2) Then, as shown in FIG. 14, "1" is used when the error between the two voltages described in (1) above is within the predetermined range, and "0" is set when the error between the two voltages exceeds the predetermined range. Is registered in the calculation result table TB3. For example, "1" is output when the error between the acquired peak voltage and the standard peak voltage is within ± 10%.

When the estimation calculation is completed, the pair electrode to which the pulse signal is given is discharged (S65). The candidate position in the present embodiment is a position where the error between the two voltages is within a predetermined range, that is, a position where "1" is registered in the calculation result table TB3.

Then, the arithmetic unit 5 repeats the processes of S61 to S65 until the specified number of acquisitions (for example, 100) is reached, and the pair electrode (for example, P00,) related to all the combinations specified in the electrode selection rule. The estimation calculation (calculation of (1) and (2) above) of P01, ..., P99) is performed.

After performing the estimation calculation a predetermined number of times (YES in S66), the calculation unit 5 performs a specific operation for determining the position of the touch operation by the user based on the result of the estimation calculation (S67). Specifically, the estimation calculation result is added for each detection area, and the position of the touch operation is determined based on the size, the degree of protrusion, the degree of approximation, and the like of the addition result. For example, in the example of FIG. 14, the addition result of the detection area Q36 is the largest at 80, followed by the addition result of the detection area Q45 at 75. Therefore, the calculation unit 5 determines that the two points of the detection areas Q36 and Q45 are the user's touch positions based on the number of extractions.

The method of determining the touch position in the specific operation is not particularly limited. For example, the judgment may be made based only on the magnitude of the addition value of the estimation calculation result for each detection region, or when there is a detection region in which the magnitude of the addition result is equal to or larger than a predetermined size and has a predetermined degree of protrusion. In addition, the detection area may be determined as the position of the touch operation. In addition, another evaluation axis based on a plurality of estimation calculation results and a plurality of peak voltage values is set, and the touch position is determined based on the result of the other evaluation axis or in consideration of the result of another evaluation axis. You may do so.

As described above, the inventors of the present application select a measurement electrode from the pair electrodes on the same side, apply the measurement signal to the measurement electrode, and acquire the output signal, which is significant even in the case of two-point touch. I found that it is possible to obtain various difference information. This makes it possible to detect a two-point touch with high accuracy in a patternless touch panel.

Further, as the measurement electrode, by combining the acquisition of the difference information from the same-side pair electrode and the acquisition of the difference information from the diagonal pair electrode and the opposite pair electrode, the one-point touch, the two-point touch and the multi-touch can be performed. Significant difference information can be obtained regardless of the touch position, and the touch position can be detected with higher accuracy.

Further, by using the electrodes on both outer sides of the electrode group E1 composed of three or more electrodes (for example, the first electrodes E11, E12, E13 in FIG. 3) as the measurement electrodes composed of the same side pair electrodes, the peak voltage can be measured. The difference can be increased. That is, it is possible to acquire highly significant difference information, whereby the touch position can be detected with higher accuracy. The same applies to the electrode group E2 consisting of the second electrodes E21, E22 and E23, the electrode group E3 consisting of the third electrodes E31, E32 and E33, and the E4 consisting of the fourth electrodes E41, E42 and E43.

Note that FIG. 3 shows an example in which three electrodes are provided on each side and one electrode group E1 to E4 is provided on each side, but the present invention is not limited to this. For example, the number of electrodes may be four or more, or two or more electrode groups may be provided. Specifically, for example, when six electrodes are provided on at least one side, the electrode group may be divided into two, and the electrodes on both outer sides of each electrode group may be used as measurement electrodes. Further, the electrodes constituting the electrode group may overlap.

Further, in the two-layer structure touch panel, the sheet resistance value needs to be in the range of 1 kΩ / □ to 5 kΩ / □ due to its characteristics, but in the present invention, the sheet resistance value of the conductive layer is two orders of magnitude higher. It is also characterized by its good points. That is, it is suitable for a large display, a large screen using a wall surface, and a large touch panel such as a large board surface such as a whiteboard. Further, since a sheet having a high sheet resistance value such as an organic conductive sheet or a metal thin film sheet can be applied to the conductive layer, it is also suitable for use on a curved surface.

<Other embodiments>
Although the embodiment of the present invention has been described above, various modifications can be made.

For example, in the first and second embodiments, the number of electrodes on each side is set to three, but the number of electrodes is not limited to this. The number of electrodes provided on each side may be at least two (at least one pair of electrodes), and the number of electrodes may be different on each side.

Further, in the first and second embodiments, the electrodes are provided along the sides of the conductive layer, but some electrodes may be provided at positions separated inward from the sides of the conductive layer. do not have. For example, when the opening area (effective touch area) of the touch panel 2 is smaller than the area of the detection layer 31, each electrode may be provided along a frame for partitioning the effective touch area of the touch panel 2. On the other hand, in order to secure a wide area where touch detection is possible in the conductive layer having the same area, it is preferable that electrodes are provided along the sides of the detection layer 31.

Further, in the second embodiment, the conductive layer has a rectangular shape, but the present invention is not limited to this. The conductive layer may have orthogonal and / or opposite sides, and the same effect as that of the second embodiment can be obtained. Specifically, a part of the conductive layer may be curved or a part of the conductive layer may be curved.

Further, in the second embodiment, an example in which the pulse signal is applied to the pair electrodes and the measurement is performed once for each combination of the pair electrodes is shown, but the electrodes constituting the pair electrodes are shown every 5 to 50 ms. The combination of the above may be changed, and the pulse signal application and measurement may be performed a plurality of times during this period of 5 to 50 ms. In this case, for example, the results of a plurality of measurements may be averaged and the value may be used for each calculation.

Further, in the above embodiment, the conductive layer is provided on the surface of the touch panel, but the conductive layer is provided at a position at a predetermined distance from the screen of the touch panel, for example, on the back side of a mobile phone. That is, the present invention can be applied even in a state where hovering is detected, and the same effect can be obtained. In this case, since the absolute value of the differential signal peak hold is small, for example, the magnification of the differential amplifier 62 may be increased to increase the output. Specifically, first, the presence / absence of touch is detected by the calculation unit 5 detecting the output from the peak hold unit 64 (after AD conversion by the ADC 65). Here, the calculation unit 5 can detect the touch operation if, for example, no-touch data having a level of the S / N ratio or higher is obtained. Since the calculation unit 5 also knows the output level from the peak hold unit 64, it can detect that there is a touch operation and at the same time recognize that it is hovering detection. Then, the calculation unit may perform the touch position detection calculation based on the set magnification of the differential amplifier 62 and the weighted data TB2 according to the hovering operation.

Further, in the above embodiment, the electrodes provided on each side of the detection layer 31 are assumed to be in symmetrical positions, but the electrodes on each side may be provided in asymmetrical positions. Specifically, as shown in FIG. 16, the distance from the first corner C1 of the conductive layer (upper left of FIG. 16) to the first electrodes E11, E12, and E13, and the fourth corner C4 of the conductive layer (upper right of FIG. 16). Each electrode may be arranged so that the distances from the third electrodes E31, E32, and E33 are different from each other. Similarly, the distance from the first corner C1 of the detection layer 31 to the fourth electrodes E41, E42, E43 and the second corner C2 of the detection layer 31 (lower left in FIG. 16) to the second electrodes E21, E22, E23. Each electrode may be arranged so that the distance between them is different from each other. That is, in FIG. 16, D21 ≠ D41 and D11 ≠ D31 may be satisfied. With such an asymmetric electrode configuration, it is possible to more effectively reduce the noise of the pulse signal applied from the pulse generator 31 to the measurement electrode and the output signal output from the measurement electrode to the differential amplifier 62. ..

INDUSTRIAL APPLICABILITY The present invention can realize a position detection device having a simple structure and high resolution, and is extremely useful for a touch panel used in various fields.

1 Position detection device 2 Touch panel (base)
22 Conductive layer 6 Position detector

Claims (4)

A base portion comprising a signal input node and a conductive layer having orthogonal and / or opposite sides and having at least two electrodes each at an intermediate position between the two sides.
A signal source that gives a measurement signal to the signal input node of the base unit,
Among the electrodes, an same-side pair electrode consisting of a pair of electrodes selected from the same side of the conductive layer, a diagonal pair electrode consisting of an electrode selected from each of the diagonal sides of the conductive layer, or a diagonal pair electrode. , The position of the object close to the conductive layer is calculated based on the difference information of the signal output to the measurement electrode selected from the facing pair electrode consisting of the electrodes selected one from each of the facing sides. Equipped with a position detector
The base portion is a conductive signal input uniformly formed in a detection region including a sheet-like substrate having an insulating property and a central portion on the back surface side of the substrate, and the signal input node is provided on a peripheral portion. The layer is provided with the conductive layer uniformly formed in the detection region on the surface side of the substrate.
A position detection device characterized by that. The position detection device according to claim 1, wherein the signal input node is connected to an electrode of the conductive layer. The position detection device according to claim 1, wherein the position detection unit uses at least two types of pair electrodes of the same side pair electrode, the diagonal pair electrode, or the opposite pair electrode as the measurement electrode. An electrode group composed of three or more electrodes is provided on at least one side of the conductive layer.
The position detection device according to claim 1, wherein when the same-side pair electrode is selected as the measurement electrode, the electrodes at both outer ends of the electrode group are selected.

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