JP2019159446A - Position detection device - Google Patents

Abstract

To highly accurately perform touch detection of not only one-point touch but also two-point touch in a patternless touch panel.SOLUTION: A position detection device 6 comprises a touch panel 2 serving as a base part provided with the same side pairs of electrodes at intermediate positions on respective sides of a rectangular detection layer 31, and a position detection unit 6. The position detection unit 6 applies a measurement signal to a first pair of electrodes selected from among the same side pairs of electrodes on the respective sides and calculates a position of an object approaching the detection layer 31 on the basis of difference information of an output signal from the first pair of electrodes.SELECTED DRAWING: Figure 1

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 includes a plurality of first electrodes arranged side by side on an insulating substrate, a plurality of second electrodes arranged side by side across the first electrode, and an insulation interposed between the two electrodes. When viewed in plan, 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).

JP 2010-146785 A JP 2008-134522 A JP 2013-250642 A

  In such a capacitive touch panel (hereinafter also referred to as a two-layer touch panel) using a patterned two-layer electrode pad, a relatively high touch detection accuracy can be realized, but the 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 position is calculated based on the output voltage of the detection circuit. In Patent Document 3, pulse signals having the same phase and voltage are applied to the four corner electrodes of the rectangular conductive film, and the touch position of the user is detected using a 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, the conventional technique such as Patent Document 2 has a problem that it is difficult to detect so-called two-point touch in which two different points on the touch panel are touched.

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

  A position detection device according to one embodiment 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 of at least two sides of the conductive layer. Selected from the same side of the conductive layer among the electrodes, propagated through the conductive layer from the signal input node, and a signal source for supplying a measurement signal to the signal input node of the base unit A pair of electrodes on the same side, a pair of electrodes selected from each of the diagonal sides of the conductive layer, or a pair of diagonal electrodes selected from each of the opposite sides of the conductive layer. A position detection unit that calculates the position of an object approaching the conductive layer based on difference information of the measurement signal output from a measurement electrode selected from a pair of opposed electrodes made of electrodes; And wherein the door.

  Here, in the “base portion including a conductive layer”, a conductive film is formed on a base member formed of an insulator, for example, a transparent insulating substrate, a resin casing of an electronic device, or the like. Including In addition, the base portion includes two conductive layers. In other words, the base portion is a conductive substrate having a sheet-like base having insulating properties and a detection region including a central portion on the back side of the base and the signal input node provided on the peripheral portion. A signal input layer and the conductive layer formed uniformly in the detection region on the surface side of the substrate may be provided.

  On the other hand, the conductive layer may be a single layer. In other words, the conductive layer includes a base member formed of an insulator and one layer of the conductive layer formed thereon, and a part or all of the substrate as the base portion is formed of the conductive layer. Is included. Furthermore, the case where the base part is composed of only one conductive layer is also included. In this case, the conductive layer includes all conductive layers in which a layer is formed. In addition to the conductive film, for example, a conductive film, a conductive sheet, and a conductive plate are also included. 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 counter pair electrode. Accordingly, the electrodes can be selected so that the relative positions of the measurement electrode and the touch position are different from each other. Therefore, the signal difference of the output signals from the measurement electrodes obtained by the position detection device can be increased, and sufficient touch detection sensitivity can be obtained. Here, the “touch” is a concept including both a direct touch on the display screen (contact with the display screen) and an indirect touch on the display screen (so-called hovering).

  The position detection unit may be configured to use at least two types of pair electrodes as the measurement electrode among the same-side pair electrode, the diagonal pair electrode, or the counter pair electrode.

  Thereby, sufficient sensitivity can be obtained by a signal difference due to a 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 difference information, and a two-point touch can be detected with high accuracy in addition to a one-point touch.

  According to the position detection method of 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 touchscreen which concerns on 1st Embodiment. It is sectional drawing which shows the structure of the touchscreen which concerns on 1st Embodiment. It is a figure for demonstrating the position detection principle of the touchscreen which concerns on 1st Embodiment. It is the figure which showed the example of a signal waveform when the point TP is 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 touchscreen which concerns on 2nd Embodiment. It is a top view which shows the structural example of the touchscreen which concerns on 2nd Embodiment. It is a figure for demonstrating the position detection principle of the touchscreen which concerns on 2nd Embodiment. It is a flowchart which shows an example of the detection method of the touch position which concerns on 2nd Embodiment. It is a flowchart which shows an example of the acquisition operation of no-touch correction data. It is a flowchart which shows an example of the detection calculation of a touch position. 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 touchscreen which concerns on 2nd Embodiment. It is a top view which shows the structural example of the touchscreen which concerns on 2nd Embodiment. It is a top view which shows the structural example of the touchscreen which concerns on 2nd Embodiment. It is a figure which shows the relationship between the touch position of two-point touch, and a peak voltage. It is a figure which shows the relationship between the touch position and peak voltage of two-point touch. It is a top view which shows the other structural example of a touchscreen. It is a top view which shows the other structural example of a touchscreen.

  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 merely illustrative in nature and is not intended to limit the present invention, its scope of application, or its use.

<First Embodiment>
FIG. 1 is a block diagram illustrating a configuration example of a position detection device 1 according to the present embodiment. 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 includes a conductive sheet 20 having a sheet-like (film-like or thin plate-like) base 21.

-Conductive sheet-
As shown in FIGS. 2 and 3, on the surface of the base 21, a detection layer 31 as a conductive layer, an insulating layer 32 and The ground layers 33 are uniformly formed and stacked. Similarly, the signal input layer 41 is uniformly formed on the back surface of the base 21 in the detection region Rd. The detection region Rd corresponds to a region for detecting a touch position when the conductive sheet 20 is used as a member of a patternless touch panel. In the present embodiment, for convenience of explanation, it is assumed that the surface of the base 21 faces the operator. Also, “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 base 21. That is, it is possible to cope with a touch operation from the back 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 a patternless touch panel, the base 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 base 21 according to the present embodiment includes a substrate 21a having a predetermined thickness, and an insulating film 21b bonded to the surface of the substrate 21a with an adhesive film (for example, an OCA (Optical Clear Adhesive) film).

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

  The thickness of the base 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. To the position detection unit 6 and the like. When the thickness of the base 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, A sufficient output signal may not be obtained. Specifically, the thickness of the substrate is preferably 0.8 mm or more and 6.8 mm or less.

  On the surface of the base 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 a touch position when the conductive sheet 20 is used as a member of a patternless touch panel. In other words, the conductive sheet 20 of the present invention is configured to be able to detect the presence or absence of a touch operation by the position detection unit 6 (see FIG. 8) by being mounted on the patternless touch panel. The detection layer 31 is uniform in a detection layer formation region R1 slightly wider than the detection region Rd from the viewpoint of avoiding the generation of capacitance between the electrode E and the output wiring 53 and the signal input layer 41 and the ground layer 33. It is desirable that it is formed. 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 portion), a plurality of electrodes E (corresponding to signal output nodes No.) are arranged at equal pitches at intermediate positions in the longitudinal direction of the sides spaced from the corners of the respective sides. Is formed. The number of electrodes E is equal to the number of output wirings 53 in the wiring area described later. FIG. 2 shows an example in which three electrodes E are provided on each side of the detection layer 31. In the present embodiment, “equal” only needs to be substantially equal, and the same effect can be obtained even if there is a slight misalignment. Therefore, “equal” is a concept including substantially equal in addition to being equal (completely matching).

  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 “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 a “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, antimony-doped tin oxide (ATO), polythiophene (PEDOT), One or more conductive materials selected from the group consisting of polyaniline and water-soluble sulfonated polyaniline are contained. The carbon is not particularly limited as long as it exhibits electrical conductivity. For example, carbon black, graphene, or carbon nanotube can be used.

  A plurality of output wirings 53 extending along the periphery of the detection layer 31 are formed in the wiring region Rw on the substrate surface. 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, the respective output wirings 53 are connected to the detection layer 31 via the electrodes E provided so as to be separated from each other, and the electrodes E function as signal output nodes. Each output wiring 53 is routed along the periphery of the detection layer 31, concentrated at one place (near the lower right corner in FIG. 2), and connected to different electrodes E. In this way, by consolidating the ends (electrodes) of the output wiring 53, 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 ground layer 33 is uniformly formed by lamination through an insulating layer 32. A signal input node Ni is provided at an intermediate position on the upper side (corresponding to the peripheral portion) of the ground layer 33 on the left side in the horizontal direction of the drawing. A second input wiring 52 that is 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 base 21. The signal input layer 41 is uniformly formed in the signal input layer formation region R3 having substantially the same area as the detection region Rd. The ground layer 33 and the signal input layer 41 are arranged so that their positions in the plan view in the conductive sheet 20 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 side in the horizontal direction of the drawing. A first input wiring 51 that is wider than the output wiring 53 is connected to the signal input node Ni. The 1st input wiring 51 and the 2nd input wiring 52 are arrange | positioned so that the mutual position in the planar view in the electrically conductive sheet 20 may become 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 upward in the drawing, and then along the periphery of the conductive sheet 20 in the right direction of the drawing and below the drawing. In an L shape toward the direction, it extends to an intermediate position in the vertical direction on the right side of the drawing.

  A pulse generator 71 of the position detection unit 6 to be described later is connected to the leading ends 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 through 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 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.

  In addition, as shown in FIG. 3, you may make it cover the surface of a grounding layer, and the back surface of the signal input layer 41 with an insulating cover layer. On the other hand, for example, when a space is provided before or after the conductive sheet 20, insulating parts are disposed, or when the periphery of 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 includes a pulse generator 71 (denoted as PG in FIG. 1). The pulse generator 71 generates a rectangular pulse signal (voltage: Vcc) that varies 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 (indicated as AS in FIG. 1), a differential amplifier 62, a noise filter 63, a peak hold unit 64, and an analog-to-digital conversion circuit 65 having the same configuration. (Referred to as ADC in FIG. 1).

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

  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 signal amount difference 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-digital conversion circuit 65 converts the peak voltage value and the sign information of the peak voltage into a digital value based on the peak voltage (analog signal).

  Combinations of measurement electrodes include 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 electrodes provided on any one side of the conductive layer. For example, the combination of the electrodes described in the column “Same-side acquisition” in FIG. included. The opposite-side pair electrode is a pair of electrodes selected one by one from the opposite sides, and includes, for example, combinations of electrodes described in the column “Opposite-side acquisition” in FIG. The diagonal pair electrode is a pair of electrodes selected one by one from the orthogonal sides, and includes, for example, combinations 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 transmits a timing-controlled input signal pulse and selects a measurement electrode from a pair of electrodes, and uses an electrode selection signal SC1 indicating the selected measurement electrode as an analog of the signal source 3 and the position information acquisition unit 60. Transmit to switches 61 and 61. Further, the calculation unit 5 determines the position of an object (for example, a user's finger) that approaches or touches the touch panel 2 based on the difference information included in the differential signal (digital value) output from the analog-digital conversion circuit 65. Calculate by calculation. Here, the difference information refers to all information obtained based on the differential signal. For example, the difference information includes sign 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. Time information etc. are included.

-Touch panel position detection principle-
Hereinafter, the detection principle of 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 diagram showing a state in which the pulse generator 71 and the differential amplifier 62 of the position detection unit 6 are connected to the conductive sheet 20 in the 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. The 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. 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.

  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 base 21 and is output as an output signal from the electrode E of the detection layer 31. The differential amplifier 62 is supplied with 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.

  Thereafter, the calculation of the touch position is performed by the calculation unit 5 connected to the subsequent stage.

  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 are respectively in accordance with the following formula (1). Output voltage.

  V = Vdd (1-exp (−t / RC)) (1)

C = C _T + C _S (2)

Here, Formula (2) has shown the value of C of Formula (1). In the formula (2), C _T is the capacitance between the sensing layer 31 and the touched finger, C _S is the internal volume of the conductive sheet 20 in the touch position TP. Incidentally, _{C S} is the value of Ct / Cs is desirably set to be 1 to 100.

  In addition, R in Equation (1) includes R1 and R2 which are resistance values between the measurement electrodes E1 and E2 and the touch position, and wiring resistance from the measurement electrodes E1 and E2 to the position detection device 6. The resistance component RZ of the impedance Z between the RL and 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 such an extent that there is almost no influence, the wiring resistance RL and the resistance component RZ are assumed to be “0 (zero)” in the following calculation.

Then, when the resistance between the one electrode E1 and the touch position TP of the measuring electrodes E1, E2 and R _1, the electrode E1, the voltage indicated by the following formula (3), respectively, are outputted.

V1 = Vdd (1-exp ( -t / R 1 C)) ‥ (3)

Similarly, when the resistance between the other electrode E2 and the touch position TP of the measuring electrodes E1, E2 and R _2, the electrode E2, the voltage indicated by the following formula (4), respectively, are outputted.

V2 = Vdd (1-exp ( -t / R 2 C)) ‥ (4)

  Therefore, the differential amplifier 62 outputs a differential signal (difference signal between the expressions (3) and (4)) shown in the following expression (5).

Vdf = V1-V2
_{= Vdd (-exp (-t / R} 1 C) + exp (-t / R 2 C)) ‥ (5)

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

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

  Note that 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 independent of the type of touch operation. The same. Similarly, when the touch position is one point (so-called one-point touch), when the touch position is two points (so-called two-point touch), and when the touch position is three points or more (so-called multi-touch), position detection is performed. Although the amplitude of the voltage detected by the unit 6 is different, 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 positions of the measurement electrode and the touch position are different. The electrodes can be selected to be a distance. Thereby, 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, the case where any one of the same side pair electrode, the diagonal pair electrode, or the counter pair electrode is selected as the measurement electrode has been described as an example. More preferably, at least two types of pair electrodes are used as measurement electrodes. By doing so, the relative positions of the measurement electrode and the touch position can be different distances. Thereby, 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 base 21 and uniformly forms a signal input layer 41 for supplying a measurement signal to the back side of the detection region Rd. The patternless touch panel is formed with the conductive sheet 20 formed uniformly with the detection layer 31 formed and formed with the signal output node No. for forming the measurement signal propagated through the base 21 on the surface side of the detection region Rd. It was found that the touch position can be detected 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. However, the present invention is not limited to this. For example, as shown in FIG. 20, the detection region Rd (the detection layer 31 and the signal input layer 41) may be elliptical, or a part of the detection region Rd (the detection layer 31 and the signal input layer 41) may be It may be curved or curved. Even if a part of the detection region Rd is curved or curved, the principle of detecting the touch position is the same as that in the above embodiment, and thus detailed description thereof is omitted here.

Second Embodiment
FIG. 6 is a block diagram illustrating a configuration example of the position detection apparatus 1 according to the present embodiment. In FIG. 6, the same reference numerals are given to blocks common to FIG. 1. In the following description, differences from 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 of the first embodiment. In the following description, for convenience of description, 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. The electrodes provided on each side in the counterclockwise order from the first electrode are referred to as second, third, and fourth electrodes, respectively. Further, the first electrode / third electrode may be described with reference numerals E11 / E31, E12 / E32, E13 / E33 in order from the top to the bottom in order to facilitate understanding of the description. is there. Similarly, the second electrode / fourth electrode may be described with reference numerals E21 / E41, E22 / E42, E23 / E43 in order from the right to the left in the drawing.

  6, the signal source 7 includes 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 varies 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 a configuration of the touch panel 2 according to the present embodiment, and FIG. 8 is a plan view thereof. In the present embodiment, the touch panel 2 includes a rigid substrate or a flexible sheet having electromagnetic transparency (including light and a touch electric field), and includes a rectangular base body 21 in a plan view. In the present disclosure, the rectangle is a concept including a square and a rectangle. On the surface of the substrate 21, an electromagnetically transmissive detection layer 31 is formed over substantially the entire surface, and a transparent insulating protective layer 23 is formed thereon. The detection layer 31 is an ITO (Indium Tin Oxide) film, for example, and has a resistance value of 1 kΩ / □ to 10 MΩ / □. The insulating protective layer 23 is, for example, a polyester sheet, and the thickness thereof 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 transmits a timing-controlled input signal pulse and selects a measurement electrode from a pair of electrodes, and uses an electrode selection signal SC1 indicating the selected measurement electrode as an analog of the signal source 3 and the position information acquisition unit 60. Transmit to switches 61 and 61. Furthermore, the calculation unit 5 determines the object (for example, a user's finger) that has approached or contacted the insulating protection layer 23 based on the difference information included in the differential signal (digital value) output from the analog-digital conversion circuit 65. The position is obtained by calculation. Here, the difference information refers to all information obtained based on the differential signal. For example, the difference information includes sign 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. Time information etc. are included. Further, the calculation unit 5 includes a ROM 51 in which programs for performing various controls are stored, a correction table TB1 described later, and a database necessary for deep learning (deep learning learning data, weighting after deep learning learning). Data and data necessary for the perceptron method) are stored. The definition of the measurement electrode is the same as that in the first embodiment, and a pair electrode to be measured arbitrarily selected from the electrodes E provided on the detection layer 31, that is, a pair of electrodes on the same side, a diagonal line It is a pair electrode arbitrarily selected from a pair electrode or a counter pair electrode.

-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. FIG. In the following description of the position detection principle, the pulse signal from the pulse generator 31 is applied to the third and fourth electrodes E33 and E43 as measurement electrodes, and the differential amplifier 62 outputs 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 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 by an input signal line NI via a reference resistor R0. 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 the 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 loads Z1 and Z1 is connected to the ground.

  FIG. 9 shows an example in which the input signal wiring NI is a pair wiring with the first ground wiring NG1 running along the wiring NI for the purpose of dealing 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 a pair wiring with a ground wiring (hereinafter referred to as a 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 (end portions on the touch panel side) of the first and second ground wirings NG1, NG2 are open ends. However, in the normal noise electromagnetic environment, the first ground wiring NG1 and the second ground wiring NG2 may not be provided.

  Although shown in parentheses in FIG. 5, as in the first embodiment, FIG. 5A shows output signals of the third and fourth electrodes E33 and E43 when the touch position TP is touched. 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 the fourth electrode E43. That is, the resistance of the sensing layer 31 between the third electrode E33 and the touch position TP (hereinafter, referred to as a third resistor R33, the resistance value is referred to as _{R 33)} 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 resistor R _43, and the resistance value is described as R ₄₃ ).

In a state where the touch position TP is touched, the pulse signal to the third electrode E33 is input, capacitance C _T and the voltage corresponding to the time constant of the third resistor R33 between the touched finger and the sensing layer 31 The touch position TP is charged up. This charge-up state is reflected by the third electrode E33, and a reflection signal represented by the following formula (6) is input to one input terminal of the differential amplifier 62.

V ₃₃ = V _dd (1-exp (−t / R ₃₃ C _T )) (6)

Here, the capacitance C _T, the material of the insulating protective layer is a value determined depending on the thickness and the like. As shown in FIG. 4, a load Z2 having a specific value that differs for each touching user is generated between the capacitor _CT and the ground. In order to facilitate understanding of the invention, the influence is omitted in this equation. The same applies to the following equations. In the present disclosure, the load Z2 that is different for each user can be corrected using a correction marker described later.

Similarly, in a state where the touch position TP is touched, the pulse signal to the fourth electrode E43 is input, depending on the time constant of the capacitor C _T and the fourth resistor R43, the other input of the differential amplifier 62 A reflected signal represented by the following formula (7) is input to the terminal.

V ₄₃ = V _dd (1-exp (−t / R ₄₃ C _T )) (7)

  Therefore, the differential amplifier 62 outputs a differential signal (a difference signal between the equations (6) and (7)) shown in the following equation (8).

V _df = V ₃₃ −V ₄₃
= V _dd (−exp (−t / R ₃₃ C _T ) + exp (−t / R ₄₃ C _T )) (8)

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

  In the calculating part 5, a touch position can be calculated | required by calculation based on the peak voltage value, the code | symbol information of a peak voltage, etc.

-Selection of measurement electrode-
Next, the combination of the electrodes selected from the pair electrodes as the measurement electrode 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 voltages of the detection regions Q1, Q2,..., Q80. In the following description, it may be simply called weighted data. The weighting data illustrated in FIG. 13A includes arbitrary plural individual features, information on a hovering touch and a strong finger touch. Even if there is a large difference in peak intensity, the principle of equation (8) is the same, so the acquired data is weighted by learning regardless of the touch environment because the relative values between the electrode combinations differ with the same tendency. And the convolution calculation value are automatically corrected.

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

  First, also 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 electrodes” ”And“ one of the touch positions ”. Further, c (third distance) is a distance between “one of the electrodes constituting the pair electrode” and “the other of the touch positions of the two-point touch”, and d (fourth distance) is “the other of the electrodes”. And “the other of the touch positions”.

  15 and 16 show examples of the first to fourth distances a to d when a two-point touch is performed on a plan view showing a configuration example of the touch panel. FIG. 15 illustrates the case where the same 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 where two detection areas around the center of the conductive layer are touched 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 touch position shift operation indicated 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 indicated by the circle in FIG. 17 and the shift operation of the touch position are performed. In each figure, Examples 1 and 2 show an example of acquisition of the same side, and the comparative example shows an example of diagonal acquisition. In the same-side 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, an operation for detecting a touch position by a technique using deep learning learning will be specifically described. FIG. 10 shows the overall flow, and FIGS. 11 and 12 show detailed flows of steps S2 and S6 in FIG. 6, respectively. FIG. 13 illustrates an example of weighting data generated based on random touch acquisition data after deep learning learning, and FIG. 14 illustrates an example of a deep learning calculation result. Specifically, for example, data generated based on the detection result of random touch after performing data learning of 200 points × 5 = 1000 points for five different individuals with respect to the position of one point It is. The deep learning method is a multilayer perceptron.

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

  In the case of two-point touch, the relative ratios are different as shown in FIGS. 11 and 12, and this is learned to enable detection. One-point touch can actually be detected by a specific pair of electrodes in accordance with Equation (8), and a plurality of combinations are performed in order to increase detection accuracy. Moreover, they all indicate the same detection position. In the two-point touch and the three-point touch, a place with a different detection position appears. If this difference is learned, the classification can be easily performed. This is the principle according to equation (8). In Table 1, the perceptron is a combination of many electrodes, and the one-point and multi-point piecewise principles are combined and synthesized in the weighting of the multilayer perceptron. Is done.

  As shown in FIG. 13 (a), the learning data of deep learning is associated with a combination of measurement electrodes and standard peak voltages as standard output information of each detection region Q1, Q2,. Are listed. In the present disclosure, pulse signal application and measurement are performed for 100 combinations with different combinations of measurement electrodes. Specifically, in the tables of FIG. 13 and FIG. 14, different combinations of measurement electrodes are described for each column, and for convenience of explanation, electrode numbers P00 to P99 are given to the respective combinations of measurement electrodes. Yes. And from electrode number P00 to P05, the opposite side pair electrode is selected as a measurement electrode. Similarly, for electrode numbers P06 to P09, the same pair electrodes are selected as measurement electrodes, and for electrode numbers P06 to P99, diagonal pair electrodes are selected as measurement electrodes.

  In S <b> 1 of FIG. 10, correction markers MK <b> 1 and MK <b> 2 (for example, detection areas Q <b> 62 and Q <b> 19 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 weighting data TB based on the touch operation by the user. The standard difference information includes list information of standard peak voltages of the detection areas Q1, Q2,..., Q80 listed above. Note that the display position and number of correction markers are not particularly limited.

  In S <b> 2, the calculation unit 5 acquires no-touch correction data for correcting each standard peak voltage (hereinafter also referred to as no-touch data) in a no-touch state before the user performs a touch operation on the touch panel 2.

  FIG. 11 is a flowchart showing an example of an operation for acquiring no-touch correction data. As shown in FIG. 11, the calculating part 5 first selects a measurement electrode according to a predetermined electrode selection rule (S21). Measurement electrode selection rules (for example, combinations and selection order of measurement electrodes) are registered in advance in a database stored in the storage unit 52 of the calculation unit 5, for example. And the calculating part 5 selects a measurement electrode in order of the electrode numbers P00, P01, ..., P99 of the table | surface 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 an electrode selection signal SC1 indicating a 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 gives the same electrode selection signal SC1 to the analog switches 41 and 41 as well. As a result, the output signals from the pair electrodes E11 and E31 to which the pulse signal is applied are input to the differential amplifier 62, and the peak voltage is output from the peak hold unit 64. Thereby, the calculating part 5 acquires the peak voltage in a no-touch state from the peak hold part 64, and registers it in correction table TB1 (S23). Thereafter, the calculation unit 5 discharges the pair electrodes E11 and E31 to which the pulse signal is given (S24). The pair electrodes E11 and E31 are discharged by, for example, short-circuiting the pair electrodes E11 and E31 to the ground.

  In S25, it is determined whether or not the number of peak voltage acquisitions (pair electrode combination) has reached a specified number (for example, 1000 times). If not (NO in S25), the process returns to S21, The combination of the electrodes E11 and E31 is changed to the pair electrodes E12 and E32 related to the next pair electrode number P02, and the peak voltage in the no-touch state is acquired. Thereafter, the flow of S21 to S25 is repeated until the specified number of peak voltage acquisition times 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) in FIG. 10, when any one of the correction markers MK1 and MK2 is touched (YES in S41), the calculation unit 5 acquires marker correction data (S42). In S42, processing similar to the processing related to acquisition of no-touch correction data in step S2 (FIG. 11) is performed, marker touch correction data is acquired, and registered in the correction table TB1. FIG. 13B shows an example in which marker touch correction data for 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 described later, when the weighting data TB2 is divided according to the number of touches, the same processing is performed for all the weighting data TB.

Incidentally, as illustrated in Figure 4 above, the load Z2 specific value that is different for each person who touches between the capacitance C _T and the ground of the touch position occurs. By using the marker touch correction data, it is possible to correct a calculation error caused by the load Z2.

  When the correction of S43 is completed, the correction markers MK1 and MK2 are deleted from the touch panel 2. When the touch operation by the user is received on the touch panel 2 (YES in S5), the calculation unit 5 performs a touch position detection calculation using the corrected weighted data TB2 that has been corrected (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 calculation, a pair electrode is selected in accordance with the electrode selection rule as in the case of obtaining no-touch correction data (S60). Next, the calculation unit 5 gives the 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 holds the peak voltage based on the output voltage from the measurement electrode. Obtained from the unit 64 (S62).

  In step S63, when the peak voltage is acquired, the calculation 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 is provided, 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 calculation for estimating the position of the touch operation by the user is performed using the learned weight data TB2 corresponding to the number of touches separated in step S63 (S64). Here, it is assumed that a two-point touch is determined in step S63.
Specifically, in the estimation calculation,
(1) First, the computing unit 5 compares the acquired peak voltage with the standard peak voltage in each of the detection regions Q1, Q2,..., Q80 of the learned weighted data TB2.
(2) Then, as shown in FIG. 14, "1" is obtained when the error between both voltages described in (1) is within a predetermined range, and "0" when the error between both voltages exceeds a 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 above-described error between both voltages is within a predetermined range, that is, a position where “1” is registered in the calculation result table TB3.

  And the calculating part 5 repeats the process of said S61-S65 until it reaches | attains the prescribed | regulated acquisition frequency (for example, 100), and the pair electrode (for example, P00, P) concerning all the combinations prescribed | regulated by the electrode selection rule P01,..., P99) estimation calculation (calculations (1) and (2) above) is performed.

  After performing the estimation calculation a predetermined number of times (YES in S66), the calculation unit 5 performs a specific calculation that determines 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 region, and the position of the touch operation is determined based on the size, the protrusion degree, the approximation degree, and the like of the addition result. For example, in the example of FIG. 14, the addition result of the detection region Q36 is the largest with 80, and then the addition result of the detection region Q45 is the largest with 75. Therefore, the calculation unit 5 determines that two points of the detection areas Q36 and Q45 are the touch positions of the user based on the number of extractions.

  Note that the method for determining the touch position in the specific calculation is not particularly limited. For example, determination may be made based only on the magnitude of the addition value of the estimation calculation result for each detection area, or when there is a detection area where the magnitude of the addition result is equal to or greater 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. Further, 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 with the result of another evaluation axis. You may do it.

  As described above, the inventors of the present application select a measurement electrode from the pair of electrodes on the same side, apply a measurement signal to the measurement electrode, and acquire an output signal. I found that I could get the difference information. Thereby, it is possible to detect a two-point touch with high accuracy in a patternless touch panel.

  In addition, as a measurement electrode, by combining the acquisition of difference information from the same pair electrode and the acquisition of difference information from the diagonal pair electrode or the counter pair electrode, in one-point touch, two-point touch and multi-touch, Significant difference information can be obtained regardless of the touch position, and the touch position can be detected with higher accuracy.

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

  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. However, the present invention is not limited to this. For example, four or more electrodes may be provided, 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. Furthermore, the electrodes constituting the electrode group may overlap.

  Furthermore, 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. However, in the present invention, the sheet resistance value of the conductive layer is higher by two digits or more. There is also a feature in the good point. That is, it is suitable for a large touch panel such as a large display, a large screen using a wall surface, a large plate surface such as a white board. Furthermore, 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>
While the embodiments of the present invention have been described above, various modifications can be made.

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

  In the first and second embodiments, the electrodes are provided along the sides of the conductive layer. However, some electrodes may be provided at positions separated from the sides of the conductive layer. Absent. 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 that partitions the effective touch area of the touch panel 2. On the other hand, it is preferable that electrodes be provided along the sides of the detection layer 31 in order to ensure a wide area where touch detection is possible in the conductive layer having the same area.

  Moreover, in the said 2nd Embodiment, although the conductive layer shall be rectangular shape, it is not limited to this. The conductive layer only needs to have orthogonal and / or opposing sides, and the same effect as in the second embodiment can be obtained. Specifically, a part of the conductive layer may be a curve, or a part of the conductive layer may be curved.

  In the second embodiment, the pulse signal is applied to the pair electrodes and the measurement is performed once for each combination of the pair electrodes. However, the electrodes constituting the pair electrodes every period of 5 to 50 ms. The pulse signal application and measurement may be performed a plurality of times during the period of 5 to 50 ms. In this case, for example, a plurality of measurement results may be averaged and used for each calculation.

  In the above embodiment, the conductive layer is provided on the surface of the touch panel. For example, the conductive layer is provided at a position spaced apart from the screen of the touch panel, such as the back side of the mobile phone. Even in a state where hovering is detected, the present invention can be applied 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 output 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 a touch operation if, for example, no-touch data having an S / N ratio level or higher is obtained. And since the calculating part 5 grasps | ascertains the output level from the peak hold part 64, it can recognize that it is a hovering detection simultaneously with detecting that there exists a touch operation. Then, the calculation unit may perform the touch position detection calculation based on the set magnification of the differential amplifier 62 and the weighting data TB2 corresponding to the hovering operation.

  Moreover, in the said embodiment, although the electrode provided in each edge | side of the detection layer 31 shall be a symmetrical position, the electrode of each edge | side may be provided in the asymmetrical position. Specifically, as shown in FIG. 16, the distance from the first corner C1 of the conductive layer (upper left of FIG. 16) to each of the first electrodes E11, E12, E13, and the fourth corner C4 of the conductive layer (upper right of FIG. 16). The electrodes may be arranged such 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 each of the fourth electrodes E41, E42, E43 and the second corner C2 of the detection layer 31 (lower left in FIG. 16) to each of the second electrodes E21, E22, E23. The electrodes may be arranged so that their distances are different from each other. That is, in FIG. 16, D21 ≠ D41 and D11 ≠ D31 may be satisfied. With this 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. .

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

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

Claims (5)

A base part comprising a signal input node and a conductive layer having orthogonal and / or opposite sides and at least two electrodes provided at intermediate positions of at least two sides;
A signal source for providing a measurement signal to the signal input node of the base unit;
Of the electrodes, a pair of electrodes on the same side comprising a pair of electrodes selected from the same side of the conductive layer, a pair of diagonal electrodes comprising one electrode selected from each of the diagonal sides of the conductive layer, or The position of the object approaching the conductive layer is calculated based on the difference information of the signal output to the measurement electrode selected from the counter pair electrode composed of one electrode selected from each of the opposite sides. A position detection device comprising a position detection unit that performs the above operation. The base portion is a conductive signal input formed uniformly in a detection region including an insulating sheet-like base and a central portion on the back side of the base, and the signal input node is provided at a peripheral portion. The position detecting device according to claim 1, further comprising: a layer and the conductive layer formed uniformly in the detection region on the surface side of the substrate. 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 electrodes, the diagonal pair electrodes, or the counter pair electrodes as the measurement electrodes. At least one side of the conductive layer is provided with an electrode group composed of three or more electrodes,
The position detection apparatus according to claim 1, wherein when the pair of electrodes on the same side is selected as the measurement electrode, the electrodes at both outer ends of the electrode group are selected.

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