Detection device

Abstract

A detection device according to an embodiment of the present invention comprises: a sensor substrate 12 having a first sensor layer 22A that includes a plurality of first sensor electrodes SX1 and a plurality of first wirings WL1 connected to the plurality of first sensor electrodes, and a second sensor layer 22B that includes a plurality of second sensor electrodes SX2 and a plurality of second wirings WL2 connected to the plurality of second sensor electrodes and that is provided opposite the first sensor layer 22A; and a controller 14 having a first detection circuit that supplies a drive signal to the plurality of first sensor electrodes through the plurality of first wirings, and that acquires and processes detection signals outputted from the first sensor electrodes, and a second detection circuit that supplies a drive signal to the plurality of second sensor electrodes through the plurality of second wirings, and that acquires and processes detection signals outputted from the second sensor electrodes.

Description

Detection device

[0001] Embodiments of the present invention relate to a detection device.

[0002] As non-contact detection devices, capacitive sensors or hover sensors are known. Usually, when a hover sensor is installed inside a wall, it can only be operated from one side. Also, when a hover sensor is attached to an acrylic partition or the like, it cannot be operated from both sides. By removing the shield layer of the hover sensor, it becomes possible to operate from both sides, but in this case, it becomes difficult to determine from which side the operation was performed.

[0003] Japanese Unexamined Patent Application Publication No. 2024-21759, Japanese Unexamined Patent Application Publication No. 2023-55127

[0004] An object of an embodiment of this invention is to provide a detection device capable of operating and detecting from both sides.

[0005] The detection device according to the embodiment includes a first sensor layer including a plurality of first sensor electrodes and a plurality of first wirings connected to the plurality of first sensor electrodes, and a plurality of second sensor electrodes and a plurality of second wirings connected to the plurality of second sensor electrodes, and a second sensor layer provided facing the first sensor layer, a sensor substrate having; A first detection circuit that supplies a drive signal to the plurality of first sensor electrodes via the plurality of first wirings, acquires and processes a detection signal output from the first sensor electrodes, and supplies a drive signal to the plurality of second sensor electrodes via the plurality of second wirings, and a second detection circuit that acquires and processes a detection signal output from the second sensor electrodes, and a controller having; is provided.

[0006] Figure 1 is a perspective view showing a hover detection device according to the first embodiment. Figure 2 is an exploded perspective view showing the sensor substrate of the hover detection device in disassembled form. Figure 3 is a schematic plan view showing the first sensor electrode layer of the sensor substrate. Figure 4 is a schematic plan view showing the base substrate and the first wiring / shield electrode layer of the sensor substrate. Figure 5 is a schematic plan view showing the base substrate and the second wiring / shield electrode layer of the sensor substrate. Figure 6 is a schematic plan view showing the second sensor electrode layer of the sensor substrate. Figure 7 is a cross-sectional view of the sensor substrate along line A-A in Figure 1. Figure 8 is a cross-sectional view of the sensor substrate along line B-B in Figure 1. Figure 9 is a block diagram showing an example of the schematic configuration of the hover detection device. Figure 10 is a flowchart showing an example of the hover detection operation in the hover detection device 10. Figure 11 is a flowchart showing a part of the hover detection operation in the hover detection device according to the second embodiment. Figure 12 is a timing chart showing an example of the operation of a frequency-hopping capable hover detection device according to the first embodiment. Figure 13 is a block diagram showing an example of the schematic configuration of a hover detection device according to the second embodiment. Figure 14 is a timing chart showing an example of the operation of the hover detection device 10 according to the second embodiment. Figure 15 is a schematic plan view showing the first sensor layer and the second sensor layer of the hover detection device according to the first modified example. Figure 16 is a cross-sectional view of the hover detection device according to the second modified example. Figure 17 is a plan view of the hover detection device according to the second modified example. Figure 18 is a cross-sectional view of the hover detection device according to the third modified example. Figure 19 is (a) a side view of the hover detection device according to the fourth modified example, and (b) a cross-sectional view of the sensor substrate. Figure 20 is (a) a side view of the hover detection device according to the fifth modified example, and (b) a cross-sectional view of the sensor substrate. Figure 21 is a plan view showing (a) the first sensor electrode layer and (b) the shield electrode layer of the hover detection device according to the fifth modified example. Figure 22 is a cross-sectional view of the sensor substrate of the hover detection device according to the sixth modified example. Figure 23 is a plan view of the hover detection device according to the third embodiment. Figure 24 is a cross-sectional view of the hover detection device according to the third embodiment. Figure 25 is a plan view showing (a) the first sensor electrode layer and (b) the second sensor electrode layer of the hover detection device according to the third embodiment. Figure 26 is a schematic diagram showing the connection relationship when the analog switch is switched. Figure 27 is a flowchart showing an example of the detection operation of the hover detection device according to the third embodiment.Figure 28 is a timing chart showing an example of the operation of the hover detection device 10 according to the third embodiment. Figure 29 is a cross-sectional view of the hover detection device according to the seventh modified example. Figure 30 is a plan view of the hover detection device according to the eighth modified example. Figure 31 is a cross-sectional view of the hover detection device according to the eighth modified example. Figure 32 is a plan view showing (a) the first sensor electrode layer and (b) the second sensor electrode layer of the hover detection device according to the eighth modified example. Figure 33 is a plan view showing (a) the first sensor electrode layer and (b) the second sensor electrode layer of the hover detection device according to the ninth modified example. Figure 34 is a cross-sectional view of the hover detection device according to the ninth modified example. Figure 35 is a cross-sectional view of the hover detection device according to the tenth modified example.

[0007] Embodiments of this invention will be described in detail below with reference to the drawings. Note that the disclosure is merely an example, and modifications that are easily conceivable by those skilled in the art while maintaining the spirit of the disclosure are naturally included within the scope of this disclosure. Furthermore, in order to clarify the explanation, the drawings may schematically represent the width, thickness, shape, etc., of each part compared to the actual embodiment, but these are merely examples and do not limit the interpretation of this disclosure. In addition, in this specification and in each drawing, elements similar to those described above in previously shown drawings are denoted by the same reference numerals, and detailed explanations may be omitted as appropriate.

[0008] (First Embodiment) As an example of a detection device, a double-sided hover detection device (sometimes referred to as a hover sensor) according to the first embodiment will be described in detail. Figure 1 is a perspective view of the hover detection device according to the first embodiment.

[0009] As shown in Figure 1, the hover detection device 10 comprises a sensor substrate 12, a detection circuit board 14 constituting a controller, and an external control device (host computer) 16. The sensor substrate 12 comprises, for example, a rectangular base substrate (core material) 20, a first sensor layer 22A provided on the side of the first main surface of the base substrate 20, and a second sensor layer 22B provided on the side of the second main surface of the base substrate 20 facing the first main surface.

[0010] The detection circuit board 14 is electrically connected to the sensor board 12 via wiring, for example, a flexible printed circuit board (FPC) 18. The detection circuit board 14 comprises a printed circuit board 15 and a plurality of electronic components or semiconductor elements mounted on the printed circuit board 15. In one example, the detection circuit board 14 includes a semiconductor element SD1 that constitutes an AFE circuit 24 that performs hover detection based on a detection signal from the sensor board 12, and a semiconductor element SD2 that constitutes a control circuit 25 that controls the hover detection operation in the AFE circuit 24. The AFE circuit (sometimes referred to as the detection circuit) 24 is, for example, an analog front end (AFE) circuit. The control circuit 25 includes, for example, an MCU (Micro Control Unit).

[0011] The external control device 16 is a device that functions as the host computer (host) of the hover detection device 10 according to this embodiment. The detection circuit board 14 is connected to the external control device (host) 16 via wiring, for example, a flexible printed circuit board (FPC) 17. The external control device (host) 16 can be any terminal capable of receiving hover operations in the hover detection device 10.

[0012] In the following explanation, one direction in the plane parallel to the sensor substrate 12 is referred to as the first direction X, one direction in the plane parallel to the sensor substrate 12 that is perpendicular to the first direction X is referred to as the second direction Y, and the direction perpendicular to both the first direction X and the second direction Y, as well as the normal direction to the main surface of the sensor substrate 12, is referred to as the third direction Z. Note that the second direction Y may intersect the first direction X without being perpendicular to it. Also, "plan view" refers to the view of the sensor substrate 12 from a direction perpendicular to the main surface.

[0013] Figure 2 is an exploded perspective view of the sensor substrate 12. Figures 3, 4, 5, and 6 are schematic plan views showing the first sensor electrode layer, first shield electrode layer, second shield electrode layer, and second sensor electrode layer of the sensor substrate, respectively. Figure 7 is a cross-sectional view of the sensor substrate along line A-A in Figure 1.

[0014] As shown in Figure 2, the sensor substrate 12 has a rectangular base substrate 20 that functions as a core material. The base substrate 20 is not limited to a rectangular shape, but in this embodiment, it is a rectangular base substrate having sides along a first direction X and a second direction Y. The base substrate 20 has a rectangular first main surface S1 and a rectangular second main surface S2 facing the first main surface S1. The base substrate 20 is an insulating substrate, and for example, a glass substrate, a glass epoxy substrate, etc., can be used. The base substrate 20 is not limited to a rigid substrate, but may be a flexible substrate. The base substrate 20 may be made of an insulating material that can transmit visible light.

[0015] According to this embodiment, the first sensor layer 22A provided on the first main surface S1 side of the base substrate 20 includes a first shield electrode layer SL1 laminated on the first main surface S1, a first sensor electrode layer SE1 laminated on the first shield electrode layer SL1, and a first surface protection layer PL1. The second sensor layer 22B provided on the second main surface S2 side includes a second shield electrode layer SL2 laminated on the second main surface S2, a second sensor electrode layer SE2 laminated on the second shield electrode layer SL2, and a second surface protection layer PL2. The first sensor layer 22A is a capacitive sensor array that detects the approach or contact of an object to be detected toward the first main surface S1 side. The second sensor layer 22B is a capacitive sensor array that detects the approach or contact of an object to be detected toward the second main surface S2 side.

[0016] As shown in Figures 2 and 4, in the first sensor layer 22A, the first shield electrode layer SL1 includes a conductive layer, for example, copper foil, laminated on the first main surface S1, and a first insulating layer IL1 (see Figure 7) laminated on the first main surface S1 on top of the conductive layer. The first shield electrode layer SL1 is formed by patterning the conductive layer. The first shield electrode layer SL1 includes a frame-shaped peripheral shield electrode 26a extending along the periphery of the first main surface S1, a plurality of first shield electrodes 27a extending in a second direction Y from one side of the peripheral shield electrode 26a to the vicinity of the other opposing side, a plurality of first wirings WL1, and a plurality of first connection terminals CT1. The plurality of first shield electrodes 27a are arranged at intervals in a first direction X. The plurality of first shield electrodes 27a are electrically connected to each other via the peripheral shield electrode 26a.

[0017] As shown in Figure 4, each first shield electrode 27a is formed in a shape that gradually narrows in width from one side to the other side of the surrounding shield electrode 26a. In one example, in a plan view, one side edge (right edge) of each first shield electrode 27a extends in the second direction Y, and the other side edge (left edge) extends in a direction inclined with respect to the second direction Y. As a result, the gap between multiple first shield electrodes 27a gradually widens in width from one side to the other side of the surrounding shield electrode 26a.

[0018] In this embodiment, the first shield electrode layer SL1 includes a plurality of first wirings WL1 and a plurality of first connection terminals CT1. That is, a plurality of first wirings WL1 and a plurality of first connection terminals CT1 are provided on the first main surface S1. Multiple first wirings WL1 are arranged in the gap between the peripheral shield electrode 26a and the first shield electrode 27a, and in the gap between two adjacent first shield electrodes 27a in the first direction X. The number of first wirings WL1 corresponds to the number of first sensor electrodes, which will be described later. The plurality of first connection terminals CT1 are provided along one side edge of the first main surface S1 and are arranged at intervals in the first direction X.

[0019] Multiple first wirings WL1 each extend in the second direction Y and are arranged substantially parallel to one another. One end of each first wiring WL1 is located near the first shield electrode 27a, and the other end is connected to the first connection terminal CT1. Each of the multiple first wirings WL1 is electrically isolated from the first shield electrode 27a. The first insulating layer IL1 is laminated on the first main surface S1, superimposed on the conductive layer. The first insulating layer IL1 covers the surrounding shield electrode 26a, the first shield electrode 27a, and the first wirings WL1, except for the first connection terminal CT1. The first insulating layer IL1 can be made of a light-transmitting insulating material, such as a resin material such as polyimide, vinyl resin, or polycarbonate.

[0020] As shown in Figures 2 and 3, a first sensor electrode layer SE1 is laminated on the first main surface S1, superimposed on the first shield electrode layer SL1. The first sensor electrode layer SE1 includes a plurality of first sensor electrodes PX1 and peripheral electrodes AX1 formed by patterning a conductive layer laminated on the first insulating layer IL1. The first sensor electrode layer SE1 has a rectangular detection region SA and a peripheral region (non-detection region) BE located around the detection region SA.

[0021] Multiple first sensor electrodes PX1 are provided in the detection region SA. The multiple first sensor electrodes PX1 are arranged in a matrix along the first direction X and the second direction Y. For example, if the first direction X is the row and the second direction is the column, the first sensor electrodes are arranged in a 9x11 matrix. Each first sensor electrode PX1 is, in one example, composed of a rectangular planar pattern. The peripheral electrode AX1 is provided in the peripheral region BE. The peripheral electrode AX1 extends along the four sides of the detection region SA and surrounds the first sensor electrodes PX1. The multiple first sensor electrodes PX1 are electrically independent of each other and are also electrically independent of the peripheral electrode AX1.

[0022] The first sensor electrode PX1 is formed of a metal such as titanium, molybdenum, or copper, or an alloy containing one or more of these metals. The first sensor electrode PX1 may also be formed of a translucent conductive material such as indium-tin mixed oxide (ITO) or indium-zinc mixed oxide (IZO). The surrounding electrode AX1 may be formed of the same material as the first sensor electrode PX1, or it may be formed of a different metal material than the first sensor electrode PX1.

[0023] The first surface protection layer PL1 is an insulating protective layer and is laminated over the entire surface of the first insulating layer IL1, overlapping the first sensor electrode PX1 and the surrounding electrode AX1. In one example, solder resist can be used as the first surface protection layer PL1. The first surface protection layer PL1 is not limited to this and may be formed from polymer materials such as quartz, polyimide, or polycarbonate.

[0024] On the other hand, as shown in Figures 1 and 2, the second sensor layer 22B provided on the second main surface S2 side of the base substrate 20 includes a second shield electrode layer SL2, a second sensor electrode layer SE2, and a second surface protection layer PL2, which are laminated on the second main surface S2.

[0025] As shown in Figure 5, the second shield electrode layer SL2 includes a conductive layer laminated on the second main surface S2 and a second insulating layer IL2 (see Figure 7) laminated on the second main surface S2 on top of the conductive layer. The second shield electrode layer SL2 has a peripheral shield electrode 26b formed by patterning a conductive layer, for example, copper foil, and a plurality of second shield electrodes 27b. The peripheral shield electrode 26b forms a frame shape extending along the periphery of the second main surface S2. The plurality of second shield electrodes 27b extend in a second direction Y from one side of the peripheral shield electrode 26b to the vicinity of the opposite side. The plurality of second shield electrodes 27b are arranged at intervals in a first direction X. The plurality of second shield electrodes 27b are electrically connected to each other via the peripheral shield electrode 26b.

[0026] Each second shield electrode 27b is formed in a shape that gradually narrows in width from one side to the other of the surrounding shield electrode 26b. In one example, in a plan view, one side edge (left edge) of each second shield electrode 27b extends in the second direction Y, and the other side edge (right edge) extends in a direction inclined with respect to the second direction Y. As a result, the gap between multiple second shield electrodes 27b gradually widens in width from one side to the other of the surrounding shield electrode 26b.

[0027] In this embodiment, the second shield electrode layer SL2 includes a plurality of second wirings WL2 and a plurality of second connection terminals CT2 formed by patterning a conductive layer. That is, a plurality of second wirings WL2 and a plurality of second connection terminals CT2 are provided on the second main surface S2. Multiple second wirings WL2 are arranged in the gap between the peripheral shield electrode 26b and the second shield electrode 27b, and in the gap between two adjacent second shield electrodes 27b in the first direction X. The number of second wirings WL2 corresponds to the number of second sensor electrodes, which will be described later. The plurality of second connection terminals CT2 are provided along one side edge of the second main surface S2 and are arranged at intervals in the first direction X.

[0028] Multiple second wirings WL2 each extend in the second direction Y and are arranged substantially parallel to one another. One end of each second wiring WL2 is located near the second shield electrode 27b, and the other end is connected to the second connection terminal CT2. Each of the multiple second wirings WL2 is electrically isolated from the second shield electrode 27b. The second insulating layer IL2 (see Figure 7) is laminated on the second main surface S2, superimposed on the second shield electrode layer SL2. The second insulating layer IL2 covers the surrounding shield electrode 26b, the second shield electrode 27b, and the second wiring WL2, except for the second connection terminal CT2. The second insulating layer IL2 can be made of a light-transmitting insulating material, such as a resin material such as polyimide, vinyl resin, or polycarbonate. Furthermore, in order to reduce coupling between the first wiring WL1 and the second wiring WL2 and the sensor electrodes PX1 and PX2, it is preferable that the line widths of the first wiring WL1 and the second wiring WL2 be thin, preferably set to 100 μm or less. Also, it is preferable that the first insulating layer IL1 and the second insulating layer IL2 be thick, for example, set to a layer thickness of about 200 μm.

[0029] As shown in Figures 2 and 6, a second sensor electrode layer SE2 and a second surface protection layer PL2 are laminated on top of the second shield electrode layer SL2. The second sensor electrode layer SE2 has a rectangular detection region SA and a peripheral region (non-detection region) BE located around the detection region SA. The second sensor electrode layer SE2 includes a plurality of second sensor electrodes PX2 and peripheral electrodes AX2 formed by patterning a conductive layer.

[0030] Multiple second sensor electrodes PX2 are provided in the detection region SA. The multiple second sensor electrodes PX2 are arranged in a matrix along the first direction X and the second direction Y. For example, the second sensor electrodes PX2 are arranged in a 9x11 matrix. Each second sensor electrode PX2 is, in one example, composed of a rectangular planar pattern. The peripheral electrode AX2 is provided in the peripheral region BE. The peripheral electrode AX2 extends along the four sides of the detection region SA and surrounds the second sensor electrodes PX2. The multiple second sensor electrodes PX2 are electrically independent of each other and are also electrically independent of the peripheral electrode AX2.

[0031] The second sensor electrode PX2 is formed of a translucent conductive material such as indium-tin mixed oxide (ITO) or indium-zinc mixed oxide (IZO). The second sensor electrode PX2 may also be formed of a metal such as titanium, molybdenum, or copper, or an alloy containing one or more of these metals. The surrounding electrode AX2 may be formed of the same material as the second sensor electrode PX2, or it may be formed of a different metal material than the second sensor electrode PX2.

[0032] The second surface protection layer PL2 is an insulating protective layer and is laminated over the second sensor electrode PX2 and the surrounding electrode AX2, covering the entire surface of the second insulating layer IL2. In one example, solder resist can be used as the second surface protection layer PL2. The second surface protection layer PL2 is not limited to this and may be formed from polymer materials such as quartz, polyimide, or polycarbonate.

[0033] Figure 7 is a cross-sectional view of the sensor substrate along line A-A in Figure 1. As shown in Figures 3, 4, and 7, in the first sensor layer 22A provided on the first main surface S1 of the base substrate 20, each row of first sensor electrodes PX1 faces the first shield electrode 27a and a plurality of first wirings WL1, with the first insulating layer IL1 in between. One end of each first wiring WL1 is electrically connected to the corresponding first sensor electrode PX1 via a plated through-hole MH1. Thus, each first sensor electrode PX1 is electrically connected to the first connection terminal CT1 via the plated through-hole MH1 and the first wiring WL1. The peripheral electrode AX1 of the first sensor electrode layer SE1 faces the peripheral shield electrode 26a of the first shield electrode layer SL1, with the first insulating layer IL1 in between. At least a portion of the peripheral electrode AX1 is electrically connected to the peripheral shield electrode 26a via a plated through-hole MH3.

[0034] As shown in Figures 5, 6, and 7, in the second sensor layer 22B provided on the second main surface S2 of the base substrate 20, each row of second sensor electrodes PX2 faces the second shield electrode 27b and the second wiring WL2, with the second insulating layer IL2 in between. One end of each second wiring WL2 is electrically connected to the corresponding second sensor electrode PX2 via a plated through-hole MH2. Thus, each second sensor electrode PX2 is electrically connected to the second connection terminal CT2 via the plated through-hole MH2 and the second wiring WL2. The peripheral electrode AX2 of the second sensor electrode layer SE2 faces the peripheral shield electrode 26b of the second shield electrode layer SL2, with the second insulating layer IL2 in between. At least a portion of the peripheral electrode AX2 is electrically connected to the peripheral shield electrode 26b via a plated through-hole MH4.

[0035] In this embodiment, the multiple second sensor electrodes PX2 are arranged facing each of the multiple first sensor electrodes PX1 in the third direction Z. Similarly, the multiple second shield electrodes 27b are arranged facing each of the multiple first shield electrodes 27a and are sandwiched between the first sensor electrodes PX1 and the second sensor electrodes PX2. When the sensor substrate 12 is viewed from the first main surface S1, the entire surface of each first sensor electrode PX1 overlaps the first shield electrode 27a and the second shield electrode 27b. Similarly, when the sensor substrate 12 is viewed from the second main surface S2, the entire surface of each second sensor electrode PX2 overlaps the second shield electrode 27b and the first shield electrode 27a.

[0036] Figure 8 is a cross-sectional view of the sensor substrate along line B-B in Figure 1. As shown in Figures 1 and 8, in one example, a first connector CN1 is mounted on the side edge of the first main surface S1 of the base substrate 20. The first connector CN1 includes the aforementioned plurality of first connection terminals CT1. A plurality of first wirings WL1 and a surrounding shield electrode 26a are connected to the first connection terminals CT1.

[0037] Multiple second connection terminals CT2 provided on the second main surface S2 of the base substrate 20 face multiple first connection terminals CT1 across the base substrate 20. In this embodiment, the multiple second connection terminals CT2 are electrically connected to the first connection terminals CT1 (first connector CN1) for example, via plated through-holes MH5 formed in the base substrate 20. As described above, multiple second wirings WL2 and surrounding shield electrodes 26b are connected to the multiple second connection terminals CT2.

[0038] The detection circuit board 14 has a second connector CN2 and a third connector CN3 mounted on a printed circuit board 15. The first connector CN1 of the sensor board 12 and the second connector CN2 of the detection circuit board 14 are electrically connected by an FPC 18. As a result, the first sensor layer 22A and the second sensor layer 22B of the sensor board 12 are electrically connected to the detection circuit board 14 via the first connector CN1, the FPC 18, and the second connector CN2. In addition, the external control device (host) 16 is electrically connected to the detection circuit board 14 via an FPC 17 and the third connector CN3.

[0039] As shown in Figure 8, in the operating state of the hover detection device 10, drive signals are supplied from the detection circuit board 14 via wiring to a plurality of first sensor electrodes PX1 of the first sensor layer 22A and a plurality of second sensor electrodes PX2 of the second sensor layer 22B. The drive signals may be pulse voltages. At a timing synchronized with the drive signals, a predetermined voltage, for example, the second reference potential GND2 described later, is applied from the detection circuit board 14 via wiring to the first shield electrode 27a and surrounding shield electrode 26a of the first sensor layer 22A and the second shield electrode 27b and surrounding shield electrode 26b of the second sensor layer 22B. The first shield electrode 27a and the second shield electrode 27b function as active shields whose potential fluctuates periodically in response to changes in the reference potential.

[0040] As a result, a pseudo-capacitance is formed between the first sensor electrode PX1 and the first shield electrode 27a, and a current equivalent to the self-capacitance CP1 (sometimes referred to as the baseline current) flows through the first sensor electrode PX1. Similarly, a pseudo-capacitance is formed between the second sensor electrode PX2 and the second shield electrode 27b, and a current equivalent to the self-capacitance CP1 (sometimes referred to as the baseline current) flows through the second sensor electrode PX2.

[0041] When an object to be detected, such as a finger, approaches the first sensor layer 22A from the side of the first main surface S1 of the sensor substrate 12, a capacitance CP2 is formed between the first sensor electrode PX1 and the finger. In this case, currents corresponding to the capacitances CP1 and CP2 flow through the first sensor electrode PX1. Therefore, a first detection signal corresponding to the capacitances CP1 and CP2 is output from the first sensor electrode PX1.

[0042] When an object to be detected, such as a finger, approaches the second sensor layer 22B from the side of the second main surface S2 of the sensor substrate 12, a capacitance CP2 is formed between the second sensor electrode PX2 and the finger. In this case, currents corresponding to the capacitances CP1 and CP2 flow through the second sensor electrode PX2. Therefore, a second detection signal corresponding to the capacitances CP1 and CP2 is output from the second sensor electrode PX2. Note that the object to be detected is not limited to a finger and may be an object including a conductor, such as a stylus pen.

[0043] FIG. 9 is a block diagram showing an example of the schematic configuration of the hover detection device. As shown in FIG. 9, a detection circuit board 14 that functions as a controller includes an AFE circuit 24 that performs hover detection based on a detection signal from the sensor substrate 12, a control circuit (MCU) 25 that controls the hover detection operation in the AFE circuit 24, a reference potential generation circuit 26, and a power supply PW1 that supplies a drive voltage. The AFE circuit 24 includes a first AFE circuit (sometimes referred to as a first detection circuit) 24A that performs hover detection based on a detection signal from the first sensor layer 22A, and a second AFE circuit (sometimes referred to as a second detection circuit) 24B that performs hover detection based on a detection signal from the second sensor layer 22B.

[0044] The MCU (Micro Control Unit) 25 and the reference potential generation circuit 26 operate with a first reference potential GND1, which is a fixed potential, as the ground potential. The first AFE circuit 24A, the second AFE circuit 24B, and the sensor substrate 12 operate with a second reference potential GND2, which is a periodically varying potential generated by the reference potential generation circuit 26, as the ground potential.

[0045] The first AFE circuit 24A is a signal conditioning circuit. In one example, it includes a readout circuit 51, an analog-to-digital converter (ADC) 52, a digital signal processor (DSP) circuit 53, and a memory 54. The first AFE circuit 24A is connected to the first sensor electrodes PX1 and the first shield electrode 27a of the first sensor layer 22A.

[0046] Under the control of the MCU 25, the first AFE circuit 24A generates a drive signal (reference signal or baseline current) AS1 and outputs it to a plurality of first sensor electrodes PX1 via the first wiring WL1. The first AFE circuit 24A outputs the second reference potential GND2 to the first shield electrode 27a and the surrounding shield electrode 26a at the same timing as the timing of supplying the drive signal to the first sensor electrodes PX1.

[0047] The first AFE circuit 24A reads a detection signal Rx1 from the first sensor electrodes PX1 according to the drive signal, performs signal conditioning (amplification, ADC conversion, filtering), and then outputs it to the MCU 25. That is, the readout circuit 51 of the first AFE circuit 24A acquires the detection signal Rx from each of the first sensor electrodes PX1. The ADC circuit 52 converts the acquired detection signal Rx1 from an analog signal to a digital signal. The DSP circuit 53 performs digital filtering on the digital data converted by the ADC circuit 52 into a digital signal and generates sensing data based on the detection signal Rx1. The first AFE circuit 24A outputs the generated sensing data (rectangular wave signal Tx) to the MCU 25.

[0048] The signals between the first AFE circuit 24A and the MCU 25 are transmitted, in one example, by a serial peripheral interface (SPI), which is a clock synchronous serial interface. It may be configured to communicate data in other ways, not limited to SPI.

[0049] The second AFE circuit 24B is configured similarly to the first AFE circuit 24A. That is, the second AFE circuit 24B is a signal adjustment circuit and, in one example, includes a read circuit 51, an ADC circuit 52, a DSP circuit 53, and a memory 54. The second AFE circuit 24B is connected to the second sensor electrode PX2 and the second shield electrode 27b of the second sensor layer 22B.

[0050] The second AFE circuit 24B generates a drive signal (reference signal or baseline current) AS2 under the control of the MCU 25 and outputs it to multiple second sensor electrodes PX2 via the second wiring WL2. At the same timing as supplying the drive signal to the second sensor electrodes PX2, the second AFE circuit 24B also outputs a second reference potential GND2 to the second shield electrode 27b and the surrounding shield electrode 26b.

[0051] The second AFE circuit 24B reads the detection signal Rx2 from the second sensor electrode PX2 in response to the drive signal, adjusts the signal (amplification, AD conversion, filtering), and then outputs it to the MCU 25. In other words, the readout circuit 51 of the second AFE circuit 24B acquires the detection signal Rx2 from each of the second sensor electrodes PX2. The ADC circuit 52 converts the acquired detection signal Rx2 from an analog signal to a digital signal. The DSP circuit 53 performs digital filtering on the digital data converted by the ADC circuit 52 and generates sensing data based on the detection signal Rx2. The second AFE circuit 24B outputs the generated sensing data (square wave signal Tx) to the MCU 25 via SPI.

[0052] The MCU25 includes a readout circuit 61, a noise detection circuit 62, a coordinate calculation circuit 63, a communication interface I / F, a memory 64, and the like. Each circuit element operates with a fixed potential, the first reference potential GND1, as the ground potential.

[0053] The readout circuit 61 acquires sensing data Tx output from the first AFE circuit 24A and the second AFE circuit 24B. The noise determination circuit 62 performs noise determination processing based on the sensing data acquired by the readout circuit 61. The coordinate calculation circuit 63 performs coordinate calculation processing based on the sensing data acquired by the readout circuit 61. The coordinate calculation circuit 63 determines whether or not the object to be detected is approaching the first sensor layer 22A, and whether or not the object to be detected is approaching the second sensor layer 22B. The coordinate calculation circuit 63 may also be a logic circuit that determines the coordinate position of the object to be detected.

[0054] In detail, the coordinate calculation circuit 63 determines whether or not the object to be detected is approaching the first sensor layer 22A based on the digitized detection signal Tx. When the first sensor electrode PX1 outputs a detection signal indicating a change in capacitance, the coordinate calculation circuit 63 determines whether or not the detected capacitance has changed from the previously detected capacitance. If the result of the determination shows that the detected capacitance has changed by a predetermined amount or more from the previously detected capacitance, the coordinate calculation circuit 63 determines that the object to be detected is approaching the first sensor electrode PX1 whose capacitance is changing, and determines the position of the object to be detected on the x and y coordinates based on the position of the first sensor electrode PX1 that output the detection signal RX1. The coordinate calculation circuit 63 generates coordinate information indicating the determined position of the object to be detected on the x and y coordinates. The coordinate information includes x coordinate information (first coordinate information) and y coordinate information (second coordinate information). The coordinate calculation circuit 63 transmits the coordinate information to the host 16 via the I / F.

[0055] Furthermore, if the detected capacitance is the same as the previously detected capacitance, or if the capacitance has changed but the amount of change is less than a predetermined amount, it is determined that there is no approach of the object to be detected to the first sensor electrode PX1 having that capacitance.

[0056] Furthermore, the coordinate calculation circuit 63 determines whether or not the object to be detected is approaching the second sensor layer 22B based on the digitized detection signal Tx. When the second sensor electrode PX2 outputs a detection signal indicating a change in capacitance, the coordinate calculation circuit 63 determines whether or not the detected capacitance has changed from the previously detected capacitance. If the result of the determination shows that the detected capacitance has changed by more than a predetermined amount from the previously detected capacitance, the coordinate calculation circuit 63 determines that the object to be detected is approaching the second sensor electrode where the capacitance is changing, and determines the position of the object to be detected on the xy coordinate system based on the position of the second sensor electrode PX2 that output the detection signal. The coordinate calculation circuit 63 generates coordinate information indicating the determined position of the object to be detected on the xy coordinate system. The coordinate calculation circuit transmits the coordinate information to the host 16 via the I / F.

[0057] If the detected capacitance is the same as the previously detected capacitance, or if the capacitance has changed but the amount of change is less than a predetermined amount, it is determined that there is no approach of the object to be detected to the second sensor electrode PX2 having that capacitance.

[0058] In this disclosure, the MCU 25 has a function to change the driving frequency in the capacitive hover detection, that is, the fundamental frequency of the detection signal (square wave signal) Tx output from the first AFE circuit 24A and the second AFE circuit 24B. By changing the fundamental frequency, the influence of noise can be suppressed. Hereinafter, the change of the fundamental frequency of the square wave signal Tx may be referred to as "frequency hopping".

[0059] Figure 10 is a flowchart illustrating an example of hover detection operation in the hover detection device 10. When power is supplied from the power supply PW1 and the sensing operation by the hover detection device 10 begins (ST1), the hover detection device 10 performs a baseline scan to acquire detection signals Rx1 and Rx2 when the object to be detected is not in close proximity to the sensor substrate 12 (ST2). After the baseline scan, the MCU 25 performs normal hover detection operation (sensing) (ST3), that is, it outputs drive signals to the first sensor electrode PX1 and the first shield electrode 27a, and simultaneously outputs drive signals to the second sensor electrode PX2 and the second shield electrode 27b. Based on the difference between the detection signal Rx acquired by the baseline scan (ST2) and the detection signal Rx acquired by sensing (ST3), the MCU 25 performs the noise determination process and coordinate calculation process described above. More specifically, the noise determination circuit 62 performs noise determination processing based on the difference between the detection signal Rx acquired by the baseline scan and the detection signal Rx acquired by sensing (ST4). Furthermore, the coordinate calculation circuit 63 performs coordinate calculation processing based on the difference between the detection signal Rx acquired by baseline scanning and the detection signal Rx acquired by sensing (ST5).

[0060] In Figure 10, an example is shown in which the coordinate calculation process (ST5) is performed after the noise detection process (ST4). However, the noise detection process may be performed after the coordinate calculation process, or the noise detection process and the coordinate calculation process may be performed in parallel.

[0061] Next, the MCU 25 determines whether the above-described conditions for frequency hopping (hereinafter also simply referred to as "frequency hopping conditions") have been met (step S6). Specifically, the MCU 25 determines whether a signal including a frequency hopping command instructing the hover detection device 10 to perform frequency hopping has been input from the external control device (host) 16 connected via the FPC 17. Note that the frequency hopping conditions are not limited to those described above. For example, the MCU 25 may determine whether the frequency hopping conditions have been met.

[0062] If the frequency hopping condition is met in ST6, the MCU25 sets the drive frequency for hover detection, i.e., the fundamental frequency of the square wave signal Tx output from the AFE circuit24, to the frequency after frequency hopping (ST7).

[0063] If the frequency hopping condition is not met in ST6, and after frequency hopping is performed in ST7, the MCU 25 determines whether the sensing operation has finished (ST8). If it has finished, the hover detection operation is terminated. Examples of when the sensing operation is terminated include when power is no longer supplied from the power supply PW1, or when a command to terminate the sensing operation is input to the hover detection device 10 from the host 16. If the sensing operation of the hover detection device 10 has not finished, the MCU 25 repeatedly executes the operations from ST3 onward.

[0064] Figure 12 is a timing chart showing an example of the operation of a hover detection device 10 capable of frequency hopping. The detection operation in the hover detection device 10 is defined by a processing flow in units of repetition period Cy. First, a clock signal (V-Sync) indicating the start of the repetition period Cy is output at a predetermined period. In one example, this clock signal is output at timings T1 and T2. The following describes the flow of operation within the repetition period Cy, starting from timing T1.

[0065] Starting from timing T1, the sensing operation corresponding to ST3 described above is performed. The sensing operation is performed during period Pe1, from timing T1 until the start of period Pe2, when an interrupt signal (IRQ) indicating the end of the sensing operation is generated.

[0066] Between the end of period Pe2 and timing T2, periods Pe3, Pe4, Pe5, and Pe6 occur sequentially. Period Pe3 is the period during which sensing data output from the AFE circuit 24 is read (AFE Read). Period Pe4 is the period during which the noise determination process corresponding to ST4 and the coordinate calculation process corresponding to ST5 are executed in parallel. Period Pe5 is the period during which, if frequency hopping is performed, a command output (writing of information) is made to the AFE circuit 24 to set the fundamental frequency of the square wave signal Tx to the frequency after frequency hopping. Period Pe6 is a blank period from the end of period Pe5 to timing T2.

[0067] Starting from timing T2, the operations of periods Pe1, Pe2, Pe3, Pe4, Pe5, and Pe6 described above are repeated again. Thereafter, each time a clock signal (V-Sync) indicating the start of the repeating period Cy is output at a predetermined interval, periods Pe1 to Pe6 described above are repeated.

[0068] The hover detection device 10 according to this embodiment, configured as described above, includes a first sensor layer 22A and a second sensor layer 22B provided on both sides S1 and S2 of the base substrate 20, and a detection circuit board 14 that performs hover detection based on detection signals from the first sensor layer 22A and the second sensor layer 22B. That is, the hover detection device 10 can detect the approach or contact of an object to be detected on the first main surface S1 side using the first sensor layer 22A, and can detect the approach or contact of an object to be detected on the second main surface S2 side using the second sensor layer 22B. As a result, even if the sensor substrate 12 of the hover detection device 10 is embedded in a wall or the like, it is possible to operate and detect hover from both sides of the sensor substrate 12. In other words, according to this embodiment, it is possible to provide a detection device that can be operated and detected from both sides.

[0069] Furthermore, according to the first embodiment, the first wiring WL1 and the second wiring WL2 are provided on shield electrode layers SL1 and SL2, which are separate layers from the sensor electrode layers SE1 and SE2 on which the sensor electrodes PX1 and PX2 are provided. With this configuration, compared to a configuration in which the first wiring WL1 and the second wiring WL2 are provided on the same layer as the sensor electrode PX, the possibility of false detection of the object to be detected by the first and second wiring is reduced, and the coordinate detection accuracy in hover detection can be improved. In addition, in the sensor electrode layers SE1 and SE2, the absence of wiring allows for a larger dimension of the sensor electrode PX.

[0070] According to the first embodiment, the shield electrodes 27a and 27b are each formed in a comb-like shape. By devising the shape and arrangement of each shield electrode, when the sensor substrate 12 is viewed from the first main surface S1, the entire surface of each first sensor electrode PX1 overlaps with the first shield electrode 27a and the second shield electrode 27b. Similarly, when the sensor substrate 12 is viewed from the second main surface S2, the entire surface of each second sensor electrode PX2 overlaps with the second shield electrode 27b and the first shield electrode 27a. Therefore, the first and second shield electrodes 27a and 27b can be effectively used as active shields to perform hover detection.

[0071] Next, a hover detection device according to other embodiments or modifications will be described. In the other embodiments or modifications described below, parts identical to those in the first embodiment described above will be denoted by the same reference numerals as in the first embodiment, and their detailed descriptions may be simplified or omitted.

[0072] (Second Embodiment) Figure 13 is a block diagram showing an example of a schematic configuration of a hover detection device according to the second embodiment. In the hover detection device 10 according to the first embodiment described above, a double-sided detection device with a simultaneous drive method is illustrated, in which the first sensor layer 22A on the first main surface S1 side and the second sensor layer 22B on the second main surface S2 side are driven simultaneously. In contrast, the hover detection device according to the second embodiment is configured as a double-sided detection device with an alternating drive method, in which the first sensor layer 22A and the second sensor layer 22B are driven alternately.

[0073] As shown in Figure 13, according to the hover detection device 10 of the second embodiment, since there is limited channel capacity in the AFE circuit, a first AFE circuit 24A for the first sensor layer 22A and a second AFE circuit 24B for the second sensor layer 22B are provided independently, and an alternating drive configuration is used in which these first AFE circuits 24A and second AFE circuits 24B are switched and used alternately by an analog switch (SW) 66. The analog switch 66 is connected between the first AFE circuit 24A and the second AFE circuit 24B, and between the MCU 25 and the first sensor layer 22A and the second sensor layer 22B, and under the control of the MCU 25, the first AFE circuit 24A and the second AFE circuit 24B are alternately connected to the sensor board 12.

[0074] The first AFE circuit 24A generates a drive signal (reference signal or baseline current) AS1 under the control of the MCU 25 and outputs the drive signal AS1 to a plurality of first sensor electrodes PX1 via the analog switch 66. At the same timing as supplying the drive signal to the first sensor electrodes PX1, the first AFE circuit 24A outputs a second reference potential GND2 to the first shield electrode 27a and the surrounding shield electrode 26a. Furthermore, in response to the drive signal, the first AFE circuit 24A reads a detection signal Rx1 from each of the first sensor electrodes PX1, generates sensing data Tx based on the detection signal Rx1, and outputs it to the MCU 25.

[0075] The second AFE circuit 24B generates a drive signal (reference signal or baseline current) AS2 under the control of the MCU 25 and outputs the drive signal AS2 to multiple second sensor electrodes PX2 via the analog switch 66. At the same timing as supplying the drive signal to the second sensor electrodes PX2, the second AFE circuit 24B outputs a second reference potential GND2 to the second shield electrode 27b and the surrounding shield electrode 26b. Furthermore, in response to the drive signal, the second AFE circuit 24B reads a detection signal Rx2 from each of the second sensor electrodes PX2, generates sensing data Tx based on the detection signal Rx2, and outputs it to the MCU 25.

[0076] The analog switch 66 is switched under the control of the MCU 25 between a first selected position that connects the first AFE circuit 24A and the sensor board 12, and a second selected position that connects the second AFE circuit 24B and the sensor board 12. In the second embodiment, the other components of the hover detection device 10 are the same as those of the hover detection device according to the first embodiment.

[0077] Figure 11 is a flowchart showing a part of the hover detection operation in the hover detection device according to the second embodiment. The hover detection device 10 according to the second embodiment performs the sensing operations (ST1 to ST8) shown in Figure 10, but replaces only the sensing (ST3) with the sensing (ST3) shown in Figure 11. That is, in sensing ST3, the hover detection device 10 sequentially performs switching of the analog switch 66 (ST3A), sensing by the first AFE circuit 24A (ST3B), switching of the analog switch 66 (ST3C), and sensing by the second AFE circuit 24B (ST3D).

[0078] First, the MCU 25 switches the analog switch 66 to the first selected position (ST3a). Next, during sensing (ST3b), the first AFE circuit 24A outputs a drive signal AS1 to the first sensor electrode PX1 and the first shield electrode 27a in response to the drive signal from the MCU 25. Furthermore, it reads a detection signal Rx1 from each of the first sensor electrodes PX1, generates sensing data Tx, and outputs it to the MCU 25. Next, the MCU 25 switches the analog switch 66 to the second selected position (ST3c).

[0079] The second AFE circuit 24B outputs a drive signal AS2 to the second sensor electrode PX2 and the second shield electrode 27b in response to a drive signal from the MCU 25. Furthermore, it reads a detection signal Rx2 from each of the second sensor electrodes PX2, generates sensing data Tx, and outputs it to the MCU 25 (ST3d). Subsequently, the MCU 25 sequentially executes ST4 to ST8 shown in Figure 10.

[0080] Figure 14 is a timing chart showing an example of the operation of the hover detection device 10 according to the second embodiment. The detection operation in the hover detection device 10 is defined in terms of processing flow in units of repetition period Cy. First, clock signals (V-Sync1 and V-Sync2) indicating the start of the repetition period Cy are output at predetermined intervals. In one example, the clock signal (V-Sync1) is output at timings T1 and T2, and the clock signal (V-Sync2) is output in the middle of timings T1 and T2. The following describes the flow of operation within the repetition period Cy, starting from timing T1.

[0081] Starting from timing T1, the analog switch 66 corresponding to ST3a and ST3b described above is switched, and the first sensor layer 22A and the first AFE circuit 24A perform a sensing operation (Sensing 1). The sensing operation is performed from timing T1 until the start of period Pe1, when an interrupt signal (IRQ1) indicating the end of the sensing operation is generated.

[0082] Starting from the clock signal (V-Sync2) output at the end of period Pe2, the switching operation of the analog switch 66 corresponding to ST3c and ST3d described above, and the sensing operation (Sensing2) by the second sensor layer 22B and the second AFE circuit 24B are performed. The sensing operation is performed during period Pe3 until the start of period Pe4, when an interrupt signal (IRQ2) indicating the end of the sensing operation is generated.

[0083] Between the end of period Pe4 and timing T2, periods Pe5, Pe6, Pe7, and Pe8 occur sequentially. Period Pe5 is the period during which sensing data output from the first AFE circuit 24A and the second AFE circuit 24B is read (AFE Read). Period Pe6 is the period during which the noise determination process corresponding to ST4 and the coordinate calculation process corresponding to ST5 are executed in parallel. Period Pe7 is the period during which, if frequency hopping is performed, commands are output (information is written) to the first AFE circuit 24A and the second AFE circuit 24B to set the fundamental frequency of the square wave signal Tx to the frequency after frequency hopping. Period Pe8 is a blank period from the end of period Pe7 to timing T2.

[0084] Starting from timing T2, the operations of the above-described periods Pe1, Pe2, Pe3, Pe4, Pe5, Pe6, Pe7, and Pe8 are repeated again. Thereafter, each time a clock signal (V-Sync1 and V-Sync2) indicating the start of the repeating period Cy is output at a predetermined interval, the above-described periods Pe1 to Pe8 are repeated.

[0085] According to the alternating drive type hover detection device 10 of the second embodiment configured as described above, the first sensor layer 22A and the first AFE circuit 24A can detect the approach or contact of the object to be detected on the first main surface S1 side, and the second sensor layer 22B and the second AFE circuit 24B can detect the approach or contact of the object to be detected on the second main surface S2 side. As a result, even if the sensor substrate 12 of the hover detection device 10 is embedded in a wall or the like, it is possible to operate and detect hover from both sides of the sensor substrate 12. In other words, according to this embodiment, it is possible to provide a detection device that can be operated and detected from both sides.

[0086] (First Modified Example) Figure 15 is a schematic plan view showing the first sensor layer and the second sensor layer of the hover detection device according to the first modified example. In the first sensor layer 22A and the second sensor layer 22B, the size of the detection area SA, the number of sensor electrodes, and the electrode size are not limited to being the same, but may be different from each other. As shown in Figure 15(a), according to the first modified example, for example, the number of first sensor electrodes PX1 in the first sensor layer 22A is 5 × 5 = 25, and each rectangular first sensor electrode PX1 is arranged in a matrix.

[0087] As shown in Figure 15(b), the size of the detection area SA in the second sensor layer 22B is smaller than the detection area SA of the first sensor layer 22A, for example, set to about 1 / 4. The number of second sensor electrodes PX2 in the second sensor layer 22B is, for example, 3 × 4 = 12, and each rectangular second sensor electrode PX2 is arranged in a matrix. The electrode size of the second sensor electrode PX2 is set to be smaller than the electrode size of the first sensor electrode PX1. In the above first modified example, a detection device that can be operated and detected from both sides can be provided.

[0088] (Second Modification) Figure 16 is a cross-sectional view of the hover detection device according to the second modification, and Figure 17 is a plan view of the hover detection device according to the second modification. The connector connecting the sensor board 12 and the detection circuit board 14 is not limited to one, but may be used in multiple ways. If there are many sensor electrodes, the connectors may be separated.

[0089] As shown in Figures 16 and 17, according to the second modification, a first connector CN1 is mounted on the side edge of the first main surface S1 of the base substrate 20. The first connector CN1 is connected to a plurality of first wirings WL1 and a surrounding shield electrode. A fourth connector CN4 is mounted on the side edge of the second main surface S2 of the base substrate 20. The fourth connector CN4 is connected to a plurality of second wirings WL2 and a surrounding shield electrode. Through-holes MH5 are not required.

[0090] The detection circuit board 14 includes a second connector CN2 and a third connector CN3 mounted on the upper surface of the printed circuit board 15, and a fifth connector CN5 mounted on the lower surface of the printed circuit board 15. The first connector CN1 of the sensor board 12 and the second connector CN2 of the detection circuit board 14 are electrically connected by an FPC 18. The fourth connector CN4 of the sensor board 12 and the fifth connector CN5 of the detection circuit board 14 are electrically connected by an FPC 19.

[0091] As a result, the first sensor layer 22A of the sensor substrate 12 is electrically connected to the detection circuit board 14 via the first connector CN1, FPC 18, and second connector CN2. The second sensor layer 22B of the sensor substrate 12 is electrically connected to the detection circuit board 14 via the fourth connector CN4, FPC 19, and fifth connector CN5. The control device (host) 16 is also electrically connected to the detection circuit board 14 via the FPC 17 and third connector CN3. In this second modified example, a detection device that can be operated and detected from both sides can be provided.

[0092] (Third Modification) Figure 18 is a cross-sectional view of a hover detection device according to the third modification. The sensor substrate 12 and the detection circuit board 14 are not limited to being separate components, but may be formed integrally. As shown in Figure 18, according to the third modification, the sensor substrate 12 and the detection circuit board 14 are formed integrally. That is, the printed circuit board of the detection circuit board 14 is composed of the base substrate 20 and wiring WL1 and WL2 of the sensor substrate 12. The semiconductor elements SD1 and SD2 (for example, AFE circuit 24, MCU 25) and the third connector CN3 of the detection circuit board 14 are mounted on the first main surface S1 side of the base substrate 20 and connected to the first wiring WL1. The control device (host) 16 is electrically connected to the detection circuit board 14 via the FPC 17 and the third connector CN3. The semiconductor elements SD1 and SD2 (for example, AFE circuit 24 and MCU 25) and the third connector CN3 may be mounted on the second main surface S2 side of the base substrate 20 and connected to the second wiring WL2.

[0093] In the third modified example described above, a detection device that can be operated and detected from both sides can be provided. Furthermore, by integrally forming the base substrate 20 and the detection circuit board 14, it is possible to reduce the number of components and miniaturize the device.

[0094] (Fourth Modification) Figure 19 is (a) a side view of the hover detection device according to the fourth modification, and (b) a cross-sectional view of the sensor substrate. The sensor substrate 12 of the hover detection device 10 may be made of a light-transmitting material. As shown in Figures 19(a) and (b), according to the fourth modification, the sensor substrate 12 has a shield electrode layer SL that functions as a base substrate, a first sensor layer 22A attached to the first main surface S1 of the shield electrode layer SL by an adhesive layer Ad1, and a second sensor layer 22B attached to the second main surface S2 of the shield electrode layer SL by an adhesive layer Ad2.

[0095] The shield electrode layer SL is formed of a transparent conductive film and constitutes a solid rectangular shield electrode 27. The adhesive layers Ad1 and Ad2 each use transparent adhesive sheets for optical applications. The first sensor layer 22A is composed of a first sensor electrode layer SE1 formed of a transparent conductive film and a transparent surface protection layer (protective film) PL1. In this modified example, the first sensor electrode layer SE1 includes a plurality of first sensor electrodes PX1 and a plurality of first wirings WL1. The side of the first sensor electrode layer SE1 of the first sensor layer 22A is attached to the adhesive layer Ad1.

[0096] The second sensor layer 22B is composed of a second sensor electrode layer SE2 made of a transparent conductive film and a transparent surface protection layer (protective film) PL2. In this modified example, the second sensor electrode layer SE2 includes a plurality of second sensor electrodes PX2 and a plurality of second wirings WL2. The second sensor layer 22B is attached to the adhesive layer Ad2 on the side of the second sensor electrode layer SE2. The transparent conductive film described above can be formed from a light-transmitting conductive material such as indium-tin mixed oxide (ITO) or indium-zinc mixed oxide (IZO). The first sensor electrode layer SE1, the second sensor electrode layer SE2, and the shield electrode layer SL are electrically connected to the detection circuit board 14 via an FPC 18 and a connector CN2, respectively.

[0097] In the fourth modified example described above, a detection device that can be operated and detected from both sides can be provided. Furthermore, by placing the shield electrode 27 between the first sensor layer 22A and the second sensor layer 22B and making it shared on both sides, the number of layers in the sensor substrate 12 can be reduced, making it possible to construct a flexible sensor substrate. Moreover, by using a light-transmitting material, the sensor substrate 12 can be made almost transparent, which increases the degree of freedom in installing the detection device.

[0098] (Fifth Modification) Figure 20 is (a) a side view of the hover detection device according to the fifth modification and (b) a cross-sectional view of the sensor substrate. Figure 21 is a plan view showing (a) the first sensor electrode layer and (b) the shield electrode layer of the hover detection device according to the fifth modification. The sensor substrate 12 of the hover detection device 10 is not limited to a rigid circuit board, but may be made of a flexible printed circuit board (FPC) having a plurality of conductive layers. As shown in Figures 20(a) and (b), according to the fifth modification, the sensor substrate 12 is made of an FPC having three conductive layers, for example. In detail, the sensor substrate 12 has a first sensor layer 22A provided on the first main surface side, a second sensor layer 22B provided on the second main surface side, and a shield electrode layer SL and an adhesive layer (bonding sheet) Ad provided between the first sensor layer 22A and the second sensor layer 22B.

[0099] The first sensor layer 22A includes a first insulating layer IL1 made of polyimide or the like, a first sensor electrode layer (first conductive layer) SE1 laminated on one surface of the first insulating layer IL1, and a first surface protection layer PL1 laminated on the first sensor electrode layer SE1. As shown in Figure 21(a), the first sensor electrode layer SE1 includes a plurality of first sensor electrodes PX1 and a plurality of first wirings WL1 formed by patterning the conductive layer. Polyimide, solder resist, or the like is used as the first surface protection layer PL1.

[0100] As shown in Figures 20(b) and 21(b), a second conductive layer is laminated on the other side (opposite side) of the first insulating layer IL1. The second conductive layer is a shield electrode layer SL, which constitutes a solid rectangular shield electrode 27.

[0101] As shown in Figures 20(a) and (b), the second sensor layer 22B includes a second insulating layer IL2 made of polyimide or the like, a second sensor electrode layer (third conductive layer) SE2 laminated on one surface of the second insulating layer IL2, and a second surface protection layer PL2 laminated on the second sensor electrode layer SE2. The second sensor electrode layer SE2 includes a plurality of second sensor electrodes PX2 and a plurality of second wirings WL2 formed by patterning the conductive layer. Polyimide, solder resist, or the like is used as the second surface protection layer PL2.

[0102] The first sensor layer 22A and the second sensor layer 22B are laminated with a shield electrode layer SL and an adhesive layer Ad sandwiched between them. Specifically, the shield electrode layer SL is attached to the second insulating layer IL2 of the second sensor layer 22B by the adhesive layer Ad.

[0103] One end of the sensor substrate 12 may be directly connected to the connector CN2 of the detection circuit board 14. The first sensor electrode layer SE1, the shield electrode 27, and the second sensor electrode layer SE2 are electrically connected to the detection circuit board 14 via the connector CN2.

[0104] In the fifth modified example described above, a detection device that can be operated and detected from both sides can be provided. Furthermore, by placing the shield electrode 27 between the first sensor layer 22A and the second sensor layer 22B and using it for both sides, and by constructing the sensor substrate 12 using an FPC, it becomes possible to construct a flexible sensor substrate. This increases the degree of freedom in installing the detection device and expands its range of use.

[0105] (Sixth Modification) Figure 22 is a cross-sectional view of the sensor substrate of the hover detection device according to the sixth modification. As shown in Figure 22, according to the sixth modification, the sensor substrate 12 is made of an FPC having four conductive layers. More specifically, the sensor substrate 12 comprises a base insulating layer (base substrate) 20 made of polyimide or the like, a first sensor layer 22A provided on the side of the first main surface S1 of the base insulating layer 20, and a second sensor layer 22B provided on the side of the second main surface S2 of the base insulating layer 20.

[0106] The first sensor layer 22A has a first conductive layer laminated on the first main surface S1 of the base insulating layer 20. The first conductive layer forms a first shield electrode layer SL1. The first shield electrode layer SL1 includes a plurality of shield electrodes 27a and a plurality of first wiring WL1 formed by patterning the first conductive layer. The first sensor layer 22A further includes a first insulating layer IL1 made of polyimide or the like, a first sensor electrode layer (second conductive layer) SE1 laminated on one surface of the first insulating layer IL, and a first surface protection layer PL1 laminated on the first sensor electrode layer SE1. The first sensor electrode layer SE1 includes a plurality of first sensor electrodes PX1 formed by patterning the conductive layer. Polyimide, solder resist, or the like is used as the first surface protection layer PL1. The first insulating layer IL1 is laminated and attached to the first shield electrode layer SL1 via a first adhesive layer (bonding sheet) Ad1. Multiple first sensor electrodes PX1 are electrically connected to the first wiring WL1 via plated through-holes (not shown).

[0107] The second sensor layer 22B has a third conductive layer laminated on the second main surface S2 of the base insulating layer 20. The third conductive layer forms the second shield electrode layer SL2. The second shield electrode layer SL2 includes a plurality of shield electrodes 27b and a plurality of second wiring WL2 formed by patterning the third conductive layer. The second sensor layer 22B further includes a second insulating layer IL2 made of polyimide or the like, a second sensor electrode layer (fourth conductive layer) SE2 laminated on one surface of the second insulating layer IL2, and a second surface protection layer PL2 laminated on the second sensor electrode layer SE2. The second sensor electrode layer SE2 includes a plurality of second sensor electrodes PX2 formed by patterning the conductive layer. Polyimide, solder resist, or the like is used as the second surface protection layer PL2. The second insulating layer IL2 is laminated and attached to the second shield electrode layer SL2 via a second adhesive layer (bonding sheet) Ad2. Multiple second sensor electrodes PX2 are electrically connected to the second wiring WL2 via plated through-holes (not shown).

[0108] In the sixth modified example described above, a detection device that can be operated and detected from both sides can be provided. Furthermore, by constructing the sensor substrate 12 using an FPC, it becomes possible to construct a flexible sensor substrate. This increases the degree of freedom in installing the detection device and expands its range of applications.

[0109] (Third Embodiment) Next, a hover detection device according to the third embodiment will be described. Figure 23 is a plan view showing the schematic configuration of the hover detection device according to the third embodiment, and Figure 24 is a cross-sectional view of the hover detection device according to the third embodiment. Figure 25 is a plan view schematically showing (a) the first sensor layer and (b) the second sensor layer of the hover detection device according to the third embodiment.

[0110] In the hover detection device 10 according to the third embodiment, an independent shield electrode layer is omitted, and the first sensor electrode and the second sensor electrode are driven alternately so that when hover detection is performed with one sensor electrode, the other sensor electrode functions as a shield electrode.

[0111] As shown in Figures 23 and 24, the hover detection device 10 according to this embodiment includes a sensor substrate 12 and a detection circuit board 14 that drives the sensor substrate 12 and processes detection signals. The detection circuit board 14 is connected to an external control device (host computer) 16. The sensor substrate 12 has a base substrate 20 as a core material, a first sensor layer 22A laminated on the first main surface S1 side of the base substrate 20, and a second sensor layer 22B laminated on the second main surface S2 side of the base substrate 20. In this embodiment, the base substrate 20 is a rigid substrate such as a glass substrate or a glass epoxy substrate. The first sensor layer 22A is a capacitive sensor array that detects the approach or contact of an object to be detected to the first main surface S1 side. The second sensor layer 22B is a capacitive sensor array that detects the approach or contact of an object to be detected to the second main surface S2 side.

[0112] As shown in Figures 24 and 25(a), the first sensor layer 22A includes a first sensor electrode layer SE1 made of a conductive layer laminated on the first main surface S1 of the base substrate 20, and a first surface protection layer PL1 laminated on the first sensor electrode layer SE1. The first sensor electrode layer SE1 has a plurality of first sensor electrodes PX1 and a plurality of first wirings WL1 formed by patterning the conductive layer. The first sensor layer 22A has, for example, a rectangular detection region SA and a peripheral region (non-detection region) BE located around the detection region SA.

[0113] Multiple first sensor electrodes PX1 are provided in the detection region SA. The multiple first sensor electrodes PX1 are arranged in a matrix along the first direction X and the second direction Y. For example, if the first direction X is the row and the second direction is the column, the first sensor electrodes are arranged in a 5x5 matrix. Each first sensor electrode PX1 is, in one example, composed of a rectangular planar pattern. The first sensor electrodes PX1 are made of metals such as titanium, molybdenum, and copper, or alloys containing one or more of these metals. The first sensor electrodes PX1 may also be made of a translucent conductive material such as indium-tin mixed oxide (ITO) or indium-zinc mixed oxide (IZO).

[0114] The base substrate 20 integrally has a protrusion 20c projecting in a second direction Y from one side edge. On the first main surface S1, a connection terminal (not shown) and a first connector CN1 are provided on the protrusion 20c. Multiple first wirings WL1 are provided in the gaps between the non-detection region BE and the rows of first sensor electrodes PX1; in this case, five wirings are provided in each. One end of each first wiring WL1 is connected to the corresponding first sensor electrode PX1, and the other end extends through the peripheral region BE to the protrusion 20c and is connected to the first connector CN1.

[0115] The first surface protection layer PL1 is an insulating protective layer and is laminated on the first main surface S1 of the base substrate 20, superimposed on the first sensor electrode PX1 and the first wiring WL1. In one example, solder resist can be used as the first surface protection layer PL1. The first surface protection layer PL1 is not limited to this and may be formed from polymer materials such as quartz, polyimide, or polycarbonate.

[0116] As shown in Figures 24 and 25(b), the second sensor layer 22B includes a second sensor electrode layer SE2 made of a conductive layer laminated on the second main surface S2 of the base substrate 20, and a second surface protection layer PL2 laminated on the second sensor electrode layer SE2. The second sensor electrode layer SE2 has a plurality of second sensor electrodes PX2 and a plurality of second wirings WL2 formed by patterning the conductive layer. The second sensor layer 22B has, for example, a rectangular detection region SA and a peripheral region (non-detection region) BE located around the detection region SA.

[0117] Multiple second sensor electrodes PX2 are provided in the detection region SA. The multiple second sensor electrodes PX2 are arranged in a matrix along the first direction X and the second direction Y. For example, if the first direction X is the row and the second direction is the column, the second sensor electrodes PX2 are arranged in a 5x5 matrix. Each second sensor electrode PX2 is, in one example, composed of a rectangular planar pattern. The second sensor electrodes PX2 are made of metals such as titanium, molybdenum, and copper, or alloys containing one or more of these metals. However, the second sensor electrodes PX2 may also be made of a translucent conductive material such as indium-tin mixed oxide (ITO) or indium-zinc mixed oxide (IZO).

[0118] Multiple second wirings WL2 are provided in the gaps between the non-detection region BE and the rows of second sensor electrodes PX2; in this case, five wirings are provided in each gap. One end of each second wiring WL2 is connected to the corresponding second sensor electrode PX2, and the other end extends through the peripheral region BE to the protrusion 20c. In one example, the other end of each second wiring WL2 is electrically connected to the first connector CN1 on the first main surface S1 side via plated through-holes MH5 formed in the base substrate 20.

[0119] The second surface protection layer PL2 is an insulating protective layer and is laminated on the first main surface S1 of the base substrate 20, superimposed on the second sensor electrode PX2 and the second wiring WL2. In one example, solder resist can be used as the second surface protection layer PL2. The second surface protection layer PL2 is not limited to this and may be formed from polymer materials such as quartz, polyimide, or polycarbonate.

[0120] In this embodiment, the dimensions, number, and arrangement of the second sensor electrodes PX2 are set to be the same as those of the first sensor electrodes PX1. As a result, the multiple first sensor electrodes PX1 face the multiple second sensor electrodes PX2 with the base substrate 20 in between.

[0121] As shown in Figures 23 and 24, the detection circuit board 14 comprises a printed circuit board 15 and a plurality of electronic components or semiconductor elements mounted on the printed circuit board 15. In one example, the detection circuit board 14 includes a semiconductor element SD1 that constitutes an AFE circuit 24 that performs hover detection based on a detection signal from the sensor board 12, and a semiconductor element SD2 that constitutes a control circuit 25 that controls the hover detection operation. The control circuit 25 includes, for example, an MCU.

[0122] The detection circuit board 14 has a second connector CN2 and a third connector CN3 mounted on a printed circuit board 15. The first connector CN1 of the sensor board 12 and the second connector CN2 of the detection circuit board 14 are electrically connected by an FPC 18. As a result, the first sensor layer 22A and the second sensor layer 22B of the sensor board 12 are electrically connected to the detection circuit board 14 via the first connector CN1, the FPC 18, and the second connector CN2. The external control device (host) 16 is electrically connected to the detection circuit board 14 via the FPC 17 and the third connector CN3. The external control device (host) 16 can be any terminal capable of receiving hover operations in the hover detection device 10.

[0123] The detection circuit board 14 further includes an analog switch (SW) 66 mounted on a printed circuit board 15. The analog switch 66 is connected between the AFE circuit 24 and the second connector CN2, and between the MCU 25 and the second connector CN2. For example, a low-capacitance switch of about 8 pF can be used as the analog switch 66. The analog switch 66 is switched between a first selection position and a second selection position under the control of the MCU 25. In the first selection position of the analog switch 66, the first sensor electrode PX1 is connected to the AFE circuit 24, and the second sensor electrode PX2 is connected to GND2. In the second selection position, the second sensor electrode PX2 is connected to the AFE circuit 24, and the first sensor electrode PX1 is connected to GND2.

[0124] Furthermore, the detection circuit board 14 has the same configuration as the detection circuit board 14 shown in Figure 9. That is, the detection circuit board 14 further includes a power supply (PW1) for supplying a drive voltage, a reference potential generation circuit (26) for generating a reference potential, etc., which are not shown. The AFE circuit 24 performs hover detection based on the detection signal from the first sensor layer 22A or the detection signal from the second sensor layer 22B.

[0125] The detection circuit board 14, under the control of the MCU 25, switches the analog switch (SW) 66 to alternately connect the AFE circuit 24 to the first sensor layer 22A and the second sensor layer 22B. Figure 26 is a schematic diagram showing the connection relationship when the analog switch 66 is switched. As shown in the figure, when hover detection is performed by the first sensor layer 22A, the analog switch 66 is switched to the first selected position, connecting the first sensor electrode PX1 of the first sensor layer 22A to the AFE circuit 24. As a result, the drive signal AS1 and the detection signal RX1 are transmitted and received between the first sensor electrode PX1 and the AFE circuit 24. During this time, the second sensor electrode PX2 of the second sensor layer 22B is connected to the second reference potential GND2 via the analog switch 66. By applying the second reference potential GND2 to the second sensor electrode PX2, each of the multiple second sensor electrodes PX2 acts as a shield electrode (active shield).

[0126] Furthermore, when hover detection is performed by the second sensor layer 22B, the analog switch 66 is switched to the second selected position, connecting the second sensor electrode PX2 of the second sensor layer 22B to the AFE circuit 24. As a result, the drive signal AS1 and the detection signal RX1 are transmitted and received between the second sensor electrode PX2 and the AFE circuit 24. During this time, the first sensor electrode PX1 of the first sensor layer 22A is connected to the second reference potential GND2 via the analog switch 66. By applying the second reference potential GND2 to the first sensor electrode PX1, each of the multiple first sensor electrodes PX1 acts as a shield electrode (active shield).

[0127] During the detection operation, when the analog switch 66 is in the first selected position, the AFE circuit 24 generates a drive signal (reference signal or baseline current) AS1 under the control of the MCU 25 and outputs the drive signal AS1 to multiple first sensor electrodes PX1 via the analog switch 66. At the same timing as supplying the drive signal to the first sensor electrodes PX1, the AFE circuit 24 outputs a second reference potential GND2 to multiple second sensor electrodes PX2. Furthermore, in response to the drive signal, the AFE circuit 24 reads a detection signal Rx1 from each of the first sensor electrodes PX1, generates sensing data Tx based on the detection signal Rx1, and outputs it to the MCU 25.

[0128] During the detection operation, when the analog switch 66 is in the second selection position, the AFE circuit 24 generates a drive signal (reference signal or baseline current) AS1 under the control of the MCU 25 and outputs the drive signal AS1 to the multiple second sensor electrodes PX2 via the analog switch 66. At the same timing as supplying the drive signal to the second sensor electrodes PX2, the AFE circuit 24 outputs a second reference potential GND2 to the multiple first sensor electrodes PX1. Furthermore, in response to the drive signal, the AFE circuit 24 reads a detection signal Rx1 from each of the second sensor electrodes PX2, generates sensing data Tx based on the detection signal Rx1, and outputs it to the MCU 25.

[0129] Figure 27 is a flowchart showing an example of hover detection operation in a hover detection device according to the third embodiment. When power is supplied from the power source and the sensing operation by the hover detection device 10 starts (ST1), the hover detection device 10 performs a baseline scan (22A) to acquire a detection signal Rx1 from the first sensor layer 22A when the object to be detected is not in close proximity to the sensor substrate 12 (ST2). Next, the hover detection device 10 switches the analog switch 66 to the second selection position (ST3) and performs a baseline scan (22B) to acquire a detection signal Rx1 from the second sensor layer 22B (ST4).

[0130] After the baseline scan, the MCU 25 performs a hover detection operation (sensing) by alternating drive (ST5). Specifically, the MCU 25 generates a drive signal AS1 using the AFE circuit 24 with the analog switch 66 switched to the first selection position, and outputs the drive signal AS1 to a plurality of first sensor electrodes PX1 via the analog switch 66. At the same time, the AFE circuit 24 outputs a second reference potential GND2 to a plurality of second sensor electrodes PX2. Furthermore, the AFE circuit 24 reads a detection signal Rx1 from each of the first sensor electrodes PX1 in accordance with the drive signal, generates sensing data Tx based on the detection signal Rx1, and outputs it to the MCU 25. Next, the MCU 25 switches the analog switch 66 to the second selection position, and then performs the same sensing as above (22B) using the AFE circuit 24 and the second sensor layer 22B.

[0131] Next, the MCU 25 performs noise determination processing (ST6) and coordinate calculation processing (ST7) based on the difference between the detection signal Rx acquired by baseline scanning (ST2, ST4) and the detection signal R1 acquired by sensing (ST5). More specifically, the noise determination circuit 62 performs noise determination processing (ST6) based on the difference between the detection signal Rx acquired by baseline scanning and the detection signal Rx1 acquired by sensing. In Figure 27, an example is shown in which the coordinate calculation processing (ST7) is performed after the noise determination processing (ST6), but the noise determination processing may be performed after the coordinate calculation processing, or the noise determination processing and coordinate calculation processing may be performed in parallel.

[0132] Next, the MCU 25 determines whether the conditions for frequency hopping (hereinafter also simply referred to as "frequency hopping conditions") have been met (step S8). Specifically, the MCU 25 determines whether a signal including a frequency hopping command instructing the hover detection device 10 to perform frequency hopping has been input from the external control device (host) 16 connected via the FPC 17. Note that the frequency hopping conditions are not limited to those described above. For example, the MCU 25 may determine whether the frequency hopping conditions have been met.

[0133] If the frequency hopping condition is met in ST8, the MCU25 sets the drive frequency for hover detection, i.e., the fundamental frequency of the square wave signal Tx output from the AFE circuit24, to the frequency after frequency hopping (ST9).

[0134] If the frequency hopping condition is not met in ST8, and after frequency hopping is performed in ST9, the MCU 25 switches the analog switch 66 to the first selected position (ST10). Furthermore, the MCU 25 determines whether the sensing operation has finished (ST11), and if it has finished, it terminates the hover detection operation. Examples of when the sensing operation will finish include when power is no longer supplied from the power supply, or when a command to terminate the sensing operation is input to the hover detection device 10 from the host 16. If the sensing operation of the hover detection device 10 has not finished, the MCU 25 repeatedly executes the operations from ST5 onward.

[0135] Figure 28 is a timing chart showing an example of the operation of a frequency-hopping hover detection device 10 according to the third embodiment. As shown in the figure, the hover detection operation in the hover detection device 10 has a defined processing flow in units of repetition period Cy. First, a clock signal (V-Sync1) indicating the start of the repetition period Cy is output at a predetermined period. In one example, this clock signal is output at timings T1, T2, and T3. The following describes the flow of operation within the repetition period Cy, starting from timing T1.

[0136] Starting at timing T1, the analog switch (SW) is switched to the first selected position, and sensing operation (Sensing) is performed by the first sensor layer 22A corresponding to ST5 described above. The sensing operation by the first sensor layer 22A is performed during the period Pe1 from timing T1 until the start of the period Pe2 in which an interrupt signal (IRQ) indicating the end of the sensing operation is generated.

[0137] Between the end of period Pe2 and timing T2, periods Pe3, Pe4, Pe5, and Pe6 occur sequentially. Period Pe3 is the period during which sensing data output from the AFE circuit 24 is read (AFE Read). Period Pe4 is the period during which the noise determination process corresponding to ST6 and the coordinate calculation process corresponding to ST7 are executed in parallel. Period Pe5 is the period during which, if frequency hopping is performed, a command output (writing of information) is made to the AFE circuit 24 to set the fundamental frequency of the square wave signal Tx to the frequency after frequency hopping. Period Pe6 is a blank period from the end of period Pe5 to timing T2.

[0138] Starting at timing T2, the analog switch (SW) is switched to the second selected position, and sensing operation by the second sensor layer 22B begins. The sensing operation by the second sensor layer 22B is performed during the period Pe1 from timing T2 until the start of period Pe2, when an interrupt signal (IRQ) indicating the end of the sensing operation is generated.

[0139] Between the end of period Pe2 and timing T3, periods Pe3, Pe4, Pe5, and Pe6 occur sequentially. Period Pe3 is the period during which sensing data output from the AFE circuit 24 is read (AFE Read). Period Pe4 is the period during which the noise determination process corresponding to ST6 and the coordinate calculation process corresponding to ST7 are executed in parallel. Period Pe5 is the period during which, if frequency hopping is performed, a command output (writing of information) is made to the AFE circuit 24 to set the fundamental frequency of the square wave signal Tx to the frequency after frequency hopping. Period Pe6 is a blank period from the end of period Pe5 to timing T3.

[0140] Starting from timings T1 and T2, the operations of the above-described periods Pe1, Pe2, Pe3, Pe4, Pe5, and Pe6 are repeated again. Thereafter, each time a clock signal (V-Sync) indicating the start of the repeating period Cy is output at a predetermined interval, the above-described periods Pe1 to Pe6 are repeated.

[0141] According to the third embodiment configured as described above, a hover detection device can be provided that can be operated and hover detected from both sides of the sensor substrate 12, that is, from the side of the first sensor layer 22A and the side of the second shielding layer 22B. Furthermore, according to the third embodiment, by configuring the sensor substrate 12 with a substrate having two conductive layers and omitting an independent shielding electrode layer, the sensor substrate 12 can be made thinner and manufacturing costs can be reduced.

[0142] The following describes a modified version of the third embodiment. (Seventh Modification) Figure 29 is a cross-sectional view of the hover detection device according to the seventh modification. The sensor substrate 12 of the hover detection device 10 is not limited to a rigid circuit board, but may be made of a flexible printed circuit board (FPC) having a plurality of conductive layers. As shown in Figure 29, according to the seventh modification, the sensor substrate 12 is made of an FPC having two conductive layers, for example. More specifically, the sensor substrate 12 comprises a base substrate 20 made of an insulating layer formed of polyimide or the like, a first sensor layer 22A laminated on the first main surface S1 of the base substrate 20, and a second sensor layer 22B laminated on the second main surface S2 of the base substrate 20.

[0143] The first sensor layer 22A includes a first sensor electrode layer (conductive layer) SE1 laminated on the first main surface S1 of the base substrate 20, and a first surface protection layer PL1 laminated on the first sensor electrode layer SE1. The first sensor electrode layer SE1 includes a plurality of first sensor electrodes PX1 and a plurality of first wirings WL1 formed by patterning the conductive layer. In one example, the first surface protection layer PL1 is made of polyimide.

[0144] The second sensor layer 22B includes a second sensor electrode layer (conductive layer) SE2 laminated on the second main surface S2 of the base substrate 20, and a second surface protection layer PL2 laminated on the second sensor electrode layer SE2. The second sensor electrode layer SE2 includes a plurality of second sensor electrodes PX2 and a plurality of second wirings WL2 formed by patterning the conductive layer. In one example, the second surface protection layer PL2 is made of polyimide or the like.

[0145] One end of the sensor substrate 12 may be directly connected to the connector CN2 of the detection circuit board 14. The first sensor electrode layer SE1 and the second sensor electrode layer SE2 are electrically connected to the detection circuit board 14 via the connector CN2.

[0146] In the seventh modified example described above, the same effects and advantages as those of the third embodiment described above can be obtained. That is, in the seventh modified example as well, a detection device that can be operated and detected from both sides can be provided. Furthermore, by constructing the sensor substrate 12 using an FPC, it becomes possible to construct a flexible detection device. This increases the degree of freedom in installing the detection device and expands the range of applications.

[0147] (Eighth Modification) Figure 30 is a plan view showing the schematic configuration of the hover detection device according to the eighth modification, and Figure 31 is a cross-sectional view of the hover detection device according to the eighth modification. Figure 32 is a plan view schematically showing (a) the first sensor layer and (b) the second sensor layer of the hover detection device according to the eighth modification.

[0148] In the hover detection device 10 according to the eighth modified example, the sensor substrate 12 is constructed using two single-layer rigid circuit boards having the same structure. As shown in Figures 30 and 31, the hover detection device 10 includes the sensor substrate 12 and a detection circuit board 14 that drives the sensor substrate 12 and processes detection signals. The detection circuit board 14 is connected to an external control device (host computer) 16. The sensor substrate 12 has a first sensor layer 22A and a second sensor layer 22B, and these first sensor layer 22A and second sensor layer 22B are attached to each other back by an adhesive layer Ad. The first sensor layer 22A is a capacitive sensor array that detects the approach or contact of an object to be detected toward the first main surface S1. The second sensor layer 22B is a capacitive sensor array that detects the approach or contact of an object to be detected toward the second main surface S2.

[0149] As shown in Figures 31 and 32(a), the first sensor layer 22A includes a rigid base substrate 20a as a core material, a first sensor electrode layer SE1 consisting of a conductive layer laminated on the first main surface side of the base substrate 20a, and a first surface protection layer PL1 laminated on the first sensor electrode layer SE1. The first sensor electrode layer SE1 has a plurality of first sensor electrodes PX1 formed by patterning the conductive layer, a plurality of first wirings WL1, and a peripheral electrode AX1.

[0150] As shown in Figure 32(a), in one example, the base substrate 20a has a rectangular shape. Multiple first sensor electrodes PX1 are arranged in a matrix along the first direction X and the second direction Y. For example, if the first direction X is the row and the second direction is the column, the first sensor electrodes are arranged in a 4x4 matrix. Each first sensor electrode PX1 is, in one example, composed of a rectangular planar pattern. Multiple first sensor electrodes PX1 and surrounding electrodes AX1 are arranged symmetrically with respect to the central axis C1 of the second direction Y of the base substrate 20a. The number of electrodes in each row of the first direction X is set to an even number, for example, 4, 6, or 8.

[0151] The first sensor electrode PX1 is formed from a metal such as titanium, molybdenum, or copper, or an alloy containing one or more of these metals. The first sensor electrode PX1 may also be formed from a translucent conductive material such as indium-tin mixed oxide (ITO) or indium-zinc mixed oxide (IZO).

[0152] On the first main surface of the base substrate 20a, a connection terminal (not shown) and a first connector CN1 are provided along one end edge in the second direction Y. Multiple first wirings WL1 are provided in the non-detection region and the gaps between the rows of first sensor electrodes PX1, with four in this case, each extending in the second direction Y. One end of each first wiring WL1 is connected to the corresponding first sensor electrode PX1, and the other end extends through the peripheral region in the first direction X and is connected to the first connector CN1. The multiple first wirings WL1 and first connectors CN1 are formed and arranged symmetrically with respect to the central axis C1.

[0153] The first surface protection layer PL1 is an insulating protective layer and is laminated on the first main surface of the base substrate 20a, superimposed on the first sensor electrode PX1 and the first wiring WL1. In one example, solder resist can be used as the first surface protection layer PL1. The first surface protection layer PL1 is not limited to this and may be formed from polymer materials such as quartz, polyimide, or polycarbonate.

[0154] As shown in Figures 31 and 32(b), the second sensor layer 22B has the same configuration as the first sensor layer 22A. That is, the second sensor layer 22B includes a rigid base substrate 20b, a second sensor electrode layer SE2 consisting of a conductive layer laminated on the first main surface of the base substrate 20b, and a second surface protection layer PL2 laminated on the second sensor electrode layer SE2. The second sensor electrode layer SE2 has a plurality of second sensor electrodes PX2 formed by patterning the conductive layer, a plurality of second wirings WL2, and a peripheral electrode AX2. A connection terminal (not shown) and a fourth connector CN4 are provided along one end edge of the base substrate 20b in the second direction Y.

[0155] As shown in Figure 32(b), the second sensor electrodes PX2 are arranged in a 4x4 matrix. Each second sensor electrode PX2 is composed of a rectangular planar pattern of the same dimensions as the first sensor electrode PX1. The multiple second sensor electrodes PX2, multiple second wirings WL2, peripheral electrodes AX2, and fourth connector CN4 are formed and arranged symmetrically with respect to the central axis C1. As shown in Figure 31, the first sensor layer 22A and the second sensor layer 22B are laminated with the base substrates 20a and 20b facing each other and are bonded to each other by an adhesive layer Ad. As a result, the multiple first sensor electrodes PX1 are positioned facing the multiple second sensor electrodes PX2 in the third direction Z, with the base substrates 20a and 20b in between. Similarly, the first connector CN1 and the fourth connector CN4 are positioned facing each other in the third direction Z.

[0156] As shown in Figures 30 and 31, the detection circuit board 14 comprises a printed circuit board 15 and a plurality of electronic components or semiconductor elements mounted on the printed circuit board 15. In one example, the detection circuit board 14 includes a semiconductor element SD1 that constitutes an AFE circuit 24 that performs hover detection based on a detection signal from the sensor board 12, and a semiconductor element SD2 that constitutes a control circuit 25 that controls the hover detection operation. The control circuit 25 includes, for example, an MCU.

[0157] The detection circuit board 14 has a second connector CN2 and a third connector CN3 mounted on one main surface of the printed circuit board 15. The detection circuit board 14 also includes a fifth connector CN5 mounted on the other main surface of the printed circuit board 15. The fifth connector CN5 faces the second connector CN2 with the printed circuit board 15 in between. The first connector CN1 of the sensor board 12 and the second connector CN2 of the detection circuit board 14 are electrically connected by an FPC 18a. The fourth connector CN4 of the sensor board 12 and the fifth connector CN5 of the detection circuit board 14 are electrically connected by an FPC 18b. As a result, the first sensor layer 22A and the second sensor layer 22B of the sensor board 12 are electrically connected to the detection circuit board 14 via the connectors and FPCs 18a and 18b. The external control device (host) 16 is electrically connected to the detection circuit board 14 via an FPC 17 and the third connector CN3.

[0158] In addition, the detection circuit board 14 includes an analog switch (SW) 66 for switching the AFE circuit 24, a power supply (not shown), a reference potential generation circuit, etc. Similar to the third embodiment described above, in this modified example 8, the detection circuit board 14 switches the analog switch (SW) 66 under the control of the MCU 25 to alternately conduct the first sensor layer 22A and the second sensor layer 22B to the AFE circuit 24. That is, the detection circuit board 14 is configured to perform alternating drive, which alternately drives the first sensor layer 22A and the second sensor layer 22B.

[0159] In the eighth modified example configured as described above, a detection device can be provided that can be operated and detected from both sides, that is, from both the side of the first sensor layer 22A and the side of the second sensor layer 22B. Furthermore, according to this modified example, since the sensor substrate 12 can be constructed using two sensor layers with a common structure, it is possible to reduce the number of parts and manufacturing costs. In this case, by forming and arranging the sensor electrodes, wiring, and connectors symmetrically in each sensor layer, the first and second sensor electrodes PX1 and PX2 can be arranged facing each other when one sensor layer is positioned in an inverted direction relative to the other sensor layer. In the eighth modified example, the base substrate 20a of the first sensor layer 22A and the base substrate 20b of the second sensor layer 22B may be directly joined to each other by fixing means such as screws, without using the adhesive layer Ad.

[0160] (9th Modification) Figure 33 is a schematic plan view showing (a) the first sensor layer and (b) the second sensor layer of the hover detection device according to the 9th modification. Figure 34 is a cross-sectional view of the hover detection device according to the 9th modification. In the hover detection device 10 according to the 9th modification, the sensor substrate 12 is constructed using two single-layer flexible printed circuit boards (FPCs) having the same structure. As shown in Figure 34, the hover detection device 10 includes the sensor substrate 12 and a detection circuit board 14 that drives the sensor substrate 12 and processes the detection signal. The detection circuit board 14 is connected to an external control device (host computer) 16. The sensor substrate 12 has a first sensor layer 22A and a second sensor layer 22B, and these first sensor layer 22A and second sensor layer 22B are bonded together by an adhesive layer Ad.

[0161] The first sensor layer 22A includes a base substrate 20a made of an insulating layer formed of polyimide or the like, a first sensor electrode layer SE1 made of a conductive layer laminated on the first main surface side of the base substrate 20a, and a first surface protection layer PL1 made of polyimide or the like and laminated on the first sensor electrode layer SE1. The first connector CN1 is mounted on the second main surface of the base substrate 20a. The second sensor layer 22B is configured in the same way as the first sensor layer 22A. That is, the second sensor layer 22B includes a base substrate 20b made of an insulating layer formed of polyimide or the like, a second sensor electrode layer SE2 made of a conductive layer laminated on the first main surface side of the base substrate 20b, and a second surface protection layer PL2 made of polyimide or the like and laminated on the second sensor electrode layer SE2. The fourth connector CN4 is mounted on the second main surface of the base substrate 20b. In the ninth modified example, the first sensor layer 22A and the second sensor layer 22B are laminated in a manner in which the first surface protection layer PL1 and the second surface protection layer PL2 face each other, and the first surface protection layer PL1 and the second surface protection layer PL2 are bonded together by an adhesive layer Ad.

[0162] As shown in Figure 33(a), in one example, the base substrate 20a has a rectangular shape. The base substrate 20a integrally has a protrusion 20c that projects in a second direction Y from one side edge. On the first main surface of the base substrate 20a, a connection terminal (not shown) is provided on the protrusion 20c. Also, on the second main surface of the base substrate 20a, a first connector CN1 is provided on the protrusion 20c.

[0163] Multiple first sensor electrodes PX1 are arranged in a matrix along the first direction X and the second direction Y. For example, the first sensor electrodes are arranged in a 4x4 matrix. Each first sensor electrode PX1 is, in one example, composed of a rectangular planar pattern. Multiple first sensor electrodes PX1 and surrounding electrodes AX1 are arranged symmetrically with respect to the central axis C1 of the base substrate 20a in the second direction Y. The number of electrodes in each row in the first direction X is set to an even number, for example, 4, 6, or 8.

[0164] Multiple first wirings WL1 are provided in the gaps between the non-detection areas and the rows of first sensor electrodes PX1, with four in this case, and each extends in the second direction Y. One end of each first wiring WL1 is connected to the corresponding first sensor electrode PX1, and the other end extends through the peripheral area to the protrusion 20c and is connected to the first connector CN1 via a through-hole (not shown). The multiple first wirings WL1 and first connector CN1 are formed and arranged symmetrically with respect to the central axis C1. The first surface protective layer PL1 is an insulating protective layer and is laminated on the first main surface of the base substrate 20a, superimposed on the first sensor electrodes PX1 and the first wirings WL1.

[0165] As shown in Figure 33(b), the second sensor layer 22B has the same configuration as the first sensor layer 22A. That is, the base substrate 20b has a rectangular shape. The base substrate 20b integrally has a protrusion 20c that projects in the second direction Y from one side edge. On the first main surface of the base substrate 20b, a connection terminal (not shown) is provided on the protrusion 20c. Also, on the second main surface of the base substrate 20b, a fourth connector CN4 is provided on the protrusion 20c.

[0166] Multiple second sensor electrodes PX2 are arranged in a 4x4 matrix. Each second sensor electrode PX2 is composed of a rectangular planar pattern. Multiple second sensor electrodes PX2 and surrounding electrodes AX2 are arranged symmetrically with respect to the central axis C1 of the base substrate 20b in the second direction Y. The number of electrodes in each row in the first direction X is set to an even number, for example, 4, 6, or 8.

[0167] Four second wirings WL2 are provided in the gaps between the non-detection regions and the rows of second sensor electrodes PX2, and each extends in the second direction Y. One end of each second wiring WL2 is connected to the corresponding second sensor electrode PX2, and the other end extends through the peripheral region to the protrusion 20c and is connected to the fourth connector CN4 via a through-hole (not shown). The multiple second wirings WL2 and the fourth connector CN4 are formed and arranged symmetrically with respect to the central axis C1. The second surface protective layer PL2 is an insulating protective layer and is laminated on the first main surface of the base substrate 20a, superimposed on the second sensor electrodes PX2 and the second wirings WL2.

[0168] As shown in Figure 34, the first sensor layer 22A and the second sensor layer 22B are laminated with the first surface protection layer PL1 and the second surface protection layer PL2 facing each other, and are attached to each other by an adhesive layer Ad. As a result, the multiple first sensor electrodes PX1 are positioned facing the multiple second sensor electrodes PX2 in the third direction Z, with the first surface protection layer PL1 and the second surface protection layer PL2 in between. Similarly, the first connector CN1 and the fourth connector CN4 are arranged on the outer surfaces of the base substrates 20a and 20b, respectively, and are positioned facing each other in the third direction Z.

[0169] The detection circuit board 14 is configured in the same way as the detection circuit board 14 in the eighth modified example described above. The first connector CN1 of the sensor board 12 and the second connector CN2 of the detection circuit board 14 are electrically connected by an FPC 18a. The fourth connector CN4 of the sensor board 12 and the fifth connector CN5 of the detection circuit board 14 are electrically connected by an FPC 18b. As a result, the first sensor layer 22A and the second sensor layer 22B of the sensor board 12 are electrically connected to the detection circuit board 14 via the connectors and FPCs 18a and 18b. The external control device (host) 16 is electrically connected to the detection circuit board 14 via an FPC 17 and a third connector CN3. Note that if the sensor board 12 is formed of an FPC, the first connector CN1 and the fourth connector CN4 may be omitted, and the ends of the sensor board 12 may be directly connected to the connectors CN2 and CN5 of the detection circuit board 14.

[0170] In the ninth modified example configured as described above, a detection device can be provided that can be operated and detected from both sides, that is, from both the side of the first sensor layer 22A and the side of the second sensor layer 22B. Furthermore, according to this modified example, since the sensor substrate 12 can be constructed using two sensor layers with a common structure, it is possible to reduce the number of parts and manufacturing costs. In this case, by forming and arranging the sensor electrodes, wiring, and connectors symmetrically in each sensor layer, the first and second sensor electrodes PX1 and PX2 can be arranged facing each other when one sensor layer is placed in an inverted direction relative to the other sensor layer. Moreover, by constructing the sensor substrate 12 using an FPC, it is possible to construct a flexible detection device. This increases the degree of freedom in installing the detection device and expands the range of applications.

[0171] (Tenth Modification) Figure 35 is a cross-sectional view of the hover detection device according to the tenth modification. According to the ninth modification described above, the FPC constituting the first sensor layer 22A and the FPC constituting the second sensor layer 22B are stacked in opposite directions. That is, the first sensor layer 22A is inverted, with the first surface protection layer PL1 of the first sensor layer 22A facing the second surface protection layer PL2 of the second sensor layer 22B. As a result, the first connector CN1 and the fourth connector CN4 are arranged on the outer surface side of the sensor substrate 12.

[0172] In contrast, according to the tenth modified example, as shown in Figure 35, the FPC constituting the first sensor layer 22A and the FPC constituting the second sensor layer 22B are stacked in the same orientation. That is, both the first sensor layer 22A and the second sensor layer 22B are stacked with their front and back sides reversed, and the first surface protection layer PL1 of the first sensor layer 22A faces the base substrate 20b of the second sensor layer 22B. The first surface protection layer PL1 is attached to the base substrate 20b by an adhesive layer Ad. As a result, the fourth connector CN4 of the second sensor layer 22B is located approximately in the center of the thickness direction of the sensor substrate 12. That is, the fourth connector CN4 is located between the first surface protection layer PL1 of the first sensor layer 22A and the base substrate 20b of the second sensor layer 22B.

[0173] The first connector CN1 of the sensor board 12 and the second connector CN2 of the detection circuit board 14 are electrically connected by an FPC 18a. The fourth connector CN4 of the sensor board 12 and the fifth connector CN5 of the detection circuit board 14 are electrically connected by an FPC 18b. As a result, the first sensor layer 22A and the second sensor layer 22B of the sensor board 12 are electrically connected to the detection circuit board 14 via the connectors and FPCs 18a and 18b. In the tenth modified example, the other configurations of the hover detection device 10 are the same as those of the hover detection device according to the ninth modified example described above.

[0174] In the tenth modified example configured as described above, the same effects and advantages as those of the ninth modified example described above can be obtained. In the tenth modified example as well, if the sensor substrate 12 is formed of an FPC, the first connector CN1 and the fourth connector CN4 may be omitted, and the ends of the sensor substrate 12 may be directly connected to the connectors CN2 and CN5 of the detection circuit board 14.

[0175] While embodiments and modifications of the present invention have been described, these embodiments and modifications are presented as examples only and are not intended to limit the scope of the invention. Novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. Embodiments and their modifications are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. All configurations that a person skilled in the art can implement by appropriately modifying the design based on the above-described configurations as embodiments of the present invention also fall within the scope of the present invention, insofar as they encompass the spirit of the invention.

[0176] For example, the shape, dimensions, and number of sensor electrodes on the sensor substrate can be changed in various ways, without being limited to the embodiments described above. The constituent materials, dimensions, and shape of the sensor substrate can also be changed as appropriate, without being limited to the embodiments or modified versions described above.

Claims

1. A detection device comprising: a sensor substrate having a first sensor layer including a plurality of first sensor electrodes and a plurality of first wirings connected to the plurality of first sensor electrodes, and a second sensor layer provided opposite to the first sensor layer, including a plurality of second sensor electrodes and a plurality of second wirings connected to the plurality of second sensor electrodes; a controller having a first detection circuit that supplies drive signals to the plurality of first sensor electrodes via the plurality of first wirings and acquires and processes detection signals output from the first sensor electrodes; and a second detection circuit that supplies drive signals to the plurality of second sensor electrodes via the plurality of second wirings and acquires and processes detection signals output from the second sensor electrodes.

2. The detection device according to claim 1, wherein the controller includes a coordinate calculation circuit that determines the coordinate position of a subject approaching the first sensor layer based on a detection signal processed by the first detection circuit, and determines the coordinate position of a subject approaching the second sensor layer based on a detection signal processed by the second detection circuit.

3. The detection device according to claim 2, wherein the sensor substrate further comprises a base substrate having a first main surface and a second main surface facing the first main surface, the first sensor layer includes a first shield electrode layer laminated on the first main surface, a first insulating layer laminated on the first shield electrode layer, a first sensor electrode layer laminated on the first insulating layer and having a plurality of first sensor electrodes, and a first surface protection layer laminated on the first sensor electrode layer, and the second sensor layer includes a second shield electrode layer laminated on the second main surface, a second insulating layer laminated on the second shield electrode layer, a second sensor electrode layer laminated on the second insulating layer and having a plurality of second sensor electrodes, and a second surface protection layer laminated on the second sensor electrode layer.

4. The detection device according to claim 3, wherein the first shield electrode layer includes a plurality of first shield electrodes that are electrically conductive to each other and are provided opposite to the plurality of first sensor electrodes, and a plurality of first wirings arranged alongside the first shield electrodes, and the plurality of first wirings are each connected to the first sensor electrodes via through holes formed in the first insulating layer.

5. The detection device according to claim 4, wherein the second shield electrode layer includes a plurality of second shield electrodes that are electrically conductive to each other and each face the second sensor electrode, and a plurality of second wirings arranged alongside the second shield electrodes, the plurality of second wirings each connected to the second sensor electrode via through holes formed in the second insulating layer.

6. The detection device according to claim 5, wherein the controller includes a control circuit that applies a voltage of a predetermined potential to the first shield electrode and the second shield electrode in synchronization with the drive signal.

7. The detection device according to claim 1, further comprising: a controller, a switch for switching the connections between the first sensor layer and the second sensor layer and the first detection circuit and the second detection circuit; and a control circuit for switching the switch to alternately drive the first sensor layer and the second sensor layer.

8. The detection device according to claim 1, wherein the number of electrodes of the first sensor electrode is the same as the number of electrodes of the second sensor electrode.

9. The detection device according to claim 1, wherein the number of electrodes of the first sensor electrode is different from the number of electrodes of the second sensor electrode.

10. The detection device according to claim 5, wherein the first sensor layer is disposed on the first shield electrode layer and has a first connector connected to the first wiring and the first shield electrode, the plurality of second wirings and the second shield electrode of the second sensor layer are connected to the first connector via through holes formed in the base substrate, and the controller has a second connector connected to the first connector.

11. The detection device according to claim 5, wherein the first sensor layer is disposed on the first shield electrode layer and has a first wiring and a first connector connected to the first shield electrode, the second sensor layer is disposed on the second shield electrode layer and has a second wiring and a fourth connector connected to the second shield electrode, and the controller has a second connector connected to the first connector and a fifth connector connected to the fourth connector.

12. The detection device according to claim 5, wherein the controller comprises a printed circuit board formed integrally with the sensor board and a plurality of electronic components mounted on the printed circuit board.

13. The detection device according to claim 3, wherein the first sensor layer is made up of a flexible printed circuit board having the first insulating layer, a conductive layer provided on the first insulating layer and constituting a first sensor electrode layer including the first sensor electrode and the first wiring, and an insulating layer laminated on the conductive layer and constituting a first surface protection layer, and a conductive layer constituting a shield electrode is provided on the side of the first insulating layer opposite to the first sensor electrode layer, and the second sensor layer is made up of a flexible printed circuit board having the second insulating layer, a conductive layer provided on the second insulating layer and constituting a second sensor electrode layer including the second sensor electrode and the second wiring, and an insulating layer laminated on the conductive layer and constituting a second surface protection layer, and the second insulating layer is arranged opposite the shield electrode and attached to the shield electrode and the first insulating layer by an adhesive layer.

14. The detection device according to claim 3, wherein in the first sensor layer, the first insulating layer is formed of a transparent first adhesive layer, the first sensor electrode layer is formed of a transparent conductive layer having the plurality of first sensor electrodes and the plurality of first wirings, and the first surface protective layer is formed of a transparent protective layer; in the second sensor layer, the second insulating layer is formed of a transparent second adhesive layer, the second sensor electrode layer is formed of a transparent conductive layer having the plurality of first sensor electrodes and the plurality of first wirings, and the first surface protective layer is formed of a transparent protective layer; and the first adhesive layer is attached to the second adhesive layer with a shield electrode made of a transparent conductive layer sandwiched in between.

15. The detection device according to claim 2, wherein the first sensor layer comprises a base substrate having a first main surface and a second main surface facing the first main surface, a first conductive layer laminated on the first main surface to form the plurality of first sensor electrodes and the plurality of first wirings, and a first surface protection layer laminated on the first conductive layer; the second sensor layer comprises the base substrate, a second conductive layer laminated on the second main surface to form the plurality of second sensor electrodes and the plurality of second wirings, and a second surface protection layer laminated on the second conductive layer; and the controller comprises a switch for switching the connection between the first sensor layer and the second sensor layer and the first detection circuit and the second detection circuit, and a control circuit for switching the switch to alternately supply drive signals to the first sensor electrode and the second sensor electrode, and in synchronization with the drive signals to alternately apply a voltage of a predetermined potential to the second sensor electrode and the first sensor electrode.

16. The detection device according to claim 15, wherein the base substrate, the first surface protective layer, and the second surface protective layer are formed of a rigid insulating layer.

17. The detection device according to claim 15, wherein the base substrate, the first surface protective layer, and the second surface protective layer are formed of a flexible insulating layer.

18. The detection device according to claim 15, wherein the first sensor layer comprises a first base substrate having a first main surface and a second main surface facing the first main surface, a first conductive layer laminated on the first main surface to form the plurality of first sensor electrodes and the plurality of first wirings, and a first surface protection layer laminated on the first conductive layer, wherein the plurality of first sensor electrodes and the plurality of first wirings are arranged and formed symmetrically with respect to the central axis of the first base substrate, and the second sensor layer comprises a second base substrate having a first main surface and a second main surface facing the first main surface, a second conductive layer laminated on the first main surface of the second base substrate to form the plurality of second sensor electrodes and the plurality of second wirings, and a second surface protection layer laminated on the second conductive layer, wherein the plurality of second sensor electrodes and the plurality of second wirings are arranged and formed symmetrically with respect to the central axis of the second base substrate.

19. The detection device according to claim 18, wherein the first sensor layer and the second sensor layer are positioned opposite to each other, and the plurality of first sensor electrodes and the plurality of first wirings are positioned opposite to the plurality of second sensor electrodes and the plurality of second wirings, respectively.

20. The detection device according to claim 19, wherein the first base substrate, the first surface protective layer, the second base substrate, and the second surface protective layer are each formed of a rigid insulating layer, and the second main surface of the first base substrate is bonded to the second main surface of the second base substrate.

21. The detection device according to claim 19, wherein the first base substrate, the first surface protective layer, the second base substrate, and the second surface protective layer are each formed of a flexible insulating layer, and the first surface protective layer and the second surface protective layer face each other and are joined to each other.

22. The detection device according to claim 19, wherein the first base substrate, the first surface protective layer, the second base substrate, and the second surface protective layer are each formed of a flexible insulating layer, and the first surface protective layer and the second main surface of the second base substrate face each other and are joined together.

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