pressure sensor

Abstract

The present invention provides a pressure sensor that prevents crosstalk and includes a sensor layer on an array substrate. The pressure sensor comprises: an array substrate having a plurality of array electrodes on a first surface; an opposing substrate having an opposing surface opposite the first surface; a guard electrode disposed on the first surface and extending between the array electrodes; a sensor layer composed of a conductive elastomer that overlaps the first surface, the array electrodes, and the guard electrode; and a common electrode disposed on the opposing surface. The array substrate and the guard electrode are at the same potential.

Description

Technical Field

[0001] The present invention relates to a pressure sensor. Background Art

[0002] The pressure sensor includes an array substrate provided with a plurality of array electrodes, and an opposing substrate supporting a common electrode opposite to the array electrodes. The opposing substrate is a base material for pressure input, and is sometimes referred to as a protective film. A sensor layer covering the common electrode is provided on the surface of the opposing substrate opposite to the array electrodes. In the following patent document, the sensor layer uses a conductive elastomer in which a conductive material is mixed with a rubber material as an insulator. The conductive elastomer has the property that its resistance decreases if deformed. In addition, in the following patent document, when no pressure is input to the opposing substrate, the sensor layer is isolated from the array substrate. Therefore, when pressure is input to the opposing substrate, the sensor layer contacts the array electrodes. Then, the sensor layer is electrically connected to the array electrodes, and current flows from the common electrode to the array electrodes.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2018-44937 Summary of the Invention

[0006] In recent years, to simplify the manufacturing process and improve the precision of lamination between the counter substrate and the array substrate, research has explored placing the sensor layer above the array electrodes. However, placing the sensor layer above the array electrodes causes current to flow in a direction parallel to the sensor layer, resulting in crosstalk. Alternatively, to prevent crosstalk, the use of anisotropic conductive films, which allow current to flow only through the thickness of the sensor layer, as the sensor layer has been considered. However, considering dynamic range, a sensor layer made of a conductive elastomer is more desirable.

[0007] An object of the present invention is to provide a pressure sensor that prevents crosstalk and has a sensor layer on an array substrate.

[0008] A pressure sensor according to one aspect of the present disclosure includes: an array substrate having a plurality of array electrodes provided on a first surface; an opposing substrate having an opposing surface opposite the first surface; a guard electrode disposed on the first surface and extending between the array electrodes; a sensor layer composed of a conductive elastomer and overlapping the first surface, the array electrodes, and the guard electrode; and a common electrode provided on the opposing surface. The array substrate and the guard electrode are at the same potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a perspective view schematically showing the pressure sensor according to the first embodiment.

[0010] Figure 2 Observe from the direction of the arrow Figure 1 A sectional view of the section cut along line II-II.

[0011] Figure 3 This is a circuit diagram showing the circuit configuration of the pressure sensor according to the first embodiment.

[0012] Figure 4 This is a plan view of the array substrate according to Embodiment 1 as viewed from the sensor layer.

[0013] Figure 5 This is a cross-sectional view showing a state in which the detection surface of the pressure sensor according to Embodiment 1 is pressed.

[0014] Figure 6 is shown with Figure 5 A cross-sectional view of a case where the device is pressed with a greater force than in the state of FIG.

[0015] Figure 7 It is a cross-sectional view showing a case where the array electrode pressing the individual detection area is not connected to the signal line.

[0016] Figure 8 This is a cross-sectional view of a modified example of the pressure sensor according to the first embodiment.

[0017] Figure 9 This is a plan view of the array substrate of the pressure sensor of Modification 1 as viewed from the sensor layer.

[0018] Figure 10 This is a plan view of the array substrate of the pressure sensor of Modification 2 as viewed from the sensor layer.

[0019] Figure 11 This is a plan view of the array substrate of the pressure sensor of Modification 3 as viewed from the sensor layer.

[0020] Figure 12 This is a plan view of an array substrate of a pressure sensor according to modification 4 of the sensor layer.

[0021] Figure 13 This is a plan view of the array substrate of the pressure sensor according to Modification 5 as viewed from the sensor layer.

[0022] Figure 14 This is a plan view of the array substrate of the pressure sensor according to Modification 6 as viewed from the sensor layer.

[0023] Figure 15 This is a plan view of the array substrate of the pressure sensor according to Embodiment 2 as viewed from the common electrode.

[0024] Figure 16The detection surface of the pressure sensor of the second embodiment is pressed. Figure 15 Cross-sectional view in the direction of arrows XVI-XVI.

[0025] Figure 17 The detection surface of the pressure sensor of the second embodiment is pressed. Figure 15 Cross-sectional view in the direction of arrow XVII-XVII.

[0026] Figure 18 This is a cross-sectional view showing a modified example of the pressure sensor according to the second embodiment.

[0027] Figure 19 This is a plan view of the array substrate of the pressure sensor of Modification 7 as viewed from the common electrode.

[0028] Figure 20 yes Figure 19 Cross-sectional view in the direction of arrow XX-XX.

[0029] Figure 21 This is a plan view of the array substrate of the pressure sensor according to Embodiment 3 as viewed from the common electrode.

[0030] Figure 22 yes Figure 21 Cross-sectional view in the direction of arrow XXII-XXII.

[0031] The description of the accompanying drawings is as follows:

[0032] 1. 1G, 1H, 1I pressure sensors

[0033] 1a Detection surface

[0034] 2 Detection Area

[0035] 3Surrounding areas

[0036] 4 individual detection areas

[0037] 4A Press individual detection areas

[0038] 4B Adjacent individual detection areas

[0039] 5 substrates

[0040] 6Array substrate

[0041] 6a Page 1

[0042] 10 array layers

[0043] 11 gate lines

[0044] 12 signal lines

[0045] 13 driving transistor

[0046] 20 array electrodes

[0047] 30, 30A, 30B, 30C, 30D, 30E guard electrodes

[0048] 31 1st protective electrode

[0049] 32 2nd protective electrode

[0050] 33 ring guard electrode

[0051] 34 Connect the guard electrode

[0052] 35 multiple protection electrodes

[0053] 36 cross protection electrodes

[0054] 40, 40G, 40H sensor layers

[0055] 41 divided sensor layer

[0056] 41A 1st division sensor layer

[0057] 41B 2nd division sensor layer

[0058] 42 protrusions

[0059] 50 shared electrodes

[0060] 60 protective film

[0061] 70 Opposite side sensor layer

[0062] 71A 3rd divided sensor layer (opposite divided sensor layer)

[0063] 71B 4th divided sensor layer (opposite side divided sensor layer) DETAILED DESCRIPTION

[0064] With reference to the accompanying drawings, the method (implementation method) for implementing the pressure sensor disclosed in the present invention is described in detail. The invention disclosed in the present invention is not limited by the contents described in the following embodiments. In addition, the constituent elements described below include constituent elements that can be easily thought of by those skilled in the art, and substantially the same constituent elements. Moreover, the constituent elements described below can be appropriately combined. In addition, the present disclosure is only an example, and appropriate changes that maintain the main purpose of the invention that can be easily thought of by those skilled in the art are of course included in the scope of the present invention. In order to make the description clearer, the width, thickness, shape, etc. of each part of the drawings are sometimes schematically shown compared to the actual form, but this is only an example and does not limit the interpretation of the present invention. In addition, in this specification and each figure, the same constituent elements as the constituent elements described in the drawings that have already appeared are sometimes marked with the same figure numerals, and detailed descriptions are appropriately omitted.

[0065] In addition, in this specification and the scope of patent protection, whenever the form of configuring another structure on a certain structure is expressed, when it is simply expressed as "on...", unless otherwise specified, it includes both the case where the other structure is configured directly above the certain structure in a manner of contacting the certain structure, and the case where the other structure is configured above the certain structure with another structure interposed therebetween.

[0066] (Implementation Method 1)

[0067] Figure 1 : is a perspective view schematically showing the pressure sensor of embodiment 1. Figure 1 As shown in FIG, the pressure sensor 1 is a plate-shaped device. One side of the pressure sensor 1 is a detection surface 1a. When the pressure sensor 1 is viewed from the normal direction of the detection surface 1a, the pressure sensor 1 forms a rectangular shape. The detection surface 1a of the pressure sensor 1 is divided into a detection area 2 that can detect the pressure acting on the detection surface 1a, and a peripheral area 3 surrounding the outside of the detection area 2. In addition, Figure 1 In FIG, a boundary line L is drawn to facilitate understanding of the boundary between the detection area 2 and the surrounding area 3.

[0068] The detection area 2 is divided into a plurality of individual detection areas 4. In other words, the detection area 2 is an area where a plurality of individual detection areas 4 are gathered. The plurality of individual detection areas 4 are arranged in the first direction Dx and the second direction Dy. The first direction Dx is a direction parallel to the detection surface 1a. The second direction Dy is a direction parallel to the detection surface 1a and intersecting with the first direction Dx. In the present embodiment, the first direction Dx is a direction parallel to the short side 1b of the pressure sensor 1. The second direction Dy is a direction parallel to the long side 1c of the pressure sensor 1. That is, in the present embodiment, the first direction Dx and the second direction Dy are orthogonal to each other. In addition, in the following description, the direction orthogonal to the first direction Dx and the second direction Dy (the thickness direction of the pressure sensor 1) is referred to as the third direction Dz.

[0069] Figure 2 Observe from the direction of the arrow Figure 1 A sectional view of the section cut along line II-II.

[0070] Figure 3 1 is a circuit diagram showing the circuit configuration of the pressure sensor of Embodiment 1. Figure 2 As shown, the pressure sensor 1 includes a substrate 5 , an array layer 10 , a protective electrode 30 , a sensor layer 40 , a common electrode 50 , and a protective film 60 .

[0071] The substrate 5 is an insulating substrate. For example, a glass substrate, a resin substrate, or a resin film can be used for the substrate 5. In the following description, the upper side refers to one direction in the third direction Dz, and refers to the side on which the array layer 10 is disposed, as viewed from the substrate 5. Furthermore, the lower side refers to another direction in the third direction Dz, and refers to the side on which the substrate 5 is disposed, as viewed from the array layer 10.

[0072] The array layer 10 is a layer having a plurality of array electrodes 20. The plurality of array electrodes 20 are arranged in the detection region 2 of the array layer 10. In addition, a plurality of driving transistors 13 are provided in the detection region 2 of the array layer 10. The array layer 10 has various structures for driving the driving transistors 13. Specifically, Figure 1 As shown, the array layer 10 includes a connection portion 7, a gate line driving circuit 8, a signal line selection circuit 9, and a gate line 11 (see Figure 3 ), and signal line 12 (refer to Figure 3 ). In addition, the array layer 10 and the substrate 5 are integrated to form the array substrate 6.

[0073] The connection portion 7, gate line driver circuit 8, and signal line selection circuit 9 are arranged in the peripheral region 3 of the array layer 10. The connection portion 7 is used to connect to a driver IC (Integrated Circuit) arranged outside the pressure sensor 1. In the present disclosure, the driver IC may be mounted as a COF (Chip on Film) on a flexible printed circuit board or a rigid substrate connected to the connection portion 7. Alternatively, the driver IC may be mounted as a COG (Chip on Glass) in the peripheral region 3 of the substrate 5.

[0074] The gate line driving circuit 8 drives the plurality of gate lines 11 based on various control signals from the driver IC (see Figure 3 ) circuit. The gate line driving circuit 8 selects a plurality of gate lines 11 sequentially or simultaneously and supplies gate driving signals to the selected gate lines 11. The signal line selecting circuit 9 selects a plurality of signal lines 12 sequentially or simultaneously (refer to Figure 3 The signal line selection circuit 9 is, for example, a multiplexer. The signal line selection circuit 9 connects the selected signal line 12 to the driver IC based on a selection signal supplied from the driver IC.

[0075] Figure 3 1 is a circuit diagram showing the circuit configuration of the pressure sensor of Embodiment 1. Figure 3 As shown, the gate line 11 extends in the first direction Dx within the array layer 10. Multiple gate lines 11 are arranged in the second direction Dy. The signal line 12 extends in the second direction Dy within the array layer 10. Multiple signal lines 12 are arranged in the first direction Dx.

[0076] A driving transistor 13 is provided in each individual detection region 4. Figure 2 As shown, the driving transistor 13 includes a semiconductor layer 13a, a gate insulating film 13b, a gate electrode 13c, a drain electrode 13d, and a source electrode 13e. The source electrode 13e is electrically connected to the array electrode 20. The gate electrode 13c is connected to the gate line 11. The drain electrode 13d is connected to the signal line 12. Thus, when the gate line 11 is scanned, the array electrode 20 is electrically connected to the signal line 12. Therefore, an electrical signal (current value) is input to the array electrode 20 via the signal line 12.

[0077] In addition, if Figure 1 As shown, common wiring 25 and common electrode wiring (not shown) are provided in the peripheral region 3 of the array layer 10. The common wiring 25 is used to supply a predetermined voltage to the common electrode 50 and extends along the peripheral region 3. The guard electrode wiring is used to supply a predetermined voltage to the guard electrode 30. The common wiring 25 and the guard electrode wiring (not shown) are connected to the driver IC via the connection portion 7, and a predetermined voltage is supplied from the driver IC.

[0078] like Figure 2 As shown, the first surface 6a of the array substrate 6 facing the protective film 60 is flattened by an insulating layer 14 covering the driving transistor 13 and the like. In addition, a spacer (not shown) is provided in the peripheral region 3 of the first surface 6a of the array substrate 6 to support the protective film 60.

[0079] Figure 4 This is a plan view of the array substrate of Embodiment 1 viewed from the sensor layer. The array electrode 20 and the protective electrode 30 are provided on the first surface 6a of the array substrate 6. The array electrode 20 and the protective electrode 30 are made of a metal material such as ITO (Indium Tin Oxide). Figure 4 As shown, the array electrode 20 is formed in a rectangular shape. The array electrode 20 is arranged in the first direction Dx and the second direction Dy and is disposed in the center of the individual detection area 4. The present disclosure is not limited to the configuration in which the array electrode is rectangular.

[0080] like Figure 4As shown, the guard electrode 30 includes a plurality of first guard electrodes 31 extending in the first direction Dx, and a plurality of second guard electrodes 32 extending in the second direction Dy. Furthermore, the plurality of first guard electrodes 31 are arranged at equal intervals in the first direction Dy. The plurality of second guard electrodes 32 are arranged at equal intervals in the second direction Dx. Thus, the guard electrode 30 divides the detection area 2 into a matrix. Furthermore, each area divided into the matrix by the guard electrode 30 corresponds to an individual detection area 4. In other words, the array electrode 20 is arranged inside the rectangular frame formed by the first guard electrodes 31 and the second guard electrodes 32.

[0081] Although not specifically shown in the figure, the end of the first guard electrode 31 in the first direction Dx extends toward the peripheral region 3. Furthermore, the end of the first guard electrode 31 in the first direction Dx is connected to a guard electrode wiring (not shown). Similarly, the end of the second guard electrode 32 in the second direction Dy extends toward the peripheral region 3. The end of the second guard electrode 32 in the second direction Dy is connected to a guard electrode wiring (not shown). Furthermore, a constant voltage is supplied from the driver IC to the first and second guard electrodes 31 and 32.

[0082] The sensor layer 40 is a conductive elastomer composed of an insulating rubber material (base material) mixed with a conductive material. When no pressure is applied to the sensor layer 40, the resistance is high. However, when pressure is applied to the sensor layer 40, the microparticles within the rubber material come into contact or closer together, causing the resistance of the sensor layer 40 to decrease. Furthermore, as the rubber material deforms, the contact between the microparticles increases, significantly reducing the resistance of the sensor layer 40.

[0083] like Figure 2 As shown, the sensor layer 40 overlaps with the first surface 6a of the array layer 10, the array electrode 20, and the protective electrode 30. That is, the sensor layer 40 is a whole-surface film (gapless film) that covers the first surface 6a, the array electrode 20, and the protective electrode 30 as a whole. Therefore, the array electrode 20 and the protective electrode 30 are in contact with the sensor layer 40. The edge of the sensor layer 40 extends to the peripheral area 3. In addition, the edge of the sensor layer 40 is fixed to the array layer 10 using an adhesive layer or double-sided tape not shown. In addition, in the present disclosure, the sensor layer 40 can be configured only in the detection area 2 and not extend to the peripheral area 3. In addition, the sensor layer 40 of the present disclosure can also be formed by coating on the first surface 6a of the array layer 10, etc.

[0084] The protective film 60 is a highly insulating and flexible substrate. In this disclosure, the protective film 60 is sometimes referred to as a counter substrate. The edges of the protective film 60 are fixed to spacers (not shown). This separates the protective film 60 from the array substrate 6 in the third direction Dz. The protective film 60 has a counter surface 61 facing the array substrate 6 and a detection surface 1a facing in the opposite direction from the counter surface 61.

[0085] The common electrode 50 is a solid-surface electrode formed entirely on the opposing surface 61 of the protective film 60. It is connected to the common wiring 25 provided in the peripheral region 3 of the first surface 6a of the array substrate 6. The common electrode 50 is isolated from the sensor layer 40. In other words, a gap S is provided between the common electrode 50 and the sensor layer 40. As a result, the common electrode 50 is insulated from the array electrode 20.

[0086] Next, the method of using the pressure sensor 1 will be described. The array electrode 20 and the guard electrode 30 are electrically connected via the sensor layer 40. In addition, when the pressure sensor 1 is used, a voltage having the same potential as the potential of the array electrode 20 is applied to the guard electrode 30 via the guard electrode wiring (not shown). Therefore, no current flows from the guard electrode 30 to the array electrode 20. In other words, even if there is no input pressure, the flow of current to the array electrode 20 is avoided. In addition, the potential of the array electrode 20 mentioned here refers to the potential of the array electrode 20 in a state where the gate drive signal is input to the gate line 11 and the signal line 12 is connected to the array electrode. On the other hand, a voltage is applied to the common electrode 50 via the common wiring 25 (see Figure 1 ) applies a voltage to form a reference potential. This reference potential is higher than the potential of the array electrode 20 and the guard electrode 30.

[0087] Figure 5 This is a cross-sectional view showing a state in which the detection surface of the pressure sensor according to Embodiment 1 is pressed. Figure 6 is shown with Figure 5 A cross-sectional view of a case where the device is pressed with a greater force than in the state of FIG. Figure 7 This is a cross-sectional view showing the case where the array electrodes of the pressed individual detection areas are not connected to the signal lines. Next, a case where a portion of the detection surface 1a of the pressure sensor 1 is pressed will be described. In the following description, the pressed area among the multiple individual detection areas 4 is referred to as the pressed individual detection area 4A, and the area adjacent to the pressed individual detection area 4A is referred to as the adjacent individual detection area 4B.

[0088] like Figure 5As shown, when the detection surface 1a of the pressure sensor 1 is pressed by the finger 200, a portion of the protective film 60 is deformed so as to protrude downward. As a result, the common electrode 50 contacts the sensor layer 40. In addition, when the array electrode 20 included in the individual pressure detection area 4A is connected to the signal line 12 (when the driving transistor 13 is turned on), it is electrically connected to the common electrode 50 via the sensor layer 40. Therefore, current flows to the array electrode 20 (refer to FIG. 1 ). Figure 5 As a result, the current value input to the array electrode 20 is output from the signal line 12.

[0089] In addition, the array electrodes 20 included in the individual press detection area 4A are surrounded by the guard electrodes 30 (the first guard electrode 31 and the second guard electrode 32). Therefore, the current also flows to the guard electrodes 30 (see FIG. 1 ) included in the individual press detection area 4A. Figure 5 Therefore, the current flowing from the common electrode 50 does not flow substantially outside the rectangular frame of the guard electrode 30. In other words, sufficient current to drive the array electrodes 20 as sensors does not flow to the array electrodes 20 included in the adjacent individual detection areas 4B.

[0090] In addition, when the pressure input to the detection surface 1a of the pressure sensor 1 is large, as shown in FIG. Figure 6 As shown, the downward protrusion of the protective film 60 increases. As a result, the sensor layer 40 deforms, concaving downward, reducing the resistance of the deformed portion of the sensor layer 40. Furthermore, the contact area between the common electrode 50 and the sensor layer 40 becomes arc-shaped in cross-section, increasing the contact area. Consequently, the current flowing through the array electrode 20 and the protective electrode 30 within the individual pressure detection area 4A increases.

[0091] On the other hand, Figure 7 As shown, when the array electrode 20 pressing the individual detection area 4A is not connected to the signal line 12 (when the driving transistor 13 is off), no current flows to the array electrode 20. However, the guard electrode 30 surrounding the array electrode 20 has a predetermined potential. Therefore, current flows to the guard electrode 30 (see Figure 7 arrows B1, B2).

[0092] Furthermore, when the array electrodes 20 included in the adjacent individual detection regions 4B are connected to the signal line 12 (when the driving transistor 13 is turned on), a current may flow from the common electrode 50 via the sensor layer 40 (see Figure 7(See dashed arrow B3). However, according to this embodiment, the guard electrode 30 is disposed between the contact portion between the common electrode 50 and the sensor layer 40 and the array electrode 20 included in the adjacent individual detection area 4B. Therefore, the current flowing from the common electrode 50 flows to the guard electrode 30 and hardly flows to the array electrode 20 included in the adjacent individual detection area 4B.

[0093] As described above, according to the pressure sensor 1 of the first embodiment, no current flows to the array electrodes 20 of the adjacent individual detection regions 4B that are not pressed, thereby avoiding crosstalk.

[0094] Figure 8 1 is a cross-sectional view of a modified example of the pressure sensor of embodiment 1. The pressure sensor 1 of embodiment 1 has been described above, but the pressure sensor of the present disclosure is not limited to a configuration in which the sensor layer 40 is provided only on the array substrate 6. Figure 8 As shown, the pressure sensor 1 may also include an opposing sensor layer 70 on the opposing surface 61 of the protective film 60. Furthermore, the opposing sensor layer 70 is a film that covers the entire opposing surface 61 and the common electrode 50. Even in this modified example, crosstalk can be suppressed in the same manner as in the first embodiment. Furthermore, in the pressure sensor disclosed herein, the guard electrode is not limited to the electrode illustrated in the first embodiment. The following describes a modified example of the guard electrode.

[0095] (Variation 1)

[0096] Figure 9 This is a plan view of the array substrate of the pressure sensor of Modification 1 viewed from the sensor layer. Figure 9 As shown, the guard electrode 30A of modification example 1 has a ring-shaped guard electrode 33. The ring-shaped guard electrode 33 is formed into a rectangular frame shape when viewed from the third direction Dz. In addition, the ring-shaped guard electrode 33 is located on the inner side of the individual detection area 4. In addition, the guard electrode 30A of modification example 1 does not extend to the peripheral area 3. Therefore, a contact hole is formed in the array layer 10, and a wiring for the guard electrode is provided in the contact hole to supply voltage to the guard electrode 30A. As described above, according to modification example 1, one side of two ring-shaped guard electrodes 33 is arranged between adjacent array electrodes 20. Therefore, compared with embodiment 1, it is more difficult for the guard electrode 30 to generate crosstalk. In addition, in the present disclosure, the ring-shaped guard electrode can also be formed into a circular frame shape.

[0097] (Variation 2)

[0098] Figure 10This is a plan view of the array substrate of the pressure sensor of Modification 2, viewed from the sensor layer. The guard electrode 30B of Modification 2 includes a plurality of first guard electrodes 31 extending in the first direction Dx, a plurality of second guard electrodes 32 extending in the second direction Dy, and a plurality of annular guard electrodes 33 forming a ring shape. In other words, the guard electrode 30B of Modification 1 combines the guard electrode 30 of Embodiment 1 with the guard electrode 30A of Modification 1. This further suppresses the generation of crosstalk.

[0099] (Variation 3)

[0100] Figure 11 This is a plan view of the array substrate of the pressure sensor of Modification 3, viewed from the sensor layer. The guard electrode 30C of Modification 3 includes multiple annular guard electrodes 33 and multiple connecting guard electrodes 34. The connecting guard electrodes 34 extend in the first direction Dx or the second direction Dy and connect the annular guard electrodes 33 to each other. Furthermore, the connecting guard electrodes 34 connect the guard electrode wiring (not shown) disposed in the peripheral region 3 to the annular guard electrodes 33. Therefore, according to Modification 3, there is no need to form contact holes in the array layer 10, making manufacturing easier.

[0101] (Variation 4)

[0102] Figure 12 This is a plan view of the array substrate of the pressure sensor according to Modification 4, viewed from the sensor layer. The guard electrode 30D of Modification 4 includes multiple first guard electrodes 31, multiple second guard electrodes 32, multiple annular guard electrodes 33, and multiple connecting guard electrodes 34. In Modification 4, the connecting guard electrodes 34 connect the annular guard electrodes 31 and the second guard electrodes 32. This allows a predetermined voltage to be supplied to the annular guard electrodes 33 via the first guard electrodes 31. Furthermore, since contact holes do not need to be formed in the array layer 10, manufacturing is simplified.

[0103] (Variant 5)

[0104] Figure 13This is a plan view of the array substrate of the pressure sensor of Modification 5, viewed from the sensor layer. The guard electrode 30E of Modification 5 includes a multi-layer guard electrode 35. The multi-layer guard electrode 35 includes three (or more) annular guard electrodes 33 centered around the array electrode 20. The multi-layer guard electrode 35 of Modification 5 includes a first annular guard electrode 33a surrounding the outside of the array electrode 20, a second annular guard electrode 33b surrounding the outer periphery of the first annular guard electrode 33a, and a third annular guard electrode 33c surrounding the outer periphery of the second annular guard electrode 33b, forming a three-layer structure. Furthermore, the widths of the first annular guard electrode 33a, the second annular guard electrode 33b, and the third annular guard electrode 33c are significantly narrower than those of the annular guard electrode 33 of Modification 1. With this multi-layer guard electrode 35, even if one of the three annular guard electrodes 33 is disconnected, the remaining annular guard electrodes 33 continue to function as annular guard electrodes 33.

[0105] (Variation 6)

[0106] Figure 14 This is a plan view of the array substrate of the pressure sensor according to Modification 6, viewed from the sensor layer. The guard electrode 30F of Modification 6 includes multiple multi-guard electrodes 35 and multiple connection guard electrodes 34. The connection guard electrodes 34 are connected to the first, second, and third annular guard electrodes 33a, 33b, and 33c of the multiple guard electrodes 35, respectively. Furthermore, the connection guard electrodes 34 are connected to guard electrode wiring via contact holes provided in the array layer 10. According to Modification 6, there is no need to form contact holes for each of the multiple annular guard electrodes 33, simplifying manufacturing.

[0107] Next, another embodiment of the pressure sensor disclosed herein will be described.

[0108] (Implementation Method 2)

[0109] Figure 15 This is a plan view of the array substrate of the pressure sensor according to Embodiment 2 as viewed from the common electrode. Figure 16 The detection surface of the pressure sensor of the second embodiment is pressed. Figure 15 Cross-sectional view in the direction of arrows XVI-XVI. Figure 17 The detection surface of the pressure sensor of the second embodiment is pressed. Figure 15 Cross-sectional view in the direction of arrow XVII-XVII. Figure 18 This is a cross-sectional view showing a modified example of the pressure sensor according to the second embodiment.

[0110] like Figure 15As shown, pressure sensor 1G of embodiment 2 differs from pressure sensor 1 of embodiment 1 in that it includes a sensor layer 40G instead of sensor layer 40 . Pressure sensor 1H of embodiment 2 also differs from pressure sensor 1 of embodiment 1 in that it includes a guard electrode 30G instead of guard electrode 30 .

[0111] The sensor layer 40G includes a plurality of divided sensor layers 41 divided in the first direction Dx. Each of the divided sensor layers 41 extends in the second direction Dy. Specifically, a single divided sensor layer 41 spans and overlaps with a plurality of array electrodes 20 arranged in the second direction Dy. Furthermore, the divided sensor layers 41 are isolated from one another. Specifically, gaps S1 are provided between the divided sensor layers 41. Consequently, the divided sensor layers 41 are insulated from one another.

[0112] The guard electrode 30G includes a plurality of crossing guard electrodes 36 extending in the first direction Dx. One crossing guard electrode 36 is provided between each of the array electrodes 20 adjacent to each other in the second direction Dy. Furthermore, when viewed from the third direction Dz (the common electrode 50), the crossing guard electrodes 36 intersect (are perpendicular to) the partitioned sensor layer 41.

[0113] According to the pressure sensor 1G of the second embodiment, when the detection surface 1a is pressed by the finger 200, Figure 16 As shown, the common electrode 50 contacts the divided sensor layer 41 within the range of the individual detection area 4A. As a result, the array electrode 20 pressing the individual detection area 4A is electrically connected to the common electrode 50. Therefore, current flows from the common electrode 50 to the array electrode 20 (see Figure 16 、 Figure 17 arrow C1).

[0114] In addition, if Figure 16 As shown, the array electrode 20 adjacent to the array electrode 20 in the first direction Dx relative to the pressed individual detection area 4A has a different divided sensor layer 41 overlapping the divided sensor layer 41 that contacts the common electrode 50. Therefore, when the individual detection area 4A is pressed, almost no current flows to the array electrode 20 in the adjacent individual detection area 4B adjacent to the array electrode 20 in the first direction Dx (see FIG. Figure 16 dotted arrows C2, C3).

[0115] In addition, if Figure 17 As shown, a cross guard electrode 36 is arranged between the array electrode 20 pressing the individual detection area 4A and the array electrode 20 adjacent to the array electrode 20 in the second direction Dy. Therefore, almost no current flows to the array electrode 20 of the adjacent individual detection area 4B adjacent to the pressing individual detection area 4A in the second direction Dy (see FIG. Figure 17 dotted arrows C4, C5).

[0116] As described above, the pressure sensor 1G according to the second embodiment suppresses crosstalk using the guard electrode 30G and the partitioned sensor layer 41 .

[0117] The pressure sensor 1G according to the second embodiment has been described above, but the pressure sensor of the present disclosure is not limited to the above-described sensor. Figure 18 As shown, the pressure sensor 1G of Embodiment 2 may also include an opposing sensor layer 70. This opposing sensor layer 70 is a solid film that covers the entire opposing surface 61 and the common electrode 50. The pressure sensor disclosed herein may also have different sensitivities for each of the divided sensor layers 41. Details are described below in Modification 7.

[0118] (Variant 7)

[0119] Figure 19 This is a plan view of the array substrate of the pressure sensor of Modification 7 as viewed from the common electrode. Figure 20 yes Figure 19 The XX-XX arrow direction cross-sectional view. Figure 19 As shown, the sensor layer 40H of the pressure sensor 1H of Modification 7 differs from that of Embodiment 2 in that it includes two types of sensor layers: a first divided sensor layer 41A and a second divided sensor layer 41B. Furthermore, the individual detection regions 4 of the pressure sensor 1H of Modification 7 differ from the pressure sensor 1G of Embodiment 2 in that they are elongated in the first direction Dx and include two array electrodes 20. Therefore, in the pressure sensor 1H of Modification 7, a pressing force (pressure) input to a single individual detection region 4 is input to both the first divided sensor layer 41A and the second divided sensor layer 41B.

[0120] The first divided sensor layers 41A and the second divided sensor layers 41B are alternately arranged in the first direction Dx. Therefore, the first divided sensor layer 41A overlaps one of the two array electrodes 20 included in one individual detection region 4, and the second divided sensor layer 41B overlaps the other.

[0121] like Figure 20As shown, the first divided sensor layer 41A and the second divided sensor layer 41B are provided with a protrusion 42 protruding upward. The front end of the protrusion 42 contacts (abuts) the common electrode 50. In addition, the contact area between the protrusion 42 and the common electrode 50 is narrow. Therefore, the first divided sensor layer 41A and the second divided sensor layer 41B ensure the insulation state between the common electrode 50 and the array electrode 20. On the other hand, if the detection surface 1a is pressed and the protrusion 42 is crushed (deformed), the resistance of the first divided sensor layer 41A and the second divided sensor layer 41B becomes smaller. In other words, the first divided sensor layer 41A and the second divided sensor layer 41B change from an insulating state to a conductive state.

[0122] Furthermore, the first divided sensor layer 41A has two protrusions 42. The second divided sensor layer 41B has one protrusion 42. Therefore, the pressure applied from the detection surface 1a to the protrusion 42 is distributed across the two protrusions 42 in the first divided sensor layer 41A. Therefore, even when the same pressure is applied, the second divided sensor layer 41B experiences a greater change.

[0123] In the pressure sensor 1H of Modification 7, the pressing force (pressure) input to the individual detection areas 4 is input separately to the first divided sensor layer 41A and the second divided sensor layer 41B. Furthermore, when the pressing force (pressure) is small, the two protrusions 42 of the first divided sensor layer 41A are not sufficiently crushed, maintaining the first divided sensor layer 41A in an insulated state. Consequently, no current flows to the array electrode 20 overlapping with the first divided sensor layer 41A. On the other hand, the protrusions 42 of the second divided sensor layer 41B are more crushed, placing the second divided sensor layer 41B in a conductive state. Consequently, current flows to the array electrode 20 overlapping with the second divided sensor layer 41B.

[0124] On the other hand, when a strong pressing force (pressure) is applied to the individual detection regions 4, the two protrusions 42 of the first segmented sensor layer 41A are significantly crushed, causing the first segmented sensor layer 41A to become conductive. Consequently, current flows through the array electrode 20 overlapping the first segmented sensor layer 41A. Furthermore, the protrusions 42 of the second segmented sensor layer 41B are also crushed, causing current to flow through the array electrode 20 overlapping the second segmented sensor layer 41B.

[0125] Then, in the pressure sensor 1H of Modified Example 7, the sensitivity of detectable pressure can be changed by selecting the signal line 12. That is, by selecting the signal line 12 connected to the array electrode 20 overlapping the second divided sensor layer 41B among the multiple signal lines 12, a small pressure can be detected. On the other hand, by selecting the signal line 12 connected to the array electrode 20 overlapping the first divided sensor layer 41A among the multiple signal lines 12, a large pressure can be detected. In other words, the range of detectable pressure (dynamic range) can be increased. In addition, in Modified Example 7, as in Embodiment 2, almost no current flows to adjacent array electrodes 20. Therefore, crosstalk is suppressed.

[0126] The above describes the pressure sensor 1H of modification example 7, and gives an example of changing the number of protrusions as a divided sensor layer with different sensitivities, but the present disclosure is not limited to this. For example, a first divided sensor layer and a second divided sensor having different hardnesses from each other may be used. Alternatively, a first divided sensor layer and a second divided sensor may be used that change the contact area from an insulating state to a conductive state by utilizing the magnitude of the pressure. In other words, as long as the pressures under which the divided sensor layers change from a mutually insulating state to a conductive state are different, there is no particular limitation on this method. In addition, the pressure sensor of the present disclosure may further include an opposite side sensor layer 70 (see FIG. 1 ) covering the entire membrane of the common electrode 50 relative to the pressure sensor 1H of modification example 7. Figure 18 Next, a pressure sensor 1I according to a third embodiment in which the opposing sensor layer 70 is deformed will be described.

[0127] (Implementation 3)

[0128] Figure 21 This is a plan view of the array substrate of the pressure sensor according to Embodiment 3 as viewed from the common electrode. Figure 22 yes Figure 21 The sectional view in the direction of arrow XXII-XXII. Figure 21 As shown, the opposing sensor layer 70I of the pressure sensor 1I of the third embodiment includes a plurality of third divided sensor layers 71A and a plurality of fourth divided sensor layers 71B alternately arranged in the second direction Dy. Furthermore, the pressure sensor 1I of the third embodiment differs from the seventh embodiment in that the individual detection regions 4 are formed in a square shape and include four array electrodes 20.

[0129] The third and fourth divided sensor layers 71A and 71B are opposing divided sensor layers extending in the first direction Dx. The third and fourth divided sensor layers 71A and 71B are separated from each other in the second direction Dy. In other words, the third and fourth divided sensor layers 71A and 71B are isolated from each other. Therefore, a gap S2 is provided between the third and fourth divided sensor layers 71A and 71B. In other words, the third and fourth divided sensor layers 71A and 71B are insulated from each other.

[0130] like Figure 22 As shown, the third divided sensor layer 71A contacts two protrusions 42 of the first divided sensor layer 41A and one protrusion 42 of the second divided sensor layer 41B. Although not specifically shown in the figure, the fourth divided sensor layer 71B contacts two protrusions 42 of the first divided sensor layer 41A and one protrusion 42 of the second divided sensor layer 41B.

[0131] In addition, with respect to the rubber that serves as the base material of the conductive elastomer of the pressure sensor 1I, the third divided sensor layer 71A is harder and more difficult to deform. In other words, the third divided sensor layer 71A is deformed and changes from an insulating state to a conductive state only when a pressure greater than a specified value is applied. On the other hand, the fourth divided sensor layer 71B is deformed and changes from an insulating state to a conductive state even when a pressure less than a specified value is applied. Therefore, the sensitivity of the third divided sensor layer 71A and the fourth divided sensor layer 71B is different. In addition, in the present embodiment, the sensitivity of the third divided sensor layer 71A and the fourth divided sensor layer 71B is different from that of the first divided sensor layer 41A and the second divided sensor layer 41B.

[0132] Hereinafter, the array electrode 20 overlapping the third divided sensor layer 71A and the second divided sensor layer 41B is referred to as the first array electrode 20A. The array electrode 20 overlapping the fourth divided sensor layer 71B and the second divided sensor layer 41B is referred to as the second array electrode 20B. The array electrode 20 overlapping the third divided sensor layer 71A and the first divided sensor layer 41A is referred to as the third array electrode 20C. The array electrode 20 overlapping the fourth divided sensor layer 71B and the first divided sensor layer 41A is referred to as the fourth array electrode 20D.

[0133] Next, a method of using the pressure sensor 1 according to Embodiment 3 will be described. The size of the input to the individual detection region 4 is divided into four stages, increasing in order of the first stage, the second stage, the third stage, and the fourth stage.

[0134] According to the pressure sensor 1I of the third embodiment, when the pressure input to the individual detection region 4 is at the first stage (very low pressure), for example, the third segmented sensor layer 71A and the second segmented sensor layer 41B deform and become conductive. This allows current to flow from the common electrode 50 to the first array electrode 20A.

[0135] When the pressure input to the individual detection region 4 reaches the second stage (slightly increased), for example, the fourth segmented sensor layer 71B and the second segmented sensor layer 41B deform and become conductive. Consequently, current flows from the common electrode 50 to the first array electrode 20A and the second array electrode 20B.

[0136] When the pressure input to the individual detection region 4 reaches the third stage (when it becomes even greater), for example, the third segmented sensor layer 71A and the first segmented sensor layer 41A deform and become conductive. This causes current to flow from the common electrode 50 to the first array electrode 20A, the second array electrode 20B, and the third array electrode 20C.

[0137] When the pressure input to the individual detection region 4 reaches the fourth stage (when the pressure increases further), for example, the fourth segmented sensor layer 71B and the first segmented sensor layer 41A deform and become conductive. Consequently, current flows from the common electrode 50 to the first array electrode 20A, the second array electrode 20B, the third array electrode 20C, and the fourth array electrode 20D.

[0138] The pressure sensor 1I of Embodiment 3 has four levels of sensitivity for detecting pressure. In other words, the range of detectable pressure (dynamic range) is expanded. Therefore, by selecting multiple gate lines 11 and multiple signal lines 12, the magnitude of the detected pressure can be set. Furthermore, in Embodiment 3, similar to Embodiment 2, almost no current flows between adjacent array electrodes 20, thereby suppressing crosstalk.

Claims

1. A pressure sensor comprising: An array substrate having a plurality of array electrodes provided on a first surface; an opposing substrate having an opposing surface opposing the first surface; a guard electrode disposed on the first surface and extending between the array electrodes; a sensor layer composed of a conductive elastic body and overlapping the first surface, the array electrode, and the guard electrode; as well as a common electrode provided on the opposing surface, The array substrate and the protection electrode are at the same potential.

2. The pressure sensor according to claim 1, wherein The sensor layer is a full-surface film that covers the first surface, the array electrode, and the guard electrode in their entirety.

3. The pressure sensor according to claim 2, wherein: The plurality of array electrodes are arranged in a first direction parallel to the first surface and in a second direction parallel to the first surface and intersecting the first direction. The protective electrode comprises: a plurality of first guard electrodes extending along the first direction between the array electrodes adjacent to each other in the second direction; and a plurality of second guard electrodes extending along the second direction between the array electrodes adjacent to each other in the first direction; The array electrode is arranged inside a rectangular frame formed by the first guard electrode and the second guard electrode.

4. The pressure sensor according to claim 2, wherein: The protective electrode comprises a plurality of ring-shaped protective electrodes, The array electrode is arranged inside the annular guard electrode.

5. The pressure sensor according to claim 3, wherein: The protective electrode comprises a plurality of ring-shaped protective electrodes, The array electrode is arranged inside the annular guard electrode. The pressure sensor according to claim 4 , wherein: A plurality of the annular guard electrodes are provided around one array electrode.

7. The pressure sensor according to claim 5, wherein: A plurality of the annular guard electrodes are provided around one array electrode.

8. The pressure sensor according to claim 1, wherein The plurality of array electrodes are arranged in a first direction parallel to the first surface and in a second direction parallel to the first surface and intersecting the first direction. The sensor layer is divided into a plurality of parts in the first direction, and each of the sensor layers has a divided sensor layer extending in the second direction. The guard electrode includes a plurality of crossing guard electrodes extending along the first direction and crossing the divided sensor layer when viewed from the common electrode.

9. The pressure sensor according to claim 8, wherein: The divided sensor layer includes first divided sensor layers and second divided sensor layers alternately arranged in the first direction. The first divided sensor layer and the second divided sensor layer have different pressures when changing from an insulating state to a conductive state.

10. The pressure sensor according to any one of claims 1 to 9, wherein: The counter substrate is provided with a counter-side sensor layer, which is made of a conductive elastic body and is a full-surface film covering the counter surface and the entire common electrode.

11. The pressure sensor according to claim 9, wherein The opposing substrate is provided with an opposing side sensor layer, the opposing side sensor layer being made of a conductive elastic body and covering the opposing surface and the entire common electrode. The opposing-side sensor layer is divided into a plurality of layers in the second direction, and each of the opposing-side sensor layers includes an opposing-side divided sensor layer extending in the first direction. The opposing divided sensor layer includes a third divided sensor layer and a fourth divided sensor layer alternately arranged in the second direction. The first divided sensor layer, the second divided sensor layer, the third divided sensor layer, and the fourth divided sensor layer have different pressures when changing from an insulating state to a conductive state.

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