Detection device

Abstract

The present invention provides a detection device with an expanded pressure sensitivity range while avoiding a decrease in sensitivity. [Solution] The detection device comprises an array substrate and a sensor layer facing the array substrate. The array substrate has a first surface facing the sensor layer and a plurality of detection electrodes provided on the first surface. The detection electrodes comprise a first detection unit and a second detection unit positioned closer to the sensor layer than the first detection unit.

Description

【Technical Field】 【0001】 The present invention relates to a detection device. 【Background Art】 【0002】 A detection device is a device that detects a load (pressure) acting perpendicular to a detection surface. The detection device has a common electrode, a detection electrode, and a sensor layer in contact with each of the common electrode and the detection electrode. The sensor layer in the following patent document has, for example, a main body portion formed of rubber and a plurality of conductive particles dispersed inside the main body portion. When pressure is applied to the sensor layer, the main body portion collapses and the conductive particles come into contact with each other. As a result, the resistance value of the sensor layer decreases, and current flows from the common electrode to the detection electrode through the sensor layer. 【Prior Art Documents】 【Patent Documents】 【0003】 【Patent Document 1】 Japanese Patent Application Laid-Open No. 2018-146489 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0004】 By the way, it is desired to expand the range of pressure values that can be detected by the detection device (hereinafter referred to as the pressure-sensitive range). On the other hand, when the resistance value of the sensor layer is increased, the pressure-sensitive range is expanded, but the output value output from the detection electrode becomes small, leading to a decrease in sensitivity. Therefore, it is desired to develop a detection device that can expand the pressure-sensitive range while avoiding a decrease in sensitivity. 【0005】 An object of the present invention is to provide a detection device with an expanded pressure-sensitive range while avoiding a decrease in sensitivity. 【Means for Solving the Problems】 【0006】 A detection device according to one aspect of the present disclosure includes an array substrate and a sensor layer facing the array substrate. The array substrate has a first surface facing the sensor layer and a plurality of detection electrodes provided on the first surface. The detection electrodes include a first detection unit and a second detection unit positioned closer to the sensor layer than the first detection unit. [Brief explanation of the drawing] 【0007】 [Figure 1] Figure 1 is a schematic diagram of the detection device according to Embodiment 1, viewed from the front. [Figure 2] Figure 2 is a schematic diagram of a cross-section of the detection device of Embodiment 1, and more specifically, it is a schematic cross-sectional view of the cross-section taken along line II-II in Figure 3. [Figure 3] Figure 3 is an enlarged view of a portion of the first surface (one individual detection area) of the array substrate of Embodiment 1, as seen from the sensor layer side. [Figure 4] Figure 4 is a magnified view of the area around the first contact hole and the detection electrode in Figure 2. [Figure 5] Figure 5 is a circuit diagram showing the circuit configuration of the detection device of Embodiment 1. [Figure 6] Figure 6 is a schematic cross-sectional view showing the state in which pressure is input to the detection device of Embodiment 1. [Figure 7] Figure 7 is a schematic cross-sectional view showing the condition when a greater pressure is applied than in Figure 6. [Figure 8] Figure 8 is a schematic cross-sectional view showing the condition when a greater pressure is applied than in Figure 7. [Figure 9] Figure 9 is a schematic cross-sectional view showing the condition when a greater pressure is applied than in Figure 8. [Figure 10] Figure 10 is a cross-sectional view of the detection device of Comparative Example 1, cut in the stacking direction. [Figure 11] Figure 11 is a graph showing the relationship between the pressure applied to the detection surface and the amount of current flowing through the detection electrode in the detection devices of Embodiment 1, Comparative Example 1, and Comparative Example 2. [Figure 12]Figure 12 is a cross-sectional view of the detection device of Modified Example 1, cut in the stacking direction. [Figure 13] Figure 13 is a cross-sectional view of the detection device of modified example 2, cut in the stacking direction, and more specifically, it is a cross-sectional view taken along the line XIII-XIII in Figure 14. [Figure 14] Figure 14 is an enlarged view of a portion of the first surface (one individual detection area) of the array substrate of Modified Example 2, viewed from the sensor layer side. [Figure 15] Figure 15 is a cross-sectional view of the detection device of Modified Example 3, cut in the stacking direction, and more specifically, it is a cross-sectional view taken along the line XV-XV in Figure 16. [Figure 16] Figure 16 is an enlarged view of a portion of the first surface (one individual detection area) of the array substrate of Modified Example 3, viewed from the sensor layer side. [Figure 17] Figure 17 is a cross-sectional view of the detection device of modified example 4, cut in the stacking direction, and more specifically, a cross-sectional view taken along the line XVII-XVII in Figure 17. [Figure 18] Figure 18 is an enlarged view of a portion of the first surface (one individual detection area) of the array substrate of Modified Example 4, viewed from the sensor layer side. [Modes for carrying out the invention] 【0008】 Embodiments for implementing the detection device of this disclosure will be described in detail with reference to the drawings. The invention of this disclosure is not limited by the contents described in the following embodiments. Furthermore, the components described below include those that can be easily conceived by a person skilled in the art, and those that are substantially the same. Moreover, the components described below can be combined as appropriate. It should be noted that the disclosure is merely an example, and any modifications that can be easily conceived by a person skilled in the art while maintaining the spirit of the invention are naturally included within the scope of the present invention. In order to make the explanation clearer, 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 the present invention. Furthermore, in this specification and each drawing, components that are the same as those described above with respect to previously shown drawings are denoted by the same reference numerals, and detailed explanations may be omitted as appropriate. 【0009】 Also, in this specification and the claims, when expressing the mode of arranging one structure on another structure, if it is simply stated as "on", unless otherwise specified, it includes both the case of arranging another structure directly above so as to be in contact with one structure and the case of arranging another structure above one structure through yet another structure. 【0010】 (Embodiment 1) FIG. 1 is a schematic view of the detection device according to Embodiment 1 seen from the front. The detection device 100 is a device that detects the pressure acting on the detection surface 1. As shown in FIG. 1, the detection device 100 is formed in a flat plate shape. The detection device 100 has a planar front surface (detection surface 1) and a planar back surface 2 (not shown in FIG. 1; see FIG. 2). The detection device 100 is rectangular when viewed from the normal direction of the detection surface 1. Since the detection device 100 shown in FIG. 1 has a planar detection surface 1, the pressure distribution within the detection surface 1 can be detected. 【0011】 The detection surface 1 is divided into a detection region 3 capable of detecting pressure and a peripheral region 4 incapable of detecting pressure. The detection region 3 is located at the central portion of the detection surface 1. The peripheral region 4 is formed in a frame shape and surrounds the outside of the detection region 3. 【0012】 The detection region 3 is formed in a rectangular shape when viewed from the normal direction of the detection surface 1. Therefore, the outer frame M of the detection region 3 has a pair of short sides 3a and a pair of long sides 3b. Hereinafter, the direction parallel to the detection surface 1 and parallel to the short side 3a is referred to as the first direction X. The direction parallel to the detection surface 1 and parallel to the long side 3b is referred to as the second direction Y. Therefore, the second direction Y is a direction orthogonal (intersecting) to the first direction X. Also, in the following, the direction parallel to the detection surface 1 may be referred to as the planar direction. 【0013】 The detection area 3 is divided into a plurality of individual detection areas 5. In other words, the detection area 3 is a collection of a plurality of individual detection areas 5. And the pressure value is detected in each of the individual detection areas 5. When viewed from the normal direction of the detection surface 1, the individual detection area 5 is square-shaped. The plurality of individual detection areas 5 are arranged in the first direction X and the second direction Y. 【0014】 FIG. 2 is a diagram schematically showing a cross-section of the detection device according to Embodiment 1, and more specifically, is a cross-sectional view schematically showing a cross-section cut along line II-II of FIG. 3. As shown in FIG. 2, the detection device 100 includes an array substrate 10, a sensor layer 70, and a protective layer 80 stacked in this order. Hereinafter, the direction in which the array substrate 10, the sensor layer 70, and the protective layer 80 are stacked is referred to as the stacking direction. Note that the normal direction of the detection surface 1 described above has the same meaning as the stacking direction. Also, among the stacking directions, the direction in which the sensor layer 70 is arranged when viewed from the array substrate 10 is referred to as the first stacking direction Z1, and the opposite direction is referred to as the second stacking direction Z2. Viewing from the first stacking direction Z1 is referred to as a plan view. 【0015】 The array substrate 10 includes a base material 11 and an array layer 12 formed on the surface of the base material 11 in the first stacking direction Z1. The base material 11 is a plate-shaped member that supports the array layer 12 and has insulating properties. Examples of the base material 11 include a flexible substrate formed of polyimide, but the present disclosure is not limited thereto. Also, the surface of the base material 11 in the second stacking direction Z2 constitutes the back surface 2 of the detection device 100. 【0016】 The array layer 12 has a first insulating layer 13, a second insulating layer 14, and a third insulating layer 15 stacked in this order on the surface of the base material 11 in the first stacking direction Z1. Note that a gate insulating film 42 of a transistor 40 described later is provided between the first insulating layer 13 and the second insulating layer 14. 【0017】 The first insulating layer 13, the second insulating layer 14, and the third insulating layer 15 are formed of an insulating material. The insulating material may be either an inorganic or organic material. The third insulating layer 15 is a layer (planarization film) for planarizing the first surface 16 of the array layer 12 in the first stacking direction Z1. Although the array layer 12 in this embodiment has three insulating layers, this disclosure does not particularly limit the number of insulating layers. 【0018】 The first surface 16 of the array layer 12 has a detection electrode 20, a common electrode 30, a first contact hole 6, and a second contact hole 7 formed thereon. 【0019】 Figure 3 is an enlarged view of a portion of the first surface (one individual detection area) of the array substrate of Embodiment 1, viewed from the sensor layer side. In Figure 3, dots are added to the detection electrode 20 and the common electrode 30 to make them easier to see. The detection electrode 20 and the common electrode 30 are metal films (metal layers) deposited on the first surface 16 using a metallic material such as ITO (Indium Tin Oxide). 【0020】 As shown in Figure 3, one detection electrode 20 is placed for each individual detection region 5. In other words, multiple detection electrodes 20 are formed on the first surface 16. The detection electrodes 20 are located in the center of each individual detection region 5. When viewed from above, the outer shape of the detection electrode 20 is square. 【0021】 As shown in Figure 3, one common electrode 30 is placed for each individual detection region 5. In other words, multiple common electrodes 30 are formed on the first surface 16. The common electrode 30 is formed in the shape of a rectangular frame in plan view. The detection electrode 20 is placed inside the common electrode 30, and the common electrode 30 surrounds the detection electrode 20. Furthermore, the common electrode 30 and the detection electrode 20 are separated in the planar direction on the first surface 16 and are not connected. 【0022】 As shown in Figure 2, the first contact hole 6 and the second contact hole 7 are holes extending from the first surface 16 of the array substrate 10 in the second stacking direction Z2. A connection wiring 49, which will be described later, is located in the second stacking direction Z2 of the first contact hole 6. A reference potential wiring 48, which will be described later, is located in the second stacking direction Z2 of the second contact hole 7. One first contact hole 6 and one second contact hole 7 are formed for each individual detection region 5. 【0023】 As shown in Figure 3, the first contact hole 6 is located in the center of the individual detection area 5. The second contact hole 7 is located on the first surface 16 in a portion that overlaps with the common electrode 30. As a result, as shown in Figure 2, a portion of the detection electrode 20 is located within the first contact hole 6, forming a first contact portion 29 that connects to the connection wiring 49. In addition, a portion of the common electrode 30 is located within the second contact hole 7, forming a second contact portion 39 that connects to the reference potential wiring 48. 【0024】 As shown in Figure 2, the cross-sectional shape of the inner surface of the first contact hole 6, cut in the stacking direction, is stepped. Therefore, the detection electrode 20 stacked on the inner surface of the first contact hole 6 also has a stepped cross-sectional shape. The details are explained below. 【0025】 Figure 4 is an enlarged view of the vicinity of the first contact hole and the detection electrode in Figure 2. As shown in Figure 4, the inner surface of the first contact hole 6 has two horizontal surfaces 60 extending in the planar direction and three vertical surfaces 61 extending in the stacking direction. The two horizontal surfaces 60 are the first horizontal surface 62 and the second horizontal surface 63, arranged in order from the second stacking direction Z2. The three vertical surfaces 61 are the first vertical surface 64, the second vertical surface 65, and the third vertical surface 66, arranged in order from the second stacking direction Z2. The first vertical surface 64 extends from the first horizontal surface 62 in the second stacking direction Z2. The second vertical surface 65 connects the first horizontal surface 62 and the second horizontal surface 63. The third vertical surface 66 connects the second horizontal surface 63 and the first surface 16. 【0026】 The detection electrode 20 has a first contact portion 29, three planar portions 21 extending in the planar direction, and three vertical wall portions 22 extending in the stacking direction. The three planar portions 21 are a first planar portion 23 stacked on the first lateral surface 62, a second planar portion 24 stacked on the second lateral surface 63, and a third planar portion 25 stacked on the first surface 16. In this specification, the first planar portion 23 may be referred to as the first detection portion, and the second planar portion 24 may be referred to as the second detection portion. 【0027】 The three vertical wall sections 22 are a first vertical wall section 26 extending along the first vertical surface 64, a second vertical wall section 27 extending along the second vertical surface 65, and a third vertical wall section 28 extending along the third vertical surface 66. The first vertical wall section 26 connects the first contact section 29 and the first planar section 23. The second vertical wall section 27 connects the first planar section 23 and the second planar section 24. The third vertical wall section 28 connects the second planar section 24 and the third planar section 25. 【0028】 As shown in Figure 3, the first planar portion 23, the second planar portion 24, the third planar portion 25, the first vertical wall portion 26, the second vertical wall portion 27, and the third vertical wall portion 28 are each rectangular (annular) in plan view. In other words, the first lateral surface 62, the second lateral surface 63, the first vertical wall portion 26, the second vertical wall portion 27, and the third vertical wall portion 28 of the first contact hole 6 are also rectangular (annular) in plan view. From the above, the detection electrode 20 is positioned in the second stacking direction Z2 as it moves towards the center. 【0029】 Figure 5 is a circuit diagram showing the circuit configuration of the detection device of Embodiment 1. As shown in Figure 5, the array layer 12 contains a transistor 40, a gate line 46, a signal line 47, a reference potential wiring 48, a connection part 50 (see Figure 1), a gate line drive circuit 51 (see Figure 1), a signal line selection circuit 52 (see Figure 1), and a common wiring 53 (see Figure 1). In addition, multiple transistors 40, gate lines 46, signal lines 47, and reference potential wiring 48 are formed in the array layer 12 (array substrate 10). 【0030】 Transistor 40 is a switching element. Multiple transistors 40 are arranged one at a time for each individual detection region 5. As shown in Figure 2, transistor 40 comprises a semiconductor layer 41, a gate insulating film 42, a gate electrode 43, a drain electrode 44, and a source electrode 45. The end of the source electrode 45 in the first stacking direction Z1 is connected to a connecting wire 49. The connecting wire 49 extends in the planar direction (see Figure 3) and is connected to the first contact portion 29. Therefore, the source electrode 45 is connected to the detection electrode 20 via the connecting wire 49 and the first contact portion 29. 【0031】 As shown in Figure 5, the gate line 46 extends in the first direction X. Multiple gate lines 46 are arranged in the second direction Y. As shown in Figure 4, the gate line 46 is provided with a branch portion 46a that extends in the second direction Y. The branch portion 46a is provided in each individual detection region 5. The gate line 46 is connected to each gate electrode 43 (see Figure 2) of the multiple transistors 40 arranged in the first direction X via the branch portion 46a. 【0032】 As shown in Figure 5, the signal line 47 extends in the second direction Y. Multiple signal lines 47 are arranged in the first direction X. The signal line 47 is connected to the drain electrodes 44 (see Figure 2) of multiple transistors 40 arranged in the second direction Y. 【0033】 As shown in Figure 5, the reference potential wiring 48 extends in the second direction Y. Multiple reference potential wirings 48 are arranged in the first direction X. As shown in Figure 2, the reference potential wiring 48 is connected to the second contact portion 39 of the common electrode 30. 【0034】 As shown in Figure 1, the connection section 50, gate line drive circuit 51, signal line selection circuit 52, and common wiring 53 are located in the peripheral region 4 of the array layer 12. The connection section 50 is for connecting to a drive IC (Integrated Circuit) located outside the detection device 100. The drive IC may be mounted as COF (Chip On Film) on a flexible printed circuit board or rigid board connected to the connection section 50. Alternatively, the drive IC may be mounted as COG (Chip On Glass) in the peripheral region 4 of the array substrate 10. 【0035】 The gate line drive circuit 51 is a circuit that drives multiple gate lines 46 (see Figure 5) based on various control signals from the drive IC. The gate line drive circuit 51 sequentially or simultaneously selects multiple gate lines 46 and supplies gate drive signals to the selected gate lines 46. 【0036】 The signal line selection circuit 52 is a switch circuit that sequentially or simultaneously selects multiple signal lines 47 (see Figure 5). The signal line selection circuit 52 is, for example, a multiplexer. Based on the selection signal supplied from the drive IC, the signal line selection circuit 52 connects the selected signal line 47 to the drive IC. Since the detection region is equipped with a transistor 40, a gate line 46, signal lines 47, and a reference potential wiring 48, the detection device 100 can measure the change in the pressure distribution in the plane over time. 【0037】 The common wiring 53 is connected to the drive IC via the connection part 50, and a constant amount of current is supplied from the drive IC. The common wiring 53 extends along the surrounding region and is ring-shaped. The reference potential wiring 48 is connected to the common wiring 53. As a result, a constant amount of current is supplied to the common electrode 30. 【0038】 As shown in Figure 2, the sensor layer 70 comprises a deformable insulating body portion 71 made of silicone rubber or the like, and conductive fine particles 72 dispersed inside the body portion 71. When no pressure is applied to the sensor layer 70, it has a high resistance. On the other hand, when pressure is applied to the sensor layer 70 and the body portion 71 deforms, the conductive fine particles 72 come into contact with or near the sensor layer 70, and the resistance of the sensor layer 70 decreases. In addition, the surface 73 of the sensor layer 70 in the second stacking direction Z2 is in contact with the third planar portion 25 and the common electrode 30 of the detection electrode. 【0039】 The protective layer 80 is made of an elastically deformable and insulating material, such as rubber or resin. The surface of the protective layer 80 in the first lamination direction serves as the detection surface 1. In addition, the integrated sensor layer 70 and protective layer 80 are bonded to the array substrate 10 via a frame-shaped frame portion (not shown) in the area overlapping with the peripheral region 4. 【0040】 Next, the operation of the detection device 100 will be explained. As shown in Figure 2, when no pressure is applied to the detection surface 1, the resistance of the sensor layer 70 is high. Therefore, no current flows from the common electrode 30 to the sensor layer 70. 【0041】 On the other hand, when pressure is applied to the detection surface 1, a compressive load in the stacking direction acts on the sensor layer 70, and the resistance of the sensor layer 70 decreases. As a result, current flows from the common electrode 30 to the detection electrode 20 through the sensor layer 70 (see arrow A1 in Figure 6). Furthermore, as the pressure applied to the detection surface 1 increases, the decrease in the resistance of the sensor layer 70 increases. In other words, the amount of current flowing from the common electrode 30 to the detection electrode 20 increases. Thus, the amount of current flowing to the detection electrode 20 is proportional to the magnitude of the applied pressure. 【0042】 The electrical signal (current value) input to the detection electrode 20 is then output to the drive IC via the signal line 47. The drive IC determines the load input to the individual detection area 5 based on the magnitude of the current value. 【0043】 Furthermore, the amount of current flowing from the common electrode 30 to the detection electrode 20 via the sensor layer 70 changes not only due to increases or decreases in the resistance value of the sensor layer 70 itself, but also due to increases or decreases in the contact area between the sensor layer 70 and the detection electrode 20. Specifically, when the contact area between the sensor layer 70 and the detection electrode 20 increases, the amount of current flowing to the detection electrode 20 increases. In this embodiment, the contact area between the sensor layer 70 and the detection electrode 20 changes as follows in response to increases or decreases in pressure. 【0044】 Figure 6 is a schematic cross-sectional view showing the detection device of Embodiment 1 when pressure is input. Figure 7 is a schematic cross-sectional view showing the state when a greater pressure than that in Figure 6 is input. Figure 8 is a schematic cross-sectional view showing the state when a greater pressure than that in Figure 7 is input. Figure 9 is a schematic cross-sectional view showing the state when a greater pressure than that in Figure 8 is input. 【0045】 As shown in Figure 6, when the pressure F1 applied to the detection surface 1 is relatively small, the sensor layer 70 contacts only the third planar portion 25 of the detection electrode 20. When the pressure F2 applied to the detection surface 1 is greater than the pressure F1 (F2 > F1), as shown in Figure 7, the sensor layer 70 moves in the second stacking direction Z2 and contacts the second planar portion 24. In other words, the sensor layer 70 contacts both the third planar portion 25 and the second planar portion 24 of the detection electrode 20, increasing the contact area. Therefore, the amount of current flowing through the detection electrode 20 (see arrow A2 in Figure 7) is greater than when pressure F1 is applied (see arrow A1 in Figure 6). 【0046】 As shown in Figure 8, when a pressure F3 greater than pressure F2 is applied to the detection surface 1 (F3 > F2), the sensor layer 70 moves further in the second stacking direction Z2 and comes into contact with the first planar portion 23. In other words, the sensor layer 70 comes into contact with the third planar portion 25, the second planar portion 24, and the first planar portion 23 of the detection electrode 20, increasing the contact area. As a result, the amount of current flowing through the detection electrode 20 (see arrow A3 in Figure 8) is greater than when pressure F2 is applied (see arrow A2 in Figure 7). 【0047】 As shown in Figure 9, when a pressure F4 greater than pressure F3 is input to the detection surface 1 (F4 > F3), the sensor layer 70 moves further in the second stacking direction Z2 and comes into contact with the first contact portion 29. In other words, the sensor layer 70 comes into contact with the third planar portion 25, the second planar portion 24, the first planar portion 23, and the first contact portion 29, increasing the contact area. As a result, the amount of current flowing through the detection electrode 20 (see arrow A4 in Figure 9) is greater than when pressure F3 is input (see arrow A3 in Figure 8). 【0048】 From the above, in this embodiment, as the pressure increases, the contact area between the sensor layer 70 and the detection electrode 20 increases, and the amount of current flowing to the detection electrode 20 also increases. 【0049】 Figure 10 is a cross-sectional view of the detection device of Comparative Example 1, cut in the stacking direction. Figure 11 is a graph showing the relationship between the pressure input to the detection surface and the amount of current flowing through the detection electrode in the detection devices of Embodiment 1, Comparative Example 1, and Comparative Example 2. Next, the effects of the detection device 100 of Embodiment 1 will be explained. First, the detection devices of Comparative Example 1 and Comparative Example 2 will be explained. 【0050】 As shown in Figure 10, the detection device 1000 of Comparative Example 1 differs from Embodiment 1 in that the detection electrode 1020 extends along the first surface 1016 of the array substrate 1010. In other words, in the detection device 1000 of Comparative Example 1, the contact area between the detection electrode 1020 and the sensor layer 1070 does not change even if the pressure applied to the detection surface increases. Also, the resistivity of the sensor layer 1070 is the same as the resistivity of the sensor layer 70 of Embodiment 1. 【0051】 Although not specifically shown in the figures, the detection device of Comparative Example 2 has the same structure as that of Comparative Example 1. However, the resistivity of the sensor layer of the detection device of Comparative Example 2 is higher than that of the sensor layer 1070 of Comparative Example 1 and the sensor layer 70 of Embodiment 1. 【0052】 As shown in Figure 11, in the detection device 1000 of Comparative Example 1, the resistance of the sensor layer 1070 decreases in proportion to the magnitude of the input pressure. Therefore, the amount of current flowing through the detection electrode 1020 increases. Also, in Comparative Example 1, the contact area between the sensor layer 1070 and the detection electrode 1020 does not increase or decrease even if the magnitude of the input pressure increases or decreases. In other words, because the contact area between the sensor layer 1070 and the detection electrode 1020 is large, the amount of current flowing through the detection electrode 1020 increases even at small pressures. Furthermore, in the detection device 100 of Comparative Example 1, the maximum output value C1 (the maximum amount of current flowing through the detection electrode 1020) occurs when the input pressure is B1. Therefore, the pressure sensitivity range (the range in which pressure can be detected) of the detection device 1000 is from a pressure value of 0 (zero) to B1. 【0053】 On the other hand, in the detection device of Comparative Example 2, the resistivity of the sensor layer is high, so even when pressure B1 is input, the output value (amount of current flowing through the detection electrode) does not reach its maximum. Therefore, the detection device of Comparative Example 2 can detect pressures greater than pressure B1. Also, the detection device of Comparative Example 2 reaches its maximum output value (maximum amount of current flowing through the detection electrode) when the pressure value B2 is greater than pressure B1. Therefore, the pressure sensitivity range of the detection device of Comparative Example 2 is from pressure 0 (zero) to B2. However, because the resistivity of the sensor layer of the detection device of Comparative Example 2 is high, the output value is small. In other words, the maximum output value C2 of the detection device of Comparative Example 2 is smaller than the maximum output value C1 of the detection device 1000 of Comparative Example 1, indicating reduced sensitivity. 【0054】 On the other hand, according to the detection device 100 of Embodiment 1, the contact area between the sensor layer 70 and the detection electrode 20 does not increase unless the pressure input to the detection surface 1 increases. In other words, the amount of current flowing through the detection electrode 20 is kept small. For this reason, even when pressure B1 is input, the amount of current flowing through the detection electrode 20 of the detection device 100 of Embodiment 1 is smaller than that of Comparative Example 1. Therefore, the pressure sensitivity range of the detection device 100 of Embodiment 1 is from pressure 0 (zero) to B2, which is a larger pressure sensitivity range than that of Comparative Example 1. Also, the resistivity of the sensor layer 70 of Embodiment 1 is the same as that of the sensor layer 1070 of Comparative Example 1. Therefore, the maximum output value (maximum amount of current flowing through the detection electrode 20) is C1, the same as in Comparative Example 1. In other words, Embodiment 1 avoids the decrease in sensitivity seen in Comparative Example 2. 【0055】 Based on the above, the detection device 100 of Embodiment 1 avoids a decrease in sensitivity and expands the pressure sensitivity range. 【0056】 The first embodiment has been described above. Next, a modified example in which a part of the detection electrode of the first embodiment has been modified will be described. Furthermore, the following description will focus on the differences from the first embodiment. 【0057】 (Variation 1) Figure 12 is a cross-sectional view of the detection device of Modified Example 1, cut in the stacking direction. As shown in Figure 12, the detection electrode 20A of the detection device 100A of Modified Example 1 differs from Embodiment 1 in that it does not have a third planar portion 25 and a third vertical wall portion 28. As a result, the sensor layer 70 and the detection electrode 20A are not in contact when no pressure is input. Therefore, noise is less likely to be input to the detection electrode 20. In addition, the electrode consumption of the detection device 100A can be reduced. 【0058】 Next, we will describe a modified example in which not only the detection electrode but also the shape of the first surface has been changed. 【0059】 (Modification 2) Figure 13 is a cross-sectional view of the detection device of Modified Example 2, cut in the stacking direction, and more specifically, a cross-sectional view taken along the line XIII-XIII in Figure 14. Figure 14 is an enlarged view of a part of the first surface (one individual detection area) of the array substrate of Modified Example 2, viewed from the sensor layer side. As shown in Figure 13, the first contact hole 6 on the first surface 16 of the array substrate 10 differs from Embodiment 1 in that it extends linearly in the stacking direction. Therefore, the inner surface of the first contact hole 6 consists of only one vertical surface 61 extending in the stacking direction. Furthermore, the first surface 16 of the array substrate 10 differs from Embodiment 1 in that a hemispherical protrusion 90 is formed on it that projects in the first stacking direction Z1. The cross-section of the protrusion 90, cut in the stacking direction, is semicircular. 【0060】 The detection electrode 120 is stacked on the first surface 16, the first contact hole 6, and the protrusion 90. Therefore, the portion of the detection electrode 120 stacked on the first surface 16 is a planar portion 121 extending in the planar direction. The portion of the detection electrode 120 stacked on the first contact hole 6 constitutes a vertical wall portion 124 and a first contact portion 129. The portion of the detection electrode 120 stacked on the protrusion 90 is a hemispherical projection 122. The cross-sectional shape of the projection 122 cut in the stacking direction is a semicircle. The part of the projection 122 that is furthest in the first stacking direction Z1 is the apex portion 123. 【0061】 As shown in Figure 14, there are four protrusions 122 (convex portions 90). The four protrusions 122 (convex portions 90) are arranged to be four-fold rotationally symmetric (four-fold symmetry) around the first contact hole 6. The tops 123 of the protrusions 122 are in contact with the sensor layer 70. In this specification, the flat portion 121 may be referred to as the first detection portion. Also, the tops 123 of the protrusions 122 may be referred to as the second detection portion. 【0062】 As described above, according to Modification 2, when the pressure is low, the sensor layer 70 contacts only the top portion 123 of the protrusion. When the pressure increases, the sensor layer 70 contacts the portion of the protrusion 122 that is in the second stacking direction Z2 rather than the top portion 123. Furthermore, when the pressure applied to the detection surface increases, the sensor layer 70 contacts the flat portion 121. 【0063】 From the above, according to the detection device 100B of modified example 2, the contact area between the sensor layer 70 and the detection electrode 120 does not increase unless the pressure input to the detection surface 1 increases. Therefore, the amount of current flowing through the detection electrode 120 can be kept low, and the pressure sensitivity range can be expanded. Furthermore, a decrease in sensitivity is avoided. 【0064】 (Variation 3) Figure 15 is a cross-sectional view of the detection device of Modified Example 3, cut in the stacking direction, and more specifically, a cross-sectional view taken along the line XV-XV in Figure 16. Figure 16 is an enlarged view of a part of the first surface (one individual detection area) of the array substrate of Modified Example 3, viewed from the sensor layer side. As shown in Figure 15, Modified Example 3 differs from Modified Example 2 in that the array substrate 10 of the detection device 100C has recesses 91 instead of protrusions 90. The recesses 91 are hemispherical depressions, and the cross-section cut in the stacking direction is semicircular. 【0065】 The detection electrode 120C is laminated on the first surface 16, the first contact hole 6, and the recess 91. Therefore, the portion of the detection electrode 120C laminated on the first surface 16 is a planar portion 121 that extends in the planar direction. The portion of the detection electrode 120C laminated on the first contact hole 6 constitutes a vertical wall portion 124 and a first contact portion 129. The portion of the detection electrode 120C laminated on the recess 91 has a semicircular projection 125 when cut in the lamination direction. The projection 125 protrudes from the planar portion 121 in the second lamination direction Z2, in other words, in the direction opposite to the direction in which the sensor layer 70 is arranged. The part of the projection 125 that is furthest in the second lamination direction Z2 is the top portion 126. 【0066】 As shown in Figure 16, there are four protrusions 125 (recesses 91). The four protrusions 125 (recesses 91) and the flat portion 121 are in contact with the sensor layer 70. In this specification, the top portion 126 of the protrusion 125 may be referred to as the first detection portion. Also, the flat portion 121 may be referred to as the second detection portion. 【0067】 As described above, according to Modification 3, when the pressure is low, the sensor layer 70 contacts only the flat portion 121. When the pressure increases, the sensor layer 70 contacts the protrusion 125 (excluding the top portion 126). When the pressure increases further, the sensor layer 70 contacts the top portion 126 of the protrusion 125. 【0068】 From the above, according to the detection device 100C of modified example 3, the contact area between the sensor layer 70 and the detection electrode 120C does not increase unless the pressure input to the detection surface 1 increases. As a result, the amount of current flowing through the detection electrode 120C can be kept low, and the pressure sensitivity range can be expanded. Furthermore, a decrease in sensitivity is avoided. 【0069】 (Modification 4) Figure 17 is a cross-sectional view of the detection device of Modified Example 4, cut in the stacking direction, and more specifically, a cross-sectional view taken along the line XVII-XVII in Figure 17. Figure 18 is an enlarged view of a part of the first surface (one individual detection area) of the array substrate of Modified Example 4, viewed from the sensor layer side. As shown in Figure 17, the detection device 100D of Modified Example 4 differs from Embodiment 1 in that a first convex portion 92 and a second convex portion 93 are formed that protrude from the first surface 16 in the first stacking direction Z1. Also, the first contact hole 6 on the first surface 16 of the array substrate 10 differs from Embodiment 1 in that it extends linearly in the stacking direction. 【0070】 The first protrusion 92 and the second protrusion 93 have a rectangular cross-sectional shape. The first protrusion 92 has a first convex surface 92a that faces the first stacking direction Z1 and is parallel to the planar direction. The second protrusion 93 has a second convex surface 93a that faces the first stacking direction Z1 and is parallel to the planar direction. 【0071】 As shown in Figure 18, the first protrusion 92 and the second protrusion 93 are rectangular (annular) in plan view. The first protrusion 92 is located on the inner circumference side of the second protrusion 93. Therefore, a part of the first surface 16 (hereinafter referred to as the first side wall 16a) is located between the first contact hole 6 and the first protrusion 92. A part of the first surface 16 (hereinafter referred to as the second side wall 16b) is also located between the first protrusion 92 and the second protrusion 93. The first side wall 16a and the second side wall 16b are rectangular (annular) in plan view. 【0072】 The detection electrode 120D is stacked on the first contact hole 6, the first lateral wall portion 16a, the first protrusion 92, the second lateral wall portion 16b, and the second protrusion 93. The portion of the detection electrode 120D stacked on the first lateral wall portion 16a is a first planar portion 131 that extends in the planar direction. The portion of the detection electrode 120D stacked on the first convex surface 92a is a second planar portion 132 that extends in the planar direction. The portion of the detection electrode 120D stacked on the second lateral wall portion 16b is a third planar portion 133 that extends in the planar direction. The portion of the detection electrode 120D stacked on the second convex surface 93a is a fourth planar portion 134 that extends in the planar direction. 【0073】 As shown in Figure 18, the first planar portion 131, the second planar portion 132, the third planar portion 133, and the fourth planar portion 134 form a rectangular frame (ring) with the center of the detection electrode 120D when viewed from the stacking direction. In plan view, the second planar portion 132 is positioned between the first planar portion 131 and the third planar portion 133. The third planar portion 133 is positioned between the second planar portion 132 and the fourth planar portion 134. As shown in Figure 17, the first planar portion 131 and the third planar portion 133 are in the same position in the stacking direction. The second planar portion 132 and the fourth planar portion 134 are positioned further in the first stacking direction Z1 than the first planar portion 131 and the third planar portion 133. The second planar portion 132 and the fourth planar portion 134 are in contact with the sensor layer 70. 【0074】 As described above, according to Modification 4, when the pressure applied to the detection surface 1 is small, the sensor layer 70 contacts only the second planar portion 132 and the fourth planar portion 134. When the pressure applied to the detection surface 1 increases, the sensor layer 70 also contacts the first planar portion 131 and the third planar portion 133. 【0075】 From the above, according to the detection device 100D of modified example 4, the contact area between the sensor layer 70 and the detection electrode 120D does not increase unless the pressure input to the detection surface 1 increases. As a result, the amount of current flowing through the detection electrode 120D can be kept low, and the pressure sensitivity range can be expanded. Furthermore, a decrease in sensitivity is avoided. [Explanation of Symbols] 【0076】 1 Detection surface 3. Detection area 4. Peripheral area 5 Individual detection area 10 Array substrates 11 Base material 12 array layers 16 Front page 20, 20A, 120D detection electrodes 21 Plane section 22 Vertical wall section 23 1st plane part 24 Second plane part 25 3rd plane part 26 1st vertical wall section 27 Second vertical wall section 28 Third vertical wall section 29, 129 First Contact Section 30 common electrode 60 Side view 61 Vertical surface 70 Sensor Layers 80 protective layer 90 Convex part 91 Recess 92 First protrusion 93 Second protrusion 100, 100A, 100B, 100C, 100D detection devices 121 Plane section 122 Protrusion 123, 126 top 125 Protrusion 131 First Plane Section 132 Second Plane Section 133 Third Plane Section 134 Fourth Plane

Claims

[Claim 1] Array substrate and The sensor layer facing the array substrate, It has, The aforementioned array substrate is The first surface facing the sensor layer, Multiple detection electrodes provided on the first surface, It has, The aforementioned detection electrode is First detection unit, A second detection unit is positioned closer to the sensor layer than the first detection unit, It has Detection device. [Claim 2] The direction in which the array substrate and the sensor layer are arranged is defined as the stacking direction. The aforementioned detection electrode is A plurality of planar portions extending in a planar direction parallel to the first surface, The vertical wall portion extending in the stacking direction, It has, The plurality of planar portions include a first planar portion and a second planar portion whose positions in the stacking direction are different from each other. The vertical wall portion connects the first planar portion and the second planar portion, The cross-section of the detection electrode cut in the stacking direction is stepped, The first detection unit is the first planar portion, The second detection unit is the second planar portion. The detection device according to claim 1. [Claim 3] The first planar portion, the second planar portion, and the vertical wall portion are annular in shape when viewed from the stacking direction, with the central part of the detection electrode at the center. The detection device according to claim 2. [Claim 4] The direction in which the array substrate and the sensor layer are arranged is defined as the stacking direction. The aforementioned detection electrode is A planar portion extending in a plane direction parallel to the first surface, A plurality of protrusions projecting from the planar portion in the stacking direction, It has, The aforementioned protruding portion has a semicircular cross-section when cut in the stacking direction. The first detection unit is the planar portion, The second detection unit is the top of the protruding portion. The detection device according to claim 1. [Claim 5] The aforementioned protrusion is projecting toward the sensor layer. The detection device according to claim 4. [Claim 6] The aforementioned protrusions protrude in the direction opposite to the direction in which the sensor layer is positioned. The detection device according to claim 4. [Claim 7] The direction in which the array substrate and the sensor layer are arranged is defined as the stacking direction. The detection electrode has a plurality of planar portions extending in a planar direction parallel to the first surface, Multiple of the aforementioned planar portions include: The first planar section and The first planar portion and the second planar portion are located in a position different from the position in the stacking direction, The first planar portion and the third planar portion are in the same position in the stacking direction, Includes, The second planar portion is positioned between the first planar portion and the second planar portion. The first detection unit is the first planar portion, The second detection unit is the second planar portion. The detection device according to claim 1. [Claim 8] The first, second, and third planar portions are annular in shape when viewed from the stacking direction, with the central part of the detection electrode at the center. The detection device according to claim 7.

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