Surface detection sensor and surface inspection device

Abstract

A surface detection sensor (1) for detecting a protrusion (3a) present on a surface of an object (3) comprises: a sheet-shaped elastic member (10); a sheet-shaped covering member (20) located on the object (3) side during the use of the surface detection sensor (1); a plurality of electrodes (30) disposed between the elastic member (10) and the covering member (20); at least one detection line (41) located between the plurality of electrodes (30) and the covering member (20) and disposed to intersect the plurality of electrodes (30); and an insulating layer (42) located between each of the plurality of electrodes (30) and the detection line (41).

Description

Surface Detection Sensor and Surface Inspection Device

[0001] The present disclosure relates to a surface detection sensor that detects protrusions present on the surface of an object and a surface inspection device including the surface detection sensor.

[0002] Conventionally, a technique for non-contact inspection of the surface state of an object by using a non-contact sensor such as an optical sensor has been known (for example, Patent Document 1). For example, when inspecting the surface state of an object with an optical sensor, laser light is irradiated onto the surface of the object, and the reflected light reflected from the surface of the object is received and analyzed.

[0003] Japanese Patent Application Laid-Open No. 2000-9453

[0004] However, when trying to inspect protrusions such as foreign substances present on the surface of an object (inspection target object) using an optical sensor, the laser light emitted from the optical sensor is diffusely reflected on the surface of the object due to the surface material of the object (such as porous or micro uneven shape), and it may not be possible to correctly detect the protrusions present on the surface of the object.

[0005] In addition, it is also conceivable to inspect protrusions present on the surface of an object non-contact using an imaging camera instead of an optical sensor. In this case, the imaging light (such as ambient light) is diffusely reflected on the surface of the object or the contrast is affected by the shadow of the protrusion. Therefore, it may not be possible to correctly detect the protrusions present on the surface of the object even when using an imaging camera. In particular, when the surface of the object is curved or has a complex surface shape, the influence of light diffuse reflection and the shadow of the protrusion becomes large, and it becomes difficult to detect the protrusions present on the surface of the object with an imaging camera.

[0006] The present disclosure has been made to solve such problems, and an object thereof is to provide a surface detection sensor and a surface inspection device that can easily detect protrusions on the surface of an object.

[0007] To achieve the above objective, one embodiment of the surface detection sensor according to the present disclosure is a surface detection sensor for detecting protrusions present on the surface of an object, comprising: a sheet-like elastic member; a sheet-like covering member located on the object side when the surface detection sensor is in use; a plurality of electrodes disposed between the elastic member and the covering member; at least one detection line located between the plurality of electrodes and the covering member and arranged to intersect the plurality of electrodes; and an insulating layer located between each of the plurality of electrodes and the detection line.

[0008] Furthermore, one embodiment of the surface inspection apparatus according to this disclosure comprises the above-mentioned surface detection sensor, a fixing member for fixing the surface detection sensor, and a buffer member disposed between the surface detection sensor and the fixing member.

[0009] According to this disclosure, protrusions present on the surface of an object can be easily detected.

[0010] Figure 1 is a plan view of the surface detection sensor according to Embodiment 1, when the covering member is omitted, as seen from the covering member side. Figure 2 is a cross-sectional view of the surface detection sensor according to Embodiment 1 along the line II-II in Figure 1. Figure 3 is an enlarged cross-sectional view of the surface inspection device according to Embodiment 1. Figure 4 is a diagram illustrating a method for inspecting the surface of an object using the surface inspection device according to Embodiment 1. Figure 5 shows the surface inspection device overcoming a protrusion present on the surface of an object. Figure 6 is a plan view of the surface detection sensor according to Embodiment 2, when the covering member is omitted, as seen from the covering member side. Figure 7 is a cross-sectional view of the surface detection sensor according to Embodiment 2 along the line VII-VII in Figure 6. Figure 8 is an enlarged cross-sectional view of a modified surface inspection device.

[0011] The embodiments of this disclosure will be described below with reference to the drawings. The embodiments described below are all specific examples of this disclosure. Therefore, the numerical values, shapes, materials, components, arrangement and connection configurations of components, as well as the processes (steps) and their order, shown in the following embodiments are examples and are not intended to limit this disclosure. Accordingly, any components in the following embodiments that are not described in the independent claims representing the highest-level concepts of this disclosure will be described as optional components.

[0012] Note that each figure is a schematic diagram and not necessarily a strictly accurate representation. Therefore, the scale and other aspects may not necessarily match in each figure. Also, in each figure, substantially identical components are given the same reference numerals, and redundant explanations are omitted or simplified. In each figure, the X, Y, and Z axes represent the three axes of a three-dimensional Cartesian coordinate system. In this embodiment, the Z-axis direction is defined as the vertical direction, and the direction perpendicular to the Z-axis (parallel to the XY plane) is defined as the horizontal direction. The X and Y axes are mutually orthogonal, and both are also perpendicular to the Z-axis. Note that in this specification, the terms "up" and "down" do not necessarily refer to the upward direction (vertically upward) and the downward direction (vertically downward) in absolute spatial perception.

[0013] (Embodiment 1) First, the configuration of the surface detection sensor 1 according to Embodiment 1 will be described using Figures 1 and 2. Figure 1 is a plan view of the surface detection sensor 1 according to Embodiment 1, when the covering member 20 is omitted, as seen from the covering member 20 side. Figure 2 is a cross-sectional view of the surface detection sensor 1 according to Embodiment 1 along the line II-II in Figure 1.

[0014] The surface detection sensor 1 is a contact-type sensor that inspects the surface of an object (subject) by making contact with its surface. Specifically, the surface detection sensor 1 detects protrusions on the surface of an object by moving relative to the object in a predetermined direction, which is the first direction (the X-axis direction in this embodiment). The surface detection sensor 1 is a thin, sheet-like sensor.

[0015] As shown in Figures 1 and 2, the surface detection sensor 1 comprises an elastic member 10, a covering member 20, a plurality of electrodes 30, and a plurality of electric wires 40. As shown in Figure 2, the plurality of electrodes 30 and the plurality of electric wires 40 are arranged between the elastic member 10 and the covering member 20.

[0016] The elastic member 10 is a sheet-like sheet member. Specifically, the elastic member 10 is a flat sheet member with a constant thickness. The planar shape of the elastic member 10 is, for example, rectangular, but is not limited to this.

[0017] The elastic member 10 is an elastic body that has elasticity and is elastically deformable. Specifically, the elastic member 10 is a rubber body made of rubber material and has rubber elasticity. In this embodiment, the elastic member 10 is made of ethylene propylene diene rubber (EPDM). Alternatively, the elastic member 10 may be made of an elastomer. In this case, EPDM elastomer can be used as the material for the elastic member 10. However, the material for the elastic member 10 is not limited to EPDM. Furthermore, the elastic member 10 may have a laminated structure in which multiple elastic sheets are laminated together.

[0018] As shown in Figure 1, the elastic member 10 is provided over the entirety of the multiple electrodes 30. In other words, the elastic member 10 is arranged to cover the multiple electrodes 30. In this embodiment, the elastic member 10 covers all of the electrodes 30.

[0019] The covering member 20 is positioned opposite the elastic member 10. The covering member 20 is a sheet-like sheet member. Specifically, the covering member 20 is a flat sheet member with a uniform thickness. The plan view shape of the covering member 20 is, for example, rectangular, but is not limited to this.

[0020] The covering member 20 covers multiple electric wires 40. In this embodiment, the covering member 20 covers all of the electric wires 40. The covering member 20 also covers multiple electrodes 30 along with the electric wires 40. Although not shown in the figures, the covering member 20 is provided over the entire surface of the multiple electrodes 30, similar to the elastic member 10.

[0021] The covering member 20 is an outer casing member that constitutes the outer casing of the surface detection sensor 1. The covering member 20 comes into contact with the target object when the surface detection sensor 1 is in use. The covering member 20 may be made of a resin material or a metal material, but since the surface detection sensor 1 is slid with the covering member 20 in contact with the target object when the surface detection sensor 1 is in use, it is preferable to use a material for the covering member 20 that is slippery and resistant to scratches. The covering member 20 may be an elastic body that deforms elastically, a solid body that does not deform elastically, or a soft fibrous material such as cloth or nonwoven fabric.

[0022] As shown in Figure 2, the electrode 30 is positioned on the elastic member 10 side of the electric wire 40. In this embodiment, multiple electrodes 30 are arranged on the elastic member 10. Each of the multiple electrodes 30 is a pattern electrode formed in a predetermined pattern.

[0023] Multiple electrodes 30 are arranged in a predetermined layout. As shown in Figure 1, the multiple electrodes 30 are arranged along the X-axis and Y-axis directions, respectively. Specifically, the multiple electrodes 30 are arranged in a matrix. The multiple electrodes 30 are arranged separately without touching each other. Therefore, two adjacent electrodes 30 in the X-axis and Y-axis directions are arranged with a predetermined gap between them.

[0024] In this embodiment, the outer shape of each of the multiple electrodes 30 is a rectangle with the X-axis direction as its longitudinal direction. Therefore, the multiple electrodes 30 arranged in a matrix are rectangular as a whole. The multiple electrodes 30 may all have the same area, but the multiple electrodes 30 may include electrodes 30 with different areas.

[0025] In Figure 1, a total of eight electrodes 30 are arranged: two in the X-axis direction and four in the Y-axis direction. However, the number of electrodes 30 in the X-axis and Y-axis directions, and the total number of electrodes 30, are not limited to these. Also, in Figure 1, the multiple electrodes 30 are divided into left and right sides in the center, but this is not limited to this arrangement. For example, the multiple electrodes 30 may be divided into left and right sides at a point other than the center. Alternatively, the two left and right electrodes 30 may be connected as one. In this case, the multiple electrodes 30 would become four electrodes 30 arranged in a row.

[0026] Multiple electrodes 30, which are arranged separately from each other, are provided on the elastic member 10 and together with the elastic member 10 constitute an electrode block. In other words, the surface detection sensor 1 has multiple electrode blocks.

[0027] As shown in Figure 2, each of the multiple electrodes 30 is a laminated structure in which multiple conductive layers are stacked. In this embodiment, each electrode 30 has a two-layer structure and comprises a first conductive layer 31 and a second conductive layer 32 laminated on the first conductive layer 31. The first conductive layer 31 and the second conductive layer 32 are made of a conductive material such as a metal material.

[0028] The outer shape of the first conductive layer 31 corresponds to the outer shape of the electrode 30. Therefore, in this embodiment, the plan view shape of the first conductive layer 31 is rectangular. The first conductive layer 31 is, for example, a carbon layer (carbon electrode) made of carbon (C).

[0029] The second conductive layer 32 is located between the first conductive layer 31 and the elastic member 10. In other words, the second conductive layer 32 is laminated on the first conductive layer 31 on the elastic member 10 side of the first conductive layer 31. Specifically, the second conductive layer 32 is provided on the elastic member 10, and the first conductive layer 31 is provided on the elastic member 10 so as to cover the second conductive layer 32.

[0030] The second conductive layer 32 is laminated on a portion of the first conductive layer 31. In this embodiment, the second conductive layer 32 extends along the longitudinal direction (X-axis direction in this embodiment) of the first conductive layer 31 in the central part of the width direction of the first conductive layer 31. In other words, the second conductive layer 32 is narrower than the first conductive layer 31. For example, the second conductive layer 32 has a certain width and is formed in a straight line.

[0031] The resistivity of the second conductive layer 32 is lower than that of the first conductive layer 31. For example, if the first conductive layer 31 is made of carbon, the material of the second conductive layer 32 is silver (Ag). By laminating the second conductive layer 32, which has a lower resistivity than the first conductive layer 31, onto the first conductive layer 31, the overall resistivity of the electrode 30 can be reduced compared to the case where the electrode 30 is made only of the first conductive layer 31. In other words, the resistance of the electrode 30 can be reduced.

[0032] In this embodiment, the second conductive layer 32 was positioned on the elastic member 10 side of the first conductive layer 31, but this is not limited to this configuration. Specifically, the second conductive layer 32 may be positioned on the covering member 20 side (wire 40 side) of the first conductive layer 31. In this case, the first conductive layer 31 would be located between the elastic member 10 and the second conductive layer 32.

[0033] The electrodes 30 configured in this way are connected to a detection circuit 50. The detection circuit 50 is, for example, an IC (integrated circuit) and can be placed on the elastic member 10. The electrodes 30 and the detection circuit 50 are connected by lead wires 60. The lead wires 60 are drawn out from a plurality of electrodes 30. The lead wires 60 are connected to the second conductive layer 32 of each electrode 30. Specifically, the lead wires 60 and the second conductive layer 32 are formed integrally and simultaneously. In this embodiment, since the second conductive layer 32 is made of silver, the lead wires 60 are also made of silver. In this case, for example, the lead wires 60 and the second conductive layer 32 can be formed integrally by applying silver paste to the elastic member 10 and hardening it. The surface detection sensor 1 may also have a separate circuit board for mounting the detection circuit 50.

[0034] As shown in Figure 1, in a plan view, the electric wire 40 is arranged to intersect with multiple electrodes 30. In this embodiment, the electric wire 40 extends in the Y-axis direction and intersects with multiple electrodes 30 aligned in the Y-axis direction in three dimensions.

[0035] Furthermore, the electric wire 40 is connected to the detection circuit 50. Specifically, the electric wire 40 is drawn out from the detection circuit 50, crosses all the electrodes 30 arranged in the Y-axis direction, is folded back in a U-shape beyond the final electrode 30, crosses all the same electrodes 30 again, and is routed back to the detection circuit 50. In other words, two electric wires 40 cross each electrode 30 by being folded back. Thus, one end of the electric wire 40 and the other end are connected to the detection circuit 50, and the electric wire 40 is routed in a loop shape. Note that the electric wire 40 may be folded back in a shape other than U. Also, the electric wire 40 does not have to be folded back beyond the final electrode 30. In other words, instead of one folded electric wire 40 crossing a single electrode 30, multiple unfolded, separate electric wires 40 may cross each other.

[0036] In this embodiment, there are multiple wires 40. Specifically, two wires 40 (four wires 40 in total, round trip) intersect one electrode 30. In other words, two detection cells correspond to one electrode 30, and in Figure 1, there are a total of 16 detection cells. Note that the number of wires 40 is not limited to multiple wires; it is sufficient that at least one wire 40 is arranged to intersect with multiple electrodes 30.

[0037] Furthermore, as shown in Figure 2, the electric wire 40 is located between the electrode 30 and the covering member 20. As described above, since the electric wire 40 intersects with multiple electrodes 30, the electric wire 40 is located between the multiple electrodes 30 and the covering member 20. In this embodiment, the electric wire 40 is sandwiched between the electrode 30 and the covering member 20 and is in contact with each of the electrodes 30 and the covering member 20. Specifically, the electric wire 40 is in contact with the first conductive layer 31 of the electrode 30.

[0038] The electric wire 40 is a wire (cable), and as shown in Figure 2, the cross-sectional shape of the electric wire 40 is circular. In other words, unlike the layered electrode 30, the electric wire 40 is not patterned in a predetermined shape.

[0039] As shown in Figure 2, the electric wire 40 has a detection wire 41 and an insulating layer 42. In this embodiment, the electric wire 40 is an insulated coated wire, and has a core wire made of a conductive material and an insulating film (insulating coating) covering this core wire. The detection wire 41 is the core wire of this insulated coated wire, and the insulating layer 42 is the insulating film of this insulated coated wire. As shown in Figure 2, in cross-section, the insulating layer 42 covers the detection wire 41 so as to surround its entire circumference. In this embodiment, the electric wire 40 is a copper wire. In this case, the detection wire 41, which is the core wire of the copper wire, is made of copper. The insulating layer 42, which is the insulating film of the copper wire, is made of a dielectric material that has insulating properties. For example, the insulating layer 42 is a resin coating made of an insulating resin material.

[0040] As described above, the electric wire 40 is arranged to intersect with the multiple electrodes 30. Therefore, the detection wire 41 and the insulating layer 42 are also arranged to intersect with the multiple electrodes 30. Furthermore, as described above, the electric wire 40 is located between the multiple electrodes 30 and the covering member 20. Therefore, the detection wire 41 and the insulating layer 42 are also located between the multiple electrodes 30 and the covering member 20.

[0041] Furthermore, the insulating layer 42 is located between at least each of the electrodes 30 and the detection line 41. In other words, the insulating layer 42 is present between the electrodes 30 and the detection line 41, and the electrodes 30 and the detection line 41 are arranged with a predetermined distance between them. Therefore, the electrodes 30 and the detection line 41 facing each other constitute a capacitor, with one being the first opposing electrode and the other the second opposing electrode.

[0042] Note that, in the present embodiment, the insulating layer 42 covers the entire circumference of the detection line 41 (core wire) as an insulating film. Therefore, the insulating layer 42 not only exists between the electrode 30 and the detection line 41, but also exists between the covering member 20 and the detection line 41. Therefore, when the covering member 20 is made of a conductive material such as a metal material, a capacitor is also formed by the covering member 20 and the detection line 41.

[0043] In the surface detection sensor 1 configured as described above, a detection unit that detects the convex portions present on the surface of the object is formed by each of the plurality of electrodes 30 and the detection line 41 that intersects the plurality of electrodes 30. In the present embodiment, the electrode 30 and the detection line 41 form a capacitor as a detection unit, and the surface detection sensor 1 detects the convex portions present on the surface of the object based on the change in the capacitance (capacitance value) generated between the electrode 30 and the detection line 41. Specifically, since the electrode 30 and the detection line 41 are electrically connected to the detection circuit 50, when the capacitance generated between the electrode 30 and the detection line 41 changes, the detection circuit 50 detects the change in the capacitance. Thereby, the detection circuit 50 can detect that there are convex portions on the surface of the object.

[0044] In the present embodiment, the electrodes 30 are arranged in a plurality, separated from each other. Therefore, a plurality of capacitors are formed by each of the plurality of electrodes 30 and the detection line 41 facing this electrode 30, and the region where the plurality of electrodes 30 exist becomes a detection region for detecting the convex portions on the surface of the object.

[0045] As shown in FIG. 3, the surface detection sensor 1 in the present embodiment can be used in a surface inspection device 2 for inspecting the surface of an object. FIG. 3 is an enlarged cross-sectional view of the surface inspection device 2 according to Embodiment 1.

[0046] As shown in FIG. 3, in the surface inspection apparatus 2, the surface detection sensor 1 is fixed to a fixing member 110 for fixing the surface detection sensor 1. In the present embodiment, the surface inspection apparatus 2 includes the surface detection sensor 1, the fixing member 110, and a buffer member 120 disposed between the surface detection sensor 1 and the fixing member 110. That is, the surface detection sensor 1 is fixed to the fixing member 110 via the buffer member 120.

[0047] Next, a method of inspecting the surface of an object using the surface inspection apparatus 2 will be described with reference to FIGS. 4 and 5. FIG. 4 is a diagram for explaining a method of inspecting the surface of an object 3 using the surface inspection apparatus 2 according to the first embodiment. FIG. 5 is a diagram showing a state when the surface inspection apparatus 2 gets over a convex portion 3a existing on the surface of the object 3.

[0048] As shown in FIG. 4, the surface inspection apparatus 2 can detect a convex portion 3a existing on the surface of the object 3 as a defective portion. Specifically, the convex portion 3a existing on the surface of the object 3 can be detected by the surface detection sensor 1. The convex portion 3a existing on the surface of the object 3 is, for example, a foreign matter attached to the surface of the object 3 or a protrusion formed as a part of the object 3.

[0049] When inspecting the surface of the object 3 by the surface inspection apparatus 2, as shown in (a) of FIG. 4, the surface inspection apparatus 2 is arranged such that the surface detection sensor 1 faces the object 3. Specifically, the surface inspection apparatus 2 is arranged such that the covering member 20 of the surface detection sensor 1 faces the object 3. Thus, the covering member 20 will be located on the object 3 side when the surface detection sensor 1 is in use.

[0050] Then, as shown in Figure 4(b), the surface inspection device 2 (surface detection sensor 1) is moved vertically and placed on the object 3 so that the coating member 20 contacts the object 3. After that, as shown in Figure 4(b), the surface inspection device 2 (surface detection sensor 1) is moved horizontally. In other words, the surface inspection device 2 (surface detection sensor 1) is moved so that it slides along the surface of the object 3 while the coating member 20 remains in contact with the object 3. At this time, the surface detection sensor 1 slides along the surface of the object 3. Note that in Figure 4(b), the surface inspection device 2 (surface detection sensor 1) is moved in the X-axis direction.

[0051] At this time, as shown in Figure 4(b), if a protrusion 3a exists on the surface of object 3 at the destination of the surface inspection device 2, the surface detection sensor 1 will slide over the protrusion 3a of object 3. When the surface detection sensor 1 overcomes the protrusion 3a, as shown in Figure 5(a), the covering member 20 of the surface detection sensor 1 deforms so as to be pushed inward by the protrusion 3a.

[0052] Then, as shown in Figure 5(b), when the surface inspection device 2 slides further and the protrusion 3a is positioned below the wire 40 of the surface detection sensor 1, and the wire 40 and the protrusion 3a face each other, the wire 40 is pushed inward together with the covering member 20, and the position of the wire 40 is displaced. In other words, the wire 40 is displaced by the pressure from the protrusion 3a via the covering member 20. Specifically, the wire 40 moves upward (in the Z-axis direction). Consequently, the detection wire 41 and the insulating layer 42 that constitute the wire 40 move upward.

[0053] As the electric wire 40 moves upward in this manner, the electric wire 40 pushes up the electrode 30 and the elastic member 10, causing the electrode 30 and the elastic member 10 to deform so that they become convex upwards. Specifically, the elastic member 10 undergoes elastic deformation, and the electrode 30 provided on the elastic member 10 also deforms in accordance with the deformation of the elastic member 10.

[0054] At this time, the electrode 30 and the detection wire 41 form a capacitor, so as the electrode 30 and the wire 40 move upward, the capacitance (capacitance value) between the electrode 30 and the detection wire 41 changes. By detecting this change in capacitance with the detection circuit 50, it is possible to detect the presence of a protrusion 3a on the surface of object 3.

[0055] Then, when the surface inspection device 2 slides further and the protrusion 3a is no longer below the surface inspection device 2, the elastically deformed elastic member 10 returns to its original state due to its elastic restoring force. As a result, the electric wire 40 and the electrode 30 return to their original positions.

[0056] In this embodiment, the surface inspection device 2 (surface detection sensor 1) is moved in the X-axis direction. In this case, the multiple electrodes 30, which are arranged separately from each other, should be aligned at least in the Y-axis direction (direction perpendicular to the direction of movement). In this embodiment, the multiple electrodes 30 are aligned not only in the Y-axis direction (direction perpendicular to the direction of movement) but also in the X-axis direction (direction of movement).

[0057] As described above, the surface detection sensor 1 according to this embodiment comprises an elastic member 10, a covering member 20 located on the object 3 side when the surface detection sensor 1 is in use, a plurality of electrodes 30 disposed between the elastic member 10 and the covering member 20, at least one detection line 41 located between the plurality of electrodes 30 and the covering member 20 and arranged to intersect with the plurality of electrodes 30, and an insulating layer 42 located between each of the plurality of electrodes 30 and the detection line 41.

[0058] In this configuration, the surface detection sensor 1 is brought into contact with the surface of the object 3 such that the covering member 20 is positioned on the object 3 side. When a protrusion 3a (foreign matter, etc.) is present on the surface of the object 3, the detection line 41 is pushed inward and displaced by the protrusion 3a via the covering member 20. In other words, the detection line 41 is displaced by the pressure from the protrusion 3a. By detecting the displacement of the detection line 41, it is possible to detect the presence of a protrusion 3a on the surface of the object 3. Thus, the surface detection sensor 1 according to this embodiment can easily detect a protrusion 3a present on the surface of the object 3.

[0059] In particular, since the surface detection sensor 1 according to this embodiment is a contact-type sensor that brings the covering member 20 into contact with the surface of the object 3, it can easily detect protrusions 3a present on the surface of the object 3 even if the surface of the object 3 is curved or has a complex surface shape.

[0060] Furthermore, in the surface detection sensor 1 according to this embodiment, a capacitor is formed by each of the multiple electrodes 30 and the detection line 41, and the protrusions 3a present on the surface of the object 3 are detected based on the change in capacitance that occurs between the multiple electrodes 30 and the detection line 41. This makes it possible to easily detect the protrusions 3a present on the surface of the object 3. Thus, the surface detection sensor 1 according to this embodiment is a capacitive pressure sensor. In addition, the surface detection sensor 1 according to this embodiment is also a pressure sensor (pressure-sensitive sensor) that detects the presence of protrusions 3a by receiving pressure from the protrusions 3a.

[0061] Furthermore, the surface inspection device 2 according to this embodiment includes a surface detection sensor 1, a fixing member 110 for fixing the surface detection sensor 1, and a buffer member 120 disposed between the surface detection sensor 1 and the fixing member 110.

[0062] As a result, even if the elastic member 10 is significantly deformed by the pressure of the electric wire 40 on the surface of object 3 by the protrusion 3a, the deformation can be absorbed by the cushioning member 120.

[0063] Although not shown in the figures, the surface detection sensor 1 or surface inspection device 2 may further include at least one of the following sensors: an acceleration sensor, an angle sensor, and an angular velocity sensor. This allows for the collection of surface condition information of the object 3 or sensor operation information in response to changes in the shape of the object 3 when the surface of the object 3 is not planar. These sensors can be mounted, for example, on the elastic member 10 on which the detection circuit 50 is mounted or on the circuit board.

[0064] (Embodiment 2) Next, the surface detection sensor 1A according to Embodiment 2 will be described with reference to Figures 6 and 7. Figure 6 is a plan view of the surface detection sensor 1A according to Embodiment 2, when the covering member 20 is omitted, as seen from the covering member 20 side. Figure 7 is a cross-sectional view of the surface detection sensor 1A according to Embodiment 2 along the line VII-VII in Figure 6.

[0065] As shown in Figures 6 and 7, the surface detection sensor 1A in this embodiment differs from the surface detection sensor 1 in the first embodiment in the plan view shape of the electrode 30A. Specifically, as shown in Figure 6, in the surface detection sensor 1A in this embodiment, each of the multiple electrodes 30A has a first inclined portion 311 and a second inclined portion 312.

[0066] The first inclined portion 311 and the second inclined portion 312 are inclined with respect to the X-axis direction, which is the direction of movement of the surface detection sensor 1A, in a plan view, but their inclination directions are different. Furthermore, the first inclined portion 311 and the second inclined portion 312 are formed continuously, and each of the first inclined portion 311 and the second inclined portion 312 is formed in a straight line. Specifically, the plan view shape of the electrode 30A, which is composed of the first inclined portion 311 and the second inclined portion 312, is V-shaped. In other words, the electrode 30A is formed to bend, and there are concave and convex portions on the opposing sides of the bent portion of the electrode 30A.

[0067] In this embodiment, the first inclined portion 311 and the second inclined portion 312 are symmetrical. Therefore, in a plan view, the area of ​​the first inclined portion 311 and the area of ​​the second inclined portion 312 are the same.

[0068] Furthermore, the multiple V-shaped electrodes 30A are arranged in close proximity to each other in the Y-axis direction. Specifically, two adjacent electrodes 30A in the Y-axis direction are formed such that the convex portion of the bent portion of one electrode 30A fits into the concave portion of the bent portion of the other electrode 30A.

[0069] In this embodiment, the first inclined portion 311 and the second inclined portion 312 are the first conductive layer 31A of the electrode 30A. That is, the first inclined portion 311 is a part of the first conductive layer 31A, and the second inclined portion 312 is the remaining part of the first conductive layer 31A. Therefore, the first conductive layer 31A is formed in a V-shape. In addition, the second conductive layer 32A of the electrode 30A is also formed in a V-shape following the shape of the first conductive layer 31A.

[0070] Except for the planar shape of the electrode 30A, the surface detection sensor 1A according to this embodiment is the same as the surface detection sensor 1 according to Embodiment 1 described above.

[0071] The surface detection sensor 1A configured in this way can be used in a surface inspection device for inspecting the surface of an object, similar to the first embodiment described above. Also, similar to the first embodiment, the surface of an object can be inspected by using a surface inspection device equipped with the surface detection sensor 1A. In other words, the surface detection sensor 1A can detect protrusions present on the surface of an object. Specifically, similar to the first embodiment, when the surface detection sensor 1A is brought into contact with an object and slid along it, the change in capacitance that occurs between the electrode 30A and the detection wire 41 due to the pressing of the electric wire 40 can be detected, thereby detecting the presence of protrusions on the surface of the object.

[0072] As described above, the surface detection sensor 1A according to this embodiment also comprises an elastic member 10, a covering member 20 located on the object side when the surface detection sensor 1A is in use, a plurality of electrodes 30A disposed between the elastic member 10 and the covering member 20, at least one detection line 41 located between the plurality of electrodes 30A and the covering member 20 and arranged to intersect with the plurality of electrodes 30A, and an insulating layer 42 located between each of the plurality of electrodes 30A and the detection line 41.

[0073] With this configuration, as with Embodiment 1 described above, protrusions on the surface of an object can be easily detected.

[0074] Furthermore, in the surface detection sensor 1A according to this embodiment, each of the multiple electrodes 30A has a first inclined portion 311 that is inclined with respect to the X-axis direction, which is the direction of movement of the surface detection sensor 1A.

[0075] This configuration allows for reliable detection of protrusions on the surface of an object, compared to Embodiment 1 described above. This point will be explained below.

[0076] In the surface detection sensor 1 of the above embodiment 1, each electrode 30 extends linearly parallel to the X-axis direction. Therefore, the region between two adjacent electrodes 30 in the Y-axis direction (i.e., the region where no electrodes 30 exist) also exists linearly along the X-axis direction. Consequently, when the surface detection sensor 1 is moved in the X-axis direction to inspect a protrusion on the surface of an object, if the protrusion is located in the region between two adjacent electrodes 30 in the Y-axis direction, even if the surface detection sensor 1 is slid along the X-axis direction, the protrusion will not come to a position opposite the electrode 30, and therefore cannot be detected. In other words, with the shape of the electrodes 30 of the surface detection sensor 1 of the above embodiment 1, there are protrusions that cannot be detected. That is, there are cases where protrusions cannot be detected.

[0077] In contrast, in the surface detection sensor 1A according to this embodiment, each of the multiple electrodes 30A has a first inclined portion 311 that is inclined with respect to the direction in which the surface detection sensor 1A is moved when inspecting protrusions on the surface of an object (in this embodiment, the X-axis direction). With this configuration, the region between two adjacent electrodes 30A in a direction perpendicular to the direction of movement of the surface detection sensor 1A (in this embodiment, the Y-axis direction) (i.e., the region where no electrodes 30A exist) is inclined with respect to the direction of movement of the surface detection sensor 1A (in this embodiment, the X-axis direction). As a result, when the surface detection sensor 1A is moved in the X-axis direction when inspecting protrusions on the surface of an object, the protrusions on the surface of the object will always face one of the multiple electrodes 30A. In other words, in a top view, the protrusions on the surface of the object will always pass through one of the multiple electrodes 30A. Therefore, protrusions on the surface of an object can be reliably detected.

[0078] Furthermore, in the surface detection sensor 1A according to this embodiment, the electrode 30A has not only the first inclined portion 311, but also a second inclined portion 312 that is formed continuously with the first inclined portion 311 and has a different inclination direction from the first inclined portion 311. Specifically, the electrode 30A is bent in a V-shape.

[0079] This configuration allows multiple electrodes 30A to be efficiently arranged even if the electrodes 30A are bent, thus reducing the dead space around the multiple electrodes 30A compared to the case where the electrodes 30A are composed only of the first inclined portion 311. Therefore, a compact surface detection sensor 1A can be realized even with bent electrodes 30A.

[0080] In this embodiment, the first inclined portion 311 and the second inclined portion 312 of the electrode 30A were straight lines, but this is not limited to them. For example, the first inclined portion 311 and the second inclined portion 312 may be arc-shaped. In this case, the planar shape of the electrode 30A may be wave-shaped, as an example.

[0081] (Modifications) The surface detection sensors 1, 1A and the surface inspection device 2 according to the present disclosure have been described above based on embodiments 1 and 2, but the present disclosure is not limited to embodiments 1 and 2.

[0082] For example, the cushioning member 120 of the surface inspection device 2 in the above embodiments 1 and 2 was made of a single material, but is not limited to this. Specifically, as shown in the surface inspection device 2A in Figure 8, the cushioning member 120A may be a laminated structure of a first cushioning body 121 and a second cushioning body 122. In Figure 8, the first cushioning body 121 is located on the surface detection sensor 1 side, and the second cushioning body 122 is located on the fixing member 110 side. In this case, it is preferable that the first cushioning body 121 and the second cushioning body 122 have different hardnesses. Specifically, it is preferable that the Young's modulus of the first cushioning body 121 and the Young's modulus of the second cushioning body 122 are different. This allows the cushioning member 120A to effectively absorb the changes in the elastic member 10 caused by the pressing of the electric wire 40. In this case, it is preferable that the Young's modulus of the first cushioning body 121, which is located on the surface detection sensor 1 side (elastic member 10 side), be greater than the Young's modulus of the second cushioning body 122. This allows the cushioning member 120A to more effectively absorb the changes in the elastic member 10 caused by the compression of the electric wire 40.

[0083] Furthermore, in embodiments 1 and 2 described above, the protrusions 3a on the surface of object 3 were detected by moving the surface inspection device 2 (surface detection sensors 1 and 1A) without moving object 3, but this is not limited to this. For example, the protrusions 3a on the surface of object 3 may be detected by moving object 3 without moving the surface inspection device 2 (surface detection sensors 1 and 1A), or the protrusions 3a on the surface of object 3 may be detected by moving both the surface inspection device 2 (surface detection sensors 1 and 1A) and object 3 relative to each other. In other words, the protrusions 3a on the surface of object 3 can be detected by moving the surface inspection device 2 (surface detection sensors 1 and 1A) relative to object 3.

[0084] Furthermore, in the embodiments 1 and 2 described above, the electrode 30 (30A) was composed of a first conductive layer 31 (31A) and a second conductive layer 32 (32A), but it is not limited to this. For example, the electrode 30 (30A) may be composed of only the first conductive layer 31 (31A).

[0085] Furthermore, in the above embodiments 1 and 2, the second conductive layer 32 (32A) was formed separately for each of the multiple first conductive layers 31 (31A), but this is not limited to this. For example, the second conductive layer 32 (32A) may be formed continuously across a plurality of first conductive layers 31. For example, in Figure 1, the second conductive layer 32 may be formed along the X-axis so as to straddle two first conductive layers 31 aligned in the X-axis direction. In other words, in Figure 1, two second conductive layers 32 aligned in the X-axis direction may be connected.

[0086] Furthermore, in embodiments 1 and 2 described above, the region between two adjacent electric wires 40 between the elastic member 10 and the covering member 20 was an air layer (space), but this is not limited to this. For example, if the electric wires 40 are displaced by the protrusion 3a of the object 3, the space between two adjacent electric wires 40 may be filled with a filler material or the like.

[0087] Furthermore, this disclosure also includes forms obtained by applying various modifications to the above embodiments that a person skilled in the art could conceive, and forms realized by arbitrarily combining the components and functions of the embodiments without departing from the spirit of this disclosure. In addition, this disclosure also includes any combination of two or more claims from the multiple claims described in the claims of this application, provided that they are not technically contradictory. For example, if the cited claims described in the claims of this application are made into a multi-claim or multi-multi-claim so as to refer to all of the higher-level claims without technically contradictory, then all combinations of claims included in that multi-claim or multi-multi-claim are also included in this disclosure.

[0088] The technology disclosed herein is useful as a surface detection sensor and surface inspection device, etc., used when inspecting the surface of an object.

[0089] 1, 1A Surface detection sensor 2, 2A Surface inspection device 3 Object 3a Protrusion 10 Elastic member 20 Covering member 30, 30A Electrode 31, 31A First conductive layer 32, 32A Second conductive layer 40 Electric wire 41 Detection wire 42 Insulating layer 50 Detection circuit 60 Outlet wiring 110 Fixing member 120, 120A Buffer member 121 First buffer 122 Second buffer 311 First inclined part 312 Second inclined part

Claims

1. A surface detection sensor for detecting protrusions on the surface of an object, comprising: a sheet-like elastic member; a sheet-like covering member positioned on the object side when the surface detection sensor is in use; a plurality of electrodes disposed between the elastic member and the covering member; at least one detection line located between the plurality of electrodes and the covering member and arranged to intersect with the plurality of electrodes; and an insulating layer located between each of the plurality of electrodes and the detection line.

2. The surface detection sensor detects protrusions on the surface of an object by moving relative to the object in a first direction, and the plurality of electrodes are arranged in at least a second direction perpendicular to the first direction, according to claim 1.

3. The surface detection sensor according to claim 2, wherein the plurality of electrodes are also arranged in the first direction.

4. The surface detection sensor according to claim 3, wherein, in a plan view, each of the plurality of electrodes has a first inclined portion that is inclined with respect to the first direction.

5. In a plan view, each of the plurality of electrodes further has a second inclined portion that is inclined with respect to the first direction and in a direction different from the inclination direction of the first inclined portion, and the second inclined portion is formed in continuity with the first inclined portion, the surface detection sensor according to claim 4.

6. The surface detection sensor according to claim 5, wherein the first inclined portion and the second inclined portion extend in a straight line or an arc shape.

7. A surface detection sensor according to any one of claims 1 to 6, comprising an insulated coated wire having a core wire made of a conductive material and an insulating film covering the core wire, wherein the detection wire is the core wire and the insulating layer is the insulating film.

8. A surface detection sensor according to any one of claims 1 to 6, which detects a protrusion present on the surface of an object based on a change in capacitance occurring between the plurality of electrodes and the detection line.

9. The surface detection sensor according to any one of claims 1 to 6, wherein the elastic member is provided over the entirety of the plurality of electrodes.

10. Each of the plurality of electrodes has a first conductive layer and a second conductive layer laminated on a part of the first conductive layer, the second conductive layer is located between the first conductive layer and the elastic member, and the resistivity of the second conductive layer is lower than the resistivity of the first conductive layer, the surface detection sensor according to any one of claims 1 to 6.

11. The surface detection sensor according to any one of claims 1 to 6, further comprising at least one of an acceleration sensor, an angle sensor, and an angular velocity sensor.

12. A surface inspection device comprising: a surface detection sensor according to any one of claims 1 to 6; a fixing member for fixing the surface detection sensor; and a buffer member disposed between the surface detection sensor and the fixing member.

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