JP2017069170A - Holding detection device and sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sensor having a wide detection range by a simple circuit configuration.SOLUTION: A sensor 20A comprises: a lower substrate 22 that can be attached to a rim 12; an upper substrate 26 arranged above the lower substrate 22; and an electrode pair 80 configured by a lower electrode 50 attached to an upper surface of the lower substrate 22, and an upper electrode 60 attached to a lower surface of the upper substrate 26 so as to be opposed to the lower electrode 50; and a substrate spacer 24 arranged around the electrode pair 80. The upper electrode 60 and the lower electrode 50 are configured by pressure sensing electrodes. The substrate spacer 24 is arranged between the upper substrate 26 and the lower substrate 22. The sensor 20A comprises at least one electrode spacer 90 arranged inside the substrate spacer 24 so that the lower electrode 50 and the upper electrode 60 opposed to each other are separated from each other. At least one electrode spacer 90 is formed so that a length in a first direction becomes longer than a length in a second direction.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a grip detection device and a sensor, and more particularly to a sensor used in a grip detection device for detecting that a driver grips a rim of a steering wheel of an automobile.

  Various sensors are mounted on the automobile, and various devices are controlled using signals detected by these sensors. For example, a car navigation system, a driving support system, a heater, an airbag, and the like are controlled depending on whether or not the driver is holding a rim of a steering wheel. Thus, in order to detect whether or not the driver has gripped the rim, a plurality of touch sensors are incorporated in the rim, and these touch sensors detect whether or not the driver's hand is in contact with the rim. (For example, refer to Patent Document 1).

  In order to more accurately detect the grip state of the rim, it is necessary to be able to detect the grip of the rim over a wide range. For this reason, in the technique disclosed in Patent Document 1, a plurality of touch sensors are arranged at equal intervals along the circumferential direction of the rim to widen the detection range. However, since these touch sensors independently determine contact or non-contact, there is a problem that wiring is required by the number of touch sensors, which complicates wiring and increases costs. .

JP 2014-061761 A

  The present invention has been made in view of such problems of the prior art, and a first object thereof is to provide a sensor having a wide detection range with a simple circuit configuration.

  In addition, a second object of the present invention is to provide a grip detection device that can accurately detect that the driver grips the rim.

  According to the first aspect of the present invention, a sensor having a wide detection range with a simple circuit configuration is provided. This sensor is incorporated in the rim of the steering wheel. The sensor faces a lower substrate that can be attached to the rim, an upper substrate that is disposed above the lower substrate, a lower electrode that is attached to an upper surface of the lower substrate, and the lower electrode. As described above, at least one electrode pair constituted by an upper electrode attached to the lower surface of the upper substrate, and a substrate spacer disposed around the at least one electrode pair. At least one of the upper electrode and the lower electrode is constituted by a pressure sensitive electrode. The substrate spacer is disposed between the upper substrate and the lower substrate. The sensor includes at least one electrode spacer disposed on the inner side of the substrate spacer such that the lower electrode and the upper electrode facing each other are separated from each other. The at least one electrode spacer has a length in a first direction corresponding to a circumferential direction of a rim cross section perpendicular to a direction in which the rim extends, and a length in a second direction corresponding to a direction in which the rim extends. It is formed to be long.

  As described above, since at least one of the upper electrode and the lower electrode is composed of pressure-sensitive electrodes, detection based on the pressing force acting on the pressure-sensitive electrodes is possible, not simply detection based on contact or non-contact between the electrodes. It becomes. Therefore, it is possible to detect the grip state of the rim even if the area of each electrode is increased, and a wide detection range can be secured. Thus, since the area of each electrode can be increased, the total number of electrodes can be reduced. Accordingly, since the number of wirings is reduced, the circuit configuration of the sensor can be simplified and the cost can be reduced. In addition, the length of the electrode spacer in the first direction corresponding to the circumferential direction of the rim cross section perpendicular to the extending direction of the rim is longer than the length of the electrode spacer in the second direction corresponding to the extending direction of the rim. Therefore, even when the sensor having a large electrode area is curved as described above, the electrode spacer is interposed inside the substrate spacer provided around the pair of electrodes. Unintentional contact with the lower electrode can be prevented.

  In this case, the at least one electrode spacer may be formed so that the length in the first direction is longer than the maximum width in the second direction. The at least one electrode spacer may be formed such that the upper surface of the lower electrode or the lower surface of the upper electrode intersects with a straight line extending in the first direction at an angle of 0 degree or more and less than 45 degrees. . Further, the at least one electrode spacer may extend along the first direction. In addition, the at least one electrode spacer may be provided at or near the center of the lower electrode or the upper electrode facing each other in the second direction. With such a configuration, it is possible to effectively prevent the upper electrode and the lower electrode from contacting each other unintentionally.

  The at least one electrode pair may be arranged with a plurality of electrode pairs along the second direction. In this case, it further comprises an upper electric wire connected to the upper electrode and a lower wiring connected to the lower electrode, and at least one of the upper wiring and the lower wiring is in the second direction. It is preferable that different channels are connected to a plurality of electrode pairs arranged along the same line. With such a configuration, independent detection can be performed according to the position of the electrode pair in the second direction, so that more accurate grip detection can be performed.

  A plurality of electrode pairs may be arranged along the first direction. In this case, it further comprises an upper electric wire connected to the upper electrode and a lower wiring connected to the lower electrode, and at least one of the upper wiring and the lower wiring is in the first direction. It is preferable that different channels are connected to a plurality of electrode pairs arranged along the same line. With such a configuration, independent detection can be performed according to the position of the electrode pair in the first direction, so that more accurate grip detection can be performed.

  According to the second aspect of the present invention, there is provided a grip detection device that can accurately detect that the driver grips the rim. The grip detection device includes the above-described sensor incorporated in the rim of the steering wheel, and a grip detection unit connected to the upper electrode and the lower electrode of the sensor. The grip detection unit detects that the driver grips the rim based on a conduction state between the upper electrode of the sensor and the lower electrode facing the upper electrode.

  Since the above-described sensor has a wide detection range, the grip detection device having such a configuration can detect the grip of the rim over a wide range, and can accurately detect that the driver has gripped the rim. Can be detected.

  In this case, the grip detection device may further include a cushion material provided between the outer peripheral surface of the core of the rim and the lower surface of the lower electrode. With such a configuration, even when the pressure sensor of the grip detection device is pressed, the cushion material absorbs the pressing, so that the upper electrode and the lower electrode are effectively prevented from coming into contact with each other. be able to. Such a cushion material may be formed of urethane.

  According to the present invention, it is possible to provide a sensor having a wide detection range with a simple circuit configuration. Further, it is possible to provide a grip detection device that can accurately detect that the driver grips the rim.

It is a figure which shows typically the structure of the holding | grip detection apparatus in one Embodiment of this invention. It is a figure which shows typically the AA line cross section of FIG. It is a top view which shows the sensor in the holding | grip detection apparatus shown in FIG. 1, and shows the state of the sensor before incorporating in the rim | limb of a steering wheel. FIG. 4 is a bottom view of the sensor shown in FIG. 3. FIG. 4 is a sectional view taken along line BB in FIG. 3. It is CC sectional view taken on the line of FIG. FIG. 6 is a plan view of the substrate spacer shown in FIG. 5. It is the DD sectional view taken on the line of FIG. It is the EE sectional view taken on the line of FIG. It is a figure which shows the state which attached the sensor shown in FIG. 3 to the core of the rim | limb. It is a figure corresponding to FIG. 6 of the modification of the sensor shown in FIG. It is a figure corresponding to FIG. 8 of the sensor shown in FIG. It is a figure which shows the modification of the sensor shown in FIG. FIG. 6 is a bottom view schematically showing an upper electrode and an upper wiring formed on the upper substrate of the sensor shown in FIG. 5. FIG. 6 is a plan view schematically showing a lower electrode and a lower wiring formed on the lower substrate of the sensor shown in FIG. 5. It is a figure which shows typically the circuit structure of the holding | grip detection apparatus shown in FIG. It is a figure which shows typically the circuit structure of the holding | grip detection apparatus shown in FIG. It is a figure which shows typically the circuit structure of the holding | grip detection apparatus shown in FIG. It is a figure which shows the manufacturing process of the sensor shown in FIG. It is a figure which shows the manufacturing process of the sensor shown in FIG. It is a figure which shows the manufacturing process of the sensor shown in FIG. It is a figure which shows the manufacturing process of the sensor shown in FIG. It is a figure which shows the manufacturing process of the sensor shown in FIG. It is a figure which shows the manufacturing process of the sensor shown in FIG. It is a figure which shows the manufacturing process of the sensor shown in FIG. It is a figure which shows the manufacturing process of the sensor shown in FIG. It is a figure which shows the manufacturing process of the sensor shown in FIG. It is a figure which shows the manufacturing process of the sensor shown in FIG. It is a figure which shows the manufacturing process of the sensor shown in FIG. It is a figure which shows the resistance value between the upper side electrode and lower side electrode of an electrode pair in the Example of the sensor which concerns on this invention. It is a figure which shows the resistance value between the upper side electrode and lower side electrode of an electrode pair in the comparative example with respect to the Example of the sensor which concerns on this invention.

  Hereinafter, an embodiment of a grip detection device according to the present invention will be described in detail with reference to FIGS. 1 to 22. 1 to 22, the same or corresponding components are denoted by the same reference numerals, and redundant description is omitted. In FIGS. 1 to 22, the scale and dimensions of each component are exaggerated, and some components may be omitted.

  FIG. 1 is a diagram schematically illustrating a configuration of a grip detection device 1 according to an embodiment of the present invention. As shown in FIG. 1, the grip detection device 1 includes three pressure sensors 20 </ b> A, 20 </ b> B, and 20 </ b> C incorporated in the rim 12 of the steering wheel 10 and a grip detection unit 30 disposed in the hub 14 of the steering wheel 10. And a connection wiring portion 40 that electrically connects each of the pressure sensitive sensors 20A, 20B, and 20C and the grip detection unit 30. Each of the pressure sensitive sensors 20A, 20B, and 20C has connection portions 21A, 21B, and 21C that are connected to the connection wiring portion 40 that extends from the grip detection portion 30 in the hub 14 through the inside of the spoke 15 of the steering wheel 10. doing.

  The pressure sensor 20A is provided from the left region H to the upper region J of the rim 12, and the pressure sensor 20B is provided from the right region M to the upper region J of the rim 12, and pressure sensitive. The sensor 20 </ b> C is provided in a portion of the region K below the rim 12. Hereinafter, the pressure sensor 20A among the three pressure sensors 20A, 20B, and 20C will be mainly described. However, the configuration of the other pressure sensors 20B and 20C is the same as the configuration of the pressure sensor 20A described below. It is. The positions and number of the pressure sensitive sensors 20A, 20B, and 20C are not limited to those shown in the drawing. For example, the number of pressure sensors may be one, two, or four or more.

  FIG. 2 is a diagram schematically showing a cross section taken along line AA of FIG. The upper side in FIG. 2 indicates the front side of the rim 12 (the front side in FIG. 1), and the lower side indicates the back side in the rim 12 (the back side in FIG. 1). As shown in FIG. 2, a cushion material 300 is provided around the outer peripheral surface of the core 16 of the rim 12. The pressure-sensitive sensor 20A is mounted on such a cushioning material 300 so as to cover substantially the entire outer peripheral surface of the cross section of the core 16 of the rim 12. In addition, you may comprise such a cushioning material 300 with urethane etc., for example.

  A buffer material 17 is provided on the outer peripheral surface of the pressure-sensitive sensor 20 </ b> A so as to absorb unevenness caused by the pressure-sensitive sensor 20 </ b> A and prevent the unevenness on the surface of the rim 12. The outer peripheral surface of the cushioning material 17 is covered with a skin 18 made of leather or the like, and the driver operates the automobile by grasping the rim 12 from the skin 18.

  As shown in FIG. 2, the pressure-sensitive sensor 20 </ b> A includes a lower substrate 22 attached on the cushioning material 300, a substrate spacer 24 fixed on the lower substrate 22, and an upper side fixed on the substrate spacer 24. The substrate 26, a plurality of lower electrodes 50 attached to the upper surface of the lower substrate 22, a plurality of upper electrodes 60 attached to the lower surface of the upper substrate 26, and the lower electrode 50 and the upper electrode 60 facing each other And at least one electrode spacer 90 disposed therebetween. In the present embodiment, the lower electrode 50 and the upper electrode 60 facing each other are separated from each other by an electrode spacer 90, and the lower electrode 50 and the upper electrode 60 constitute one electrode pair 80.

  FIG. 3 is a plan view showing the pressure-sensitive sensor 20A before being incorporated into the rim 12, and FIG. 4 is a bottom view. 5 is a cross-sectional view taken along line BB in FIG. 3, and FIG. 6 is a cross-sectional view taken along line CC in FIG. As shown in FIGS. 3 and 4, the upper substrate 26 and the lower substrate 22 have the same outer shape and are formed of a flexible resin such as polyimide or polyethylene terephthalate (PET). . 3 and 4, the X direction (first direction) is the circumference of the rim cross section (cross section of the core 16) perpendicular to the direction in which the rim 12 extends when the pressure-sensitive sensor 20A is attached to the outer peripheral surface of the core 16. It corresponds to the direction R (see FIG. 2), and the Y direction (second direction) corresponds to the direction E (see FIG. 1) in which the rim 12 (core 16) extends. Hereinafter, the direction in which the rim 12 (core 16) extends may be referred to as a rim extending direction E, and the circumferential direction of the rim section may be referred to as a rim section circumferential direction R.

  As shown in FIG. 3, the upper substrate 26 is made of a substantially rectangular plate material that is long in the Y direction, and notches 70 are formed on both sides in the X direction at predetermined intervals along the Y direction. By forming such a notch 70, the upper substrate 26 has a structure in which a plurality of substantially strip-shaped substrate pieces 26A are connected in the Y direction. Similarly, as shown in FIG. 4, the lower substrate 22 is made of a substantially rectangular plate material that is long in the Y direction, and notches 71 are formed on both sides in the X direction at predetermined intervals along the Y direction. Has been. By forming such a notch 71, the lower substrate 22 has a structure in which a plurality of substantially strip-shaped substrate pieces 22A are connected in the Y direction.

  As shown in FIGS. 5 and 6, a substrate spacer 24 is disposed between the upper substrate 26 and the lower substrate 22. Here, FIG. 7 is a plan view of the substrate spacer 24. As shown in FIG. 7, the substrate spacer 24 has substantially the same outer shape as the upper substrate 26 and the lower substrate 22, and is formed of a flexible resin such as polyimide or polyethylene terephthalate (PET). Can be done. The substrate spacer 24 is made of a substantially rectangular plate material that is long in the Y direction, and notches 72 are formed on both sides in the X direction at predetermined intervals along the Y direction. By forming such a notch 72, the substrate spacer 24 has a structure in which a plurality of substantially strip-shaped substrate spacer pieces 24A are connected in the Y direction.

  Thus, the pressure-sensitive sensor 20A has a laminated structure in which the lower substrate 22, the substrate spacer 24, and the upper substrate 26, which have substantially the same outer shape, overlap each other. That is, it has a laminated structure in which the substrate spacer 24 is disposed on the lower substrate 22 and the upper substrate 26 is disposed on the substrate spacer 24 (see FIG. 5). Here, one substrate piece 22A of the lower substrate 22, a substrate spacer piece 24A disposed thereon, a lower electrode 50 formed on the substrate piece 22A, and an upper portion disposed on the substrate spacer piece 24A. A substrate piece 26A of the substrate 26, an upper electrode 60 formed on the substrate piece 26A, and an electrode spacer 90 disposed between the lower electrode 50 and the upper electrode 60 are grouped into an electrode unit 75 (FIG. 3). (See FIG. 6). In the present embodiment, each electrode unit 75 has two electrode pairs 80 arranged along the X direction, and a single electrode spacer 90 is arranged for each electrode pair 80 (FIG. 5 and FIG. 6). That is, the electrode unit 75 in the present embodiment includes two electrode spacers 90. The pressure-sensitive sensor 20A has a structure in which a plurality of such electrode units 75 (15 in this embodiment) are connected in the Y direction (see FIGS. 3 and 4).

  In the present embodiment, the electrode unit 75 includes two electrode pairs 80 (see FIG. 5). However, the present invention is not limited to this, and the electrode unit 75 may include only one electrode pair. Alternatively, three or more electrode pairs may be included. In this embodiment, the pressure sensor 20A has a structure in which 15 electrode units 75 are connected in the Y direction (see FIGS. 3 and 4), but the number of electrode units can be changed as appropriate. Not too long.

  Here, as shown in FIG. 7, two through holes 25, 25 corresponding to the upper electrode 60 and the lower electrode 50 are formed in each substrate spacer piece 24 </ b> A of the substrate spacer 24 along the X direction. Are formed at intervals. In the present embodiment, two through holes 25 are formed in the substrate spacer piece 24 </ b> A corresponding to the two electrode pairs 80 constituting the electrode unit 75. The number of through holes 25 may be changed according to the number of pairs.

  Referring again to FIGS. 5 and 6, the upper electrode 60 and the lower electrode 50 (that is, the electrode pair 80) facing each other are positioned in the through hole 25 of the substrate spacer 24. That is, the substrate spacers 24 are located on both sides of each electrode pair 80 in the X direction. In this embodiment, the substrate spacer 24 is arranged so as to surround the electrode pair 80. The lower substrate 22 and the upper substrate 26 constituting each electrode unit 75 are separated from each other by the substrate spacer 24. Thus, the pressure sensitivity is maintained while the lower substrate 22 and the upper substrate 26 are separated from each other. The sensor 20 </ b> A can be attached to the outer peripheral surface of the core 16.

  In the electrode unit 75 in FIG. 5, two electrode pairs 80 are formed along the X direction. Here, the upper electrode 60 and the lower electrode 50 constituting each electrode pair 80 have dimensions slightly smaller than the through-hole 25 and have substantially the same rectangular outer shape. With such a configuration, the lower electrode 50 and the upper electrode 60 forming the electrode pair 80 are entirely opposed to each other. The substrate spacer 24 may be disposed between the lower substrate 22 and the upper substrate 26 so that the lower substrate 22 and the upper substrate 26 constituting the electrode unit 75 are separated from each other. The upper electrode 60 and the lower electrode 50 that are configured may be slightly larger than the through-hole 25, and the substrate spacer 24 may be disposed so as to surround the periphery (periphery) of the upper electrode 60 and the lower electrode 50. .

  8 is a cross-sectional view taken along line DD in FIG. 5, and FIG. 9 is a cross-sectional view taken along line EE in FIG. As shown in FIGS. 8 and 9, the upper electrode 60 and the lower electrode 50 have the same outer shape that is substantially rectangular, and face each other as described above. The upper electrode 60 and the lower electrode 50 are surrounded by the substrate spacer 24. Therefore, when the pressure sensitive sensor 20A is attached to the outer peripheral surface of the core 16, the substrate spacers 24 are located on both sides of the rim cross-section circumferential direction R and both sides of the rim extending direction E of each electrode pair 80. Become. With such a configuration, the pressure-sensitive sensor 20A is attached to the outer peripheral surface of the core 16 with the lower substrate 22 and the upper substrate 26 separated from each other (see FIG. 2).

  As shown in FIGS. 8 and 9, an elongated electrode spacer 90 extending in the X direction is disposed at the center of the electrode pair 80 in the Y direction inside the substrate spacer 24 surrounding the electrode pair 80. . That is, between the lower electrode 50 and the upper electrode 60 facing each other, an elongated electrode spacer 90 extending in the X direction is disposed at the center of the electrode pair 80 in the Y direction. The electrode spacer 90 is configured as a generally linear spacer whose width in the Y direction is extremely short compared to the length in the X direction. Such an electrode spacer 90 extends from one end in the X direction of the electrode pair 80 to the other end, and connects the upper surface 50A of the lower electrode 50 and the lower surface 60A of the upper electrode 60 ( (See FIG. 6). With such a configuration, the lower electrode 50 and the upper electrode 60 that form the electrode pair 80 are separated from each other, and the lower electrode 50 and the upper electrode are mounted even when the pressure-sensitive sensor 20A is attached to the outer peripheral surface of the core 16. The state where 60 is separated from each other is maintained (see FIG. 2). Such an electrode spacer 90 may be formed of a flexible material such as silicon rubber.

  FIG. 10 is a plan view showing a state in which the pressure-sensitive sensor 20A is attached to the core 16 of the rim 12, and shows a state before the pressure-sensitive sensor 20A is covered with the skin 18 (see FIG. 2). As shown in FIG. 10, the pressure sensor 20 </ b> A is attached so that the center in the X direction of the pressure sensor 20 </ b> A is along the outer periphery of the annular portion of the core 16 (along the rim extending direction E). Here, as described above, since the notches 70, 71, 72 are formed between the electrode units 75 adjacent to each other, the rim extending direction E when the pressure-sensitive sensor 20A is attached to the outer peripheral surface of the core 16. It is possible to prevent the electrode units 75 adjacent to each other from overlapping, and to increase the area where the pressure-sensitive sensor 20A covers the outer peripheral surface of the core 16.

  Here, the lower electrode 50 and the upper electrode 60 in the present embodiment are configured as pressure-sensitive electrodes whose resistance value changes depending on the pressing force. As will be described later, for example, silver is a pressure-sensitive material such as carbon. It is formed by coating with. Unlike a contact-type sensor that detects only whether or not two opposing electrodes are in contact with each other, such a pressure-sensitive electrode can detect a force pressed by a change in resistance value. By increasing the area, the detection range can be expanded.

  2 and 10, when the pressure sensor 20A is attached to the rim 12, the pressure sensor 20A is greatly curved along the circumferential direction R of the rim cross section (that is, the Z direction shown in FIG. 5). Therefore, if the area of the lower electrode 50 and the upper electrode 60 constituting each electrode pair 80 is to be increased, the upper electrode 60 is not attached to the rim 12 when the pressure sensor 20A is attached to the rim 12. It is conceivable that the lower electrode 50 is bent and contacts. In such a state, even when the driver is not gripping the rim 12, the electrode pair 80 is always in a conductive state, so that the grip detection unit 30 cannot accurately detect the grip.

  The inventors have conducted intensive research to solve such problems, and as a result, electrode spacers having a length in the X direction longer than a length in the Y direction are connected to the lower electrode 50 and the upper electrode 60 of the electrode pair 80. Even when a pressure-sensitive sensor (for example, pressure-sensitive sensor 20A) having a larger electrode area is attached to the rim 12, the lower electrode 50 and the upper electrode 60 It has been found that there is an effect of preventing the two from contacting each other. That is, when the pressure sensor 20A is attached to the rim 12, the electrode spacer 90 is disposed so that the electrode spacer 90 extends along the circumferential direction R of the rim cross section. It has been found that contact with 60 can be prevented. In particular, as will be described later, a linear electrode spacer 90 extending in the X direction in the vicinity of the center in the Y direction of the electrode pair 80 is disposed between the lower electrode 50 and the upper electrode 60 of the electrode pair 80. It was found that there was a remarkable effect.

  As shown in FIGS. 8 and 9, in this embodiment, a single electrode spacer 90 extending in the X direction at the center in the Y direction of the electrode pair 80 is formed between the lower electrode 50 and the upper electrode 60 of the electrode pair 80. Arranged between. Therefore, even when the area of the upper electrode 50 and the lower electrode 60 is increased, the upper electrode 50 and the lower electrode 60 are prevented from contacting unintentionally when the pressure sensitive sensor 20A is attached to the rim 12. (See FIG. 2).

  Further, as described above, the cushion material 300 (see FIG. 2) is disposed between the lower substrate 22 and the core 16 of the rim 12. With such a configuration, even when the electrode pair 80 is pressed from above in order to curve the pressure-sensitive sensor 20A, this pressing can be absorbed by the cushion material 300. Therefore, the lower electrode 50 and the upper electrode 60 of the electrode pair 80 can be more effectively prevented from contacting each other unintentionally. Even when the cushion material 300 is not provided, it is possible to prevent the lower electrode 50 and the upper electrode 60 from contacting each other as will be described later.

  That is, according to the present embodiment, the lower electrode 50 and the upper electrode 60 of the electrode pair 80 are not in contact with each other simply by being attached to the rim 12, and are not contacted with the lower substrate 22 from the outside of the upper substrate 26. Only when the upper substrate 26 and the electrode spacer 90 are bent toward the core 16, the upper electrode 60 in that portion comes into contact with the lower electrode 50. Therefore, the areas of the upper electrode 60 and the lower electrode 50 can be increased, the detection range can be widened, and the number of electrodes can be reduced to simplify the wiring.

  By the way, the number of the electrode spacers 90 provided between the lower electrode 50 and the upper electrode 60 of the electrode pair 80 is not limited to one. Here, FIG. 11 is a diagram corresponding to FIG. 6 of a modified example of the pressure sensor 20A, and FIG. 12 is a diagram corresponding to FIG. 8 of the pressure sensor shown in FIG. 11 and 12, between the lower electrode 50 and the upper electrode 60 of the electrode pair 80, in the vicinity of the center portion in the Y direction of the electrode pair 80 (on both sides of the center portion). Two linear electrode spacers 90, 90 are arranged. Even in such a configuration, an effect equivalent to that of the pressure-sensitive sensor provided with the single electrode spacer 90 can be obtained as will be described later.

  However, if the number of the electrode spacers 90 is too large, when the driver grips the steering wheel, the possibility that the electrode spacers 90 are arranged on the gripped rim 12 portion increases. If the electrode spacer 90 is disposed at the portion where the driver grips the rim 12, the lower electrode 50 and the upper electrode 50 are not in contact with each other, so the lower electrode 50 and the upper electrode 60 do not conduct and “gripping”. May not be detected. It is also conceivable that the manufacturing cost increases as the number of electrode spacers 90 increases. Therefore, it is preferable to adjust the number of electrode spacers provided between the lower electrode 50 and the upper electrode 60 of the electrode pair 80 based on such a viewpoint. Specifically, the number of electrode spacers 90 provided between the lower electrode 50 and the upper electrode 60 of the electrode pair 80 is preferably one or two.

  By the way, from the viewpoint of “disposing the electrode spacer 90 so that the electrode spacer 90 extends along the circumferential direction R of the rim when the pressure-sensitive sensor 20A is attached to the rim 12,” the electrode spacer is not necessarily X. It does not have to extend in the direction. That is, a certain effect can be obtained by forming the electrode spacer so that the length in the X direction is longer than the length in the Y direction. For example, as shown in FIG. 13, a pressure-sensitive sensor provided with a linear electrode spacer 91 extending so as to intersect the lower surface 60A of the upper electrode 60 with respect to a straight line L extending in the X direction at an angle of 0 to less than 45 degrees. May be configured. Furthermore, even when the electrode spacer is formed in a curved shape, if the length of the electrode spacer in the X direction is longer than the maximum width in the Y direction of the electrode spacer, the electrode spacer is in the X direction. Therefore, it is possible to obtain a certain effect.

  FIG. 14 is a bottom view schematically showing the upper substrate 26 together with the upper electrode 60 and the wiring. As shown in FIG. 14, a common wiring 62A is connected to each upper electrode 60, and the upper electrodes 60 are connected to each other via the wiring 62A. Further, a wiring 62B extending to the terminal 41 provided in the connection portion 21A is connected to the upper electrode 60AH close to the connection portion 21A of the pressure sensor 20A. Accordingly, all the upper electrodes 60 are electrically connected to the terminal 41 by one common wiring (upper wiring) 62. By connecting the terminal 41 to a terminal of a connection wiring unit 40 (see FIG. 1) extending from the grip detection unit 30, the grip detection unit 30 and the upper electrode 60 are electrically connected.

  As shown in FIG. 14, when the upper electrode 60 in the present embodiment is incorporated into the rim 12, five upper electrodes 60 </ b> AJ disposed on the front side of the region J (see FIG. 1) above the rim 12, Five upper electrodes 60BJ disposed on the back side of the region J on the upper side of the rim 12, ten upper electrodes 60AH disposed on the front side of the region H on the left side of the rim 12 (see FIG. 1), and the left side of the rim 12 10 upper electrodes 60BH arranged on the back side of the region H.

  FIG. 15 is a plan view schematically showing the lower substrate 22 together with the lower electrode 50 and the wiring. As shown in FIG. 15, when the lower electrode 50 in this embodiment is incorporated in the rim 12, five lower electrodes 50 </ b> AJ disposed on the front side of the region J (see FIG. 1) on the upper side of the rim 12. And five lower electrodes 50BJ disposed on the back side of the upper region J of the rim 12, and ten lower electrodes 50AH disposed on the front side of the left region H (see FIG. 1) of the rim 12, 10 lower electrodes 50BH disposed on the back side of the region H on the left side of the rim 12 are included.

  In addition to the lower electrode 50, five wirings 51 to 55 (lower wiring) that are electrically connected to the lower electrode 50 are formed on the lower substrate 22. In the present embodiment, the wiring 51 is connected to the five lower electrodes 50AJ arranged on the front side of the region J of the rim 12, and extends to the terminal 42 provided in the connecting portion 21A. The wiring 52 is connected to the five lower electrodes 50BJ disposed on the back side of the region J of the rim 12, and extends to the terminal 43 provided in the connecting portion 21A. The wiring 53 is connected to the five lower electrodes 50AH arranged on the front side of the region H of the rim 12, and extends to the terminal 44 provided in the connecting portion 21A. The wiring 54 is connected to five lower electrodes 50AH arranged on the front side of the region H of the rim 12, and extends to the terminal 45 provided in the connection portion 21A. The wiring 55 is connected to ten lower electrodes 50BH arranged on the back side of the region H of the rim 12, and extends to the terminal 46 provided in the connecting portion 21A. These terminals 42 to 46 are connected to the terminals of the connection wiring part 40 (see FIG. 1) extending from the grip detection part 30, whereby the grip detection part 30 and the lower electrode 50 are electrically connected.

  16 to 18 are diagrams schematically illustrating a circuit configuration of the grip detection device 1. In FIG. 16 to FIG. 18, for easy understanding, only wiring for one electrode unit 75 among the plurality of electrode units 75 arranged in the region J of the rim 12 is illustrated, and other electrode units are illustrated. The wiring is not shown. As illustrated in FIGS. 16 to 18, the grip detection unit 30 is configured to detect the gripping state of the rim 12 of the steering wheel 10 based on the detection circuits 32AJ and 32BJ and outputs from the detection circuits 32AJ and 32BJ. 34.

  The detection circuit 32AJ is connected between the wiring 62 connected to the upper electrode 60AJ and the wiring 51 connected to the lower electrode 50AJ, and detects continuity between the wiring 62 and the wiring 51. is there. The detection circuit 32BJ is connected between the wiring 62 connected to the upper electrode 60BJ and the wiring 52 connected to the lower electrode 50BJ, and detects continuity between the wiring 62 and the wiring 52. is there. That is, the detection circuit 32AJ detects the contact between the upper electrode 60AJ and the lower electrode 50AJ and its contact pressure, and the detection circuit 32BJ detects the contact between the upper electrode 60BJ and the lower electrode 50BJ and its contact pressure. To do.

  When the driver grips the rim 12 of the steering wheel 10, the gripping force causes the gripped portion of the upper substrate 26 to be pushed toward the core 16 and bend. Along with this, the upper electrode 60 in that portion comes into contact with the lower electrode 50 and the electrode pair 80 becomes conductive, and the current changes due to a change in resistance value according to the contact pressure. The detection circuits 32 </ b> AJ and 32 </ b> BJ detect conduction between the electrode pair and change in current (change in contact pressure) caused by gripping the rim 12. The determination unit 34 determines whether or not the driver is holding the rim 12 according to the detection results from the detection circuits 32AJ and 32BJ.

  At this time, the determination unit 34 can determine the gripping state of the rim 12 according to an arbitrary standard. For example, it may be determined that there is a gripping state when there are one or more detection circuits in which a current exceeding a predetermined threshold flows, or a predetermined number or more of detection circuits in which a current exceeding a predetermined threshold flows. It may be determined that it is in a gripping state at a certain time, or may be determined to be in a gripping state when a plurality of detection circuits in which a current exceeding a predetermined threshold is in a specific positional relationship, Various other criteria can be set. The determination unit 34 in the present embodiment holds when the current flowing in both the detection circuit 32AJ corresponding to the front electrode pair 80A of the rim 12 and the detection circuit 32BJ corresponding to the back electrode pair 80B exceeds a predetermined threshold. Assume that it is in a state.

  FIG. 16 shows a state where the driver is not gripping the rim 12 of the steering wheel 10. In this state, since the upper electrode 60 is separated from the lower electrode 50 in both the electrode pairs 80A and 80B, none of the wirings 51 and 52 is electrically connected to the wiring 62. Therefore, the detection circuits 32AJ and 32BJ of the grip detection unit 30 do not detect the continuity of the electrode pairs 80A and 80B, and the determination unit 34 that receives the output from the detection circuits 32AJ and 32BJ grips the rim 12. Judge that it is not.

  FIG. 17 shows a state where the driver's hand is in contact with the front side of the rim 12 of the steering wheel 10. In this state, the upper electrode 60AJ of the electrode pair 80A is in contact with the lower electrode 50AJ. As a result, the detection circuit 32AJ of the grip detection unit 30 detects the continuity of the electrode pair 80A, and when the contact pressure of the electrode pair 80A exceeds a predetermined value (when the flowing current exceeds a predetermined threshold), this detection result ( Detection signal) is sent to the determination unit 34. At this time, the detection circuit 32BJ corresponding to the back side of the rim 12 does not detect the continuity of the electrode pair 80B, and “corresponding to the detection circuit 32AJ corresponding to the electrode pair 80A on the front side of the rim 12 and the electrode pair 80B on the back side. Since the determination condition of the gripping state that the current flowing in both of the detection circuits 32BJ exceeds a predetermined threshold is not satisfied, the determination unit 34 determines that the driver is not gripping the rim 12.

  FIG. 18 shows a state where the driver holds the rim 12 of the steering wheel 10. In this state, the upper electrode 60AJ of the electrode pair 80A is in contact with the lower electrode 50AJ, and the upper electrode 60BJ of the electrode pair 80B is in contact with the lower electrode 50BJ. Thereby, when the detection circuits 32AJ and 32BJ of the grip detection unit 30 detect the continuity of the electrode pairs 80A and 80B, and the contact pressure of the electrode pairs 80A and 80B exceeds a predetermined value (when the flowing current exceeds a predetermined threshold value). ) And the detection result (detection signal) is sent to the determination unit 34. At this time, the currents flowing in both the front electrode pair 80A and the back electrode pair 80B of the rim 12 exceed a predetermined threshold, and “the detection circuit 32AJ corresponding to the front electrode pair 80A of the rim 12 and the back electrode Since the determination condition of the gripping state that the current flowing in both of the detection circuits 32BJ corresponding to the pair 80B exceeds a predetermined threshold is satisfied, the determination unit 34 determines that the driver is gripping the rim 12. The control signal is output to an external car navigation system, a driving support system, a heater, an airbag, or the like.

  As described above, in the present embodiment, since the upper electrode 60 and the lower electrode 50 are configured by pressure-sensitive electrodes, the detection is not performed simply by contact or non-contact between the electrodes 50, 60, but by the electrodes 50, 60. Detection based on the applied pressing force is possible. Therefore, even when the area of each electrode 50, 60 is increased, the gripping state of the rim 12 can be detected, and a wide detection range can be secured. Thus, since the area of each electrode 50 and 60 can be enlarged, the total number of electrodes 50 and 60 can be reduced. Accordingly, since the number of wirings is reduced, the circuit configuration of the pressure sensor 20A can be simplified and the cost can be reduced.

  In the example shown in FIGS. 16 to 18, the lower side electrode 50AJ on the front side of the rim 12 and the lower side electrode 50BJ on the back side are connected by the wiring 51 and the wiring 52 of different channels. And independent detection on the back side. Therefore, for example, by determining that the driver is holding the rim 12 only when the detection signal is sent from both the detection circuit 32AJ and the detection circuit 32BJ to the determination unit 34 as in the above-described example, The gripping state can be detected only when the driver firmly grips the front side and the back side of the rim 12.

  Further, as shown in FIG. 15, for example, the lower electrode 50BJ and the lower electrode 50BH arranged along the Y direction corresponding to the extending direction of the rim 12 are connected by the wiring 52 and the wiring 55 of different channels. Therefore, independent detection can be performed according to the position of the electrode pair 80 in the Y direction, so that more accurate grip detection can be performed.

  In the embodiment described above, the wiring 62 (upper wiring) connected to the upper electrode 60 is a single common wiring, and the wirings 51 to 55 (lower wiring) connected to the lower electrode 50 are wirings of different channels. However, this may be reversed. That is, the wiring connected to the upper electrode 60 may be a wiring of a different channel, and the wiring connected to the lower electrode 50 may be a single common wiring.

  Next, a manufacturing method of the pressure-sensitive sensor 20A in the present embodiment will be described in detail with reference to FIGS. 19A to 19E and FIGS. 20A to 20F. The manufacturing method of the pressure-sensitive sensor 20A includes an upper-layer stacked body forming step (first stacked body forming) for forming an upper stacked body (first stacked body) constituting the upper half of the pressure-sensitive sensor 20A shown in FIG. Step), a lower laminate forming step (second laminate forming step) for forming a lower laminate (second laminate) constituting the lower half of the pressure-sensitive sensor 20A, an upper laminate, and a lower laminate A laminated body joining step of joining the side laminated body to form the pressure sensitive sensor 20A. In the upper laminate forming process and the lower laminate forming process, a predetermined material is printed by a printing apparatus (not shown) and these materials are laminated to form the upper laminate and the lower laminate.

More specifically, the upper laminate forming process includes the following steps.
(Step A1)
A thin flexible substrate made of an insulating material, for example, a flexible resin film (made of polyimide, PET, or the like) is cut into a predetermined shape to prepare an upper substrate 26 as shown in FIG. 19A.
(Step A2)
Next, a conductive material, for example, silver paste is printed on the upper substrate 26, and a plurality of electrode portions 160, wirings 62 (upper wirings) and terminals 41 connected thereto are formed as shown in FIG. 19B.
(Step A3)
Then, pressure-sensitive ink 161 made of a pressure-sensitive material, such as carbon, is printed on the electrode portion 160 to form the upper electrode 60 as a pressure-sensitive electrode as shown in FIG. 19C.
(Step A4)
Thereafter, as shown in FIG. 19D, an insulating material (resist) 171 is printed around the upper electrode 60 on the upper substrate 26.
(Step A5)
Finally, as shown in FIG. 19E, an adhesive 181 is printed on the resist 171 to form an upper substrate spacer 191 composed of the resist 171 and the adhesive 181. Thereby, the upper laminated body 201 is completed.

Further, the lower laminate forming process includes the following steps.
(Step B1)
A thin flexible substrate made of an insulating material, for example, a flexible resin film (made of polyimide, PET, or the like) is cut into a predetermined shape to prepare a lower substrate 22 as shown in FIG. 20A.
(Step B2)
Next, a conductive material, for example, silver paste is printed on the lower substrate 22, and as shown in FIG. 20B, a plurality of electrode portions 150, wirings 51 to 55 (lower wirings) connected thereto, and terminals 42 to 46 are connected. Form.
(Step B3)
Then, a pressure-sensitive ink 162 made of a pressure-sensitive material, such as carbon, is printed on the electrode portion 150, and the lower electrode 50 as a pressure-sensitive electrode is formed as shown in FIG. 20C.
(Step B4)
Thereafter, as shown in FIG. 20D, an insulating material (resist) 172 is printed around the lower electrode 50 on the lower substrate 22.
(Step B5)
Then, as illustrated in FIG. 20E, an adhesive material 182 is printed on the resist 172 to form a lower substrate spacer 192 including the resist 172 and the adhesive material 182.
(Step B6)
Next, an insulating material such as silicon rubber is printed on the lower electrode 50 to form a linear electrode spacer 90 as shown in FIG. 20F. Thereby, the lower laminated body 202 is completed.

  Next, the upper laminated body 201 formed by the above-described upper laminated body forming process and the lower laminated body 202 formed by the lower laminated body forming process are joined and integrated (laminate bonded process). At this time, the upper laminate 201 and the lower laminate 202 are overlapped so that the upper electrode 60 of the upper laminate 201 and the lower electrode 50 of the lower laminate 202 face each other. The upper laminate 201 and the lower laminate 202 are bonded together by the adhesive 181 of the upper substrate spacer 191 of the upper laminate 201 and the adhesive 182 of the lower substrate spacer 192 of the lower laminate 202. Thereby, the pressure sensitive sensor 20A is completed.

  Here, the adhesive 181 (see FIG. 19E) on the resist 171 of the upper laminate 201 and the adhesive 182 (see FIG. 20F) on the resist 172 of the lower laminate 202 correspond to the circumferential direction R of the rim cross section. Discontinuous portions 181A and 182A are formed in the direction. By forming such discontinuous portions 181A and 182A, the discontinuity portions 181A and 182A cause surface wrinkles generated on the upper substrate 26 and the lower substrate 22 when the completed pressure-sensitive sensor 20A is attached to the rim 12. The pressure sensor 20A can be easily attached to the rim 12.

  In the present embodiment, an example in which both the upper electrode 60 and the lower electrode 50 are pressure-sensitive electrodes has been described, but only one of the upper electrode 60 and the lower electrode 50 may be a pressure-sensitive electrode. In that case, step A3 or step B3 mentioned above becomes unnecessary.

  In addition, since Steps A2 to A5 and Steps B2 to B5 described above are similar steps, Step A2 and Step B2 are simultaneously performed using the same printing apparatus, and Step A3 and Step B3 are simultaneously performed. A4 and step B4 may be performed simultaneously, and step A5 and step B5 may be performed simultaneously. In that case, the manufacturing time of the pressure-sensitive sensor is shortened, so that the throughput is improved.

  Inventors performed the following experiment in order to investigate the performance of the electrode spacer which concerns on this invention. Specifically, the upper electrode 60 in which the width in the Y direction in the cross section of FIG. 8 is 15 mm and the length in the X direction is 35 mm, the width in the Y direction in the cross section in FIG. 9 is 15 mm, and the length in the X direction is 35 mm. The lower electrode 50 was used to form an electrode pair 80. A linear electrode extending in the X direction between the lower electrode 50 and the upper electrode 50 of the electrode pair 80 and formed so that the length in the X direction is 35 mm and the width in the Y direction is 0.053 mm. A sensor in which the spacer 90 is arranged is configured. When this sensor (electrode pair 80) was wound around a cylinder having a diameter of 25 mm, an experiment was conducted to measure the resistance value between the lower electrode 50 and the upper electrode 60 of the electrode pair 80. Note that a higher resistance value indicates that the lower electrode 50 and the upper electrode 60 of the electrode pair 80 are less likely to contact each other when the sensor is wound around a cylinder.

  As Example 1, a feeling that a single linear electrode spacer 90 is arranged at the center of the electrode pair 80 in the Y direction (that is, at a position of 7.5 mm from the respective ends of the electrodes 50 and 60 in the Y direction). A pressure sensor was used. Further, as Example 2, a pressure-sensitive sensor in which two linear electrode spacers 90 and 90 are arranged at a position of 6 mm from the respective end portions in the Y direction of the electrode pair 80 toward the central portion is used. Further, as Example 3, a pressure-sensitive sensor in which two linear electrode spacers 90 and 90 are disposed at a position of 5 mm from the respective end portions in the Y direction of the electrode pair 80 toward the central portion is used. Further, as Example 4, a pressure-sensitive sensor in which two linear electrode spacers 90 and 90 were arranged at a position of 4 mm from the respective end portions in the Y direction of the electrode pair 80 toward the center portion was used.

  As a comparative example, the resistance value was also measured for a sensor in which a linear electrode spacer extending in the Y direction was disposed between the lower electrode 50 and the upper electrode 50. The dimensions of the lower electrode 50 and upper electrode 50 of the electrode pair 80 used in the comparative example are the same as the dimensions of the lower electrode 50 and upper electrode 60 of the electrode pair 80 used in Examples 1-4. As Comparative Example 1, a pressure-sensitive element in which a single linear electrode spacer is arranged at the center of the electrode pair 80 in the X direction (that is, 17.5 mm from each end of the electrodes 50 and 60 in the X direction). A sensor was used. Further, as Comparative Example 2, a pressure-sensitive sensor in which two linear electrode spacers were arranged at a position of 16 mm from each end portion in the X direction of the electrode pair 80 toward the center portion was used. Further, as Comparative Example 3, a pressure-sensitive sensor in which two linear electrode spacers are arranged at positions substantially 11.5 mm from the respective end portions in the X direction of the electrode pair 80 toward the central portion is used. Further, as Comparative Example 4, three linear electrode spacers were arranged at the central portion in the X direction of the electrode pair 80 and at a position of 14.5 mm from the respective end portions in the X direction direction toward the central portion. A pressure sensitive sensor was used. Further, as Comparative Example 5, three linear electrode spacers were arranged at the central portion in the X direction of the electrode pair 80 and at a position of 8.5 mm from each end portion in the X direction direction toward the central portion. A pressure sensitive sensor was used.

  When the above experiment was carried out, the results shown in FIGS. 21 and 22 were obtained. Here, FIG. 21 is a diagram showing a resistance value between the upper electrode 60 and the lower electrode 50 of the electrode pair 80 in the first to fourth embodiments, and FIG. 22 is an electrode in the first to fifth comparative examples. 7 is a diagram showing a resistance value between an upper electrode 60 and a lower electrode 50 of a pair 80. FIG.

  As shown in FIG. 21, it was found that the pressure sensors of Examples 1 to 4 exhibited resistance values from about 5000 kΩ to about 7000 kΩ. Specifically, the pressure-sensitive sensor of Example 2 exhibits the highest resistance value of about 6900 to about 7000 kΩ, and then both of the pressure-sensitive sensors of Example 1 and Example 3 exhibit a high resistance value exceeding about 5000 kΩ. I understood. That is, it has been found that the resistance value is generally high without depending on the number of electrode spacers 90. On the other hand, as shown in FIG. 22, the pressure sensors of Comparative Examples 1 to 5 show resistance values of 0.8 kΩ to 10 kΩ, and extremely low resistance values (specifically, compared to Examples 1 to 4). Only 3 digits).

  Based on the above results, a linear electrode spacer 90 extending in the X direction corresponding to the circumferential direction R of the rim cross section (see FIG. 2) is provided in the vicinity of the center of the electrode pair 80 in the Y direction, thereby extending linearly in the Y direction. It has been found that the lower electrode 50 and the upper electrode 60 of the electrode pair 80 are significantly less likely to come into contact compared with the case where the electrode spacer 90 is provided.

  Although one embodiment of the present invention has been described so far, it is needless to say that the present invention is not limited to the above-described embodiment, and may be implemented in various forms within the scope of the technical idea. .

  It should be noted that the terms “lower” and “upper” used in this specification and other terms indicating positional relationships are used in the context of the illustrated embodiment and vary depending on the relative positional relationship of the apparatus. To do.

DESCRIPTION OF SYMBOLS 1 Grasp detection apparatus 10 Steering wheel 12 Rim 14 Hub 15 Spoke 16 Core 17 Buffer material 18 Skin 20A, 20B, 20C Pressure sensor 21A, 21B, 21C Connection part 22 Lower side board 22A Substrate piece 24 Substrate spacer 24A Substrate spacer piece 25 Through hole 26 Upper substrate 26A Substrate 30 Grip detection unit 32AJ, 32BJ detection circuit 34 Judgment unit 40 Connection wiring unit 41-46 Terminal 50 Lower electrode 50A Upper surface 51-55 Wiring (lower wiring)
60 Upper electrode 60A Lower surface 62 Wiring (upper wiring)
75 Electrode unit 80 Electrode pair 90, 91, 92 Electrode spacer 150, 160 Electrode portion 161, 162 Pressure sensitive ink 171, 172 Resist 181, 182 Adhesive material 181A, 182A Discontinuous portion 191 Upper substrate spacer 192 Lower substrate spacer 201 Upper Laminate 202 Lower laminate 300 Cushion material

Claims (12)

A sensor built into the rim of the steering wheel,
A lower substrate attachable to the rim;
An upper substrate disposed above the lower substrate;
At least one electrode pair comprising a lower electrode attached to the upper surface of the lower substrate and an upper electrode attached to the lower surface of the upper substrate so as to face the lower electrode, the upper electrode And at least one electrode pair in which at least one of the lower electrodes is constituted by a pressure-sensitive electrode;
A substrate spacer disposed around the at least one electrode pair, the substrate spacer disposed between the upper substrate and the lower substrate;
At least one electrode spacer disposed inside the substrate spacer such that the lower electrode and the upper electrode facing each other are separated from each other;
With
The length of the at least one electrode spacer in the first direction corresponding to the circumferential direction of the rim cross section perpendicular to the extending direction of the rim is longer than the length in the second direction corresponding to the extending direction of the rim. A sensor characterized by being formed as follows.   The sensor according to claim 1, wherein the at least one electrode spacer is formed such that a length in the first direction is longer than a maximum width in the second direction.   The at least one electrode spacer is formed so that the upper surface of the lower electrode or the lower surface of the upper electrode intersects with a straight line extending in the first direction at an angle of 0 degree to less than 45 degrees. The sensor according to claim 1 or 2, characterized by the above.   4. The sensor according to claim 1, wherein the at least one electrode spacer extends along the first direction. 5.   5. The at least one electrode spacer is provided at a central portion or in the vicinity of the central portion of the lower electrode or the upper electrode facing each other in the second direction. The sensor according to any one of the above.   The sensor according to any one of claims 1 to 5, wherein the at least one electrode pair includes a plurality of electrode pairs arranged along the second direction. An upper wiring connected to the upper electrode; and a lower wiring connected to the lower electrode;
The sensor according to claim 6, wherein at least one of the upper wiring and the lower wiring is connected to a plurality of electrode pairs arranged along the second direction through different channels. .   The sensor according to claim 1, wherein the at least one electrode pair includes a plurality of electrode pairs arranged along the first direction. An upper wiring connected to the upper electrode; and a lower wiring connected to the lower electrode;
The sensor according to claim 8, wherein at least one of the upper wiring and the lower wiring is connected to a plurality of electrode pairs arranged along the first direction through different channels. A sensor according to any one of claims 1 to 9 incorporated in a rim of a steering wheel;
The driver connects the rim based on the electrical connection state between the upper electrode of the sensor and the lower electrode opposite to the upper electrode, which is electrically connected to the upper electrode and the lower electrode of the sensor. A grip detection unit for detecting gripping;
A gripping detection device comprising:   The grip detection device according to claim 10, further comprising a cushion material provided between an outer peripheral surface of the core of the rim and a lower surface of the lower electrode.   The grip detection device according to claim 11, wherein the cushion material is made of urethane.

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