JP2019091578A - Capacitance sensor and steering - Google Patents

Abstract

To provide a capacitance sensor capable of improving accuracy for determining contact or proximity, and also to provide a steering having this capacitance sensor.SOLUTION: A capacitance sensor 30 includes: a dielectric body 34; a sensor electrode 32; and a conductor 36. The sensor electrode 32 is arranged and installed on one surface of the dielectric body 34 and creates capacitance between an object (hand 50) in contact with or in proximity to the other surface of the dielectric body 34. The conductor 36 is arranged and installed on the other surface portion of the dielectric body 34 in opposite to the sensor electrode 32. Compared to an area S1 of an opposing face 36A on one end side of the conductor 36 near the sensor electrode 32, an area S2 of an opposing face 36B on the other end side of the conductor 36 far from the sensor electrode 32 is configured smaller. This conductor 36 is brought into a floated state.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a capacitance sensor and a steering, and more particularly, to a capacitance sensor disposed in the steering and a technique effectively applied to a steering having the capacitance sensor.

  Patent Document 1 below discloses a capacitive touch sensor. The capacitive touch sensor includes the front panel of the electronic device, and a plurality of detection electrodes disposed with the air vent portion interposed in the detection layer on the back surface of the front panel. In the capacitive touch sensor, a voltage is applied to the detection electrode, and a change in capacitance generated between the finger in contact with the front panel surface and the detection electrode is detected. The detected capacitance is compared with a threshold, and when the capacitance is larger than the threshold, it is determined that the finger is in contact with the front panel surface (touch determination).

In the above-described capacitive touch sensor, for example, it may not be possible to distinguish between the case where a finger with a small area contacts the front panel surface and the case where a hand with a large area approaches the front panel surface.
For example, when the capacitive touch sensor is applied to an automatic driving system of a vehicle such as a car and used as a sensor for switching between the automatic driving mode and the manual driving mode, Accuracy is required to determine proximity.

JP, 2014-186403, A

  SUMMARY OF THE INVENTION The present invention provides a capacitance sensor capable of improving the accuracy of determining contact or proximity in consideration of the above fact, and a steering having the capacitance sensor.

  A capacitance sensor according to a first embodiment of the present invention comprises: a dielectric; and an electrostatic member disposed on one surface of the dielectric and in contact with or in proximity to the other surface facing the one surface of the dielectric. The sensor electrode for generating a capacitance, and the other surface portion of the dielectric opposite to the sensor electrode, is disposed on the other surface portion of the dielectric, and is opposed to the other end far from the sensor electrode A small area of the surface, and an electrically floating conductor.

  The capacitive sensor comprises a dielectric and a sensor electrode. The sensor electrode is disposed on one surface of the dielectric to generate capacitance between an object in contact with or in proximity to the other surface opposite to the one surface of the dielectric. The object is, for example, a human hand, a finger or the like.

Here, the capacitance sensor further includes a conductor. The conductor is disposed on the other surface portion of the dielectric opposite to the sensor electrode, and the area of the opposing surface on the other end side of the conductor remote from the sensor electrode of the conductor is compared to the area of the opposing surface on the one end side near the sensor electrode Is small. This conductor is electrically floating.
Therefore, when the object contacts the conductor, the conductor has the same potential as the object, and the area between the opposing surface on the other end of the conductor is larger than the area between the opposing surface on the one end of the conductor and the sensor electrode. Capacitance can be generated. On the other hand, when the object approaches the conductor, the electrostatic capacitance between the sensor electrode and the opposing surface at one end of the conductor, and the electrostatic capacitance between the opposing surface at the other end of the conductor and the object Capacity can be generated. Since the capacitance at the time of contact is larger and the capacitance at the time of proximity is smaller and the capacitance difference is enlarged, it is possible to improve the accuracy of the determination of whether the object is in contact or in proximity. it can.

  A capacitance sensor according to a second aspect of the present invention is the capacitance sensor according to the first aspect, wherein the detection portion connected to the sensor electrode and detecting the capacitance, and the static electricity detected by the detection portion And a determination unit that compares the capacitance with a threshold and determines the magnitude of the capacitance with respect to the threshold to determine whether it is a touch or a proximity.

The capacitance sensor according to the second embodiment further includes a detection unit and a determination unit. The detection unit is connected to the sensor electrode and detects the capacitance. The determination unit compares the capacitance detected by the detection unit with a threshold, determines the magnitude of the capacitance with respect to the threshold, and determines whether it is a touch or a proximity.
Therefore, the capacitance increased by the contact is compared with the threshold to determine the magnitude of the capacitance with respect to the threshold, and the capacitance decreased by the proximity is compared with the threshold with the magnitude of the capacitance with respect to the threshold Is determined. Therefore, it is possible to improve the accuracy of determining contact or proximity.

  A steering according to a third embodiment of the present invention includes a grip portion disposed around the steering axis, a dielectric provided on the grip portion along the steering axis, and an inner surface of the dielectric along the steering axis. A sensor electrode for generating a capacitance between an occupant in contact with or in proximity to the inner surface facing the dielectric and an outer surface facing the dielectric, and a sensor electrode provided on the outer surface portion of the dielectric facing the sensor electrode And the capacitance sensor having a conductor which is electrically floated, wherein the area of the opposing surface farthest from the sensor electrode is smaller than the area of the opposing surface near the sensor electrode, Have.

  The steering according to the third embodiment comprises a grip and a capacitance sensor. The gripping portion is disposed around the steering axis. The capacitive sensor comprises a dielectric and a sensor electrode. A dielectric is provided about the steering axis. The sensor electrode is disposed on the inner surface of the dielectric along the steering axis and generates capacitance between an occupant contacting or in close proximity to the outer surface facing the inner surface of the dielectric.

Here, the capacitance sensor further includes a conductor. A conductor is disposed on the outer surface portion of the dielectric opposite the sensor electrode. The area of the opposing surface on the other end side far from the sensor electrode of the conductor is smaller than the area of the opposing surface on the one end side closer to the sensor electrode of the conductor. The conductor is then electrically floated.
Therefore, when the occupant comes in contact with the conductor, the conductor is at the same potential as the occupant, and an electrostatic capacitance can be generated between the opposing surface on one end side of the conductor and the sensor electrode. On the other hand, when the occupant approaches the conductor, the capacitance between the sensor electrode and the opposing surface on one end of the conductor and the capacitance between the opposing surface on the other end of the conductor and the occupant are smaller than that. And can produce a capacitance that includes The capacitance at the time of contact is made larger, the capacitance at the time of proximity is made smaller, and the capacitance difference is enlarged. Therefore, it is possible to improve the accuracy of the determination of whether the occupant is in contact or in proximity.

  According to the present invention, it is possible to provide a capacitance sensor capable of improving the accuracy of determining contact or proximity, and a steering having the capacitance sensor.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram of the electrostatic capacitance sensor which concerns on 1st Embodiment of this invention, and the steering equipped with this electrostatic capacitance sensor. FIG. 2 is a cross-sectional view of the steering shown in FIG. 1 taken along the line A-A and viewed in the direction indicated by the arrows. It is the expansion schematic block diagram to which the code | symbol B part of the steering shown by FIG. 1 was expanded. (A) is an enlarged plan view enlarging the main part of the capacitance sensor shown in FIG. 3, (B) is an enlarged sectional view of the main part shown in (A) (cut along line C-C of (A) And the enlarged sectional view). (A) is an enlarged sectional view of the principal part of the capacitance sensor shown in FIG. 4 (B) in the contact state of an object (passenger), and (B) is a principal part in the proximity state of the object (A) FIG. 6 is an enlarged sectional view corresponding to FIG. (A) is an enlarged cross-sectional view corresponding to FIG. 5 (A) of a capacitance sensor according to a second embodiment of the present invention, (B) is a capacitance sensor according to a modification of the second embodiment It is an expanded sectional view corresponding to Drawing 5 (A).

First Embodiment
Hereinafter, a capacitance sensor according to a first embodiment of the present invention and steering of a vehicle having the capacitance sensor will be described with reference to FIGS. 1 to 5. Here, as appropriate, the arrow FR shown indicates the forward direction of the vehicle, the arrow W indicates the width direction of the vehicle, and the arrow UP further indicates the upward direction of the vehicle. The application direction of the capacitance sensor and the steering is not limited to the present embodiment.

(Configuration of steering)
As shown in FIG. 1, a steering 10 as a steering wheel constituting a steering device (steering device) is disposed in a vehicle (not shown). The steering 10 is provided with a core 24. The cored bar 24 is formed, for example, by casting an alloy material. For example, a magnesium alloy material is used as the alloy material.

The core 24 is provided with a boss 14 at its center. The boss portion 14 is fixed to a steering shaft (steering shaft) 12 which constitutes a steering device of the vehicle. A rim cored bar portion 24A that constitutes a part of the cored bar 24 is provided around the boss portion 14 and around the boss portion 14. The rim cored bar portion 24A is installed facing the driver's seat, and an occupant seated in the driver's seat (may be described as an "object" in the explanation of the capacitance sensor) is formed substantially annularly as viewed from the front. It is done.
Further, as shown in FIG. 2, the cross section of the rim cored bar portion 24A cut along the axial direction of the steering shaft 12 is bifurcated and has a C-shape which is opened on the vehicle front side of the steering shaft 12 It is done. In the present embodiment, the iron weight 22 constituting the cored bar 24 is fitted in the rim cored bar portion 24A. When the occupant is viewed from the front, the shape of the weight 22 is substantially annular.

  As shown in FIG. 1, a plurality of spokes 16 that constitute the core 24 are provided between the boss 14 and the rim core 24A. The spoke portion 16 is configured to connect the boss portion 14 and the rim cored bar portion 24A, and the boss portion 14, the spoke portion 16 and the rim cored bar portion 24A are integrally formed. That is, when the rim cored bar portion 24A is rotated around the steering shaft 12, the boss portion 14 is rotated via the spoke portion 16 and the steering shaft 12 fixed to the boss portion 14 is rotated about that axis It is assumed.

  The right half semi-annular portion of the rim core 24A disposed along the circumference of the steering shaft 12 as viewed from the front of the occupant is a grip 20 (R ). Similarly, the left semicircular ring-shaped portion of the rim cored bar portion 24A is a holding portion 20 (L) which can be held by the left hand. As shown in FIG. 2, in each of the gripping portions 20 (R) and 20 (L), the circumferential region of the rim cored bar portion 24A centered on the rim cored bar portion 24A serves as a core material. Is covered by the soft member 26 of FIG. The soft member 26 is made of a synthetic resin material that is softer than the rim cored metal part 20, in this case a hard urethane resin material.

(Configuration of capacitance sensor)
In the steering 10 according to the present embodiment, as shown in FIG. 1, two (divided into two) capacitance sensors 30 (R) and capacitance sensors 30 (L) are disposed. . In the present embodiment, the two capacitance sensors 30 (R) and the capacitance sensor 30 (L) may be described as one “capacitance sensor 30”.
More specifically, one capacitance sensor 30 (R) is disposed along the periphery of the steering shaft 12 in the right grip 20 (R). The other capacitive sensor 30 (L) is disposed along the periphery of the steering shaft 12 in the left grip 20 (L). When divided into a plurality of capacitance sensors 30 (R) and capacitance sensors 30 (L), when the occupant grips the right gripping portion 20 (R), the left gripping portion 20 (L) is gripped Capacitance at each time can be detected, and the accuracy of the detection position can be improved.

The capacitance sensor 30 (L) on the left side is configured to include a dielectric 34 and a sensor electrode 32 (L) as shown in FIG. 1, FIG. 2, FIG. 3 and FIG. There is.
A dielectric 34 is provided along the periphery of the steering shaft 12 in the gripping portion 20 (L), and is further provided to cover all of the circumferential direction centering on the rim cored portion 24A of the gripping portion 20 (L) It is formed of ten decorative materials. Here, as the dielectric 34, a leather material (outer leather material) which is not slippery at the time of operation, has a good touch, and is excellent in decoration with a high-class feeling is used. As shown in FIG. 2 and FIG. 3, the dielectric 34 covers all of the circumferential direction centering on the rim core 24A of the grip portion 20 (L), and at the inside of the annular rim core 24A. And the sewing thread 34A is used.
Moreover, as a leather material of the dielectric 34, if it has a function as a dielectric, either real leather or synthetic leather can be used. Furthermore, as the dielectric 34, a resin material, a resin material having at least a surface layer decorated, or the like can be used.

  The sensor electrode 32 (L) is disposed on the inner surface of the grip portion 20 (L), which is one surface of the dielectric 34 and on the rim cored portion 24A side. Specifically, the sensor electrode 32 (L) is wound along a circumferential surface around the rim cored bar portion 24A of the soft member 26. Here, the sensor electrode 32 (L) has a conductive cloth, for example, a conductive cloth in which a polyester fiber is nickel-plated, and further, an acrylic conductive adhesive is applied to one side of the conductive cloth. Conductive cloth can be used practically.

On the other hand, the capacitance sensor 30 (R) on the right side is configured to include the dielectric 34 and the sensor electrode 32 (R) as shown in FIG. 1, FIG. 3 and FIG. 4 (B). The structure of the capacitance sensor 30 (R) is the same as the structure of the capacitance sensor 30 (L).
That is, the dielectric 34 is provided on the grip 20 (R) along the periphery of the steering shaft 12 and is further provided to cover all of the circumferential direction centering on the rim core 24A of the grip 20 (R). It is formed of the decorative material. As the decorative material, for example, a leather material of the same material formed integrally with or integrally with the decorative material as the dielectric 34 disposed in the grip portion 20 (R) is used.
The sensor electrode 32 (R) is disposed on the inner surface of the rim cored bar portion 24A which is one surface of the dielectric 34 in the grip portion 20 (R). Similar to the sensor electrode 32 (L), the sensor electrode 32 (R) is wound along the circumferential surface of the soft member 26 and is formed using the same material.
The sensor electrode 32 (L) and the sensor electrode 32 (R) may be collectively referred to simply as “sensor electrode 32”.

  As described above, since the capacitance sensor 30 (R) and the capacitance sensor 30 (L) are divided into two, as shown in FIGS. 1 and 3, the sensor electrode 32 (R) is a separation region The sensor electrode 32 (L) is disposed via the separation area 32A and the separation area 32B. Each of the separation region 32A and the separation region 32B is a portion that electrically insulates the sensor electrode 32 (R) and the sensor electrode 32 (L) (no current flows). In the non-operating state of the steering 10 in which the front tire of the vehicle is directed straight ahead, the separation area 32A is located at the top of the steering 10, and the separation area 32B is located at the bottom of the steering 10.

  As shown in FIG. 3, FIG. 4 (A) and FIG. 4 (B), in the capacitance sensor 30 (R) of the capacitance sensor 30, the dielectric 34 is opposed to the sensor electrode 32 (R). A conductor 36 is disposed on the outer surface portion. A plurality of conductors 36 are arranged in the grip 20 (R) at regular intervals along the circumference of the steering shaft 12 and at regular intervals in the circumferential direction around the rim core 24A. There are multiple units. Here, as shown in FIGS. 3 and 4A, the conductors 36 are regularly arranged in a matrix. The conductors 36 may be arranged in a staggered manner.

As shown in FIG. 4B, the area S1 of the facing surface 36A on one end side of the conductor 36 near the sensor electrode 32 (R) is far from the sensor electrode 32 (R) and on the other end side of the conductor 36 The configuration is larger than the area S2 of the facing surface 36B. In other words, the area S2 of the facing surface 36B is smaller than the area S1 of the facing surface 36A. Here, the conductor 36 is in the shape of a truncated cone. As the conductor 36, a metal material such as an iron material, an aluminum material, or a titanium material, or an alloy material having this metal material as a main composition can be practically used. In addition, for the conductor 36, a resin material containing carbon fiber can also be practically used, in addition to the decorating property.
The conductor 36 is not limited to the truncated cone shape, and may be, for example, an elliptical frustum shape, or a polygonal frustum shape having a number of angles greater than or equal to three.

Further, in the present embodiment, as shown in FIG. 4B, the first dielectric 34A provided on the side of the sensor electrode 32 (R) and the sensor electrode 32 (R) are on the opposite side. The conductor 36 is embedded in the second dielectric 34B in a laminated structure with the provided second dielectric 34B. The conductor 36 is press-fit into a through hole previously formed in the second dielectric 34B from the sensor electrode 32 (R) side to the opposite side. The opposing surface 36B of the conductor 36 is exposed from the surface of the second dielectric 34B.
Here, the facing surface 36B is flush with the surface of the second dielectric 34B, but may slightly protrude from the surface of the second dielectric 34B or slightly enter the inside of the second dielectric 34B. It may be
The conductor 36 is electrically floated, and the occupant is at ground potential. Therefore, when the occupant's hand or finger comes in contact with the conductor 36, the conductor 36 is brought to the same ground potential.

  Similarly, in the capacitance sensor 30 (L) of the capacitance sensor 30, a conductor 36 is disposed on the outer surface portion of the dielectric 34 so as to face the sensor electrode 32 (L). The conductors 36 are regularly arranged in a matrix in the grips 20 (L). The conductor 36 has the same configuration as the conductor 36 disposed in the capacitance sensor 30 (R).

As shown in FIG. 1, the sensor electrode 32 (L) of the capacitance sensor 30 (L) on the left side is connected to the first detection unit 42, and the first detection unit 42 is connected to the determination unit 40. The sensor electrode 32 (R) of the capacitance sensor 30 (R) on the right side is connected to the second detection unit 44, and the second detection unit 44 is connected to the determination unit 40.
The first detection unit 42 applies a constant voltage as a detection voltage to the sensor electrode 32 (L) of the capacitance sensor 30 (L) in the grip unit 20 (L). A change in capacitance that occurs when touching or approaching is detected as a change in sensed voltage. Similarly, in the second detection unit 44, a constant voltage serving as a detection voltage is applied to the sensor electrode 32 (R) of the capacitance sensor 30 (R) in the grip unit 20 (R), and the hand 50 contacts the dielectric 34 A change in capacitance that occurs when touching or approaching is detected as a change in sensed voltage.
In the determination unit 40, the capacitances detected by each of the first detection unit 42 and the second detection unit 44 are compared with the threshold value, and the magnitude of the capacitance with respect to the threshold value is determined. Here, as the threshold, a touch threshold for determining whether touch or non-contact (touch or non-touch) and a proximity threshold for determining whether close or non-close are set in advance.
When the capacitance is larger than the contact threshold, the determination unit 40 determines that the hand has touched the grip unit 20 (L) or the grip unit 20 (R), for example (touch determination). Conversely, when the capacitance is smaller than the touch threshold, the determination unit 40 determines that the hand is not touched by the grip unit 20 (L) or the grip unit 20 (R) (a non-touch determination). ).
Furthermore, when the capacitance is larger than the proximity threshold, the determination unit 40 determines, for example, that the hand is in proximity to the holding unit 20 (L) or the holding unit 20 (R). Conversely, if the capacitance is smaller than the proximity threshold, the determination unit 40 determines that the hand is not in proximity to the grip 20 (L) or the grip 20 (R).
Each of the contact information and the proximity information is transmitted to, for example, an automatic driving system (not shown) and used for switching between the automatic driving mode and the manual driving mode.

(Operation and effect of the present embodiment)
Capacitance sensor 30 according to the present embodiment includes dielectric 34 and sensor electrode 32 as shown in FIGS. 1 to 3. The sensor electrode 32 is disposed on one surface (inner surface) of the dielectric 34, and is electrostatically interposed between the occupant's hand 50 (or finger) as an object contacting the other surface (outer surface) of the dielectric 34. Produce capacity.

  Here, as shown in FIGS. 4A and 4B, the capacitance sensor 30 further includes a conductor. The conductor 36 is disposed on the other surface portion of the dielectric 34 so as to face the sensor electrode 32. The area S2 of the opposing surface 36B far from the sensor electrode 32 is smaller than the area S1 of the opposing surface 36A closer to the sensor electrode 32 of the conductor 36 on the one end side. Then, the conductor 36 is electrically floated.

As shown in FIG. 5A, when the hand 50 (or a finger) contacts the conductor 36, the conductor 36 has the same potential as the hand 50. Since the hand 50 is at the ground potential, the conductor 36 is at the ground potential. Then, a capacitance C1 can be generated between the sensor electrode 32 and the facing surface 36A on one end side of the conductor 36. The total capacitance Ct when the hand 50 contacts the conductor 36 is represented by the following formula (1), where N (N is an integer of 1 or more) the number of the conductors 36 with which the hand 50 contacts.
Ct = N × C1 + C3 (1)
Here, C3 is a capacitance generated between the sensor electrode 32 and the hand 50 in a region where the conductor 36 is not disposed. Also, capacitance C is generally expressed by the following equation (2), where ε is the dielectric constant, S is the electrode area, and d is the distance between the electrodes (the thickness of the dielectric), as in a flat plate capacitor. Ru.
C = εS / d (2)

On the other hand, as shown in FIG. 5B, when the hand 50 approaches the conductor 36, the capacitance C1 between the opposing surface 36A on one end side of the conductor 36 and the sensor electrode 32, and air as a dielectric A capacitance C2 can be generated between the hand 50 and the opposing surface 36B on the other end side of the conductor 36, which is smaller than the capacitance C1. The total capacitance Cn when the hand 50 approaches the conductor 36 is expressed by the following equation (3).
Cn = N × (C1 × C2) / (C1 + C2) + C3 (3)
Here, if the area S2 of the opposing surface 36B of the conductor 36 is set sufficiently smaller than the area S1 of the opposing surface 36A (S1 >> S2), the electrostatic capacitance C2 is sufficiently smaller than the electrostatic capacitance C1. It becomes smaller (C1 >> C2). Thereby, the said Formula (3) can be rewritten to following formula (4).
Cn ≒ N × C2 + C3 (4)
Therefore, the electrostatic capacitance Ct at the time of contact is larger, the electrostatic capacitance Cn at the time of proximity is smaller, the electrostatic capacity difference is enlarged, and the accuracy of the determination of whether the hand 50 is in contact or in proximity is improved. It can be done.

Further, as shown in FIG. 1, the capacitance sensor 30 according to the present embodiment further includes a first detection unit 42, a second detection unit 44, and a determination unit 40. The first detection unit 42 is connected to the sensor electrode 32 (L), and detects the capacitance Ct or the capacitance Cn. Similarly, the second detection unit 44 is connected to the sensor electrode 32 (R) and detects the capacitance Ct or the capacitance Cn.
The determination unit 40 compares the capacitance Ct detected by the first detection unit 42 with a contact threshold value for determining contact, and determines whether the capacitance Ct is larger or smaller than the contact threshold value to determine whether the contact or non-contact is made. . Further, the determination unit 40 compares the capacitance Cn detected by the first detection unit 42 with the proximity threshold for determining proximity, determines the magnitude of the capacitance Cn with respect to the proximity threshold, and determines whether it is proximity or non-proximity judge.
On the other hand, the determination unit 40 compares the capacitance Ct detected by the second detection unit 44 with the contact threshold, determines the magnitude of the capacitance Ct with respect to the contact threshold, and determines whether it is contact or noncontact. Further, the determination unit 40 compares the capacitance Cn detected by the second detection unit 44 with the proximity threshold, determines the magnitude of the capacitance Cn with respect to the proximity threshold, and determines whether proximity or non-proximity.
Therefore, the capacitance Ct increased by the touch is compared with the touch threshold to determine the magnitude of the capacitance with respect to the touch threshold, and the capacitance Cn decreased by the proximity is compared with the proximity threshold and the proximity threshold is determined. The magnitude of the capacitance is determined. Therefore, it is possible to improve the accuracy of determining contact or proximity.

  Further, as shown in FIG. 1, the steering 10 according to the present embodiment includes a grip 20 and a capacitance sensor 30. The grip portion 20 is disposed around the steering shaft 12. The capacitance sensor 30 includes a dielectric 34 and a sensor electrode 32 as shown in FIGS. 1 to 3. A dielectric 34 is provided around the steering axis 12. The sensor electrode 32 is disposed on the inner surface of the dielectric 34 along the steering axis 12 and between the occupant's hand 50 (or finger) in contact with or close to the outer surface facing the inner surface of the dielectric 34. To produce a capacitance Ct or a capacitance Cn.

Here, the capacitance sensor further includes a conductor 36 as shown in FIG. 3, FIG. 4 (A) and FIG. 4 (B). Conductor 36 is disposed on the outer surface of dielectric 34 opposite sensor electrode 32. Further, the conductor 36 is electrically floated as compared with the area S1 of the opposing surface 36A on one end side near the sensor electrode 32, the area S2 of the opposing surface 36B on the other side far from the sensor electrode 32 is smaller. .
Therefore, as shown in FIG. 5A, when the hand 50 contacts the conductor 36, the conductor 36 becomes the same potential as the hand 50, and the opposing surface 36A of one end side of the conductor 36 and the sensor electrode 32 Capacitance C1 can be generated between them. On the other hand, when the hand 50 approaches the conductor 36, the electrostatic capacitance C1 between the sensor electrode 32 and the opposing surface 36A on one end side of the conductor 36 and the opposing surface 36B on the other side of the conductor 36 are smaller than that. A capacitance C2 can be generated which includes the capacitance C2 between the hand 50 and the hand 50. Since the capacitance Ct at the time of contact is made larger including the capacitance C1, and the capacitance Cn at the time of proximity is made smaller including the capacitance C2, the capacitance difference is expanded, The accuracy of the determination as to whether the hand 50 is in contact or in proximity can be improved.
In such a steering 10, for example, it is possible to improve the accuracy of switching between the automatic driving mode and the manual driving mode in the automatic driving system.

Second Embodiment
A capacitance sensor 30 and a steering wheel 10 according to a second embodiment of the present invention will be described with reference to FIG. In the present embodiment, the same components as or the components substantially the same as the components of the capacitance sensor 30 according to the first embodiment are denoted by the same reference numerals, and the redundant description will be omitted.

As shown in FIG. 6A, in the capacitance sensor 30 according to the present embodiment, the side surface of the conductor 36 is formed in a curved shape that protrudes to the periphery. Similar to the conductor 36 of the capacitance sensor 30 according to the first embodiment, the area S1 of the opposing surface 36A at one end of the conductor 36 is larger than the area S2 of the opposing surface 36B at the other end of the conductor 36 It is assumed.
The other configurations of the capacitance sensor 30 and the steering 10 are the same as the configurations of the capacitance sensor 30 and the steering 10 according to the first embodiment.
In the electrostatic capacitance sensor 30 and the steering wheel 10 according to the present embodiment, the same operational effects as those obtained by the electrostatic capacitance sensor 30 and the steering wheel 10 according to the first embodiment can be obtained.

  In the capacitance sensor 30 according to the modification of the present embodiment, as shown in FIG. 6B, the side surface of the conductor 36 is formed in a curved shape that is recessed inward. The other configurations of the capacitance sensor 30 and the steering 10 are the same as the configurations of the capacitance sensor 30 and the steering 10 according to the first embodiment.

[Supplementary explanation of the above embodiment]
The present invention is not limited to the above embodiment, and can be modified as follows without departing from the scope of the invention.
For example, in the above embodiment, the capacitance sensor 30 includes two capacitance sensors 30 (L) and a capacitance sensor 30 (R). In the present invention, one or more capacitance sensors 30 may be provided on the steering 10.
Moreover, although the said embodiment illustrated ring-shaped steering 10, this invention may be rectangular-shaped steering.

  DESCRIPTION OF SYMBOLS 10 ... Steering, 12 ... Steering shaft, 20 (L), 20 (R) ... Gripping part 30, 30, 30 (L), 30 (R) ... Capacitance sensor, 32 (L), 32 (R) ... Sensor Electrodes 34: dielectrics 36: conductors 36A, 36B: facing surfaces 40: judgment unit 42: first detection unit 44: second detection unit

Claims (3)

With dielectrics,
A sensor electrode disposed on one surface of the dielectric and generating capacitance between an object contacting or in proximity to the other surface facing the one surface of the dielectric;
It is disposed on the other surface portion of the dielectric opposite to the sensor electrode, and the area of the opposing surface on the other side far from the sensor electrode is smaller than the area of the opposing surface on the one end side closer to the sensor electrode , Electrically floating conductors,
Capacitance sensor equipped with A detection unit connected to the sensor electrode for detecting a capacitance;
A determination unit that compares the capacitance detected by the detection unit with a threshold, determines the magnitude of the capacitance with respect to the threshold, and determines whether it is a touch or a proximity;
The capacitance sensor according to claim 1, further comprising: A grip disposed around the steering axis,
A dielectric provided on the grip portion along the periphery of the steering axis,
A sensor electrode disposed on the inner surface of the dielectric around the steering axis and generating capacitance between an occupant contacting or in proximity to the outer surface facing the inner surface of the dielectric; It is disposed on the outer surface portion of the dielectric opposite to the sensor electrode, and the area of the opposing surface on the other end side far from the sensor electrode is smaller than the area of the opposing surface on the one end side closer to the sensor electrode A capacitance sensor having a conductor that is electrically floated;
Steering equipped.