Sensing device and steering wheel

Abstract

A sensing device and a steering wheel solve a problem of abnormal operation of a touch sensor or a heater due to short circuit of a circuit of the touch sensor and a circuit of the heater. The sensing device has a load portion having a conductive portion and a base material portion, a cover portion, a sensor circuit that detects an object in contact with the cover portion, and a heater circuit that heats the conductive portion, the sensor circuit has a sensor wiring connection portion electrically connected to the conductive portion, the heater circuit has a positive electrode wiring connection portion and a negative electrode wiring connection portion supported to the base material portion in the load portion, the conductive portion is heated between the positive electrode wiring connection portion and the negative electrode wiring connection portion, and the sensor wiring connection portion, the positive electrode wiring connection portion, and the negative electrode wiring connection portion are in contact with a layer representing the conductive portion and are separately provided from each other in a cross section representing a stacked structure of the conductive portion and the cover portion.

Description

Technical Field

[0001] This invention relates to a sensing device and a steering wheel. Background Technology

[0002] Regarding steering wheels, as described in Patent Document 1, a steering wheel with a touch sensor for detecting the driver's grip and a heater for heating the wheel rim is known. In the cross-section of the wheel rim of Patent Document 1, the layers of the touch sensor and the heater are laminated via an insulating material. Furthermore, the layer of the touch sensor includes a layer constituting electrodes for detecting grip. The layer of the heater includes a layer constituting a heating element. For the aforementioned layers, metallic materials are sometimes used.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2025-27750

[0004] The touch sensor layer or the heater layer may deform due to pressure generated by the driver gripping the wheel rim. Furthermore, if the touch sensor layer or the heater layer contains metallic materials, it may undergo plastic deformation and not return to its original shape. In this case, since the deformed component penetrates the insulating material that insulates between the touch sensor layer and the heater layer, contact may occur between them.

[0005] As a result, a short circuit in the circuitry of the touch sensor and the heater may cause the touch sensor or heater to malfunction. Summary of the Invention

[0006] This invention can be implemented in the following ways.

[0007] (1) According to a first aspect of the present invention, a sensing device is provided. The sensing device includes: a load portion having a conductive portion and a substrate portion, the conductive portion being conductive, the substrate portion being configured to support the conductive portion and being covered by the conductive portion; a cover portion being stacked to cover the conductive portion; a sensor circuit that detects an object in contact with the cover portion; and a heater circuit that heats the conductive portion, the sensor circuit detecting the object based on changes in the state of the conductive portion, having a sensor wiring connection portion electrically connected to the conductive portion and supported in the load portion on the substrate portion, the heater circuit having a positive wiring connection portion and a negative wiring connection portion electrically connected to the conductive portion and supported in the load portion on the substrate portion, heating the conductive portion between the positive wiring connection portion and the negative wiring connection portion, the sensor wiring connection portion, the positive wiring connection portion, and the negative wiring connection portion being in contact with the layer representing the conductive portion in a cross-section showing the stacked structure of the conductive portion and the cover portion, and being disposed separately from each other.

[0008] In this configuration, the sensor wiring connection, positive electrode wiring connection, and negative electrode wiring connection are in contact with the layer representing the conductive portion, but are arranged separately from each other. Therefore, short circuits caused by direct contact between the connections are less likely to occur. By configuring it in this way, even if any of the sensor wiring connection, positive electrode wiring connection, and negative electrode wiring connection deforms when pressure is applied to the conductive portion by an object in contact with the cover, mutual contact can be suppressed. That is, the sensing device can suppress short circuits in the sensor circuit and the heater circuit.

[0009] (2) The sensing device described above may further include: a switching circuit that switches the operation of the sensor circuit and the operation of the heater circuit; and a control circuit that controls the sensing device. The sensor circuit is also capable of disconnecting the connection with the conductive part. The control circuit switches the operation of the sensor circuit and the operation of the heater circuit through the switching circuit. During the operation of the heater circuit, the connection between the sensor circuit and the conductive part is disconnected through the sensor circuit.

[0010] By configuring it in this way, the sensor circuit and the heater circuit will not operate simultaneously. Furthermore, the sensor circuit will be disconnected from the conductive part during the operation of the heater circuit. Typically, the voltage applied to heat the conductive part is higher than the voltage applied to the conductive part for detection purposes. Therefore, during the operation of the heater circuit, if the sensor circuit is connected to the conductive part, current may flow from the heater circuit to the sensor circuit. However, by disconnecting the current flow from the heater circuit to the sensor circuit, the sensing device can suppress malfunctions caused by this current inflow.

[0011] (3) The sensing device described above may be a rectangular shape when the substrate is unfolded into a plane, the sensor wiring connection is provided along the short side of the substrate, the positive wiring connection is provided along one long side of the substrate, and the negative wiring connection is provided along the other long side of the substrate.

[0012] In this configuration, the distance between the positive and negative wiring connections is shorter compared to the case where they are arranged along the short side. When the conductive part is heated by the heater circuit, the amount of heat generated varies depending on the resistance of the conductive part. The resistance of the conductive part depends on the distance between the positive and negative wiring connections. That is, the resistance of the conductive part is smaller compared to the case where the positive and negative wiring connections are arranged along the short side. The smaller the resistance, the higher the possibility that the sensing device can reduce the applied voltage. Therefore, it is easier to design the heater circuit in the sensing device.

[0013] (4) The sensing device described above may be provided separately from the two ends of the short side where the positive electrode wiring connection and the negative electrode wiring connection are located when the substrate is unfolded into a plane.

[0014] By designing it in this way, the sensor wiring connection portion located along the short side of the substrate and the positive and negative wiring connections located along the long side of the substrate are less likely to come into contact. Therefore, the sensing device can suppress contact between the sensor wiring connection portion and the positive or negative wiring connection portion.

[0015] (5) In the sensing device of the above manner, the control circuit may further include: a switching mode that alternately switches the operation of the heater circuit and the operation of the sensor circuit; and a sensor operating mode that only enables the sensor circuit in the heater circuit and the sensor circuit to operate, and switches the switching mode and the sensor operating mode according to the user's instruction.

[0016] By configuring it in this way, the control circuit can detect objects in contact with the covering part without heating the conductive part, based on the sensor's operating mode. Furthermore, the control circuit can also achieve the same detection function and heat the conductive part by switching modes. Therefore, compared to methods that require either the sensor circuit or the heater circuit to operate, the sensing device offers greater convenience.

[0017] (6) According to a second aspect of the present invention, a steering wheel is provided. The steering wheel has: a rim held by a driver and having a metal core in its cross-section; and a sensing device having: a load portion having a conductive portion and a substrate portion, the conductive portion being conductive, the substrate portion being configured to support the conductive portion and being covered by the conductive portion; a cover portion being stacked to cover the conductive portion; a sensor circuit for detecting an object in contact with the cover portion; and a heater circuit for heating the conductive portion, the load portion and the cover portion being disposed on the rim to cover the metal core, the sensor circuit detecting the object according to a change in the state of the conductive portion, and having a sensor The sensor wiring connection is electrically connected to the conductive part and supported on the substrate part in the load part. The heater circuit has a positive wiring connection and a negative wiring connection, which are electrically connected to the conductive part and supported on the substrate part in the load part. The conductive part is heated between the positive wiring connection and the negative wiring connection. In a cross-section showing the laminated structure of the conductive part and the cover part, the sensor wiring connection, the positive wiring connection, and the negative wiring connection are in contact with the layer showing the conductive part and are disposed separately from each other.

[0018] In this configuration, the sensor wiring connection, positive wiring connection, and negative wiring connection are in contact with the layer representing the conductive parts, but are arranged separately from each other. Therefore, short circuits caused by direct contact between the connections are less likely to occur. By arranging it in this way, even if any of the sensor wiring connection, positive wiring connection, and negative wiring connection deforms when pressure is applied to the conductive parts by an object in contact with the cover, mutual contact can be suppressed. That is, the steering wheel can suppress short circuits in the sensor circuit and the heater circuit. Attached Figure Description

[0019] Figure 1 This is an explanatory diagram showing the schematic structure of the sensing device according to the first embodiment.

[0020] Figure 2 This is a cross-sectional view of the load section.

[0021] Figure 3This is an explanatory diagram showing the schematic structure of the sensing device according to the second embodiment.

[0022] Figure 4 This is an explanatory diagram showing the schematic structure of the sensing device according to the third embodiment.

[0023] Figure 5 This is an explanatory diagram of the steering wheel according to the fourth embodiment.

[0024] Figure 6 It is a cross-sectional view of the rim of the steering wheel. Detailed Implementation

[0025] A. Implementation Method 1: A-1. Structure of the sensing device: Figure 1 This is an explanatory diagram showing a schematic structure of the sensing device 10 according to the first embodiment. The sensing device 10 is applied to various objects. The sensing device 10 is capable of detecting contact with an object and warming the applied object. For example, the sensing device 10 is disposed on the rim 210 of the steering wheel 20. In this case, the sensing device 10 is capable of detecting the driver's grip on the rim 210 and warming the driver's hand via the rim 210. However, in addition to the steering wheel 20, the sensing device 10 can also be applied to car seats, center consoles, etc. Furthermore, in other embodiments, the application of the sensing device 10 to the steering wheel 20 is described in detail. Figure 5 The middle diagram shows the labels related to steering wheel 20.

[0026] The sensing device 10 has a load portion 110 that covers the contact area of ​​the detected object and functions as a heat source. The load portion 110 is used in a three-dimensional shape, not a planar shape, depending on the application. That is, the load portion 110 is sometimes three-dimensionally shaped to match the shape of the application object. For example, when the sensing device 10 is disposed on the rim 210 of the steering wheel 20, the substrate portion 112 is used in a curved cylindrical state. However, in the first embodiment, for ease of understanding, the description is based on the case where the load portion 110 is unfolded into a planar shape. Furthermore, when the load portion 110 is three-dimensionally shaped, the basic structure or function of the sensing device 10 is the same as when the load portion 110 is unfolded into a planar shape. Hereinafter, "the case where the load portion 110 is unfolded into a planar shape" and "the case where the substrate portion 112 is unfolded into a planar shape" have the same meaning.

[0027] The sensing device 10 includes a load section 110, a cover section 120, a sensor circuit 130, and a heater circuit 140. Furthermore, in Figure 1 In order to show the internal structure of the load section 110, only the outline of the cover section 120 covering the load section 110 is shown.

[0028] exist Figure 1 In order to illustrate the structure of the load unit 110, an orthogonal coordinate system of XYZ is defined. Figure 1 In this coordinate system, the X-axis is along the long side 112L of the substrate portion 112 of the load portion 110. The Y-axis is along the short side 112S of the substrate portion 112. The Z-axis is the thickness direction of the sensing device 10. That is, the Z-axis is the direction in which the structural elements of the load portion 110 are stacked. Furthermore, the orthogonal coordinate system is defined for the purpose of explaining the structure of the load portion 110 and is not used to define the position of the circuit portion 11, including the sensor circuit 130 and the heater circuit 140.

[0029] The load portion 110 functions as a heating element. Furthermore, the load portion 110 defines the range for detecting objects that come into contact with the cover portion 120. These functions will be explained in detail later. The load portion 110 includes a conductive portion 111 and a substrate portion 112.

[0030] Figure 2 This is a cross-sectional view of the load portion 110. The substrate portion 112 supports the conductive portion 111. Furthermore, the substrate portion 112 is configured to be covered by the conductive portion 111. More specifically, the substrate portion 112 has a rectangular shape when unfolded into a planar surface. Additionally, in... Figure 1 In the illustration, the substrate portion 112 is covered by the conductive portion 111 and the wiring connection portion described later, and therefore is not shown. However, in the illustrated case, the substrate portion 112 has the same rectangular shape. "Wiring connection portion" refers to the collective term for the sensor wiring connection portion 131, the positive electrode wiring connection portion 141, and the negative electrode wiring connection portion 142. Specifically, as... Figure 2 As shown, the substrate portion 112 is covered by the conductive portion 111 by laminating the conductive portion 111 over the entire surface of either the front or back side.

[0031] The substrate portion 112 is made of, for example, an insulating knitted material. The fibers constituting the knitted material are made of a soft, resinous material. For example, polyester fibers are used to constitute the knitted material. Because the substrate portion 112 is made of knitted material, it is both soft and elastic. As a result, the sensing device 10 can assemble the load portion 110 onto an application object with a curved or complex shape, such as the rim 210 of a steering wheel 20.

[0032] However, the fibers constituting the knitted material can be other fibers such as nylon fibers. Furthermore, the substrate 112 can also be a film material, fabric, or nonwoven fabric.

[0033] Furthermore, the conductive portion 111 is formed by coating one side of the substrate portion 112 with a conductive coating. When the substrate portion 112 is made of a knitted material, a portion of the conductive coating penetrates into the interior of the substrate portion 112. Therefore, the substrate portion 112 supports the conductive portion 111 with a portion of the conductive portion 111 permeated within it. In this specification, "the substrate portion 112 containing a portion of the conductive portion 111" also refers to the conductive portion 111 being laminated on the substrate portion 112. Furthermore, in the figures, for ease of understanding, the conductive portion 111 and the substrate portion 112 are illustrated in a state where the layers are separated.

[0034] The conductive portion 111 is conductive. As described above, the conductive portion 111 is formed on the substrate portion 112 by coating with a conductive paint. The conductive paint is, for example, a paint mixed with multilayer carbon nanotubes and polyester. Since this paint does not use metal-based particles, the conductive portion 111 can easily recover even if it is deformed due to pressure. Furthermore, when the conductive portion 111 includes a metal portion, the metal portion may become sharp due to deformation. The sharp metal portion penetrates the contacting structural element, thereby potentially coming into contact with other uncontacted structural elements. That is, the conductive portion 111 may short-circuit with other structural elements. However, when the conductive portion 111 does not include a metal portion, such a short circuit can be prevented.

[0035] However, conductive coatings can also use coatings containing metallic particles such as nickel or silver, or conductive carbon-based coatings other than multilayer carbon nanotubes.

[0036] Furthermore, the thickness of the conductive portion 111 varies depending on the number of coating applications or the amount of coating applied. The thickness of the conductive portion 111 affects its resistance value. Therefore, the greater the thickness of the conductive portion 111, the lower the resistance value. On the other hand, the smaller the thickness of the conductive portion 111, the higher the resistance value. In other words, the thickness of the conductive portion 111 is adjusted according to the required resistance value for the conductive portion 111. The required resistance value is adjusted according to the required heat generation. Therefore, the thickness of the conductive portion 111 is adjusted according to the required heat generation in the application of the sensing device 10.

[0037] Furthermore, by adjusting the resistance value of the conductive part 111, the detection sensitivity of the sensor circuit 130 is also adjusted. For example, when the conductive part 111 is used as an electrode in a capacitive touch sensor, the resistance value of the electrode affects the rate of charge charging and discharging. For example, the higher the resistance value of the electrode, the slower the rate of charge charging and discharging, thereby slowing down the rise or fall edge of the voltage. As a result, it becomes difficult to detect changes in capacitance caused by contact with an object. Consequently, the detection sensitivity decreases. Therefore, the thickness of the conductive part 111 is adjusted according to the required detection sensitivity in the application of the sensing device 10.

[0038] The thickness of the conductive portion 111 is adjusted to approximately 100 μm when, for example, the sensing device 10 is applied to the steering wheel 20. Typically, the thickness of the electrodes or heating elements of the touch sensor disposed on the rim 210 of the steering wheel 20 is approximately 1 mm. Therefore, by replacing the aforementioned electrode or heating element structure with the sensing device 10, adjusting the thickness of the rim 210 becomes easier. More specifically, the rim 210 of the steering wheel 20 is designed within a specific thickness range that makes it easy for the driver to grip. By replacing the aforementioned electrode or heating element structure with the sensing device 10, it is easier to adjust the thickness of the rim 210 within this range compared to the conventional use of thicker electrodes or heating elements.

[0039] Furthermore, by replacing the sensing device 10, the structural elements of the rim 210 are thinner, making the rim 210 as a whole easier to heat up. Based on this, since the proportion of electrodes or heating elements in the cross-section of the rim 210 is smaller, the types of molds required for forming the rim 210 may also be reduced.

[0040] Figure 2 The cover 120 shown is laminated to cover the conductive portion 111. The cover 120 is made of a soft, insulating material. The specific material is selected depending on the application of the sensing device 10. In the case where the sensing device 10 is applied to the steering wheel 20, the cover 120 is made of leather, for example. However, the cover 120 may also be made of a resinous material.

[0041] The thickness of the cover portion 120 is adjusted based on the sensitivity required by the sensing device 10 for detecting contact with an object. For example, when the conductive portion 111 is used as an electrode of a capacitive touch sensor, the thickness of the cover portion 120 determines the distance between the contacting object and the conductive portion 111. The shorter this distance, the greater the change in capacitance, and therefore the thinner the cover portion 120, the higher the detection sensitivity. Therefore, the thickness of the cover portion 120 is adjusted to match the required detection sensitivity.

[0042] Figure 1 The sensor circuit 130 shown detects an object in contact with the cover portion 120. Specifically, the sensor circuit 130 is a circuit for operating a capacitive touch sensor. The sensor circuit 130 has a detection circuit (not shown) and a sensor wiring connection portion 131 electrically connected to a conductive portion 111. Furthermore, the sensor circuit 130 uses the conductive portion 111 as an electrode to detect contact with the object. In addition, the detection circuit includes a power supply and a microcontroller.

[0043] That is, the sensor circuit 130 controls the charging and discharging of the conductive part 111 via the sensor wiring connection 131 through the detection circuit. When an object comes into contact with the covering part 120, the capacitance of the conductive part 111 changes as the object approaches. The sensor circuit 130 detects the voltage change accompanying the capacitance change, thereby detecting the contact of the object. In other words, the sensor circuit 130 detects the object based on the change in the state of the conductive part 111.

[0044] Figure 2 The sensor wiring connection 131 shown is configured to be supported on the substrate 112 within the load portion 110. More specifically, the sensor wiring connection 131 is engaged with the portion of the substrate 112 where the conductive portion 111 is located. Thus, the sensor wiring connection 131 is electrically connected to the conductive portion 111. For example, if the substrate 112 is made of knitted material, the sensor wiring connection 131 is engaged by being woven into the substrate 112 at the portion where the conductive portion 111 is located.

[0045] Therefore, the sensor wiring connection 131 is made of conductive fibers. For example, the sensor wiring connection 131 is made of a conductive composite material obtained by winding copper fibers onto polyester yarn. However, the sensor wiring connection 131 may also be made of fibers plated with metal or fibers made of pure metal.

[0046] Furthermore, the position of the sensor wiring connection portion 131 on the substrate portion 112 will be described in detail later.

[0047] Figure 1 The heater circuit 140 shown heats the conductive part 111. The heater circuit 140 includes a temperature control unit comprised of a microcontroller and a power supply. The temperature control unit and power supply are not shown in the diagram. The heater circuit 140 has a positive terminal wiring connection 141 and a negative terminal wiring connection 142 electrically connected to the conductive part 111. Based on this, the heater circuit 140 uses the conductive part 111 as a heating element. That is, the positive terminal wiring connection 141 and the negative terminal wiring connection 142 function as electrodes of the heating element. The heater circuit 140 heats the conductive part 111 according to its resistance value by supplying power from the positive terminal wiring connection 141 to the negative terminal wiring connection 142 via the power supply. That is, the conductive part 111 is heated between the positive terminal wiring connection 141 and the negative terminal wiring connection 142. Furthermore, the heater circuit 140 adjusts the temperature of the conductive part 111 by adjusting the current supplied to the conductive part 111 using the temperature control unit.

[0048] Figure 2The positive electrode wiring connection portion 141 and the negative electrode wiring connection portion 142 shown are configured to be supported on the substrate portion 112 within the load portion 110. The positive electrode wiring connection portion 141 and the negative electrode wiring connection portion 142 are joined to the portion of the substrate portion 112 where the conductive portion 111 is located using the same method as the joining method between the sensor wiring connection portion 131 and the substrate portion 112. Thus, the positive electrode wiring connection portion 141 and the negative electrode wiring connection portion 142 are electrically connected to the conductive portion 111.

[0049] like Figure 2 As shown, in the cross-section representing the laminated structure of the conductive portion 111 and the covering portion 120, the sensor wiring connection portion 131, the positive electrode wiring connection portion 141, and the negative electrode wiring connection portion 142 are in contact with the layer representing the conductive portion 111, and are disposed separately from each other. That is, each wiring connection portion is supported on the substrate portion 112 in a state that includes a part of the layer composed of the conductive portion 111. Furthermore, each wiring connection portion is configured not to overlap with each other in the cross-section.

[0050] However, each wiring connection may also be a structure that does not include a part of the layer composed of the conductive part 111. Each wiring connection only needs to be in contact with the layer representing the conductive part 111. That is, each wiring connection may also be configured to rest on the boundary surface of the layer representing the conductive part 111.

[0051] Furthermore, each wiring connection is electrically connected via the conductive part 111. However, the current flowing between the wiring connections via the conductive part 111 is less likely to flow compared to the case where the wiring connections are directly connected. In this specification, the state where the wiring connections are directly connected refers to a short-circuit state. Therefore, the state where the wiring connections are electrically connected via the conductive part 111 does not include a short-circuit state.

[0052] A-2. Location of each wiring connection: When the substrate portion 112 is unfolded into a plane, the substrate portion 112 has a rectangular shape. Therefore, as... Figure 1 As shown, the substrate portion 112 has a pair of long sides 112L and a pair of short sides 112S.

[0053] The sensor wiring connection portion 131 is provided along the short side 112S of the substrate portion 112. That is, the sensor wiring connection portion 131 is arranged in a strip shape parallel to the short side 112S.

[0054] The positive electrode wiring connection portion 141 is provided along one long side 112L of the substrate portion 112. The negative electrode wiring connection portion 142 is provided along the other long side 112L of the substrate portion 112. The positive electrode wiring connection portion 141 and the negative electrode wiring connection portion 142 are arranged in a strip shape parallel to the long side 112L.

[0055] As described above, with this structure, the sensing device 10 can be applied to various objects. Furthermore, the sensing device 10 can detect the contact of objects and heat up the application object.

[0056] In this configuration, the sensor wiring connection 131, the positive electrode wiring connection 141, and the negative electrode wiring connection 142 are in contact with the layer representing the conductive portion 111, but are disposed separately from each other. Therefore, short circuits caused by direct contact between the connections are less likely to occur. By configuring it in this way, the sensing device 10 of this embodiment can suppress mutual contact even if any of the sensor wiring connection 131, the positive electrode wiring connection 141, and the negative electrode wiring connection 142 deforms when pressure is applied to the conductive portion 111 by an object in contact with the covering portion 120. That is, the sensing device 10 of this embodiment can suppress short circuits between the sensor circuit 130 and the heater circuit 140.

[0057] Furthermore, the positive electrode wiring connection 141 and the negative electrode wiring connection 142 are arranged along the long side 112L. In this manner, the distance between them is shorter compared to the case where the positive electrode wiring connection 141 and the negative electrode wiring connection 142 are arranged along the short side 112S. When the conductive part 111 is heated by the heater circuit 140, the amount of heat generated varies depending on the resistance value of the conductive part 111. The resistance value of the conductive part 111 depends on the distance between the positive electrode wiring connection 141 and the negative electrode wiring connection 142. That is, the resistance value of the conductive part 111 is smaller compared to the case where the positive electrode wiring connection 141 and the negative electrode wiring connection 142 are arranged along the short side 112S. The smaller the resistance value, the higher the possibility that the sensing device 10 of this embodiment can reduce the applied voltage. Therefore, in the sensing device 10 of this embodiment, it is possible to easily design the heater circuit 140.

[0058] B. Second Implementation Method: Figure 3 This is an explanatory diagram showing a schematic structure of the sensing device 10a according to the second embodiment. In the above embodiment, the positive electrode wiring connection portion 141a and the negative electrode wiring connection portion 142a may also be provided separately from the two ends 112E of the short side 112S where the sensor wiring connection portion 131 is located. More specifically, Figure 3 In the second embodiment, when viewing the load section 110a along the Y-axis, the positive electrode wiring connection section 141a and the negative electrode wiring connection section 142a can be configured such that their ranges do not overlap with the range of the sensor wiring connection section 131. Furthermore, in the second embodiment, the same reference numerals are used for structural elements identical to those in the first embodiment. Also, in the second embodiment, structural elements having functions different from those in the first embodiment are labeled with "a".

[0059] By configuring it in this way, the sensor wiring connection portion 131, which is provided along the short side 112S of the substrate portion 112, and the positive electrode wiring connection portion 141a and the negative electrode wiring connection portion 142a, which are provided along the long side 112L of the substrate portion 112, are not easily approached. As a result, the sensing device 10a of this embodiment can prevent the sensor wiring connection portion 131 from contacting the positive electrode wiring connection portion 141a or the negative electrode wiring connection portion 142a.

[0060] C. Third implementation method: Figure 4 This is an explanatory diagram showing the schematic structure of the sensing device 10b according to the third embodiment. In addition to the structure of the sensing device 10 of the first embodiment, the sensing device 10b may also include a control circuit 160 and a switching circuit 150. Therefore, the circuit section 11b of the third embodiment has a structure that includes the control circuit 160 and the switching circuit 150. Furthermore, in the third embodiment, the same reference numerals are used to denote the same structural elements as in the first embodiment. In the third embodiment, structural elements having functions different from those in the first embodiment are labeled with "b". Furthermore, in... Figure 4 The illustration of a portion of the load section 110 is omitted.

[0061] Switching circuit 150 switches the operation of sensor circuit 130b and heater circuit 140. Switching circuit 150 includes, for example, a relay and its drive circuit. The relay switches the power supply to sensor circuit 130b and heater circuit 140. That is, based on the command of control circuit 160, switching circuit 150 activates the relay via drive circuit, thereby supplying power to either sensor circuit 130b or heater circuit 140.

[0062] In the third embodiment, the sensor circuit 130b is also capable of disconnecting the connection to the conductive part 111. For example, the sensor circuit 130b has a relay in the wiring connected to the conductive part 111. By disconnecting the relay, the sensor circuit 130b disconnects the electrical connection between the sensor circuit 130b and the conductive part 111.

[0063] Furthermore, in the circuit described above, the element implemented by the relay can also be implemented by a semiconductor switch such as a transistor.

[0064] Control circuit 160 controls sensing device 10b. Specifically, control circuit 160 is a microcontroller. Alternatively, control circuit 160 can also be used as a microcontroller for sensor circuit 130b or heater circuit 140. Control circuit 160 switches the operation of sensor circuit 130b and heater circuit 140 via switching circuit 150. That is, control circuit 160 enables either the object contact detection performed by sensor circuit 130b or the heating of conductive part 111 performed by heater circuit 140 via switching circuit 150. Furthermore, during operation of heater circuit 140, control circuit 160 disconnects the connection between sensor circuit 130b and conductive part 111 via sensor circuit 130b.

[0065] By configuring it in this way, the sensor circuit 130b and the heater circuit 140 do not operate simultaneously. Furthermore, the sensor circuit 130b is disconnected from the conductive part 111 during the operation of the heater circuit 140. Normally, the voltage applied to heat the conductive part 111 is higher than the voltage applied to the conductive part 111 for detection purposes. Therefore, during the operation of the heater circuit 140, if the sensor circuit 130b is connected to the conductive part 111, current may flow from the heater circuit 140 to the sensor circuit 130b. However, by disconnecting the current flow from the heater circuit 140 to the sensor circuit 130b, the sensing device 10b of this embodiment can suppress malfunctions caused by the current flow to the sensor circuit 130b.

[0066] D. Fourth implementation method: As described above, the sensing device 10, located on the rim 210 of the steering wheel 20, can detect the driver's grip on the rim 210 and warm the driver's hand via the rim 210. The steering wheel 20 to which the sensing device 10 is applied will be described below.

[0067] Figure 5 This is an explanatory diagram of the steering wheel 20 according to the fourth embodiment. Figure 5 The figure shows a plan view of the steering wheel 20 as viewed from the driver's perspective. The steering wheel 20 has a rim 210 formed in a circular shape, spokes 220 extending from the rim 210 toward the center of the rim 210, a cover 230 located at the center of the spokes, and a sensing device 10.

[0068] The sensing device 10 applied to the steering wheel 20 Figure 5 In the top view, the rim 210 portion of the steering wheel 20 is separately arranged in the right half and the left half of the rim 210 portion. The long side 112L of the substrate portion 112 of each sensing device 10 is arranged in the direction extending from the annular rim 210. Therefore, the sensor wiring connection portion 131 is, for example, in Figure 5 In the top view, it is located at the bottom of the steering wheel 20. However, the sensor wiring connection part 131 is... Figure 5 In the plan view, it can also be located on the upper side of the steering wheel 20. The circuit section 11, including sensor circuitry 130 or heater circuitry 140, is housed, for example, inside the wheel spokes 220. Furthermore, for ease of understanding of the technology, in Figure 5 The wiring diagram is omitted in the text.

[0069] Furthermore, one or more sensing devices 10 can be configured on the steering wheel 20. Also, the sensing devices 10 can be configured on a portion of the wheel rim 210.

[0070] Figure 6 This is a cross-sectional view of the rim 210 of the steering wheel 20. Figure 6 The figure shows a cross-sectional view perpendicular to the direction in which the annular rim 210 extends. The rim 210 is the part of the steering wheel 20 that the driver grips. The rim 210 has a circular cross-section. Inside the cross-section, the rim 210 has a metal core 211 for maintaining the shape of the rim 210 and a metal core cover 212 covering the metal core 211. However, the rim 210 may also not have the metal core cover 212.

[0071] The sensing device 10 is disposed inside the rim 210 in a curved state along the profile of the cross-section of the rim 210. Thus, as... Figure 5 As shown, the positive terminal wiring connection 141 and the negative terminal wiring connection 142 are located on the side of the rim 210 where the cover 230 is located.

[0072] like Figure 6 As shown, the load portion 110 and the cover portion 120 of the sensing device 10 are arranged on the rim 210 such that they cover the metal core portion 211. More specifically, the load portion 110 covers the metal core portion 211 when the substrate portion 112 is in contact with the metal core cover portion 212. Furthermore, the cover portion 120 is stacked on top of the load portion 110. As described above, the sensing device 10 constitutes the outermost layer of the rim 210.

[0073] As described above, if the driver grips the wheel rim 210, their hand comes into direct contact with the cover 120 that forms the surface of the wheel rim 210. The sensing device 10 detects this contact via the sensor circuit 130. Furthermore, the sensing device 10 heats the entire wheel rim 210 by heating the conductive part 111 using the heater circuit 140.

[0074] In this configuration, the sensor wiring connection 131, the positive wiring connection 141, and the negative wiring connection 142 are in contact with the layer representing the conductive portion 111, but are arranged separately from each other. Therefore, short circuits caused by direct contact between the connections are less likely to occur. By configuring it in this way, even if any of the sensor wiring connection 131, the positive wiring connection 141, and the negative wiring connection 142 deforms when pressure is applied to the conductive portion 111 by an object in contact with the cover portion 120, the steering wheel 20 of this embodiment can suppress mutual contact. That is, the steering wheel 20 of this embodiment can suppress short circuits between the sensor circuit 130 and the heater circuit 140.

[0075] E. Fifth implementation method: In the above embodiments, the control circuit 160 may also have a switching mode and a sensor operating mode.

[0076] The sensor operating mode only activates the sensor circuit 130 within the heater circuit 140 and the sensor circuit 130. Depending on the ambient temperature of the environment where the sensing device 10 is used, it may not be necessary to heat the conductive part 111. In this case, the sensing device 10 does not heat the conductive part 111.

[0077] The switching mode alternately switches the operation of the heater circuit 140 and the sensor circuit 130. More specifically, the switching mode alternately switches the operation of the heater circuit 140 and the sensor circuit 130 at intervals of less than 1 second. As a result, the sensing device 10 can achieve substantially the same detection function and heat the conductive part 111.

[0078] Based on this, the control circuit 160 can also switch between the two modes according to the user's instructions. The user's instructions can be made, for example, by the user touching the cover 120. However, the sensing device 10 may also have an operation unit, thereby inputting the user's instructions to the control circuit 160.

[0079] By configuring it in this way, the control circuit 160 can detect objects in contact with the cover portion 120 without heating the conductive part 111 in the sensor operating mode. Furthermore, the control circuit 160 can achieve the same detection function and heat the conductive part 111 by switching modes. Therefore, compared to operating only one of the sensor circuit 130 and the heater circuit 140, the sensing device 10 of this embodiment achieves greater convenience.

[0080] F. Other implementation methods: (F1) In the above embodiment, the sensor circuit 130 detects the contact by detecting the change in capacitance caused by the contact of an object. However, the sensor circuit 130 may also detect the contact by detecting the change in resistance caused by the contact of an object. That is, the sensor circuit 130 may also be a circuit for operating a resistive film type touch sensor.

[0081] Furthermore, the sensor circuit 130 can also be a circuit for detecting water droplets attached to the cover portion 120. More specifically, the sensor circuit 130 detects the water droplet based on the change in capacitance of the conductive portion 111 caused by the water droplet attaching to the cover portion 120.

[0082] (F2) In the above embodiment, the substrate portion 112 and the cover portion 120 are different structural elements. However, the substrate portion 112 and the cover portion 120 can be constructed from the same element. In this case, the load portion 110 is configured such that a conductive portion 111 is disposed on one side of the cover portion 120, and the object contacts the other side of the cover portion 120. That is, the conductive portion 111 is formed by directly applying a conductive coating to the side of the cover portion 120 opposite to the side exposed to the outside. Furthermore, the sensor wiring connection portion 131, the positive electrode wiring connection portion 141, and the negative electrode wiring connection portion 142 are in contact with the layer representing the conductive portion 111 and are disposed separately from each other in the cover portion 120. By configuring it in this way, the components constituting the substrate portion 112 can be reduced in terms of the sensing device 10. Furthermore, compared to the case where the substrate portion 112 and the cover portion 120 have different structural elements, the sensing device 10 can reduce the thickness of the load portion 110.

[0083] (F3) In the above embodiment, the steering wheel 20 has a metal core 211 inside the rim 210. However, the steering wheel 20 may also have a rim 210 with a shell structure. The rim 210 with a shell structure has a hollow cross-section. Regarding the rim 210 with a shell structure, the component corresponding to the metal core 211 of the rim 210 in the above embodiment constitutes the outermost layer of the hollow cross-section. That is, the shape of the rim 210 is maintained by the outermost layer. Therefore, the rim 210 with a shell structure does not have a metal core 211 inside. In this case, the base material 112 and the cover 120 may also be constituted by the outermost layer. That is, the conductive part 111 is formed on the inner surface of the outermost layer by coating the inner surface of the outermost layer with a conductive coating.

[0084] (F4) In the above embodiment, the substrate portion 112 has a rectangular shape. However, the substrate portion 112 may also be configured with other shapes depending on the shape of the object to which the sensing device 10 is applied. For example, the substrate portion 112 may also be quadrilateral or circular. Furthermore, the portion of the substrate portion 112 may protrude from the outer shape at the location of each wiring connection portion. For example, in the rectangular substrate portion 112, a portion located on the short side 112S may protrude from the rectangular outer shape. Furthermore, the sensor wiring connection portion 131 may be located at this location. By configuring it in this way, it is easy to separate the wiring connections from each other.

[0085] (F5) In the above embodiment, the sensor wiring connection portion 131 is provided along the short side 112S of the substrate portion 112. The positive electrode wiring connection portion 141 is provided along one long side 112L of the substrate portion 112. The negative electrode wiring connection portion 142 is provided along the other long side 112L of the substrate portion 112. However, the sensor wiring connection portion 131 may also be provided along the long side 112L of the substrate portion 112. In this case, the positive electrode wiring connection portion 141 is provided along one short side 112S of the substrate portion 112. The negative electrode wiring connection portion 142 is provided along the other short side 112S of the substrate portion 112.

[0086] (F6) In the above embodiment, the sensing device 10 may also have an insulator at the closest positions of the positive terminal wiring connection 141 and the sensor wiring connection 131. Similarly, the sensing device 10 may have an insulator at the closest positions of the negative terminal wiring connection 142 and the sensor wiring connection 131. The insulator may be formed, for example, by applying an insulating coating. By configuring it in this way, the sensing device 10 can effectively prevent short circuits at the corresponding closest positions.

[0087] (F7) In the above embodiment, the rim 210 of the steering wheel 20 is circular. However, the rim 210 is not limited to a circular shape, and may be any shape such as a polygonal outline or an elliptical outline. In addition, the rim 210 is not limited to a ring shape, and may be composed of multiple grip portions that are not continuous with each other, such as the grip portion on the right and the grip portion on the left.

[0088] (F8) In the above embodiments, as Figure 5 As shown, the positive terminal wiring connection 141 and the negative terminal wiring connection 142 are located on the side of the trim cover 230 within the wheel rim 210. That is, the positive terminal wiring connection 141 and the negative terminal wiring connection 142 are located on the inner side of the steering wheel 20. However, the positive terminal wiring connection 141 and the negative terminal wiring connection 142 may also be located on the outer side of the steering wheel 20.

[0089] This invention is not limited to the embodiments described above, and can be implemented in various structures without departing from its spirit. For example, the technical features of the embodiments corresponding to the technical features in the various aspects described in the summary section of the invention can be appropriately replaced or combined to solve some or all of the above-described problems, or to achieve some or all of the above-described effects. In addition, any technical feature that is not described as an essential feature in this specification can be appropriately deleted.

[0090] Explanation of the label

[0091] 10, 10a, 10b… Sensing device; 11, 11b… Circuit section; 20… Steering wheel; 110, 110a… Load section; 111… Conductive section; 112… Substrate section; 112E… Both ends; 112L… Long side; 112S… Short side; 120… Cover section; 130, 130b… Sensor circuit; 131… Sensor wiring connection section; 140… Heater circuit; 141, 141a… Positive wiring connection section; 142, 142a… Negative wiring connection section; 150… Switching circuit; 160… Control circuit; 210… Wheel rim; 211… Metal core; 212… Metal core cover; 220… Wheel spoke; 230… Trim cover

Claims

1. A sensing device comprising: A load portion having a conductive portion and a substrate portion, the conductive portion being conductive, the substrate portion being configured to support the conductive portion and being covered by the conductive portion; A covering portion, which is stacked in a manner that covers the conductive portion; Sensor circuitry that detects objects in contact with the cover; and The heater circuit heats the conductive part. The sensor circuit detects the object based on changes in the state of the conductive part. It has a sensor wiring connection portion that is electrically connected to the conductive portion and is supported on the substrate portion in the load portion. The heater circuit has a positive terminal wiring connection and a negative terminal wiring connection, which are electrically connected to the conductive part and supported on the substrate part in the load part. The conductive part is heated between the positive electrode wiring connection and the negative electrode wiring connection. In the cross-section showing the stacked structure of the conductive part and the covering part, the sensor wiring connection part, the positive electrode wiring connection part, and the negative electrode wiring connection part are in contact with the layer showing the conductive part, and are disposed separately from each other.

2. The sensing device according to claim 1, wherein, It also has: A switching circuit that switches the operation of the sensor circuit and the heater circuit; and The control circuit controls the sensing device. The sensor circuit can also disconnect from the conductive part. The control circuit switches the operation of the sensor circuit and the heater circuit via the switching circuit. During operation of the heater circuit, the connection between the sensor circuit and the conductive part is disconnected via the sensor circuit.

3. The sensing device according to claim 1 or 2, wherein, When the substrate portion is unfolded into a plane... The substrate portion is rectangular in shape. The sensor wiring connection portion is provided along the short side of the substrate portion. The positive electrode wiring connection portion is provided along one long side of the substrate portion. The negative electrode wiring connection is provided along another long side of the substrate portion.

4. The sensing device according to claim 3, wherein, When the substrate portion is unfolded into a plane... The positive electrode wiring connection and the negative electrode wiring connection are separately disposed from the two ends of the short side where the sensor wiring connection is located.

5. The sensing device according to claim 2, wherein, The control circuit also has: A switching mode that alternately switches the operation of the heater circuit and the sensor circuit; and The sensor operating mode activates only the heater circuit and the sensor circuit within the sensor circuit. Switch the switching mode and the sensor operating mode according to the user's instructions.

6. A steering wheel having: The rim, which is held by the driver, has a metal core inside its cross-section; and Sensing devices, The sensing device has: A load portion having a conductive portion and a substrate portion, the conductive portion being conductive, the substrate portion being configured to support the conductive portion and being covered by the conductive portion; A covering portion, which is stacked in a manner that covers the conductive portion; Sensor circuitry that detects objects in contact with the cover; and The heater circuit heats the conductive part. The load-bearing portion and the covering portion are arranged on the rim in a manner that covers the metal core. The sensor circuit detects the object based on changes in the state of the conductive part. It has a sensor wiring connection portion that is electrically connected to the conductive portion and is supported on the substrate portion in the load portion. The heater circuit has a positive terminal wiring connection and a negative terminal wiring connection, which are electrically connected to the conductive part and supported on the substrate part in the load part. The conductive part is heated between the positive electrode wiring connection and the negative electrode wiring connection. In the cross-section showing the stacked structure of the conductive part and the covering part, the sensor wiring connection part, the positive electrode wiring connection part, and the negative electrode wiring connection part are in contact with the layer showing the conductive part, and are disposed separately from each other.

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