JP2011165384A - Switch device with touch detection function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the feel of an operation for an operation knob while sufficiently securing conduction between an electrode for touch detection and an electrical connecting section of a wiring board in a switch device with touch detection function. <P>SOLUTION: The operation knob 2 is provided to be able to be rocked through a shaft section 4 and a connecting conductor 9 for electrically connecting the electrode 8 for touch detection provided on the operation knob 2 to the electrical connecting section 12 of the wiring board 11 is made to pass through the vicinity of the shaft section 4. Thus, hardly any influence is given to the operational force when rocking and operating the operation knob 2 even when an elastic force in an elastic section 10 and an elastic rubber 19 is made large so that an end section of the connecting conductor 9 comes into elastic and electrical contact with the electrical connecting section 12. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a switch device with a touch detection function having a touch detection electrode for detecting when a finger touches an operation knob.

  Conventionally, there has been proposed a switch device with a touch detection function configured to detect when a finger touches the operation knob of the switch device and to change the display state of the selection unit corresponding to the operation knob. (Patent Document 1).

  In this switch device, as shown in FIG. 4, a wiring board 103 having an electrical connection portion 102 is disposed below the operation knob 101. The wiring board 103 has a switch element 104 and an elastic contact means. A leaf spring contact 105 is provided. Further, the operation knob 101 is provided with a thin-film-like touch detection electrode 106, and a part of the touch detection electrode 106 is led out to the lower surface of the large portion 101a of the operation knob 101 to form a connection conductor 106a. Has been.

  The contact 105 described above has a substantially inverted V shape, one end is fixed to the wiring board 103, the other end is in sliding contact with the electrical connection portion 102, and the intermediate portion is connected to the connection conductor 106a at the lower end of the operation knob 101. The touch detection electrode 106 is electrically connected to the electrical connection portion 102 of the wiring substrate 103 by being elastically pressed from below.

  According to the switch device having such a configuration, when a finger touches the operation knob 101, the selection unit corresponding to the operation knob 101 is displayed on the screen of the display device, and when the operation knob 101 is pressed in this state, The switch element 104 operates to determine the selection of the selection unit. Thus, since the position of the operation knob 101 with which the finger is in contact is known by looking at the screen of the display device, it is possible to operate by looking at only the screen of the display device without looking at the operation knob 101.

  Further, according to the configuration described above, there is no need for a connector for electrically connecting the touch detection electrode 106 to the electrical connection portion 102 of the wiring board 103, which improves assembly and reduces costs. There are advantages that are possible.

JP 2008-059912 A

  However, in the configuration of Patent Document 1, the contact pressure between the connection conductor 106 a and the contact 105 is sufficient to ensure sufficient conduction between the touch detection electrode 106 and the electrical connection portion 102 of the wiring board 103. However, if the elastic force of the contact 105 is increased, the increase in the elastic force is directly superimposed on the operation load of the operation knob 101. There is a problem that the operation force when operating the operation knob 101 is increased, and the feeling (stroke-operation load characteristics) during operation of the operation knob 101 is deteriorated.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to elastically connect the connection conductor to the electrical connection portion in order to ensure sufficient conduction between the touch detection electrode and the electrical connection portion of the wiring board. Provided is a switch device with a touch detection function capable of hardly affecting the operation force when operating an operation knob even if the elastic force by an elastic contact means for making contact is electrically and electrically increased. There is.

  In order to achieve the above object, a switch device with a touch detection function according to the present invention is provided on an operation knob provided so as to be able to swing around a shaft portion, and on the operation knob in order to detect contact of a finger. A touch detection electrode, a wiring board having an electrical connection portion, a switch element that is provided on the wiring board and that is pressed based on a swing operation of the operation knob, and one end portion of the electrode near the shaft portion. A connection conductor that is electrically connected to the touch detection electrode and the other end is led to the wiring board side, and the other end of the connection conductor is elastically and electrically connected to the electrical connection. And an elastic contact means for contact.

  According to the above means, the connection conductor for electrically connecting the touch detection electrode to the electrical connection portion of the wiring board passes through the vicinity of the shaft portion serving as the swing center of the operation knob operated to swing. Even if the elastic force by the elastic contact means for elastically and electrically contacting the other end portion of the connection conductor to the electrical connection portion is increased, the operation force when swinging the operation knob is It can be made almost unaffected.

The longitudinal cross-sectional view of the switch apparatus with a touch detection function which shows one Example of this invention Fig. 1 equivalent when the operation knob is operated The figure which shows the equivalent circuit of the touch detection circuit Vertical section of a conventional switch device with touch detection function

Hereinafter, an embodiment in which the present invention is applied to a switch device with a touch detection function used in an automobile will be described with reference to FIGS.
FIG. 1 is a longitudinal sectional view of a switch device with a touch detection function. A body 1 as a switch body has a rectangular box shape with an open lower surface in FIG. 1, and is formed of, for example, a synthetic resin. An opening 3 for arranging the operation knob 2 is provided in the upper part of the body 1, and the operation knob 2 is supported so as to be swingable via a shaft portion 4 provided at one end of the operation knob 2. ing. The operation knob 2 is also made of, for example, a synthetic resin. Further, a guide portion 5 extending in the vertical direction in FIG. 1 is provided inside the body 1.

  A projecting portion 6 is provided at the other end of the operation knob 2 (the end opposite to the shaft portion 4). The operation knob 2 is prevented from coming off the body 1 upward by the projecting portion 6. Yes. Below the operation knob 2, a rod-like pusher 7 having a rounded upper portion and a lower portion is disposed. The pusher 7 is supported so as to be linearly movable in the vertical direction by being inserted into the guide portion 5.

  A touch detection electrode 8 made of a thin plate-like conductive member is provided on the entire surface of the operation knob 2. The touch detection electrode 8 is for detecting that a human finger has come into contact with the operation knob 2. A thin plate-like connection conductor 9 made of the same conductive member as the touch detection electrode 8 is integrally connected to the touch detection electrode 8. The connection conductor 9 includes a substantially C-shaped elastic portion 10 (elastic contact means) having spring properties, and one end portion thereof is electrically connected to the touch detection electrode 8 through the vicinity of the shaft portion 4, The other end is led out to the wiring board 11 side (lower side in FIG. 1) described later. In this case, the conductive member that integrally configures the touch detection electrode 8, the connection conductor 9, and the elastic portion 10 is formed of, for example, a copper plate plated with tin.

  As shown in FIG. 1, a wiring board 11 having an electrical connection portion 12 and a fixed contact 13 is disposed below the operation knob 2. The wiring board 11 is mounted so as to close the opening 14 on the lower surface of the body 1. A rubber sheet 15 is provided on the upper surface side of the wiring substrate 11 so as to cover the upper surface side of the wiring substrate 11. The rubber sheet 15 is made of an insulating material having elasticity, such as silicone rubber, and has a flat surface 15a.

  A rubber dome 16 that is elastically deformable in a dome shape covering the fixed contact 13 is provided in a portion corresponding to the fixed contact 13 in the rubber sheet 15. The rubber dome 16 includes an elastically deformable deformable portion 16a bulging upward from the flat surface 15a of the rubber sheet 15, and a columnar pressed portion 16b integrally provided at the upper end of the deformable portion 16a. It is configured. The upper surface of the pressed portion 16b of the rubber dome 16 is in contact with the pusher 7 from below, and the operation knob 2 is biased upward by the elastic force of the deformation portion 16a.

  A movable contact 17 is provided on the inner surface of the rubber dome 16 on the lower surface of the pressed portion 16 b so as to face the fixed contact 13. With the elastic deformation of the deforming portion 16 a in the rubber dome 16, the movable contact 17 comes in contact with and separates from the fixed contact 13, and the fixed contact 13 and the movable contact 17 constitute a switch element 18.

  A conductive rubber 19 having elasticity and conductivity is disposed on the upper surface of the electrical connection portion 12 of the wiring board 11. The conductive rubber 19 is made of, for example, silicone rubber added with carbon black as a conductive agent, and is integrated with the rubber sheet 15, and its lower surface is in contact with the electrical connection portion 12. On the upper surface of the conductive rubber 19, the other end portion of the connection conductor 9 is L-shaped and is in pressure contact. As a result, the conductive rubber 19 and the elastic portion 10 are configured to elastically and electrically contact the connection conductor 9 with the electrical connection portion 12 as elastic contact means.

  Next, the touch detection circuit 20 of the switch device with a touch detection function will be described with reference to FIG. The touch detection circuit 20 is a general capacitance detection circuit, and includes an oscillation unit 21 having one terminal that outputs a high-frequency signal connected to the ground, a load resistor 22, and a detection unit that detects and smoothes the high-frequency signal. 23 and an operational amplifier 24.

  The touch detection electrode 8 is connected to the output terminal (the other terminal) of the oscillating unit 21 through the load resistor 22, the electrical connection unit 12, the conductive rubber 19, and the connection conductor 9. The detection unit 23 includes a diode, a capacitor, and the like, and a high-frequency signal from the oscillation unit 21 is input via the load resistor 22. The output of the detector 23 is input to a control device (not shown) as an amplified and offset signal Vout via the operational amplifier 24. The oscillation unit 21, the load resistor 22, the detection unit 23, and the operational amplifier 24 are configured as a packaged capacitance detection IC 25.

Next, the operation of this embodiment will be described.
When the user's finger touches the upper surface of the operation knob 2, the user's finger is connected to the ground, so that a variable capacitor C is formed by the user's finger and the touch detection electrode 8. The capacitance of the capacitor C hardly changes. Thereby, the electrical connection part 12 of the wiring board 11 is connected to the ground via the conductive rubber 19, the connection conductor 9, the capacitor C, and fingers. Therefore, the high frequency signal output from the oscillating unit 21 is divided by the resistance value of the load resistor 22 and the impedance of the capacitor C and input to the detecting unit 23.

  As a result, the level of the high-frequency signal input to the detection unit 23 is smaller than in the state where the finger is not touching the operation knob 2, so the level of the signal Vout output via the detection unit 23 and the operational amplifier 24 is also high. Get smaller. The control device (not shown) detects the touch of the finger to the operation knob 2 by the change in the level of the signal Vout, and temporarily selects the selection unit corresponding to the operation knob 2 on the screen of the display device (not shown). Display.

  Thereafter, when the operation knob 2 is swung downward by the user, as shown in FIG. 2, the pusher 7 moves downward as the operation knob 2 swings downward around the shaft portion 4. The pressed portion 16 b of the rubber dome 16 is pushed downward, and the movable contact 17 contacts the fixed contact 13. As a result, the switch element 18 is turned on. Upon receiving the ON signal of the switch element 18, the control device changes the selection unit corresponding to the operation knob 2 to a fixed display state, and selects the selection unit. decide. After the operation, when the user releases his / her finger from the operation knob 2, the operation knob 2 returns to the original position by the biasing force of the rubber dome 16.

According to the present embodiment, the center of swing of the operation knob 2 is operated to swing the connection conductor 9 for electrically connecting the touch detection electrode 8 to the electrical connection portion 12 of the wiring board 11. Since it passes through the vicinity of the shaft portion 4, the other end portion of the connecting conductor 9 is elastically contacted with the elastic portion 10 and the conductive rubber 19 for elastically and electrically contacting the electrical connecting portion 12. Even if the elastic force is increased, the operation force when the operation knob 2 is swung can be hardly affected.
That is, the feeling (stroke) during operation of the operation knob 2 is ensured while increasing the elastic force of the elastic portion 10 and the conductive rubber 19 to ensure sufficient conduction between the touch detection electrode 8 and the electrical connection portion 12. -The operating load characteristics can be improved.

  Further, although the elastic portion 10 and the conductive rubber 19 are provided as elastic contact means, only one of them can make the connection conductor 9 elastically and electrically contact the electrical connection portion 12. In this embodiment, the reliability of electrical connection can be further enhanced by using two elastic contact means of the elastic portion 10 and the conductive rubber 19.

When only the elastic part 10 is used as the elastic contact means without using the conductive rubber 19, the other end of the connection conductor 9 may be directly pressed against the upper surface of the electrical connection part 12, and in this case as well, the elastic part The continuity between the touch detection electrode 8 and the electrical connection portion 12 can be sufficiently secured by the elastic force of 10.
Even when the connection conductor 9 does not have the elastic portion 10 and only the conductive rubber 19 is used as the elastic contact means, the conduction between the touch detection electrode 8 and the electrical connection portion 12 is sufficiently achieved by the elastic force of the conductive rubber 19. It can be secured.

  Further, according to the present embodiment, the touch detection electrode 8, the connection conductor 9, and the elastic portion 10 are constituted by a continuous and integral conductive member, so that the number of parts can be reduced and the assemblability is improved. You can also

  Further, the touch detection electrode 8 can be electrically connected to the electrical connection portion 12 of the wiring board 11 by the connection conductor 9 and the conductive rubber 19 simply by incorporating the operation knob 2 and the wiring board 11 into the body 1. A connector is not required, and it is possible to improve the assembling property and reduce the cost.

The present invention is not limited to the embodiment described above and shown in the drawings. For example, the shaft portion 4 may be arranged at the center of the operation knob 2. In this case, the operation knob 2 is provided with the shaft portion. 4, the connecting conductor 9 that swings to both the front and rear sides (left and right in FIG. 1) and is connected to the touch detection electrode 8 passes through the vicinity of the shaft portion 4 at the center of the operation knob 2, and connects the switch element 18 to the shaft portion. You may make it arrange | position at two places below the both sides of 4 back and front.
In addition, the present invention can be implemented with appropriate modifications or expansions without departing from the scope of the invention.

  In the drawing, 2 is an operation knob, 4 is a shaft portion, 8 is an electrode for touch detection, 9 is a connection conductor, 10 is an elastic portion (elastic contact means), 11 is a wiring board, 12 is an electrical connection portion, 18 is The switch element 19 is a conductive rubber (elastic contact means).

Claims (4)

An operation knob provided so as to be swingable around a shaft portion;
A touch detection electrode provided on the operation knob to detect that a finger has touched;
A wiring board having an electrical connection;
A switch element provided on the wiring board and operated to be pressed based on a swing operation of the operation knob;
One end portion is electrically connected to the touch detection electrode through the vicinity of the shaft portion, and the other end portion is connected to the wiring board side, and a connection conductor;
A switch device with a touch detection function, comprising: an elastic contact means for elastically and electrically contacting the other end portion of the connection conductor with the electrical connection portion.   The elastic contact means has elasticity and conductivity, and is made of conductive rubber interposed between the other end portion of the connection conductor and the electrical connection portion. The switch device with a touch detection function according to 1.   The touch detection function according to claim 1, wherein the elastic contact means is constituted by an elastic portion provided between the shaft portion and the other end portion in the connection conductor. With switch device.   The switch device with a touch detection function according to claim 3, wherein the touch detection electrode, the connection conductor, and the elastic portion are constituted by a continuous and integral conductive member.

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