Touch switch

Abstract

To realize cost reduction without deteriorating the performance of a touch switch.SOLUTION: A touch switch comprises: a case 1; a circuit board 2 which is housed in the case 1 and in which an electrode 21 for detecting a change in the electrostatic capacitance is patterned on the front surface; a light guide lens 4 which is arranged on the surface of the electrode 21 so as to directly contact the electrode 21 and is made of a dielectric body having the light permeability and elasticity; a control panel 5 which directly contacts the light guide lens 4, is fixed to the case 1 so as to press the light guide lens 4 toward the circuit board 2 and includes a control surface 51 on which a user performs control by bringing a finger 7 of the user close thereto; and a light emission element 21 which irradiates the light guide lens 4 with light. The light emitted to the light guide lens 4 from the light emission element 21 is emitted to the control surface 51 of the control panel 5 via the light guide lens 4.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a capacitive touch switch.

Background Art

[0002] A touch switch 10 of the prior art is shown in FIGS. 5, 6, and 7. FIG. 5 is a perspective view of the touch switch 10, FIG. 6 is an exploded perspective view of the touch switch 10, and FIG. 7 is a cross-sectional view taken along line A-A in FIG. 5. As shown in FIG. 6, the touch switch 10 includes a case 1, a circuit board 2, a housing 3, a light guide lens 4, an operation panel 5, and an electrode sheet 6.

[0003] As shown in FIG. 7, the electrode sheet 6 is attached to the operation panel 5 and connected to the circuit board 2. The touch switch 10 reads the amount of change in capacitance caused by a user touching the operation panel 5 with a finger and determines whether it has been touched. Then, based on this determination result, the touch switch 10 turns on or off a light-emitting element 22 mounted on the circuit board 2. When the light-emitting element 22 is turned on, the light emitted from the light-emitting element 22 passes through the light guide lens 4 and reaches the operation surface 51 of the operation panel 5, so that the user can recognize that the switch operation has been completed by the lighting of the light-emitting element 22.

[0004] Further, Patent Document 1 discloses a touch switch in which light-reflecting particles are dispersedly arranged in a light guide lens, the light-emitting element is arranged on the side of the light guide lens, and light is irradiated from the light-emitting element toward the side surface of the light guide lens. In the touch switch disclosed in Patent Document 1, since the light incident on the light guide lens from the side is diffusely reflected by the light-reflecting particles, a part of the light incident on the light guide lens is emitted toward the operation surface of the operation panel.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the conventional touch switch 10 shown in FIGS. 5 to 7, since the electrode sheet 6 is attached to the operation panel 5, a special attachment process is required so that air or foreign matter does not enter between the electrode sheet 6 and the operation panel 5. Further, when attaching the electrode sheet 6 to the operation panel 5, a process is also required to prevent displacement of the attachment position. Therefore, the manufacturing cost of the conventional touch switch 10 has been high.

[0007] Therefore, an object of the present invention is to achieve cost reduction without degrading the performance of the touch switch.

Means for Solving the Problems

[0008] The touch switch according to the present invention includes a case, a circuit board housed inside the case and having electrodes for detecting a change in capacitance patterned on its surface, Below a light guide lens made of a dielectric having light transmissibility and elasticity, disposed on the surface of the electrode so as to be in direct contact with the electrode, and the light guide lens the upper surface of is in direct contact with the light guide lens, fixed to the case so as to press the light guide lens toward the circuit board, and has an operation panel with an operation surface for performing an operation when a user brings a finger close. comprises It is characterized by the above.

[0009] According to the touch switch of the present invention, by using a dielectric for the light guide lens and patterning the electrodes for detecting a change in capacitance on the circuit board, the process of attaching the electrode sheet to the operation panel becomes unnecessary, so that cost reduction can be achieved without degrading the performance of the touch switch.

[0010] The touch switch of the present invention is mounted on the circuit board so as to be disposed laterally of the light guide lens and includes a light emitting element that irradiates light toward the side surface of the light guide lens, has a light diffusing agent dispersed in the light guide lens , where from the light emitting element to the light guide lens a part of the light incident on the side surface is emitted from the upper surface of the light guide lens toward the operation surface.

[0011] The touch switch according to the present invention According to the present invention, since the light-emitting element is disposed on the side of the light guide lens, the thickness of the entire touch switch can be reduced.

Advantages of the Invention

[0012] The present invention can achieve cost reduction without degrading the performance of the touch switch.

Brief Description of the Drawings

[0013]

FIG. 1

FIG. 2

FIG. 3

FIG. 4

FIG. 5

FIG. 6

FIG. 7

Embodiments for Carrying Out the Invention

[0014] Hereinafter, with reference to the drawings, a touch switch 20 according to an embodiment of the present disclosure will be described. FIG. 1 is a perspective view of the touch switch 20, and FIG. 2 is an exploded perspective view of the touch switch 20. As shown in FIG. 2, the touch switch 20 includes a case 1, a circuit board 2 housed in the case 1, a housing 3, a light guide lens 4, and an operation panel 5. Note that in FIG. 2, the description of electrodes 21 and light-emitting elements 22, which will be described later, is omitted.

[0015] The circuit board 2 is positioned on the housing 3 by positioning pins provided on the lower surface of the housing 3, and is sandwiched and fixed between the case 1 and the housing 3. The housing 3 is provided with ten claws 31 that protrude toward the case 1 and have holes formed in the center. On the outer wall of the side surface of the case 1, ten protrusions 11 are provided at positions corresponding to the claws 31 of the housing 3. When the housing 3 is fixed to the case 1, the protrusions 11 of the case 1 are inserted into the holes formed in the claws 31 of the housing 3. The case 1 is formed with screw holes 12, and the housing 3 is formed with screw through-holes 32 through which screws pass. By inserting a screw through the screw through-hole 32 of the housing 3 into the screw hole 12 of the case 1 and tightening it, the housing 3 is fixed to the case 1.

[0016] The touch switch 20 includes seven light guide lenses 4. The housing 3 is formed with seven lens through-holes 33. The seven light guide lenses 4 are respectively arranged in the lens through-holes 33 of the housing 3. The light guide lens 4 is made of a dielectric having light transmissibility and elasticity such as silicone rubber, and a light diffusing agent is added, and the light diffusing agent is dispersed and arranged inside.

[0017] Figure 3 is a cross-sectional view taken along line B-B in Figure 1. As shown in Figure 3, electrodes 21 are patterned on the surface of the circuit board 2, and the light guide lenses 4 are arranged on the surface of the electrodes 21 so as to be in direct contact with the electrodes 21. Although only one light guide lens 4 is drawn in Figure 3, all seven light guide lenses 4 are arranged on the surface of the electrodes 21 so as to be in direct contact with the electrodes 21. And on the sides of the seven light guide lenses 4, light emitting elements 22 are arranged one on each side. The light emitting element 22 is an LED (Light Emitting Diode) and is mounted on the circuit board 2. The light emitting element 22 irradiates light toward the side surface of the light guide lens 4 as indicated by the arrow in Figure 3.

[0018] The operation panel 5 is directly in contact with the seven light guide lenses 4 and is fixed to the housing 3 by means such as screwing or claw fitting so as to press the light guide lenses 4 toward the circuit board 2. In this way, since the elastic light guide lenses 4 are fixed so as to be sandwiched between the operation panel 5 and the circuit board 2, they are brought into close contact so that air does not enter between the light guide lenses 4 and the operation panel 5, and they are brought into close contact so that air does not enter between the light guide lenses 4 and the electrodes 21.

[0019] The operation panel 5 includes an operation surface 51 on which the user operates the touch switch 20 by bringing a finger close. The operation panel 5 is made of a dielectric such as ABS resin or polycarbonate, and its surface is processed to a piano black finish or a metal plating finish by painting, sputtering, vapor deposition, or film insert. However, the portion where the mark 52 of the operation surface 51 is provided is not painted or the like in this way, and light can pass through. On the operation surface 51 of the operation panel 5, a mark 52 that rises when the light emitting element 22 is lit is provided by film insert molding, printing, painting, or laser cutting.

[0020] FIG. 4 is a diagram showing a state in which a finger 7 is brought close to the operation surface 51 of the operation panel 5. As shown in FIG. 4, when the finger 7 is brought close to the operation panel 5, the operation panel 5 and the light guide lens 4 sandwiched between the finger 7 and the electrode 21 are dielectrics, and since the capacitance between the finger 7 and the electrode 21 changes, the touch switch 20 can determine ON / OFF of the switch based on the increase or decrease in capacitance. And when it is determined that the switch is ON, the touch switch 20 lights the light emitting element 22. When the light emitting element 22 is lit, light is irradiated onto the side surface of the light guide lens 4 as indicated by the arrow in FIG. 3. Then, as already described, since the light diffusing agent is dispersed and arranged in the light guide lens 4, the light incident on the light guide lens 4 from the side surface is diffusely reflected by the light diffusing agent, and a part of the light is emitted from the light guide lens 4 toward the operation surface 51 of the operation panel 5 as indicated by the arrow in FIG. 3. In this way, when the light emitting element 22 is lit, light is emitted toward the operation surface 51, so that the user can recognize that the switch operation is completed by visually observing the light emitted to the operation surface 51.

[0021] In order for the touch switch 20 to detect the amount of change in the capacitance of the capacitor formed between the finger 7 and the electrode 21, in order to improve the sensitivity of the touch switch 20, it is better to increase the dielectric constant of the light guide lens 4 and reduce the distance between the finger 7 and the electrode 21. Therefore, it is desirable that the light guide lens 4 has a relative dielectric constant of 4 or more and the thickness T of the light guide lens 4 shown in FIG. 4 is 4 millimeters or less.

[0022] By using a dielectric for the light guide lens 4, the touch switch 20 enables the electrode 21 for detecting the change in capacitance to be printed on the circuit board 2. By patterning the electrode 21 in this way, unlike the conventional touch switch 10 shown in FIGS. 5 to 7, the touch switch 20 does not require the step of attaching the electrode sheet 6 to the operation panel 5, so cost reduction can be achieved without degrading the performance of the touch switch 20.

[0023] Also, unlike the conventional touch switch 10 shown in FIGS. 5 to 7, since the light emitting element 22 is arranged on the side of the light guide lens 4, the thickness T of the light guide lens 4 can be reduced for the touch switch 20. Since the thickness T of the light guide lens 4 can be reduced in this way and the electrode sheet 6 attached to the operation panel 5 is not required, the overall thickness of the touch switch 20 can be reduced compared to the conventional touch switch 10 shown in FIGS. 5 to 7. Further, by reducing the thickness of the light guide lens 4 in this way, the distance between the finger 7 touching the operation surface 51 and the electrode 21 can be reduced, so the sensitivity of the touch switch 20 can be improved.

[0024] <Supplement to the Embodiment> The touch switch of the present disclosure is not limited to the above-described form and can be implemented in various forms within the scope of the gist of the present disclosure. For example, the number of light guide lenses is not limited to 7, and may be more or less than 7. Also, the light emitting element may be arranged only on one side of the side of the light guide lens.

Explanation of Reference Numerals

[0025] 1 case, 2 circuit board, 3 housing, 4 light guide lens, 5 operation panel, 6 electrode sheet, 7 finger, 10, 20 touch switches, 11 protrusion, 12 screw hole, 21 electrode, 22 light emitting element, 31 claw, 32 screw through hole, 33 lens through hole, 51 operation surface, 52 mark.

Claims

【Claim 1】 A case, a circuit board housed inside the case and having electrodes for detecting a change in capacitance patterned on its surface, a light guide lens made of a dielectric having light transmissibility and elasticity, disposed on the surface of the electrodes such that its lower surface directly contacts the electrodes, an operation panel that directly contacts the upper surface of the light guide lens and is fixed to the case so as to press the light guide lens toward the circuit board, and has an operation surface for performing an operation by a user bringing a finger close, a light emitting element mounted on the circuit board so as to be disposed on the side of the light guide lens, and irradiating light toward the side surface of the light guide lens, a housing fixed to the case, and a through-hole for the lens is formed in the housing, the light guide lens is disposed in the through-hole for the lens, a light diffusing agent is dispersed and disposed in the light guide lens, and a capacitive touch switch, characterized in that part of the light incident from the light emitting element to the side surface of the light guide lens is emitted from the upper surface of the light guide lens toward the operation surface.

Images