JP2018106985A - Capacitive touch switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a capacitive touch switch capable of reliably operating a touch switch to be operated by an operator without making a mistake. SOLUTION: A switch circuit board 40 in which a transparent switch pattern 43 is formed on a transparent board 41, and a light source mounted on a lower side of the switch circuit board 40 and a light source 13 mounted at a position facing the switch pattern 43. The capacitance that changes according to the approach distance when the substrate 10 and the switch pattern 43 are approached by a finger or the like (conductor) is detected, and it is detected that the finger is approaching the switch pattern 43 to a predetermined approach distance. At that time, the light source 13 corresponding to the switch pattern 43 is blinked or gradually turned on, and when it is detected that the finger is closer to the switch pattern 43, the light source 13 corresponding to the switch pattern 43 is turned on. Equipped. [Selection diagram] Fig. 1

Description

  The present invention relates to a capacitive touch switch that operates by utilizing a change in capacitance when a conductor such as a human body approaches a switch pattern.

  Conventionally, a capacitive touch switch that detects on / off of a switch by utilizing a change in capacitance between the switch pattern and the ground (earth) when a conductor (such as a finger) approaches the switch pattern. Is being used. Among this type of capacitive touch switch, an illuminated capacitive touch switch in which an illuminating means for illuminating from the back side is installed is also used.

  For example, as shown in Patent Document 1, the capacitive touch switch guides light emitted from a light source mounting substrate (substrate) (4) having a light source (5) mounted on the upper surface and the light source (5) upward. A transparent plate (2), a switch circuit board (electrode plate) (1) on which a switch pattern (electrode part) (C) is formed, and a film (6) on which punched letters are formed are laminated in this order. Configured. If the finger touches the film (6), the capacitance between the switch pattern (C) formed on the switch circuit board (1) and the ground changes, and the change is placed on the light source mounting board (4). The light source (5) is turned on at the same time as the switch-on signal is transmitted.

  On the other hand, when the light source (5) is turned on, the light from the light source (5) passes through the transparent plate (2) and the switch circuit board (1), illuminates the film (6), and is formed on the film (6). Light is emitted upward from the extracted character portion.

  By the way, although the above-mentioned patent document 1 shows an example in which one switch pattern (C) is installed on one switch circuit board (1) to form one touch switch, Capacitive touch that is formed on the same switch circuit board (1), and turns on only the touch switch when the operator's finger touches any touch switch and lights only the touch switch. Switches are also commonly used.

Japanese Unexamined Patent Publication No. 04-92330

  However, when multiple touch switches are arranged close to each other, the operator may accidentally operate the adjacent touch switch even though he intends to touch his intended touch switch. .

  The present invention has been made in view of the above points, and an object of the present invention is to provide a capacitive touch switch that can reliably operate a touch switch to be operated by an operator without making a mistake. is there.

A capacitive touch switch according to the present invention includes a switch circuit board in which a transparent switch pattern is formed on a transparent board, and a light source mounted at a position opposite to the switch pattern, which is installed below the switch circuit board. The capacitance changing according to the approach distance when the conductor approaches the light source mounting board and the switch pattern is detected, and it is detected that the conductor has approached the switch pattern to a predetermined approach distance. At the time, the light source corresponding to the switch pattern blinks or is gradually turned on, and when it is detected that the conductor is closer to the switch pattern, the control unit that turns on the light source corresponding to the switch pattern, It is characterized by comprising.
When the conductor approaches, the approaching switch pattern blinks or is gradually lit by the light source placed below it, so the touch switch that is to be operated (touched) is the touch switch that is intended for operation. It can be easily noticed before touching. Therefore, even when a plurality of touch switches are adjacent to each other, the touch switch intended by the operator can be reliably operated.
In particular, in the case of the present invention, when the touch switch is approached, the touch switch flashes or gradually turns on, so the eye-catching stimulus given to the eyes is stronger than when it is simply turned on, so let's touch more effectively. It is possible to make the operator recognize the touch switch.

Further, the present invention is characterized in that a backlight light source is mounted on the light source mounting substrate, and a backlight switch pattern for turning on and off the backlight light source is provided on the switch circuit substrate.
Thus, each touch switch can be illuminated in advance before operating the touch switch, and the operator can more easily grasp the position of each touch switch. If the color of the light source for backlight is different from the color of the light source, the difference between the two can be recognized more reliably, which is more suitable for the operator.

According to the present invention, when the light source for the backlight is turned on when the controller turns on the light source corresponding to the switch pattern when the conductor approaches the switch pattern, The light source is turned off.
This makes it easier to select by touching the backlight of multiple touch switches before selecting the switch you want to touch, and turning off the backlight after touching and selecting the switch you want to touch. Only the touch switch that has been touched can be lit brightly, and it can be clearly shown that the touch switch has been selected.

  ADVANTAGE OF THE INVENTION According to this invention, the touch switch which an operator is going to operate can be operated reliably without making a mistake.

1 is an exploded schematic cross-sectional view of a capacitive touch switch 1. FIG. 1 is a schematic cross-sectional view of a capacitive touch switch 1. FIG. 5 is an operation flowchart of the capacitive touch switch 1.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an exploded schematic cross-sectional view of a capacitive touch switch 1 according to an embodiment of the present invention. As shown in the figure, the capacitive touch switch 1 includes a light source mounting substrate 10 having a light source 13 and a backlight light source 15 mounted on the upper surface, a case 20 placed on the light source mounting substrate 10, and a case 20 The switch circuit board 40 placed on the switch circuit board 40 via the double-sided adhesive sheet 70, the design board 80 placed on the switch circuit board 40 via the double-sided adhesive sheet 70, the switch circuit board 40 and the light source mounting board 10 And a control unit 100 electrically connected to the control unit 100. In the following description, “upper” refers to the direction of viewing the switch circuit board 40 from the light source mounting board 10, and “lower” refers to the opposite direction. In the present invention, “transparent” includes translucent (a state in which light is transmitted but not completely transparent).

  The light source mounting substrate 10 includes a plurality of pairs of a plurality of light sources 13 and a plurality of backlight light sources 15 on a hard substrate 11 made of a non-translucent (or translucent) material. Installed and configured. In this embodiment, a light emitting diode (LED) is used as the light source 13 and the backlight light source 15. In this embodiment, the color of light emitted from the light source 13 is different from the color of light emitted from the backlight light source 15. The light emitted from the light source 13 is configured to be brighter than the light emitted from the backlight light source 15. Various other circuit patterns (not shown) are also formed on the substrate 11.

  The case 20 is a synthetic resin molded product made of a non-translucent material (may be translucent), has a predetermined thickness, and faces the light source 13 and the backlight light source 15. A through hole 21 penetrating vertically is provided at a position. In the figure, the through hole 21 is also provided at a position facing the backlight switch pattern 45 described below, but the through hole 21 may be omitted.

  The double-sided adhesive sheet 30 has substantially the same shape as the upper surface of the case 20, and a through hole 31 having substantially the same shape is provided at a position facing each through hole 21.

  The switch circuit board 40 is configured by forming a plurality (three in FIG. 1) of switch patterns 43 and one backlight switch pattern 45 at predetermined positions on the lower surface of a substrate (transparent substrate) 41. . The substrate 41 is a transparent synthetic resin film having flexibility. Each switch pattern 43 and backlight switch pattern 45 is formed by printing (screen printing or the like) and drying a transparent conductive ink. A wiring pattern is connected to each switch pattern 43 and the backlight switch pattern 45 and is electrically connected to the control unit 100. The wiring pattern is formed using a normal opaque conductive ink, but may be formed using a transparent conductive ink. Examples of the opaque wiring pattern include a silver pattern and a copper pattern. Transparent resist layers 47 and 49 for covering the switch pattern 43 and the backlight switch pattern 45 are formed on the surfaces of the switch pattern 43 and the backlight switch pattern 45, respectively. The switch pattern 45 is protected. The resist layers 47 and 49 are formed by printing a transparent resist ink or the like, but may be formed by attaching a resist film. It is preferable to form a resist layer also on the wiring pattern other than the switch pattern 43 and the backlight switch pattern 45.

  The double-sided adhesive sheet 70 is configured by forming a transparent adhesive layer on the upper and lower surfaces of a transparent sheet.

  The design plate 80 is configured by forming a light shielding layer 81 having a desired shape on the lower surface of a flexible transparent synthetic resin substrate (flexible substrate) 85. The substrate 85 may be transparent so that the bottom can be seen through, but may be translucent by applying a color paint such as white to the extent that light is transmitted. The material of the substrate 85 itself may be translucent. A portion of the design plate 80 where the light shielding layer 81 is not provided becomes a light transmitting portion 83 that transmits light. The light shielding layer 81 is black in this example, but may be various other colors. In this example, the transparent (or translucent) substrate 85 is used, but instead, a substrate that is a half mirror that transmits light from below but reflects light from above may be used. .

  In order to assemble this capacitive touch switch 1, the double-sided adhesive sheet 70 is attached to the lower surface of the design plate 80, and the switch circuit board 40 is attached to the lower surface. Next, the double-sided adhesive sheet 30 is attached to the lower surface of the switch circuit board 40, and the case 20 is attached to the lower surface. Then, the light source mounting substrate 10 is attached to the lower surface of the case 20 with a double-sided adhesive sheet (not shown) (the same sheet as the double-sided adhesive sheet 30). For bonding between the members, an adhesive may be used instead of the double-sided adhesive sheet, or other mechanical fixing means may be used. The above assembling procedure is an example, and it goes without saying that the assembly may be performed using other various assembling procedures.

  FIG. 2 is a schematic cross-sectional view of the capacitive touch switch 1 configured as described above. As shown in the figure, each switch pattern 43 is installed at a position facing each light source 13 and backlight light source 15. Each switch S1 is constituted by each switch pattern 43, the light source 13, the backlight light source 15, and a design plate 80 covering the switch pattern 43, and the backlight switch pattern 45 and the design plate 80 covering the top. Thus, the backlight switch S2 is configured.

  Returning to FIG. 1, the control unit 100 is connected (electrically connected, the same applies hereinafter) to the wiring patterns drawn out from the switch patterns 43 and the backlight switch pattern 45 of the switch circuit board 40. The control unit 100 may be formed on the switch circuit board 40, may be formed on the light source mounting board 10, may be formed on both boards, or may be formed on another board. It may be formed. The control unit 100 is connected to each of the switch patterns 43, detects a detection value corresponding to the capacitance of each switch pattern 43 (capacitance with respect to the ground, the same applies hereinafter), determines the change thereof, and further performs control. Capacitance detection determination control unit 110 that outputs a signal, and lighting, blinking, and extinguishing of each light source 13 by a control signal corresponding to the detection value of each switch pattern 43 determined by the capacitance detection determination control unit 110 And the switch light source driving unit 120 for detecting the detection value corresponding to the capacitance of the backlight switch pattern 45, determining the change, and outputting the control signal. And a control signal corresponding to the detection value of the backlight switch pattern 45 determined by the capacitance detection determination control unit 130. The backlight light source driving unit 140 to perform the lighting and extinguishing of the backlight light source 15 is configured by including a Te.

  The capacitance detection determination control unit 110 detects the detection value according to the capacitance between each switch pattern 43 and the ground (ground) separately (measurement), and the detection. A first comparator for comparing a detected value with a first reference value; a second comparator for comparing the detected detected value with a second reference value; and a switch based on a comparison result by the first and second comparators. And an output control circuit that outputs a control signal to the light source driving unit 120. The switch light source driving unit 120 is a circuit that supplies light source driving power to the light source 13 in accordance with a control signal from the capacitance detection determination control unit 110. The first reference value is a detection value when a finger (conductor (ground), hereinafter the same) approaches the switch pattern 43 to a predetermined position (a position away from the design plate 80 by a predetermined distance). The reference value is a detection value when the finger reaches the switch pattern 43 to a predetermined position (a position at which the design plate 80 is touched) closer to the predetermined position. Further, when detecting that the second comparator exceeds the second reference value, the capacitance detection determination control unit 110 converts the signal as a switch signal (switch-on signal), Also output to the capacity detection determination control unit 130.

  Specifically, when the finger is not approaching the position facing any one of the switch patterns 43 on the design plate 80, the detection value corresponding to the capacitance of the switch pattern 43 exceeds the first reference value. Accordingly, the light source driving power is not supplied from the switch light source driving unit 120 to the light source 13 corresponding to the switch pattern 43, and the switch S1 (see FIG. 2) is not illuminated. When the finger approaches a position close to any one of the switch patterns 43 on the design plate 80 up to a predetermined approach distance, the detection value corresponding to the capacitance of the switch pattern 43 exceeds the first reference value. The light source driving power is supplied from the switch light source driving unit 120 to the light source 13 corresponding to the switch pattern 43, and the switch S1 blinks (or gradually lights up). In addition, when the finger contacts a position on the design plate 80 that faces any one of the switch patterns 43, the detection value corresponding to the capacitance of the switch pattern 43 exceeds the second reference value. Light source driving power is supplied from 120 to the light source 13 corresponding to the switch pattern 43, and the switch S1 is lit. That is, when the first reference value is exceeded but the second reference value is not exceeded, light source driving power for blinking (or gradually turning on) the light source 13 is supplied, and when the second reference value is exceeded, the light source 13 The light source driving power for turning on the light is supplied.

  The capacitance detection determination control unit 130 determines a detection value detected by a capacitance detection circuit that detects (measures) a detection value corresponding to the capacitance between the backlight switch pattern 45 and the ground. A comparator for comparing with the reference value for output, and an output control circuit for outputting a control signal to the light source driving unit for backlight 140 based on the comparison result by the comparator. The backlight light source driving unit 140 is a circuit that supplies light source driving power corresponding to a control signal from the capacitance detection determination control unit 130 to all the backlight light sources 15 at the same time. The determination reference value is a detection value when the finger reaches the backlight switch 45 to a predetermined position (position where the design plate 80 is touched), and corresponds to the second reference value.

  Specifically, when the finger is not close to the position facing the backlight switch pattern 45 on the design plate 80, the detection value corresponding to the capacitance of the backlight switch pattern 45 is the determination reference value. Therefore, no light source driving power is supplied from the backlight light source driving unit 140 to each backlight light source 15, and the backlight light source 15 is turned off. On the other hand, when the finger touches the position on the design plate 80 facing the backlight switch pattern 45, the detection value corresponding to the capacitance of the backlight switch pattern 45 exceeds the determination reference value. Light source driving power is supplied from the light source driving unit 140 to all the light sources 15, and all the switches S 1 are illuminated by the light sources 15. Further, when a switch signal is input from the capacitance detection determination control unit 110, control is performed to turn off all the light sources 15 that have been turned on.

  FIG. 3 is an operation flowchart showing an example of the operation of the capacitive touch switch 1. In the figure, when a finger touches the design plate 80 on the backlight switch S2, the backlight switch S2 is turned on (step ST1), all the backlight light sources 15 are turned on, and each switch S1 is turned on. Illuminated by the light (step ST2). On the other hand, when the backlight switch S2 is off, the backlight light source 15 remains off and the process proceeds to step ST3.

  Next, when the finger approaches the design plate 80 on the desired switch S1 up to a predetermined separation distance (step ST3), the switch light source 13 blinks (or gradually turns on), and the switch S1 blinks (or flashes) (or Illumination is performed so as to light up gradually (step ST4).

  Then, when the finger contacts the design plate 80 on the desired switch S1 (step ST5), the switch light source 13 is turned on and the switch S1 is illuminated (step ST6).

  At this time, if the backlight is turned on, the illumination by the backlight of all the switches S1 is stopped by turning off all the light sources 15 for the backlight (step ST7). As a result, only the switch S1 that is turned on (touched) is illuminated brightly.

  On the other hand, in steps ST3 and ST4, the finger approaches the design plate 80 on the desired switch S1 to a predetermined separation distance, and the switch S1 is in the state of blinking illumination (or illumination so that it gradually turns on). Thereafter, when the finger does not further approach the switch S1 and the switch S1 moves away from the blinking position, the process proceeds to step ST8, the switch light source 13 is turned off, and the illumination of the switch S1 is stopped. .

  In the above example, the detection value when the finger touches the design plate 80 on the switch S1 is used as the second reference value. However, the detection value at the position before the finger touches the design plate 80 (immediately before). If the second reference value is used, the switch S1 can be turned on without touching the finger.

  As described above, according to the capacitive touch switch 1, when the finger approaches, the approaching switch S1 (switch pattern 43) is blinked or gradually turned on by the light source 13 disposed thereunder. Therefore, it is possible to easily recognize whether or not the switch S1 (switch pattern 43) to be operated (touched) is the switch S1 (switch pattern 43) intended to be operated before touching. Therefore, even when a plurality of switches S1 (switch pattern 43) are adjacent to each other, the switch S1 (switch pattern 43) intended by the operator can be reliably operated.

  In particular, when the finger approaches the switch S1 (switch pattern 43), the switch S1 (switch pattern 43) flashes or gradually lights up. The operator can recognize the switch S <b> 1 (switch pattern 43) that is strong and more effective to touch.

  In the capacitive touch switch 1, the backlight light source 15 is mounted on the light source mounting substrate 10, and the backlight switch pattern 45 for turning the backlight light source 15 on and off is provided on the switch circuit substrate 40. Therefore, each switch S1 (switch pattern 43) can be illuminated in advance before operating the switch S1, and the operator can more easily grasp the position of each switch S1 (switch pattern 43). . Further, since the color of the backlight light source 15 and the color of the light source 13 are made different, the difference between the two can be recognized more reliably, which is more suitable for the operator.

  In the capacitive touch switch 1, when the light source 13 corresponding to the switch S 1 (switch pattern 43) is turned on when the finger approaches the switch S 1 (switch pattern 43), the backlight light source 15. When is turned on, the backlight light source 15 is turned off. Therefore, before selecting the switch S1 to be operated, the backlights of the plurality of switches S1 (switch pattern 43) are turned on. Thus, after selecting the switch S1 to be operated easily, the backlight is turned off, so that only the operated switch S1 can be lit brightly, and it can be clearly shown that the switch S1 has been selected.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea described in the claims and the specification and drawings. Is possible. Note that any shape, structure, or material not directly described in the specification and drawings is within the scope of the technical idea of the present invention as long as the effects and advantages of the present invention are exhibited. For example, the light source and the backlight light source are not limited to light emitting diodes, and may be various other light sources as long as they emit light. Further, the light source mounting board and the switch circuit board may be formed of a hard board or a flexible circuit board. When both the substrates are constituted by flexible circuit boards, the two substrates can be formed on one flexible circuit board, and can be arranged vertically by folding back the connecting portion that connects the two boards. In the above embodiment, the backlight light source provided corresponding to each switch is turned on / off at the same time. However, the backlight light source may be turned on / off individually for each switch. Further, the backlight light source may be installed not for each switch but for one of a plurality of switches. The backlight switch for turning on and off the backlight light source is not necessarily provided on the same substrate (switch circuit board) as the touch switch for turning on and off the light source, and may be provided on a separate substrate. Further, the backlight switch is not necessarily a capacitive touch switch, and a mechanical switch such as a tact switch may be used. Further, the backlight switch may also serve as a power switch of a device on which the capacitive touch switch according to the present invention is mounted. Further, in the present invention, it is not always necessary to install a backlight light source. Further, the backlight may not be turned off when any one of the switches is turned on. Further, various conductors other than the finger may be brought close to the switch or the backlight switch. Moreover, you may comprise so that a light source or the light source for backlights may light up in the state which the finger | toe did not touch a design board. In the above example, a design plate is provided, but the design plate may be omitted or replaced with another member such as a resist layer.

  Moreover, as long as there is no contradiction in the objective, a structure, etc., the embodiment shown by the said description and each figure can combine the description content of each other. In addition, the above description and the description of each drawing can be an independent embodiment even if it is a part of it, and the embodiment of the present invention is an embodiment in which the above description and each drawing are combined. It is not limited to.

DESCRIPTION OF SYMBOLS 1 Capacitive touch switch 10 Light source mounting board 13 Light source 15 Backlight light source 20 Case 30 Double-sided adhesive sheet 40 Switch circuit board 41 Board (transparent board)
DESCRIPTION OF SYMBOLS 43 Switch pattern 45 Backlight switch pattern 70 Double-sided adhesive sheet 80 Design board 100 Control part 110 Capacitance detection judgment control part 120 Switch light source drive part 130 Capacitance detection judgment control part 140 Backlight light source drive part S1 Switch (Touch switch)
S2 Backlight switch (backlight touch switch)

Claims (3)

A switch circuit board in which a transparent switch pattern is formed on a transparent board;
A light source mounting board installed on the lower side of the switch circuit board and mounted with a light source at a position facing the switch pattern;
The capacitance that changes according to the approach distance when a conductor approaches the switch pattern is detected, and when it is detected that the conductor has approached the switch pattern to a predetermined approach distance, When the corresponding light source blinks or is gradually turned on, and when it is detected that the conductor is closer to the switch pattern, a control unit that turns on the light source corresponding to the switch pattern;
A capacitive touch switch characterized by comprising: The capacitive touch switch according to claim 1,
While mounting a light source for backlight on the light source mounting substrate,
A capacitive touch switch, wherein a backlight switch pattern for turning on and off the backlight light source is provided on the switch circuit board. The capacitive touch switch according to claim 2,
When the light source corresponding to the switch pattern is turned on when the conductor approaches the switch pattern and the light source for the backlight is turned on, the control unit turns off the light source for the backlight. Capacitive touch switch characterized by that.

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