JP2014154318A - Touch switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a touch switch capable of easily securing an optical path.SOLUTION: A touch switch 1 includes: a light emitting element 4; a touch sensor part 5 having a plurality of electrodes for object detection; a substrate 6 provided with the light emitting element 4 and the touch sensor part 5 on the same surface thereof; and a translucent member 3 covering the light emitting element 4, the touch sensor part 5 and the substrate 6 by transfer molding. The translucent member 3 is configured as a light guide part for guiding light emitted from the light emitting element 4 to an emission surface disposed to face the touch sensor part 5.

Description

  The present invention relates to a touch switch, and more particularly to a touch switch having a backlighting function.

  As an example of the operation input device provided in the electronic apparatus, for example, an operation input device including a capacitance detection type touch input sensor has been proposed (for example, see Patent Document 1).

  In the conventional operation input device described in Patent Document 1, a plurality of touch input sensors are arranged on the touch pad operation surface. As the touch input sensor, a capacitance detection type sensor is used in which a horizontal electrode surface and a vertical electrode surface are overlapped to detect a touch operation from a change in charge capacity. A hole is formed in the touch pad corresponding to each of the plurality of touch input sensors.

  On the back side of the touch input sensor, a light emitting element is attached to each of the plurality of holes, and a light guide plate is attached so as to block all the holes. Since the light emitted from each light emitting element is guided to the hole corresponding to each light emitting element by the light guide plate, the positions of the plurality of touch input sensors are displayed by the light emitting elements.

JP 2006-146701 A

  The conventional operation input device described in Patent Document 1 has a configuration in which the position of the touch input sensor is caused to emit light by a light emitting element disposed on the back side of the touch input sensor. Because of the structure, the electrode formation region of the touch input sensor serves as a light path. Therefore, it is necessary to form a hole in the electrode formation region so as not to block the light path.

  Not only the electrodes but also the driving parts of the light emitting elements need to be arranged so as not to block the light path from the light emitting elements to the touch pad operation surface, so the degree of freedom of component arrangement is low.

  Accordingly, an object of the present invention is to provide a touch switch that can easily secure a light path.

[1] The present invention provides a light emitting element, a touch sensor unit having a plurality of electrodes for object detection, a substrate on which the light emitting element and the touch sensor unit are provided on the same surface, the light emitting element, and the touch sensor. And a translucent member that covers the substrate with a transfer mold, and the translucent member serves as a light guide unit that guides light from the light emitting element to a surface facing the mounting surface of the substrate. The touch switch is characterized by being configured.

[2] The translucent member according to the above [1] has a partially exposed coating layer or printed layer, and the exposed part of the coated layer or the printed layer is light from the light emitting element. It is comprised as a design area | region illuminated by this, It is characterized by the above-mentioned.

[3] The touch sensor unit according to [1] is configured by a capacitive electrode having a detection electrode and a drive electrode.

  According to the present invention, it is possible to easily secure a light path, and the degree of freedom in design can be improved.

It is a cross-sectional schematic diagram for demonstrating the structural example of the touch switch which concerns on typical embodiment of this invention. It is a perspective schematic diagram for demonstrating one structural example of a touch switch. It is (a)-(d) figure for demonstrating an example of the method of shape | molding the light guide part in a touch switch.

  Preferred embodiments of the present invention will be specifically described below with reference to the accompanying drawings. In the figure according to this embodiment, the ratio of the parts constituting the touch switch is exaggerated, unlike the actual one.

(Overall configuration of touch switch)
1 and 2, reference numeral 1 indicating the whole schematically shows an example of a typical touch switch according to this embodiment. The touch switch 1 is not particularly limited, but for example, an operation for a vehicle that outputs an operation signal for controlling the operation of an in-vehicle device such as an air conditioner, an audio device, a navigation device, an air conditioner device, and a communication device. It is applied as an input device.

  As shown in FIGS. 1 and 2, the touch switch 1 includes a resin touch panel (touch pad) 2 having a planar operation surface 2a in the form of a film, a sheet, or a plate as an illumination target part. ing. The touch panel 2 is a known touch sensor that performs a touch input operation of an in-vehicle device. Examples of the touch sensor include a capacitance type sensor and a pressure sensitive sensor.

  As shown in FIGS. 1 and 2, the external appearance of the touch panel 2 constitutes a rectangular light guide 3 that is a translucent light guide that guides light to the operation surface 2 a. Inside the light guide 3, a light emitting element 4 as a light source for backlight and a touch sensor unit 5 are mounted on the same surface of a substrate 6 made of an insulating wiring substrate.

  On the surface of the light guide 3 that faces the mounting surface of the substrate 6, as shown in FIGS. 1 and 2, for example, a light-shielding coating layer 7 that is coated is formed. The coating layer 7 is formed with a light-transmitting display portion 7a by peeling off the coating corresponding to the display shape by laser cutting.

  The extraction display portion 7a is configured as a design area that is transmitted and illuminated by the light from the light emitting element 4, and is composed of characters, numbers, figures, symbols, designs, or the like. Instead of the coating layer 7, a configuration in which a light-shielding printing layer subjected to silk printing is formed except for a portion corresponding to the display shape, or a configuration in which the display portion 7 a is formed in the printing layer by laser cutting is adopted. can do. Further, it is possible to adopt a configuration in which the cut-out display portion 7a is formed on the back surface of the light guide 3 facing the mounting surface of the substrate 6.

  As an example of the touch sensor unit 5, for example, a plurality of strip-shaped or linear X electrodes wired along the X direction and a plurality of strip-shaped or linear wires wired along the Y direction intersecting the X electrodes. The two electrodes (detection electrode and drive electrode) with the Y electrode are combined so as not to contact each other, or the two comb-shaped electrodes (detection electrode and drive electrode) are engaged so as not to contact each other. is there. Electrical signals can be taken out via wirings, electrode terminals, etc. (not shown) connected to these electrodes.

  As these electrodes, for example, a general conductive material such as a metal such as gold, silver, copper, and aluminum, or a conductive metal oxide such as transparent ITO (indium oxide) is used. A conductive pattern is formed by applying or printing a conductive film such as metal plating or conductive paste in a required shape. It is also possible to form a conductive pattern by vapor deposition or sputtering.

  The substrate 6 is further provided with a circuit component (not shown) for causing the light emitting element 4 to emit light. As the substrate 6, a general constituent material can be used. Moreover, as the light emitting element 4, for example, a side-emitting light source is suitable.

(Configuration of light guide)
In the touch switch 1 according to this embodiment, the touch panel 2 in which the light-emitting element 4 and the touch sensor unit 5 are collectively sealed with the touch sensor substrate 6 provided on the same mounting surface is a light guide unit. The main structure is the point formed as the guide 3.

  The light guide 3 is preferably formed, for example, by transfer molding or compression molding using a thermosetting resin having translucency. Thermosetting resins are preferred because they have good fluidity when filled in the mold and can reduce the deformation of circuit components. As a thermosetting resin which is a constituent material of the light guide 3, for example, a general thermosetting resin such as an epoxy resin type, a phenol resin type, a melanin resin type or a urea resin can be used.

(Light guide molding method)
The light guide 3 according to the illustrated example can be effectively formed by a regular transfer molding using a thermosetting resin for forming a light guide.

  In the transfer molding of the light guide 3 made of a thermosetting resin, first, as shown in FIG. 3A, a primary molded product including a substrate 6 on which the light emitting element 4 and the touch sensor unit 5 are mounted is prepared. .

  As shown in FIG. 3B, the substrate 6 is clamped between a pair of molding dies 101 and 102 heated to a predetermined molding temperature. Subsequently, the liquid thermosetting resin 105 is pushed out into the cavities 103 of the pair of molding dies 101 and 102 by the operation of the plunger 104.

  The thermosetting resin 105 extruded at a predetermined molding pressure by the plunger 104 is filled into the cavities 103 of the pair of molding dies 101 and 102 through a runner gate (not shown).

  Subsequently, the thermosetting resin 105 is thermoset by waiting for a predetermined molding time. Thereafter, the thermosetting resin 105 that has been thermoset is released from the pair of molding dies 101 and 102. Thereby, a secondary molded product encapsulated with the thermosetting resin 105 for forming the light guide is obtained.

  Next, as shown in FIGS. 3C and 3D, the light-shielding coating layer 7 is formed by coating the surface of the thermosetting resin 105 of the secondary molded product. The portion corresponding to the display shape of the coating layer 7 is peeled off by laser cutting to form a light-transmitting removal display portion 7a. Through the above steps, the light guide 3 that guides the light from the light emitting element 4 to the surface of the touch panel 2 facing the mounting surface of the substrate 6 is obtained.

(Effect of embodiment)
By employing the touch switch 1 according to this embodiment, the following effects can be obtained in addition to the above effects.

(1) It is not necessary to provide an opening in the electrode of the touch sensor unit 5, the substrate 6, or the like, and the entire touch switch 1 can be reduced in size and thickness.
(2) Since the light emitting element 4 can be arranged without forming the light path opening between the mounting surface of the substrate 6 and the operation surface 2a of the touch switch 1, the light path can be minimized.
(3) Since it is not necessary to form an opening for a light path in the electrode of the touch sensor unit 5 or the substrate 6, the area occupied by the electrode or wiring can be reduced and mounted on the substrate 6. The number of parts can be increased. As a result, the cost increase of the touch switch 1 can be suppressed.
(4) The touch panel 2 that enables back-lighting without forming a light path opening can be obtained with a simple configuration.
(5) The thickness dimension of the light guide 3 can be set thin, and the detection sensitivity can be increased.

[Modification]
Although the touch switch of the present invention has been described based on the above-described embodiment and the illustrated examples, the present invention is not limited to the above-described embodiment and the illustrated example, and various modes can be used without departing from the gist thereof. Can be implemented.

  An uneven portion or a diffusion layer for diffusing and emitting incident light may be provided between the light guide 3 and the coating layer 7, and a white paint is applied to the surface on the touch switch operation surface side of the substrate 6. A configuration or the like may be provided.

  As an application target of the light guide 3, in addition to various in-vehicle devices installed around the driver's seat of the vehicle, for example, an input operation unit of various electronic devices such as push switches and portable terminals, and an illumination target unit such as a liquid crystal panel It can be used suitably.

  As is clear from the above description, not all the combinations of the features described in the above-described embodiments, modifications, and illustrated examples are necessarily essential to the means for solving the problems of the present invention. It should be noted.

DESCRIPTION OF SYMBOLS 1 ... Touch switch, 2 ... Touch panel, 2a ... Operation surface, 3 ... Light guide, 4 ... Light emitting element, 5 ... Touch sensor part, 6 ... Substrate, 7 ... Paint layer, 7a ... Unplug display part, 101, 102 ... Molding Mold 103, cavity, 104 plunger, 105 thermosetting resin

Claims (3)

A light emitting element;
A touch sensor unit having a plurality of electrodes for object detection;
A substrate in which the light emitting element and the touch sensor unit are provided on the same surface;
A translucent member in which the light emitting element, the touch sensor unit and the substrate are covered with a transfer mold;
With
The touch switch, wherein the translucent member is configured as a light guide unit that guides light from the light emitting element to a surface facing the mounting surface of the substrate. The translucent member has a paint layer or a print layer with a part exposed,
The touch switch according to claim 1, wherein an exposed part of the coating layer or the printed layer is configured as a design region that is transmitted and illuminated by light from the light emitting element.   The touch switch according to claim 1, wherein the touch sensor unit includes a capacitive electrode having a detection electrode and a drive electrode.

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