WO2007132817A1

WO2007132817A1 - Input device having illuminating function

Info

Publication number: WO2007132817A1
Application number: PCT/JP2007/059882
Authority: WO
Inventors: Tsuyoshi Hayama; Shozo Takamura; Manabu Shimaoka; Hisato Shimomura
Original assignee: Alps Electric Co., Ltd.
Priority date: 2006-05-16
Filing date: 2007-05-14
Publication date: 2007-11-22

Abstract

Provided is an input device having an illuminating function, which can be manufactured at a low price and in a small size and which has a low power consumption. The input device having the illuminating function is constituted to comprise a wiring board (1) having a desired wiring pattern (1a) formed thereon, light emitting diodes (2) mounted on the wiring board (1), a light guide plate (4) for guiding the lights emitted from the light emitting diodes (2) in a planar direction, stationary contacts (or conductive posts) (5) disposed on the light guide plate (4) for pushing switches, metal domes (or movable contacts) (6) for switching the stationary contacts into conductive or inconductive states, and a cover sheet (8) equipped with actuators (7) for pushing and operating the metal domes (6). In the surface of the light guide plate (4), there are formed step portions (9) having bottom faces (9a) for housing the metal domes (6).

Description

Specification

Input device with illumination function

Technical field

TECHNICAL FIELD [0001] The present invention relates to an input device with an illumination function provided in a mobile phone or the like, and more particularly, to a configuration of a light guide plate that guides light emitted from a light emitting diode in a surface direction of the input device. Background art

Conventionally, as this type of input device with illumination function, as shown in FIG. 5, a printed circuit board 101 on which a required wiring pattern including a fixed contact of a push button switch is formed, and one side of the printed circuit board 101 The light guide member 102 disposed in the light guide, the plurality of light emitting diodes 103 disposed on the side surface of the light guide member 102, and the cavity (through hole) 104 provided in the light guide member 102 are accommodated in the printed circuit board. A domed metal panel contact 105 constituting the movable contact of the push button switch mounted on the surface of 101, an elastic sheet 107 having a protrusion 106 formed on a portion facing the domed metal panel contact 105, and an elastic sheet 107 There is known one provided with a transparent or colored translucent push button portion 108 provided at a portion corresponding to the projection 106 on the outer surface (see, for example, Patent Document 1).

[0003] According to this input device with an illumination function, the light emitted from the light emitting diode 103 is guided to the vicinity of the push button portion 108 by the light guide member 102 and is emitted in the cavity 104. Therefore, the elastic sheet 107 and The operation surface of the push button unit 108 can be illuminated by the light emitted through the push button unit 108.

Patent Document 1: Japanese Unexamined Patent Application Publication No. 2004-356028

Disclosure of the invention

Problems to be solved by the invention

However, in the input device with an illumination function according to the known example, a large number of cavities (through holes) 104 are provided in the light guide member 102 for accommodating the domed metal panel contact 105. Therefore, in order to uniformly shine all the push button portions 108 that are difficult to uniformly guide the light emitted from one light emitting diode 103 over a wide range, it is inevitably necessary that a plurality of (in the above-described known example, 6 Light emitting diodes). Therefore, the number of parts and assembly As the number of man-hours increases, the manufacturing cost of the device becomes expensive, the device becomes larger, the power consumption is large!

[0005] Note that if an EL (electric aperture luminescence) element is used as a light emitter instead of the configuration using the light guide member 102 and the light emitting diode 103, all the push button portions 108 can be illuminated uniformly. However, EL devices are expensive, generate electromagnetic noise, and have low reliability for long-term use. Furthermore, since the upper force of the EL element also operates the contact part, the operational feeling of the push button part 10 8 deteriorates, and the EL element is more likely to deteriorate.

[0006] The present invention has been made in order to solve the deficiencies in the prior art, and the object of the present invention is to provide an input device with an illumination function that can be manufactured inexpensively and in a small size with low power consumption. I will.

Means for solving the problem

[0007] In order to solve the above-described problems, the present invention firstly includes an input device with an illumination function, a wiring board on which a required wiring pattern is formed, a light emitting diode mounted on the wiring board, A light guide plate that guides light radiated from the light emitting diode in a plane direction, a fixed contact of a push button switch that is provided on the light guide plate and is electrically connected to the wiring pattern; A metal dome that is a movable contact of the push button switch that switches between the plurality of fixed contacts between a conductive state and a non-conductive state; and a cover sheet provided with an actuator for pressing the metal dome. A bottom surface for guiding the light emitted from the light emitting diode in the surface direction is formed in the setting portion of the metal dome in the light plate. In this way, when the bottom surface is formed in the setting portion of the metal dome in the light guide plate, the light emitted from the light emitting diode through the bottom surface portion can be guided in the direction of the surface of the light guide plate. Light can be uniformly guided to the entire surface of the light plate, and the number of light emitting diodes can be reduced.

[0008] In addition, according to the present invention, secondly, in the input device with an illumination function of the first configuration, a conductive post penetrating a surface force rear surface of the light guide plate is used as the fixed contact, and the wiring board and the guide The wiring pattern and the fixed contact are electrically connected by closely contacting the optical plate. According to the construction, a through hole is formed in the light guide plate Therefore, it is not necessary to use a complicated manufacturing method such as making a light guide plate, and thus an input device with an illumination function can be manufactured at a low cost, and the wiring pattern and the light guide plate can be simply adhered to each other. Since the fixed contact can be electrically connected, the electrical connection between the wiring pattern and the fixed contact can be easily performed, and the assembly of the input device with the illumination function can be facilitated.

[0009] In addition, according to the present invention, thirdly, in the input device with an illumination function of the first or second configuration, the wiring board is formed of a light-shielding white material. According to the cover structure, since the light emitted from the light emitting diode can be scattered on the surface of the wiring board formed of the light-shielding white material, the uniformity of the light irradiated to the cover sheet can be improved. it can.

[0010] Further, according to the present invention, fourthly, in the input device with an illumination function having the first to third configurations, the cover sheet is formed of a translucent white material. According to such a configuration, the light emitted from the light emitting diode can be scattered on the surface of the cover sheet formed of the translucent white material, so that the uniformity of the light irradiated on the cover sheet can be improved. it can.

[0011] Fifthly, according to the present invention, in the input device with an illumination function having the first to third configurations, the cover sheet is formed of a transparent material. According to the powerful configuration, the amount of light transmitted through the cover sheet can be increased, so that the brightness of the cover sheet can be increased. In addition, since the transparent material can be formed as thin as it is not necessary to contain the mixture in the resin, the input device can be formed thinner.

[0012] In addition, according to the sixth aspect of the present invention, in the input device with an illumination function having the first to third configurations, the cover sheet is formed of a transparent material and the surface thereof is subjected to light diffusion treatment. It was configured as follows. According to the powerful configuration, since the light emitted from the light emitting diode can be scattered on the surface of the cover sheet that has been subjected to the light diffusion treatment, the uniformity of the light irradiated to the cover sheet can be improved.

In addition, according to the present invention, seventhly, in the input device with an illumination function having the first to sixth configurations, the actuator is formed of a light-shielding white material. With this configuration, an input device with an illumination function that selectively illuminates the surrounding area of the actuator is provided. can get.

[0014] In addition, according to the present invention, eighthly, in the input device with an illumination function having the first to sixth configurations, the actuator is formed of a transparent material. By virtue of this configuration, an input device with an illumination function that illuminates the entire surface of the cover sheet including the setting portion of the actuator is obtained.

The invention's effect

[0015] According to the present invention, since the bottom surface for guiding the light emitted from the light emitting diode in the surface direction is formed in the setting portion of the metal dome in the light guide plate, the light is uniformly distributed on the entire surface of the light guide plate with a small number of light emitting diodes. The input device with illumination function can be reduced in size, cost, and power can be reduced by reducing the number of components.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of an input device with an illumination function according to the present invention will be described with reference to FIGS. 1 to 4. 1 is an exploded perspective view of an input device with an illumination function according to the embodiment, FIG. 2 is an exploded side view of the input device with an illumination function according to the embodiment, and FIG. 3 is an assembled state of the input device with an illumination function according to the embodiment. Sectional drawing and FIG. 4 are principal part sectional drawing of the light-guide plate which concerns on embodiment.

As shown in FIG. 1 to FIG. 3, the input device with an illumination function according to the embodiment is not shown with the terminal portion la!配線 Emitted from the light emitting diode 2 and the required mounting parts including the wiring board 1 on which the required wiring pattern including the wiring is formed, the side light emitting type light emitting diode 2 and the varistor 3 mounted on the wiring board 1 A light guide plate 4 that guides light in a plane direction, a plurality of sets of push button switches fixed on the light guide plate 4 and a set of fixed contacts 5 and a set of fixed contacts in a conductive state or a non-conductive state. It is mainly composed of a metal dome 6 for switching to a state and a cover sheet 8 provided with an actuator 7 for pressing the metal dome 6.

[0018] Although the wiring board 1 can be formed of any known insulating material belonging to the public knowledge, the light emitted from the light emitting diode 2 is scattered to improve the uniformity of the light irradiated on the cover sheet 8. It is particularly desirable to form with a light-shielding white material. This type of wiring board material includes reinforced plastics based on liquid crystal polymers and polyimide, Rigid systems such as glass epoxy and low-temperature fired ceramics can be used. The wiring board 1 can have a single-layer structure or a multi-layer structure as required. In addition, the surface of the wiring board formed of a non-white light-shielding material is covered with a white material.

The light guide plate 4 is formed of a highly transparent resin material such as acrylic resin, polycarbonate resin, or cyclic polyolefin resin, and each terminal portion formed on the wiring board 1 is formed on the upper surface thereof. A step portion 9 having a bottom surface 9a is formed at a position corresponding to la. The diameter of the step portion 9 is set to be slightly larger than the outer shape of the metal dome 6, and the depth of the step portion 9 is set to a total value of the height of the metal dome 6 and the height of the actuator 7. On the bottom surface 9a of the stepped portion 9, there are a plurality of (5 in the example of FIG. 1) conducting posts 5 as fixed contacts for the pushbutton switch at positions corresponding to the terminal portions la formed on the wiring board 1. Has been planted. As shown in an enlarged view in FIG. 4, the conductive post 5 is composed of a pin-shaped metal piece that penetrates from the upper surface to the lower surface of the bottom surface 9a, and the upper end surface and the lower end surface protrude from the upper surface and the lower surface of the bottom surface 9a, respectively. Set to do. Among the plurality of conductive posts 5, the conductive post 5 set at the center portion of the bottom surface 9a and the conductive posts 5 set at the peripheral portion of the bottom surface 9a are arranged non-conductive with each other. Note that the upper and lower end surfaces of the conductive post 5 are made of gold or silver as necessary to improve the electrical connection with the metal dome 6 and to improve wear resistance. You can also add a tag.

[0020] The metal dome 6 functions as a movable contact of the push button switch, and is formed by forming a metal plate, for example, a stainless steel plate into a circular shape. On the electrode contact side (inner surface side) of the metal dome 6, gold or silver is used as necessary to improve the electrical connection between the conductive posts 5 and to improve wear resistance. You can also add a tag.

[0021] The cover sheet 8 is formed with a resin film excellent in elasticity, such as polyethylene terephthalate. The cover sheet 8 can be formed of a translucent white material, can be formed of a transparent material whose surface is subjected to light diffusion treatment, or can be formed of a transparent material. When the cover sheet 8 is formed of a translucent white material and formed of a transparent material whose surface is subjected to light diffusion treatment, the light emitted from the light emitting diode 2 is scattered on the surface of the cover sheet 8. Because you can The uniformity of the light irradiated to the cover sheet 8 can be improved. On the other hand, when the cover sheet 8 is formed of a transparent material, the amount of light transmitted through the cover sheet 8 can be increased, so that the brightness of the cover sheet 8 can be increased.

The actuator 7 presses the metal dome 6 and is set at a position corresponding to the central portion of the step portion 11 formed on the light guide plate 4 on one side of the cover sheet 8. The actuator 7 can be formed of a light-shielding white material or a transparent material. When the actuator 7 is formed of a light-shielding white material, an input device with an illumination function that selectively illuminates the peripheral portion of the actuator can be obtained. On the other hand, when the actuator 7 is formed of a transparent material, an input device with an illumination function that illuminates the entire surface of the cover sheet 8 including the setting portion of the actuator 7 can be obtained.

[0023] The input device with illumination function of this example is assembled in the following procedure. That is, first, necessary mounting parts including the light emitting diode 2 and the varistor 3 are mounted at predetermined positions on the wiring board 1. In addition, a conductive post 5 which is a fixed contact of the push button switch is implanted in the light guide plate 4. In addition, the actuator 7 is attached to one side of the cover sheet 8 in the required arrangement. After the pressing force, the wiring board 1 and the light guide plate are assembled together in a state where the terminal portion la formed on the wiring board 1 and the conduction post 5 planted on the light guide plate 4 are in contact with each other. As a method of assembling the wiring board 1 and the light guide plate, adhesion or snap coupling can be used. As a result, the terminal portion la formed on the wiring board 1 is electrically connected to the conductive post 5 implanted in the light guide plate 4. Next, the metal dome 6 is housed in the stepped portion 9 of the light guide plate 4 with the upper side protruding. Finally, the cover sheet 8 is attached to the surface of the light guide plate while the actuator 7 is housed in the stepped portion 9.

[0024] In the input device with an illumination function of this example, the step portion 9 having the bottom surface 9a is formed on the light guide plate 4 as the storage portion of the metal dome 6, so that a small number of light emitting diodes (three in the example of FIG. ) Can uniformly guide light to the entire surface of the light guide plate 4, and by reducing the number of parts, it is possible to reduce the size, cost and power consumption of the input device with an illumination function.

In the input device with an illumination function of this example, the conductive post 5 penetrating from the front surface cover to the back surface of the light guide plate 4 is implanted in the light guide plate 4 as a fixed contact of the push button switch. And the light guide plate 4 are brought into close contact with each other so that the wiring pattern and the fixed contact can be electrically connected. It is possible to facilitate the electrical connection between the screen and the fixed contact, and as a result, the assembly of the input device with the illumination function can be facilitated.

[0026] In the above-described embodiment, the actuator 7 and the force sheet 8 formed separately are joined afterwards, but the gist of the present invention is not limited to this. For example, it is possible to use a cover sheet with an actuator obtained by injection molding.

Brief Description of Drawings

FIG. 1 is an exploded perspective view of an input device with an illumination function according to an embodiment.

FIG. 2 is an exploded side view of the input device with an illumination function according to the embodiment.

FIG. 3 is a cross-sectional view of the assembled input device with an illumination function according to the embodiment.

FIG. 4 is a cross-sectional view of a main part of a light guide plate according to an embodiment.

FIG. 5 is an exploded side view of an input device with an illumination function according to a conventional example.

Explanation of symbols

1 Wiring board

2 Light emitting diode

4 Light guide plate

5 Conduction post (fixed contact)

6 Metal dome

7 Actuator

8 Cover sheet

9 Step

Claims

The scope of the claims

[1] A wiring board on which a required wiring pattern is formed, a light emitting diode mounted on the wiring board, a light guide plate that guides light emitted from the light emitting diode in a plane direction, and a light guide plate A fixed contact of a pushbutton switch that is electrically connected to the wiring pattern and a movable contact of the pushbutton switch that switches between the plurality of fixed contacts to a conductive state or a nonconductive state. A certain metal dome and a cover sheet provided with an actuator for pressing the metal dome,

An input device with an illumination function, wherein a bottom surface for guiding light emitted from the light emitting diode in a surface direction is formed in a setting portion of the metal dome in the light guide plate.

[2] A conductive post penetrating the back surface force of the light guide plate as the fixed contact is used, and the wiring pattern and the fixed contact are electrically connected by bringing the wiring board and the light guide plate into close contact with each other. The input device with an illumination function according to claim 1.

[3] The input device with an illumination function according to [1] or [2], wherein the wiring board is formed of a light-shielding white material.

[4] The input device with an illumination function according to [1], wherein the cover sheet is formed of a translucent white material.

5. The input device with an illumination function according to claim 1, wherein the cover sheet is made of a transparent material.

6. The input device with an illumination function according to claim 1, wherein the cover sheet is formed of a transparent material, and a light diffusion process is performed on a surface thereof.

7. The input device with an illuminating function according to claim 1, wherein the actuator is made of a light-shielding white material.

8. The input device with an illumination function according to claim 1, wherein the actuator is formed of a transparent material.