JPH02148633A - Back light membrane switch - Google Patents

Abstract

PURPOSE:To improve the lighting degree of key display and ensure a sufficient brightness of the whole by condensing the light of a light source by a lens, introducing said light to the hole of a crick plate through a transparent electrode sheet and a hole provided on an opaque electrode contact point, and diffusing the light to the whole key in the mounting shaft part of the key. CONSTITUTION:A switch has an upper electrode sheet 32 and lower electrode sheet 3 formed of transparent insulating resin sheets in which electrode contact points 35 made of opaque conductive materials having light-permeating holes 35a formed thereon are provided in such a manner as to be capable of contacting and separating to each other are provided. It comprises a doom form crick plate 36 having a hole 36a for permeating light formed thereon which plate is situated above the electrode contact point 35 and provided on the upper surface of the upper electrode sheet 32, a transparent key 37 inserted into this hole 36a, and a light source 43 situated below the electrode contact point 35 and provided through a introducing plate 39 subjected to lens processing. The light of the light source 43 is condensed by a lens 41, introduced to the hole part 36a of the crick plate 36 through the hole 35a of the electrode contact point and the upper and lower electrode sheets 32, 33, and diffused to the whole key 37. Hence, the whole key display part of the transparent key 37 can be lighted at an uniform and sufficient illumination.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a backlight membrane switch used in keyboards and the like to open and close electric circuits.

2. Description of the Related Art Conventionally, backlight membrane switches shown in FIGS. 2 and 3 are known as examples of membrane switches used in keyboards and the like to open and close electric circuits. In this device, an upper electrode sheet 1 and a lower electrode sheet 2 made of flexible insulating resin (for example, polyester resin) are laminated with a spacer 3 interposed therebetween, and electrode contacts 4.4 are formed on mutually opposing surfaces of each sheet 1.2. An electrode sheet 5 provided with
A click plate 6 is provided on the top surface above the electrode contact 4, and a spacer 7 having a thickness approximately equal to the height of the lithic plate 6 is placed around the click plate 6. A flexible surface resin sheet 8 is adhered to the electrode contact point 4.
．． A light source LED 9 is installed on the side of 4, and this light source LED
9 enables illumination, and displays the arrangement of keys (switch operation buttons) 10 by printing on the part of the surface resin sheet 8 facing the click board 6, and by pressing this printed display part, the keys (switch operation buttons) 10 can be illuminated through the click board 6. Touch the electrode contacts 4, 4 to turn on the switch consisting of these electrode contacts,
At this time, the structure is such that a click feeling can be obtained due to the elasticity of the click plate 6.

Further, as an example of another membrane switch, a backlight membrane switch not shown in FIG. 4 is known. This one consists of a surface resin sheet 11° light guide plate + 2. Spacer 13. Upper electrode sheet 14° lower electrode sheet 15. L.E.
D electrode resin sheet 16 Click board 17. Electrode contact 1
8. It consists of 19 LEDs and has a structure that guides the light from 9 LEDs to the surface through the light guide plate 12. Because the electrode position on the plane and the mounting position of the LED are different, the membrane switch thickness is maintained almost the same as when there is no LED. It has the characteristics of being able to

Furthermore, as an example of another membrane switch, the fifth
A backlight membrane switch shown in the figure is known. This is a transparent surface resin sheet 21. Spacer 23. Transparent upper electrode notebook 24. Transparent lower electrode sheet 25. LED electrode electrode resin sheet 26 Transparent rick plate 27. Opaque electrode contacts 28. It consists of an LED 29, and by installing the LED 29 below the electrode contact 28, the structure is such that the upper part is illuminated.

``Problems to be Solved by the Invention'' However, in the conventional backlight membrane switch not shown in FIGS. It is difficult to uniformly illuminate the entire display area, which is inconvenient when used in a dark place, and there are problems in that the brightness of the entire key display area is insufficient.

In addition, the conventional backlight membrane switch shown in FIG. 4 requires a separate light guide plate 12, which is expensive, and the brightness may be lost depending on the installation location of the LED I 9, or it may be difficult to guide the light properly. There is a problem that it is difficult to process and laminate the light guide plate 12.
Since the click plate 17 is pressed via the contact point 2, the click feeling changes depending on the suppressed position and the operation of the electrode contact 18 becomes incomplete, which may result in poor contact of the electrode contact 18.

In addition, in the conventional backlight membrane switch shown in FIG.
The light is obstructed by the click board 27 and is attenuated, resulting in a decrease in illuminance and a drawback that brightness cannot be ensured. Therefore, it is possible to make holes in the click plate 27 in order to increase the amount of light passing through, but the problem is that the amount of light decreases, it is not possible to obtain sufficient illuminance, and it is difficult to obtain a sufficient click feeling. there were.

SUMMARY OF THE INVENTION An object of the present invention is to provide a backlight membrane switch that can solve the above-mentioned problems of the conventional switch and illuminate the entire key display section with uniform and sufficient illuminance.

"Means for Solving the Problem" The first invention has the following configuration to achieve the above object. That is, the electrode contacts are stacked so as to be separated and face each other with a spacer interposed therebetween, and electrode contacts each made of an opaque conductive material and having a hole through which light is formed are provided on opposing surfaces within the space so as to be able to move toward and away from each other. an upper electrode sheet and a lower electrode sheet made of a transparent insulating resin sheet, and a hole is formed on the upper surface of the upper electrode sheet to be located above the electrode contact point and for transmitting light, and is further embossed. a dome-shaped click plate, a transparent key fitted into the hole of the click plate, and a light guide plate located below the electrode contact point and provided below the lower electrode sheet through a lens-processed light guide plate. The structure consists of a light source.

A second aspect of the present invention is that in the first aspect, a dome-shaped click plate and an enclosure surrounding the keys are provided on the upper electrode sheet.

"Function" The first invention focuses light from a light source using a lens, guides the light through a transparent lower electrode sheet, a transparent upper electrode sheet with holes in the electrode contact, and a hole in the click plate. To illuminate the entire key display part of a transparent key fitted into a hole in a plate with uniform and sufficient illuminance. In addition, the elasticity of the click plate provides a click sensation when operating keys.

The second invention focuses light from a light source using a lens, and guides this light to the hole portion of the click plate through a transparent lower electrode sheet, a through hole provided in an opaque electrode contact, and a transparent upper electrode sheet. , the entire key display part of the key fitted in the hole of the click board is illuminated with uniform and sufficient illuminance.

Additionally, the enclosure surrounding the click plate guides the movement of the keys in a stable state.

In addition, the elasticity of the click plate provides a click sensation when operating keys.

"Example" An embodiment of the present invention will be described below with reference to FIG.

Figure 1 is a longitudinal cross-sectional view of a backlight membrane switch, and 31 in the figure is 7t! This electrode sheet 31 is made by laminating an upper electrode sheet 32 made of a flexible and transparent insulating resin (for example, polyester resin) and a lower electrode sheet 1-33 made of a transparent insulating resin with a spacer 34 in between. , an upper electrode sheet 32 and a lower electrode sheet 33 are provided with electrode contacts 35 and 35 which are opaque and have a hole 35a formed in the center, respectively, facing each other. The electrode contacts 35.35 are made of an opaque conductive material (e.g. carbon or silver paste) and are made of an upper electrode sheet 32.35. A spacer 3 is located between the lower electrode sheets 33.
It is provided in a space 34a formed in 4.

An opaque rick plate 36 made of a metal plate embossed into a dome shape is provided on the upper surface of the II pole receipt 31 and positioned above the electrode contacts 35. A hole 36a is formed in the center of the click plate 36.
The mounting shaft 37a of a transparent key 37, which is provided with a mounting shaft (transparent) 37a at the bottom thereof, is fitted into the key 6a.

An enclosure 38 having a thickness slightly thicker than the height of the click plate 36 is installed around the click plate 36.
6 and the key 37, and is bonded to the upper electrode sheet 32. That is, click board 3
6 and the key 37 are located in a space 38a formed in the enclosure 38, and the key 37 is guided by the inner wall of the space 38& to stably move up and down.

A light guide plate 39 made of transparent injection molded polycarbonate is attached to the lower surface of the lower electrode sheet 33 . This light guide plate 39 is provided with a recess 40 . A portion corresponding to the bottom of this recess 40 is processed into a lens, and a lens 41 is provided below the electrode contacts 35 and 35 and at a position in contact with the lower electrode sheet 33.

A light source resin sheet 42 made of glass or epoxy is adhered to the lower surface of the light guide plate 39 .

On the light source resin sheet 42, a light source ED43 is fixedly provided below the electrode contact 3535 and the lens 41.

A key display (switch operation button display) is printed on the upper end surface of the key 37 in FIG. 1.

Then, by pressing the printed display part of this key 37, the electrode contacts 35 and 35 are brought into contact via the click plate 36, and these 1! A switch consisting of contact points 35.degree. 35 is turned on, and at this time a click feeling is obtained due to the elasticity of the click plate 36.

By turning on the light source LED 43, the light from the light source LED 43 is focused by the lens 41, and the light guide plate 3
9. Lower electrode sheet 33. Hole 35 of electrode contact 35.35
a, 35a, reaches the mounting shaft 37a of the click board 36 through the upper electrode sheet 32, and since the key 37 is transparent, the illuminance is diffused within the key 37, and the entire key display area is illuminated with uniform and sufficient illumination. Illuminate and clearly indicate keys.

Since an enclosure 38 is provided around the key 37, this enclosure 38 allows the key 3
7 is guided to move up and down stably in FIG.

Furthermore, according to this embodiment, the cost of the backlight membrane switch can be reduced because inexpensive opaque electrode contacts 35,35 can be used instead of expensive transparent electrode contacts.

"Effects of the Invention" According to the first invention, the stacks are stacked facing each other with a space between them, and holes made of an opaque conductive material and transmitting light are formed on opposing surfaces within the space. an upper electrode sheet and a lower electrode sheet consisting of a transparent insulating resin sheet (transparent insulating resin sheet) in which electrode contacts are provided so as to be able to freely approach and separate from each other; a dome-shaped click plate formed with an embossed hole for transmitting the light; a transparent key fitted into the hole of the click plate; and a light guide plate located below the electrode contact and processed with a lens. Since the structure consists of a light source provided below the former lower electrode sheet through the electrode, instead of the electrode contact made of a transparent conductive material, it is made of an opaque conductive material (e.g. carbon or silver paste) and transmits light. By providing an electrode contact with a through hole, the light from the light source is focused by the lens, and the light is passed through the transparent lower electrode sheet, the hole provided in the opaque electrode contact, and the transparent upper electrode sheet. By guiding the light into the hole in the click plate, concentrating it on the key mounting shaft, and diffusing this light to the entire key, the illumination level of the key display is improved and the overall brightness of the key display area is ensured. This allows the entire key display area to be illuminated with uniform and sufficient illuminance, and by using inexpensive opaque electrode contacts instead of expensive transparent electrode contacts, the cost of backlight membrane switches can be reduced. It can be made inexpensive, and the elasticity of the click plate can provide a click feeling when operating keys.

Further, according to the second invention, in addition to the effects of the first invention, the enclosure provided on the upper electrode sheet can guide the movement of the key in a stable state, and further improve durability. can.

[Brief explanation of the drawing]

FIG. 1 is a partially omitted vertical sectional view showing an embodiment of the present invention, FIGS. 2 and 3 are examples of a conventional keyboard switch, and FIG. 2 is a partially omitted longitudinal sectional view, and FIG. Fig. 3 is a plan view of the main parts, Fig. 4 is a partially omitted longitudinal cross-sectional view showing another example of a conventional keyboard switch, and Fig. 5 is a partially omitted longitudinal cross-section showing yet another example of the conventional keyboard switch. It is a diagram. 31... Electrode sheet, 32... Upper electrode sheet, 33... Lower electrode sheet, 34...
...Spacer, 34a... Space, 35...
・・Electrode contact, 35a, 36a...hole, 3G・
...Click board, 37...Key 38...
... Enclosure, 39 ... Light guide plate, 4
3...Light source LED.

Claims (1)

[Scope of Claims] 1. A spacer (34) having a space (34a) is interposed between the layers to face each other, and holes (35a) made of an opaque conductive material and allowing light to pass through are formed on opposing surfaces within the space.
) are formed on an upper electrode sheet (32) and a lower electrode sheet (33) made of a transparent insulating resin sheet, on which electrode contacts (35) are provided so as to be able to come into contact with and separate from them, and the electrodes are formed on the upper surface of the upper electrode sheet. a dome-shaped click plate (36) located above the contact point, formed with a hole (36a) for transmitting light, and further embossed;
a transparent key (37) fitted into the hole of the click plate;
A backlight membrane switch comprising: a light source (43) located below the electrode contact point and provided below the lower electrode sheet via a lens-processed light guide plate (39). 2. The backlight membrane switch according to claim 1, further comprising an enclosure (38) surrounding the dome-shaped click plate and the key on the upper electrode sheet.