JPH074740Y2 - Illuminated keyboard switch - Google Patents

Description

[Detailed Description of the Invention] "Industrial field of application" The present invention provides a light-transmitting transparent plate on the upper surface of a membrane-type keyboard switch for diffusely reflecting light from a light source emitted from an end into flat light. The present invention relates to an illuminated keyboard switch, and in particular, it is mounted on a light guide transmissive plate by forming transmissive thin film layers on both sides of the light guide translucent plate to enhance diffuse reflection efficiency. Relates to an illuminated keyboard switch which is easy to manufacture and has high operability and durability, which is configured to illuminate the operation display sheet efficiently and uniformly.

"Prior art" Edge input irradiation light from a light source such as a lamp or light emitting diode installed at the end is made incident on a light guide translucent plate made of an acrylic resin plate, etc., and diffusely reflected in the plane direction of the translucent plate. A structure for illuminating a part or the whole of the operation display panel on the upper surface of the keyboard switch of this type is known.

In such an operation panel surface illumination structure, for example
The invention according to Japanese Patent Publication No. -037123 discloses an acrylic resin plate in which a large number of lattice-shaped fine grooves are formed on the installation surface for a reflecting plate such as a white synthetic resin sheet, and a fixed contact pattern made of a transparent metal film is formed on the upper surface. And a structure in which a light-guiding plate such as the above is provided, and other constituent members of the film-type keyboard switch are mounted on the light-guiding plate so that only the operation display portion of the operation panel is illuminated. In the device disclosed in Japanese Utility Model Publication No. 61-6223, a light guide plate having a translucent push button for pressing a membrane keyboard switch through a click operation plate is mounted on the upper portion of the keyboard switch body, and the light guide plate is provided. Disclosed is a structure for internally illuminating only the top of the translucent push button which is exposed by a light reflecting function of a hairline-shaped undulation formed on the bottom surface.

"Problems to be solved by the invention" In the above-mentioned conventional example, the membrane type keyboard switch is transparent, and the backside illumination method is adopted.
In the case of the invention of Japanese Patent No. 3, it is necessary to set the irradiation light quantity at the end of the light guide plate to a considerably high level. Therefore, the number of installed light sources such as light emitting diodes to be attached to the end of the light guide plate and its wiring means In addition to the increase, it is difficult to avoid complication at the time of mounting on equipment etc.In addition, in order to improve the operability of this type of membrane keyboard switch, it is also possible to provide a mechanism to give a click feeling to each key. Have difficulty.

In the invention of Japanese Utility Model Publication No. Sho 61-6223, in which the light guide plate is arranged on the upper surface of the membrane type keyboard switch body, unlike the above structure,
Although it is easy to provide a click function, the click action plate that also uses the light reflection function is installed on the top surface of the membrane keyboard switch body as a means for that. It may not match the OFF operation, and the exposed structure of the switch push button top has a difficulty in durability due to intrusion of water and other dust. Therefore, if dust or the like adheres to the portion, the light receiving property may be impaired.

Further, in the conventional structure as described above, the bottom surface of the light guide plate is provided with irregular reflection starting portions such as lattice-shaped narrow grooves and hairline-like undulations. The loss of light is high, and as a result, the number of required light sources such as lamps increases, and therefore the amount of heat generated at the end of the light source installation also increases due to the increase in the amount of input irradiation light. In addition to the need to use materials, it may be necessary to provide a heat dissipation mechanism. Further, since the loss of the input irradiation light is high, when it is necessary to configure a large illuminated surface, it is not possible to obtain uniform planar illumination only with the input irradiation light only on the end side surface of the light guide plate, There are great difficulties in its design, such as uneven illumination.

[Means for Solving the Problems] The present invention is a light guide translucent plate provided with a transmissive layer on the upper surface of a main body of a membrane keyboard switch for efficiently diffusely reflecting irradiation light from an end into uniform plane irradiation light. The keyboard switch operation area of the light guide transmissive plate is equipped with a transparent switch push button at the relevant portion, and the operation is performed by applying the required design on the switch push button and the light guide translucent plate. Illuminated keyboard equipped with a display sheet that efficiently diffuses the input light emitted from the edges while ensuring good switch operability and having a high-luminance operation panel surface illumination function with a simple and low-cost mechanism. It provides a switch.

In order to achieve such an object, in the illuminated keyboard switch according to the present invention, a fixed number of fixed contact patterns are formed on an insulating base sheet, and movable contact patterns are formed at positions corresponding to the fixed contact patterns. A film-type keyboard switch in which a flexible insulating switch sheet and a flexible insulating switch sheet are arranged to face each other with a required switch operation gap, and a light guide transparent plate disposed on the switch sheet is provided. A transparent thin film layer having a refractive index smaller than that of the light-transmitting plate is provided on both surfaces of the light-transmitting plate, and the light-transmitting light-transmitting plate is attached to a through-hole formed at a position corresponding to the switch operation gap. A transparent switch push button, and an operation display sheet provided on the switch push button and the light guide translucent plate upper surface,
A part of the transmissive thin film layer is configured to include a display transmissive layer having a refractive index larger than that of the translucent plate in a portion corresponding to the display portion of the operation display sheet. As a result, the display portion of the operation display sheet can be illuminated with high brightness through the display transmission layer.

[Examples] Hereinafter, the present invention will be described in more detail with reference to the illustrated examples. Referring to the drawings, reference numerals 1 to 3 are respective members constituting the main body of the film type keyboard switch, and for the insulating base sheet 1 made of an appropriate plastic film or the like, a required fixed contact pattern 1A has its wiring pattern. The insulating base sheet 1 is optionally formed by etching means for copper foil and the like, and the insulating base sheet 1 is provided with a flexible insulating switch sheet through an insulating spacer 3 having a through hole for providing a switch operation gap 3A in a region where the contact pattern 1A is formed. Two
A membrane type keyboard switch main body is formed by forming a required movable contact pattern 2A on a lower surface portion of the flexible insulating switch sheet 2 opposed to the fixed contact pattern 1A.

On the flexible insulating switch sheet 2 of the membrane type keyboard switch body, a transparent conductive plate such as a transparent glass plate or an acrylic resin plate for irradiating light emitted from a light source from the end in a plane direction is used. The translucent plate 5 for light is installed,
A transparent switch push button 7 is movably mounted in a vertical direction in a through hole 5A formed at a position corresponding to the switch operation gap 3A of the transparent plate 5, and the switch push button 7 is provided at a central portion of a lower surface thereof. The columnar working protrusion 7A is provided, and the working protrusion 7A functions to apply an operation pressing force to the flexible insulating switch sheet 2.

Here, a transparent thin film layer 6 having a refractive index different from that of the light guide plate 5 is formed on both surfaces of the light guide translucent plate 5, and a switch pushbutton is formed on a part of the upper surface side thin film layer 6. A transparent layer 6A for display, which is composed of characters, symbols or figures for specifying each switch in association with 7, is provided. Then, in order to illuminate the edge input light with high brightness to the display section of the operation display sheet described later through the display transmission layer 6A, the light guide transmissive plate 5 has a refractive index of N ₁ , If it a refractive index of N ₂ or the display permeable layer 6A, sex film layer 6 and N _3, it is preferable to determine the of refractive index relationship _{N 3> N 1> N 2} .

Reference numeral 8 denotes a transmissive operation display sheet provided on the upper surfaces of the light guide translucent plate 5 and the switch push button 7 and having a desired design indication. The display sheet 8 corresponds to the display transmissive layer 6A. It is also possible to form the required operation display portion 8A at the above-mentioned position by an appropriate means such as printing or the like, while providing the embossing portion 8B at the portion corresponding to the position of the switch push button 7. Reference numeral 9 denotes a light source such as a lamp as an end input irradiation light arranged adjacent to the end of the light guide translucent plate 5.

The above-mentioned membrane type keyboard switch body does not need to be configured with transparent components such as the fixed and movable contact patterns 1A and 2A, and can be constructed as cheap as possible according to the conventional structure.

Since the light source 9 as the end input irradiation light is arranged adjacent to the end of the translucent plate 5, the translucent plate 5 on which the switch push button 7 is mounted and the operation display sheet 8 are attached to the membrane keyboard switch body by screwing. It can be easily processed by using a holder, a clamp, a holder for the light source 9 or the like.

According to the above structure, the edge irradiation light from the light source 9 introduced from the edge of the light-transmitting transparent plate 5 repeats the total reflection in the thin film layers 6 formed on both surfaces of the transparent plate 5. While translucent plate 5
While diffused uniformly in the interior of the display panel, suitable diffused reflection is generated at each part of the transparent switch push button 7 and its action projection 7A, and the diffused reflected light uniformly illuminates the entire surface of the operation display sheet 8 from the inside. At the same time, the operation display unit 8A receives internal illumination with high brightness via the display transmission layer 6A. Therefore, it becomes easy to selectively identify each operation display portion 8A on the operation display sheet 8 surface, and the embossed portion thus specified can be identified.
It is possible to reliably achieve the on / off operation of the membrane keyboard switch having the structure shown in the figure via the switch push button 7 in response to the application / release of the pressing force to the 8B.

In such a switch operation, the action protrusion 7A of the transparent switch push button 7 is not limited to the central portion of the embossed portion 8B corresponding to the upper surface of the push button 7, but a pressing force applied to the end portion thereof. Even when this is done, since it acts on the optimum position of the switch, it is possible to satisfactorily reduce the input operation error, which is a problem in the case of this type of membrane keyboard switch, while
In the presence of the push button main body, in combination with the suitable condensing function of the diffused reflection light, it effectively contributes to the illumination effect on the embossed portion 8B, and accordingly, the high brightness illumination of the operation display portion and the operation panel surface illumination are provided. It is possible to improve the selection operability by the function and ensure the switch input operation processing.

"Effect of the device" The illuminated keyboard switch of the present invention is provided with a light guide translucent plate having a translucent thin film layer formed on the upper surface of the film type keyboard switch to efficiently assist total internal reflection. Since the translucent plate for light guide is configured to have a transmissive switch push button, it is transmitted to the operation display sheet while appropriately diffusely reflecting the end input irradiation light from the light source arranged adjacent to the end of the translucent plate. Simplifies the operation panel surface illumination structure that minimizes light attenuation and uses low-power input illumination light, thus reducing the number of installed light sources and achieving uniform illumination with extremely high illumination efficiency even for products with large areas. Can be manufactured.

The transparent thin film layers formed on both sides of the light guide translucent plate have a refractive index smaller than that of the light transmissive plate for light guide, and a part of the transparent thin film layer has a refractive index of the transparent plate. Since the display transmissive layer having a refractive index larger than that of the index is formed, the display part of the operation display sheet corresponding to the display transmissive layer can be illuminated with higher brightness than other parts, so that the switch distinguishability can be improved. Can be further increased.

Since the number of input light sources installed at the end of the light guide transmissive plate can be reduced, heat generation by these light sources can be suppressed, and therefore,
By using an inexpensive material for the light guide translucent plate, a large area product can be constructed at low cost.

Since the operation panel surface illumination structure including the light guide translucent plate and the transmissive switch push button is mounted on the upper surface of the membrane keyboard switch body, the membrane keyboard switch body is not limited by the illumination mechanism. It can be achieved as cheaply as possible with the conventional structure, and therefore the specifications can be accommodated with high flexibility.

Since the light guide translucent plate also functions as a protection function for the membrane keyboard switch body in cooperation with the operation display sheet on the surface, it is possible to suitably prevent damage or damage to the membrane keyboard switch body due to unexpected external pressure or the like. Since the operation display sheet has a surface-sealed structure, intrusion of fluid such as water and intrusion of other dust can be prevented and stable operation reliability can be ensured.

By mounting the operation panel surface illuminating structure and the transparent switch push button, the switch input operation can be reliably processed by significantly improving both the selective identification of the operation display unit and the switch operability.

Combined with the structure that the end light source for input irradiation is adjacent to the end of the light guide transmissive plate and can be collectively installed, it is easy to manufacture and assemble, and the mounting process for equipment is also easy. It

Therefore, a highly functional and practical illuminated keyboard switch having excellent reliability and durability can be provided at low cost.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an illuminated keyboard switch having an operation panel surface illumination structure in which a film-type keyboard switch body is provided with a light guide translucent plate having high reflection efficiency according to an embodiment of the present invention. It is a conceptual principal part cross-section block diagram. 1: Insulating base sheet 1A: Fixed contact pattern 2: Flexible switch sheet 2A: Moving contact pattern 3: Insulating spacer 3A: Switch operation gap 5: Light guide translucent plate 5A: Push button mounting translucent hole 6: Transparency Thin film layer 6A: Transparent layer for display 7: Switch push button 7A: Working protrusion 8: Operation display sheet 8A: Operation display section 8B: Embossed section 9: Edge input irradiation light source

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-60-175326 (JP, A) JP-A-62-283510 (JP, A) JP-A-61-131314 (JP, A) Actual development Sho-61- 6223 (JP, U) Actually opened 59-188634 (JP, U) Actually opened 61-126340 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. An insulating base sheet having a required number of fixed contact patterns formed therein and a flexible insulating switch sheet having movable contact patterns formed at positions corresponding to the respective fixed contact patterns are provided with a required switch operation gap. In the membrane type keyboard switch arranged opposite to each other, a light guide translucent plate disposed on the switch sheet is provided, and both sides of the light guide translucent plate have a refractive index of the translucent plate. A light-transmitting thin film layer having a small refractive index is provided, and a light-transmitting light-transmitting plate is provided with a light-transmitting switch push button mounted in a through hole formed at a corresponding position of the switch operation gap. An operation display sheet disposed on the upper surface of the light guide translucent plate, wherein a part of the transmissive thin film layer has a refractive index higher than that of the translucent plate at a portion corresponding to the display portion of the operation display sheet. Transparent layer for display having refractive index Illuminated keyboard switch, characterized by being configured to include.