JPH0447929B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a thin keyboard switch made of plastic film and made transparent including the contact pattern. This invention relates to an improvement in a keyboard switch that can prevent a decrease in visibility due to interference fringes generated on the keyboard switch when the switch is operated while looking through the display from above the keyboard switch.

``Prior Art'' This type of sheet-like or membrane-type keyboard switch, which is mainly made of plastic film material, is widely used as a switch input means in various fields such as electrical and electronic equipment, and its basic structure is as follows.
Two plastic films are prepared to serve as the base material and the switch sheet, and a plurality of required contact patterns are provided facing each other on these films to form multiple sets of switch operation gaps. In some embodiments, a structure is known that includes a dome-shaped switch seat or the like that gives the operator a switch operation sensation such as a clicking sensation when operating the switch. Such a keyboard switch can be constructed in a thin and flat shape,
In addition to being easy to install in a variety of layouts for equipment, it is also possible to obtain optimal design effects for the entire product, such as equipment, so the field of use is extremely wide.

Furthermore, this type of keyboard switch can be entirely transparent if the contact pattern is formed using a transparent conductive material such as indium oxide, and this type of keyboard switch can be used in various types. A configuration has also been proposed in which the device is placed on a display and required switch operations are processed while viewing the display appearing on the display from above.

``Problems to be solved by consideration'' In the transparent type keyboard switch as described above, as conceptually shown in Fig. 2, a base material is provided with a fixed contact pattern 3 such as a comb-shaped electrode made of a transparent conductive material. A see-through type keyboard switch body is formed by positioning and disposing a switch sheet 2 on which a transparent movable contact pattern 4 is formed to form a switch mechanism, using an adhesive or the like in view of transmittance. The optional decorative board 8 is placed on the switch sheet 2.
It is originally designed to allow for the provision of

When performing a switch operation while looking through the display on the display 5 from above the keyboard switch, the contact surface 6 between the keyboard switch and the display 5 or the contact surface 9 between the switch sheet 2 and the decorative board 8 should be aligned with each other. Because they are not in a close contact state and a small gap is partially formed, the difference in reflectance between the close contact surface and the small gap surface causes a so-called moiré phenomenon in which interference fringes appear when viewed from above. Otherwise, the visibility of the display 5 may be deteriorated, such as when only the closely-contacted portion appears wet, which may impede switch operation.

"Means for Solving the Problems" The present invention provides a keyboard switch that can prevent visibility deterioration due to interference fringes or moiré that often occur in transparent keyboard switches such as those described above. Therefore, in the present invention,
A transparent film or matte is formed on the contact surface between the transparent keyboard switch body and the display and/or the decorative board.

"Operation" According to the interference fringe prevention structure consisting of the above means, it is possible to easily obtain a uniform contact state between the keypad switch main body and the decorative panel or the display, or both, so this kind of see-through type keyboard It becomes possible to maintain stable visibility of the switch.

"Embodiment" FIG. 1 shows a conceptual cross-sectional configuration diagram of a keyboard switch according to an embodiment of the present invention.
The same reference numerals as those in the figures refer to the same components,
In this embodiment, a transparent plastic film 7 is uniformly laminated on the switch sheet 2 to prevent interference fringes, so-called moiré, that may occur on the contact surface 9 with the decorative board shown in FIG. This is what I did. In addition, as an interference fringe prevention structure, as shown in FIG.
Either matte surfaces 1A and 2A are formed on the upper surfaces to sufficiently prevent the occurrence of moire on both contact surfaces 6 and 9, or as a simple means, separate transparent surfaces 1A and 2A are formed on the upper surfaces, respectively. It is also possible to prepare a film 10, form a matte finish 10A in the same way as described above, such as by embossing on both sides, and arrange this between the base material 1 and the display 5. As a modification of this case, it is also possible to form a matte film 10A only on the upper surface of the film 10, and apply matte coating to the glass surface of the display 5 as shown in FIG. 2. As another embodiment of the interference fringe prevention structure, as shown in FIG. 5, in a structure using a transparent decorative board 8, it is also preferable to form a matte layer 8A on both sides of the decorative board 8. be.

The above-mentioned various interference fringe prevention structures can be achieved by comprehensively considering the structure of the keyboard switch, the model or function of the display 5, etc., and adopting a single structure or an appropriate combination structure. It is possible to construct an optimal interference fringe prevention structure.

In addition, the keyboard switch in the drawing shows a switch sheet that maintains an operating gap by molding as an example of use, but this can be constructed in a flat shape similar to the base material, and can also be constructed using the required spacers. It is clear that the interference fringe prevention structure can be applied in the same way.

``Effects of the Invention'' As mentioned above, the keyboard switch of the present invention is configured so that a see-through type keyboard switch used by being placed on various displays is provided with an interference fringe prevention structure. It is possible to provide a keyboard switch with excellent operability while ensuring good display visibility. In addition, such an interference fringe prevention structure has the feature that it can be easily attached to various types of keyboard switches of this type, and despite its simple structure, it can be applied to see-through type keyboard switches to great effect. be.

[Brief explanation of the drawing]

FIG. 1 is a conceptual cross-sectional diagram of main parts of a see-through type keyboard switch which has an interference fringe prevention structure according to an embodiment of the invention, and FIG. 2 shows similar main parts of a see-through type keyboard switch with a conventional structure. FIGS. 3, 4, and 5 are similar cross-sectional views of keyboard switches according to other embodiments. The names of each symbol shown in the attached drawings are as follows:
It is as follows. 1: Base material, 1A: Matte, 2: Switch sheet, 2A: Matte, 3: Fixed contact pattern,
4: Movable contact pattern, 5: Display, 6:
Contact surface, 7: Transparent film, 8: Decorative board, 8A:
Matte, 9: Contact surface, 9A: Matte.

Claims (1)

[Claims] 1. A switch sheet having another contact pattern formed thereon so as to face the contact pattern is disposed above a base material having a required number of contact patterns,
A switch operation gap is formed between both of these contact patterns, and each component including both of the contact patterns is arranged transparently on a display, and the switch is operated while looking through the display from above. A keyboard switch according to the invention, characterized in that an interference fringe prevention structure is provided in association with the base material or the switch sheet. 2. The keyboard switch according to claim 1, wherein the interference fringe prevention structure comprises a transparent film adhered to the upper surface of the switch sheet. 3. The keyboard switch according to claim 1, wherein the interference fringe prevention structure comprises matte means provided on the outer surface of one or both of the base material and the switch sheet. 4. The keyboard switch according to claim 1, wherein the interference fringe prevention structure comprises a transparent film matting means provided on the lower surface of the base material. 5. The keyboard switch according to claim 1, wherein the interference fringe prevention structure comprises a matting means of a decorative plate provided on the upper surface of the switch sheet. 6. The keyboard switch according to claim 1, wherein the interference fringe prevention structure comprises matting means provided on the glass surface of the display.