JPH0335766B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing key tops for various devices such as keyboards for word processors and microcomputers, calculators, etc., in which an identification display pattern on the key top is formed from a radiation-cured resin, and the pattern is made colorless. Alternatively, it may be covered with a colored transparent cover body to form a key top.

The key tops installed on the keyboards of word processors, microcomputers, calculators, etc. are operated by pressing them with your fingertips, and patterns such as letters and figures are formed on the top surface of the key tops for identification. . Conventionally, as shown in FIGS. 6a and 6b, for example, when molding this type of key top, a fitting groove 6b is integrally formed in the upper part of the key top body 6a, and a desired identification display pattern (for example, As shown in the figure, the letter "A") is formed by printing means such as silk screen printing or hot stamping, and after drying and curing the pattern, a transparent cover sheet 6c is fitted into the fitting groove 6b. It had been. However, such a forming method is inferior in workability because it takes a considerable amount of time for the paint to dry and harden, and if there is even a slight deviation in shape or dimension, it becomes impossible to fit the cover sheet 6c into the fitting groove 6b. In other cases, the cover sheet 6c is not firmly fixed in the fitting groove 6b, and the cover sheet 6c may shift or wobble when the key top is pressed, and furthermore, the cover sheet 6c may protrude from the periphery of the fitting groove 6b. Since it is only locked to the protrusion 6d,
There was a risk that it would fall off from the fitting groove 6b. Therefore, when forming this type of key top by the above method,
It is necessary to strictly mold and control the molding die for the key top body 6a, which has the drawback of increasing costs.

In addition, conventionally used printing paints for forming patterns cure by evaporation of the internal solvent, and upon curing, drying shrinkage occurs and countless fine cracks occur on the surface. Moisture in the air and cleaning liquids such as alcohol for wiping can easily penetrate into such cracks due to their capillary action, and once moisture has entered the crack, it is difficult to evaporate. As a result, this water content significantly accelerated the peeling off of the paint and the deterioration and discoloration of the paint, causing the pattern to gradually become less clear and difficult to read. In addition, the key top easily gets dirty due to the adhesion of hand grime and dust, so it is necessary to periodically wipe it with a cleaning solution such as alcohol, but since this type of paint has poor chemical resistance, the fitting groove 6b The problem was that the cleaning solution that entered the inside of the paper caused it to peel off, deteriorate, and fade, resulting in poor legibility.

Therefore, the present invention has been made for the purpose of providing a keytop which eliminates the drawbacks of the conventional ones, and is comprised of a keytop main body and a colorless or colored transparent radiolucent cover covering at least the upper surface of the main body. At the same time, radiation curing resin is applied to at least one of the upper surface of the key top body or the corresponding surface of the cover body in a predetermined identification shape, and then the two are brought into close contact with each other, and then the radiation is applied to the cover body. The key top is formed by irradiating the radiation-cured resin through the body and curing it, which makes the key top easy to use and does not reduce the distinguishability of the pattern even if used for a long time. , which can be formed with good workability.

Hereinafter, embodiments of the present invention will be described in order of steps with reference to the drawings.

In Fig. 1a, 1 is a truncated quadrangular pyramid-shaped key top body, and 2
A rectangular groove 2 is formed at a depth of about 5 mm. On the upper surface of the groove 2, the letter "A" as a desired pattern serving as an identification indicator is formed by applying a radiation curable resin such as an ultraviolet ray curable resin or an electron beam curable resin in a slightly thick manner. A radiation-transparent cover body 3 made of a colorless or colored transparent transparent synthetic resin plate, glass plate, etc. is attached from above, and the upper surface of the pattern "A" is brought into close contact with the lower surface of the cover body 3. Next, the radiation curing resin is irradiated with radiation such as ultraviolet rays or electron beams from above through the cover body 3 by the radiation irradiator 4 to harden the pattern "A" which will become the identification display (see FIG. 1b). Radiation-cured resin has the property of adhering extremely strongly to various synthetic resins such as ABS resin, which are commonly used as materials for this type of key top and cover body. The cover body 3 and the key top body 1 are firmly fixed to the upper and lower surfaces of the pattern "A", and a strong key top 5 is completed. Furthermore, radiation-curable resins harden by causing chemical reactions such as polymerization reactions, condensation reactions, and crosslinking reactions when irradiated with radiation, and the curing process is extremely fast. It cures with good workability and has very good aesthetics after curing.

In addition, since the top surface of the pattern "A" is in close contact with the cover body 3 and is completely protected by the cover body 3, the top surface of the pattern "A" will not come into contact with the air and its clarity will not deteriorate. Further, even if the key top main body 1 or the cover body 3 have a deviation in size or shape, the cover body 3 will not shift or shake when the key top 5 is pressed, and therefore, the present key top 5 is extremely easy to use. Furthermore, the radiation-curable resin, which is cured by the chemical reaction described above, hardly shrinks when cured, and therefore does not crack during curing unlike the conventional paints mentioned above. It has the property of being resistant to deterioration and discoloration. It also has extremely strong chemical resistance, and therefore is resistant to deterioration and discoloration even if cleaning liquid enters the gap a during cleaning. The pattern "A" formed from the radiation-cured resin having such various excellent properties does not lose its distinctiveness even after long-term use.

FIGS. 2a and 2b show another embodiment of the present invention, in which the pattern "A" is formed on the lower surface of the cover body 13, and when the cover body 13 is attached to the groove 12, the pattern "A" is formed on the lower surface of the cover body 13. After the lower surface of "A" is brought into close contact with the upper surface of the groove 12, radiation is irradiated to harden the pattern "A". A small protrusion 13a as a spacing member is provided on the lower surface of the cover body 13 on which the pattern "A" is formed, and the pattern "A" is formed between the lower surface of the cover body 13 and the groove 1.
2. This prevents the pattern "A" from collapsing due to excessive pressure bonding to the upper surface. Of course, the height of the small protrusion 13a is
The thickness is slightly smaller than that of the pattern "A", so that when the cover body 13 is attached to the groove 12, the lower surface of the pattern "A" is in close contact with the upper surface of the groove 12 to the necessary and sufficient degree. . Note that the spacing member is the small protrusion 1 mentioned above.
3a, various shapes and forming methods can be considered, and the spacing member may be formed on the key top main body 11 side. As mentioned above, the pattern may be formed by coating on either side of the cover body or the key top body, and the important thing is that the pattern adheres sufficiently to the cover body or the key top body, and the adhesive action of the radiation-cured resin that forms the pattern is applied. , it is only necessary that the cover body and the key top body are firmly integrated.

FIG. 3 shows another embodiment of the present invention, in which 23 in FIG. 3a is a box-shaped cover body made of a radiolucent material, and is attached to an upper plate 23a and around the upper plate 23a. The inner surface 23a' of the upper plate 23a is a rough surface with unevenness. This cover body 23 is attached to the top of the key top body 21, on which the desired pattern A is coated with radiation-cured resin.
(see Figure b), and is cured by irradiation with radiation. In this way, the box-shaped cover body 23 is attached to the key top body 21.
If the cover body 23 is attached to the top of the key top body 21, the cover body 23 will be firmly fixed to the key top body 21. Furthermore, if the inner surface 23a' of the upper plate 23a that is in close contact with the upper surface of the pattern A is made rough, the radiation-cured resin forming the pattern A will flow laterally when the cover body 23 is attached to the top of the key top body 21. , it is possible to prevent the shape of pattern A from collapsing. Furthermore, the cover body 23
The light incident from above is diffusely reflected by the uneven inner surface 23a' in the portion where the pattern A is not formed, as shown by the arrow in FIG. 3c, which has the advantage of making the pattern A easier to identify.

FIGS. 4a and 4b show a perspective view and a sectional view taken along A-A of another embodiment of the cover body, in which the abdomen of the operating finger is inserted into the center of the upper surface of the cover body 33 during the pressing operation. A recessed portion 33a is recessed for the purpose. FIG. 5 shows still another embodiment of the cover body 43, in which a recessed portion 43a is formed on the upper surface of the cover body 43 to facilitate pressing operation with a fingertip.

The present invention can further be modified in various ways, including
For example, if fine metal foil such as aluminum foil is mixed into the radiation-curable resin, the pattern will be glossy and the distinguishability and aesthetics of the pattern can be improved. Further, the key top main body may have a shape other than the above-mentioned truncated square pyramid shape, a truncated cone shape, or a disc shape.

As explained above, the method for manufacturing a keytop according to the present invention includes forming a keytop from a keytop main body 1 and a colorless or colored transparent radiolucent cover 3 that covers at least the upper surface of the main body 1; A radiation-curable resin is applied to at least the upper surface of the main body 1 or a surface corresponding to that of the cover body 3 in a predetermined identification display shape, and then the two are brought into close contact with each other, and then radiation is applied to the radiation-curable resin through the cover body 3. Since the cover body 3 is easily and firmly fixed to the key top body 1, a strong key top 5 is formed.
Further, the distinguishability of the pattern A is not deteriorated, and a key top with high usability can be obtained.

[Brief explanation of the drawing]

The figure shows an embodiment of the present invention.
Figures a and b are side views during operation, Figures 2 a and b are side views during operation of another embodiment of the present invention, and Figures 3 a and 3 are side views during operation.
b, c are perspective views and side views of still another embodiment of the present invention, FIGS. 4a and b are perspective views and sectional views of still another embodiment of the present invention, and FIG. FIGS. 6a and 6b are side views of the conventional device during operation. 1, 11... Key top body, 3, 13, 2
3, 33, 43...Cover body, 5...Key top, A...Pattern.

Claims (1)

[Claims] 1 A keytop is constituted by a keytop main body 1 and a colorless or colored transparent radiolucent cover 3 covering at least the upper surface of the main body 1, and a surface corresponding to at least the upper surface of the keytop main body 1 or that of the cover 3. A method for producing a key top, in which a radiation-curable resin is applied to one of the two in a predetermined identification display shape, the two are brought into close contact with each other, and then radiation is irradiated to the radiation-curable resin through the cover body 3 to cure it.