JPH09219128A - Manufacture of key top - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obviate troublesome light shielding printing and pattern printing or painting in a three-dimensional shape after being molded by performing printing of a key top in a condition of a plane sheet. SOLUTION: A light shielding film is formed on a plane on a separative sheet 1 by printing by light shielding ink 2, and color plane printing 3 of a display part is performed in a prescribed position on it, and a printed light shielding film sheet 5 is placed on a metal mold 6 on which a large number of air vents are performed, and is vacuum-sucked, and the light shielding film sheet 5 is attracted to a metal mold inner wall surface. In this case, it may be positioned in a female mold by a vacuum suction type pushing-in jig, and afterwards, a material such as silicone is also put in this metal mold, and is integrally molded, and a desired pattern 8 is formed on a completed key top surface of a three-dimensional shape by laser beam machining.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a key top of a switch incorporated in an input section of a telephone, an audio device, a television, a video, a facsimile, a copying machine, an in-vehicle device or the like.

[0002]

2. Description of the Related Art A conventional key top manufacturing method is to first form a key top shape, then white paint the entire surface of this three-dimensional shape, and then print a color such as a display pattern on the top surface, and then The entire surface is painted black for shading, and the top surface is laser cut to form the desired pattern.

As another manufacturing method, there is a method in which the display section is put in a mold in advance and then molded.

[0004]

In the conventional manufacturing method, the three-dimensionally molded key tops are painted and printed. Therefore, the three-dimensional top surface as well as the four side surfaces and three-dimensional surfaces are first painted. In order to paint the gap between the parts, the ink jet nozzle must be swung in all directions, and equipment and space for that purpose are required. Further, it is difficult or extremely time-consuming to uniformly coat each surface of the solid body and the gaps therebetween.

And, a wide working space is required.
There is a high risk of dust adhesion and a lot of defective products are discharged. Further, if the coating is not made uniform, the thickness will vary, resulting in defective cutting in laser processing in a later step.

In addition, when the top surface is printed after being formed into a three-dimensional shape, the top surface of various heights must be printed.
Even printing is impossible, or printing must be repeated many times, which takes time.

The method of inserting the display portion into the mold in advance requires a clamp for aligning the display portion film, which is very problematic in terms of accuracy and may cause film distortion during molding. is there.

[0008]

According to the present invention, light-shielding printing and pattern printing are performed in the state of a flat sheet before forming into a three-dimensional shape, and in the three-dimensional shape, only pattern processing by laser cutting is performed. The troublesome painting was eliminated, the printing accuracy was improved, and the number of steps was greatly reduced. Therefore, since printing can be performed in the state of a flat sheet, the degree of difficulty is large and the printing accuracy is high as compared with printing after forming a three-dimensional shape. Further, it becomes possible to print in advance the groove 9 between the respective key surfaces, which is impossible after the molding.

Further, since it is possible to process by printing instead of painting, there is no need for a large space for painting, no defects due to dust adhesion, no pollution due to ink scattering,
Moreover, uniform printing can be achieved even on the side surface and the gap. Moreover, the manufacturing process can be greatly shortened.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a solid black print is formed with a light-shielding ink 2, for example, a silicone ink, on a release sheet 1 such as a fluorine film to form a light-shielding film, and the light-shielding film can be formed on the release sheet 1 as required for design. Accordingly, white solid printing or desired color printing 3 as a display portion is performed at a predetermined position corresponding to the key top, and the printing process is completed. At the time of this printing, the frame 4 is adhered to the periphery.

Next, the release sheet 1 is peeled off, and the light shielding film sheet 5 is placed on the mold. At this time, the light shielding film sheet 5 is stretched by the frame 4.

The release sheet 1 is required to have heat resistance because heat is expected to be applied when the ink is cured, and the light-shielding film is easily peeled off from a silicone-based or fluorine-based release sheet.
Imide type is preferable. Since the light-shielding film is stretched and sucked, it is preferably an elastic film of silicone-based, urethane-based, acrylic-based, epoxy-based, other synthetic rubber-based, etc., which is generally 300% or more stretchable. Although there are printing, painting, etc., the printing method is preferable from the viewpoint of management of the light-shielding film and working space. Also, the release sheet 1
Before forming the light-shielding ink 2 as an elastic light-shielding film on the upper surface, a reinforcing film may be formed with a transparent ink as needed to improve the film strength. When using a key sheet with a key top as a key switch for mobile phones, etc., this reinforcing film may cause deterioration of product quality due to light leakage from the lower light source due to abrasion of the key top corners in actual use. Therefore, after forming the key sheet, it is provided for the purpose of improving the wear resistance of the surface. The abrasion resistance of the surface depends on the thickness of the reinforcing film and the shape of the key top, but the durability is about 1.5.
~ 2.0 times improved.

As the mold 6, a generally used vacuum suction mold is used, and a material having fine holes if necessary is used, and the printed sheet 5 is sucked through the mold. For example, since the silicone sheet 5 formed of silicone ink is usually stretchable by 300% or more as described above, it is naturally stretched and sucked into each fixed position of the mold to be preformed.

Thereafter, while leaving the printed sheet 5 in the mold 6, a material 7 such as silicone is put into the mold, and then the top surface of the key top is laser-processed to display characters, patterns 8, etc. Create a section.

An illuminated key top can be manufactured by using a translucent ink in place of the black, gray, or other dark color light-shielding ink.

As shown in FIG. 1, the metal mold used for vacuum suction molding has a large number of fine holes on the side surface as well as the bottom surface of each cavity of the metal mold, or the material of the metal mold. As a porous material, the printing sheet 5 placed on the mold is sucked and preformed.

As another mold, as shown in FIG. 2, a suction path 10 communicating with each cavity 9 is formed on the surface of the mold 6 instead of a method of sucking from the wall surface of the cavity, and this is made into a suction hole 11. Some are connected. When suction is started, the inside of each cavity 9 becomes a negative pressure, and the print sheet 5 placed on the upper part is adsorbed and preformed in the shape of the mold.

At this time, in order to ensure airtightness, it is preferable to arrange the packing 12 under the peripheral frame 4.

Further, in order to perform the positioning of the color-printed portion of the display portion on the mold more precisely, a male-shaped convex portion 13 that enters the cavity of the mold as shown in FIG. 4 is provided. Using the suction-type pushing jig 14 that is provided, the printing sheet 5 is adsorbed and held, the pushing jig 14 is aligned in the die 6, and suction of the die 6 is started, and at the same time, the pushing jig 14 is pressed. By releasing the suction, the printing sheet 5 can be precisely positioned at a predetermined position of the mold 6 and sucked.
After that, the pushing jig 14 is removed, and an elastic material such as silicone rubber, natural rubber or other synthetic rubber is put in and integrally molded.

Further, according to the above-mentioned invention, the display portion of characters, patterns, etc. is formed after the three-dimensional molding. However, when the light-shielding film is formed on the release sheet with the light-shielding ink, the characters, patterns, etc. are previously formed. Since the portion excluding the display portion is printed with the light-shielding film, and all the processing relating to the display portion such as characters and patterns by laser processing after three-dimensional molding can be performed on the flat sheet, the work can be very easy.

Further, after the printed light-shielding film 5 is adsorbed in the mold, when a material such as silicone is put in to mold the key top, as shown in FIG. By inserting 15 and molding, as shown in FIG. 7, it is possible to manufacture a key top having a change in which only the upper portion of the key top 16 is shielded from light.

Furthermore, as shown in FIG. 8, before the printed light-shielding film 5 is adsorbed in the mold 6, a heat-resistant transparent resin that is preformed, for example, a fluorine-based resin that does not deteriorate due to the temperature of the inserted mold, A keytop molded product 17 made of a thermoplastic resin such as polysulfone or polyimide, or a thermosetting resin such as phenol, melamine, epoxy, silicon or diallyl phthalate is inserted, and then light is shielded. By adsorbing the film 5 and thereafter molding it in the same manner as in the other examples, a key top in which the top surface of the key top is hard, the base portion has elasticity, and the character surface is covered is not erased. It becomes possible to obtain.

[Brief description of drawings]

1 is a diagram showing the manufacturing process FIG. 2 is a cross-sectional view showing another mold. 3 is a diagram showing the plane of FIG. 4 is a cross-sectional view showing a pushing jig. Figure 5 Cross-sectional view with the pushing jig set. 6 is a cross-sectional view of the inserted middle mold. Figure 7 Key top view molded using a medium mold. FIG. 8 is a cross-sectional view of inserting the keytop molded product into a mold and molding.

[Explanation of symbols]

 1 Release Sheet 2 Light-Shielding Ink 3 Color Printing 4 Frame 5 Light-Shielding Film Sheet 6 Mold 7 Silicone 8 Pattern 9 Cavity 10 Suction Path 11 Flat Sheet 12 Packing 13 Convex 14 Jig 15 Printing Sheet 16 Keytop 17 Molded Product

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical display location // B29K 83:00 B29L 31:34 (72) Inventor Nakajo Masaru Iwatsuki-shi, Saitama Prefecture Table Jionji Temple 978-1 Fuji Polymatech Co., Ltd. Technical Center (72) Inventor, Moto Yamauchi Oji Jinji Temple, Iwatsuki City, Saitama Prefecture 978-1 Fuji Polymatech Co., Ltd., Technical Center (72) Inventor Nobuaki Oji Iwatsuki, Saitama Prefecture 3-4-38 Ichijo-Minami Fuji Chemical Co., Ltd.

Claims (7)

[Claims] 1. A light-shielding ink is used to form a light-shielding film on a release sheet to form a light-shielding film, and a display portion is placed at a predetermined position and color-printed in a desired color. The light-shielding film sheet that was peeled off and printed was placed on a mold having a large number of vent holes, vacuum suction was performed, the light-shielding film sheet was adsorbed on the inner wall surface of the mold, and a material such as silicone was placed in the mold. A key top manufacturing method in which a desired pattern is formed by laser-machining the surface of a three-dimensional key top that has been put into one body and molded. 2. A light-shielding ink is used to form a light-shielding film by planar printing except for display characters and pattern portions on the release sheet to form a light-shielding film, which is then color-printed in a desired color, and then the release sheet is applied. The light-shielding film sheet that was peeled off and printed was placed on a mold having a large number of vent holes, vacuum suction was performed, the light-shielding film sheet was adsorbed on the inner wall surface of the mold, and a material such as silicone was placed in the mold. A method of manufacturing key tops that are integrally molded. 3. The key according to claim 1, wherein vacuum suction is performed on the light-shielding film sheet by using a mold having a suction passage formed in the surface of each cavity. Top manufacturing method. 4. The method according to claim 1, wherein only the upper part is shielded from light by molding by inserting a middle mold into a mold on which a printed light-shielding film is placed. The key top manufacturing method described in. 5. The key top manufacturing method according to claim 1, wherein the surface sheet is formed of a transparent ink instead of the light-shielding ink. 6. The printed light-shielding film sheet is adsorbed and held by a pushing jig having the same shape as that of the male die and having suction holes formed at appropriate intervals so as to be positioned in the female die. 5. The method for producing a key top according to 1 of 5. 7. The printed light-shielding film is adsorbed after a key-top molded product made of a heat-resistant transparent resin which has been molded in advance is inserted into a mold. 1. The method for manufacturing the key top according to 1.