JPH01232619A - Printing method for key top - Google Patents

Abstract

PURPOSE:To shorten the time for printing by coupling the space bordered by the oversurface of a board-shaped jig and a resilient sheet to a vacuum source to put it in vacuum condition, and allowing a dye to sublimate and permeate in a short while at low temp. CONSTITUTION:Rib IC of key top is fitted on a basis 3 furnished on a jig 2 and a plurality of key tops 1 are placed, and thereon a copying sheet 4 and a resilient sheet 5 are put. Further thereover, a pressure contacting surface 6A having a curvature engaging with the curvature of the oversurface of key top 1 is provided, and heat is applied while pressure is given by a heating head 6 coupled with a heat source by a pressure means. A pipe 7 is mounted on a part adjoining to the basis of the jig 2, and airtightness is held by a seal 8, and the void 9 bordered by the copying sheet 4, resilient sheet 5, and the surface of jig 2 is decompressed to a specified degree of vacuum by the vacuum source coupled with this pipe 7, and the oversurface of the resilient sheet is pressed and heated by the heating head 6, and now the dye printed on the surface of the copying sheet will sublimate at a comparatively low temp. and permeate into the surface course of the key top.

Description

DETAILED DESCRIPTION OF THE INVENTION f3-11 Industrial Application Field The present invention relates to a method for printing key tops used in typewriters and computer keyboards.

(3-21 Prior Art) In recent years, a large number of personal computers and other computers such as calculators, word processors, and laptop computers have been manufactured, all of which are equipped with keyboards; English typewriter hats are also equipped with keyboards, so there is a huge demand for them.

Each key on these keyboards has a key top, which is shown in Figure 3 ((a) is a plan view, (b) is a front view, (c) is a right side view, and (d) is a top view. It has a shape as shown in the bottom view). As shown in the figure, the key top 1 is formed by printing required characters or symbols on the upper surface LA (or on the front surface IB of the key top L as the case may be) of a resin molded product having a substantially hollow trapezoidal shape. Molded products used for such purposes are PBT (Poly Butylene Te1ephthalate).
It is molded by injection molding or the like using resin such as T or ELL, and an appropriate rib IC is provided in the inner hollow part.

In order to print desired characters or symbols on this molded key top l, a device as schematically shown in FIG. 4 (a partially cross-sectional view) has conventionally been used.

That is, in the same figure, this molded key top 1
(usually the number required for all or the main parts of a typewriter or computer keyboard) are arranged by fitting the rib IC of the key top to the pedestal 3 provided on the jig 2, and A piece of paper (hereinafter simply referred to as "transfer paper") 4 on which reverse characters, symbols, etc. are printed using dye on the top thereof, and its printed surface 4A is the top surface of the key top IA.
A sheet 5 made of an elastic material such as silicone rubber is placed on top of the sheet 5, and then the key top material is engaged with the curved surface of the upper surface IA (if necessary, with the front surface IB). It includes a pressure contact surface 6A having a curved surface that
At a predetermined temperature while being pressed by a heating head 6 having an appropriate pressing means (not shown) and connected to an appropriate heating source (not shown, heating wires etc. are usually conveniently used). When heated for a predetermined period of time, the dye printed on the transfer paper 4 sublimates and penetrates into the surface of the key top 1.

FIG. 5 is a diagram showing an example of transfer paper No. 4. In the same figure,
On the printing surface 4A of the transfer paper 4, characters or symbols to be printed on all or main key tops used in keyboards of typewriters, computers, etc. are reversed 4.
B is printed. Further, since ink containing a dye that easily sublimates at a predetermined temperature is used for printing, the dye permeates the key top 1 easily and reliably.

However, the conventional key top printing method described above had the following drawbacks.

■ Depending on the purpose of use of each type of key top, there is a resin material for key tops that is most suitable and a dye that is most suitable for printing on it, but each resin has its own softening point, and each dye has its own unique softening point. Each also has its own sublimation temperature.
Since it is not possible to print with a dye having a sublimation temperature higher than the softening point of a certain resin, there are restrictions on the combinations of resins and dyes.

■ If it is necessary to print on the front surface of the key tops, a specially shaped heating head is required to apply the transfer paper to the front surface of the key tops, which increases equipment costs.

f3-31 Problems to be Solved by the Invention The present invention solves the above-mentioned drawbacks of the conventional key top printing method and aims to select a combination of resin and dye that best matches the purpose of use of the key top. 6 i3-4) Means for solving the problem and its effect The present invention aims to provide a key top printing method that does not require high equipment costs. This was done by focusing on the fact that the pressure decreases under reduced pressure compared to normal pressure, and dye was applied to the surface of the key tops, which were manufactured by molding resin and arranged on a board-shaped jig. A sheet of elastic material such as silicone rubber is placed on top of the piece of paper on which reverse letters, reverse symbols, etc. The above-mentioned problems have been solved by improving the printing method for key tops used in keyboards of typewriters, computers, etc., in which the dye is sublimated and penetrated into the surface of the key tops by heating, as follows. . That is, it is
A key top characterized in that the heating temperature and heating time are reduced by connecting the space surrounded by the top surface of the disk-shaped jig and the elastic material sheet to a vacuum source to create a vacuum state. This is the printing method. By appropriately selecting this degree of vacuum, it is possible to lower the sublimation temperature of the dye printed on the transfer paper to below the softening temperature of the resin, making it possible to select combinations of resin and dye that would not be possible under normal pressure. Furthermore, it is also possible to shorten the printing time by keeping the temperature higher than the sublimation temperature, which is lowered under reduced pressure.

In addition, the elastic material sheet and transfer paper that cover the top surface of the key top are brought into close contact with the top surface and each side surface including the front surface of the key top by external pressure, so you can easily key the key top without using a specially shaped heating head. Printing is also possible on the front of the top. It is convenient to have all or one set of key tops arranged on a board-shaped jig used for keyboards of typewriters, computers, etc.

f3-51 example Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a diagram illustrating a key top printing method according to the present invention. In the same figure, in the case of this example as well, the rib IC of the key top is fitted into the pedestal 3 provided on the jig 2, and a plurality of key tops l are lined up, as in the conventional example. It is covered with paper 4 and an elastic sheet 5. Furthermore, as in the conventional example, there is provided a pressure contact surface 6A having a curved surface that engages with the curved surface of the upper surface LA of the key top material, an appropriate suppressing means (not shown), and an appropriate heating source ( It is heated while being suppressed by a heating head 6 connected to a heating head (not shown, but a heating wire or the like is conveniently used).

A vibrator 7 is attached to the part of the jig 2 adjacent to the pedestal 3, and an appropriate sealing material 8 is used to maintain airtightness between the outer surface of the vibrator and the hole provided in the jig. It has become. One end 7A of the vibrator communicates with a space 9 formed by the surface of the jig 2 and the surface of the elastic material sheet 5, and the other end is connected to a suitable vacuum source (not shown). If a vacuum is generated by the vacuum source connected to the vibrator 7, the transfer paper 4 and the elastic sheet 5 will be attracted to the surface of the jig 2, as shown in FIG. The space 9 formed by the surface of the material sheet is reduced to a predetermined vacuum pressure. In this situation, if the upper surface of the elastic material sheet is suppressed and heated by the heating head 6, the dye printed on the surface of the transfer paper will sublimate at a relatively low temperature corresponding to the vacuum pressure, and will be transferred to the surface of the key top. Penetrate.

f3-61 Effects of the Invention The present invention creates a vacuum in the space formed by the surface of a disk-shaped jig and the surface of an elastic material sheet when sublimating and infiltrating the characters or symbols on the transfer paper onto the surface of the key top. When maintained, the following excellent effects can be achieved.

■ Characters can be printed on resin with a low softening point using a dye with a sublimation temperature higher than the softening point, so any combination of resin and dye that matches the intended use of the key top can be used. It became possible to

■ Printing time can be shortened by heating under reduced pressure to a temperature close to the sublimation temperature under normal pressure.

■ Since there is no need to use a heating head with a special shape, equipment costs can be saved.

[Brief explanation of the drawing]

Figure 1 is a diagram illustrating the key top printing method according to the present invention, Figure 2 is an enlarged diagram showing the state of close contact between the elastic material sheet and the transfer paper when a vacuum is applied, and Figure 3 ((a) is a plan view, (b) is a front view, (c) is a right side view, (d) is a bottom view) is a diagram illustrating the shape of the key top, and FIG. 4 is a diagram illustrating a conventional printing device. FIG. 5 is a diagram illustrating a transfer paper. ■...Key top material IA...Top surface 1B...Front surface 1c...Rib 2...Jig 3...Pedestal 4...Transfer paper 4A...Printed surface 4B...Character, symbol 5...・Sheet 6... Heating head 6A... Pressure contact surface 7... Vibrator 7A... One end

Claims (1)

[Claims] (1) A piece of paper on which reverse letters, reverse symbols, etc. are printed using ink containing dye is adhered to the surface of the key tops, which are manufactured by molding resin and arranged on a board-shaped jig. A typewriter in which a sheet of elastic material such as silicone rubber is placed on top of the key top, and the sheet is further heated to a predetermined temperature while being pressed by a heating head connected to a heat source, so that the dye sublimates and penetrates into the surface of the key top. In a method for printing key tops used in keyboards of computers, etc., heating is performed by connecting a space surrounded by the top surface of the board-shaped jig and the elastic material sheet to a vacuum source to create a vacuum state. A printing method for key tops that is characterized by lowering the temperature and allowing the dye to sublimate and penetrate in a short period of time.