JPH0740450B2 - Keyboard board and manufacturing method thereof - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a keyboard panel having a simple structure, which is used in a computer, a calculator, a word processor, etc., and a manufacturing method thereof.

(Prior Art) The following are known as conventional keyboard panels, and each has the following drawbacks.

Push button made of urethane or silicone rubber,
It is built into a separately molded panel.

It is necessary to prepare at least two kinds of parts as this part, the manufacturing cost is high, and dust easily enters between the panel and the button.

Flexible printed circuit is used for the circuit part, and it is built into a separately molded panel.

This one also has the same drawbacks as.

A circuit and display are provided by printing on a plastic film.

This has the drawback that a plate made of synthetic resin is further required to form the panel itself.

The panel is made of ABS resin and the buttons are made of urethane resin in two colors.

This is complicated to mold and the mold is expensive.

(Problems to be Solved by the Invention) In the present invention, in the above-mentioned conventional technique, the number of parts is large, and the drawback of requiring a step of manufacturing each part separately and a step of combining them is solved. The purpose is to do.

(Means for Solving Problems) According to the study by the present inventor, a synthetic resin sheet provided on the pattern surface side of a keyboard is used, and this sheet is molded using a special mold during injection molding, It has been found that the above-mentioned drawbacks can be solved by opening a molded body under the decorating sheet at a portion corresponding to each key and providing a protrusion in the center of the portion exposed from the opening of the decorating sheet.

1 of the present invention is a "keyboard panel integrated with a chassis and a case, in which a painting sheet is provided on the front surface of a panel-shaped synthetic resin molded body having through holes in portions corresponding to keys. It is laminated and has the display part of the keyboard on the front side of the painting sheet, and the part corresponding to the key is convex toward the front side, and the synthetic resin molding on the back side of the painting sheet The keyboard panel characterized in that it has a protrusion made of a synthetic resin in a portion exposed from the through-hole portion of the synthetic resin molded body separately from the periphery thereof. No. 2 is a "method of manufacturing a keyboard panel integrated with a chassis and a case, in which a painting sheet with a keyboard display portion is provided on the front surface of a thermoformable synthetic resin sheet. Heat on the surface shape Then, the female and male molds have a clearance corresponding to the thickness of the painting sheet at the peripheral portion of each key of the painting sheet, and correspond to each key. In the portion, there is a concave portion on the female side, inside the peripheral edge of each key, there is a columnar cavity on the male side, and
In other parts, a keyboard panel having a cavity shape is used, a molding sheet is placed in a mold, and injection molding is performed from the back side ".

FIGS. 1 and 3 show one embodiment of the present invention, and in this figure, an example applied to a keyboard of a calculator is shown.

FIG. 1 is a perspective view thereof, and a synthetic resin molded body 1 constitutes the upper half of a chassis (case) of a calculator, and a display portion 2 of a keyboard is provided on the surface by printing.

The keyboard panel of the present invention will be described with reference to FIG. 2 showing a case where the painting sheet of the key portion is raised upward to form a convex portion, but not the convex portion. Figure 2 shows the first
1 is a cross-sectional view of what is shown in the drawing, which is composed of a synthetic resin molded body 1, a laminated body with a decorating sheet 3, and a protrusion 7.

The painting sheet 3 is a laminate of the base sheet 4 and the transparent protective sheet 5 when viewed in more detail. Between the sheets 4 and 5, a character, a number, Display printing unit 6 for decimal point and arithmetic symbols
have.

In the synthetic resin molded body 1, the through-hole 8 is formed in each portion of the painting sheet 3 where the key areas of the display portion are formed on the front side.
Are formed.

Then, in the portion where the painting sheet is exposed from the through hole 8 to the back surface, the projecting portion 7 is laminated on the painting sheet 3.

The projecting portion 7 is for conducting the contact of a circuit placed under the upper chassis for the calculator shown in the figure. Therefore, depending on the structure of the other circuit, the sectional shape, diameter, height, etc. Can be freely designed. It is also possible to provide a part of an electric circuit such as a conductive circuit or a contact circuit at the tip of the protruding portion 7. For example, a silver-based paste, copper or nickel as a metal, or a conductive plastic sticking , Metal partial vapor deposition, partial laminating, etc.

FIG. 3 is a cross-sectional view of the keyboard panel of the present invention in which the key portion is convex toward the front side, and the painting sheet of the key portion is raised above that of FIG. Are different, but others are the same.

Therefore, if the structure shown in FIGS. 1 to 3 is used,
Since the upper side of the calculator can be composed of a single part, there is an advantage that the work of manufacturing each part separately and then assembling it can be omitted, the cost can be reduced, and the labor of managing the parts can be reduced. Occurs.

The material of each part of the keyboard panel of the above invention and the manufacturing method of the above keyboard panel will be described below.

The painting sheet 3 provides a display portion on the surface of the molded body. As a general rule, the painting sheet 3 need only have a display-printed portion on the front surface of the thermoformable synthetic resin sheet, but in order to prevent the front-side display-printed portion from being worn, the display-printed portion is not necessary. It may be formed by using a curable ink and then cured after forming, or a protective layer made of a transparent synthetic resin may be provided on the front surface so as to cover the display printing portion.

The sheets that make up the painting sheet can be thermoformed, and it is advisable to select one that can withstand repeated pressing (for example, 500,000 times). Specifically, polyurethane, polycarbonate, polyethylene terephthalate, polychlorinated Sheets of vinyl, polysulfone, etc. are used alone or laminated as shown in FIGS. 2 and 3 to form a painting sheet.

In order to improve the repeated bending strength, a thin sheet (for example, 5 to 50 μm) having good bending strength may be laminated on the front surface or the back surface of the above-mentioned sheet having good moldability.

The thickness of the painting sheet 3 is preferably 100 μm to 500 μm.

The display printing unit 6 of the painting sheet can be provided by a known printing method.

The painting sheet 3 depends on the shape of the final molded body,
Usually, prior to injection molding, it is preferable to form a molded sheet in advance so as to match the shape of the mold. The thermoforming method of heating and shaping the sheet is suitable as the molding method at this time, and each method of vacuum molding, pressure molding, or vacuum pressure molding is used, and it is necessary to reproduce the details of the shape of the mold. Rather, it can be approximate.

The molded sheet obtained by thermoforming is set in the mold by aligning the printing parts on the front and back sides with the mold, and the molten resin is injected into the mold from the back surface to mold.

As the die used for injection molding, the die illustrated in FIG. 4 is used for the keyboard panel shown in FIG. 2, and the die used for the keyboard panel of the present invention is a convex portion on the front side. The mold illustrated in FIG. 5 may be used. Mold 10
For the female mold 11 where the shape of the final molded product is determined,
An ordinary one may be used, and if necessary, a female mold may have a vacuum drawing hole for use as a mold in vacuum molding or the like.

Regarding the male die 12, in order to prevent the injection molding resin from adhering to the back side of the peripheral edge of each key of the keyboard panel, the convex portion 13 is provided in the portion corresponding to the peripheral edge of each key of the male die, and those There is only a clearance 14 between the female mold and the male mold in which the painting sheet is inserted, and both molds are almost in close contact with each other to prevent the molten resin from flowing during injection molding. The inside of the peripheral edge of each key has a columnar cavity shape so that the required molten resin can flow in, and the other portion has a keyboard panel-shaped cavity shape. When the portion corresponding to each female key is the recessed portion 15, it is preferable that the corresponding portion of the male type is shaped to match the recessed portion.

The molten resin used for injection molding, as a thermoplastic, ABS resin, polystyrene resin, acrylic resin such as polymethylmethacrylate resin, acrylonitrile-styrene copolymer resin, polyvinyl chloride resin,
A noryl resin, a polycarbonate resin, or the like, or a thermosetting resin such as a melamine resin or a urea resin can be used.

The above-described keyboard manufacturing method of the present invention can be performed by using a vacuum / compressed air (vacuum molding, compressed air molding, or vacuum compressed air molding) apparatus and an injection molding apparatus.

(Effects of the Invention) In the keyboard panel of the present invention, since the synthetic resin molded body is opened in the lower side of each key, there is only a painting sheet at each key portion, and when pressed with a finger, the portion bends. Although it works as a switch, the keyboard panel is integrated with the chassis (case), so the number of parts is small, and the keyboard and chassis supporting it can be used as the case. .

Also, according to the manufacturing method of the present invention, it is possible to efficiently manufacture the keyboard panel having the above characteristics.

(Example) A design sheet was created by printing the design of each key of the calculator on the front side of a polyvinyl chloride resin sheet having a thickness of 200 μm.

The above decorating sheet was attached to an injection molding device with a winding supply and winding device, and the decorating sheet was fed to the front surface of the female mold, aligned, and fixed.

After molding the painting sheet by vacuum / pneumatic molding using a female mold, the mold is clamped and molten ABS resin is injected from the back side of the painting sheet to be integrated with the painting sheet to obtain a molded product. , Trimmed and got the upper half case of the calculator.

After being used as a calculator, this product does not change its restorability even if each key is repeatedly pressed 500,000 times or 1,000,000 times, and there is no defect in appearance.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of a keyboard panel of the present invention,
2 and 3 are cross-sectional views of the one shown in FIG. 1, and FIGS. 4 and 5 are cross-sectional views of the mold used in the method of manufacturing the keyboard panel. 1 …… Synthetic resin molding 2 …… Display part 3 …… Painting sheet 4 …… Base material sheet 5 …… Protective sheet 6 …… Display printing part 7 …… Projection part 8 …… Through hole 10 …… Mold 11 …… Female 12 …… Male 13 …… Convex 14 …… Clearance 15 …… Concave 16 …… Cavity

Claims (2)

[Claims] 1. A keyboard panel integrated with a chassis and a case, wherein a painting sheet is laminated on a front surface of a panel-shaped synthetic resin molded body having a through hole in a portion corresponding to a key. The front surface of the painting sheet has a keyboard display part, and the portion corresponding to the key is a convex portion toward the front side, and the synthetic resin molding on the back surface of the painting sheet penetrates. A keyboard panel, characterized in that, in a portion exposed from the hole, a protrusion made of synthetic resin is provided separately from the periphery of the synthetic resin molded body. 2. A method of manufacturing a keyboard panel integrated with a chassis and a case, wherein a painting sheet provided with a keyboard display portion on the front surface of a thermoformable synthetic resin sheet is used as a keyboard panel. A molded sheet is formed by thermoforming into a surface shape, and then, as a die, a female die and a male die have a clearance corresponding to the thickness of the painting sheet at the peripheral portion of each key of the painting sheet. The part corresponding to the key has a concave part on the female side, the inside of the peripheral part of each key has a columnar cavity on the male side, and the other parts have a cavity in the shape of the keyboard panel. A method for manufacturing a keyboard panel, comprising using a shaped sheet, placing a molding sheet in a mold, and performing injection molding from the back side.