JPH04215219A - Sheet membrane key board - Google Patents

Abstract

PURPOSE:To lighten a sheet membrane key board, and manufacture it at a low cost by forming an upper and a lower covers and a supporting panel so as to be unified integrally. CONSTITUTION:At the time of assembly of a key board, a printed substrate 5 is fitted to the back side of a supporting panel 1a of a structural member 1. Next, membrane sheets 2 having membrane switches 4 are placed on the supporting panel 1a, and a terminal 4a is inserted from a hole 1c to the back side to be connected to a connector of the printed substrate 5. Next, the printed substrate 5 is covered with a protecting cover 6. A surface sheet 3 is attached on the sheets 2 to finish a key board.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet membrane keyboard, and more particularly to a sheet membrane keyboard integrally comprising two upper and lower covers and a support panel.

In recent years, with the development of information processing equipment, various input/output devices have come to be used to exchange information between humans and machines, and have become familiar and familiar to the general public. Among input/output devices attached to various devices, keyboards are by far the most commonly used input device.

[0003] Keyboards are often used as input devices attached to parent equipment, and are divided into various types depending on the type of parent equipment, the purpose for which it is used, the location (atmosphere), etc. As seen in personal computers and word processors, the surface area of keyboards cannot be made that much smaller due to the size and arrangement of the keys, in response to the miniaturization and weight reduction of parent devices.
Demand for thinner and lighter products is increasing. Furthermore, the number of people who operate keyboards has expanded from the former experts to the general public, and there is a strong demand for lower prices for keyboards used for consumer use.

Although sheet membrane keyboards have been developed as keyboards that meet these demands, there is still room for improvement in terms of manufacturing technology.

[0005]

2. Description of the Related Art Keyboards can be classified into various types depending on the types of switches used. Among them, the keyboard that is still widely used today is a type of keyboard in which a large number of single switches called key switches are arranged and mounted on a printed circuit board, and the switching operation is performed by mechanically connecting and disconnecting the contacts of the switches. It is. However, this type of system using a single key switch has become a dying technology, and the cost reduction has reached its limit. Therefore, a sheet membrane keyboard was developed to replace it with the aim of lowering the price.

[0006] A membrane is a thin film, and a membrane switch is made by printing a conductor pattern on an insulating plastic film and overlapping it, so there is no need to line up a large number of individual switches. A sheet keyboard using this membrane switch is called a sheet membrane keyboard, and recently it has not only become cheaper but also has improved reliability, so it has been developed to the point where it is used for industrial purposes.

FIG. 3 is an exploded perspective view of a conventional sheet membrane keyboard, and FIG. 4 is a sectional view of the main parts of FIG. 3. In the figure, 1a is a support panel, 2 is a membrane sheet, 3 is a top sheet, 4 is a membrane switch, and 5
is a printed board, 7a is a lower cover, and 7b is an upper cover.

In FIG. 3, the structural members of the conventional sheet membrane keyboard include a lower cover 7a and a support panel 1a.
It is made up of three structural members that support the upper cover 7b and cover them with the upper cover 7b. The lower cover 7a and the upper cover 7b are often made of plastic molds, but the support panel 1a is made of a metal plate processed by sheet metal processing, since a strong pressing force is applied when a key is pressed. A membrane sheet 2 is placed on the upper surface of the support panel 1a, and a printed board 5 for controlling a keyboard is supported on the lower surface.

By the way, the membrane sheet 2 has a structure as shown in FIG. In other words, the lower sheet 2a
The upper sheet 2b is made of a relatively rigid polyester film having a diameter of about 80 μm and has an electrode 4b patterned by screen printing or the like. The spacing sheet 2c is also made of a polyester film with a diameter of about 100 .mu.m, and has holes 4c of several mm in diameter corresponding to predetermined key positions. Then, the membrane sheet 2 is completed by stacking the upper sheet 2b on the lower sheet 2a with the spacing sheet 2c interposed therebetween and pasting the circumference so as not to shift the position.

The electrode 4b is attached to the lower sheet 2a and the upper sheet 2.
When stacked, they intersect through the holes 4c of the spacing sheet 2c, as shown in FIG. 4(A). The lower sheet 2 facing through the hole 4b of this spacing sheet 2c
The intersection of the electrode 4b of the upper sheet 2b and the electrode 4b of the upper sheet 2b is a contact point, and this constitutes one membrane switch 4. Then, when you press the key position on the upper sheet 2b,
As shown in (B), the upper sheet 2b is recessed and comes into contact with the lower sheet 2a, and the electrodes 4b are brought into conduction to connect the switch. If you stop pressing, the upper sheet 2
b returns to its original state due to its own rigidity, and the switch is turned on and off.

For the top sheet 3, a polyurethane sheet or the like, which is highly flexible and transparent if made thin, is used. Then, the shape of the key top is printed on this top sheet 3, and a sheet of paper (not shown) on which key item names are printed is sandwiched between the membrane sheet 2 and the membrane sheet 2. . In this way, the support panel 1a
The membrane sheet 2 is placed at a predetermined position of the electrode 4b.
The printed board 5 attached to the lower surface of the support panel 1a
A sheet membrane keyboard is completed by connecting the top sheet 3 to the membrane sheet 2 and covering the top sheet 3 on top of the membrane sheet 2.

[0012] In this way, the membrane sheet 2 allows a predetermined number of switches to be installed at a predetermined position without requiring the man-hours of arranging a large number of single switches, so that it is possible to reduce the thickness and cost. It fits well with keyboards that are oriented towards price.

[0013]

As described above, a membrane sheet provided with membrane switches is useful in constructing a thin and inexpensive sheet keyboard. However, conventional sheet membrane keyboards
The structural member that forms the framework of the keyboard is divided into two upper and lower covers and a support panel. Therefore, the support panel is heavy, the number of assembly steps is required, and the cost of molding increases, which hinders the ability to make the keyboard lighter and cheaper.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a sheet membrane keyboard in which two upper and lower covers and a support panel are integrated.

[0015]

[Means for Solving the Problems] The above object has a structural member, a membrane sheet, and a surface sheet, and the structural member includes a support panel and a peripheral edge of the support panel in a normal and side sectional view. The membrane sheet includes a lower sheet and an upper sheet each having an electrode pattern, and a spaced sheet having holes provided corresponding to the positions of the keys. The switch has a membrane switch in which the electrode patterns are stacked one on top of the other and intersect with each other through the holes, the switch is made of a plastic film, and the top sheet is covered with the membrane sheet. The invention is solved by a sheet membrane keyboard made of a plastic film, said structural element being constructed in such a way that a membrane sheet is placed on the support panel.

[0016]

[Operation] While the conventional sheet membrane keyboard has a structure in which the structural parts are divided into two upper and lower covers and a support panel, in the present invention, the periphery of the support panel is supported by a frame member. That's what I do. This frame member has an upper cover above the support panel and a lower cover below the support panel. Then, a membrane sheet is placed on the support panel, and a top sheet is placed over the membrane sheet.

[0017] In this way, the two upper and lower covers and the support panel can be constructed in one piece, so the structural member becomes one,
The heavy support panel is eliminated, the number of assembly steps is reduced, and three molds are combined into one, resulting in a lighter and cheaper sheet membrane keyboard.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an exploded perspective view of an embodiment of the present invention, and FIG. 2 is a sectional view of FIG. 1, with FIG. 1A being a front sectional view and FIG. In the figure, 1 is a structural member, 1a is a support panel, 1b is a frame member, 2 is a membrane sheet, 2a
is the lower sheet, 2b is the upper sheet, 2c is the spacing sheet,
3 is a top sheet, and 4 is a membrane switch.

In FIGS. 1 and 2, a structural member 1 consists of a support panel 1a and a frame member 1b, which are made by integral plastic molding. The support panel 1a is supported by a frame member 1b so that its peripheral edge forms a substantially H-shape in front and side sectional views, and the frame member 1b corresponds to the upper and lower covers of the conventional type. In addition, support panel 1
A has a membrane sheet 2 placed on its upper surface, and a top sheet 3 is further covered thereon to form the operating surface of the keyboard. Therefore, in order to improve operability, Figure 2 (
As shown in B), it may be a sloped surface that curves downward toward the front. Furthermore, a printed board 5 is mounted on the back side of the support panel 1a.

The membrane sheet 2 is made by stacking a lower sheet 2a and an upper sheet 2b with a spacing sheet 2c in between, and a membrane switch 4 is provided at a predetermined position. In many cases, a terminal portion 4a extending from the membrane switch 4 protrudes from the end of the membrane sheet 2. In order to connect this terminal portion 4a to the printed board 5, it is necessary to turn the terminal portion 4a to the back side of the support panel 1a, and in this case, a hole 1c for this purpose is provided in the support panel 1a. Furthermore, in order to protect the printed board 5, a protective cover 6 is attached to the back side of the support panel 1a so as to cover the printed board 5.

When assembling the keyboard according to the present invention, first the printed board 5 is attached to the back side of the support panel 1a of the structural member 1. Next, the membrane sheet 2 configured in advance is placed on the support panel 1a, and the terminal portion 4 is placed on top of the support panel 1a.
A is passed through the hole 1c to the back side and connected to a connector (not shown) of the printed board 5. Next, the printed board 5 is covered with a protective cover 6. Finally, the keyboard is completed by pasting the top sheet 3 onto the membrane sheet 2.

[0022] The structural members determine the external appearance of the keyboard, and can vary depending on the customer's requests, so the shape can be modified in various ways. Further, since the force for pressing down the membrane switch is applied to the support panel, ribs can be appropriately provided on the back surface for reinforcement.

[0023]

[Effects of the Invention] Sheet membrane keyboards are keyboards that are used as attachments to low-end equipment that are particularly light, thin, short, and small, and are desired to be lighter in weight and lower in price. In contrast, according to the present invention, the upper and lower covers and metal panels conventionally used are integrally constructed and made by plastic molding. This reduces the number of structural members, making it lighter and reducing the number of assembly steps. It is also possible to reduce the cost of molds.

[0024] Therefore, the present invention makes a large contribution as a light and inexpensive sheet membrane keyboard for use in equipment such as personal computers, which are becoming increasingly lighter, thinner, and smaller.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an embodiment of the present invention.

[Figure 2] A cross-sectional view of Figure 1, where (A) is a front cross-sectional view;
Figure (B) is a side sectional view.

FIG. 3 is an exploded perspective view of a conventional sheet membrane keyboard.

FIG. 4 is a cross-sectional view of the main part of FIG. 3;

[Explanation of symbols]

1 Structural member 1a Support panel 1b Frame member 2 Membrane sheet 2a Lower sheet
2b Upper sheet 2c Spacing sheet 3 Top sheet 4 Membrane switch

Claims (3)

[Claims] Claim 1: A structural member (1), a membrane sheet (2), and a surface sheet (3), wherein the structural member (1) includes a support panel (1a) and a support panel (1a).
The membrane sheet (2) has a frame member (1b) that supports the periphery of the membrane sheet (1a) so as to form a substantially H-shape in normal and side sectional views. The sheet (2a) and the upper sheet (2b) are stacked with a spacing sheet (2c) provided with a hole (4b) provided corresponding to the position of the key, and the hole (4b)
), the membrane switch (4) is made of a plastic film, and has a membrane switch (4) in which the electrode patterns (4a) are arranged oppositely and intersectingly through the surface sheet (3).
is covered with the membrane sheet (2) and is made of a plastic film, and the structural member (1) is the support panel (1a) on which the membrane sheet (2) is placed. A sheet membrane keyboard characterized by: 2. The sheet membrane keyboard according to claim 1, wherein the structural member (1) is integrally molded using a plastic mold. 3. The sheet membrane keyboard according to claim 1, wherein the support panel (1a) of the structural member (1) is formed of an inclined surface curved so as to be lower toward the front.