JPS63318030A - Soft keyboard - Google Patents

Abstract

PURPOSE:To prevent the pollution, abrasion, corrosion or the like of an operating unit caused by the repeated use and improve the merchandise value and reliability by forming the operating face of a key top with a pressure conductive elastic material, short-circuiting an electrode with the other face, and providing a thin film on the surface of the operating face. CONSTITUTION:A plate-shaped pressure conductive sponge 10 mixed with conductive metal grains 11 inside and having flexibility and load-displacement characteristic is fitted to the upper face of a substrate 1 with electrode patterns, and the surface of the substrate 1 is coated with an insulating film 5 except for a contact section 4. When a certain key is selected and the operating face of the pressure conductive elastic material 10 is pressed with a finger tip, the pressed portion of the pressure conductive elastic material 10 is compressed, and its electric resistance is decreased. Multiple electrode patterns provided on the substrate 1 are short-circuited at the pressed key position, and the selected key is detected. The pollution, abrasion, corrosion or the like of an operating unit caused by the repeated use are prevented, the merchandise value is improved, and the adverse effect such as malfunction can be excluded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a keyboard, and more particularly to a soft keyboard that performs switching by short-circuiting between electrodes using conductive sponge, rubber, or other elastic material when pressurized. .

[Conventional technology]

Conventional keyboards have different contact structures depending on the type, such as mechanical types, conductive rubber types, membrane type types, and capacitance variable type types, but in all cases, the contact structure is at the tip of the back of the rigid key top. A movable contact is provided on the side of the base plate, and a fixed contact is provided on the substrate at a position facing the movable contact.

According to the above-mentioned conventional keyboard, there is a guide part for moving the rigid key top up and down, a spring for urging the key top upward except when it is operated, and a spring that prevents the key top from being removed when the key top is pressed upward. Furthermore, an outer frame for covering these mechanisms and contact portions and protecting them from the outer bottom is required at a minimum, and the number of parts is large and it is necessary to assemble these parts precisely.

For this reason, there is a limit to how much the keyboard can be made smaller and thinner as a whole, and because there are many rigid parts such as the key top and outer frame, it is also heavy, which is a major bottleneck in reducing the size and weight of personal information devices that are highly portable. was. In addition, since the number of parts is large, the manufacturing cost is high, and in order to use it in personal equipment that strongly demands low cost, it is necessary to further reduce the price.

In order to improve these points, a keyboard as shown in FIG. 8 has been commercialized in which the switching function and the spring function are integrated and the switch mechanism is greatly simplified compared to the conventional keyboard. The keyboard shown in FIG. 8 consists of keys 1, knobs 21, and 21, which are operated with the fingertips. A rubber keyboard 2 that integrates a cushion part 22 that provides a click feeling when keys are operated and plays the role of a spring in a conventional keyboard, and conductive rubber contacts 23 made of silicone rubber and conductive carbon.
4, a substrate 26 having a patterned electrode 25 on its surface, and a front panel 27.

This type of technology is described in the Japan Office Machinery Manufacturers Association, "Office Machinery J No. 109, January 1986 issue No. 29.
There is a description on page 35.

[Problem that the invention seeks to solve]

According to the keyboard shown in FIG. 8 above, a large number of conductive keys can be arranged and integrally molded on one rubber sheet.
With conventional keyboards, the number of parts required for each key can be greatly reduced, reducing costs. Further, there is no need for precise assembly of the large number of parts mentioned above, and the keyboard can be easily made smaller and thinner, and is already used in many small desk-top electronic computers.

However, according to the keyboard shown in FIG. 8 above, although a click feeling can be obtained due to the shape of the cushion portion 22, if a fingertip is pressed at a position off the center of the key top 21, the entire key tends to fall sideways. However, there was a problem in that the contact part made unstable contact and the operation feeling was poor.

An object of the present invention is to form a keyboard with a simple structure and a small number of parts, and to create a personal information device that can be easily made smaller and thinner, has good operability, is lightweight, and can be manufactured at low cost. To provide a suitable and highly reliable keyboard, to prevent soiling, abrasion, corrosion, etc. of the operation part due to repeated use, and to maintain the beauty of the design and maintain the product value.
Another purpose is to eliminate adverse effects such as malfunctions caused by these.

[Means for solving problems]

The above purpose is to utilize a sponge, rubber, or other elastic material that becomes conductive under pressure (hereinafter referred to as a pressure conductive elastic material), and to use a surface of the pressure conductive elastic material that is similar to a conventional keyboard. This is achieved by forming an operation surface corresponding to the key top in the method, short-circuiting electrodes on the other surface to detect input keys, and providing a thin film on the surface of the operation surface.

[Effect]

When a certain key is selected and the operating surface of the pressurized conductive elastic material is pressed with a fingertip, the pressed portion of the pressurized conductive elastic material is compressed, and the electrical resistance of the pressed portion is reduced. Thus, a plurality of electrode patterns provided on the substrate are short-circuited at the location of the pressed key, and the selected key is detected.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. paper-
Two types of electrode patterns, electrodes 2 and 3, are formed on the upper surface of a substrate 1 made of phenol resin or the like by etching a copper foil film or the like. The electrode pattern includes
As shown in FIG. 4, a contact portion 4 is provided where the electrodes 2 and 3 are close to each other, and the surface of the substrate 1 other than the contact portion 4 is coated with an insulating coating 5. Such contact portions 4 are provided on the substrate 1 in the number of required keys, and are arranged in correspondence with the arrangement of each key on the keyboard. FIG. 3 shows an example of a key arrangement and an electrode pattern.

On the upper surface of the substrate 1 having the electrode pattern as described above,
As shown in FIG. 1, conductive metal particles 11 are mixed inside,
A plate-shaped pressurized conductive sponge 10 having elasticity and load-displacement characteristics as shown in FIG. 9 is attached.

The characteristic shown in Figure 9 is the long-term use of the keyboard.

This characteristic is considered ideal from an ergonomic point of view, as it prevents impacts to the fingertips during high-speed input and erroneous input due to unstable finger movements.

The pressurized conductive sponge 10 is usually an insulator with a resistance of several MΩ, but it is easily compressed by pressing it with a fingertip, and the conductive metal particles 11 mixed inside come close to each other and the part It has the characteristic that the resistance value of the resistor becomes as small as several ohms.

On the upper surface of the pressurized conductive sponge 10, each key is divided by a notch 12 at the boundary with the adjacent key, and the entire upper surface including the notch 12 is covered with an insulating thin film. Coated with 18. Letters, numbers, codes, etc. of each key are printed on the surface of the thin film 18.

In FIG. 3, the electrodes 2 corresponding to the number of keys are connected to a positive potential, and the electrode 3 shared by one electrode is connected to a negative potential.

The operation of detecting an input key by the keyboard configured as described above will be described below.

When you press the pressurized conductive sponge 10 of the key you want to input with your finger, the pressed part of the pressurized conductive sponge 10 is compressed, and the electrical resistance of the pressed part becomes small. The connected electrodes 2 and 3 are short-circuited. Therefore, by detecting the portion where the potential of the electrode 2 becomes a negative potential, the input key can be detected.

In addition, when pressing the pressurized conductive sponge 10 with your finger in the above manner, press the center of the area divided by the notches 12 on the surface of the pressurized conductive sponge 10 (7) to prevent adjacent keys from being input. Bye. However, even if you accidentally press between the keys, etc., because the insulating coating 5 is interposed between the pressurized conductive sponge 10 and the substrate 1, there will be no contact area other than the contact portion 4 on the substrate 1 in that area. Even if an electrode pattern exists, there will be no electrical short circuit, and a key different from the selected key will not be detected, so there will be no malfunction.

As another embodiment of the present invention, as shown in FIG. 5, a protrusion 17 is provided on the bottom surface of the pressurized conductive sponge 1o in the above embodiment at a portion that comes into contact with the contact portion 4 provided on the substrate 1,
The pressurized conductive sponge 1o and the substrate 1 are connected to the protrusion 17.
An example of a keyboard having a structure in which contact is made only through the contact portion 4 can be given.

According to the second embodiment, the insulating coating 5 in the first embodiment is not required, and the structure is simpler, resulting in lower component costs and manufacturing costs.

Further, as a further embodiment of the present invention, as shown in FIG. 6, if one electrode 2 is provided on the substrate 1 and the other electrode 13 is arranged inside the pressurized conductive sponge 1o, the substrate The electrode arrangement on the keyboard is extremely simple, leaving more space between the electrodes and at the contact points, allowing the entire keyboard to be further miniaturized.

〔Effect of the invention〕

According to the present invention, a keyboard can be formed with a simple structure and a small number of parts, and can be easily made smaller and thinner, and can be manufactured lightweight and at low cost. , thin and lightweight.

It is possible to provide a keyboard with good operability and high reliability, which is particularly suitable for use in personal information equipment that is compact and frequently used as a portable device.

In particular, according to the present invention, by providing a thin film on the surface of the pressurized conductive elastic material, the surface of the keyboard can be colored, and the color scheme can be improved.
Designs such as character printing can be easily displayed, and the pressurized conductive elastic material is protected from dirt and abrasion of the operation part due to repeated use.
It can prevent corrosion, maintain the aesthetic appearance of the design, and increase product value.

In addition, there is no need to worry about the characters displayed on the control panel being difficult to read due to damage to the control panel as described above, causing momentary hesitation or incorrect input, which further improves input operability. .

Furthermore, by applying the coating using an insulating material, there is a risk of current leakage to the human body during operation, contact with conductive substances, etc., which may cause malfunctions or malfunctions, resulting in the loss of important data, or the loss of important data. There is no need to worry about destroying the input program, making it possible to create a more reliable product.

[Brief explanation of drawings]

FIG. 1 is an enlarged sectional view showing an embodiment of the present invention, and FIG. 2 is a perspective view showing an example using the soft keyboard of the present invention.
3 and 4 are plan views showing an example of the electrode pattern arrangement on the substrate, FIGS. 5 and 6 are sectional views showing other embodiments of the present invention, and FIGS. 7 and 8 are FIG. 9, an enlarged cross-sectional view of a conventional keyboard, is a diagram showing ideal load-displacement characteristics of the keyboard. 1... Substrate, 2... Electrode, 3... Electrode, 4...
Contact portion, 5... Insulating coating, 10... Pressurized conductive sponge, 11-... Conductive metal particles, 12... Notch, 1
3...-Electrode, 17 heat 1 Figure 1... H-u deficiency 2... '4 end 43
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8. ...thin film%4(2) muscle s121

Claims (1)

[Claims] 1. One surface forms an operation surface, the other surface is placed on a substrate, and a pressurized conductive elastic material with a thin film provided on the surface of the operation surface short-circuits multiple electrodes to perform key input. A soft keyboard characterized by: