JPS6063655A - Electronic calculator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic desk calculator, and more particularly to an electronic desk calculator with a simplified structure.

BACKGROUND OF THE INVENTION With advances in electronic technology, electronic desktop calculators have become smaller and lighter, and extremely portable calculators have become widespread. With the spread of this type of calculator, the environments in which it is used have expanded, and there are more opportunities for it to be used in environments where it is exposed to water droplets or where there is an extremely large amount of dust.

However, the structure of the keyboard section of a conventional calculator is as shown in FIG.

That is, in FIG. 1, reference numeral 1 indicates a key top, and this key top 1 is guided so as to be movable up and down by a key top guide 2 formed on the case side of the calculator. A contact rubber 3 made of an elastic material such as rubber is arranged on the lower side of the key top 1, and has a habit of always moving upward with respect to the key top 1. In addition, when the key top 1 is pressed down, the contact 3a formed on the lower surface of the contact rubber 3 comes into contact with the contact formed on the printed circuit board 4, and the key is operated manually.

However, when the structure shown in Figure 1 is adopted, a small gap inevitably occurs between the key top 1 and the key top guide 2, allowing water droplets and dust to enter the main body of the calculator and damage the electronic circuit. There were drawbacks such as short-circuiting and key top 1 getting stuck and not functioning.

Therefore, in order to eliminate such shortcomings,
As shown in FIG. 2, a structure was adopted in which the front surface of the key top l was covered with a transparent elastic coating 1a.

If such a structure is adopted, the entire surface of the keyboard section is covered with a transparent elastic coating, making it difficult for water droplets and dust to enter, making the keyboard completely waterproof and dustproof.

However, taking the trouble to coat with a trimonolytic film in this way complicates the structure and leads to an increase in cost.

The present invention has been made in order to eliminate the above-mentioned conventional drawbacks, and an object of the present invention is to provide an electronic desktop calculator that is equipped with waterproof and dustproof functions and has an extremely simplified structure.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

3 and 4 illustrate an embodiment of the present invention, in which the top surface of an electronic desk calculator a (hereinafter referred to as a calculator) according to the present invention is covered with a cover made of an elastic member such as silicone rubber. The parts cover everything except the display part and others. As shown in the sectional view of FIG. 4, the keyboard portion of the cover member 5 is formed with a thick wall portion 5a projecting downward at a position corresponding to each input key. The thick portion 5a also serves as a key top portion.

On the lower surface of each thick portion 5a, a conductive member 5b is formed, for example, by adhering conductive rubber made of silicone rubber mixed with carbon, conductive paint, or the like by printing or the like. On the upper surface of each thick portion 5a, for example, a flat key character 5c or a key character 5d protruding upward with a step is formed. The reason why the human-powered keys 5c and 5d are formed in steps is that even when the environment in which the calculator is used is extremely poor, such as in a dimly lit environment, it can be operated by touch with the fingers, thereby preventing erroneous operations. At the same time,
This is so that parts with different functions can be clearly distinguished by visual inspection.

For example, in this embodiment, number keys from 0 to 9,
A decimal point key and an SC key (sign change key) are formed flat on the upper surface of the protrusion 5a using a method such as screen printing.

Of course, the four arithmetic operation keys and other keys, such as M
+, (memory plus equal key), M= (memory minus equal key), RM (memory recall key), CM (memory clear key), etc. are grouped into one functional category, and are formed with a step difference from other keys. You may.

By the way, a printed wiring board 7 is attached to the lower surface of the upper case 6 of the calculator, of which the cover member 5 is a part, and a key board (not shown) is installed at a position facing the conductive member 5b. A pattern has been formed. When the thick part 5a, which is the key dope part forming the key characters 5c and 5d, is pressed, the thin part 5e of the cover member 5 is elastically deformed, the conductive member 5b is lowered, and the printed wiring board 7 A key person is contacted by Kabataan, and a key person's power is carried out.

Electronic components such as an LSI 8 are fixed to the printed wiring board 7 by soldering, and display elements such as a liquid crystal display 10 are further fixed by a display holder 11 made of a thin metal plate. The output signal of LSI8 is the pressure JR type co-connector 2.
In this embodiment, a solar cell 9 is used as a power source for these electronic circuits.

The solar cell 9 is a semi-permanent power source made of silicon single crystal or amorphous material, and unlike normally used manganese, alkaline, etc. batteries, it does not need to be replaced and makes the calculator waterproof and dustproof. It is effective.

The upper surfaces of the solar cell 9 and the liquid crystal display 10 are covered with a window 13 made of a transparent synthetic resin material, making it possible to read the display on the display 10 and facilitating the introduction of external light by the solar cell.

Note that the reference numeral 14 is a bottom cover, which is formed by press working from, for example, a metal Bi plate, and is screwed with screws 15.
It is fixed to the two case 6 by '. A washer 17 made of an elastic material such as rubber is interposed between the portion fixed by the screws 15 and the bottom cover 14 to prevent water droplets from entering. Also, the bottom? , t 14 and a groove on the outer periphery of the upper case 6, a waterproof backing 16 is interposed.

Since this embodiment is configured as described below, water droplets, dust, etc. do not enter the interior, and even when used in a bad work environment, the cover member 5 made of an elastic member can be used. Since the provided key top part has a height difference depending on the key manual mechanism, it is easy to distinguish both visually and by touch, improving operability. In addition, even if dust containing oil or moisture adheres to the top surface of the cover member 5,
The areas where the key characters are protruding have the effect of being easily repelled by these liquid substances and being sufficiently resistant to stains.

In addition, as in the conventional example mentioned above, the keyboard surface is covered with a transparent elastic material, each key is separate, and all parts such as the conductive part for human power are integrated, so the structure is extremely simple. It is simplified, easy to assemble, and can reduce product costs.

Furthermore, even if the outer surface of the calculator becomes soiled with dirt or finger prints, it is completely waterproof and dustproof, so it can be washed completely and always maintain its beautiful appearance. And electricity! The top surface of the calculator is covered with a cover made of an elastic material such as rubber, so it does not slip even when used by people with long fingernails, making it easy to operate. No scratches remain even if dropped.

As is clear from the explanation below, according to the present invention, complete waterproof and dustproof effects can be obtained, the structure is simple and easy to assemble, and costs can be reduced. be.

[Brief explanation of drawings]

1 and 2 are partially enlarged vertical sectional side views illustrating a conventional key top portion, FIG. 3 is an overview perspective view showing an embodiment of the present invention, and FIG. 4 is an A-A in FIG. 3. FIG. 5... Cover member 5a... Thick part 5b... Conductive member 5c, 5d... Key manual character 6...-L case 7... Printed wiring board 9... Solar cell 10
···display

Claims (1)

[Claims] - Cover the upper surface of the computer body, which has a key cover turn on the L side and a display, etc., with an elastic cover formed with a conductive member that has input characters and contacts the key force pattern on the printed circuit board to perform key operation. An electronic desktop calculator characterized by being covered with a material.