JP2001118458A - Dust-proof structure for membrane keyboard - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dust-proof structure for a membrane keyboard, which has an optimized air drainage passage and air retention space that are commonly formed in all of key switch electrodes. SOLUTION: A keyboard includes a plurality of switch spaces formed by a spacer layer of an upper sheet and a spacer layer of a lower sheet and receiving the electrodes disposed opposite at given intervals; and air retention spacers formed by the spacer layer of the upper sheet and the spacer layer of the lower sheet every switch spaces. Also, at one of the spacer layers, there is formed an air drainage passage serving to connect the switch spaces to the air retention space. At the other space layer, there is formed an air drainage passage communicating with the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dustproof structure of a membrane keyboard used in, for example, a personal computer and the like, and more particularly to a dustproof structure in which a key switch portion has an improved air vent structure.

[0002]

2. Description of the Related Art For example, there is one disclosed in Japanese Utility Model Application No. 63-156000. As shown in FIGS. 5 to 9, the dustproof structure of the conventional membrane keyboard is formed by bonding an upper sheet 20, a spacer 21, a lower sheet 22, an adhesive sheet 23, and a bracket 24. A plurality of electrodes 25 and 26 are printed on the lower surface of the upper sheet 20 and the upper surface of the lower sheet 22 so as to face each other.
In the spacer 21, a switch space 27 is formed at a position corresponding to the electrodes 25 and 26. In the switch space 27, the electrodes 25 and 26 face each other at a predetermined interval. Make up.

The spacer 21, the upper sheet 20, and the lower sheet 22 are bonded to corresponding surfaces of the two sheets 20, 22 by using adhesive layers 28, 29 formed by printing or the like.
The adhesive layers 28 and 29 are formed on the outer peripheral portions of the surfaces of the sheets 20 and 22 in the form of an elongated strip, and a part of the strip-shaped adhesive layers 28 and 29 is provided with a slight gap. The air vent passages 30 and 31 are formed adjacent to each other. Air vent passages 30, 31
In the inner surfaces of the two sheets 20 and 22, a portion is cut out to form passage openings 30 a and 31 a, and a gap formed between the joining surfaces of the two sheets 20 and 22 and the spacer 21 and a switch space 27 are formed. And the outside of the keyboard KB via the air vent passages 30 and 31.

Further, in the middle of the air vent passages 30, 31, pockets 30b,
An air space 21a is formed at a position where the spacer 31b is opposed, and also at a position where the spacer 21 is opposed. The air space 21a can be formed at the same time when the switch space 27 is formed in the spacer 21 by molding or punching. The pockets 30b and 31b and the air space 21a form an air reservoir space 32 as shown in FIG. 7 when the spacer 21 is bonded to the upper sheet 20 and the lower sheet 22.

In such a configuration, the keyboard KB is assembled by bonding the upper sheet 20, the spacer 21, the lower sheet 22, the adhesive sheet 23, and the bracket 24 as described above.

When the electrode 25 of the key switch is pressed as shown in FIG. 8, the air in the switch space 27 of the spacer 21 is released from the peripheral gap through the passage openings 30a, 3a.
1a through the air vent passages 30, 31 and then through the air reservoir space 32 on the way to the membrane keyboard KB
It is discharged outside.

Next, as shown in FIG. 9, when the above-mentioned pressing of the key switch is released, the switch space 27 has a negative pressure, so that external air flows into the switch space 27 through the air vent passages 30 and 31. Try to flow in. However, since the air vent passages 30 and 31 are narrow, the flow rate of the external air is suppressed to be small, and the air storage space 32 is provided, so that the flow rate of the inflowing air is further reduced in the air storage space 32. That is, since a stagnation action is caused, most of the dust D mixed in the external air is settled in the air accumulation space 32. If dust that does not settle remains in the air accumulation space 32, the air vent passages 30, 31 are further removed.
Flows through the passage openings 30a and 31a to the switch space 27, but adheres or sinks to the surroundings at the passage walls of the air vent passages 30 and 31 or in the gap around the switch space 27 in the flow process. Like that.

[0008]

However, since the air vent passage and the air reservoir space of the dustproof structure of the conventional membrane keyboard KB are provided in common with all the key switch electrodes of the membrane keyboard KB, the arrangement of the keys is reduced. Each time it is different, it is necessary to consider the routing of the air vent passage and the optimal arrangement of the air reservoir each time. In addition, the arrangement intervals of the key switches tend to be small, but in the related art, it is necessary to pass an air vent passage between the key switches, so that the demand for miniaturization cannot be satisfied. There was a problem.

[0009]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides an upper sheet on which a plurality of switch electrodes and a spacer layer are formed, and a lower sheet on which an electrode and a spacer layer opposed to the electrodes are formed. In a membrane keyboard comprising a sheet, a plurality of switch spaces formed by the spacer layer of the upper sheet and the spacer layer of the lower sheet and accommodating the electrodes facing each other at a predetermined interval, the spacer layer of the upper sheet, An air reservoir space formed by the spacer layer of the lower sheet is provided for each switch space, and an air vent passage connecting the switch space and the air reservoir space is formed in one spacer layer,
An air vent passage communicating with the outside is provided in the other spacer layer.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded perspective view of a main part of a membrane keyboard according to an embodiment. FIG. 2 is an enlarged plan view of a main part of the membrane keyboard according to the embodiment. FIG. 3 is a sectional view taken along line BB of FIG. 2, and FIG. 4 is a sectional view taken along line AA of FIG.

In FIG. 1, a membrane keyboard (hereinafter referred to as "keyboard") KB is formed by bonding an upper sheet 1, a lower sheet 2 and a bracket 3 together.

A plurality of upper electrodes 4 are provided on the lower surface of the upper sheet 1.
And the upper spacer 6 are formed. An upper switch space 8 is formed in the upper spacer 6 of the upper sheet 1 at a position corresponding to the upper electrode 4.
Are communicated with the upper air reservoir space 10 by the upper air vent passage 12. A plurality of lower electrodes 5 and lower spacers 7 are formed on the upper surface of the lower sheet 2. Lower sheet 2
A lower switch space 9 is formed at a position corresponding to the lower electrode 5 in the spacer 7 of the lower switch space 9.
Communicates with the lower air reservoir space 11 through the lower air vent passage 13.

As shown in FIGS. 2 to 4, in the assembled keyboard KB, a switch space 15 is formed by upper and lower switch spaces 8 and 9, and the electrodes 4 and 5 oppose at a predetermined interval. This constitutes a key switch.

An air storage space 16 is formed by the upper and lower air storage spaces 10 and 11, and the switch space 15 and the air storage space 16 are communicated by an upper air vent passage 12 provided in the upper spacer 6. In addition, air pool space 1
6 is a lower air vent passage 13 provided with the lower spacer 7.
To the outside 17 of the keyboard KB.

In such a configuration, when the electrode 5 side of the key switch is pressed, the air in the switch space 15
The air is discharged to the outside of the keyboard KB 17 through the upper air vent passage 12, the middle air reservoir space 16, and the lower air vent passage 13. Next, when the key switch is released,
Since the switch space 15 has a negative pressure, the air in the outside 17 tries to flow into the switch space 15 through the lower air vent passage 13, the air reservoir space 16, and the upper air vent passage 12. However, the upper and lower air vent passages 12, 13
Are provided narrowly and alternately above and below, so that the flow velocity of the external air can be kept low, and the flow rate of the inflowing air is further reduced by the air reservoir space 16. That is, since a stagnation effect is caused, the dust D
Mostly, the synergistic effect of the air storage space 16 and the air vent passages 12 and 13 provided alternately up and down improves the efficiency of the sedimentation in the air storage space 16.

[0016]

As described above, according to the present invention, since the air vent passage and the air reservoir space of the dustproof structure are provided for each key switch electrode, even if the arrangement of the key switch electrodes differs. It is not necessary to examine the layout of the air vent passage and the optimal arrangement of the air reservoir each time. Further, since a dustproof structure can be constructed around the key switch electrodes, the arrangement interval of the key switch electrodes can be reduced and the size can be reduced. Further, a synergistic effect of the air accumulation space and the air vent passages provided alternately in the upper and lower directions improves the efficiency of sedimentation in the air accumulation space.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a main part of a keyboard according to an embodiment of the present invention.

FIG. 2 is an enlarged plan view of a main part in an assembled state according to the embodiment of the present invention.

FIG. 3 is a sectional view taken along line BB of FIG. 2;

FIG. 4 is a sectional view taken along line AA of FIG. 2;

FIG. 5 is an exploded perspective view of a conventional keyboard.

FIG. 6 is an assembled plan view of a conventional keyboard.

FIG. 7 is an enlarged sectional view of a main part of a conventional keyboard.

FIG. 8 is an enlarged cross-sectional view of a key switch section of a conventional keyboard.

FIG. 9 is an enlarged cross-sectional view of a key switch portion of a conventional keyboard.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upper sheet 2 Lower sheet 3 Bracket 4 Upper electrode 5 Lower electrode 6 Upper spacer 7 Lower spacer 8 Upper switch space 9 Lower switch space 10 Upper air storage space 11 Lower air storage space 12 Upper air vent passage 13 Lower air vent passage 15 Switch Space 16 Air pocket space 17 External

Claims (1)

[Claims] 1. A membrane keyboard comprising: an upper sheet on which a plurality of switch electrodes and a spacer layer are formed; and a lower sheet on which electrodes and a spacer layer opposed to the electrodes are formed. A plurality of switch spaces formed by a spacer layer of a lower sheet and accommodating the electrodes facing each other at a predetermined interval; and an air reservoir space formed by a spacer layer of the upper sheet and a spacer layer of the lower sheet. An air vent passage connecting the switch space and the air reservoir space is formed in one spacer layer, and an air vent passage communicating with the outside is provided in the other spacer layer. Dustproof structure of keyboard.