JPH0963397A - Keyboard switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily incorporate a domed body, and also improve reliability of a contact point part formed on a membrane sheet in a keyboard switch. SOLUTION: A domed body 5 is integrally molded in a condition of being connected by an elastic sheet member 10, and the elastic sheet member is sandwiched between a membrane sheet 2 and a housing 3, and a projecting strip frame 10A is formed on the elastic sheet member so as to surround a key hole 4. A recessed groove 3C formed on the reverse of the housing 3 is engaged with this projecting strip frame 10A, and a dustproof structure is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a keyboard switch that can be used in various devices such as a personal computer or a word processor.

[0002]

2. Description of the Related Art Generally, as a support mechanism of a keyboard switch, a vertical sliding mechanism constituted by engagement of cylinders is adopted. According to the vertical sliding mechanism, when a pressing operation force is applied to the end of the key top, the vertical sliding mechanism is applied with an eccentric operating force, which causes sliding and hinders smooth sliding, resulting in a feeling of operation. It has the drawback of getting worse.

In order to solve this drawback, there has been proposed a structure in which a key top is supported by a pantograph mechanism as described in, for example, "US Pat. No. 4,433,225". By adopting a structure in which the key top is supported by the pantograph mechanism, even if the end of the key top is pressed, the key top is pressed while maintaining a horizontal posture, and a comfortable feeling of operation can be obtained.

FIG. 4 shows an example of a key board switch having a structure in which a key top is moved up and down by a pantograph mechanism. In the figure, reference numeral 1 indicates a substrate which constitutes a key board. The membrane sheet 2 is laminated on the upper surface of the substrate 1.
As shown in FIG. 5, in the membrane sheet 2, two insulating sheets 2A and 2B are laminated with a spacer 2C at a predetermined interval, and conductive patterns 2D and 2E are formed on the opposing surfaces. Contact points are formed by the conductive patterns 2D and 2E, and by pressing the upper insulating sheet 2A from above, the conductive patterns 2D and 2E are contacted and a contact signal is transmitted.

Reference numeral 3 denotes a housing laminated on the upper surface of the membrane sheet 2. A key hole 4 (see FIG. 5) is formed in the housing 3 so as to face the contact formation portion of the membrane sheet 2, and a dome-shaped body 5 formed of an elastic material such as rubber is formed in the key hole 4 portion. Deploy. The dome-shaped body 5 is composed of a skirt portion 5A that can be bent in the vertical direction as shown in the cross section in FIG. 5, and a push button portion 5B attached to the upper portion of the skirt portion 5A. In addition,
5C shows a notch for venting air. Positioning pins 1A for positioning the membrane sheet 2 and the housing 3 are provided on the substrate 1 in a protruding manner. The positioning pin 1A is engaged with the positioning hole 2D formed in the membrane sheet 2,
The positional relationship between the membrane sheet 2 and the substrate 1 is determined, and a recess hole for engaging the pin 1A is formed on the back surface of the housing 3, and the pin 1A is engaged in this recess hole to form the membrane sheet 2 and the housing. 3 defines the positional relationship with

Reference numerals 6 and 7 denote a pair of link members. As shown in FIG. 6, the link members 6 and 7 have a pressing portion 6A that presses the dome-shaped body 5 in the central portion thereof, and the link member 6 engages with a shaft 7A formed on the other link member 7 on the outer surface. And a hole 6B for mating. Link member 7 shaft 7
A engages with a hole 6B formed in the link member 6 and is assembled in an X shape.

The link member 6 is provided with shafts 6C and 6D projecting outward at both ends thereof. The link member 7 is formed with a shaft 7B extending over one end side, and a shaft 7C protruding outwardly on the other end side. The shaft 7B is engaged with a rotary bearing 8A provided on the back surface of the key top 8, the shaft 6D is engaged with a rotary bearing 3A formed in the housing 3, and the shafts 7B and 6D are rotatably supported. On the other hand, the shaft 6C is engaged with the sliding groove 8B formed on the back side of the key top 8, and the shaft 7C is engaged with the sliding groove 3B formed on the housing 3. In this state, the pressing portion 6A formed on the link member 6 engages with the top surface of the push button portion 5B of the dome-shaped body 5, and the link members 6 and 7 are raised by the elasticity of the dome-shaped body 5, that is, the key top 8 Is held at the top dead center position.

When the key top 8 is pushed down, the link members 6 and 7 are displaced in a direction approaching the surface of the housing 3. At this time, the pressing portion 6A formed on the link member 6 crushes the dome-shaped body 5, and the push button portion 5B presses the contact portion of the membrane sheet 2 to emit a contact signal.

[0009]

Conventionally, the dome-shaped body 5 is formed as a single body, and each dome-shaped body 5 formed as a single body is adhered and attached to the membrane sheet 2 with an adhesive.
That is, when the pantograph mechanism is adopted, the dome-shaped body 5 is pressed by the pressing portion 6A formed on the link member 6. The pressing portion 6A moves in an arc by a lever movement. Therefore, a downward force and a lateral force are applied to the dome-shaped body 5. As a result, since the dome-shaped body 5 receives a lateral force, the position is likely to move, and there is a drawback that the feeling of operation varies due to the movement of the position. In order to solve this drawback, conventionally, the dome-shaped bodies 5 are bonded to the membrane sheet 2 one by one, and the positions are fixed. As described above, a lot of manpower is required to bond the dome-shaped bodies 5 one by one to the membrane sheet 2, and it takes a lot of labor for assembling, and there is a drawback that the cost becomes high.

Further, conventionally, as described with reference to FIG.
The positioning pin 1A is provided in a protruding manner on this position, and the positioning hole 1D formed in the membrane sheet 2 is engaged with this positioning pin 1A to position the membrane sheet 2. In the membrane sheet 2, the insulating sheets 2A and 2B and the spacer 2C are adhered to each other at their peripheral portions with a double-sided adhesive tape or the like, but at the contact forming portion, the insulating sheet 2A and the spacer 2C are attached.
The spacer 2C and the insulating sheet 2B are not adhered to each other.

Therefore, when dust, dust, or moisture enters between the housing 3 and the membrane sheet 2 through the key hole 4 formed in the housing 3, the dust, dust, or moisture is used for positioning. Insulation sheet 2A at the hole 2D
And the spacer 2C and between the insulating sheet 2B and the spacer 2C
There is a risk that it will enter the gaps and eventually penetrate into the portions where the conductive patterns 2D and 2E are formed, resulting in poor contact.

The object of the present invention is to simplify the work of attaching the dome-shaped body 5 and to prevent dust and the like from entering the membrane sheet 2. It is intended to provide a key board switch having a structure.

[0013]

According to the present invention, in a key board switch having a structure in which a key top is moved up and down by a pantograph mechanism, a dome-shaped body for giving a reaction force to the key top is integrally formed with an elastic sheet member to form an elastic sheet. The member is sandwiched between the membrane sheet and the housing, and the elastic sheet member is used to fix the position of the dome-shaped member, and the elastic sheet member is surrounded by the key hole and is formed by the ridge. A ridge frame is provided, and a concave groove that engages with the ridge frame is further formed on the back surface of the housing, and a dust-proof structure is formed by the engagement of the ridge frame formed on the elastic sheet member and the groove formed on the housing. It is characterized by.

According to the structure proposed by the present invention, it is not necessary to bond the dome-shaped bodies to the membrane sheet one by one with an adhesive, so that the labor required for assembly can be saved. Therefore, cost reduction can be expected. Further, since the dust-proof structure is formed by the engagement of the protrusion frame surrounding the key hole and the concave groove formed in the elastic sheet member, a key board switch that does not enter dust and operates stably for a long time is provided. be able to.

[0015]

FIG. 1 shows an embodiment of the present invention. Portions corresponding to those in FIGS. 4 to 6 are designated by the same reference numerals. In this invention, as shown in FIG. 2, an elastic sheet member 10 is formed integrally with the dome-shaped body 5, and the elastic sheet member 10 is sandwiched between the membrane sheet 2 and the housing 3 as shown in FIG. It is what The elastic sheet member 10 and the dome-shaped body can be formed of an elastic body such as silicon rubber.

Further, according to the present invention, a projecting frame 10A surrounding the key hole 4 formed in the housing 3 and projecting from the elastic sheet member 10 is provided, and the projecting frame 10A and the groove 3C formed on the back surface of the housing 3 are provided. And are engaged to form a dustproof structure. FIG. 3 shows a state of the ridge frame 10A formed on the elastic sheet member 10 and the dome-shaped body 5. Ridge frame 1
0A surrounds the dome-shaped body 5 and is formed integrally with the elastic sheet member 10. The ridge frame 10A surrounds the formation position of the dome-shaped body 5 and is formed outside the formation position of the engaging portions 3A and 3B formed in the housing 3, as shown in FIG.

Therefore, the concave groove 3C formed on the back side of the housing 3 is also selected outside the positions where the engaging portions 3A and 3B are formed, and at a position where the positioning pin 1A is not included in the protruding frame 10A. The ridge frame 10A protruding from the elastic sheet member 10 is engaged with the groove 3C. With the structure of the present invention, it is not necessary to bond the dome-shaped bodies 5 one by one, so that the labor required for assembly can be saved. Further, since the dome-shaped body 5 is fixed by the elastic sheet member 10, it is arranged at the same position with respect to any key top 8 on the key board. As a result, the same reaction force is generated for any key top 8, and the operation feeling can be made uniform.

A ridge frame 10A is formed on the elastic sheet member 10 so as to surround the key hole 4, and the ridge frame 10 is formed.
Since the concave groove 3C formed in the housing 3 is engaged with A, even if dust or the like enters from the portion of the key hole 4, the dust is prevented from entering at the protruding frame 10A and the concave groove 3C and is used for positioning. The position of pin 1A is never reached. As a result, dust and the like form the insulation sheets 2A and 2B that form the membrane sheet 2 through the positioning holes 2D formed in the membrane sheet 2.
And the spacer 2C do not enter. Therefore, dust and the like do not enter the formation position of the contact portion of the membrane sheet 2, and it is possible to provide a key board switch that operates stably for a long period of time.

[0019]

As described above, according to the present invention, since the dome-shaped bodies 5 are integrally formed by the elastic sheet member 10, the work of attaching the dome-shaped bodies 5 one by one to the contact portions of the membrane sheet 2 can be performed. There is an advantage that it is not necessary to carry out and the assembling can be performed easily. Further, since the ridge frame 10A is formed on the elastic sheet member 10 and the groove 3C formed on the back surface of the housing 3 is engaged with the ridge frame 10A, dust or dust is discharged from the key hole 4 formed in the housing 3. , Moisture, etc. are elastic sheet member 10 and housing 3
Even if it intrudes into the gap between the ridge and the groove, this dust, dust, moisture or the like is prevented from further invading at the position of the ridge frame 10A and the concave groove 3C formed in the housing 3. Therefore, each sheet 2 that constitutes the membrane sheet 2 through the positioning holes 2D
It is possible to provide a key board switch that does not enter between A, 2B, and 2C and operates stably over a long period of time.

[Brief description of drawings]

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

FIG. 2 is a side view for explaining a dome-shaped body and an elastic sheet member used in the embodiment shown in FIG.

FIG. 3 is a perspective view for explaining a configuration of a main part of the present invention.

FIG. 4 is a cross-sectional view for explaining a conventional technique.

FIG. 5 is a cross-sectional view for explaining a conventional technique.

6 is a perspective view for explaining an example of the link member used in the embodiment shown in FIG.

[Explanation of symbols]

 1 Substrate 1A Positioning Pin 2 Membrane Sheet 2D Positioning Hole 3 Housing 3C Recessed Groove 4 Key Hole 5 Dome 6,7 Link Member 8 Keytop 10 Elastic Sheet Member 10A Projection Frame

Claims (1)

[Claims] 1. A member which is laminated on a membrane sheet and which engages with a key hole for exposing a contact portion formed on the membrane sheet and a link member for supporting the key top on the periphery of the key hole. It is attached to the housing made of insulating resin material and the membrane sheet exposed at the key hole, and the contact formed on the membrane sheet is turned on / off by pressing the key top. A dome-shaped body formed of an elastic material to be operated, and one end of which engages with an engaging portion formed on the housing,
A pair of link members that are rotatably connected to each other at an intermediate portion and that have the other ends supported by a pantograph mechanism so as to engage the back surface of the key top and move the key top substantially parallel to the surface of the housing. In the key board switch configured as described above, the dome-shaped body is integrally molded with the elastic sheet member, the elastic sheet member is laminated between the membrane sheet and the housing, and the key hole formed in the housing is surrounded. A key board switch, characterized in that a projection frame projecting from the elastic sheet member is provided on the housing, and the projection frame is engaged with a groove formed on the back surface of the housing to form a dustproof structure.