JP3275253B2 - Keyboard switch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Generally, a vertical sliding mechanism constituted by engagement of cylindrical bodies is employed as a key board switch supporting mechanism. According to the vertical sliding mechanism, when a pressing operation force is applied to the end of the keytop, a biased operating force is applied to the vertical sliding mechanism. There is a drawback that gets worse.

In order to solve this drawback, there has been proposed a configuration 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 key top is pressed down, the key top is pressed down while maintaining a horizontal posture, and a good operational feeling is obtained.

FIG. 5 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 drawing, reference numeral 1 denotes a board constituting a keyboard. The membrane sheet 2 is laminated on the upper surface of the substrate 1.
As shown in FIG. 6, the membrane sheet 2 is formed by laminating two insulating sheets 2A and 2B at a predetermined interval by a spacer 2C, and has conductive patterns 2D and 2
E is formed. A contact is 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 brought into contact with each other to transmit a contact signal.

[0005] Reference numeral 3 denotes a housing laminated on the upper surface of the membrane sheet 2. A hole 4 (see FIG. 6) is formed in the housing 3 so as to face a contact forming portion of the membrane sheet 2, and a dome-shaped body 5 formed of an elastic material such as rubber is disposed in the hole 4. . The dome-shaped body 5 is composed of a skirt portion 5A that can be bent up and down as shown in a cross section in FIG. 6, and a push button portion 5B attached to an upper portion of the skirt portion 5A. In addition, 5C shows a notch for air release.

[0006] Reference numerals 6 and 7 denote a pair of link members. As shown in FIG. 7, each of the link members 6 and 7 has a pressing portion 6A for pressing the dome-shaped body 5 at a central portion, and is engaged with a shaft 7A formed on the other link member 7 on the outer surface. And a hole 6B to be combined. Shaft 7 of link member 7
A engages with the hole 6B formed in the link member 6, and is combined in an X shape.

The link member 6 has shafts 6C and 6D projecting outward at both ends. A shaft 7B is formed so as to extend over one end of the link member 7, and a shaft 7C protrudes outward from the other end. The shaft 7B is engaged with a rotary bearing 8A provided on the rear surface of the key top 8, the shaft 6D is engaged with a rotary bearing 3A formed on the housing 3, and these shafts 7B and 6D are rotatably supported. On the other hand, the shaft 6C is engaged with the sliding groove 8B formed on the rear 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 is engaged 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, ie, the key top 8 Is held at the top dead center position.

When the key top 8 is pressed 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 presses the contact portion of the membrane sheet 2 with the push button portion 5B to transmit a contact signal.

[0009]

Conventionally, the dome-shaped body 5 is formed as a single body, and each of the dome-shaped bodies 5 formed as a single body is adhered to the membrane sheet 2 with an adhesive.
That is, when the pantograph mechanism is employed, 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 leverage. Therefore, a downward force and a lateral force are applied to the dome-shaped body 5. As a result, the dome-shaped body 5 is easily moved in the lateral direction, so that the position is easily moved, and there is a disadvantage that the movement of the position causes variation in the feeling of operation. In order to solve this drawback, conventionally, the dome-shaped members 5 are adhered one by one to the membrane sheet 2 to fix the positions.

In order to bond the dome-shaped members 5 to the membrane sheet 2 one by one as described above, a large number of humans are required, the labor required for assembly is increased, and the cost is increased.
SUMMARY OF THE INVENTION An object of the present invention is to provide a keyboard switch which can fix the position of a dome-shaped body without any trouble and can be assembled at low cost.

[0011]

According to a first aspect of 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. The elastic sheet member is sandwiched between the membrane sheet and the housing, and the position of the dome is fixed by the elastic sheet member.

According to configuration of this, since it is not necessary to adhere to the membrane sheet by one by adhesive domed body, it is possible to save labor and labor required for assembly. Therefore, cost reduction can be expected. And a recess on the back side of the housing, proposes Kyi board switch structure configured an engaging section that engages with the pair of link members by the recess.

Further , a notch is provided in the elastic sheet member at a position facing the engaging portion which is formed in the housing and which engages with the link member constituting the pantograph mechanism and, if necessary, the membrane sheet. A key board switch is provided in which a gap is formed between the housing and the substrate, and the gap forms an engagement portion that engages with the link member.

According to the key board switch proposed in the first aspect, the engaging portion of the link member constituting the pantograph mechanism is provided on the back side of the housing or between the housing and the substrate, so that the housing and the membrane sheet can be connected to each other. Even if an elastic sheet member is inserted between them, the height of the link member can be reduced by the thickness of the housing, or by the dimension obtained by adding the thickness of the elastic sheet member and the membrane sheet to the thickness of the housing. As a result, there is an advantage that the key board can be made thinner.

[0015]

FIG. 1 shows the proposed example. FIG.
7 are denoted by the same reference numerals. In the present invention, as shown in FIG. 2, a structure in which an elastic sheet member 10 is formed integrally with the dome-shaped body 5 and this elastic sheet member 10 is sandwiched between the membrane sheet 2 and the housing 3 as shown in FIG. It is what it was. The elastic sheet member 10 and the dome-shaped body can be formed of an elastic body such as silicone rubber.

With this structure, the dome 5
Since it is not necessary to bond the individual pieces one by one, the labor required for assembling can be saved. Further, the dome-shaped body 5 is made of the elastic sheet member 1.
Since it is fixed by 0, it is arranged at the same position with respect to any key top 8 on the keyboard. As a result, the same reaction force is generated for every keytop 8,
The operational feeling can be made uniform.

[0017] proposed in Figure 3 was of Kyi board switch
Here is an example . Key over board switch a recess 11 on the rear surface of the housing 3, and constitutes an engaging portion for engagement with the link members 6 and 7 by the recess 11. The recess 11 has an introduction groove 11A communicating with the upper surface of the housing 3, and the link member 6 is formed through the introduction groove 11A.
The shafts 6D and 7C formed in the first and the seventh are inserted into the concave portion 11 so that they can be assembled in an engaged state.

According to the example shown in FIG. 3, even if the elastic sheet member 10 is interposed between the housing 3 and the membrane sheet 2, the heights of the link members 6 and 7 are equivalent to the thickness of the housing 3. Can be lower. As a result, an increase in the thickness of the elastic sheet member 10 can be eliminated, and an advantage that the increase in the overall thickness of the keyboard can be suppressed is obtained.

[0019] Figure 4 shows an embodiment of Kyi board switch proposed in claim 1 of the present invention. In this embodiment, a case is shown in which an engaging portion that engages with the lower ends of the link members 6 and 7 is constituted by a gap portion 12 formed between the housing 3 and the substrate 1. That is, a notch is formed in the elastic sheet-like body 10 and the membrane sheet 2 as required, and the gap 1 is formed between the housing 3 and the substrate 1 by the notch.
2 and the gaps 12 form the shafts 6D and 7C.
5 shows a case in which an engaging portion that engages with is formed.

As in this embodiment, the elastic sheet member 10
When a notch is formed in the membrane sheet 2 and the notch forms an air gap portion 12 that engages with the shafts 6D and 7C, the height of the link members 6 and 7 is reduced by the elastic sheet member 10 and the membrane sheet. 2 and the thickness of the housing 3 can be reduced. Therefore, there is an advantage that the entire thickness of the key board can be reduced.

[0021]

As described above, according to the present invention, since the dome-shaped member 5 is integrally formed by the elastic sheet member 10, the dome-shaped members 5 are bonded one by one to the contact forming portions of the membrane sheet 2 one by one. There is no need to perform the mounting work. Therefore, the labor required for assembly can be saved.

Further, according to the present invention, the position of the dome-shaped body 5 can be uniformly arranged with the accuracy of the molding die, so that the variation in the position with respect to each keytop 8 can be suppressed. Therefore, the reaction force to each keytop 8 can be made uniform, and the advantage that the feeling of operation can be made uniform is also obtained. Further, according to the embodiment shown in FIGS. 3 and 4, the key board can be reduced in thickness. Therefore, it is suitable to be applied to, for example, a portable electronic device.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first example of a proposed keyboard switch.

FIG. 2 is a side view for explaining the structure of the main part of FIG . 1 ;

FIG. 3 is a sectional view showing a second example of the proposed keyboard switch.

FIG. 4 is a sectional view showing an embodiment of the keyboard switch proposed in claim 1 of the present invention.

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

FIG. 6 is an enlarged cross-sectional view showing the structure of a conventional dome-shaped body and its mounted state.

FIG. 7 is a perspective view for explaining an example of a link member constituting the pantograph mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Membrane sheet 3 Housing 4 Hole 5 Dome body 6, 7 Link member 8 Key top 10 Elastic sheet member 11 Concave part 12 Void part

Claims (1)

(57) [Claims] An engaging portion mounted on a membrane sheet for exposing a contact portion formed on the membrane sheet, and an engaging portion for engaging a link member for supporting a keytop on a periphery of the hole. A housing formed of an insulating resin material, and an elastic member attached to the membrane sheet exposed at the hole portion, and for turning on and off a contact formed on the membrane sheet by pressing a keytop. One end is engaged with a dome-shaped body formed of a material, and an engagement portion formed on the housing,
A pair of link members rotatably connected to each other at an intermediate portion, the other end engaging with the back surface of the key top, and supported by a pantograph mechanism such that the key top moves substantially parallel to the surface of the housing. , the dome-shaped body by integrally molded with the elastic sheet member, the elastic sheet member is laminated between the membrane sheet and the housing, a concave portion is provided on the rear surface of the housing, to the recess and facing
A notch is provided at the position of the elastic sheet member.
Between the housing and the membrane sheet
A gap portion is formed, and the link portion is formed by the gap portion.
A keyboard switch characterized in that a material engaging portion is formed .