JPH0443932Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a flat type keyboard switch used as an input device for various electrical equipment, and particularly relates to a keyboard switch having a two-step operation function. .

[Conventional technology and its problems]

A conventional two-stage operation switch is shown in FIG. This switch is equipped with two types of movable contacts 2 and 3 of different heights on a dome-shaped spring member 1 made of rubber material, and a printed circuit board 4 has fixed contacts 5 and 6 for the first stage and fixed contacts 5 and 6 for the second stage. This is a configuration in which fixed contacts 7 and 8 are attached.

When the push button 9 is pushed down one step, the movable contact 2 contacts the fixed contacts 5 and 6, and when the push button 9 is pushed down further, the movable contact 3 contacts the fixed contacts 7 and 8.
It is designed to operate in two stages by contacting the

However, with this configuration, it is difficult to shorten the stroke, and it is also difficult to reduce the thickness.

[Purpose of invention]

The object of the present invention is to provide a flat type keyboard switch that has a small stroke, has a two-step operation function, and can provide a click feeling during the second step operation.

[Means for solving problems]

The present invention includes a printed circuit board provided with a first fixed contact, and a diameter A at a position corresponding to the fixed contact.
a first spacer having a through hole of diameter B, a first insulating sheet having a second fixed contact and a movable contact opposite to the first fixed contact on the upper and lower surfaces, respectively, and a through hole having a diameter of B. a second spacer;
A second insulating sheet provided with a second movable contact facing the second fixed contact and a substantially dome-shaped spring having a diameter of C are sequentially laminated, and the
It is characterized by a configuration in which the relationship between each dimension of ABC is A<C<B.

The first stage switch circuit is turned on when the spring is lightly pushed down via the top sheet, and when the spring is reversed by further pushing down, the second stage switch circuit is turned on.

〔Example〕

FIG. 1 shows an embodiment of the present invention.
A flexible printed circuit board 10 having a fixed contact 11 made of a conductor pattern, a spacer 20 having a through hole 21 with a diameter A, a movable contact 31 facing the fixed contact 11 on the lower surface, and a fixed contact 32 on the upper surface. An insulating sheet 30, a spacer 40 having a through hole 41 with a diameter B, a flexible insulating sheet 50 having a movable contact 52 opposite to the fixed contact 32 on the lower surface, a through hole having a smaller diameter than the through hole 41. A spacer 60 having 61 and a flexible top sheet 70 are sequentially laminated and integrated by adhesive or other means.

Then, a dome-shaped spring 80 made of metal or the like is installed in the through hole 61, and the diameter A of the through hole 21, the diameter B of the through hole 41, and the spring 8
The diameter C of the dome portion of 0 is set in the relationship A<C<B. Further, the strength of the dome-shaped spring 80 and the degree of flexibility of the seat 50 are such that when the spring 80 is pressed down, the strength of the spring 80 is
The movable contact 52 switches to the fixed contact 3 before the switch is reversed.
2 was selected to touch.

The keyboard switch according to the present invention constructed as described above operates as follows.

First, the spring 80 is placed on top of the top sheet 70.
Press down lightly to release the sheet 50 as shown in Figure 2.
is bent and the movable contact 52 and fixed contact 32 come into contact,
The first stage switch circuit turns on. Then,
When the top sheet 70 is further pushed down, the third
As shown in the figure, the spring 80 is reversed and the seat 30 is
Push down to bring the movable contact 31 and fixed contact 11 into contact. As a result, the second stage switch circuit is also turned on.

Thereafter, when the force pressing the top sheet 70 is released, the spring 80 and the sheets 30 and 50 return to the state shown in FIG. 1 by their own elasticity.

FIG. 4 shows another embodiment of the keyboard switch according to the present invention. In this example, the spacers 20 and 40 are formed by point-like protrusions made of flexible plastic that are printed on the printed circuit board 10 and the sheet 30, respectively. Further, the dome-shaped spring 80 is obtained by press-molding a single elastic plate, and has a structure that also serves as a top sheet.

[Effect of idea]

According to the present invention, it is possible to obtain a two-stage keyboard switch that has a small stroke, can be configured to be extremely thin, and also produces a click feeling when the second stage is activated.

[Brief explanation of drawings]

FIG. 1 is a front sectional view showing one embodiment of the keyboard switch according to the present invention, FIGS. 2 and 3 are front sectional views of the switch in its operating state, and FIG. 4 is a front sectional view showing another embodiment. , FIG. 5 is a front sectional view showing an example of a conventional two-stage operation type switch. 10... Printed circuit board, 11, 32... Fixed contact, 20, 40... Spacer, 21, 41... Through hole, 30, 50... Sheet, 31, 52... Movable contact, 80... Spring.

Claims (1)

[Scope of utility model registration request] a printed circuit board provided with a first fixed contact;
a first spacer having a through hole with a diameter A at a position corresponding to the fixed contact, and a first insulator provided with a second fixed contact and a movable contact facing the first fixed contact on the upper and lower surfaces, respectively. A sheet, a second spacer having a through hole with a diameter B, a second insulating sheet provided with a second movable contact facing the second fixed contact, and a substantially dome-shaped spring with a diameter C are sequentially installed. A keyboard switch characterized in that the keyboard switch is laminated and the dimensional relationship of the ABCs is A<C<B.