JPH0235137Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement of a thin film switch (membrane switch) applied to, for example, a keyboard.

FIG. 1 shows a known thin film switch. A spacer member 12, a flexible printed circuit board 13, and a top sheet 14 are laminated in this order on the printed circuit board 11. The spacer member 12 is provided with a through hole 15 corresponding to the key area E printed on the top sheet 14, and the printed circuit boards 11 and 13 located in the through hole 15 are provided with opposing fixed contacts. The piece 16 and the movable contact piece 17 are formed by printing. When the key area E of the top sheet 14 is pressed down, the printed circuit board 13 is bent and the movable contact piece comes into contact with the fixed contact piece 16. When the pressing force is released, the elastic force of the printed circuit board 13 causes the printed circuit board 13 to bend as shown in FIG. It is designed to restore the condition.

By the way, in this type of switch, the shape of the key area E can be changed in various ways. In the case of the above configuration, when the key area E becomes larger, the through hole 15 of the spacer member 12 also becomes larger. Therefore, the flexible printed circuit board 13 bends downward and the movable contact piece 17
It becomes difficult to maintain a sufficient insulation distance between the contact piece 16 and the fixed contact piece 16. This is difficult to deal with because the printed circuit board 13 will be further bent when the temperature of the environment in which the switch is used rises. Therefore, in a switch with this type of structure, it is desirable to make the size of the through hole 15 smaller than the key area E, but in this case, the switch cannot be operated unless the center of the through hole 15 is pressed accurately. As a result, a problem arises in that operability deteriorates.

Therefore, thin film switches shown in FIGS. 2 and 3 have been developed. The switch shown in FIG. 2 is a key switch 2 consisting of a push button switch on a printed circuit board 21.
2 is provided, and the operating section 23 of this key switch 22
The mover 2 provided in the through hole 25 of the panel 24
The panel 24 is provided with a top sheet 28. With such a configuration, the insulation distance will not change depending on the environmental temperature. but,
When the end of key area E is operated, mover 26
The inclination of the key switch becomes large, which may cause malfunctions due to friction with the inner surface of the through hole 25, or malfunctions such as the key switch 22 not turning on even if a specified stroke or a specified operating force is applied.

Figure 3 shows the configuration when a large key area _EW is required. In this case, one mover 30 is provided with two protrusions 31 and 32, and these protrusions 31 and 32 allow the operation parts 35 and 3 of the key switches 33 and 34 to
The key switches 33 and 34 are connected in parallel, for example. Also,
The same parts in the figure as in FIG. 2 are given the same reference numerals. With such a configuration, switch output can be obtained by operating any part of the key area _EW , but depending on the operating state, the key switch 33, 3
If the switches 33 and 4 do not operate in the same state, and the on-time intervals of these switches 33 and 34 are separated in time, there is a problem that the chattering prevention circuit also does not work.

This idea was made based on the above circumstances, and its purpose is to be able to obtain reliable operation no matter which part of the key area is operated, and to easily adapt it to various key area shapes. The aim is to provide a thin film switch that can handle the

An embodiment of this invention will be described below with reference to the drawings.

FIG. 4 shows an embodiment corresponding to the switch shown in FIG. 1, and the same parts as in FIG. 1 are given the same reference numerals, and only the different parts will be explained. In FIG. 4, a spacer member 41 as a holder is provided on the flexible printed circuit board 13, and a top sheet 14 is provided on this spacer member 41.
The spacer member 41 is provided with a through hole 42 as a storage portion of a size corresponding to the key area E,
An actuating member 43 is provided inside this through hole 42 . This actuating member 43 is made of an elastic metal plate, and as shown in FIG. 5, both ends thereof are bent so as to be parallel to each other to form support parts 44 and 45. In addition, the support portions 44, 4 are provided in the central portion.
A protrusion 46 that protrudes from 5 is formed. still,
The through hole 15 of the spacer member 12 is connected to the spacer member 41.
The protrusion 46 of the actuating member 43 is in contact with the flexible printed circuit board 13 located at the center of the through hole 42 .

In the above configuration, when the central part of the key area E of the top sheet 14 is pressed, the flexible printed circuit board 13 is bent by the protrusion 46 of the actuating member 43, and the movable contact piece 17 is moved from the fixed contact piece. 1
6 is contacted. Also, when the pressing force is released,
The state shown in FIG. 4 is restored.

Furthermore, when the key area E is pressed, for example, on the support portion 44 side end, the actuating member 43 moves to the protrusion 46.
The actuating member 43 is rotated in the direction of arrow B shown in FIG. be moved. Then, the flexible printed circuit board 13 is bent by the protrusion 48 as described above, and the movable contact piece 17 comes into contact with the fixed contact piece 16.

According to the embodiment described above, the movable contact piece 17 is operated by the actuating member 43 having support parts 44 and 45 at both ends. Therefore, even when the end of the key area E is operated, the actuating member 4
3 rotates around the support parts 44 and 45 to operate the movable contact piece 17, so it is possible to obtain a stable contact operation no matter which part of the key area E is pressed.

Further, since the size of the through hole 15 of the spacer member 12 can be made smaller than the key area E, it is possible to suppress the bending of the flexible printed circuit board 13 due to environmental conditions.

Furthermore, since the size of the through hole 15 is less affected by the size of the key area E, it is possible to easily accommodate various key area shapes.

Next, another embodiment of this invention will be described.

FIG. 6 shows this invention applied to the switch shown in FIG. 2, and the same parts as in FIG. 2 are given the same reference numerals, and only the different parts will be explained. In FIG. 6, a panel 61 as a holder on which the top sheet 28 is provided is provided with a recess 62 as a storage portion corresponding to the key area E, and a through hole 63 is provided in the center of this recess 62. ing. The operating portion 23 of the key switch 22 is inserted through the through hole 63. Further, an actuating member 64 is provided inside the recess 62 . This actuating member 64 has support portions 65 and 6 at both ends similarly to the actuating member 43.
6 is formed, and the central portion is provided above the operating portion 23 of the key switch 22.

Even with such a configuration, it is possible to obtain good operational performance similar to the above embodiment.

FIG. 7 shows an application of this invention to the switch shown in FIG. 3. The same parts as in FIG. 3 are given the same reference numerals, and only the different parts will be explained. In FIG. 7, a panel 71 as a holder has a recess 72 as a storage section corresponding to the key area E _W.
A through hole 73 is provided at the bottom of this recess 72.
74 are provided. The operating portions 35 and 36 of the key switches 33 and 34 are inserted into the through holes 73 and 74, respectively. Furthermore, an actuating member 75 is provided inside the recess 72 . This operating member 75
Like the operating members 43 and 64, supporting parts 76 and 7 are formed at both ends, and the central part is connected to the key switch 3.
3, 34 are provided on the operating sections 35, 36.

Even with such a configuration, good operational performance can be obtained. Further, since the actuating member 75 has elasticity, it is possible to suppress the occurrence of two-stage operation as in the conventional case.

Note that the material and shape of the actuating member are not limited to those in the embodiment.

It goes without saying that various other modifications can be made without departing from the gist of the invention.

As detailed above, this invention provides a thin film switch that can provide reliable operation no matter which part of the key area is operated, and that can easily accommodate various key area shapes. can.

[Brief explanation of drawings]

1 to 3 are side sectional views showing different conventional thin film switches, FIG. 4 is a side sectional view showing an embodiment of the thin film switch according to this invention, and FIG. 5 is the main part of FIG. 4. Perspective view taken out, No. 6
7 are side sectional views showing other embodiments of this invention. 16... fixed contact piece, 17... movable contact piece, 22,
33, 34...key switch, 23, 35, 36
...Operation unit, 14, 28...Top sheet, E,
E _W ...Key area, 41,61,71...Panel, 42...Through hole, 62,72...Recess, 43,
64, 75... Operating member, 44, 45, 65, 6
6, 76, 77...Support part.

Claims (1)

[Scope of utility model registration request] In a thin film switch that drives a switch movable part to change the switch state by pressing a key area formed on a top sheet, a holder having a bottomed storage part corresponding to the key area and the switch movable part; , provided inside the storage section, with an intermediate portion abutting the switch movable section and being rotatable relative to the movable section, and having both ends capable of abutting against the bottom of the storage section; 1. A thin film switch comprising: an actuating member having a support portion serving as a rotation fulcrum.