JP2000294070A - Key switch - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To improve the degree of freedom of wiring and reduce noise. SOLUTION: A switching means 8 operated by operating an operated part 2b, a piezoelectric element 6 which generates vibration by applying a high voltage, and generates a high voltage which is applied to the piezoelectric element by applying a low voltage. And a high-voltage generating section 5 to be provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a key switch. More specifically, the present invention relates to a technique for improving the degree of freedom of wiring and realizing low noise.

[0002]

2. Description of the Related Art Various electronic devices, such as personal computers and word processors, are provided with a keyboard as an input device and a liquid crystal display as a display device. The keyboard is provided with a plurality of key switches. I have.

FIG. 3 schematically shows a conventional electronic device.

The electronic equipment a is provided with a key switch b and a drive circuit c for driving the key switch b. The key switch b is configured by arranging predetermined elements in a stack,
It has switching means d and feedback means e.

The switching means d comprises an upper sheet f and a lower sheet g which are arranged vertically with a spacer h interposed therebetween. An upper contact i and a lower contact j are formed on the upper sheet f and the lower sheet g, respectively. . Then, the upper contact i and the lower contact j are arranged in an arrangement hole g formed in the spacer h in a state of facing each other.

The feedback means e exerts a so-called force feedback function of generating vibration when the switching operation is performed by the operator and giving the operator a feeling that the switching operation has been performed. They are arranged in a stacked manner on the means d.

[0007] The feedback means e comprises a pair of conductive sheets l, l, an insulating sheet m, and a piezoelectric element n, and the piezoelectric element n is disposed in the insulating sheet m in a buried state. The pair of conductive sheets 1 and 1 are vertically arranged with the insulating sheet m interposed therebetween, and the piezoelectric element n embedded in the insulating sheet m is located directly above the contacts i and j of the switching means d. . Further, the upper part of the piezoelectric element n in the upper conductive sheet l is formed as an operated part o to be pressed by the operator.

The driving (vibration) of the piezoelectric element n is performed by applying a high voltage.

When the operated portion o is depressed, the portion of the upper sheet f located thereunder is bent, and the upper contact i is brought into contact with the lower contact j to be turned on. When the switching means d is turned on, a predetermined command signal corresponding to the switching operation is output from the drive circuit c, and, for example, characters and the like are input to a liquid crystal display unit functioning as a display device. .

When the operated portion o is pressed, at the same time,
A high voltage is applied from the drive circuit c to the piezoelectric element n. The application of a high voltage to the piezoelectric element n is performed via a step-up transformer p provided separately from the key switch b in the electronic device a. Vibration occurs in the element n, which gives the operator a feeling that the switching operation has been performed.

[0011]

However, in the above-described electronic device a, application of a high voltage to the piezoelectric element n is performed via a transformer p provided separately from the key switch b. In addition, a high voltage is applied to the wiring from the transformer p to the piezoelectric element n.

Therefore, it is necessary to use a wiring which can withstand a high voltage, the type of wiring that can be used is limited, and the influence on other wiring provided from the transformer p to the piezoelectric element n must be taken into consideration. In addition, there is a problem that the degree of freedom of wiring is restricted.

Further, noise is easily generated from the transformer p to the piezoelectric element n due to the high voltage, which may adversely affect the proper use of the electronic device a.

Accordingly, it is an object of the present invention to overcome the above-mentioned problems and improve the flexibility of wiring and realize low noise.

[0015]

The key switch of the present invention comprises:
In order to solve the above-mentioned problems, a switching unit operated by operating an operated part, a piezoelectric element that generates vibration by applying a high voltage, and a high voltage that is applied to the piezoelectric element by applying a low voltage And a high-voltage generating section for generating the above.

Therefore, in the key switch of the present invention,
There is no need to provide a booster circuit outside the key switch.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the key switch of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows the configuration of the key switch 1.

The key switch 1 has required members arranged between a top sheet 2 and a base sheet 3 formed of an insulating material.

A spacer 4 is arranged between the top sheet 2 and the base sheet 3, and the spacer 4 has an arrangement hole 4a. The upper end of the spacer 4 has a protruding portion 4b protruding inward.

On a part of the lower surface of the top sheet 2, an upper contact 2a arranged in the arrangement hole 4a is formed. The portion of the top sheet 2 where the upper contacts 2a are formed is formed as an operated portion 2b on which a pressing operation is performed.

In the arrangement hole 4a of the spacer 4, a piezoelectric transformer 5 and a piezoelectric element 6 are vertically arranged with a common electrode 7 interposed therebetween.

The piezoelectric transformer 5 functions as a high voltage generator for applying a high voltage to the piezoelectric element 6, and generates a high voltage by vibrating. The piezoelectric transformer 5 has a lower contact 5a formed on the upper surface and a common electrode 7 formed on the lower surface.

The lower contact 5a is not formed at one end of the upper surface of the piezoelectric transformer 5. The lower contact 5a is positioned so as to face the upper contact 2a of the top sheet 2, and the upper contact 2a and the lower contact 5a constitute the switching means 8.

The piezoelectric element 6 is formed of a ceramic material, and is connected to the piezoelectric transformer 5 via a common electrode.

A wraparound electrode 9 is formed on the upper surface of the base sheet 3, and the wraparound electrode 9 is connected to a first connection portion 9 a located on the lower surface side of the piezoelectric element 6 and from one end of the first connection portion 9 a. An intermediate portion 9b protruding upward and a second connection portion 9 protruding from an upper end of the intermediate portion 9b and positioned parallel to the first connection portion 9a.
c. Then, the wraparound electrode 9 is connected to the first connection portion 9.
a is connected to the piezoelectric element 6, the intermediate part 9 b is located on the side of the piezoelectric transformer 5 and the piezoelectric element 6, and the second connection part 9 c is connected to the upper surface of the piezoelectric transformer 5. Therefore, the piezoelectric transformer 5 and the piezoelectric element 6 are connected by the wraparound electrode 9. A projecting portion 4b of the spacer 4 is interposed between the second contact portion 9c of the wraparound electrode 9 and the top sheet 2.

As described above, in the key switch 1, the switching means 8, the piezoelectric transformer 5 and the piezoelectric element 6 constituted by the upper contact 2a and the lower contact 5a are disposed between the top sheet 2 and the base sheet 3. , It is thin.

FIG. 2 is a diagram showing a circuit configuration of the key switch 1. As shown in FIG.

The piezoelectric transformer 5 is connected to the piezoelectric element 6 via the common electrode 7 and the wraparound electrode 9. A drive unit 10 provided separately from the key switch 1 is connected to the piezoelectric transformer 5 by contacting the upper contact 2a and the lower contact 5a, and the piezoelectric transformer 5 is connected via the common electrode 7 to the drive unit. 10 is connected. Therefore, the common electrode 7 connects the driving unit 10 to the piezoelectric transformer 5 and also connects the piezoelectric transformer 5 to the piezoelectric element 6.

As described above, in the key switch 1,
Since the connection between the driving unit 10 and the piezoelectric transformer 5 and the connection between the piezoelectric transformer 5 and the piezoelectric element 6 are made by one common electrode 7, the number of parts of the key switch 1 can be reduced and the thickness can be reduced.

The operated portion 2b of the top sheet 2
Is pressed, the top sheet 2 is bent, the upper contact 2a is brought into contact with the lower contact 5a, and a low DC voltage or a drive pulse voltage of about 3 to 5 volts is applied from the drive unit 10 to the piezoelectric transformer 5. Applied. When a voltage is applied to the piezoelectric transformer 5, a high voltage boosted by the piezoelectric transformer 5 is applied to the piezoelectric element 6, and the piezoelectric element 6 vibrates to exhibit a force feedback function, and a switching operation is performed for the operator. Is given as a touch.

When the operated portion 2b of the top sheet 2 is pressed, the force feedback function of the piezoelectric element 6 is exhibited, and at the same time, it is detected that a switching operation has been performed by a detecting unit (not shown). The detection signal is input to a predetermined input unit.

When the pressing operation on the operated portion 2b is released, the bent top sheet 2 returns to the original state, and the contact between the upper contact 2a and the lower contact 5a is released. Therefore, the application of the voltage from the drive unit 10 to the piezoelectric transformer 5 is released, and the vibration of the piezoelectric element 6 disappears.

As described above, in the key switch 1, since the piezoelectric transformer 5 and the piezoelectric element 6 are arranged in the arrangement hole 4a and the two are integrated, the position from the drive unit 10 to the piezoelectric transformer 5 is increased. High voltage is not applied, and the degree of freedom of wiring from the drive unit 10 to the piezoelectric transformer 5 is significantly improved.

In addition, it is possible to suppress the generation of noise between the drive unit 10 and the piezoelectric transformer 5, and it is possible to ensure a proper use state of the device using the key switch 1.

Further, by using the piezoelectric transformer 5 as the high voltage generator, the key switch 1 can be made thinner and the key switch 1 has a simple structure.

The specific shapes and structures of the respective parts shown in the above-described embodiments are merely examples of the specific embodiments for carrying out the present invention. The scope should not be construed as limiting.

[0038]

As is clear from the above description, the key switch of the present invention comprises a switching means operated by operating an operated part, a piezoelectric element which generates vibration when a high voltage is applied, and A high-voltage generating section for generating a high voltage to be applied to the piezoelectric element when a low voltage is applied.

Therefore, in order to generate a high voltage, a high voltage is not applied from the driving section to which the low voltage is applied to the high voltage generating section to the high voltage generating section. The degree of freedom of the wiring is greatly improved.

Further, it is possible to suppress the generation of noise from the driving section to the high voltage generating section, and it is possible to ensure a proper use state of the device using the key switch.

According to the second aspect of the present invention, the switching means is opened and closed when a pair of contacts formed between a pair of sheet members come and go, and a piezoelectric device is provided between the pair of sheet members. Since the element and the high voltage generator are arranged, the thickness of the key switch can be reduced.

According to the third and fourth aspects of the present invention, since the piezoelectric transformer formed of a piezoelectric material is used as the high voltage generating section, the key switch can be made thinner and the key switch can be made thinner. The switch has a simple structure.

According to the fifth and sixth aspects of the present invention, a common electrode connected to the switching means and for applying a high voltage to the piezoelectric element from the high voltage generating section is provided. Since the piezoelectric element and the piezoelectric element are connected via the common electrode, the number of parts of the key switch can be reduced and the thickness can be reduced.

According to the present invention, a common electrode connected to the switching means and for applying a high voltage from the piezoelectric transformer to the piezoelectric element is provided. Are connected via the common electrode, so that the number of parts of the key switch can be reduced and the key switch can be made thinner.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the key switch of the present invention together with FIG. 2, and FIG. 1 is a schematic enlarged sectional view.

FIG. 2 is a diagram showing a circuit configuration.

FIG. 3 is a conceptual diagram showing a conventional electronic device provided with a key switch.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Key switch, 2 ... Top sheet (sheet-shaped member), 2a ... Upper contact point (contact point), 2b ... Operated part, 3 ...
Base sheet (sheet-shaped member), 5: piezoelectric transformer (high-voltage generating section), 5a: lower contact (contact), 6: piezoelectric element, 7: common electrode, 8: switching means

Claims (8)

[Claims] 1. A switching means operated by operating an operated part; a piezoelectric element generating vibration by applying a high voltage; and a high voltage generating a high voltage applied to the piezoelectric element by applying a low voltage. A key switch comprising a voltage generator. 2. The switching means is opened and closed when a pair of contacts formed between a pair of sheet members come and go, and a piezoelectric element and a high-voltage generating unit are arranged between the pair of sheet members. The key switch according to claim 1, wherein: 3. The key switch according to claim 1, wherein a piezoelectric transformer formed of a piezoelectric material is used as the high voltage generator. 4. The key switch according to claim 2, wherein a piezoelectric transformer formed of a piezoelectric material is used as the high voltage generator. 5. A common electrode connected to the switching means for applying a high voltage to the piezoelectric element from the high voltage generating section, wherein the high voltage generating section and the piezoelectric element are connected via the common electrode. The key switch according to claim 1, wherein: 6. A common electrode connected to the switching means for applying a high voltage to the piezoelectric element from the high voltage generating section, wherein the high voltage generating section and the piezoelectric element are connected via the common electrode. The key switch according to claim 2, wherein: 7. A common electrode connected to the switching means for applying a high voltage from the piezoelectric transformer to the piezoelectric element, wherein the piezoelectric transformer and the piezoelectric element are connected via the common electrode. The key switch according to claim 3. 8. A common electrode connected to the switching means and for applying a high voltage from the piezoelectric transformer to the piezoelectric element, wherein the piezoelectric transformer and the piezoelectric element are connected via the common electrode. The key switch according to claim 4.