JPS61230216A - Piezo-electric key with sound output - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to a piezoelectric key with an acoustic output that is used by being superimposed on a display.

[Prior art and its problems 1] Utilizing the properties of a piezoelectric material that generates voltage on the surface of a dielectric material when polarized by mechanical displacement such as pressure, electrodes of a predetermined shape are placed on both sides of a piezoelectric layer made of this piezoelectric material. A so-called piezoelectric key, in which the voltage generated by pressing is extracted as a signal through the electrodes, can be formed thin and transparent, and the polarity changes periodically between the opposing electrodes. When a voltage is applied, sound is output from this piezoelectric layer, so this piezoelectric key is bonded to the surface of a display body and used as a piezoelectric key for manually pressing keys directly from the display screen.

However, conventional piezoelectric materials used were ceramics with translucent properties, which were expensive and did not have very good light transmittance, so they were only used for small display areas such as watches, and the display area was limited. It has the disadvantage that it cannot be used for large CR1 display devices and the like.

[Object of the Invention 1] This invention was made to eliminate the above-mentioned problems, and an object of the invention is to provide a piezoelectric key with an acoustic output that can be superimposed on a large-area display.

[Structure 1 of the Invention] The piezoelectric key with acoustic output of the present invention is a piezoelectric key with a sound output, which is a piezoelectric key for displaying a display body, in which transparent electrodes are formed on both sides of a piezoelectric layer made of a transparent material, making use of the characteristics of a piezoelectric material that mutually converts displacement and voltage. The piezoelectric key is characterized in that a signal is applied between transparent electrodes sandwiching the piezoelectric layer to output sound from the piezoelectric layer.

[Embodiment 1] Hereinafter, an embodiment of the present invention will be explained with reference to FIG. 1, which is an embodiment, and FIG. 2, which is a cross-sectional view of FIG. 1.

1 is a piezoelectric polymer film layer that is a piezoelectric material, for example,
A transparent piezoelectric material such as PVDF (polyvinylidene fluoride) is used. Xl to X are electrodes provided on one surface of the piezoelectric polymer film layer 1, for example, four layered charging electrodes are arranged at predetermined intervals, and the transparency I↑0 (oxidized indium) etc. are used. Yl to Y4 are electrodes provided on the other surface of the piezoelectric polymer film layer 1, and are perpendicular to the electrodes X'1 to X, so that, for example, four layered charged electrodes are provided. The electrodes are arranged in the same manner as the electrodes X1 to X4. 2 and 3 are protective films provided on the electrodes XI to X4 and the electrodes Y1 to Y, and are made of a transparent material. X-engine is electrode X1
to
The drains of the transistor T2 are connected to each other (the connection point is X), and the date of the transistor T2 is connected to the above connection. Connected to point X. At this connection point X, a source VDD is connected for acoustic control.
A P-MOS (P-MOS) lannostar T connected to the potential is connected in the same way.

This connection point X is connected to each electrode XY to X4 by a date switch G+ to G4. E, like Xl, is a MOS resistor T, or T6 and T1, which controls the electrodes Y, and the connection point y connects each electrode Y1 to Y through the date switch G, or G. Connected to Y4.

Control of the piezoelectric switch having the above configuration will be described next. Now, the key S11 corresponding to the intersection of the electrode Xl and the electrode Y2 is pressed with a finger or the like, and as shown in FIG. Suppose that

First, when the date input signal A of the transistor T is made a negative signal and the transistor T4 is turned on, VDD is output to the connection point y, so at this time, the transistor T,
and T41 are turned off.

Then, each day) Gs to G8 are turned on and each electrode Y,
The potential of Y4 is all set to "DD".

Therefore, the potential of the electrode X1 becomes Vc,ov, and the other electrodes X2 to X are in a floating state from the ground potential.

Next, the input signal E of the transistor T is made a negative signal,
When the transistor T1 is turned off, the connection point X is held at VDD by the clamp resistance of the transistor T.

Then, each date GI to G4 is turned ON sequentially by scanning.
be made into Now, when the date G1 is turned ON, the potential at the connection point X becomes VDD v, as shown in FIG. 2, and the output signal F of the transistor T2 becomes -(V DD-v). As a result of scanning, data GIIJf becomes OFF, and when any of the other dates G2 to G is turned ON, the potential of the connection point X becomes the potential VDD held by the transistor T3, and the output signal F of the transistor T2 becomes - V.D.
It becomes D. In this way, only when date G1 turns ON, the output signal F of transistor T2 changes from -VDD to -(V
DI) v), so the pressed electrode X1 of Xfil can be detected.

When the above-mentioned scanning of dates G1 to G4 is completed, the input signal E of the transistor T is made a positive signal and the transistor T1 is turned on, so that the potential of the connection point X becomes the ground potential Vss, and the Tll is OF
It becomes F. Then, each date G1 to G4 is all O.
N, and the potential of each electrode XI to X4 is set to Vss.

Therefore, when each gate of G to G8 is turned off, the potential of the electrode Y becomes V, and the other electrodes Y2 to Y4 become floating from the ground potential Vss. Next, the input signal A of the transistor T4 is made a positive signal, and the transistor T4 is turned off.
When set to FF, the potential at the connection point y is held at VSS by the clamp resistance of the transistor T6. Then, each date G5 to G6 is sequentially turned on by scanning. Now, when the gate G5 is turned on, the potential at the connection point y becomes a beam, and the transistor T becomes active.

The output signal C becomes -V. Gate G5 becomes O due to scanning.
When the transistor becomes FF and one of the dates G6 to G8 turns ON, the potential at the connection point y becomes the potential VSS held by the transistor T6, and the output signal C of the transistor T5 becomes O. In this way, the output signal C of the transistor T changes from O to - only when the date G5 turns ON.
Since the voltage changes to V, the pressed Y-side electrode Y1 can be detected, and thereby the key S11 corresponding to the intersection of the electrodes X1 and Y can be detected.

Date G or G4 mentioned above and Date G5 or G
11 is designed to be alternately scanned in order to detect whether or not there is any manual force applied to the key by pressing it.

Next, when outputting sound from the piezoelectric polymer film layer 1, gates G1 to G and gates G to G8 are used.
are all turned ON, the input signal of transistor T6 is made negative, the input signal H of transistor T3 is made positive, and both are turned OFF.
Make it F. And the transistors T1 and T l l
controls input signals E and D of transistors T4 and T
41 input signal A.

By controlling B, electrodes X1 to X and electrode Y
If a voltage that changes at a predetermined period is applied between 1 and 74, a sound having a frequency of the above period will be output from the piezoelectric polymer film layer 1 at the locations where the electrodes X1 to X4 intersect with the electrodes Y1 to Y, respectively. . Note that by partially controlling the dates GI to G8, the sound can be output only at a predetermined location of the intersection, or by applying a signal with a different period to each intersection, sounds with different frequencies can be output. I can do it.

The film-shaped piezoelectric key with acoustic output described above may be attached to the display surface 5 of the cathode ray tube 4 of a CRT display device, as shown in FIG. It may be attached to the front surface of the plate 6, or it may be provided so as to overlap a large area liquid crystal display section.

In this example, the electrodes X1 to X4 provided on one surface of the piezoelectric polymer film layer 1 and the electrodes Y and Y4 provided on the other surface were provided so as to mutually form a matrix structure. A common electrode may be provided on the entire surface of the pond, and individual individual electrodes may be provided on the surface of the pond.

[Effects of the Invention 1 As detailed above, the present invention provides a method in which the electrodes provided on one surface and the other surface of the piezoelectric layer are arranged so as to face each other,
Since the piezoelectric layer outputs sound by detecting the pressed key and applying a voltage between the electrodes, the piezoelectric layer has a single layer structure, and the piezoelectric key with sound output can be formed thinly. , CRT has good transparency.
A large-area piezoelectric key with an acoustic output that is used to be superimposed on a display device or the like can be manufactured at low cost.

[Brief explanation of drawings]

FIG. 1 is a plan view of a piezoelectric key showing one embodiment of the present invention and a circuit diagram connected to the piezoelectric key, FIG. 2 is a sectional view taken along a-a' of the piezoelectric key in FIG. 1, and FIG. and FIG. 4 are side views showing an example of use. DESCRIPTION OF SYMBOLS 1... Piezoelectric polymer film layer, 2, 3... Protective film, Xl to X, Y, to Y4... Electrode, G
1 to G8...Date, T I -T's t
Tl1tT41...transistor, X+Y...connection point.

Claims (2)

[Claims] (1) In a piezoelectric key for display covering, in which transparent electrodes are formed on both sides of a piezoelectric layer made of a transparent material by utilizing the characteristics of a piezoelectric material that mutually converts displacement and voltage, the gap between the transparent electrodes sandwiching the piezoelectric layer A piezoelectric key with sound output, characterized in that a signal is applied to the piezoelectric layer to output sound from the piezoelectric layer. (2) The transparent electrode includes a plurality of strip-shaped electrodes arranged at predetermined intervals on one surface of the piezoelectric layer, and strip-shaped electrodes arranged at predetermined intervals on the other surface in a direction that intersects with the strip-shaped electrodes. A piezoelectric key with an acoustic output according to claim 1, wherein a plurality of piezoelectric keys with acoustic output are provided with the keys separated from each other.