JPS5840804B2 - Non-contact key input device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an integrated non-contact key power device using a piezoelectric polymer film as an electromechanical transducer.

Conventionally, a key switch that has multiple electrodes for one key and takes out a code signal is disclosed in, for example, Japanese Patent Laid-Open No. 47-2756.
These switches are all mechanical contact type multi-contact switches.

On the other hand, when a code signal is generated from one key, it is ideal that each signal that makes up the code is generated at the same time, and various efforts have been made to closely resemble this ideal. Seen in Publication No. 29877.

As seen in this example, the conventional multi-electrode key switch that takes out the code signal is a mechanical contact type multi-contact switch, so the multi-electrode structure has to be complicated like a labyrinth. Moreover, since it is a contact type, it has a short lifespan.

Therefore, it was desired to develop a key switch that has a simple structure, has a long life, and has multiple electrodes to generate a code signal.

According to recent research, certain types of oriented optically active polymers, such as polygamma-methyl-L-glucumate, and certain types of polymers subjected to polarization operation (poling) under a high electric field, such as polyvinylidene fluoride, It is known that polymer films prepared by poling vinyl chloride, polyvinyl fluoride, polyacrylonyl-IJ, or a mixture of these with inorganic ferroelectric powder are stable and have high piezoelectricity.

In the application for Japanese Patent Application No. 114708/1984, the present inventors have proposed a non-contact point in which the polymer membrane in the portion corresponding to the key has a structure having piezoelectricity only in the portion necessary for extracting the desired code signal. We proposed a key switch, but in this case, if the desired code signal is complex to locally poll to create a piezoelectric structure, the polling operation becomes complicated, and furthermore, the temperature rise during polling There were also difficulties in manufacturing accuracy, such as expansion of the polymer membrane and misalignment between the electrode and the corresponding electrode surface.

The present invention provides a non-contact key switch that has improved the above points, has a simple structure, has a long life, and has multiple electrodes with good manufacturing precision to generate a code signal. Taking advantage of the fact that polymer membranes can be easily produced, we use polymer membranes that basically have a piezoelectric structure on the entire surface of the block corresponding to at least a part of them as an electromechanical transducer. A non-contact key human-powered device in which a plurality of keys are arranged on a molecular membrane and a plurality of electrical signals are generated simultaneously in response to the operation of - keys. The present invention provides a low-cost, integrated, and highly reliable non-contact key human-powered device because it allows multiple keys to be placed and a single key to easily generate a coded electrical signal. , its structure is as follows.

(a) It has a single polymer membrane, and (b) A plurality of independent compartments are set in the single polymer membrane.

(c) the polymer membrane in the section has piezoelectricity, and d) signal output electrodes are provided on the lower surface of the polymer membrane connecting each of the sections, (wings of the polymer membrane) A plurality of independent bit electrodes are installed on the upper surface in each of the sections, and (f) a plurality of independent conductive paths, the number of which is the same as the number of the bit electrodes, are provided.
The above-mentioned sections are arranged in series, and each conductive path is engaged with each bit electrode in each section in correspondence with 11 pairs, (g) the upper surface side of the polymer film has the Corresponding to each compartment, a key part is provided that presses the inside of the compartment as a unit, (Force) By operating each of the key parts, different code signals are generated from each of the compartments, In at least one of the plurality of sections, the signal output electrode in a portion corresponding to a portion where at least one bit electrode is located is locally removed.

Next, the non-contact key human power device of the present invention will be explained with reference to the drawings.

Note that although a case having 12 keys will be described below, it is not limited to 12 keys, and it goes without saying that it can be applied to cases where there are fewer or more keys than this.

The one shown in FIG. 1 is an example in which the entire surface is made piezoelectric and used as an electromechanical transducer in order to further simplify the polling operation.

That is, the entire surface of the polymer film 11 is made piezoelectric by poling the entire surface or by stretching it, as in the case of poly γ-methyl-L-glutamate, for example.

Bit electrodes 12 for 4-bit encoding are attached to the front surface, and these are connected by a conductive circuit 13.

A signal output electrode is attached to the back surface except for the blank area 14.

A blank section 14 is provided corresponding to 4-bit encoding.

When you press the dotted block 15 with the key, an output signal is generated in the circuit that passes over the part on which the signal output electrode is attached, but an output signal is generated in the circuit that passes on the part on which the signal output electrode is not attached. no output signal is generated.

In this way a coded signal is obtained.

FIG. 2 is a specific example of a key manpower device using the piezoelectric polymer membrane of FIG. 1.

A piezoelectric film 22 shown in FIG. 1 is adhered to a support substrate 21, and a key assembly 23 is mounted thereon.

The signal output electrode of the piezoelectric film is completely shielded by the giddle plate 24.

A rubber sheet 25 may be placed on the shield plate to absorb the force of the key.

In addition, it is preferable to provide a bar 26 bonded to the piezoelectric membrane surface so that the force of the key is applied uniformly to the piezoelectric membrane (rubber sheet,
and only one bar is shown for simplicity).

It goes without saying that it is also possible to press the piezoelectric polymer membrane directly with a finger without using a key, and this case is also referred to as "key part" in the present invention.

In this case, it is preferable to have a structure in which a protective polymer film is placed on top of the piezoelectric film 22, and a plate made of plastic or the like with 12 holes punched therein instead of the key assembly 23 is tightly attached thereon.

According to the present invention having the above structure, when a key is pressed down and mechanical stress is applied to the block of polymer membrane corresponding to the key, the stress is applied at the speed of sound to each of the plurality of independent bit electrodes provided within this block. A voltage is generated at the signal output electrode on the back surface.

The speed of sound is approximately 2.25 ohm, and the electrode existence range of the /Sec key is approximately 1 d, so the signal from each bit electrode will be generated at approximately 1/225,000 sec or less. , this means that the signals from each bit electrode are obtained at virtually the same time, and this simultaneity is achieved by simply placing an extremely simple shaped electrode within the section on the polymer membrane corresponding to the key. It is a distant relative only by being installed in a facility, and as is clear from the conventional contact type, the structure is dramatically simplified, and furthermore, the lifespan is also shorter than that of the conventional contact type. is at most 1 million times, whereas the number of times using the polymer membrane according to the present invention is dramatically increased to over 10 million times.

These effects are the result of extremely effective use of the properties of polymer membranes in multi-electrode switches.Furthermore, in the present invention, a piezoelectric polymer membrane is used in the portion of the block facing the desired bit electrode. The inventors of the present invention proposed the method disclosed in Japanese Patent Application No. 114708/1983 by making the film non-piezoelectric, or simply by removing the common signal output electrode provided on the back surface of the piezoelectric polymer film. There are drawbacks to locally poling the polymer piezoelectric film in the portion corresponding to the key in the application to impart piezoelectricity only in the portion necessary to extract the desired code signal, namely, temperature rise during poling. This also solves the problem of the polymer membrane expanding and causing misalignment with the corresponding bit electrode surface, and the use of such characteristics of the polymer membrane is unprecedentedly useful. It is.

[Brief explanation of drawings]

FIG. 1 is a plan view showing the structure of an electromechanical transducer made of a piezoelectric polymer film used in the non-contact key human power device according to the present invention, and FIG. 2 is an exploded view of the non-contact key human power device according to the present invention. FIG. Brief explanation of drawings, 11...Polymer membrane, 12.
... Electrode, 13 ... Conductive circuit, 14 ...
...Blank section, 15...Block, 21...
... Support substrate, 22 ... Piezoelectric film, 23 ...
...Key assembly, 24...Shield plate, 2
5...Rubber sheet, 26...Bar.

Claims (1)

[Scope of Claims] 1 (a) has one polymer membrane, (b) has a plurality of independent compartments in the one polymer membrane, and (c) has a polymer in the compartment. The membrane has piezoelectricity, (b) signal output electrodes are provided on the lower surface of the polymer membrane connecting each of the sections, and (e) signal output electrodes are provided on the upper surface of the polymer membrane within each of the sections. (b) A plurality of independent bit electrodes are provided, and (f) a plurality of independent conductive paths, the number of which is the same as the number of bit electrodes, are provided by sequentially connecting each of the sections, and each conductive path are engaged with each bit electrode in each section in a one-to-one correspondence; (7) in at least one section of the plurality of sections, at least one code signal is provided in such a manner that a different code signal is generated from each section by operating a portion of each key; A non-contact key manual device, wherein the signal output electrode is partially removed in a portion corresponding to a portion where two bit electrodes are located.