JPS58111734A - Portable information collecting device - Google Patents

Abstract

PURPOSE:To obtain the portable information collecting device by which the pressure of atmosphere, especially water pressure, can be detected as a water depth meter, by arranging a transparent piezoelectric element on a light transmitting member such as a cover glass and an optical display panel substrate, or using the transmparent piezoelectric element also as the light transmitting member. CONSTITUTION:In the inner surface of the light transmitting member 1 such as the cover glass of the portable information device such as a wrist watch, a pressure detecting part, wherein the transparent piezoelectric element such as PLZT is held between an upper Nesa electrode 4 and a lower Nesa electrode 6, is arranged. Lead wires 8 and 9 are connected to the electrodes 4 and 6. Said light transmitting member 1 is held by a main body case through a packing 3 in a hermetically sealing mode. The transmparent piezoelectric element 5 can be made to serve the role of the cover glass as shown by the other Figure. In the case of the wrist watch 20, which can be used as the water depth meter, the transmparent piezoelectric element 5 is arranged in the part of the back surface of the cover glass 1 surrounded by a dotted line, and a cover graph 22, which indicates the water depth, is provided in a liquid crystal display panel 21.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a portable information device having a function of detecting atmospheric pressure, particularly water pressure as a water depth meter. is strongly desired.

Pressure sensors used in conventional water depth gauges include:
Water pressure is converted into mechanical displacement by a bellows or Bourdon tube, and that displacement is transmitted to the contact needle.The mechanical displacement generated by receiving water pressure by a bellows or diaphragm causes inductance, capacitance, resistance, etc. There were two main types of methods: converting the signal into an electrical signal and transmitting the result to a display. However, these methods have complicated structures, are large in size and expensive, and require a pressure inlet and a pressure detection chamber, as well as the need to have a waterproof function. As a portable device, it had a fatal flaw. In recent years, S<
An S4 pressure sensor has been proposed that forms a resistive region in a (silicon) diaphragm and utilizes changes in piezoresistance. This sensor is small and inexpensive, which eliminates the disadvantages of conventional pressure sensors that use many mechanical parts, but it also has large variations in manufacturing and a circuit to compensate for the temperature dependence of SI. It is troublesome to control and is very sensitive to moisture containing 54Vi ions.
For these reasons, it has not yet reached a practical level.

The object of the present invention is to eliminate the drawbacks of depth gauges (pressure sensors) such as those on μ, and to accommodate them in portable information devices such as electronic wristwatches and pocketable electronic devices the size of business cards.

That is, the present invention provides a structure in which a translucent member such as a cover glass or an optical display panel substrate of the above-mentioned portable information device has a function of detecting atmospheric pressure (particularly water pressure), and pressure detection is carried out in one piece. The purpose is to provide a portable information device with various functions.

Portable information devices with waterproof functionality, especially wristwatches, have a strong structure and are also large in size, so there is plenty of room to accommodate a pressure sensor to add a new pressure detection function. There are almost no However, since transparent members such as glass and optical display panel substrates are located on the front of watches,
After considering the novel idea of providing these translucent members with a pressure detection function, the inventor found that (1) they respond sensitively to changes in pressure because they are in contact with the atmosphere;

- Sensitivity can be increased because the area of the pressure detection part can be made the same as that of a light-transmitting member such as a cover glass.

■It has a simple structure and can be used.

■There is no space required for the pressure detection section.

■Since the cover glass has a detection function, waterproof construction is easy.

It has been found that significant advantages such as n can be obtained.

Now, as a result of various considerations in order to provide a pressure detection function to a translucent member, we found that a method of arranging a transparent piezoelectric element such as PLZT on a translucent member was found to be able to detect pressure on a translucent member as described above. It turns out that this can be achieved without sacrificing the advantages of adding functionality. Transparent piezoelectric element binding 1 is PbLa (Z
rTi) oa e Abbreviation FLZT'i beginning metoshite, P
Many compositions are known, such as b (ZrTi)-〇, and BaTi0@ system. These products are produced by the hot press method, in which raw material powder is filled into a T-press mold and synthesized while applying high pressure in an oxygen gas atmosphere at approximately 1200°C or higher, and by thin film forming techniques such as sputtering and vapor deposition. P can be formed by the following method. in general,
The refractive index of transparent ceramics is about 2.5, and the transmittance for short wavelength light is low, making it appear light brown in color. The transparent electrode provided on the transparent piezoelectric material contains 1% O, -8% 0. (
It is usually formed using methods such as vapor deposition or sputtering. To has a refractive index close to 1.6 and also serves as an antireflection film.

The present invention will be specifically explained below using Examples.

FIG. 1 shows a first embodiment of the present invention.
3 indicates the case body, and 3 indicates the cover glass, which serves to maintain confidentiality between the cover glass 1 and the case 2. (The waterproof structure of an actual wristwatch is quite complicated, but
This is simplified because it is not directly related to the gist of the present invention.

) 4 is the upper Nesa electrode (To film), 6 is the lower Nesa electrode,
5 is a transparent piezoelectric element such as 5-PLZT. Reference numerals 8 and 9 are leads connected to the upper and lower Nesa electrodes.

Such a structure is what is called a unimorph structure, and when a voltage is applied to the leads 8 and 9, displacement (vibration) perpendicular to the surface of the lead occurs due to a piezoelectric reverse effect. On the other hand, when the external pressure is at the cutting edge, the piezoelectric effect causes the lead 8,
A voltage is generated between the terminals 9 and 9. When a portable information device having a structure as shown in FIG. 1 is submerged under water using NFC, the displacement that occurs in the translucent member 1 and therefore the transparent piezoelectric element 5 due to the water pressure depending on the water depth is as shown in FIG. 2. become that way. FIG. 2 is a simplified version of the structure shown in FIG. 1, showing only the cover glass 1 and the transparent piezoelectric element 5. (a) shows the case in the atmosphere, where the circular pressure and external pressure are the same. (b) shows a case where the piezoelectric element is immersed in water, and the piezoelectric element is bent due to water pressure as shown by the arrow. (C) is also greatly bent because of the water pressure applied to it. As shown in μ, there is a one-to-one correspondence between the water depth and the amount of deflection (strain) of the piezoelectric element, so it is possible to measure the water depth by utilizing the piezoelectric phenomenon. In other words, in Fig. 1, when measuring water depth, the piezoelectric element 5 (cover glass 1) has a total piezoelectric inverse effect.
When vibrated, a strain corresponding to the water depth is applied, so the water depth can be determined based on the frequency difference between the vibration frequency and the vibration frequency when photographing in the atmosphere. It is also possible to make use of the piezoelectric effect to convert water pressure depending on the water depth into electrolysis using a piezoelectric element for discrimination. As described above, according to the present invention, a light-transmitting member can be easily provided with a pressure detection function. Moreover, the light-transmitting member and the transparent piezoelectric element can be manufactured using conventional techniques, and there is a great advantage that only a simple electronic circuit for processing electrical signals in response to pressure is newly required.

Another embodiment of the invention is shown in FIG. Unlike the structure shown in FIG. 1, the structure is such that a transparent member such as a cover glass is made of a transparent piezoelectric element. Since the symbols correspond to those in FIG. 1, individual parts will not be described. Here, the transparent piezoelectric element requires strength, so it is molded only by the hot press method.When pressure is detected by the vibration frequency difference using the piezoelectric inverse effect, it is necessary to In order to vibrate, the piezoelectric element must be curved in advance into a spherical shape as shown in the figure.Such a structure has a small number of parts and is easy to assemble, making it suitable for producing large tonic tones.

FIG. 4 shows a case where a surface acoustic wave (SAW) resonator 11't-configuration 5 is formed on a transparent piezoelectric element 5. Here, 131 is an interdigital electrode, and 12 is a grating reflector in which a large number of reflective strips are periodically arranged. 14,
15 is an electrode terminal. It goes without saying that each electrode is desirably a transparent electrode such as a TO material. This piezoelectric element may be attached to a cover glass as shown in FIG. 1, or it may be used as a cover glass as is as shown in FIG. 3. For pressure detection, a method that measures the deviation of the same wave number of oscillation of 5AW11 according to pressure is suitable. Although not shown, the electrode terminals 14, . 15 is naturally connected to the electronic circuit.

FIG. 5 shows an example of a digital watch having a waterproof structure as a portable information device according to the present invention.

A transparent piezoelectric element (
The part surrounded by the dotted line] 5 is the arrangement. LCD display barel 2
1 is provided with a bar graph indicating the water depth. According to the present invention, it is clear that there will be no problems in terms of design and structure even if a pressure detection function is added.

As described above, by arranging a transparent piezoelectric element in the translucent member of the portable information device according to the present invention, a pressure detection function can be easily added, making it possible to make a water depth meter portable, which has been particularly desired in recent years. It became. Also, since a depth gauge is included as a function of the portable information device, the amount of information underwater will further increase. For example, a wristwatch has a time signal function and a timer function. Water depth measurement function is possible. It should be noted that the translucent member requires a certain degree of strength and cannot be made thin, so it is not suitable for use in detecting sensitive pressure (for example, changes in atmospheric pressure).

[Brief explanation of drawings]

FIG. 1 is an embodiment of a portable information device of the present invention, and is a sectional view of a pressure detection section. Figure 2 is a schematic diagram showing how the cover glass and pressure element are displaced by external pressure. FIG. 3 is an embodiment of the portable information device of the present invention, and is a sectional view of a pressure detection section. FIG. 4 is an embodiment of the portable information device of the present invention, and is a schematic diagram of a pressure detection section. FIG. 5 is a schematic diagram showing an embodiment of the portable information device of the present invention. 1. Translucent member 20. Case 3°. Packing ring 4°, upper Nesa electrode 6°, lower Nesa electrode 5. Transparent piezoelectric element 1100 surface acoustic wave C/AV) resonator 20,. Applicant for digital watch and above Daini Seikosha Co., Ltd. 10- Department/m f Body 3 Dankei 4m 5th m 22 II

Claims (3)

[Claims] (1) A portable information device characterized by having a pressure detection function by disposing a transparent piezoelectric element on a light-transmitting member such as a cover glass or an optical display panel substrate. (2) The portable information device according to claim 1, characterized in that a transparent piezoelectric element is disposed on the back surface of the light-transmitting member. (3) The portable information device according to claim 1, wherein the transparent piezoelectric element also serves as a translucent member.