JPS5939669Y2 - electronic clock - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an analog electronic timepiece that displays the day and day of the week, in which the day and day of the week are displayed digitally using electro-optic materials.

In recent years, with the development of electro-optic materials such as PLZT,
Display devices using this material are being developed.

Digital display devices using PLZT have the advantages of fast response speed, memory effect, and can be made thinner, but have the disadvantage of requiring a high driving voltage of 30 to 70 volts.

On the other hand, in conventional electronic watches that display the day and day of the week using a date wheel and day wheel, there is a limit to how thin the watch can be made because of the head wheel and day wheel.

The purpose of the present invention is to use a piezoelectric material as a drive power supply part of a display device using an electro-optic material such as PLZT, so that it can be used as a display device without any problems even at high drive voltages, is extremely thin, and To provide an electronic timepiece equipped with an unmodified calendar mechanism simply by adding a memory circuit to a circuit part.

Next, the present invention will be explained in detail based on the drawings.

FIG. 1 is a block diagram of an electronic timepiece according to the present invention.

An oscillation source 1 such as a crystal oscillator, a frequency dividing circuit 2 that divides the frequency into time signals such as hours, minutes, and seconds, a motor part 5 that converts the seconds signal into hand movement, and the seconds and minutes 9 o'clock signals that come from it. Converting the fourth wheel to 13. It is composed of a transmission system consisting of a center wheel & pinion, a 14° hour wheel 15, etc., and a decoder circuit 3 and a drive circuit 4 for driving a digital display section 12.

The driving power source for the digital display section 12, which is made of an electro-optical material such as PLZT and displays the day and day, is provided by a piezoelectric material 9 and an hour wheel 1.
When switching between the day and the day, an impact can be applied by the impact lever 7 to obtain a predetermined driving voltage by the switching gear 10 interlocked with the switching gear 5.

The gear 10 for switching the date and day of the week operates the impact lever 7 once a day by the movement of an operating pin 11 attached around the gear 10 for switching.

The spring 8 attached to the impact lever 7 is installed to increase the impact force applied to the piezoelectric material 9, and is not necessarily required if the impact force of the impact lever 7 alone is sufficient.

The relationship between the impact force F applied to the piezoelectric material 9 and the output voltage V is given by the following equation, where S is the area of the piezoelectric material to which the impact is applied, S is its length, and g is the piezoelectric output coefficient.

■'''' g F 5 The driving voltage of a display device using PLZT as an electro-optic material is 4
0 to 70 volts.

This voltage is applied to other piezoelectric ceramics based on lead zirconate titanate.
It can be obtained sufficiently with Tsukusu materials.

Figure 2 shows the output voltage of PLZ when a shock is applied to the piezoelectric material.
1 shows a driving circuit for driving one segment of an electro-optic material display, such as T.

The output voltage from the piezoelectric material 9 by the impact lever 7 is CM
A writing signal is input from A and an erasing signal is input from B according to the signals from the decoder circuit applied to the drive circuit unit 17 consisting of O8' and U to control the display element 18 of one segment of the electro-optical display device. .

That is, if a writing signal is given from A at or slightly before the day and day of the week are switched, the display is displayed by the voltage from the piezoelectric material when the day and the day of the week are switched.

If the display device uses a highly insulating material such as PLZT and there is no residual polarization because the day and day signals displayed at this time are quadratic with respect to the electric field, the display will be maintained even if these 11 electric fields are not applied. Ru.

This maintained state of display hardly changes even for two weeks or more.

The display can be maintained for more than one day by impacting the piezoelectric material about - times or twice, which is sufficient for displaying the date and day of the week.

When switching or erasing the day or week, send the erasing signal to B before switching the day or day and adding the write signal.
and destroy it.

If a material with a second-order electro-optic effect without residual polarization (9/65/35PLZT, etc.) is used, this signal will cause the accumulated charge in the display element to be discharged by a short circuit due to the cancellation signal. belongs to.

If the material has residual polarization, one more piezoelectric material may be added to apply a reverse voltage for cancellation.

Even slight differences in the impact applied to the piezoelectric material by the impact lever can cause considerable variation in the output voltage of the piezoelectric material.

When displaying by changing the retardation due to the electric field of an electro-optic material, variations in the output voltage may cause the retardation to change and become colored, or the display may appear pale due to the color variation.

To prevent this, a constant voltage diode 16 for high voltage (approximately 70 volts) is inserted.

By inserting this constant voltage diode, the voltage applied to the display element 18 can be kept constant.

FIG. 5 is a plan view showing an embodiment of the display according to the present invention, in which the day and day of the week are displayed using four digits.

FIG. 4 is a sectional view of FIG. 5.

A digital display element made of an electro-optical material can be inserted into the day and week display window portions of the dial 21 made of a metal material.

The dial plate 21 is provided with an insulating thin film 28 on the back surface, and a lead electrode 26 is provided thereon.

Electrical connection with an external circuit portion can be achieved by providing a connecting pin 27 on each lead electrode 26 to electrically connect to an external circuit terminal.

The digital display element is provided with transparent electrodes 20 and 25 for segments on both sides of an electro-optic material 22 such as PLZT.

Polarizing plates 19 and 24 are provided on both sides, and a reflecting plate 23 is provided on both sides.
will be established.

Since the thickness of an electro-optic material such as PLZT is extremely thin, 50 to 300 microns, the total thickness of the digital display element can be reduced to 0.7 to 1 inch.

Electrical connection between the electrodes of the digital display element and the lead electrodes on the back of the dial can be achieved by pulling out the electrodes on the polarizing plate 24 and bonding these electrodes and the lead electrodes via a conductive material 29.

As described above, according to the present invention, by using a piezoelectric material as a high-voltage power source, even a display device with a relatively high drive voltage such as PLzT can be used as a low-voltage, low-power drive device. It is possible to provide an electronic timepiece that is extremely thin and has an unmodified calendar mechanism simply by adding a memory circuit to the circuit portion.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an electronic watch according to the present invention, Fig. 2 is a drive circuit diagram using a piezoelectric material as a power source to drive a display device using an electro-optical material, and Fig. 3 is a dial plate of an electronic watch according to the present invention. FIG. 4 is a cross-sectional view of the dial part in FIG. 3. 0 1... Oscillation source, 2... Branch circuit, 3... Decoder circuit, 4... Drive Circuit, 5...Motor section, 6...
Rotor, 7...Impact lever, 8...Spring, 9...
Piezoelectric material, 10... Switching gear, 11... Operating pin, 12... Digital display section, 13... Fourth wheel, 14
... Second wheel, 15... Hourly wheel, 16... Constant voltage diode, 17... Drive circuit section, 18... Display element,
19.24...Polarizing plate, 20.25...Transparent electrode,
21...Dial plate, 22...Electro-optical material, 23...
-Reflector plate, 26... Lead electrode, 27... Connection pin, 28... Insulating thin film, 29... Conductive material.

Claims (2)

[Scope of utility model registration request] (1) When a button is pressed on an electronic watch that displays time information in analog and digital form, the piezoelectric material necessary to drive the digital display part using an electro-optic material is generated by applying an impact to the piezoelectric material and the rotary driving force from the analog part. An electronic timepiece characterized by having a digital display section that obtains a driving voltage. (2) An electronic pump according to claim 1 of the utility model registration claim, characterized in that a constant voltage diode is provided in a circuit that obtains a driving voltage using a piezoelectric material.