JPS609756Y2 - LCD display device for watches - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a device that displays an electronic timepiece using a liquid crystal display.

Conventional electronic watches, which are purely electronic, display the time directly as numbers digitally, which is very convenient because the current time can be read directly as numbers. When reading the time difference between two times, it was not possible to read it intuitively, and one had to calculate it in one's head.

Therefore, as a highly accurate timepiece, it was driven by a step motor using the output of an electronic circuit, and the motor rotated the hands to display the time in the same way as conventional wind-up watches.

However, such a pointer display cannot be constructed from a purely electronic circuit, and therefore loses its characteristics as an electronic timepiece.

Therefore, purely electronic analog display devices have also been proposed.

However, in conventional devices of this type, a part of the minute hand also serves as the hour hand, so the display is not continuous, but is cut off in the middle, which is unsightly.

This invention provides a liquid crystal display device for an electronic timepiece that is purely electronic and displays minutes in one continuous line, similar to conventional hands.

Hereinafter, an embodiment of the liquid crystal display device for a watch according to this invention will be described with reference to the drawings.

Two glass plates 11 and 12 are closely opposed to each other, and a liquid crystal 13 is interposed between the glass plates 11 and 12.

Six rod-shaped electrodes S0 to S5 are formed on the inner surface of one glass plate 11.
9 are formed radially at equal angular intervals, and these rod-shaped electrodes S.

-5se, a wide ring-shaped inner electrode 14 centered on its radiation center, and an outer electrode 15 concentric with the outside thereof.
are respectively formed on the inner surface of the other glass plate 12.

Furthermore, on the outer extension of the rod-shaped electrode for hour display,
Electrode S.

Two correspondingly short electrodes T.

And from now on, every 5 lines, that is, 5 minutes, 1 snout, im---
Rod-shaped electrodes Ss, Sto, S□ indicating the positions of -------
5... Corresponding to electrode T1゜T2? T
3... are formed on the inner surface of the glass plate 11, respectively.

Further, a small circular electrode 16 is formed on the glass plate 11 at the radiation center of the rod-shaped electrode, and a small circular electrode 17 is formed on the glass plate 12 opposite to this electrode 16.

In this device, the inner electrode 14 and the outer electrode 15 are continuous when viewed from the direction perpendicular to the plate surface, but their boundary is in the direction perpendicular to the plate surface, as shown in a partially enlarged view in FIG. They are shifted so that they do not touch each other.

In the illustrated example, the outer peripheral edge of the inner electrode 14 extends into a ring-shaped groove 18 formed in the glass plate 12, and the bottom of the groove 18 has a tapered surface 19 on the inner electrode 14 side that coincides with the glass plate surface.
and an inner electrode 14 are continuously formed on the bottom surface 19 of the groove 18, and the outer wall surface of the groove 18 is perpendicular to the glass plate 11.

The wall surface creates a step t1 between the electrodes 14 and 15, thereby insulating the two electrodes.

When displaying the hour, a voltage is applied between the inner electrode 14 and one selected rod-shaped electrode, and the outer electrode 15
No voltage is applied to.

When displaying minutes, a voltage is applied between both the outer electrode 15 and the inner electrode 14 and one selected rod-shaped electrode.

The switching display is performed at such a high speed that the minute and hour displays are visually continuous.

For example, as shown in FIG. 4, the oscillation output from a crystal oscillator 21 is frequency-divided by a frequency dividing circuit 22, its output is further supplied to a bone frequency dividing circuit 23, and its output is supplied to a time frequency dividing circuit 24. Ru.

The output frequency of the frequency dividing circuit 22 corresponds to 1 second, and its output is branched and supplied to the seconds display drive circuit 25, and this output voltage is applied between the small circular electrodes 16 and 17 for seconds display.

The frequency division contents of the bone frequency division circuit 23 are supplied to the division drive circuit 26.

The dividing drive circuit 26 includes a decoder, and depending on the content of the bone frequency dividing circuit 23, one of the rod-shaped electrodes 80 to 5 is selected, and the selected rod-shaped electrode and the inner electrode are selected. A voltage is applied between the outer electrode 14 and the outer electrode 15 .

Further, the frequency dividing state of the time frequency dividing circuit 24 is similarly decoded by the time driving circuit 27 and sent to the rod-shaped electrode S.

-559 is selected, but in this case, every 5 consecutive rod-shaped electrodes in one hour, that is, one rod-shaped electrode is selected in sequence every 12 minutes, and a voltage is applied to it and the inner electrode 14. .

The driving of the rod-shaped electrodes by the minute drive circuit 26 and the hour drive circuit 27 is performed by switching alternately as described above.
In that case, a voltage is applied to the inner electrode 14 and the outer electrode 15 when the minute drive circuit 26 outputs an output.

In other words, a signal with a speed so fast that it is not perceptible to the eye is transmitted to the frequency dividing circuit 2.
The signal is taken out from the middle of the frequency dividing stage 2 through the terminal 28 and is directly supplied to the outer electrode 15 and also supplied to the inner electrode 14 through the OR circuit 29.

Also, the output from the terminal 28 of the frequency dividing circuit 22 is connected to the inverter 31.
The signal is supplied to the OR circuit 29 through the gate.

Therefore, the inner electrode 14 is always energized and selected, while the outer electrode 15 is selected with every pulse from the terminal 28 and not during the interval between each pulse.

The signal at terminal 28 is also supplied to minute drive circuit 26, and only when this signal is supplied is the output of minute drive circuit 26 applied to the selected display element.

Similarly, the output of the inverter 31 is supplied to the time drive circuit 27, and only when this is supplied, a voltage is applied to the bar-shaped display element selected by the time drive circuit 27.

According to this display device, for example, as shown in FIG.
In a state of confusion, the inner electrode 14 is always at a high level, the outer electrode 15 appears alternately at a high level and a low level, and the rod-shaped electrode S2 alternately appears at a high level and a low level. When the outer electrode 15 is at a low level, this rod-shaped electrode S2 is at a low level, so that the display on the selected rod-shaped electrode S2 does not cover its entire length, but only the portion facing the inner electrode 14, as shown in FIG. This is a short display as shown in , and is displayed between the 1st verse and 1 o'clock.

A high level and a low level appear alternately on the rod-shaped electrode SaO, and since this is in the opposite phase to the rod-shaped electrode S2, when this is a low level, both the inner electrode 14 and the outer electrode 15 are at a high level, so that The selected rod-shaped electrode S30 is displayed over its entire length.

Therefore, as shown in Fig. 5, a long display is obtained at the 3@ position, and from this 12fJ! f3e is displayed, that is, the display is similar to the display using a conventional clockwork type pointer.

Of course, the display electrode S is not selected.

, Sl, S3, etc. are all high level and not displayed.

Furthermore, as mentioned above, the second display electrodes 16 and 17 flash every second, indicating that the clock is operating.

Although the equal division display and hour display are performed alternately, the switching speed is so fast that they appear to be displayed continuously.

Furthermore, a display element T is provided to make it easy to understand the position of each time.

~T□1 is always given a low level and emits light when its outer electrode 15 becomes high level, but this display also appears to be displayed continuously.

In this way, a display similar to the conventional pointer display is performed purely electronically, and in this case, the long hand display is displayed over its entire length, making it easy to see.

That is, as shown in FIG. 3, the inner electrode 14 and the outer electrode 15
Since the boundary with the board is in contact with the plate surface when viewed from the perpendicular direction, the minute display is displayed as a single rod-shaped element without any breaks.

[Brief explanation of drawings]

Fig. 1 is a plan view showing an example of a watch liquid crystal display device according to this invention, Fig. 2 is a sectional view taken along the line M, Fig. 3 is an enlarged view of the portion indicated by C in Fig. 2, and Fig. 4 is an electrical FIG. 5, a block diagram of the circuit portion, is a diagram showing an example of a display. So””Sss: Rod-shaped electrode, 14: Inner electrode, 15:
Outer electrode, 26: minute drive circuit, 27: hour drive circuit.

Claims (1)

[Scope of utility model registration request] Rod-shaped electrodes for time display are arranged in six shapes at equal angular intervals, and an inner electrode and an outer electrode are provided facing the rod-shaped electrodes and centered around the center. A clock in which a liquid crystal is interposed between the inner electrode and the outer electrode, and the inner electrode and the outer electrode are continuous when viewed from the direction perpendicular to the plate surface, but the boundary portions thereof are offset without being connected to each other in the direction perpendicular to the plate surface. liquid crystal display device.