JPS5825356Y2 - electronic clock - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a liquid crystal display type electronic timepiece, particularly to rate measurement of an electronic timepiece using a dynamic driving method.

Conventionally, static drive rate measurement is performed by electrostatic induction between a liquid crystal panel and an electrode plate of a rate measuring device.

When a 32Hz drive voltage is applied to the liquid crystal panel, the upper and lower transparent electrodes act just like a capacitor, and lines of electric force leak through the glass.

When an electrode plate is placed on the top surface of this liquid crystal panel, charges are induced in the electrode plate due to electrostatic induction.

The upper row of FIG. 1 shows the 32 Hz drive voltage, and the lower row shows the detected voltage waveform of the electric field microphone.

In this way, in static drive, the drive voltage is 32H.
The detected waveform is 32 Hz and the waveform height is almost constant, making it easy to measure the rate with a quartz tester.

However, as is well known, static drive requires panel lead terminals for each segment, and when considering the limit of the pitch of the connector (conductive rubber), there is a natural limit to the segments that can be displayed.

In order to eliminate this drawback, we devised a two-part system.

By using multiplex driving methods such as 3-division and dot matrix, it not only displays hours, minutes, and seconds, but also displays the month and month.
In addition to being able to display the calendar for the day and week, the alarm set time, etc., it is also possible to simultaneously display the stopwatch's cumulative measurement value and lap value, as well as a wide variety of other displays. .

However, since the drive waveform produced by the multiplex drive method contains more harmonic components than static drive, it is difficult to detect only the fundamental wave necessary for an electric field microphone, and furthermore, the detection voltage level fluctuates depending on the display state of the liquid crystal. It was difficult to measure rate with conventional quartz testers.

This invention was devised to eliminate one such drawback.
The gist is to easily measure the rate of multiplex drive with two or more divisions.

Next, the present invention will be explained in detail using an example of a two-division multiplex drive.

FIG. 2 shows an embodiment of the circuit of the present invention.

Figure 3 shows the drive waveform of the two-part liquid crystal multiplex and the detection voltage waveform of the electric field microphone.

FIG. 4 is a time chart in rate measurement mode.

First, Figure 2 shows the common waveforms C0M1 and C0M2, which are the basis of two-division multiplex drive.

This will be explained using FIG.

In Figure 2, the A switch used when rate measurement is required is normally open, so the output of inverter 1 is at a high level (
(hereinafter expressed as H), and therefore the binary counter 4
-Ql, 4 Qz-4Q3 and reset set FF5
-a has been reset and therefore resetsera) FF
The output QTM of 5-b becomes a low level (hereinafter expressed as below) via 5-a and 5-b.

In addition, the output of the divider is 512Hz, 256Hz, 12
With 8Hz, N0R6 outputs signal D as shown in the upper part of Figure 3.
Get TR.

Further, by this DTR and the 64 Hz output of the divider, output AC2 is obtained at N0R8, and output AC1 is obtained at N0R7 via inverter 9.

(See FIG. 3 for waveforms of ACl and AC2) DTR is a transmission gate 10-a.

10-b gives AC3.

Next, at 32Hz (32-h shown in FIG. 3), transmission gates (hereinafter referred to as TG) 11-a, 11
Since -c is ON, ACl becomes the waveform of AND12-a via TGll-a, and then becomes C0M1 via 0R13-a.

As mentioned above, since the A switch is not pressed, the Q
Since TM is L, the output of inverter 21 is H and A
Only ACl passes through ND 12-a and OR 13-a.

On the other hand, when 32Hz is H, TG11-c is also ON, and at this time AC3 power; TG-c, AND12-b, 0R13-b
It becomes C0M2 via.

Similarly, when 32Hz is L (Fig. 3 32-1), T
Gll-b and 11-d are turned ON, and C0M1 becomes AC3, and C0M2 becomes AC3.

As described above, the common waveform C of the 2-split multiplex
OMI and C0M2 are obtained as shown in the lower part of Fig. 3.

In Figure 2, when segment N4-b is lit, the output from the decoder is at a high level, so it is passed through AND15-a.
At the high level of 2 Hz, AC2 is applied to OR16 to form a segment lighting waveform.

When segment 14-b is off, the output from the decoder is L.
Therefore, when the signal is H at 32 Hz, KAC1 is applied to 0R16 through AND15-b to create a segment light-off waveform.

Similarly, for C0M2, when the output from the decoder is L at 32 Hz, H is applied when the light is turned on, and L is applied when the light is turned off, thereby creating a light-on/light-off waveform, respectively.

FIG. 3 shows segment drive waveforms when the COMI side segment and the COMZ side segment are lit.

The detection voltage of the electric field microphone of the quartz tester is the third
As shown in the figure, C0M1. C0M2. Each potential change portion of the segment drive waveform has a plateau.

Therefore, the state of the segment drive waveform (liquid crystal display state)
This changes the detection voltage level, making it extremely difficult to detect only the fundamental wave component of the liquid crystal drive waveform.

The above explanation was given when switch A was open, that is, when the output QTM of reset set FF5-b was L, but what happens when switch A is held down for 3 to 4 seconds to measure the rate, that is, when the LCD Consider changing the drive method from multiplex drive to static drive.

When the A switch in Fig. 2 is held down for 3 to 4 seconds or more, the output of inverter 1 becomes H, and the reset of binary counter 4 Ql-4-Q2-4-Q3 is canceled via OR2, and the fourth The counter starts counting as shown in the time chart in the figure.

Then, the rising pulse 20 of the counter 4-Q3 causes the set reset FF5-a to be set, and the set reset FF
Since the output of is connected to the set terminal of the set/reset FF5-b, the set/reset FF5-b is similarly set and the QTM signal is set to H.

When QTM becomes H, the output of inverter 21 becomes L in Fig. 2.
Therefore, the input of AND12-a and 12-b is prohibited, and the output of the inverter 22 is H, so 32Hz becomes 0.
It is input to C0M1°C0M2 via R13-a.

On the other hand, the output of the inverter 23 also becomes L, and the AND15-
The outputs of a and 15-b become L, and with AND17 32
Hz is input, and the output of 0R16 becomes 32Hz.

In other words, segment 14 has 32Hz, segment 1
32Hz is input to 4-a and 14-b, the driving voltage is static drive as shown in the upper part of Figure 1, and the electric field microphone detection waveform of the quartz tester is as shown in the lower part of Figure 1, making it easy to measure the rate. It becomes possible.

After measuring the rate, turn on either A-D switch.
Latch circuit output ■, @.

The set reset FF5-b is reset with a one-shot pulse that is generated only when the switch is turned on.
'l'M is set to L and the liquid crystal is driven in two-division multiplex mode.

(Refer to the lower part of Figure 5) As described above, according to the present invention, it is not only possible to easily measure the rate of a two-division multiplex drive liquid crystal display electronic watch, which was difficult to measure with a conventional quartz tester, but also a two-division The present invention provides a very effective means for liquid crystal display type electronic watches whose drive waveforms are more complex than conventional static drives, such as 3-division or dot matrix drives.

For the sake of explanation, the present invention uses a two-split multiplex drive; however, this example is just one embodiment of the present invention, and it goes without saying that the gist of the present invention is not limited to this embodiment. be.

[Brief explanation of the drawing]

The upper part of Figure 1 shows the conventional static drive voltage, the lower part shows the waveform detected by the electric field microphone, Figure 2 shows an example of the circuit of the present invention, Figure 3 shows the liquid crystal multiplex driving waveform and the detected waveform of the electric field microphone, and the fourth part shows the waveform detected by the electric field microphone. The figure is a time chart in rate measurement mode.

Claims (1)

[Scope of utility model registration request] An electronic timepiece that displays information on a liquid crystal display device using a multiplex drive method, characterized in that it is equipped with all means for changing the drive method of the liquid crystal display device from multiplex drive to static drive only when measuring rate.