JPS628556Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is a watch having an electrochromic (hereinafter abbreviated as EC) display, which has a structure that erases the memory contents of the EC display when the battery is removed. Regarding drive circuits.

In recent years, methods have been developed that use EC display materials, which have advantages such as a wide viewing angle and good coloring properties, in the display section of electronic watches. However, EC display materials have the characteristic that once a voltage is applied and the display develops a color, it has a memory effect for a certain period of time even when the voltage is turned off, so the display does not disappear, and in order to erase the color, a reverse voltage must be applied. Because of this feature, even if the user removes the battery, the current time will continue to be displayed on the EC display due to its memory function, and when the battery is inserted again, the clock circuit in the IC will continue to display the current time. The measured time does not necessarily match the displayed time depending on the memory contents of the EC display section. If the time is displayed as is, an imbalance will occur in the charges accumulated in each segment of the EC display section, and the display may not be written or erased correctly, which may prevent the time from being displayed correctly. It was hot. This has been a major problem with the implementation of using EC display materials in the display section of watches.

Therefore, in order to solve this conventional problem, the present invention erases the memory contents of the EC display section to clear the display when it detects the operation of removing the battery from the watch, and when the battery is inserted again, it returns to normal. It is designed to display the time.

A detailed explanation will be given below based on the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention. The time signal forming circuit 7 is composed of an oscillator 2, a frequency divider 4, and a clock circuit 6, and forms a time signal. The oscillator 2 generates a time reference signal, and the frequency divider 4 is a circuit that divides the time reference signal to a required frequency. The clock circuit 6 receives the output signal from the frequency divider 4, measures time, and forms a time signal.

The time display section 13 includes a decoder 8 and an EC display section 10.
and a drive circuit 12, and displays the time based on the above-mentioned time signal. The time signal from the clock circuit 6 is converted by the decoder 8 into a signal for displaying segments on the EC display section 10, and is input to the drive circuit 12. Then, the drive circuit 12 applies a drive signal corresponding to the signal from the decoder 8 to the EC display section 10 in response to an erase pulse and a write pulse to be described later, thereby displaying the time.

The erase pulse generating circuit 27 that generates the erase pulse described above is composed of an OR gate 22 and an erase signal circuit 26, and outputs the erase pulse in accordance with a constant periodic signal output from the time signal forming circuit 7. In this embodiment, a signal that outputs a pulse every 10 seconds from the clock circuit 6 is supplied to the OR gate 22 via the AND gate 14, and an erase pulse is output every time this pulse is output. The erasure signal circuit 26 is, for example, ``Japanese Unexamined Patent Application Publication No. 52-56897'', page 3, upper left column 20.
It is constituted by a part of the circuit described in lines 1 to 15 of the upper right row of the same page, and outputs a signal with a predetermined pulse width.

Further, the write pulse generation circuit 21 is constituted by the write signal circuit 20, and outputs a write pulse following the erase pulse. Write signal circuit 2
0 includes the same configuration as the erase signal circuit 26 and a delay circuit that delays the pulse output by at least the output time of the erase pulse, and a signal that outputs a pulse every 10 seconds from the clock circuit 6 via the AND gate 16. Supplied.

On the other hand, the switching means 19 consists of a switch 18, which will be described later, and detects the operation of removing the battery from the storage section. That is, the switch 18 is configured to be turned on and output a detection signal when the battery is removed, and turned off when the battery is inserted.

The stop circuit 17 is for stopping the output of the constant periodic signal from the time signal forming circuit 7 in response to the detection signal from the switching means 19, and the AND gate 14
and 16. and the AND gate 14,
16 is supplied with the output signal of the switch 18 in addition to the signal from the clock circuit 6 mentioned above.

The display erasing circuit 25 is configured to output an erasing pulse from the erasing pulse generating circuit 27 in response to the detection signal from the switching means 19, and is composed of a one-shot circuit 24. When the one-shot circuit 24 is supplied with the detection signal, it outputs a single pulse having the same pulse width as the pulse every 10 seconds from the clock circuit 6 to the OR gate 22.
The output signal of the switch 18 is supplied to the switch 18.

The operation of this circuit will be explained below.

Normally, pulses every 10 seconds from the timer circuit 6 are input to the write signal circuit 20 via the AND gate 16, and are also input to the erase signal circuit 26 via the AND gate 14 and the OR gate 22. The write signal circuit 20 outputs a write pulse, the erase signal circuit 26 outputs an erase pulse, and the write pulse and erase pulse are input to the EC display section 10 via the drive circuit 12. The time will be displayed.

If the battery is removed here, the switch 18 will
ON, AND gates 14 and 16 are closed, and pulses every 10 seconds from timer circuit 6 are no longer input to write signal circuit 20 and erase signal circuit 26. At the same time, one-shot circuit 24 outputs OR gate 2.
One pulse is input to the erasure signal circuit 26 via 2. Then, the erase signal circuit 26 outputs one erase pulse to the EC display section 10 via the drive circuit 12 to erase the memory contents of the EC display section 10 and clear the display. When the battery is inserted again, the switch 18 is turned OFF and the AND gates 14 and 16 are opened, and pulses from the clock circuit 6 every 10 seconds are sent to the write signal circuit 20 and erase signal circuit 26.
Enter. Then, the time counted by the clock circuit 6 is written and erased on the EC display section 10 again.

In this way, every time you take out the battery, the EC display 1
Since all display contents of 0 are erased, when the battery is inserted again after that, the display on the EC display section 10 will return to the normal time display.

FIGS. 2a and 2b are diagrams showing one embodiment of the switch 18. As shown in FIGS. It protrudes from a hole provided in the lower part of the section 30. A locking protrusion 36 protrudes from the upper part of the battery storage portion 30, and the battery 34
When taking out the battery 34, the positive terminal of the battery 34 must first be taken out at an angle. Furthermore, when removing the battery 34, the contact piece 38 is longer than conventional ones so that the positive terminal of the battery 34 is in contact with the contact piece 38 without separating from it before the switch 18 is turned from OFF to ON. . Therefore, as shown in FIG. 2a, if there is a battery in the battery compartment 30, the operation part 32 of the switch 18 will be pushed down by the battery 34 and turned OFF.
become. FIG. 2b shows the case where the battery 34 has been removed. The operating section 32 of the switch 18 is the switch 1
8 is pushed up by a spring provided inside the switch 18, and the switch 18 is turned on.

By the way, the battery is generally inserted into a battery storage part, and a battery cover is used to protect the battery and to prevent the battery from being directly visible to the user. Therefore, in order to take out the battery, it is necessary to first open the battery cover and then take out the battery, and the above operation is generally referred to as a battery removal operation.

In the second embodiment of the present invention, the switching means detects the opening/closing operation of the battery cover, which is necessary for removing the battery, to appropriately erase the color of the EC display. Figures 3a and 3b show a second embodiment of the present invention.

FIG. 3a shows the case when the battery 34 is inserted, and FIG. 3b shows the case when the battery 34 is removed. The switch 18 has the same structure as shown in FIG. 2, and if the battery 34 is inserted and the battery cover 40 is closed as shown in FIG. 3a,
The operating portion 32 of the switch 18 is pushed down by the battery cover 40 and turned OFF. When the battery cover 40 is opened as shown in FIG. 3b, the operating section 32 is pushed up and turned on.

In this way, remove the battery 34 or remove the battery cover 4.
If you open 0, the switch 18 will turn on and the battery 34 will turn on.
or close the battery cover 40, the switch 18
is turned off, eliminating the inconvenience of the user having to operate a separately provided external operation member.

In this embodiment, a timepiece that only displays the time has been described, but it is of course possible to implement the present invention in a timepiece with an additional function display such as an alarm time display.

As described above, according to the present invention, it is possible to provide an EC display clock that can display the time normally when the battery is replaced.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention. FIGS. 2a and 2b are diagrams showing one embodiment of the switch in FIG. 1, and FIGS. 3a and 3b are diagrams showing another embodiment of the switch. 10... EC display section, 14, 16... AND gate, 18... Switch, 20... Write signal circuit, 22... OR gate, 24... One shot circuit, 26... Erase signal circuit, 34... Battery.

Claims (1)

[Claims for Utility Model Registration] (1) A time signal forming circuit that measures a reference signal to form a time signal, and an electrochromic display section, and a circuit that generates a time signal based on the time signal in response to an erase pulse and a write pulse. a time display section for displaying the time when the time has been set; an erasing pulse generating circuit that supplies an erasing pulse to the time display section for erasing the display using a constant periodic signal outputted from the time signal forming circuit; a write pulse generation circuit that supplies a write pulse for writing a display to the time display section; switching means for detecting an operation of removing a battery from a storage section; An electrochromic device comprising: a stop circuit that stops outputting a constant periodic signal; and a display erase circuit that causes the erase pulse generation circuit to supply an erase pulse to a time display section in response to a detection signal from the switching means. Driving circuit for the tsuku display. (2) The driving circuit for an electrochromic display section as claimed in claim 1, wherein the switching means detects that a battery cover is opened.