JPS5887590A - Electrochromic display - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention aims to improve an electrochromic (hereinafter referred to as EC) display device that normally displays the time, and more specifically, to improve the electrochromic (EC) display device that normally displays the time.
The present invention relates to an EC display device that changes the display density of a time display displayed on the EC display device according to each time zone when the brightness of the surrounding environment differs depending on the time zone, such as at night.

Recently, with the spread of electronic watches, especially quartz watches, demands for low cost, thinness, and long life have become stronger. In order to meet this demand, it is essential to create a watch that uses a small battery with a small capacity by reducing power consumption.

Conventionally, in quartz wristwatches, an EC display element has been cited as one of the display elements for digitally displaying the time.
By changing the application time or writing current value (coloring current value), it is possible to change the display density.

However, displaying the time by constantly increasing the display density is
During times such as daytime (when the surrounding environment is bright) when the time display is easy to read even if the display density is relatively low, this results in wasted power consumption. Although this can reduce power consumption, it is impossible or extremely difficult to read the displayed time at night when the surrounding environment is dark, so it is necessary to install lighting equipment such as lamps, which is costly. Moreover, even if a lamp is provided to make it easier to read the time display contents, there are drawbacks such as restrictions on operability such as pressing the button for the lamp.

The purpose of the present invention has been made to eliminate the above-mentioned drawbacks.
The present invention aims to realize an EC display device that reduces power consumption by selectively switching the display density of the time display and makes it easy to read the time display contents at all times.

The present invention will be described in detail below based on the drawings.

FIG. 1 is a block diagram of an electronic wristwatch showing an embodiment of the present invention, and FIG. 2 is a time chart showing main voltage waveforms in FIG. 1.

In FIGS. 1 and 2, 1 is a crystal oscillation motor, 2 is an oscillation circuit that uses the crystal oscillator 1 as a reference time signal source, and 6 is a circuit having the same period as each other as shown in FIG. 4 is a clock circuit, 5 is a decoder, 6 is an EC display element, and 7 is a time zone externally set. 8 is a memory circuit that stores the time zone set by the operation of the external operation means 7; 9 is a memory circuit 8 that stores the time zone according to the timing contents of the timekeeping circuit 4; It is compared whether or not it falls within the range of the stored time zone, and if the comparison result is within the range of the time zone, logic ``1'' is executed.
A comparator circuit 10 that outputs a level signal P3 selects either the signal P1 or the signal P2 sent from the frequency divider circuit 6 according to the logic state of the signal P3 of the comparator circuit 9 and outputs it as a signal P4. A selection circuit 11 is a drive circuit that drives the EC display element 6 to color or decolorize the content of the signal from the decoder 5 for a drive time width determined by the pulse width of the signal P4.

Next, the operation of the embodiment will be explained based on FIG.

A time period in which the display density of the EC display element 6 is to be displayed darkly is input to the memory circuit 8 via the external operation means 7 and is stored therein.

The signal generated by the oscillator circuit 2 is sent to the clock circuit 4 via the frequency divider circuit 3, and the time measurement contents of the clock circuit 4 are changed. The comparison circuit 9 compares the time measurement contents of the clock circuit 4 with the time period stored in the storage circuit 8, and when the time period includes the time period contents, outputs a signal P of 11'' level. However, when the time period does not include the time measurement content, a signal P of v level is output.

When the signal P takes the logic 11 level, the selection circuit 10 selects the signal P1 and outputs it as the signal P4 to the drive circuit 11. When the signal P is at the 'ON' level, the selection circuit 10 selects the signal P and outputs it as the signal P4. It is output to the drive circuit 11 as P4.

On the other hand, the decoder 5 decodes the time information of the clock circuit 4 and sends it to the drive circuit 11.

The drive circuit 11 provides a coloring or decoloring driving operation to each segment of the EC display element 6 according to the content of the output signal from the decoder 5 while the pulse P4 is at the "1" level.

Therefore, when the selection circuit 10 selects the signal P1 with a large duty ratio and outputs it as the signal P, the drive circuit 1
1, the time width in which the EC display element 6 is driven is long)
Therefore, the EC display element 6 is displayed darkly, and the selection circuit 1
When a signal P with a small duty ratio of 0 is selected and outputted as the signal P4, the time width during which the drive circuit 11 drives the EC display element 6 becomes shorter, so the EC display element 6 displays a faint image. It turns out.

Incidentally, even if the external operation means 7 is removed from the embodiment shown in FIG. 1 and a fixed time period is set in the memory circuit 8, the operation of the present invention will not be impaired.

As an example, if the time zone P3 stored in the memory circuit 8 is set to the time from 6:00 pm to 6:00 am, the signal P4 of the selection circuit 10 is set when the surrounding environment is dark at night.
outputs a signal P with a large data ratio, so EC
The display element 6 will display darkly. In addition, since the selection circuit 10 outputs the pulse P2 during the remaining half day from 6:00 a.m. to 6:00 p.m., the EC display element 6 is displayed dimly.

Further, as another embodiment, a switching circuit (not shown) is provided between the clock circuit 4 and the decoder 5, and the switching circuit uses the external operation mode signal as a switching signal to switch between the signal of the clock circuit 4 and the memory circuit 8. The time period stored in the memory circuit 8 can also be displayed by the EC display element 6 via the decoder 5 and the drive circuit 5.

As described above, according to the present invention, the display density of the EC display element is switched depending on the time of day, and the display is displayed darkly at night when the surrounding environment is dark, thereby making it easier to read the time at night, and using lighting means such as a lamp. can be made unnecessary. Also, by displaying the screen in a dim light during the daytime when the surrounding environment is bright, unnecessary power consumption can be prevented and power consumption can be reduced.

This makes it possible to respond to time lags in environmental changes caused by regional differences, and allows settings to be made to match the user's daily rhythm (time of day when the watch is used), resulting in low power consumption and easy to read display content. It becomes possible to easily realize an EC display device.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention,
FIG. 2 is a time chart diagram illustrating the operation of FIG. 1. 2... Oscillation circuit 6... Frequency divider circuit 4... Timing circuit 5... Decoder 6... EC display element 7... ...
External operation means 8... Memory circuit 9...
... Comparison circuit 10 ... Selection circuit 2nd rlA

Claims (1)

[Claims] an oscillation circuit, a frequency division circuit that divides the frequency of a signal from the oscillation circuit and outputs a plurality of signals having mutually different duty ratios, a timekeeping circuit that inputs the frequency division signal from the frequency division circuit; A decoder that receives a clock signal from a clock circuit, a memory circuit that stores a time zone, a comparison circuit that compares the time zone of the memory circuit with a time zone to which time measurement contents of the clock circuit belong, and the comparison circuit. a selection circuit that selectively outputs one of a plurality of signals having different duty ratios from the frequency dividing circuit according to an output signal from the circuit, and receives a signal from the decoder and a signal from the selection circuit;
An electrochromic display comprising: a drive circuit whose driving time width is a time width determined by a signal from the selection circuit; and an electrochromic display element that is driven to be colored or decolored by the drive circuit. Device.