JPS58114092A - Electrochromic display driving system - 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 relates to a driving method for an electrochromic (hereinafter abbreviated as EC) display device, in which display density is made uniform between segments.

Unlike a liquid crystal display device, an EC display device is a passive display device that is capable of bright and clear display and has memory properties, but its current consumption is an instantaneous current of several tons during write and erase drives. +mA/ctA. Therefore, as the display area increases, the load on the power supply and drive circuit increases, so when displaying numbers and characters by segment display etc., the number of new segments to be written The display density differs each time the total area of the segments to which display writing is applied changes.Also, if you try to make the display density as uniform as possible, the power supply and drive circuit will become larger, and a small display device powered by a battery will be required. This poses a problem for Proposition 4.

The present invention has been made to solve the above problems, and when numbers and characters are displayed using a combination of independent segments, by sequentially displaying each segment, the instantaneous current consumption is reduced. This is an attempt to make the concentration uniform between the two.

The present invention will be explained in detail below based on examples.

FIG. 1 is a diagram of a so-called "Japanese character" numeric display pattern consisting of seven segments of 3% g. Referring to Table 1, the lighting state of each segment when the numbers 0 to 9 are displayed using these seven segments will be explained. The leftmost column of Table 1 shows the display form of each number in a display using segments, and the lighting status of display segments a to g for each number is determined by the following rules using numbers and cross marks. Shown in the table. In other words, the numbers 1 to 7 in the table indicate the lighting state (ON), and the X mark indicates the non-lighting state (OFF state). The number 7 indicates the lighting order itself when necessary segments are turned on according to the stroke order when displaying each number in the leftmost column.

FIG. 2 is a block diagram for explaining one embodiment of the driving method of the EC display device according to the present invention, in which each numerical display shown in the leftmost column of Table 1 is displayed on the EC display device according to the stroke order in the table. It is to be displayed. In Figure 2, keyboard 1
The numerical value inputted from the keyboard 1a is converted into a so-called B consisting of Bo-83 by an encoder circuit attached to the keyboard 1a.
CI) code and stored in register 2 for numeric values.

Table 1 At the same time, the keyboard 1a outputs a control signal K for resetting and current tossing the counter 3, and as a result, the counter 3 starts counting the clock pulses CL of the clock signal forming circuit 4. do.

FIG. 3 shows the elapsed time Tn (n=Q~7
) at the clock pulse CL and the output B4 of the counter 6
, B5, and B6, the counter 6 reset at To receives a 3-bit binary signal of B, , B, , B6 each time a clock pulse CL is input manually. Output the code to decoder 5,
T! Then (Be, B5, B4)=(1,,1
,■), and the count is stopped in that state. The register office also outputs to the decoder 5 a 4-bit BCI code Bo-B input manually from the keyboard 1a.

The decoder 5 receives the BCD code Bo-B from the register 2.
In order to display numbers corresponding to the contents of
It is output to the drive circuit 7 according to the above-mentioned stroke order at a timing synchronized with the change of 4 to B. In other words, the decoder 5 is EC
In order to display numbers on the display device B, the 0N-OFF states of the drive transistors corresponding to each segment/) a to g in the drive circuit 7 are sequentially changed so that writing is performed according to the above-mentioned stroke order. In order to control the switching signal Sa according to the above-mentioned stroke order.
-8g is output as a display signal.

Tables 2 and 3 illustrate the relationship between the keyboard 1a, the codes 84 to B6, and the switching signals Sa to Sg. Each write drive transistor in the drive circuit 7 applies or does not apply a write voltage of -E [V] when the potential of the counter electrode is referenced to the corresponding segment display electrode of the EC display device B. to control switching.

For example, when the display signal Sa is applied between the a segment display electrode and the write voltage, the write drive transistor corresponding to the segment a of the EC display device 6 drives the counter electrode 8 of the EC display device 60 between the a segment display electrode and the write voltage. ], when the display signal Sa is at logic level 1, the a segment is driven. Further, when a command corresponding to clearing the display is inputted from the keyboard 1a, the drive circuit 7 opens the connection between all the segment display electrodes and the write voltage -E [v], and also closes all the segment display electrodes. Erase the display by shorting it to ground potential.

As explained above, according to the EC display device of FIG. 2, in response to numerical input from the keyboard, the numbers can be written on the EC display device according to the order of strokes.

Next, FIG. 4 is a block diagram for explaining another embodiment of the driving method of the EC display device according to the present invention.
As in the case of the driving method of the EC display device of the embodiment, the display numbers shown in Table 1 are intended to be displayed on the EC display element according to the stroke order in the table.

Note that the drive circuit 7 and EC display device 6 in FIG.
They are similar to those in the first embodiment, and their explanation will be omitted. The numerical value entered using the keyboard 1b is B, as in the first embodiment described above. - It is converted into a BCIJ code consisting of B3 and input to the CPU 9. At the same time, in response to the start signal k from the keyboard 1b, the CPU 9 first selects the ROM 11 according to the manually inputted value.
The so-called cue is performed at 5 degrees, that is, ROM11.

It has 10 memory blocks corresponding to each number from ( ) to 9, and each block contains a 3-pit binary code M that changes sequentially in the order of the address and in accordance with the stroke order of each number. . . . M2 are arranged and stored.

Therefore, if the number 8 is entered manually, first the ROM
11, the address of the head of the block in which the stroke order data of the number 8 is stored is specified by the above-mentioned cueing. Furthermore, in synchronization with the clock pulse CL' from the clock signal forming circuit 10, the CPU 9 sequentially reads out the stroke order data arranged in address order following the above-mentioned first address, and further transmits this data to the interface 12. Output. The interface 12 converts the stroke order data sent one after another in synchronization with the clock pulse CL' into each display signal Sa-8g at a level suitable for the drive circuit 7 and outputs the same. As a result, the EC display device 6 is driven to write in accordance with the order of strokes, just as in the first embodiment described above.

As described above, in the present invention, when displaying numbers or characters by segments on an EC display device, writing is driven one segment at a time according to the stroke order.
Not only can instantaneous current consumption be reduced, but also it is possible to obtain a display with no density unevenness between display segments, that is, with uniform density. Furthermore, in the above embodiment, a case was explained in which numbers entered manually from the keyboard were displayed.
The present invention is also applicable to displaying time display data from a time setting circuit in an electronic timepiece or output data from a manual correction counter provided for time correction.

In addition, in electronic watches, when the display changes due to a change in the timekeeping contents, only the segments that have been in the display state and will be in the erased state are driven to erase, and the segments are then changed to the new display state. It may be configured such that writing is driven sequentially one segment at a time for each segment.

Furthermore, regarding the content of the display, the present invention is applicable not only to displaying numbers using seven segments, but also to displaying characters such as alphabets and Chinese characters.

As described above, the present invention pursues miniaturization by reducing power consumption of an EC display device using a battery power supply, equalizes display density between segments, and provides novelty to the visual sense when displaying and writing numbers and characters. Well, the effect is huge.

[Brief explanation of the drawing]

FIG. 1 is a pattern diagram showing a general Japanese character-shaped 7-segment numeric display pattern, FIG. 2 is a block diagram for explaining a driving method of an EC display device according to an embodiment of the present invention, and FIG. 3 is a time chart of FIG. 2, and FIG. 4 is a block diagram showing another embodiment of the present invention. 1a, 1b...Keyboard, 2...Register, 3...Counter, 4.10...
・Clock signal forming circuit, 5...Decoder, 6
... EC display device, 7 ... Drive circuit,
8...Counter electrode, 9...CP IJ,
11...R, OM. 12...Interface. Figure 3 TnTOTl D2 T3 T4 T5
T6 T7 Figure 4

Claims (1)

[Claims] (1,) In an electrochromic display device configured to display numbers, characters, etc. by a combination of a plurality of mutually independent segments, when displaying the numbers and characters, writing is driven one segment at a time in order. Characteristic driving method of electrochromic display device.