JPS5942288B2 - liquid crystal display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a liquid crystal display device that displays various patterns, and particularly to a liquid crystal display device that can increase the amount of information that can be displayed.

[Prior art]

In recent years, liquid crystal display devices have been widely used in devices such as calculators and watches because of their low power consumption.

In these devices, numbers are often displayed in seven segments, but other display patterns are becoming necessary as the amount of display information increases due to recent multifunctionalization. One of the technical means for liquid crystal display devices to solve this problem is a multilayer panel system. However, this method requires as many liquid crystal layers as the number of display patterns, and has drawbacks such as increased cost and increased thickness, making it less attractive as a product. Another method is a so-called multilayer electrode panel system in which transparent electrodes are formed on the inner surfaces of each of the 10 substrates sandwiching the liquid crystal layer, a transparent insulating layer is formed on top of the transparent electrodes, and a transparent electrode is further formed on top of the transparent electrodes. However, in this multilayer electrode panel system, the number of electrode terminals for connection with the outside and the 15 vertical conduction points are large, which limits the amount of display information and is not fully satisfactory. [Objective] It is an object of the present invention to use such multilayer electrode technology to increase the amount of displayed information, simplify the panel structure 20, and provide an inexpensive and compact liquid crystal display device.

[Summary of the invention]

In the liquid crystal display device of the present invention, in which a liquid crystal is sandwiched between two upper and lower substrates, a common electrode, an insulating layer, and a segment electrode are laminated on the inside of the two upper and lower substrates, respectively. The common electrodes of the two upper and lower substrates each include a plurality of electrodes, and a first display is made by the multiflex drive 30 by the common electrode of the upper substrate and the segment electrode of the lower substrate. A second display is made by multi-flex driving by the segment electrodes of the substrate and the common electrode of the lower substrate, and the common electrode of the portion where the common electrode of the upper substrate and the common electrode of the lower substrate face each other has a It is characterized in that 35 signals are applied to each of them.

[Embodiment] FIG. 1a shows a sectional view of an embodiment of the display structure of the present invention.

1 transparent substrate, 2 polarizing plate, 3, 4 lower transparent electrode, 5,
Upper transparent electrodes 5' and 6 (5' is used simultaneously with 5, so it is called a soil transparent electrode) 7 an insulating layer, 8 a liquid crystal layer, 9, 1
It consists of 0 changeover switches.

The upper transparent electrodes 5 and 6 are segment electrodes for segment display of independent patterns to be displayed.

The lower transparent electrodes 3 and 4 are common electrodes facing the segment electrodes, respectively.

When you want to display pattern 5, switch 9 is connected to the P system signal and switch 10 is connected to the d system signal as shown in the figure. Then, the entire set and area of the earth electrode 6 and the lower electrode 4 and the upper electrode 5 are displayed. The liquid crystals in the overlapping areas are driven and 5 patterns are displayed.

Conversely, when displaying pattern 6, switch 9 should be connected to the d-system signal, and switch 10 should be connected to the P-system signal. If you do not want to display either pattern 5 or 6, switch 9 or 10.
All you have to do is connect it to the d-system signal.

Further, it is controlled by the 0N, 0FF and P system signals displayed in the pattern 5'. To connect the liquid crystal display to an external circuit, first connect the upper electrode 6 and lower electrode 4 on the lower substrate side to the upper substrate side through the soil and lower conductive material, provide electrode terminals on the soil substrate, and then It is connected to the external circuit with conductive rubber along with the electrode terminal on the board side.

Therefore, the number of upper and lower conductive members is the number of segments of the upper electrode 6 + the number of common electrodes of the lower electrode 4.

As is well known, the liquid crystal drive system includes a static drive system and a multiflex drive system. If the static drive method is used, the number of display images of the upper electrode 6 + one line of the lower electrode 4 is required for the upper and lower conductive points. 3. However, in the case of the multiflex 1 driving method, there is an advantage that the number of display pixel lead lines can be reduced when driving many display pixels.

Specifically, in the case of the two-digit multiflex driving method, the number of upper electrodes 6 is 1/2 of the number of display pixels, and the number of lower electrodes 4 is two. In the case of the 33-digit multiflex drive system, the upper electrode 6
The number of display pixels is 1/3, and the number of lower electrodes 4 is three.

That is, as the number of display pixels increases, the number of upper and lower conductive points can be reduced by increasing the number of driving digits. FIG. 1b shows the basic signal of the drive waveform of the 2-digit multiflex 1 drive system 4. The voltage value is 0 and the battery voltage V. and part 2
A double value of 2V0 is required. The lower electrodes 3 and 4 have Dl and d2
The signals of P, 2, PO, P are distributed to the upper electrodes 5 and 6.
l, P2 according to the displayed content 4'. selectively apply.

Here, P and 2 are signals that turn on in response to both common signals d1 and D2, and PO is a signal that does not turn on in response to any of the common signals D1 and d2. and,
Pl and P2 are signals that turn on only in response to common signals Dl and d2, respectively. At this time, the effective voltage value in the 0N state is V72. VO, and the effective voltage value in the 0FF state is ▼]
Huh V. becomes. In the case of the present invention, since the lower electrodes 3 and 4 are opposed to each other with the liquid crystal in between, when a voltage difference occurs, the liquid crystal between them is driven by one.

For example, if different signals d1 and D2 are applied to opposing electrodes, the effective voltage will be: becomes. this is,
The effective voltage value is between ON (5 and OFF), resulting in a halftone phenomenon. Therefore, it is necessary to give the same signal to the opposing electrodes in the lower electrodes 3 and 4. When displaying, strictly speaking, the effective voltage value applied to the liquid crystal differs between the portion where electrodes 4 and 6 overlap and the case where electrode 4 does not overlap.

This is because voltage is directly applied to the liquid crystal by electrodes 5 and 6 in the part where electrodes 4 and 6 overlap, whereas voltage is applied directly to the liquid crystal by electrode 4 in the part where electrode 4 does not overlap with electrode 6. 4
This is because a voltage is applied to the liquid crystal due to and 5. However, even when voltage is applied to the liquid crystal via the insulating layer by electrodes 4 and 5, this voltage is 80% of the part to which voltage is directly applied by electrodes 5 and 6 by setting the insulating layer to about 7000 to 8000λ. Since a certain voltage can be secured, this does not pose a practical problem. In this way, by configuring the upper and lower electrodes via an insulating layer, displaying two different patterns on a single layer of liquid crystal panel, and driving this multiplexed, it is possible to reduce the number of upper and lower conductive points. .

Examples will be given and explained below. [Application example] Next, an example in which the present invention is applied to a calendar display will be described.

By applying the present invention to a liquid crystal display device that displays a calendar for January or more, one of the left and right columns always shows Sunday, and all seven days of the week can be displayed. Figure 2 A, b, c, and d show the electrodes of this application example, which have a two-digit multi-flex electrode configuration, with the pixel portions indicated by thick or diagonal lines, and the extraction electrode portions. It is indicated by a thin line.

Figure 2a shows the upper electrodes of the upper substrate, 5 and 5' in Figure 1a.
It corresponds to S, and includes 11 segment electrodes, each with S
EGl, SEG2・・・・・・・・・・・・・・・SE
It is abbreviated as Gll. Figure 2b shows the lower electrode of the lower substrate;
It corresponds to 4 in FIG. 1a and includes two common electrodes, which are abbreviated as COM1 and COM2, respectively. The overlapping portion of both electrodes represents a display pattern. FIG. 2c shows the upper electrode of the lower substrate, which corresponds to 6 in FIG.
It is abbreviated as EGlV. Figure 2 d is the lower electrode of the upper substrate, which corresponds to 3 in Figure 1 a, and has one common electrode, which is CO
It is abbreviated as MV. The overlapping portion of these two poles represents a display pattern. That is, in this application example, four types of day table patterns are provided, two types each on the upper and lower boards, and two types of date display patterns are provided, 5 rows and 9 columns and 6 rows and 10 columns. By combining them as appropriate, you can light up the lights so that Sunday is always located at the far left. Next, a specific signal selection method will be described.

However, the following explanation is just one example, and equivalent results can be obtained by appropriately replacing the subscripts (1, 2) of the signal name, for example. As mentioned above, when the common electrodes face each other on the upper and lower substrates, it is necessary to input the same signal, so C
OMl, COMV is Dl in Figure 1 b, COM2 is D
2 signal is applied.

Next, the segment electrodes will be described. The major months where Sunday starts on the 1st are SEGlV, 4', 5', σ, 7', 8
',9' is P1 or Pl2, SEG8,9 is P.
, P2 is applied to SEG7, and 0FFd1 is applied to ON and other segment electrodes. Here SEGlf, 4′
, 5, 6', γ, 8', and 9' can be either P1 or Pl2 because the common electrode corresponding to these segment electrodes is only COM1 and does not have COM2. If the moon is small, set SEGq to P. Or you can change it to P2, and in February, SEG7' and 8' should be changed to P2. Or just change to P2. In the case of a leap year, P1 or Pl2 may be applied to SEGγ. Next, the major month whose Sunday starts on the 2nd is P in SEGlO', 1, 2, 3, and 4.
1 or Pl2, Pl for SEG8, Pl for SEG9
2. P for SEG7.

, d1 may be applied to other segment electrodes.
In the case of a small moon, just change SEG9 to P, and 2
In the case of the moon, set SEG8 and 9 to P. You can change it to . In the case of a leap year, SEG8 should be changed to P1. The major months where Sunday starts on the 3rd are SEGll, 2, 3, 4
, P1 or Pl2 in 5, Pl2 in SEG8, SEG9
P2 may be applied to the segment electrodes, and d1 may be applied to the other segment electrodes. In the case of small months, February, and leap years, the signal can be changed using the method described above, so the description will be omitted here. The major month whose Sunday starts on the 4th is SEGlO, 3
, P1 or Pl2 for 4, 5, 6, Pl2 for SEG8,
Pl to SEG7, P to SEG9. , and D to the other segment electrodes. Major months whose Sunday starts on the 5th are SEGlO', V, 7, 3X, 4'
, γ, 8', 9'' are P1 or Pl2, SEG7, 8
, 9 has P. , d1 may be applied to other segment electrodes. The big month where Sunday starts on the 6th is SEGl
P1 or Pl2 for l, 7, 3', 4', 5', 7', 81, 9', P for SEG7, 8, 9. , d1 may be applied to other segments. Major months with Sunday starting on the 7th are SEGlO, 3', 4', 5', Ff, 7
',8',q is P1 or P,2, SEG7,8,9
P. , and other segments. With the above combination, it is possible to display the calendar for all months. In the case of this application example, the rightmost row of the date display pattern displayed on the upper electrode on the upper substrate side is normally displayed as the date display pattern on the upper electrode on the lower substrate, but this is changed to the upper electrode on the upper substrate side. By moving it, the number of vertical conduction points is reduced.

This is multiplied and driven to reduce the number of three display pixel lead lines, so-called electrode terminals. This effect is significant in today's world where the amount of displayed information is increasing due to multifunctionality. One thing to keep in mind when drawing a pattern is that when the lead-out portion of each upper electrode overlaps the opposing electrode, it lights up, but such overlapping portions must be crossed at a portion that cannot be seen from the outside.

If this is not possible, the thickness of one of the intersecting lead wires should be set to 3/100 WI or less, and one or more wires may be connected, so that even if the light is turned on, it will not be visible to the naked eye, and there will be no problem in terms of appearance. FIGS. 4A, b, c, d, e, f, and g show specific calendar displays according to this application example.
All months have 31 days. As you can see from the diagram, even though the layout has changed slightly, Sunday is always on the left edge and all seven days of the week are displayed, making the calendar display easy to read. In the above embodiments and application examples, the present invention was explained using a two-digit multi-flex drive, but if a 1 drive voltage margin for the liquid crystal can be secured, the same concept can be applied to a multi-digit multi-flex drive such as three digits or four digits. can.

[Effects] As described above, according to the present invention, the electrodes are arranged in two layers on the upper and lower electrode substrates with an insulating layer interposed between them, and the common electrode on the upper substrate and the common electrode on the lower substrate are opposed to each other. By applying the same signal to these common electrodes, it is possible to drive the liquid crystal in multi-flex mode without generating halftones, which increases the amount of displayed information and greatly reduces the number of vertical conductions within the liquid crystal panel. This makes it possible to easily manufacture a liquid crystal display device with a multilayer electrode structure and to reduce costs.

Furthermore, since the number of upper and lower conductors can be significantly reduced, the display area of a liquid crystal panel of the same size can be increased.

[Brief explanation of the drawing]

Fig. 1a...A sectional view of the display structure of the present invention, Fig. 1b...Diagram of driving waveforms, Fig. 2a-d...
. . . Electrode pattern of calendar display according to the embodiment of the present invention, Figures 3 a-g . . . Examples of calendar display according to the embodiment of the present invention.

Claims (1)

[Claims] 1. In a liquid crystal display device in which a liquid crystal is sandwiched between two upper and lower substrates, a common electrode, an insulating layer, and a segment electrode are laminated and provided on the inside of each of the upper and lower two substrates, and At least one of the common electrodes is constituted by a plurality of electrodes, a first display is performed by multiplex driving by the common electrode of the upper substrate and the segment electrode of the lower substrate, and the segment electrode of the upper substrate A second display is made by multiplex driving by the common electrode of the lower substrate and the common electrode of the upper substrate and the common electrode of the lower substrate are connected in common, respectively. A liquid crystal display device characterized in that the same signal is applied.