JPH0125069B2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a liquid crystal display device.

BACKGROUND ART Recently, two-layer type liquid crystal display devices have been commercialized, which include two upper and lower liquid crystal display layers and which display two types of display by switching between the two display layers.

However, this two-layer liquid crystal display device has only one
Although one display device can display the same amount of information as two display devices, it has the disadvantage that it is quite thick because its structure is essentially a stack of two liquid crystal display cells. .

In order to solve these drawbacks, the
A liquid crystal display device using a two-layer electrode substrate as disclosed in No. 108418 has been proposed. In this liquid crystal display device, two layers of electrodes are provided on each of the inner surfaces of a pair of opposing substrates with an insulating layer interposed therebetween, and the upper layer electrode is formed with a window corresponding to the display pattern formed by the lower layer electrode. A segment signal is supplied to the lower layer electrode of the substrate, the upper layer and lower layer electrode of the other substrate and the upper layer electrode of one substrate are set at the same potential, and a voltage higher than the threshold voltage with respect to the potential of the segment electrode is applied to the liquid crystal. A signal having a potential such as that applied to the display is supplied, and thereby a plurality of patterns can be displayed.

However, the above-mentioned liquid crystal display device has a large number of terminals and is difficult to display a complex pattern with a large number of segment electrodes because one terminal is connected to one segment electrode and the device is statically driven. It was hot.

The present invention has been made in view of the above-mentioned circumstances, and its object is to provide a liquid crystal display device equipped with a two-layer electrode substrate, in which an electrode for static drive and an electrode for dynamic drive are connected to two electrodes. It is an object of the present invention to provide a liquid crystal display device which can reduce the number of terminals by arranging them in layers and can display a large number of patterns with a large number of segment electrodes.

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 1 and 2 are a pair of upper and lower transparent substrates (for example, glass plates);
The substrates 2 are adhesively polymerized via a frame-shaped sealing material 3, and the gap between the two substrates 1 and 2 is filled with liquid crystal (not shown). 4, 4 are both the substrates 1,
2, for example, the inner surface (lower surface) of the upper substrate 1
The static driving segment electrodes 4, 4 are formed in a pattern as shown in FIG. 2, for example. 5 is a transparent insulating layer that covers the static driving segment electrodes 4, 4 formed on the inner surface of the upper substrate 1 and their leads 4a, 4a; 6, 7 are a plurality of transparent insulating layers formed on the surface of the insulating layer 5; This is a common electrode for dynamic driving, and the common electrodes 6 and 7 for dynamic driving have a pattern as shown in FIG. 2, for example. Note that this embodiment shows one driven at 1/2 duty. Further, the dynamic drive common electrodes 6, 7 are formed excluding the portions that overlap with the effective areas of the respective static drive segment electrodes 4, 4. In this embodiment, the dynamic drive common electrodes 6, 7 are are formed to be slightly larger than the actual display pattern, and the dynamic drive common electrodes 6, 7 have cutout portions 6a, which are shaped to match the outline of the actual display pattern, in the portions overlapping with the static drive segment electrodes 4, 4. 7a. In other words, the dynamic drive common electrodes 6, 7
are the static drive segment electrodes 4,
It also serves as a shielding electrode that defines the effective area of the static drive segment electrodes 4 and 4.
If a shielding signal having a potential difference lower than the threshold voltage of the liquid crystal with respect to the potential of the static common signal is applied to the dynamic driving common electrodes 6 and 7 when the static segment signal is applied to the static driving segment electrode 4,
4 is larger than the actual display pattern, the portion corresponding to the actual display pattern for the liquid crystal (the missing portion 6 of the common electrodes 6 and 7 for dynamic driving)
A voltage higher than the threshold voltage acts only on the portions corresponding to a and 7a). That is, the effective area of the static driving segment electrodes 4 corresponds to the actual display pattern. In this embodiment, the static drive segment electrodes 4, 4 are made larger than the actual display pattern because of the missing portions 6 formed in the dynamic drive common electrodes 6, 7.
This is to facilitate positioning of the electrodes a and 7a with respect to the static drive segment electrodes 4 and 4.

On the other hand, 8, 8 is the other substrate, that is, the lower substrate 2
A plurality of groups of dynamic drive segment electrodes are formed on the inner surface (upper surface) of the dynamic drive segment electrodes 8, 8, which have a pattern as shown in FIG. 3, for example. In addition,
These segment electrodes 8, 8 for dynamic driving are made into one group and are commonly connected for each group, and the common electrodes 6, 7 for dynamic driving formed on the upper substrate 1 are connected to one of the common electrodes. 6 is formed to face one segment electrode 8 of each group, and the other common electrode 7 is formed to face the other segment electrode 8 of each group. 9 is a transparent insulating layer that covers the dynamic drive segment electrodes 8, 8 formed on the inner surface of the lower electrode substrate 2 and their leads 8a, 8a; 10 is a static drive segment electrode formed on the surface of the insulating layer 9; This static drive common electrode 10 is a common electrode, and as shown in FIG. 3, the static drive common electrode 10 is formed except for the portion that overlaps with the effective area (portion corresponding to the actual display pattern) of each of the dynamic drive segment electrodes 8, 8. has been done.
Reference numerals 10a and 10a are missing portions having a shape that matches the outline of the actual display pattern (display pattern by dynamic drive) formed on the static drive common electrode 10. In this embodiment, the dynamic drive segment electrodes 8, 8 are also formed slightly larger than the actual display pattern.
The missing portions 10a, 10a formed in the static drive common electrode 10 can be easily aligned with the dynamic drive segment electrodes 8, 8, so that the static drive common electrode 10 also has the same position as the dynamic drive segment electrodes 8, 8. It also serves as a shielding electrode that defines the effective area of the dynamic drive segment electrodes 8, 8. Note that each of the electrodes 4,
6, 7, 8, and 10 are all made of a transparent electrode material such as indium oxide. Furthermore, in this embodiment, the static drive segment electrodes 4, 4 and the dynamic drive segment electrodes 8, 8 are formed directly on the substrates 1, 2; A transparent insulating layer may be formed on the transparent insulating layer, and if it is necessary to further form a liquid crystal alignment film, this alignment film may be used as the dynamic drive common electrode 6,
7 and the common electrode 10 for static driving.

Further, of the static drive segment electrodes 4, 4, those located at positions facing the dynamic drive segment electrodes 8, 8 are the missing portions 6 of the dynamic drive common electrodes 6, 7.
The dynamic drive common electrodes 6, 7 and the static drive segment electrodes 4, 4 form the dynamic drive segment electrodes 8, 8.
A complete common electrode is now formed for each. This also applies to the common electrodes for the static drive segment electrodes 4, 4, and the dynamic drive segment electrodes 8, 8 are connected to the static drive common electrode 1.
By using a common electrode to compensate for the missing portion 10a of 0, the static drive segment electrode 4,
A complete common electrode for 4 is now formed.

In addition, in FIGS. 1 and 2, 1a, 1a
are terminal array parts formed on both sides of the upper substrate 1, and these terminal array parts 1a, 1a have static driving segment electrodes 4, 4 formed on the upper substrate 1 as shown in FIG. Terminals 4b, 4b
Terminals 6b, 7b of each common electrode 6, 7 for dynamic driving are formed by leading out, and segment electrodes 8, 7b for dynamic driving of each group on the lower substrate 2 side are arranged side by side with these terminals 4b, 6b, 7b.
Terminals 8b, 8b and 10b corresponding to the static drive common electrode 10 are formed. Further, in FIG. 3, 8c, 8c and 10c are terminals of the dynamic drive segment electrodes 8, 8 and the static drive common electrode 10 of each group formed on the lower substrate 2, and these terminals 8c, 8c and 10c are respectively are connected to the respective terminals 8b, 8b, and 10b on the upper substrate 1 side via transfer members (not shown) that penetrate the sealing material 3.

Next, the display operation of the liquid crystal display device of this example will be explained.

This liquid crystal display device performs two types of display: display by static drive and display by dynamic drive. First, the display operation by static drive will be explained. In this case, the static drive common electrode 10 formed on the lower substrate 2 and all the dynamic drive segments located at positions facing the static drive segment electrodes 4, 4. The same static common signal is commonly applied to the electrodes 8, 8, static segment signals are applied to the static drive segment electrodes 4, 4 formed on the upper substrate 1, and all dynamic drive A shielding signal having a potential difference smaller than the threshold voltage of the liquid crystal with respect to the static common signal is applied to the common electrodes 6 and 7. Note that this shielding signal may be at the same potential as the static common signal, but if the potential difference between the static segment signal and the shielding signal is large, the difference between the static drive segment electrodes 4, 4 and the dynamic drive common electrodes 6, 7 Since a large-capacity capacitor is formed in the signal line, power loss increases, so it is desirable that the shielding signal has a potential difference of about 1/2 of the threshold voltage with respect to the static common signal. Therefore, the static drive common electrode 10 and its missing portions 10a, 10a
When a static common signal is applied to the dynamic drive segment electrodes 8, 8 which complement the static drive segment electrodes 4, 8, they all work as common electrodes for the static drive segment electrodes 4, 4, and thereby the static segment A display pattern corresponding to the shape of the static drive segment electrodes 4, 4 to which the signal is applied is displayed. Further, in this case, since the shielding signal as described above is applied to the dynamic drive common electrodes 6 and 7, unnecessary portions of the static drive segment electrodes 4 and 4 (the dynamic drive common electrodes 6 and 7 The electric field between the leads 4a, 4a and the lower substrate 2 is canceled by the dynamic driving common electrodes 6, 7, so that the pattern actually displayed is The pattern corresponds to the shape of the effective display area of the static drive segment electrodes 4, 4.

In addition, when displaying by dynamic drive, dynamic common signals whose phases are shifted by 180 degrees from each other are applied to the dynamic drive common electrodes 6 and 7 formed on the upper substrate 1, and one dynamic drive The same common signal as the common signal applied to one of the dynamic drive common electrodes 6 is applied to the static drive segment electrodes 4, 4 that compensate for the missing parts 6a, 6a of the common electrode 6, and the same common signal is applied to the other dynamic drive common electrode 6. The same common signal as that applied to the other dynamic drive common electrode 7 is applied to the static drive segment electrodes 4, 4 that compensate for the missing portions 7a, 7a of the common electrode 7. Note that the application of the dynamic common signal to the static drive segment electrodes 4, 4 only needs to be applied to the electrodes 4, 4 located at positions facing the dynamic drive segment electrodes 8, 8. On the other hand, a dynamic segment signal is applied to the dynamic drive segment electrodes 8, 8 formed on the lower substrate 2, and the liquid crystal threshold voltage is applied to the static drive common electrode 10 with respect to the dynamic common signal. A shielding signal with a smaller potential difference (preferably a potential difference of about 1/2 of the threshold voltage) is applied. Therefore, in the case of dynamic drive, the common electrodes 6, 7 for dynamic drive and the segment electrodes 4, 4 for static drive that compensate for the missing parts 6a, 7a act as common electrodes for the segment electrodes 8, 8 for dynamic drive. As a result, a display pattern corresponding to the shape of the dynamic driving segment electrodes 8, 8 to which the dynamic segment signal is applied is displayed. Also in this case, since the potential shielding signal as described above is applied to the static drive common electrode 10, unnecessary parts of the dynamic drive segment electrodes 8, 8 (overlapping with the static drive common electrode 10) are ) and the electric field between the leads 8a, 8a and the upper substrate 1 is the static drive common electrode 1.
Therefore, the pattern actually displayed will be a pattern corresponding to the shape of the effective area of the dynamic drive segment electrodes 8, 8.

That is, in principle, the liquid crystal display device of this embodiment has a plurality of static driving segment electrodes 4, 4 and a plurality of static drive segment electrodes 4, 4 on the inner surface of one substrate 1 of a pair of substrates 1, 2 which are arranged opposite to each other with a liquid crystal interposed therebetween. Common electrodes 6 and 7 for dynamic driving are formed on the inner surface of the other substrate 2, and a plurality of groups of segment electrodes 8 and 8 for dynamic driving and a common electrode 10 for static driving are formed on the inner surface of the other substrate 2, so that static driving can be performed in one display layer. Two types of display are performed: one by dynamic drive and the other by dynamic drive. In the liquid crystal display device of this embodiment, the dynamic drive common electrode 6,
7 and common electrode 10 for static drive are respectively used as shielding electrodes that cover unnecessary parts of segment electrodes 4, 4 for static drive and segment electrodes 8, 8 for dynamic drive, and these common electrodes 6, 7, and 10 are used as shielding electrodes for each of the segments. The common electrodes 6, 7 and 1 are formed except for the parts that overlap with the effective areas of the electrodes 4, 4 and 8, 8.
Since the missing portions 6a, 7a and 10a of 0 are compensated for by using the segment electrodes 4, 4 and 8, 8 as common electrodes, the display by static drive is also replaced by dynamic drive. The display is also complete, with no unnecessary displays such as lead shapes, and without any chipping in the pattern.

In the above embodiment, the static drive segment electrodes 4, 4 and the dynamic drive segment electrodes 8, 8 are formed slightly larger than the actual display pattern; The same shape as the actual display pattern may be used, and the entire area may be used as an effective area.
The edges of 10a and 10a may be aligned. Further, in the above embodiment, the drive unit is driven at 1/2 duty during dynamic drive, but this is not limited to drive at 1/2 duty.

Note that this liquid crystal display device may be of a twisted nematic type, a guest-host type, or any other type.

As described above, in this invention, each of the plurality of common electrodes for dynamic driving has a missing portion in a portion corresponding to the entire display pattern formed by the segment electrode for static driving in the lower layer.
Since the display pattern formed by one segment electrode for static drive does not overlap with a plurality of common electrodes for dynamic drive, the electrode for static drive and the electrode for dynamic drive can be divided into two.
A layered electrode structure can be formed, and a large number of complex patterns can be displayed and driven with a small number of terminals.

[Brief explanation of drawings]

The drawings show one embodiment of the invention.
The figure is a longitudinal side view, FIG. 2 is a bottom view of the upper substrate, and FIG. 3 is a plan view of the lower substrate. DESCRIPTION OF SYMBOLS 1... Upper substrate, 2... Lower substrate, 3... Seal material, 4... Segment electrode for static drive, 5... Insulating layer, 6, 7... Common electrode for dynamic drive, 8... For dynamic drive Segment electrode, 9... Insulating layer, 10... Common electrode for static drive.

Claims (1)

[Claims] 1. Of a pair of substrates placed opposite to each other with a liquid crystal in between, a plurality of static drive segment electrodes and a plurality of dynamic drive common electrodes are stacked on the inner surface of one substrate with an insulating film interposed therebetween, and A plurality of segment electrodes for dynamic drive and a common electrode for static drive are sequentially laminated on the inner surface of the substrate with an insulating film interposed therebetween. A missing portion is formed in a portion corresponding to the entire display pattern formed by the segment electrodes, and a missing portion is formed in the static driving common electrode in a portion corresponding to the display pattern formed by the dynamic driving segment electrode. A liquid crystal display device.