JPS60112021A - Liquid-crystal display body device - Google Patents

Abstract

PURPOSE:To obtain a color liquid-crystal panel of high display quality at a low cost by mounting a filter substrate where a red, green, and blue (RGB) pattern corresponding to respective picture elements is formed on one thin plate glass substrate of the liquid-crystal panel. CONSTITUTION:A color filter 14 formed on a glass substrate surface where the RGB pattern is formed is placed on the thin plate glass substrate 13 having a common electrode 5 formed over the entire surface. Liquid crystal 7 is charged between this substrate 13 and a transparent substrate 1 provided with liquid- crystal driving electrodes 4 to form the panel, and a polarizing plate 15 is arranged on both surfaces of the panel. The plate thickness of the thin plate glass substrate 13 is smaller than the pitch of respective picture elements, i.e. driving electrodes 4. Thus, the filter layer is formed at a low cost without bringing the RGB pattern into contact with the liquid crystal 7, an insulating layer is formed of SiO2, etc., on the electrode 5 to stabilize unidirectional orientation, and the substrate 5 is made thin to shorten the distance between the liquid-crystal layer 7 and filter layer 14, obtaining a high-quality display while the parallax is reduced.

Description

[Detailed description of the invention] Technical fields> Unexploded lyJ relates to liquid crystal display devices.

Furthermore, the present invention relates to a liquid crystal display panel capable of color display. A feature of the present invention is that a color liquid crystal panel with high display quality and advantageous in cost can be realized.

<Conventional Example> In general, liquid crystal display devices can be driven at low voltage and low power, and have recently been put into practical use in many consumer devices as bright and easy-to-read displays. For example, applications that take advantage of the advantages of liquid crystal display devices, such as wristwatches, calculators, and automobile dashboards and dashboard panels, are expected to grow significantly in the future. In addition, in recent years, liquid crystal televisions have begun to attract attention, using an active matrix substrate as one substrate of the liquid crystal panel, and displaying images by selecting signals using switching elements arranged in each pixel. Compared to conventional CRT TVs, LCD TVs can be made smaller and thinner, and consume less power, making them ideal for portable TVs. is also possible. Furthermore, in the case of a liquid crystal display, full color display is possible by placing a color filter substrate on the liquid crystal panel. FIG. 1 shows a cross-sectional structural diagram of a conventional full-color liquid crystal display device. 1 in the figure is, for example, TII'T
4 is a TPT substrate on which is fabricated, and 4 is a liquid crystal drive electrode connected to the drain electrode side of the TFT.

2 is a glass substrate on the surface of which a color filter layer 6 is formed. 6 is a spacer that controls the cap of the liquid crystal panel. 5 is a counter electrode formed on the color filter layer 6. 7 is a liquid crystal layer. In the liquid crystal display device shown in FIG. 1, as is clear from the figure, a counter electrode is formed on the surface of the color filter layer B. Liquid crystal panels require a process to orient liquid crystal molecules in a certain direction, and the most common method is a rubbing method. This method involves rubbing the surface of the substrate with absorbent cotton, dry cloth, or the like. According to this method, since the color filter layer 6 shown in the figure is made of, for example, a gelatin layer and is soft, it may attract stains, which poses a problem in terms of appearance.

Further, since the surface of the color filter layer 6 is uneven, sufficient alignment cannot be achieved, resulting in a problem of poor liquid crystal display characteristics.

Furthermore, since the color filter layer 6 and the liquid crystal layer 7 are in contact with each other via the opposing electrodes, there is a high possibility that dirt in the color filter layer 6 will diffuse into the liquid crystal, lowering the liquid crystal resistance and causing a decrease in contrast. .

<Purpose of the Invention> The present invention was invented to solve the road defects of the conventional color liquid crystal display, and not only can the above-mentioned problems be solved, but also the cost can be further reduced, and the cost performance can be improved. This enables high-quality color liquid crystal displays.

<Example> FIG. 2 shows an example of a pixel pattern on an active matrix substrate used in the present invention.

The active matrix substrate is a MOS on a silicon substrate.
) There are two types: one in which a transistor array is built in, and the other in which a TPT (thin film transistor) array is formed on a transparent substrate. When considered as a liquid crystal display, the former is a DS
Suitable for M (dynamic scattering mode) and GH (guest host) type display, the latter is 'I' in addition to DSM and GH.
Suitable for N (twisted nematic) mode display.

FIG. 2 is an example of a pixel pattern formed on a transparent substrate, and one pixel area is indicated by α and b in the figure. In the figure, 8 is a timing signal line, 9 is a data signal line, and the area near 10 is a TPT (thin film transistor) portion. 11 is a liquid crystal drive electrode made of a transparent conductive film. 12 is a contact hole. The data signal line and the liquid crystal drive electrode are formed of a To (indium tin oxide) film. In this way, the 'rll'T active matrix is usually formed on a glass substrate. The sizes of α and b vary depending on the size of the display device, but for example, when considering a liquid crystal TV for botples, it is 0.1 to 0-
It will be about 3 mm.

FIG. 3 shows a cross-sectional structural diagram of a liquid crystal display device according to the present invention using the active matrix substrate shown in FIG. 1.3, 4, and 5.7 in the figure correspond to the numbers shown in FIG. 16 is a thin plate glass made of unexploded 1'lJ. A transparent electrode 5 is formed on the entire surface in contact with the liquid crystal layer 7 made of thin film glass. The thickness of thin film glass is shown in Figure 2 α
It is desirable that the pixel pitch be smaller than the pixel pitch shown in and b. In the embodiment of the present invention, the pixel pitch α=140μ
Normally, b: 170 μm, and therefore, a glass plate with a thickness of 100 μm was used as the thin glass. Thin glass can also be obtained by polishing, but for example, one commercially available from Corning Co. under the trade name Microsheet may be used.

14 in the figure is a color filter plate, and 15 is a polarizing plate. The feature of the present invention shown in FIG.
j). By making the thickness of the thin glass thinner than the pixel pitch, the distance between the liquid crystal layer and the color filter layer was made as short as possible, and parallax was minimized.

As a result, when the viewing angle was set to 90° in the vertical direction of the panel, and the 6 o'clock feed of the panel was set to 0°, good images were obtained at angles of 60° to 100°.The characteristics of this example are as follows. Unlike the conventional panel shown in Figure 1, since the thin glass itself can be rubbed, the orientation is stable and high-quality images can be obtained. Furthermore, since an insulating film can be formed on the transparent electrode of thin glass, it is possible to sufficiently block the direct current flowing through the liquid crystal layer, which is unique to the TPT active matrix. (In the conventional panel shown in Figure 1, since the color filter layer is a soft organic film, it is difficult to form an insulating film on the color filter layer, so it has to be formed on the TNT substrate side, and the insulating film is formed on the TTT substrate side.) If formed,
Since the surface of the TPT substrate is highly uneven, it has been difficult to form an insulating film with high insulation resistance. ) The insulating film may be made of 5i02 or the like, and its thickness may be approximately 1000 to 3000X. 16 in the figure is an insulating film.

FIG. 4 shows the types of color filter substrates used in the present invention. FIG. 4 (α) shows that after forming a dyeable layer of gelatin, acrylic, or PVA (polyvinyl alcohol) to a thickness of about 1 to 3 μm on a glass substrate 17, R, G, and B are dyed through a photo-etching process. A three primary color pattern 18 is formed. The feature of this color filter substrate is that the dyeable layer is dyed with dye.
The hue of each of R, G, and B is highly accurate. A protective film is formed on this color filter layer, and a transparent conductive layer V: is formed thereon by sputtering. FIG. 4(b) shows a color filter substrate produced by printing. In this method, a transparent resin mixed with dye or pigment is screen printed or offset printed on the glass substrate 19. 20 in the figure is an offset printed pattern. The feature of this color filter is that it is low cost because it uses a printing method to form R, G, B patterns. In FIG. 4(c), a color film is used. This is a reversal film commonly used for color slides and the like, and is obtained by exposing and developing a film in which several to ten layers of dyes (three primary colors) are formed on a polyester base, for example. Since this color film filter is a plastic film, it deforms slightly due to temperature and humidity, but it can be exposed to light three times.

Since a color film is obtained in the developing process, it can be manufactured at a lower cost and is the most promising method.

FIG. 5 shows another embodiment according to the invention. 1 in the diagram.
3, 4, 5, 7.13 correspond to the numbers in FIGS. 1 and 6. 23 in the figure is a color filter substrate. '
I'FT active matrix substrate has T for each pixel.
Ii'T is formed, and the number of pixels is, for example, 220.
In the case of X240, the number is 52,800. It is very important to make all these TPTs from good quality products.
<, There are inevitably some pixel defects. In a transmissive panel using a backlight, a white pixel defect is more noticeable to the human eye than a black pixel defect.

The present embodiment is characterized in that, as shown at 24 and 25 in the figure, the pixel defects are made inconspicuous by filling in the white pixel defects with black paint.

For the black paint to be pasted, it is appropriate to use black paint with high adhesiveness and high strength.

FIG. 6 is a diagram in which a color filter film or a color filter substrate is placed in contact with a panel made up of a TPT substrate 1 and a thin glass plate. 6th
Figure (α) shows a color filter on a thin glass plate! To: board 2
FIG. 6 is a diagram in which the parts 6 and 6 are bonded together with an adhesive 26. The thickness of the adhesive is preferably 1 to 50 microns or less. This method is flexible in the case of color filter films, so
If J&N agent is printed on one side of a strawberry glass plate or a color filter film, and the two are pasted together, they can be pasted together neatly without any air bubbles. However, when the color filter substrate is a glass plate, it is better to place adhesive only at the four corners or the periphery of the color filter substrate for bonding, as shown in No. 66(h).

As explained in the many embodiments above, the present invention provides a liquid crystal display device in which an active matrix substrate is used as one substrate constituting a liquid crystal panel and a thin glass substrate is used as the other substrate, and on the thin glass substrate, This invention relates to a liquid crystal display device characterized in that a color filter substrate on which an RGB pattern corresponding to each pixel is formed is brought into contact with the liquid crystal panel, and then polarizing plates are arranged on the top and bottom of the liquid crystal panel. The following effects can be expected compared to body devices.

(1) The alignment of the liquid crystal panel is extremely stabilized.

(2) Since the DC current cutting insulating film of the liquid crystal panel can be formed on a thin glass plate at tV, it is possible to form a stable film with better characteristics than when forming on an IFT substrate.

(3) Since the color filter layer is not in direct contact with the liquid crystal layer through the ITo layer, it is necessary to reduce impurities (alkali metal ions, etc.) in the color filter layer, and There is no need to perform flattening, etc., and the color filter can be obtained at a lower cost than conventional color filters.

The present invention is very effective not only as a display for a small portable liquid crystal television, but also as a portable display for the future information society, such as a monitor for a video camera, a terminal display for a portable computer, and the like.

Brief description of drawings] Figure 1 is a cross-sectional row 1 of a conventional color liquid crystal video display panel. Drawing. FIG. 2 is a pattern diagram on a TPT substrate used in a liquid crystal display panel according to the present invention.

Figure 3, 4th DC(L)e (b), (c), 51st Δ
, FIG. 6(α), Ch) are sectional views and explanatory diagrams illustrating the type of liquid crystal panel and force 2-filter according to the present invention.

1... TPT substrate 2... Color filter substrate 3... Sealant 4... Liquid crystal drive electrode 5 on TPT substrate...
... Common electrode 6 ... Color filter layer 7 ... Liquid crystal (TN) 8 ... Timing line 9 ... Data line 10 River TFT 11 ... Liquid crystal drive electrode 12...contact hole 13...thin glass plate 14...color filter 15...polarizing plate 16...Do cut (direct current cutoff) film 17...glass substrate 1B... Color filter layer 19...Glass substrate 20...Color filter layer 21...Film 22...Color filter layer 26...Color filter substrate 24...Black ink 25...Black ink 26... ·glue

Claims (2)

[Claims] (1) In a liquid crystal display device in which an active matrix substrate is used as one substrate of the liquid crystal panel and a thin glass plate is used as the other substrate, an RGB pattern corresponding to each pixel is formed on the thin glass plate. 1. A liquid crystal display device characterized in that polarizing plates are placed above and below a liquid crystal panel after the color filter substrates are brought into contact with each other. (2) The liquid crystal display device according to claim 1, wherein the thickness of the thin glass plate is smaller than the pixel pitch.