JPH0456919A - Liquid crystal display element - Google Patents

Abstract

PURPOSE:To improve the display quality by arranging transparent electrodes of transparent substrates up to outside transparent electrodes in a display area and driving them while the color tone of a non-display area at the periphery of the display area is matched with that of a display image. CONSTITUTION:The transparent electrodes of both the transparent substrates 1 are arranged up to outside the transparent electrodes 2x and 2y in the display area 7, and driven. Therefore, when the electrodes are driven, for example, while the display image 9 is not selected, the color tone of, for example, the non-display area 8 can be matched with that of the display image 9 by driving the electrodes so that the transparent electrodes in the non-display area 8 are not selected. The color tones of the display area 7 and non-display area 8 can be matched similarly even at the time of a reverse voltage selection. Consequently, the display quality can be improved.

Description

[Detailed Description of the Invention] [Summary] With regard to liquid crystal display elements, an object of the present invention is to improve display quality by making the color tone of a non-display area on a screen the same as the color tone of a displayed image in a display area. Two transparent substrates on which live transparent electrodes and alignment films are sequentially formed are arranged with a spacer in between so that the transparent electrodes are perpendicular to each other, and liquid crystal is injected and sealed into the gap-like space formed between the two transparent substrates. A liquid crystal display element comprising at least a fixed liquid crystal display panel, a polarizing plate disposed on both sides of the liquid crystal display panel, and a retardation film disposed on at least one side of the liquid crystal display panel. The liquid crystal display element is configured such that the transparent electrodes of each substrate are arranged outside the transparent electrodes in the display area, and the color tone of the non-display area around the display area is driven in accordance with that of the displayed image.

[Industrial application field]

The present invention relates to an electrode structure for improving the display quality of a liquid crystal display element, particularly a retardation film type STN type liquid crystal display element (FSTN type liquid crystal display element).

In recent years, the development of display devices has been remarkable, and in particular, flat displays have rapidly become popular due to their thinness and light weight. Among them, liquid crystal display devices have a low driving voltage and are inexpensive, so they are being actively introduced into the field of office automation equipment such as personal computers and word processors.

Recently, black-and-white liquid crystal display elements using double cells and retardation films have been developed, and the scope of their use is expanding further.As a result, there is a demand for further improvements in display quality such as ease of viewing on the screen. It is being

[Conventional technology]

Liquid crystal display elements that are currently widely used use a liquid crystal material that is a mixture of nematic liquid crystal and a small amount of cholesteric liquid crystal. So-called T N (Twisted
Nematic) type or S T N (Super
It is of the Th1sted Nematic type, that is, the Nematic type. In particular, STN type liquid crystal display devices are increasingly being used to increase contrast. In general, contrast is improved in STN type liquid crystal display elements, but as a result of utilizing the birefringence effect, the background color becomes yellowish-green or purple, which may be disliked by users.

What is the most preferred monochrome display device?

Normally, the display is black and white, and there has been a demand for a liquid crystal display device that can display black and white. Recently, methods to solve this problem have been proposed and are beginning to be put into practical use. In both of these, a compensation plate is placed on the liquid crystal display panel to compensate for the wavelength dispersion of the phase difference of incident light that occurs in the liquid crystal layer.
For example, typical examples include a two-layer liquid crystal system (double cell system - DSTN system) that uses a compensation liquid crystal panel, and a plastic film with refractive index anisotropy (for example,
A retardation film method using a polycarbonate film (so-called FSTN method) is known.

Figure 3 is a diagram showing an example of the electrode configuration of a conventional liquid crystal display element.
This is shown for the case of the retardation film method.
The same figure (a) is a top view (with the fixed frame partially removed), and the same figure (b) is a top view (with the fixed frame partially removed).
is a ^-A sectional view.

In the figure, 1 is a transparent substrate, for example, a glass substrate, 2x,
2y was formed on two transparent substrates 1. For example, a striped transparent electrode made of ITO (Inz03-SnOz), 3 is an adhesive layer for sealingly bonding the peripheral edges of two transparent substrates 10, and the transparent electrodes 2x and 2y face each other and They are sealed in an orthogonal arrangement to form a Y matrix intersection.

Note that an alignment film is applied on the transparent electrodes 2x and 2y, for example, by coating a polyimide resin film and then brushing it with a nylon brush for alignment treatment, and a predetermined gap-like space is formed between the two substrates. A spacer, for example, a small ball made of polyester resin, is inserted to form a spacer, but these are omitted to avoid complication of the drawing.

4. Liquid crystal in the gap-like space between the above two substrates. for example,
5TN(Super Twisted Nea+ati
If c) type liquid crystal is injected and sealed, an STN type liquid crystal display panel is formed.

On both sides of the liquid crystal display panel, a polarizing plate 5 and a retardation film 6 are arranged at a predetermined azimuth angle, and the periphery of these laminates is fixed with a fixing frame 10 to form a liquid crystal display element. . Note that the retardation film 6 does not necessarily need to be placed on both sides, and may be placed only on one side as long as it has the function to achieve the purpose.

Now, for example, if light is applied from the lower side of the liquid crystal display element and a signal voltage is applied to the transparent electrode 2y and a scanning voltage to the transparent electrode 2X from a drive power source (not shown) to the knee, the picture electrode can be changed. Light switching is performed depending on whether or not a voltage is applied at the intersections of the χ-Y matrix. In other words, each intersection constitutes a pixel, and for example, as shown in FIG. Is displayed.

[Problem to be Solved by the Invention] Generally, in a liquid crystal display device, the front end 1 of the fixed frame 10
1 is shifted outward from the display area 7 by about 5 to 10 mm. That is, the display element screen is wider than the display area 7. This is to prevent the display image 9 at the end of the display area 7 from being obscured by the 1° thickness of the fixed frame.

However, in the conventional liquid crystal display element described above, the transparent electrodes 2x and 2y are not formed in the non-display area 8 around the outer periphery of the display area 7, as shown in FIG.

In the case of the simple matrix method, as is well known, for example, even when the display image 9 is not selected, a voltage is applied to some parts of the display image 9 due to the unidirectional pattern, so there is a non-display area 8 where no voltage is applied at all. The color tone is different from that of the original, giving the user a sense of discomfort and, in some cases, making it difficult to work for long periods of time. On the other hand, if you try to force both color tones to match, display quality problems arise such as reduced contrast and hue deterioration.
A solution was needed.

[Means to solve the problem]

The above problem was solved by arranging two transparent substrates 1 on which striped transparent electrodes 2 and alignment films were sequentially formed, with a spacer in between so that the transparent electrodes 2 were perpendicular to each other, and forming a layer between the two transparent substrates 10. A liquid crystal display panel in which a liquid crystal 4 is injected and sealed into a gap-like space, a polarizing plate 5 disposed on both sides of the liquid crystal display panel, and a retardation film 6 disposed on at least one side of the liquid crystal display panel. In the liquid crystal display element, the transparent electrodes 2 of each of the transparent substrates 1 are disposed to the outside of the transparent electrodes 2x and 2y in the display area 7, and the color tone of the non-display area 8 around the display area 7 is adjusted. This can be solved by a liquid crystal display element that is driven to match that of the displayed image 9.

[Effect]

The liquid crystal display element of the present invention is arranged so that the transparent electrodes 2 of each of the transparent substrates 1 are arranged outside the transparent electrodes 2x and 2y in the display area 7 and driven, so that, for example, the displayed image 9 When driven with no selection, the non-display area 8
By driving the transparent electrode 2 so that it is also non-selected, it becomes possible, for example, to match the color tone of the non-display area 8 to that of the displayed image 9. Of course, it is clear that the color tones of the display area 7 and non-display area 8 can be matched in the same manner even in the case of reverse voltage selection.

〔Example〕

FIG. 1 is a diagram showing an embodiment of the present invention; FIG. 1A is a top view (with a fixed frame partially removed), and FIG. 1B is a cross-sectional view taken along line A-A.

In the figure, 2x and 2y are formed on two transparent substrates 1 and arranged orthogonally to form a display area 7. For example, I.T.
O (Inz03 5nOz), for example, 64
It is a striped transparent electrode of 0 x 400 lines.

On the other hand, 2x'' and 2y゛ are the transparent electrodes 2 x + 2
The same stripe-shaped transparent electrodes are arranged continuously to the outside of each y and are formed at the same pitch with the same electrode width. good.

In this example, the gap-like space, that is, the cell thickness = 6
μm, twist angle=260° (7) A FSTN type liquid crystal display element was constructed.

Note that the same reference numerals are given to the same parts as those explained in the drawings of the conventional example, and the explanation of the same parts will be omitted.

In this embodiment, the transparent electrode 2 formed in the non-display area 8
Since a voltage can be applied to x'+2y' in the same way as the transparent electrodes 2x and 2y for the display image in the display area 7, for example, the color tone of the non-display area 80 can be applied to the display image 9.
It is extremely easy to adjust the display performance to that of , and the display performance is improved without giving any discomfort to the user.

The voltage can be applied to each of the transparent electrodes 2x' and 2yl.

Alternatively, several lines may be applied at once.

FIG. 2 is a diagram showing another embodiment of the present invention, in which (a) is a top view (with the fixed frame partially removed), and (b) is a sectional view taken along line 8-^.

In the figure, 2x and 2y are formed on two transparent substrates 1 and arranged orthogonally to form a display area 7. For example, ITo
(In2o3 5nOz), for example, 640
This is a striped transparent electrode with 400 lines.

On the other hand, 2x'' and 2y'' are predetermined spaces outside the transparent electrodes 2x and 2y, for example, the transparent electrode 2x.

One or several wide transparent electrodes are formed with the same space as the 2y space, and the width and number of electrodes may be formed to be sufficient to fill the non-display area 8. FIG. 2 shows the case of one wire for convenience.

In this embodiment, since there is no need to make the widths of the transparent electrodes 2X'' and 2V'' very narrow, there is an advantage that problems such as a decrease in manufacturing yield do not occur.

In each of the above embodiments, the retardation film 6 is shown arranged on both sides of the liquid crystal display panel, but the retardation film 6 may be arranged only on one side as long as it functions to achieve the purpose. This is as already stated.

The embodiments described above are merely examples, and it goes without saying that preferred materials and configurations, or combinations thereof may be used as appropriate, as long as they comply with the spirit of the present invention.

〔Effect of the invention〕

As explained above, according to the present invention, the transparent electrodes 2 (2x', 2y' or 2X"2y
”) are arranged and driven to the outside of the transparent electrodes 2x and 2y in the display area 7, so for example, when the display image 9 is not selected and is driven, the non-display area 8 Transparent electrode 2 (2x', 2y' or 2x''
+2y'') is also deselected.

For example, it is now possible to match the color tone of the non-display area 8 to that of the display image 9, which contributes to improving the performance and quality of FSTN liquid crystal display devices without deteriorating the display hue or contrast. Extremely large.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing another embodiment of the present invention, and FIG. 3 is a diagram showing an example of the electrode configuration of a conventional liquid crystal display element. In the figure, 1 is a transparent substrate, 2 (2x+2y+2x', 2y'+ 2x', 2y")
3 is a transparent electrode, 3 is an adhesive layer, 4 is a liquid crystal, 5 is a polarizing plate, 6 is a retardation film, 7 is a display area, 8 is a non-display area, and 10 is a fixed frame. (a) L side Figure 2-built aFi electric &

Claims (1)

[Claims] Two transparent substrates (1) on which striped transparent electrodes (2) and alignment films are sequentially formed are arranged with a spacer in between so that the transparent electrodes (2) are perpendicular to each other, and both transparent A liquid crystal display panel in which liquid crystal (4) is injected and sealed into a gap-like space formed between substrates (1), polarizing plates (5) disposed on both sides of the liquid crystal display panel, and the liquid crystal display panel. A liquid crystal display element comprising at least a retardation film (6) disposed on at least one side of the transparent electrode (2) of each transparent substrate (1) in a display area (7). , 2y), and is driven to match the color tone of a non-display area (8) around the display area (7) to that of a display image (9).