JPH09244015A - Liquid crystal display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deterioration in display quality due to visible driving circuits around a display part in a liquid crystal display panel in which driving circuits are formed on one of transparent substrates, by forming a light-shielding film which prevents direct visibility of at least the driving circuits. SOLUTION: A light-shielding film 16 is formed, for example, by selective etching of photolithographic techniques or printing, on the peripheral part of the surface of a TFT substrate 10 which faces the observer. Namely, the light- shielding film 16 is formed to optically expose only a display region 11 which is substantially a display part. The light-shielding film 16 of this method may be a metal layer such as chromium which cuts light, or a resin film containing a black pigment may be used. Since the light-shielding film 16 is formed in this liquid crystal display panel, direct visibility of vertical scanning circuits 12 and image driving circuits 13 can be prevented by the light shielding film 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display panel, and more particularly to a liquid crystal viewed from a transparent substrate surface on either side, in which liquid crystal sealed with a sealing material is interposed between transparent substrates facing each other. The present invention relates to a liquid crystal display panel in which a drive circuit provided in the sealing region and close to the sealing material is formed on one surface of the transparent substrate.

[0002]

2. Description of the Related Art In a liquid crystal display panel having a built-in drive circuit as described above, a semiconductor layer forming a thin film transistor provided for each pixel in a so-called display region is formed of polycrystalline silicon (polysilicon). Seen in.

That is, each of the pixels arranged in a matrix has the thin film transistor turned on by the scanning signal from the gate signal line and the pixel to which the video signal from the drain signal line is supplied via the turned on thin film transistor. It is composed of an electrode (transparent electrode).

The drive circuit is composed of a set of complementary MIS transistors, and each of these MIS transistors
Since the type transistor is formed in parallel with the manufacturing of the thin film transistor, its semiconductor layer is also made of polycrystalline silicon.

Therefore, such a liquid crystal display panel is
By observation from the display section side, a display area that substantially functions as a display section in a frame-shaped sealing material that encloses liquid crystal, and a drive circuit formation area formed between the display area and the sealing material. (However, this is formed in an extremely narrow range).

On the other hand, a liquid crystal display panel of this type is usually small and is used by being incorporated in a projection type liquid crystal display device or a head mounted liquid crystal display device.

[0007]

However, when the liquid crystal display panel thus constructed is used by being incorporated in a projection type liquid crystal display device, its image is enlarged and projected on the screen. Will be.

When the head mounted liquid crystal display device is incorporated and used, the image is largely projected in front of the eyes.

Therefore, the observer can observe not only the display section in which the pixels are arranged in a matrix but also the driving circuits around the display section, which is annoying. It was pointed out that it would be extremely unpleasant to the person.

The present invention has been made under such circumstances, and an object of the present invention is to provide a liquid crystal display panel in which the display quality is prevented from being visually deteriorated by a drive circuit around the display section. .

[0011]

In order to achieve such an object, according to the present invention, basically, a liquid crystal sealed with a sealing material is interposed between transparent substrates facing each other. In the liquid crystal display panel in which the drive circuit provided in the liquid crystal sealing region viewed from the transparent substrate surface on the side of and adjacent to the sealing material is formed on any one surface of the transparent substrate, It is characterized in that a light-shielding film that prevents direct visual observation of the drive circuit is formed.

The liquid crystal display panel having the above structure is
Since the light shielding film is formed on the panel itself,
This light-shielding film can prevent direct visual observation of the drive circuit.

In this case, the light-shielding film serves as a boundary with the display area because it must cover the driving circuit completely without actually extending over the display area which is the display section. It is necessary to accurately position the surrounding area.

Therefore, the above requirement can be achieved by forming the light shielding film on the panel itself by selective etching or printing using a photolithographic technique.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a liquid crystal display panel according to the present invention will be described below with reference to the drawings.

Embodiment 1 FIG . 1A and 1B are configuration diagrams showing an embodiment of a liquid crystal display panel according to the present invention, in which FIG. 1A is a plan view and FIG. 1B is a sectional view taken along line bb of FIG.

In FIG. 1, first, there are transparent substrates arranged to face each other with a liquid crystal interposed therebetween. Among these, the transparent substrate positioned on the upper side in the figure is a so-called TFT substrate 10, and the transparent substrate positioned on the lower side is so-called. It is the filter substrate 20.

The TFT substrate 10 is provided with a display region 11 which substantially serves as a display portion in the central portion excluding its periphery.

The TFT substrate 10 in this display area 11
Although not shown in the drawing, the gate signal lines extending in the x direction and juxtaposed in the y direction, and the surfaces extending in the y direction insulated from these gate signal lines Drain signal lines arranged in parallel in the direction are formed, and respective regions surrounded by the respective signal lines are pixel regions.

The respective pixel regions are arranged in a matrix, and the pixel regions arranged in the matrix form a display region.

In each of these pixel regions, a thin film transistor turned on by a scanning signal from the gate signal line and a pixel electrode (transparent electrode) to which a video signal from the drain signal line is applied via the turned on thin film transistor. ) And are formed.

Here, in the thin film transistor, its semiconductor is formed of polycrystalline silicon (polysilicon).

A vertical scanning circuit 12 extending along the side (y direction) is formed on the left side of the display area 11, for example, in the drawing, and the vertical scanning circuit 12 is formed on each gate signal line. The scanning signals are sequentially supplied from.

The image drive circuit 1 extending along the side (x direction) of the display area 11, for example, on the upper side in the figure.
3 is formed, and the video signal is supplied from the video drive circuit 13 to each of the drain signal lines in synchronization with the scanning signal supply timing.

Here, both the vertical scanning circuit 12 and the video driving circuit 13 are composed of a set of complementary MIS type transistors, and the semiconductor of each of these transistors is made of polycrystalline silicon. It is formed in parallel with the formation of the thin film transistor.

Then, each input terminal to the vertical scanning circuit 12 and the video driving circuit 13 is connected to T via a wiring layer (not shown).
For example, it extends to the lower side of the FT substrate 11, and is drawn out as the connection terminal group 14 at this side portion.

The filter substrate 20 arranged so as to face the TFT substrate 10 has substantially the same size as the TFT substrate 10, but exposes the connection terminal group 14 formed on the TFT substrate 10. It is formed to be small.

On the liquid crystal side surface of the filter substrate 20,
A common electrode (transparent electrode) common to each pixel region, a color filter, and a black matrix are formed.

The common electrode is drawn out to one connection terminal of the connection terminal group 14 on the TFT substrate 10 side. In this case, the filter substrate 2
The four corners of 0 are drawn out through the conductor provided between the TFT substrate 10 and the four corners.

The liquid crystal interposed between the TFT substrate 10 and the filter substrate 20 described above is sealed by a seal material 15 provided in a frame shape between the substrates.

The frame-shaped sealing material 15 is provided in the display area 11
Of course, the vertical scanning circuit 12 and the video drive circuit 13 formed around the display area 11 are also formed so as to surround them.

As described above, the vertical scanning circuit 12 and the image driving circuit 13 are arranged inside the seal material 15.
For example, due to the following reasons.

Since the liquid crystal display panel of this type has a small pixel area, a spacer made of fine particles for ensuring a uniform gap between the TFT substrate 10 and the filter substrate 20 is mixed only in the sealing material 15. The liquid crystal is not mixed in at all. And the sealing material 15
Since the curing of is performed by pressure bonding through each substrate,
This is for avoiding damage to the ultra-fine signal line arranged under the sealing material 15 due to this pressure bonding.

In the liquid crystal display panel thus constructed, the TFT substrate 10 side is the side on which the viewer observes, and the backlight 30 is arranged on the filter substrate 20 side.

In this way, on the surface of the TFT substrate 10 on the side viewed by the observer, the light shielding film 16 is formed around the surface of the TFT substrate 10 by selective etching or printing using the photolithographic technique, for example. That is, the light-shielding film 19 serves as the display area 1 which is substantially a display portion.
It is formed so that only 1 is optically exposed.

In this case, the light shielding film 16 may be a metal layer such as chromium that shields light, or may be a resin film containing a black pigment, for example.
Needless to say, it may be formed by attaching an opaque adhesive tape.

The liquid crystal display panel having the above structure is
Since the light shielding film 16 is formed, the vertical scanning circuit 12 and the image driving circuit 13 are formed by the light shielding film 16.
It is possible to prevent the direct visual observation of.

In this case, the light-shielding film 16 must completely cover the vertical scanning circuit 12 and the video drive circuit 13 without particularly extending to the display area 11 which is substantially a display section. It is necessary to accurately position the periphery that is the boundary with the display area 11.

Therefore, the above requirement can be achieved by forming the light-shielding film on the panel itself by selective etching or printing using a photolithographic technique.

In FIG. 1 (b), the surface of the filter substrate 20 on the side of the backlight 30 and the TF.
On the observer side surface of the T substrate 10, the polarizing plate 2 is provided.
0a and 10a are formed.

In the above-mentioned embodiment, the light shielding film 16 is formed so as to expose only the display area 11, but the invention is not limited to this, and at least the vertical scanning circuit 12 and the video driving circuit 13 are provided. It is needless to say that the same effect can be obtained even if it is formed so as to cover.

Example 2. FIG. 2 is a sectional view showing another embodiment of the liquid crystal display panel according to the present invention.

In the figure, the TFT substrate 10 is positioned on the backlight 30 side (therefore, the filter substrate 20 is on the observer side), and the black matrix 17 made of Al (aluminum) is on the TFT substrate 10 side. It has a formed structure.

In this case, the black matrix 17 is usually formed so as to also cover the vertical scanning circuit 12 and the video drive circuit 13, but the black matrix 17 covering these circuits is observed through the filter substrate 20. Since it is visible to a person, the light-shielding film 16 formed on the filter substrate 20 prevents the visual observation.

The visual observation of the black matrix 17 itself does not cause any particular problem, but since it is made of Al, it is intended to prevent the reflected light due to external light from disturbing the observer. It is a thing.

Also in this case, the light shielding film 16 may be formed so as to expose only the display region 11.
Further, it goes without saying that it may be formed so as to cover only the formation region of the drive circuit (vertical scanning circuit 12 and video drive circuit 13).

[0047]

As is apparent from the above description,
According to the liquid crystal display panel of the present invention, it is possible to prevent the visual quality of the drive circuit around the display unit from being visually deteriorated.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a liquid crystal display panel according to the present invention.

FIG. 2 is a configuration diagram showing another embodiment of the liquid crystal display panel according to the present invention.

[Explanation of symbols]

10 ... TFT substrate, 20 ... Filter substrate, 11 ...
Display area, 12 ... Vertical scanning circuit, 13 ... Image driving circuit, 16 ... Shading film.

Claims (4)

[Claims] 1. A liquid crystal sealed with a sealing material is interposed between transparent substrates facing each other, and is close to the sealing material in a liquid crystal sealing region viewed from the surface of the transparent substrate on either side. In a liquid crystal display panel in which a drive circuit provided on one side of the transparent substrate is provided, at least a light-shielding film that prevents direct visual observation of the drive circuit is formed. . 2. The driving circuit is formed on a liquid crystal side surface of a transparent substrate on which an observer observes, and a black matrix is formed on a liquid crystal side surface of another transparent substrate. 2. The liquid crystal display panel according to claim 1, wherein at least a light-shielding film for obstructing the direct visual observation of the drive circuit is formed on the surface of the transparent substrate on which the observer observes. 3. The drive circuit and a black matrix made of Al covering the drive circuit on the liquid crystal side surface of another transparent substrate different from the transparent substrate viewed by an observer. 2. The liquid crystal display panel according to claim 1, wherein a light-shielding film that obstructs direct visual observation of the black matrix in at least the drive circuit formation region is formed on the surface of the transparent substrate on the side viewed by an observer. 4. The liquid crystal display panel according to claim 1, wherein the light shielding film is formed by selective etching or printing using a photolithographic technique.