JP3130802B2 - Liquid crystal display - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid crystal display device, and more particularly to an active matrix type liquid crystal display device using thin film transistors (hereinafter, referred to as TFTs).

[0002]

2. Description of the Related Art In a liquid crystal display device, a liquid crystal is sandwiched between two electrodes, an electric field is applied between the two electrodes to drive the liquid crystal, and display is performed on a liquid crystal panel. An active matrix type liquid crystal display device which retains the charged electric charge until the next frame has been developed.

With reference to FIG. 6, a general configuration of an active matrix type liquid crystal display device will be described. FIG.
As shown in (a) and (b), the active matrix type liquid crystal display device includes a liquid crystal panel 102 and a light source 306.
And a driving circuit 402. As shown in FIG. 6A, the liquid crystal panel 102 includes a display unit 106,
It is composed of a lead wiring section 103 and a terminal block 104. As shown in FIG. 6B, the light source 306 includes the fluorescent tube 101, the reflector 107, and the light guide plate 110.

FIG. 7A is an enlarged view of a portion II in FIG. 6A, and FIG. 7B is a sectional view taken along the line hh 'in FIG. 7A. As shown in FIG. 7A, terminals 109 for applying a voltage to the liquid crystal panel 102 are provided in a strip shape in the terminal block 104 of FIG.
Display unit 106 of the liquid crystal panel 102 (a) and the terminal 109
6A, a plurality of lead wirings 108 are provided in the lead wiring part 103 of FIG. 6A.

FIG. 8 is a sectional view taken along the line dd 'of FIG. On the TFT side glass substrate 301, transparent pixel electrodes 303 are formed in a matrix, and the opposite side glass substrate 3
On 08, a transparent counter electrode 302 is formed.

[0006] The peripheral portions of the TFT side glass substrate 301 and the opposite side glass substrate 308 are bonded together with a seal 304, and a liquid crystal 305 is sealed between the substrates 301 and 308.
A TFT-side polarizing plate 307 is provided under the FT-side glass substrate 301.
However, the opposing polarizing plate 309 is attached on the opposing glass substrate 308, and the liquid crystal panel 102 is completed.

The light emitted from the fluorescent tube 101 of the light source 306 is reflected by the reflector 107 toward the light guide slope 110, and the light is emitted from the light guide slope 110 to the liquid crystal panel 102. The liquid crystal panel 102 has an outer peripheral portion, that is, the electrode 30.
2,303 and outside covered by the shield 701 than a region not covered by the seal de 701 display unit 10
It functions as zero.

FIG. 9 is a sectional view taken along line ee ′ of FIG. The transparent pixel electrode 303 is connected to a terminal 109 via a lead wiring 108, and the terminal 109 is connected to a TCP 401 on which a driving driver is mounted.

Next, the operation of the liquid crystal display device will be described. As shown in FIG. 6, the display unit 1 in the liquid crystal panel 102
At 06, an electric signal from the driving circuit 402 is applied with a voltage via the TCP 401 equipped with a driving driver.
As shown in FIG. 8, the counter electrode 3 of the liquid crystal panel display unit 106
02 and the transparent pixel electrode 303, the potential difference between the counter electrode 302 and the pixel electrode 303 causes the liquid crystal 3.
An electric field acts on 05. At this time, the light transmittance of the liquid crystal panel 102 changes depending on the electric characteristics of the liquid crystal 305 and the characteristics of the polarizing plates 307 and 309. That is, the light source 306
The amount of light transmitted from the liquid crystal panel 102 is controlled by an electric signal from the driving circuit 402.

[0010]

In order to achieve the above object, a liquid crystal display device according to the present invention is a liquid crystal display device having a pair of substrates, a liquid crystal, and a light-shielding pattern,
One substrate of the pair is disposed a matrix on the transparent pixel electrode on a glass substrate, which has a lead-out wiring portion and the terminal block is provided for applying a voltage to the transparent pixel electrodes, the drawer Wiring section and terminal block
The lock has a light-shielding property, the other substrate forming a pair has a counter electrode formed on a glass substrate, and the liquid crystal is sealed between the paired substrates.
The light-shielding pattern is formed of a conductor layer different from a lead provided in the lead-out wiring part and a terminal provided in the terminal block. The light-shielding pattern is formed between lead-out wirings in the lead-out wiring part and between the terminal blocks. It blocks light passing between the blocks.

For this reason, the display unit 106 shown in FIG.
At the outer edge ff ′ of the light-emitting device causes uneven brightness due to the light leakage. In particular, a larger amount of light leaks to the display screen in the vicinity between the terminal blocks 104 where there is no light-shielding portion than in the vicinity of the lead-out wiring portion 103 where the light-shielding portion is dense.

FIG. 5B shows a display unit 10 according to a conventional example.
6 shows a light amount distribution leaking from the vicinity of No. 6; f1 to f6 are shown in FIG.
Corresponds to each position of the outer edge ff ′.

As a known example of the measure for improving the luminance unevenness, a method of coloring the seal 304 of FIGS. 8 and 9 black and shielding light (Japanese Unexamined Patent Publication No. Hei 7-13171) is known. A method of forming a light-shielding film so as to cover a portion where 304 is formed (Japanese Patent Laid-Open No. 5-224196).
There is.

However, the seal 30 of FIGS.
In the method in which 4 is colored black to block light, the light blocking effect is as follows.
The light is limited to light incident on the seal 304. In a method in which a light-shielding film is formed on the opposing glass substrate 308 so as to cover the portion where the seal 304 is formed, the TFT glass substrate 301
There is a problem that it is not possible to block light leaking to the display unit 106 by transmitting the light through the shield 701 and the opposite glass substrate 308.

An object of the present invention is to provide an active matrix type liquid crystal display device in which the brightness variation at the outer edge of the display portion near the light source installation portion of the liquid crystal display device is improved without adding any special process or material. It is to provide a device.

[0016]

In order to achieve the above object, a liquid crystal display device according to the present invention is a liquid crystal display device having a pair of substrates, a liquid crystal, and a light-shielding pattern,
One of the substrates forming a pair has transparent pixel electrodes arranged in a matrix on a glass substrate, and has a lead wiring portion and a terminal block provided for applying a voltage to the transparent pixel electrode. The other substrate to be formed is a substrate in which a counter electrode is formed on a glass substrate, the liquid crystal is sealed between the paired substrates, and the light-shielding pattern is a wiring provided in the wiring wiring portion. It is made of a conductor layer different from the terminals provided in the terminal blocks, and is formed between the lead wirings and between the terminal blocks, and blocks light passing between the lead wirings and between the terminal blocks.

Further, the lead-out wiring, the terminal and the light-shielding pattern are formed by a conductor layer of a thin-film transistor constituting a liquid crystal display device.

[0018]

According to the present invention, as shown in FIG.
Ray 601 obliquely penetrates into the glass substrate 301 and the shield 701 that passes through the glass substrate 301 on the TFT side and the glass substrate 3 on the opposite side.
08 and leaked light 601 that enters the display unit 106
The light-shielding pattern 10 provided between the terminal 109 and the lead-out wiring 108 and the terminal 109 and the lead-out wiring 108
5 does not leak to the display unit 106 side.
For this reason, the position variation of the amount of light leaked to the display section at the section cc ′ in FIG. 1 is reduced and improved as compared with the conventional example.

[0019]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1A is a plan view showing an embodiment of the present invention, and FIG. 1B is a side view thereof.

As shown in the drawing, the liquid crystal display device according to the present invention comprises a liquid crystal panel 102, a light source 306, and a driving circuit 4.
02.

The liquid crystal panel 102 includes a display section 106, a lead wiring section 103, and a driving circuit 402. The display section 106 of the liquid crystal panel 102 has an opposite glass substrate 308 and a TFT glass substrate 301 that are vertically stacked.

On the TFT side glass substrate 301, a TFT side polarizing plate 307 is formed on the back side, and transparent pixel electrodes 304 are formed in a matrix on the front side. On the opposite side glass substrate 308, an opposite transparent electrode 302 is formed on the back side, and an opposite side polarizing plate 309 is formed on the front side.

The outer edge side is sealed by a seal 304 between the lath substrate 308 and the TFT-side glass substrate 301 on the opposite side, and a liquid crystal 305 is sealed in the gap.

The peripheral side of the liquid crystal panel 102 is covered with a shield 701, and the shield 701 defines a display section 106 capable of displaying an image. On the outer edge side of the liquid crystal panel 102 covered by the shield 701, a lead wiring portion 103 and a terminal block 104 are provided.

As shown in FIGS. 2A and 2B, the lead wiring portion 103 is provided with a plurality of lead wires 108, and the terminal block 104 is provided with a plurality of terminals 109 connected to each lead wire 108. Is provided. There is a gap between the lead wirings 108 and between the terminal blocks 104, and there is room for the light rays 601 from the light source 306 to pass therethrough.

Therefore, according to the present invention, as shown in FIG. 2A and FIG.
A light-shielding pattern 105 made of a conductive layer is provided between the four light-shielding layers 4, and the light-shielding pattern 105 shields leaked light. Further, the light-shielding pattern 105 is formed by the lead-out wiring 1.
08 and the terminal 109 are made of a different conductor layer, and the lead-out wiring 108 and the terminal 109 and the light-shielding pattern 105 are
It is formed of a conductor layer of a thin film transistor constituting a liquid crystal display device. The area A between the adjacent terminals 109 and the area B where the terminal block 104 and the TCP 401 are connected
Since the light is shielded by the CP 401 or the like, the light shielding pattern 10
There is no need to provide 5.

Next, a manufacturing process for forming a conductive layer and a wiring of a TFT according to the present invention will be described with reference to FIG.

FIG. 4 (a) shows the T used for the liquid crystal panel.
It is sectional drawing which shows an example of FT structure. The TFT includes a drain electrode 503, a source electrode 502, a gate electrode 501, an insulating layer 504, and an a ^- Si layer 50.
5, together with the n ⁺ a ^- Si layer 506, constitute a MOS transistor. The transparent pixel electrode 303 is connected to the source electrode 502, and a voltage is applied to the transparent pixel electrode 303 by the operation of the MOS transistor. Each of the above patterns is protected by the passivation layer 507.

Hereinafter, the formation of the TFT of the display unit 106 and the wiring of the peripheral part will be described in order. First, FIG.
As shown in (b), a Cr sputtered film 1400 # is formed on the glass substrate 301, and the gate electrode 501 and the light-shielding pattern 105 are formed by photolithography and etching.

Next, a sputtered film 1000 of SiO ₂ and a P ^- CVD film 4000 of Si ₃ N ₄ are formed.
04 is patterned. Next, an a ^- Si P ^- CVD film 3000 ^# , an n ⁺ a ^- si P ^- CVD film 500 ^# are formed, and an a ^- Si layer pattern 505 and an n ⁺ a ^- Si layer pattern 506 are formed. Then, a contact hole for electrical connection with an electrode is formed in the insulating layer 504.

Next, as shown in FIG. 4C, a sputtered Cr film 1400 # is formed, and the drain electrode 503, the source electrode 502, the lead wiring 108, and the terminal 109 are patterned. Next, the n ⁺ a ^- Si film 505 between the drain electrode 503 and the source electrode 502 is removed by dry etching.

Next, an ITO sputtered film 400 # is formed, and the transparent pixel electrode 303 is patterned. Finally S
P of i ₃ N ₄ ^- the CVD film 6000Å was deposited to form a passivation layer 507, further, to form a contact hole for electrical connection with the electrode by a photolithography technique. As described above, the formation of the TFT of the display portion and the wiring of the peripheral portion is completed.

In the above description, the lead wiring 108 and the terminal 109 are formed of the same conductor layer as the drain electrode 503 and the source electrode 502.
Are formed of the same conductor layer as the gate electrode 501, the light-shielding pattern 105 is formed by the drain electrode 503 and the source electrode 5
The same effect can be obtained by forming with the same conductor layer as 02.

According to the present invention, the light-shielding pattern 105 is formed as shown in FIG.
As shown in (b), the insulating layer 504 is inserted and the lead wiring 108 and the terminal 109 are formed of a different conductor layer. For this reason, the space reference between the light shielding patterns 105 caused by the short circuit between the light shielding patterns 105 can be reduced from 30 μm or more in the same plane to 5 μm or more. Here, the width of the terminal 109 and the lead wiring 108 is about 40 to 7
0μ.

When the light-shielding pattern 105 is provided on the entire surface, if a defect occurs in the insulating layer 504, the light-shielding pattern 1
Cane between lead wiring through 05 10 8 - DOO occurs, resulting capacitive coupling with lead wiring 108 each other via the light-shielding pattern 105, because caused the problems such as disturbance of the display screen is generated, it is unsuitable.

Next, the operation of the embodiment of the present invention will be described.
This will be described with reference to the drawings. In the structure of the present invention, the light beam 601 transmitted through the TFT-side glass substrate 301 from the light source in FIG.
As shown in (b), the light is reflected by the lead wiring 108 / terminal 109 and the light shielding pattern 105. Therefore, by adding the light-shielding pattern 105, the amount of light leaked from the space between the terminal 109 and the lead-out wiring 108 can be greatly reduced. This effect is particularly noticeable in the additional portion of the light-shielding pattern 105 between the TCPs 401 in FIG.

As described above, the light-shielding pattern 105 shown in FIGS. 2A and 2B is formed of a wiring layer different from the lead wiring 108 and the terminal 109 by inserting the insulating layer 504, thereby obtaining the light source shown in FIG. The leakage light amount of the light beam 106 that enters the display unit 106 from the display unit 306 can be reduced, and the position variation of the leakage light amount to the display unit at the cc ′ section in FIG. 1A is greatly improved as compared with the conventional example. You. FIG. 5 (a) shows the variation in brightness in the section of FIG. 1c-c '. In FIG. 5A, c
1 to c6 correspond to the respective portions in FIG.

As described above, the light shielding pattern 105
Is the same as TF
When a conductor layer of T is formed (the conductor layer requires two layers of a drain electrode / source electrode and a gate electrode), it can be formed by a photolithography technique. Therefore, adoption of this structure does not increase the TFT manufacturing process. .

[0039]

As described above, according to the present invention, the light leakage from between the lead wiring and the terminal can be reduced by the light-shielding pattern. You can get the display.

[Brief description of the drawings]

FIG. 1A is a plan view showing a liquid crystal display device according to an embodiment of the present invention, and FIG. 1B is a side view thereof.

FIG. 2A is an enlarged view of a portion I of FIG. 1A, and FIG. 2B is a cross-sectional view taken along line gg ′ of FIG. 2A.

FIG. 3 is a sectional view taken along line a-a ′ of FIG.

FIG. 4A is a cross-sectional view showing a thin film transistor (TFT) used for a liquid crystal panel of a liquid crystal display device according to the present invention, and FIGS. FIG. 4 is a cross-sectional view showing a manufacturing process to be performed.

5A is a diagram showing the amount of leaked light from the periphery of the display unit to the inside of the display unit according to the embodiment of the present invention, and FIG. 5B is a diagram showing the amount of leaked light from the periphery of the display unit to the inside of the display unit in a conventional example; It is.

6A is a plan view showing a liquid crystal display device according to a conventional example, and FIG. 6B is a side view thereof.

FIG. 7A is an enlarged view of an enlarged part II in FIG. 6;
(B) is a sectional view taken along the line hh 'of (a).

FIG. 8 is a sectional view taken along line d-d ′ of FIG.

FIG. 9 is a sectional view taken along line e-e ′ in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 101 Fluorescent tube 102 Liquid crystal panel 103 Lead-out wiring part 104 Terminal block 105 Light-shielding pattern 106 Display part 107 Reflector 108 Lead-out wiring 109 Terminal 110 Light guide plate 301 TFT side glass substrate 302 Transparent counter electrode 303 Transparent pixel electrode 304 Seal 305 Liquid crystal 306 Light source 307 TFT Side polarizing plate 308 Opposite side glass substrate 309 Opposing side polarizing plate 401 TCP 402 Driving circuit 501 Gate electrode 502 Source electrode 503 Drain electrode 504 Insulating layer 505 a ^- si pattern 506 n ⁺ a ^- Si pattern 507 Passivation layer 601 Light beam 701 shield

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G02F 1/136 G02F 1/1345 G09F 9/00

Claims (1)

(57) [Claims] 1. A liquid crystal display device comprising a pair of substrates, a liquid crystal, and a light-shielding pattern, wherein one of the paired substrates has a matrix of transparent pixel electrodes on a glass substrate, A lead wiring portion and a terminal block provided for applying a voltage to the pixel electrode; and the lead wiring portion and the terminal block have a light-shielding property. A counter electrode is formed on the substrate, the liquid crystal is sealed between the paired substrates, and the light-shielding pattern is formed of a lead wire provided in the lead wire portion and a terminal provided in the terminal block. different made conductive layer, it and is so made form <br/> as not to intersect the lead wire and between the terminal block of the lead-out wiring portion, the lead wires and between end is A liquid crystal display device, characterized in that for blocking passing light between the blocks.