JP2002258264A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent leakage of light from a backlight and to prevent display quality from deteriorating in a transmissive liquid crystal display device. SOLUTION: On a colored layer 25a extending to the outside of a seal 35 on an array side glass substrate 11, a colored layer 33 is formed, of which the color is different from that of the colored layer 25a. A double-coloring-layer area 27 is thereby provided between the seal 35 and the end part of the array side glass substrate 11. The light leaked from the backlight is thus shielded with the double-coloring-layer area 27.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming a colored layer on an array substrate, bonding the outer periphery of the array substrate and a counter substrate with a sealing material, filling a gap between the two substrates with liquid crystal, and forming a pixel region. The present invention relates to a liquid crystal display device to be formed.

[0002]

2. Description of the Related Art In a liquid crystal display device, two electrode substrates having an alignment film are arranged so that the alignment films face each other, and a liquid crystal layer is sandwiched between the two substrates. The two electrode substrates are bonded together by a sealing material and a sealing material arranged in a peripheral region, and a spacer pillar made of a granular spacer or a resin is provided between the two substrates to maintain a distance between the substrates. Are located.

When a liquid crystal display device displays a color image,
A colored layer composed of red (R), green (G), and blue (B) is often arranged on one of the substrates. Usually, a frame-shaped black matrix (hereinafter, also referred to as BM) is formed outside the display pixel area to prevent light leakage from the backlight.

Generally, a metal thin film such as Cr or MoW or a resin is used as the BM material. When a colored layer is formed on the array substrate side, the spacer pillar and the BM are simultaneously formed with a black colored layer in addition to the R, G, and B colored layers. At this time,
By forming the black coloring layer on the RGB coloring layer, a desired cell gap can be obtained.

[0005] In recent years, liquid crystal display devices capable of obtaining high-performance and high-definition displays with high density and large capacity have been put into practical use. There are various types of liquid crystal display devices. Among them, an active matrix type liquid crystal display device has a small crosstalk between adjacent pixels, a high contrast display can be obtained, and a transmission type display is possible and a large area is easy. Liquid crystal display devices are widely used. In this active matrix type liquid crystal display device, pixel electrodes using TFTs as switching elements are arranged in a matrix in a plurality of regions defined by a plurality of scanning lines and a plurality of signal lines provided in directions intersecting each other. An array substrate is provided.

In an active matrix type liquid crystal display device, the potential of a pixel electrode to which image data is written during a period in which a scanning line is selected depends on the potential change of an adjacent signal line due to a parasitic capacitance or an off-leak current of a TFT in a non-selection period. Under the influence, crosstalk is generated and the contrast ratio is reduced. In order to suppress such deterioration in image quality, a liquid crystal display device of this type generally has a configuration in which an auxiliary capacitor is formed electrically in parallel with a pixel electrode. In addition, a BM is used to prevent light leakage between pixels. Is provided.

Conventionally, the BM is generally disposed together with a color layer for a color filter on a counter substrate which is disposed to face an array substrate via a liquid crystal layer. However, in such a structure, it is necessary to consider the misalignment between the array substrate and the counter substrate, which causes a reduction in the ratio of the light-transmitting apertures (aperture ratio).

For this reason, in recent years, a transparent organic insulating film is provided on the wiring of the array substrate, a pixel electrode is provided on the uppermost layer, and an end of the pixel electrode is overlapped with the wiring provided in a matrix. Accordingly, a wiring BM structure using a wiring as a BM has been used. Further, in some cases, a structure using a colored layer of a cuff filter formed on a counter substrate instead of the organic insulating film may be used. In these structures, when forming a colored layer, R, G, B
In addition to the colored layers, a spacer pillar and a greenish BM outside the display area are simultaneously formed using a black colored layer.

Incidentally, in recent years, systems such as notebook type personal computers incorporating a liquid crystal display device have been reduced in frame size, and the number of narrow green frames has been increasing. For this reason, the assembly tolerance between the liquid crystal display device and the system is strict, and light leakage of the backlight may occur from the periphery of the display area, thereby deteriorating the display quality.

FIG. 2 is a partial sectional view showing a configuration example of a conventional liquid crystal display device. The array-side glass substrate 11 and the opposing-side glass substrate 21 are opposed to each other with a predetermined gap. An opposing electrode 22 is provided inside the opposing glass substrate 21.
Is formed, and an alignment film 13 is further formed on the surface of the counter electrode 22. On the other hand, the array-side glass substrate 11
An interlayer insulating film 23 is formed on the inside of the substrate, and the signal line 14, the source electrode 15, and the liquid crystal driving circuit wiring 1 are further formed thereon.
6 are formed. The interlayer insulating film 23 is provided for these signal lines 1
4 and the source electrode 15 and the liquid crystal drive circuit wiring 16 are covered with a protective insulating film 24. Note that a part of the liquid crystal drive circuit wiring 16 bites into the interlayer insulating film 23 and is in contact with the array-side glass substrate 11. The array-side glass substrate 11 and the coloring layer 25 constitute an array substrate 110 with a color filter, and the opposite-side glass substrate 21 and the opposite electrode 2
Reference numeral 2 denotes a counter substrate 120.

A colored layer 25 is formed on the protective insulating film 24, and a pixel electrode 30 is formed on an upper surface of the colored layer 25. The pixel electrode 30 is connected to the source electrode 15 via a through hole 26 formed in the coloring layer 25 and the protective insulating film 24. The upper surface of the coloring layer 25 including the pixel electrode 30 is covered with the alignment film 13.

A plurality of spacer columns 31 are provided between the alignment film 13 on the array side glass substrate 11 and the alignment film 13 on the opposite side glass substrate 21, and a gap between the two glass substrates 11, 21 is formed. The gap is filled with liquid crystal to form a liquid crystal layer 70. Array side glass substrate 1
Around the end of the glass substrate 21 on the opposite side to the seal 1, a seal 35 is provided.
Is provided, and the two substrates are adhered to each other, and the liquid crystal is sealed inside. Immediately inside the seal 35, the frame BM32 is a colored layer 2.
5 is formed on the array-side glass substrate 11 side in such a manner as to divide the substrate 5.

[0013]

In the conventional liquid crystal display device as described above, it is necessary to provide a spacer column 31 outside the seal 35 in order to keep a uniform gap. When the backlight is illuminated from the outside (below) of the array side glass substrate 11 in such a configuration, the light of the color of the colored layer 25 outside the seal 35 serving as the base of the spacer pillar 31 is emitted from the periphery of the display area to the outside. It leaks and is visually recognized. That is, when the color of the outer colored layer 25 is red (R), red light is emitted, when the colored layer 25 is blue (B), blue light is emitted, and when the colored layer 25 is green (G), green light is emitted. However, there is a problem in that the light leaks as shown by the symbol P in the drawing and is visually recognized as light leak by the user, thereby deteriorating the display quality.

An object of the present invention is to provide a high-quality liquid crystal display device in which light leakage from a backlight is prevented to prevent a deterioration in display quality.

[0015]

In order to achieve the above object, according to the first aspect of the present invention, a counter substrate and an array substrate having a color layer as a color filter are arranged so as to surround the outer periphery of both substrates. Adhering by the formed seal, forming a display area by sandwiching a liquid crystal layer in the gap between the two substrates,
In a liquid crystal display device that irradiates a backlight from the outside of the array substrate, by forming a colored layer of a different color from the colored layer on the colored layer extending outside the seal on the array substrate. A two-layer region of a coloring layer between the seal and the end of the array substrate.

According to a second aspect of the present invention, in the first aspect, the colored layer of another color is formed on the outside of the seal in a process of forming a colored layer of the same color as the colored layer on the array substrate. Characterized in that they are simultaneously formed on the upper part of the colored layer that extends.

According to a third aspect of the present invention, in the first or second aspect, the two colored layers are a red colored layer and a blue colored layer.

According to a fourth aspect of the present invention, in the first to third aspects, a plurality of spacer columns are provided between the counter substrate and the array substrate to hold a predetermined gap between the two substrates. It is characterized by.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1A is a front view illustrating a configuration according to an embodiment of a liquid crystal display device of the present invention, and FIG. 1B is a cross-sectional view taken along line AB of the front view. However, the same parts as those in the conventional example of FIG. 2 are denoted by the same reference numerals, and the description thereof will be appropriately omitted.

As shown in FIG. 1B, the liquid crystal display 1
0 denotes a counter substrate (a counter glass substrate 21, a counter electrode 22).
The liquid crystal layer 70 is sandwiched between an array substrate 120 having a color filter (composed of the array-side glass substrate 11 and the colored layer 25) 110, and the distance between these two substrates is set from the resin. Are held by the spacer pillars 31. The opposing substrate 120 and the array substrate 110 with a color filter are adhered by a seal 35 disposed so as to surround the outer periphery of the substrate except for a liquid crystal injection port (not shown). Is applied. On the opposing glass substrate 21, a transparent electrode 22 made of ITO and an alignment film 13 are sequentially formed.

The array substrate 110 with a color filter is
A scanning electrode (not shown), an auxiliary capacitance electrode provided in parallel with the scanning electrode, and a signal line 14 orthogonal to the scanning electrode and an insulating film 22 are formed on the array side glass substrate 11, and near the intersection of the scanning line and the signal line. As the switching element, a TFT element having an Nch LDD structure (not shown), a source electrode 15 electrically connected to the switching element, and a pixel electrode 30 connected to the source electrode 15 are formed.

In the liquid crystal display device 10, a liquid crystal drive circuit (not shown) is formed around the display area at the same time as the switching element, and a plurality of wirings 16 necessary for operating the liquid crystal drive circuit are provided near the display area. Book is provided.
Then, a protective insulating film 24 is provided so as to cover the switching element and the liquid crystal drive circuit, and further thereon a green coloring layer (G) 25, a blue coloring layer (B) 25, and a red coloring layer (R) 25. Are arranged in a stripe pattern.

The pixel electrode 30 is formed on the colored layer 25 and is connected to the source electrode 15 via a through hole 26 formed in the colored layer 25 and the protective insulating film 24. Further, an alignment film 13 is formed on the entire surface of the substrate so as to cover the pixel electrode 30 and the coloring layer 25.

Also in this example, a frame B is provided immediately inside the seal 35.
M32 is arranged on the array side glass substrate 11 side so as to divide the colored layer 25. Between the outside of the seal 35 and the end of the display area, a colored layer 33 of a different color from the colored layer 25a is formed on the colored layer 25a serving as a base of the seal 35. As the coloring layer 25a and the coloring layer 33,
By using a combination of a red coloring layer and a blue coloring layer, the highest light blocking effect can be obtained.

Next, a method of manufacturing the active matrix type liquid crystal display device configured as described above will be described.

First, a CV is placed on a light-transmitting insulating substrate (array-side glass substrate 11) such as a high-strain-point glass substrate or a quartz substrate.
An a-Si film is deposited by the D method or the like. After performing furnace annealing, XeCl excimer laser is irradiated to polycrystallize a-Si. Thereafter, the polycrystalline Si is patterned by a photoetching method to become a channel layer of a TFT in a pixel portion in a display region (not shown) and a channel layer of a TFT (circuit TFT) in a liquid crystal drive circuit region (not shown). A polysilicon film (not shown) serving as a lower electrode of the device is formed.

Next, an SiOx film serving as a gate insulating film (not shown) is deposited on the entire surface of the insulating substrate to a thickness of about 100 nm by the CVD method. Subsequently, Ta, Cr,
A single element such as A1, Mo, W, Cu, or a laminated film or an alloy film thereof is deposited and patterned into a predetermined shape by a photoetching method. The gate electrode of the pixel TFT, the auxiliary capacitance line, the gate electrode of the circuit TFT, and various wirings in the drive circuit area are formed. At this time, the wiring 16 necessary for driving the liquid crystal driving circuit is formed at the same time.

Then, impurities are implanted by ion implantation or ion doping using these gate electrodes as a mask, thereby forming a source electrode 15 of a pixel TFT, a drain electrode (not shown), and a source electrode of an Nch type circuit TFT (not shown). And a drain electrode are formed.

Next, the pixel TFT (not shown) and the Nch-type circuit TFT in the drive circuit region are covered with a resist so as not to be doped with impurities, and then boron is formed using the gate electrodes of the Pch-type circuit TFT (not shown) as masks. To form a source electrode and a drain electrode of a Pch type circuit TFT.

Thereafter, an Nch type LDD (not shown)
(Lightly Doped Drain) is implanted, and impurities are activated by annealing the substrate.

Further, an interlayer insulating film SiO2 is deposited on the entire surface of the insulating substrate by using, for example, the PECVD method.

Subsequently, a contact hole 26 reaching the source electrode 15 of the pixel TFT, a contact hole reaching the drain electrode (not shown), and a contact hole reaching the source electrode and drain electrode of the circuit TFT (not shown) are formed by photoetching. .

Next, Ta, Cr, Al, Mo, W, Cu
Such as a simple substance or a laminated film or an alloy film thereof, and patterned in a predetermined shape by a photo etching method,
The connection between the signal line 14, the drain electrode of the pixel TFT (not shown) and the signal line 14, the source electrode 15, and various wirings of the circuit TFT in the liquid crystal drive circuit region (not shown) are performed.

Further, a protective insulating film 24 made of SiNx is formed on the entire surface of the insulating substrate by the PECVD method, and a contact hole 26 reaching the display pixel electrode 30 is formed by a photo etching method.

Next, an ultraviolet curable acrylic green resist solution is applied to the substrate on which the electrodes are formed by spinner coating. Subsequently, the substrate is pre-baked and exposed using a predetermined mask pattern. The photomask pattern used here has a stripe-shaped pattern corresponding to the green coloring layer and a through hole 26 for connecting the pixel electrode 30 and the source electrode 15.

Subsequently, after washing with developing water, post-baking is performed to form a green colored layer (G) 25 having through holes 26. Subsequently, a blue colored layer (B)
25, a red colored layer (R) 25 is also formed in the same step. In this case, the end of the G pattern is covered with the B layer or the R layer. This is achieved by making the exposure mask used when processing each colored layer suitable as described above. Further, except for a region where the spacer pillar 31 outside the seal 35 is arranged, two colored layers having different colors among the three colored layers of R, G, and B are formed. In this embodiment, the red coloring layer 25a and the blue coloring layer 33 are formed.

Next, indium tin oxide (ITO) is deposited on the coloring layer 25 by a sputtering method, and is patterned to form a pixel electrode 30. After that, the spacer pillar 31 and the foreground BM 32 are formed by the black colored layer 25. The frame BM32 is shown in FIG.
The black frame area 28 shown in FIG. Thereafter, an alignment film material made of polyimide is applied to the entire surface of the substrate, and an alignment process is performed to form an alignment film.
Get.

Next, an ITO is deposited on the transparent substrate 21 by a sputtering method to form a counter electrode 22. Subsequently, an alignment film material made of polyimide is applied to the entire surface of the substrate and subjected to an alignment treatment to form an alignment film. Thus, a counter substrate 120 is obtained. A sealing material (not shown) is applied to the outer peripheral portion of the counter substrate 120 except for an injection port for injecting liquid crystal. This counter substrate 120
And the substrate 110 with a color filter are bonded together with the sealing material 35 to complete the empty bear cell. Next, the nematic liquid crystal material to which the chiral material was added was vacuum-injected into the cell from the injection port, and after injection, the injection port was sealed using an ultraviolet curable resin as a sealing material. The liquid crystal display device is completed by disposing the polarizing plates.

According to the present embodiment, a colored layer 33 having a color different from that of the colored layer 25a is formed on the colored layer 25a outside the seal 35 to form a colored layer two-layer region 27. Since the colored layer two-layer region 27 is located outside the display pixel region 40 and between the black frame region 28 and the substrate outer end 29 as shown in FIG. When the backlight is illuminated from outside (below), the colored layer two-layer region 27 has a light-shielding effect equivalent to that of the BM, and light can be prevented from leaking outside through this portion. Thus, light leakage from the backlight can be prevented, and deterioration of display quality can be prevented.

In the present embodiment, an example is shown in which a red colored layer 25a and a blue colored layer 33 having the highest light-shielding effect are formed as two colored layers having different colors. Can be selected.

In the above embodiment, the spacer pillar 31
Is located on the colored layer 33 side, so that the spacer layer 31 has a configuration in which the colored layer 33 is removed. However, the spacer pillar 31 is not necessarily required in the colored layer 33 portion. The colored layer 33 having a uniform thickness is formed.

[0042]

As described above, according to the present invention,
By forming two colored layers having different colors on the outer portion of the seal, light leakage from the backlight can be prevented. Therefore, a reduction in display quality can be prevented and a high-quality liquid crystal display device can be provided. it can.

[Brief description of the drawings]

FIG. 1A is a front view illustrating a configuration according to an embodiment of a liquid crystal display device of the present invention, and FIG. 1B is a cross-sectional view taken along a line AB.

FIG. 2 is a cross-sectional view illustrating a configuration example of a conventional liquid crystal display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Liquid crystal display device 11 ... Array side glass substrate 13 ... Alignment film 14 ... Signal line 15 ... Source electrode 16 ... Liquid crystal drive circuit wiring 21 ... Opposite side glass substrate 22 ... Opposite electrode 23 ... Interlayer insulating film 24 ... Protective insulating film 25, 25a, 33 ... Colored layer 26 ... Through hole 27 ... Colored layer 2 layer region 30 ... Pixel electrode 31 ... Spacer pillar 32 ... Frame BM 35 ... Seal 40 ... Display pixel region 70 ... Liquid crystal layer 110 ... Array substrate with color filter 120: Counter substrate

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G09F 9/30 320 G09F 9/30 320 349 349C (72) Inventor Tetsuya Iizuka Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa 8 Toshiba Electronic Engineering Co., Ltd. F-term (reference) 2H048 BA11 BA45 BB02 BB03 BB08 BB44 2H089 LA09 LA41 MA03X QA05 TA01 TA09 TA12 TA18 2H091 FA02Y FA41Z GA01 GA13 LA03 5C094 AA02 AA16 BA13 BA43 CA03 EA04 EA03 EA04 ED15

Claims (4)

[Claims] 1. An opposing substrate and an array substrate having a color layer as a color filter are adhered to each other by a seal formed so as to surround an outer periphery of the two substrates, and a liquid crystal layer is sandwiched in a gap between the two substrates. A liquid crystal display device that forms a display area and irradiates a backlight from outside the array substrate, wherein a color different from the color layer is provided on a color layer extending outside the seal on the array substrate. A liquid crystal display device comprising a two-layer region of a colored layer between the seal and the end of the array substrate by forming the colored layer of (1). 2. The colored layer of another color is simultaneously formed on the colored layer extending outside the seal in a process of forming a colored layer of the same color as the colored layer on the array substrate. 2. The method according to claim 1, wherein
3. The liquid crystal display device according to 1. 3. The liquid crystal display device according to claim 1, wherein the two colored layers are a red colored layer and a blue colored layer. 4. The method according to claim 1, wherein a plurality of spacer posts are provided between the opposing substrate and the array substrate to hold a predetermined gap between the two substrates. Liquid crystal display.