JP2004077702A - Flat panel display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce lowering of a production yield due to generation of cell release and to prevent light leakage to the outside through a light shielding layer and to the inside of an effective display region from the outside by preventing an end part of the light shielding layer from being exposed to the side farther outer than a sealant to seal an array substrate and a counter substrate. <P>SOLUTION: The liquid crystal display device 1 is characterized by making a corner part of the light shielding layer 250 have a shape to which stress concentration hardly occurs so as to prevent the light leakage to the outside from the effective display region 102 comprising a liquid crystal layer 410 disposed between the array substrate 200 and the counter substrate 400 or the light entering in the effective display region from the outside. By making use of this construction, the lowering of the production yield due to generation of the cell release is reduced and the light leakage is prevented. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a flat display device represented by a liquid crystal display device or the like.
[0002]
[Prior art]
2. Description of the Related Art Flat display devices represented by liquid crystal display devices and the like are used in various fields by utilizing features of light weight, thin shape, and low power consumption.
[0003]
Among them, liquid crystal display devices are widely used in portable information devices represented by personal computers.
[0004]
In today's liquid crystal display device manufacturing process, in order to eliminate the need for unnecessarily increasing the alignment accuracy between the array substrate and the counter substrate, color filters, pixel electrodes, scanning lines and signal lines are provided on the array substrate side. There are many examples of placement.
[0005]
Further, the array substrate and the opposing substrate are hermetically sealed by a sealing material arranged outside the effective display area. A light-shielding layer having a light-shielding property is provided in a frame shape in a predetermined region between the substrates facing each other and between the inside of the sealing material and the outside of the effective display region.
[0006]
[Problems to be solved by the invention]
By the way, although the sealing material is provided so as to cover the outside of the light shielding layer, a corner of the light shielding layer may be exposed outside the sealing material at the end of the light shielding layer.
[0007]
When the light-shielding layer is exposed more than the sealing material, there is a problem that cell peeling and a decrease in yield occur.
[0008]
Therefore, it is conceivable to separate the light-shielding layer end from the sealing material end. However, when the liquid crystal cell is assembled as a module, light leakage may occur from the gap. In particular, according to recent narrow frame designs, light leakage may be visually recognized by an observer.
[0009]
An object of the present invention is to prevent the end portion of the light-shielding layer from being exposed to the outside of the sealing material that seals the array substrate and the opposing substrate, to reduce the occurrence of cell peeling and reduce the yield, An object of the present invention is to provide a flat display device capable of preventing desired light leakage.
[0010]
[Means for Solving the Problems]
The present invention relates to a scanning line and a signal line provided in a matrix on one main surface, a switch element provided at each intersection of the scanning line and the signal line, and a pixel electrode connected to the switch element. A substantially rectangular active matrix substrate, a substantially rectangular counter substrate provided with a counter electrode facing the pixel electrode, and a frame-like sealing material for bonding the array substrate and the counter substrate with a predetermined gap. And a light modulation layer disposed in the gap, a flat display device comprising:
Either the array substrate or the opposing substrate includes a curved corner along the corner of the frame-shaped sealing material, and a light-shielding layer disposed between the pixel electrode and the sealing material. A flat display device characterized by comprising:
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0012]
As shown in FIG. 1, the liquid crystal display device 1 includes a liquid crystal panel 100 in which a liquid crystal material is sealed, and a driving circuit 500 capable of supplying image information to be displayed by the liquid crystal panel 100 and a driving power. I have.
[0013]
The liquid crystal panel 100 and the drive circuit board 500 are electrically connected via a flexible printed circuit board (hereinafter, referred to as a highly flexible wiring material, abbreviated as FPC) 550. One end of the FPC 550 is connected to a connection electrode 171 provided at a predetermined position on the array substrate 200 by, for example, an anisotropic conductive film (ACF) 551 (see FIG. 2). The other end of the FPC 550 is similarly connected to the drive circuit board 500 by the ACF 551.
[0014]
The liquid crystal panel 100 includes an arbitrary number of signal lines X, an arbitrary number of scanning lines Y, an arbitrary number of scanning lines Y, and a signal line X and a scanning line Y between a first substrate, ie, an array substrate 200 and a second substrate, ie, a counter substrate 400. And a plurality of pixels Px including a switching element 211 which is a thin film transistor (TFT) arranged near the intersection with the pixel Px. Although not shown in FIG. 1, for example, a TN (twisted nematic) type liquid crystal material is sealed between the two substrates. Each pixel Px is provided with a storage capacitor C.
[0015]
The signal lines X and the scanning lines Y are connected to an X driver 151 and a Y driver 161 formed integrally on the first substrate 200. Note that a connection electrode portion (not shown) used for connection between each driver and the FPC 550 is also provided integrally with the first substrate 200.
[0016]
FIG. 2 is a schematic sectional view illustrating an example of the configuration of a liquid crystal panel applicable to the liquid crystal display device shown in FIG.
[0017]
As shown in FIG. 2, the liquid crystal panel 100 has an effective display area 102 in which a plurality of display pixel units Px arranged in a matrix are provided, and a drive circuit unit (peripheral electrode unit) 110.
[0018]
Between the array substrate 200 and the counter substrate 400 of the liquid crystal panel 100, a liquid crystal layer 410 held via an alignment film is provided. The two glass substrates are, for example, non-alkali glass plates having a thickness of 0.7 mm and are light-transmitting insulating substrates.
[0019]
On one main surface (front surface) of the glass plate 201 on the side of the array substrate 200, a plurality of signal lines X and a plurality of scanning lines Y arranged in a matrix are arranged near intersections of the signal lines X and the scanning lines Y. A switching element 211 composed of a thin film transistor, that is, a TFT, and a pixel electrode 213 connected to the switching element 211 are provided.
[0020]
The switch element 211 includes, as an active layer, a channel region 212c and a polycrystalline silicon (low-temperature polysilicon) film including a source region 212s and a drain region 212d interposed between the channel region 212c, that is, a p-Si film.
[0021]
The gate electrode 215 of the switch element 211 is made of, for example, a MoW alloy film, is arranged on the channel region 212c of the p-Si film via a gate insulating film 214 made of a TEOS film or the like, and is connected to the scanning line Y. Note that the scanning line Y is also formed integrally with the gate electrode 215 using a MoW alloy.
[0022]
The source electrode 216s of the switch element 211 is made of, for example, a Mo / AlNd / Mo alloy (hereinafter abbreviated as MAM film) film, and is connected to the source region 212s and to the pixel electrode 213.
[0023]
The drain electrode 216d of the switch element 211 is made of, for example, a MAM film, and is connected to the drain region 212d and to the signal line X. Note that the signal line X is also formed integrally with the drain electrode 216d by an alloy.
[0024]
The pixel electrode 213 is formed of a light-transmissive conductive member, for example, ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide). The pixel electrode 213 is formed by exposing and developing an interlayer insulating film 217 made of an oxide film such as SiO ₂ or a nitride film such as SiNx and a color resist layer on the switch element (TFT) 211 in order. It is arranged on the filter layer CF. In this embodiment, silicon nitride is used for the interlayer insulating film 217.
[0025]
The color filter layer CF is formed of, for example, a negative color resist layer colored red, green, and blue, respectively. The color filter layer CF of each color is arranged for each display pixel portion Px of the corresponding color.
[0026]
The alignment film 219 is disposed over the entire effective display area 102 so as to cover all the pixel electrodes 213.
[0027]
On one main surface (front surface) of the glass plate 401 on the counter substrate 400 side, a counter electrode 403 arranged to face the pixel electrode 213 is provided.
[0028]
The counter electrode 403 is formed of a light-transmissive conductive member, for example, ITO.
[0029]
The alignment film 405 is disposed on the entire effective display area 102 so as to cover the entire counter electrode 403.
[0030]
In the effective display area 102, a columnar spacer 104 that forms a predetermined gap between the array substrate 200 and the counter substrate 400 is arranged. The columnar spacer 104 is formed of, for example, a black resin on the array substrate 200.
[0031]
Outside the effective display area 102, a light shielding layer 250 is arranged in a frame shape. The light-shielding layer 250 is a resin having a light-shielding property, and is formed of, for example, a black resin similar to the resin used for the columnar spacer 104.
[0032]
The array substrate 200 and the counter substrate 400 are bonded together by the sealing material 106 in a state where a predetermined gap, for example, a gap of 4 μm is formed by the column spacer 104.
[0033]
As shown in FIG. 3, the seal member 106 and the light shielding layer 250 have a structure in which the seal member 106 is disposed outside the light shield layer 250 when viewed from the plane. In many cases, the sealing material 106 is also applied at predetermined corners R at the end of the light shielding layer 250 due to application characteristics (shape) restricted by the dispenser and viscosity of the sealing material itself.
[0034]
The light-shielding layer 250 is patterned in advance so as to have a curved portion (corner R) 250a having a predetermined curvature at an end, that is, a corner. Note that the curved portion 250a of the light-shielding layer 250 is defined as at least the outer peripheral portion of the light-shielding layer 250 arranged so as to surround the peripheral portion of the effective display area 102.
[0035]
As described above, by forming the end portion of the light shielding layer 250 with the corner R (curved portion) 250 a, when the sealing material 106 is arranged around the light shielding layer 250, the sealing material 106 The end can be prevented from being exposed.
[0036]
Thus, when the array substrate 200 and the opposing substrate 400 are bonded to each other to form a cell, cell peeling occurs and the yield decreases, light leaks from the effective display area 102 to the outside, or the effective display area from the outside. It is possible to prevent light from leaking to the light emitting element 102.
[0037]
Note that, by forming the end of the light-shielding layer 250 to have a shape formed of the corner R250a, the width of the portion other than the corner of the light-shielding layer 250 can be increased. In this case, it goes without saying that the light shielding property of the light shielding layer 250 is enhanced. Further, by setting the end of the light shielding layer 250 as the corner R, stress concentration is avoided, and the strength of the cell is increased.
[0038]
Further, as shown in FIG. 4, an end portion of the light-shielding layer 250 is formed into an R shape 250a, and a metal pattern 108 having an arbitrary shape is provided in a region outside the light-shielding layer 250 where no wiring is provided. In addition, the light shielding property can be improved.
[0039]
In the peripheral area of the effective display area 102, an integrated drive circuit unit 110 is arranged. Although the driving circuit unit 110 has been schematically described with reference to FIG. 1, the signal line driving circuit unit 151 that supplies an image signal to an arbitrary signal line X and the scanning line driving that supplies a scanning pulse to each scanning line Y The circuit 161 is included. Note that each of the signal line driving circuit portion (Y driver) 151 and the scanning line driving circuit portion (X driver) 161 is formed of a thin film transistor including a polycrystalline silicon film, similarly to the switch element provided in the effective display region 102. Have been.
[0040]
On the outer surface of the array substrate 200 and on the outer surface of the counter substrate 400, a pair of polarizing plates 220 and 407 whose polarization directions are set according to the characteristics of the liquid crystal layer 410 are provided. That is, on the other main surface (back surface) of the insulating substrate 201 forming the array substrate 200, the polarizing plate 220 attached by the adhesive 221 is provided on the other main surface of the insulating substrate 401 forming the counter substrate 400. On the (back surface), the polarizing plates 407 adhered by the adhesive 406 are arranged respectively.
[0041]
Hereinafter, a backlight unit 800 including a surface light source unit 810 and at least one optical sheet 820 that provides predetermined optical characteristics to light emitted from the surface light source unit 810 is provided on the polarizing plate 220 side. The surface light source unit 810 includes, for example, a light guide plate having the same size as the liquid crystal panel 100, a tubular light source disposed on an end face of the light guide plate, a reflector plate for guiding light emitted from the tubular light source to an end face of the light guide, and the like. It is constituted by. The optical sheet 820 includes a prism sheet that condenses the light emitted from the surface light source unit 810, a diffusion sheet that diffuses the light, and the like. An optical sheet 820 constituting the backlight unit 800 is attached to the surface of the polarizing plate 220 via an adhesive 821.
[0042]
The present invention is not limited to the above embodiments, and various modifications and changes can be made at the stage of implementation without departing from the scope of the invention. In addition, the embodiments may be implemented in appropriate combinations as much as possible. In that case, the effects of the combinations are obtained.
[0043]
As described above, according to this embodiment, it is possible to effectively prevent the corners of the light-shielding layer from being exposed to the outside of the sealing material, and thus to effectively prevent cell peeling and the like. In particular, in this embodiment, the light-shielding layer is made of the same material and in the same process as the columnar spacer, and has a thickness of about 4 μm. However, according to this embodiment, the corners of the light-shielding layer are more effectively prevented from being exposed to the outside than the sealing material, so that a special effect is obtained when combined with such a light-shielding layer.
[0044]
【The invention's effect】
As described above, according to the present invention, it is possible to prevent the end of the light-shielding layer from being exposed to the outside than the sealing material that seals the array substrate and the opposing substrate, thereby preventing cell peeling and lowering the yield. There is provided a flat panel display device capable of reducing the number of light leakage and preventing unwanted light leakage.
[Brief description of the drawings]
FIG. 1 is a schematic view illustrating an example of a liquid crystal display device to which an embodiment of the present invention can be applied.
FIG. 2 is a schematic cross-sectional view illustrating an example of a liquid crystal panel applicable to the liquid crystal display device shown in FIG.
FIG. 3 is a schematic plan view illustrating a state where the liquid crystal display device shown in FIGS. 1 and 2 is viewed from a plane direction.
FIG. 4 is a schematic plan view illustrating an example of another embodiment of the configuration of the light-shielding layer shown in FIG.
[Explanation of symbols]
1 ... LCD module,
100 ... liquid crystal panel,
102 ... effective display area,
104 spacers
106 ... sealing material,
108 metal pattern,
110 ... drive circuit section (peripheral electrode section)
200 ... array substrate,
201: glass substrate,
250 ... light-shielding layer,
250a, corner R (light shielding layer),
400 ... counter substrate,
401 ... glass substrate.

Claims (6)

A scanning line and a signal line provided in a matrix on one main surface, a switching element provided at each intersection of the scanning line and the signal line, and a pixel electrode connected to the switching element. A rectangular active matrix substrate,
A substantially rectangular counter substrate including a counter electrode facing the pixel electrode;
A frame-shaped sealing material for bonding the array substrate and the counter substrate with a predetermined gap,
A light modulation layer disposed in the gap,
In a flat panel display device having
Either the array substrate or the opposing substrate includes a curved corner along the corner of the frame-shaped sealing material, and a light-shielding layer disposed between the pixel electrode and the sealing material. A flat panel display device comprising: 2. The flat panel display according to claim 1, wherein an end of the light shielding layer is in contact with an end of the sealing material. 2. The liquid crystal display device according to claim 1, wherein the light shielding layer is made of a black resin material disposed on an array substrate. The flat panel display according to claim 1, wherein the array substrate includes a columnar spacer made of the black resin material. 2. The liquid crystal display device according to claim 1, wherein a curvature of a corner of the light shielding layer is previously patterned in a curved shape when patterning the light shielding layer. 2. The liquid crystal display device according to claim 1, wherein a metal layer is provided outside the light shielding layer along the sealing material.

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