CN1333295C

CN1333295C - Pixel structure suitable for wide viewing angle liquid crystal display

Info

Publication number: CN1333295C
Application number: CNB2005100650960A
Authority: CN
Inventors: 吴明洲; 苏振嘉; 曹正翰; 陈伯纶
Original assignee: AU Optronics Corp
Current assignee: AUO Corp
Priority date: 2005-04-14
Filing date: 2005-04-14
Publication date: 2007-08-22
Anticipated expiration: 2025-04-14
Also published as: CN1664678A

Abstract

The present invention discloses a pixel structure suitable for a wide-viewing angle liquid crystal display, which includes a substrate, a pixel electrode, and a storage capacitor. The pixel electrode is arranged above a pixel region of the substrate and has at least one slit. The storage capacitor is arranged between the substrate and the pixel electrode and includes a lower electrode, a capacitor dielectric layer, and an upper electrode. The lower electrode is arranged in the pixel region and has an overlap region with the slit. The capacitor dielectric layer and the upper electrode are arranged on the lower electrode in sequence, wherein the upper electrode has at least one recessed region to partially expose the overlap region.

Description

Be applicable to the dot structure of wide-angle liquid crystal display

Technical field

The present invention relates to a kind of dot structure, relate in particular to a kind of dot structure that is applicable to wide viewing angle (wide-viewingangle) LCD.

Background technology

LCD (LCD) is the effect that utilizes extra electric field, makes liquid crystal molecule rotate and changes the LCD alignment state.LCD changes the variation of the various optical properties produced by liquid crystal alignment, and for example birefringence, optical activity, dichromatism etc. convert thereof into visual variation to reach the purpose of show image information.Because LCD has thin thickness, in light weight, low power consumption, and characteristics such as low operating voltage, be widely used on the electronic products such as Portable personal computer, digital camera, projector at present, and in flat-panel screens market, occupied an important position.

Present LCD is towards high brightness, high contrast, wide viewing angle, large tracts of land, and the trend development of full-colorization.Wherein, in order to solve the problem at visual angle, develop and a kind of multiple regions perpendicular orientation (multi-domain vertical alignment, MVA) LCD, it is that the liquid crystal region that will show usefulness is separated into multiple zone, use that liquid crystal molecule is toppled over towards a plurality of directions, and then increase the visual angle of LCD.In this kind LCD,, need control the orientation of liquid crystal usually with tilt angle (pre-tilt angle) in order accurately to control the toppling direction of liquid crystal molecule.The general common practice is to utilize the slit (slit) and the combination of teat (protrusion) to produce tilt angle.

Fig. 6 shows dot structure 100 diagrammatic cross-sections of traditional multiple regions perpendicular alignment liquid crystal display monitor.Dot structure 100 comprises: an infrabasal plate 101, a memory capacitance 102, an insulation course 104, an and pixel electrode 106.Infrabasal plate 101 for example is an array basal plate, and its top is sequentially provided with memory capacitance 102, insulation course 104, reaches pixel electrode 106.Typically, memory capacitance 102 comprises: a bottom electrode 102a, a capacitance dielectric layer 102b, an and top electrode 102c, wherein top electrode 102c is the contact hole 104a that sees through in the insulation course 104, and electrically connects with the pixel electrode 106 of top.Pixel electrode 106 has in order to the slit 106a that produces tilt angle and its can stride across memory capacitance 102 tops usually.

Yet the current potential that top electrode 102c is identical because of electric connection has with pixel electrode 106 makes the slit 106a be positioned at memory capacitance 102 tops (that is, the overlapping district of slit 106a and memory capacitance 102) can't form tilt angle.Therefore, be close to the middle meeting generation of liquid crystal layer (not illustrating) the disclination line (disclination line) at slit 106a place, memory capacitance 102 top.The generation of disclination line can cause the brightness decline and the increase of response time (response time) of MVA LCD.Especially, the problem of colour cast (color wash out) can be even more serious because of the generation of disclination line, makes the image quality of MVA LCD descend.

Summary of the invention

In view of this, the object of the present invention is to provide a kind of dot structure that is applicable to wide-angle liquid crystal display, it is by the shape that changes memory capacitance, to improve or to prevent that the slit of pixel electrode from producing the disclination line in the liquid crystal layer at contiguous memory capacitance place.

According to above-mentioned purpose, the invention provides a kind of dot structure that is applicable to wide-angle liquid crystal display, it comprises a substrate, a pixel electrode, reaches a memory capacitance.Pixel electrode is arranged at the pixel region top of substrate, and it has at least one slit.Memory capacitance is arranged between substrate and the pixel electrode, and it comprises a bottom electrode, a capacitance dielectric layer, reaches a top electrode.Bottom electrode is arranged in the pixel region, and itself and slit have an overlapping district.Capacitance dielectric layer is arranged on the bottom electrode, and top electrode is arranged at and electrically connects on the capacitance dielectric layer of bottom electrode top and with this pixel electrode, and this top electrode has at least one depressed area, exposes overlapping with the part and distinguishes.

According to above-mentioned purpose, the invention provides a kind of dot structure that is applicable to wide-angle liquid crystal display again, it comprises a substrate, a pixel electrode, reaches a memory capacitance.Pixel electrode is arranged at the pixel region top of substrate, and it has at least one slit.Memory capacitance is arranged between substrate and the pixel electrode, and it comprises a bottom electrode, a capacitance dielectric layer, reaches at least two top electrodes.Bottom electrode is arranged in the pixel region, and itself and slit have an overlapping district.Capacitance dielectric layer is arranged on the bottom electrode, and at least two top electrodes are arranged at and electrically connect on the capacitance dielectric layer of bottom electrode top and with this pixel electrode, and at least two top electrodes are separated by the overlapping district.

For above-mentioned purpose of the present invention, feature and advantage can be become apparent, preferred embodiment cited below particularly, and conjunction with figs. are described in detail below.

Description of drawings

Fig. 1 is the planimetric map that shows the dot structure that is applicable to wide-angle liquid crystal display according to an embodiment of the invention;

Fig. 2 a is the diagrammatic cross-section that shows among Fig. 1 along an embodiment of 2-2 line;

Fig. 2 b is the diagrammatic cross-section that shows the dot structure that is applicable to wide-angle liquid crystal display of another embodiment;

Fig. 3 is the planimetric map that shows the dot structure that is applicable to wide-angle liquid crystal display according to an embodiment of the invention;

Fig. 4 is the planimetric map that shows the dot structure that is applicable to wide-angle liquid crystal display according to an embodiment of the invention;

Fig. 5 is the planimetric map that shows the dot structure that is applicable to wide-angle liquid crystal display according to an embodiment of the invention;

Fig. 6 is the dot structure diagrammatic cross-section that shows traditional multiple regions perpendicular alignment liquid crystal display monitor.

Symbol description

Prior art:

100～dot structure; 101～infrabasal plate; 102～memory capacitance; 102a～bottom electrode; 102b～capacitance dielectric layer; 102c～top electrode; 104～insulation course; 104a～contact hole; 106～pixel electrode; 106a～slit.

The present invention:

200～infrabasal plate; 200a～pixel region; 201～gate line; 202～memory capacitance; 202a～bottom electrode; 202b～capacitance dielectric layer; 202c～top electrode; 203～data line; 204～insulation course; 204a, 204b～contact hole; 205～depressed area; 206～pixel electrode; 206a～slit; 207～district overlaps; 210～upper substrate; 210a～teat.

Embodiment

The dot structure that is applicable to wide-angle liquid crystal display that below cooperates Fig. 1 and 2a explanation one embodiment of the invention, wherein Fig. 1 is the planimetric map that shows the dot structure that is applicable to wide-angle liquid crystal display, and Fig. 2 a is the diagrammatic cross-section that shows among Fig. 1 along the 2-2 line.Herein, wide-angle liquid crystal display can be multiple regions perpendicular orientation (multi-domain vertical alignment, MVA) LCD.Dot structure comprises: infrabasal plate 200, a memory capacitance 202, an insulation course (sheath) 204, a pixel electrode 206, liquid crystal layer 208 and a upper substrate 210.Infrabasal plate 200 for example is that it is provided with many data lines and many gate lines by clear glass or the quartzy array base palte that is constituted.The row that intersects vertically puts and constitutes a plurality of pixel regions for these data lines and gate line., be to simplify accompanying drawing herein, only represent with a gate line 201, a data line 203 and the pixel region 200a that constituted by gate line 201 and data line 203.

Above pixel region 202, be provided with a thin film transistor (TFT) (not illustrating) and a pixel electrode 206 that is electrically connected to gate line 201 and data line 203.Herein, pixel electrode 206 is made of a transparency conducting layer, for example tin indium oxide (ITO).Wherein, pixel electrode 206 has at least one slit 206a, and in the present embodiment, this slit 206a arranges virtual raised structures in the liquid crystal display device structure as multiple regions perpendicular.In addition, on the pixel region 202 between pixel electrode 206 and the infrabasal plate 200, be provided with an insulation course (sheath) 204, for example constituted, shown in Fig. 2 a by organic material or silicon nitride.

Memory capacitance 202 is arranged between the insulation course 204 of infrabasal plate 200 and pixel electrode 206 belows (shown in Fig. 2 a), and is positioned at the center section (as shown in Figure 1) of pixel region 200a.Memory capacitance 202 comprises: a bottom electrode 202a, a capacitance dielectric layer 202b, an and top electrode 202c, wherein top electrode 202c is the contact hole 204a that sees through in the insulation course 204, and electrically connects with the pixel electrode 206 of top.In the present embodiment, bottom electrode 202a is bar shaped, and the slit 206a of pixel electrode 206 has an inclination angle with respect to bottom electrode 202a.For example, slit 206a be a V-arrangement and with bar shaped bottom electrode 202a as an axis of symmetry.Moreover, have an overlapping district 207 between bottom electrode 202a and the slit 206a.Capacitance dielectric layer 202b is arranged on the bottom electrode 202a, and top electrode 202c, is arranged on the capacitance dielectric layer 202b of bottom electrode 202a top.In the present embodiment, top electrode 202c has at least one depressed area 205, exposes the district 207 that overlaps with the part.For example, top electrode 202c has a pair of depressed area 205, and wherein the width of depressed area 205 is not less than the width of this slit 206a, shown in Fig. 2 a.In another embodiment, the width of depressed area 205 also can be less than the width of slit 206a, shown in Fig. 2 b.The width that is noted that slit 206a needs greater than 3 μ m.

Upper substrate 210 for example is to be made of clear glass or quartzy institute, and it is arranged at infrabasal plate 200 tops, and has at least one teat 210a and be parallel alternately row with the slit 206a of pixel electrode 206 and put.Liquid crystal layer 208 is arranged between infrabasal plate 200 and the upper substrate 210.

In the present embodiment, because top electrode 202c has depressed area 205, thereby can significantly reduce top electrode 202c area in the overlapping district 207 between bottom electrode 202a and slit 206a.Therefore, overlap that can not have same potential because of the top electrode 202c of pixel electrode 206 and memory capacitance 202 ineffective fully and cause the generation of disclination line for slit 206a in the district 207.Thus, the brightness that can improve display according to dot structure of the present invention descends and problem such as response time (response time) increase.Moreover, can improve the color offset phenomenon at contiguous memory capacitance 202 places and promote the image quality of display.

Fig. 3 is the planimetric map that shows the dot structure that is applicable to wide-angle liquid crystal display according to an embodiment of the invention, and wherein identical with Fig. 1 parts use identical label to represent and omit the explanation of being correlated with.The difference of the embodiment of Fig. 3 and the embodiment of Fig. 1 is the shape of slit 206a.In the present embodiment, the slit 206a of pixel electrode 206 has an inclination angle with respect to bottom electrode 202a and slit 206a is a bar shaped.

Fig. 4 is the planimetric map that shows the dot structure that is applicable to wide-angle liquid crystal display according to an embodiment of the invention, and wherein identical with Fig. 1 parts use identical label to represent and omit the explanation of being correlated with.The difference of the embodiment of Fig. 4 and the embodiment of Fig. 1 is that it is two parts that overlapping district 207 opens top electrode 202c.That is the top electrode 202c of 207 tops, district that overlap has a gap, make V-arrangement overlap district 207 fully or the part expose, only show situation that exposing the district 207 that overlaps fully herein.Thus, it is ineffective and cause the generation of disclination line that the slit 206a that is positioned at the district 207 that overlaps can not have same potential because of the top electrode 202c of pixel electrode 206 and memory capacitance 202.Be noted that,,, make the top electrode 202c of each separation and pixel electrode 206 electrically connect so must in insulation course 204, form extra contact hole 204b because top electrode 202c is split up into two parts fully.That is, corresponding at least one contact hole 204a of the top electrode 202c of each part or 204b.

Fig. 5 is the planimetric map that shows the dot structure that is applicable to wide-angle liquid crystal display according to an embodiment of the invention, and wherein identical with Fig. 4 parts use identical label to represent and omit the explanation of being correlated with.The difference of the embodiment of Fig. 5 and the embodiment of Fig. 4 is the shape of slit 206a.In the present embodiment, the slit 206a of pixel electrode 206 has an inclination angle with respect to bottom electrode 202a and slit 206a is a bar shaped.Similarly, top electrode 202c is split up into two parts fully, make bar shaped overlap district 207 fully or the part expose.Similarly, only show the situation of exposing the district 207 that overlaps fully herein.Therefore, need in the insulation course 204 to form extra contact hole 204b, make the top electrode 202c of each separation and pixel electrode 206 electrically connect.

Though the present invention discloses as above with preferred embodiment; right its is not in order to limit the present invention; any those skilled in the art; under the premise without departing from the spirit and scope of the present invention; can make various modifications and variations, so protection scope of the present invention is as the criterion when looking the claims person of defining.

Claims

1. A pixel structure suitable for a wide viewing angle liquid crystal display, comprising:

a substrate, which has a pixel area;

a pixel electrode, disposed above the pixel area, has at least one slit; and

A storage capacitor is arranged between the substrate and the pixel electrode, which includes:

a lower electrode, disposed in the pixel area of the substrate, has an overlapping area with the slit;

a capacitive dielectric layer disposed on the lower electrode; and

An upper electrode is arranged on the capacitive dielectric layer above the lower electrode and is electrically connected with the pixel electrode. The upper electrode has at least one recessed area to partially expose the overlapping area.

2. The pixel structure suitable for a wide viewing angle liquid crystal display as claimed in claim 1, wherein the width of the recessed area is not smaller than the width of the slit.

3. The pixel structure suitable for a wide viewing angle liquid crystal display as claimed in claim 1, wherein the width of the recessed area is smaller than the width of the slit.

4. The pixel structure suitable for a wide viewing angle liquid crystal display as claimed in claim 1, wherein the bottom electrode is strip-shaped, and the slit has an inclination angle relative to the strip-shaped bottom electrode.

5 . The pixel structure suitable for a wide-viewing-angle liquid crystal display as claimed in claim 4 , wherein the slit is V-shaped and uses the strip-shaped bottom electrode as a symmetry axis. 5 .

6 . The pixel structure suitable for wide viewing angle liquid crystal display as claimed in claim 4 , wherein the upper electrode has a pair of recessed regions to partially expose the overlapping regions respectively.

7. The pixel structure applicable to a wide viewing angle liquid crystal display as claimed in claim 1, further comprising an insulating layer disposed between the pixel electrode and the storage capacitor, which has a contact window to electrically connect the pixel electrode with the upper electrode.

8. The pixel structure suitable for a wide viewing angle liquid crystal display as claimed in claim 1, wherein the lower electrode is disposed in a middle portion of the pixel area.

9. A pixel structure suitable for a wide viewing angle liquid crystal display, comprising:

a substrate, which has a pixel area;

a pixel electrode, disposed above the pixel area, has at least one slit; and

a capacitive dielectric layer disposed on the lower electrode; and

At least two upper electrodes are arranged on the capacitive dielectric layer above the lower electrode and are electrically connected with the pixel electrode, and the upper electrodes are separated by the overlapping area.

10. The pixel structure suitable for a wide viewing angle liquid crystal display as claimed in claim 9, wherein the bottom electrode is strip-shaped, and the slit has an inclination angle relative to the strip-shaped bottom electrode.

11. The pixel structure suitable for a wide viewing angle liquid crystal display as claimed in claim 10, wherein the slit is V-shaped and uses the strip-shaped bottom electrode as a symmetry axis.

12. The pixel structure suitable for a wide viewing angle liquid crystal display as claimed in claim 9, further comprising an insulating layer disposed between the pixel electrode and the storage capacitor, having at least two contact windows to electrically connect the pixel electrodes and the upper electrodes.

13. The pixel structure suitable for a wide viewing angle liquid crystal display as claimed in claim 9, wherein the lower electrode is disposed in a middle portion of the pixel area.