CN1696804A - Liquid-crystal displaying apparatus - Google Patents

Abstract

A first substrate includes, on one side thereof that is closer to a liquid crystal layer, a picture element electrode provided for each picture element region, a switching element, and a bus line. A second substrate includes a counter electrode opposing the picture element electrode. The picture element electrode includes a plurality of openings and a solid portion that includes a plurality of unit solid portions. In each picture element region, the liquid crystal layer takes a vertical alignment in the absence of an applied voltage, and forms a plurality of liquid crystal domains, each of which takes a radially-inclined orientation, in the plurality of openings and the solid portion by inclined electric fields produced at respective edge portions of the plurality of openings of the picture element electrode in response to an applied voltage. In each picture element region, at least one of the plurality of openings of the picture element electrode that is located along the bus line and located between two adjacent ones of the plurality of unit solid portions is superposed on the bus line.

Description

Liquid crystal indicator

The present patent application be the present patent application people on November 30th, 2002 submit to, application number is 02140006.7, denomination of invention is divided an application for the patent application of " liquid crystal indicator ".

Technical field

The present invention relates to a kind of liquid crystal indicator, relate in particular to a kind of wide viewing angle characteristics and can produce the liquid crystal indicator of high-quality demonstration of having.

Background technology

Recent years, thin and lightweight liquid crystal indicator is as personal computer monitor and PDA (personal digital assistant) display.Yet traditional twisted nematic (TN) type and STN Super TN (STN) type liquid crystal indicator have narrow visual angle.Adopted various technological development to solve this problem.

The typical technology that is used to improve TN type or STN type liquid crystal indicator viewing angle characteristic is to increase an optical compensation plate (optical compensation plate) thereon.Another kind method is to use lateral electric field mode, wherein a horizontal component of electric field with respect to substrate plane is added on the liquid crystal layer.The liquid crystal indicator of lateral electric field mode arouses public attraction, and recent years is by large-scale production.Another method is to use DAP (vertically aligned phase place distortion) pattern, and the nematic liquid crystal material that wherein has negative dielectric anisotropic is as a kind of liquid crystal material, and the perpendicular alignmnet film is as a kind of aligning film.This is a kind of ECB (electrically conerolled birefringence) pattern formula, wherein controls transmission by the birefringence of using liquid crystal molecule.

Though lateral electric field mode is a kind of effective ways that improve the visual angle, but compare with general T N type device, its production technology causes obviously low production leeway, thus, is difficult to the steady production of implement device.This is because display brightness or contrast ratio are subjected to the obvious influence that the gap changes or polarization plates transmission axle (polarization axle) is offset on direction with respect to the liquid crystal molecular orientation axle between the substrate.Also need technological development so that can accurately control these factors, the steady production of implement device thus.

For the DAP mode LCD, do not show heterogeneity in order to realize evenly showing, need to aim at control.For example control by using friction that registration process is carried out on the aligning film surface, can provide to aim at.Yet when the perpendicular alignmnet film was subjected to friction treatment, the friction streak may appear in the image of demonstration, and it is not suitable for large-scale production.

This area proposes another kind ofly to be used to aim at control and without the method for friction treatment, it is to form slit (opening) so that produce tilting electric field and the direction of orientation (for example, 6-301036 and 2000-47217 number Japan's special permission publication document) by tilting electric field control liquid crystal molecule in electrode.Yet, the inventor has studied these open source literatures and has found, use wherein disclosed method, can not limit corresponding to the orientation in the liquid crystal layer region of electrode split shed, thus, the orientation of liquid crystal molecule is not fully continuous, on each pixel, be difficult to realize stable orientations, cause non-homogeneous demonstration.

Consider this, the invention tissue that comprises some people of the present invention proposes another kind of method (Japanese patent application No. 2000-244648), wherein, the predetermined electrode structure that comprises opening and solid portion is formed on in a pair of substrate one, they are relative mutually via liquid crystal layer therebetween, by tilting electric field a plurality of liquid crystal territory of getting radial skew orientation respectively is formed in opening and the solid portion thus, this electric field is created in separately on the edge of opening part.

Yet the inventor has been found that and only passes through to be provided with as disclosed electrode structure in this patented claim, can not fully improve display quality.This is that (here, term " bus " is used for collective and calls one group of interconnection line) applies orientation adjusting power because near the electric field that produces the bus edge, and it does not match with the orientation adjusting power that the tilting electric field that partly produces at edge of opening applies.

Summary of the invention

The present invention has solved the problems of the prior art, the purpose of this invention is to provide a kind of liquid crystal indicator with wide viewing angle characteristics and high display quality.

A plurality of pixel regions that a kind of liquid crystal indicator of the present invention comprises first substrate, second substrate, is arranged on the liquid crystal layer between first substrate and second substrate and is used to produce demonstration, it is characterized in that: described first substrate comprises each pixel electrode, the on-off element that is electrically connected to pixel electrode and the bus that is used for a plurality of pixel regions at it near side of liquid crystal layer, described bus comprises grid bus and the source bus line that is electrically connected to described on-off element; Described second substrate comprises and sets off by contrast at the end (counter substrate) that it is relative with pixel electrode via described liquid crystal layer; Described pixel electrode comprises a plurality of openings and a solid portion, and described solid portion comprises a plurality of units solid portion (unit solid portion); In each of a plurality of pixel regions, when not having impressed voltage between pixel electrode and the counter electrode, the liquid crystal layer perpendicular alignmnet, and, by a tilting electric field, in these a plurality of openings and this solid portion, form a plurality of liquid crystal territory, the impressed voltage between response pixel electrode and the counter electrode and on each marginal portion of a plurality of openings of pixel electrode, produce described tilting electric field; In a plurality of liquid crystal territory each is got the radial skew orientation, and the orientation of each in a plurality of liquid crystal territory changes according to impressed voltage, produces thus to show; In each of a plurality of pixel regions, at least one is stacked on the described bus in a plurality of pixel electrode openings, and it is along between bus arrangement and in a plurality of units solid portion adjacent two.Thereby realized above-mentioned purpose.

A plurality of pixel regions that another kind of liquid crystal indicator of the present invention comprises first substrate, second substrate, is arranged on the liquid crystal layer between first substrate and second substrate and is used to produce demonstration, it is characterized in that: described first substrate comprises each pixel electrode, the on-off element that is electrically connected to pixel electrode and the bus that is used for a plurality of pixel regions at it near side of liquid crystal layer, described bus comprises grid bus and the source bus line that is electrically connected to described on-off element; Described second substrate comprises and setting off by contrast at the end that it is relative with pixel electrode via described liquid crystal layer; Described pixel electrode comprises a plurality of openings and a solid portion, and described solid portion comprises a plurality of units solid portion, and each unit solid portion is surrounded by at least some openings in a plurality of openings; When not having impressed voltage between pixel electrode and the counter electrode, the liquid crystal layer perpendicular alignmnet; In each of a plurality of pixel regions, at least one is stacked on the described bus in a plurality of openings of pixel electrode, and it is along between bus arrangement and in a plurality of units solid portion adjacent two.Thereby realized above-mentioned purpose.

Preferably, described at least one opening that is stacked on the bus comprises the opening of arranging along grid bus at least.

Can all be stacked on the bus along some openings in a plurality of openings of grid bus arranged pixel electrodes.

Described at least one opening that is stacked on the bus can also comprise the opening of arranging along source bus line.

Preferably, at least some openings in a plurality of openings have substantially the same shape and substantially the same size, and form at least one cell (lattice), arrange described cell and make rotation symmetrical.

Preferably, the shape of each of at least some openings in a plurality of openings is all rotated symmetry.

Each of at least some openings in a plurality of openings can have general circle.

Each of a plurality of units solid portion can have general circle.

Preferably, in each of a plurality of pixel regions, a plurality of opening total areas of pixel electrode are less than pixel electrode solid portion area.

Liquid crystal indicator can also comprise that at a plurality of openings one is outstanding in each, in first substrate plane, shape of cross section that should be outstanding is identical with the shape of cross section of a plurality of openings, outstanding side has about the orientation of the liquid crystal molecule of liquid crystal layer regulates power, and its direction is identical with the orientation adjusting direction of tilting electric field.

A plurality of pixel regions that another kind of again liquid crystal indicator comprises first substrate, second substrate, is arranged on the liquid crystal layer between first substrate and second substrate and is used to produce demonstration, it is characterized in that: described first substrate comprises each pixel electrode, the on-off element that is electrically connected to pixel electrode and the bus that is used for a plurality of pixel regions at it near side of liquid crystal layer, described bus comprises grid bus and the source bus line that is electrically connected to described on-off element; Described second substrate comprises and setting off by contrast at the end that it is relative with pixel electrode via described liquid crystal layer; Described pixel electrode comprises a plurality of openings and a solid portion; In each of a plurality of pixel regions, when not having impressed voltage between pixel electrode and the counter electrode, the liquid crystal layer perpendicular alignmnet, and, the orientation of liquid crystal layer is regulated by a tilting electric field, the impressed voltage of response between pixel electrode and counter electrode produces described tilting electric field on the respective openings marginal portion in a plurality of openings of pixel electrode; In each of a plurality of pixel regions, at least one is covered by the pixel electrode solid portion in grid bus edge and the source bus line edge.Thereby realized above-mentioned purpose.

Preferably, in each of a plurality of pixel regions, the grid bus edge is covered by the pixel electrode solid portion at least.

In each of a plurality of pixel regions, grid bus edge and source bus line edge can all be covered by the pixel electrode solid portion.

The pixel electrode solid portion can comprise a plurality of units solid portion; In each of a plurality of pixel regions, by a tilting electric field, in a plurality of openings and this solid portion, liquid crystal layer can form a plurality of liquid crystal territory, the impressed voltage between response pixel electrode and the counter electrode and produce described tilting electric field on each marginal portion of a plurality of openings of pixel electrode; In a plurality of liquid crystal territory each is got the radial skew orientation, and the orientation of each in a plurality of liquid crystal territory changes according to impressed voltage, produces thus to show.

In each of a plurality of pixel regions, at least one can be stacked on the described bus in a plurality of openings of pixel electrode, and it is along between bus arrangement and in a plurality of units solid portion adjacent two.

When impressed voltage occurring between pixel electrode and the counter electrode, by tilting electric field, along in the part solid portion of bus arrangement, liquid crystal layer can form the part liquid crystal territory of getting the radial skew orientation.

Now function of the present invention will be described.

In liquid crystal indicator of the present invention, be used for providing on the liquid crystal layer to each pixel region the pixel electrode of voltage to comprise a plurality of openings (the electrode part that does not have conducting film) and solid portion (just there is the conducting film part in the electrode part except opening).Solid portion comprises a plurality of units solid portion, and each unit solid portion is surrounded by opening basically, makes with the continuous conduction film usually.When not having impressed voltage, liquid crystal layer is got vertical orientated, yet, when having impressed voltage,, forming a plurality of liquid crystal territory of getting the radial skew orientation by a tilting electric field, this tilting electric field is created on the marginal portion separately of pixel electrode opening.Usually, liquid crystal layer is with a kind of liquid crystal material manufacturing with negative dielectric anisotropic, and the orientation of liquid crystal layer is controlled by the perpendicular alignmnet film, and it is arranged on the opposite flank of liquid crystal layer.

With pixel electrode opening and the corresponding zone of solid portion in, form the liquid crystal territory by tilting electric field, the orientation in each liquid crystal territory changes according to impressed voltage, produces thus to show.Because the rotational symmetry orientation is got in each liquid crystal territory, there is the view angle dependency of display quality seldom, thereby realizes wide viewing angle characteristics.

And, all pass through tilting electric field formation with opening corresponding liquid crystal territory with solid portion corresponding liquid crystal territory, this tilting electric field is created on the edge of opening part, these liquid crystal territories are adjacent to be formed in the alternating pattern mutually thus, and liquid crystal molecular orientation is basically mutually continuously in liquid crystal molecular orientation and another adjacent lcd territory in the liquid crystal territory.Therefore, be formed on the liquid crystal territory in the opening and be formed between another adjacent lcd territory in the solid portion and do not form the swing offset line, thus, the display quality of not degenerating, and liquid crystal molecular orientation is highly stable.

In liquid crystal indicator of the present invention, not only with the corresponding zone of pixel electrode solid portion in, and with the corresponding zone of pixel electrode opening in, liquid crystal molecule is got radial skew orientation.Compare with above-mentioned traditional liquid crystal indicator, for such liquid crystal indicator, when realizing stable orientations, the continuity of liquid crystal molecular orientation is higher.Can evenly be shown thus and do not shown heterogeneity.Especially, for the response characteristic (high response speed) of realizing ideal, the tilting electric field that is used to control liquid crystal molecular orientation need act on a large amount of liquid crystal molecules.For this reason, need to form a large amount of openings (marginal portion).In liquid crystal indicator of the present invention,, form liquid crystal territory with stable radial skew orientation for each opening.Therefore, even form a large amount of openings in order to improve response characteristic, the reduction of display quality (heterogeneity occurring showing) also can be inhibited.

Yet, only, can not fully improve display quality by above-mentioned electrode structure is provided, this depends on the position relation between pixel electrode opening and bus (the one group of interconnection line) edge.

Because the prearranged signals (voltage) that is used to drive liquid crystal indicator is applied to the bus of liquid crystal indicator, produces electric field between bus and counter electrode.Therefore, near the bus edge, produce tilting electric field.Yet the orientation of this tilting electric field is regulated power and is not matched with the orientation adjusting power that is created in the tilting electric field on the edge of opening part.Therefore, if along the liquid crystal territory that forms in the opening of bus arrangement, the orientation that is subjected near the tilting electric field in bus edge is regulated power, and the orientation in liquid crystal territory is interfered, and causes the radial skew orientation of being out of shape thus.And, keep orientation continuity between them owing to preset the adjacent lcd territory, the orientation in orientation disturbing effect adjacent lcd territory, the just orientation in the liquid crystal territory of adjacent cells solid portion.Therefore, the liquid crystal territory of each adjacent cells solid portion orientation is interfered.

Get in the liquid crystal territory of radial skew orientation of distortion in the orientation of being disturbed owing to it, this orientation is unstable and damage easily, thus, apply after the voltage, the orientation in this liquid crystal territory reach to spend before the steady state (SS) long-time.Like this, aforesaid orientation is disturbed and is caused response speed to reduce (response characteristic degeneration).

And each the liquid crystal territory in the pixel region reaches the steady state (SS) of the radial skew orientation with this distortion, and wherein orientation is interfered, and the orientation of being disturbed changes to another from a pixel region.Therefore, persistence of vision may occur, wherein, after the image switching signal input, the image residue that shows previously.This is that transmission also changes between the different pixels district because if aligned liquid crystal layer changes between the different pixels district.Especially, be transformed into the pixel region that intermediate grey scales shows and be transformed between the pixel region that intermediate grey scales shows showing from black display from white, there is marked difference in aligned liquid crystal layer, and the transmission difference between the pixel region may be observed to persistence of vision like this.This is because underlying cause.In white showed, the tilting electric field that is created on the edge of opening part applied strong relatively orientation adjusting power, and thus, aligned liquid crystal layer is stable.Therefore, even be transformed into after the intermediate grey scales demonstration, aligned liquid crystal layer is stable.On the other hand, when being transformed into intermediate grey scales from black display and showing, aligned liquid crystal layer may damage because be created in the orientation of the tilting electric field on the edge of opening part regulate power relatively a little less than.

Liquid crystal indicator of the present invention is designed to like this, and in each of a plurality of pixel regions, at least one is stacked on the bus (strictly saying a part of bus) in a plurality of openings, and it is along bus arrangement and between two adjacent cells solid portions.Therefore, near the bus edge of opening that is stacked on the bus is covered by the unit solid portion of pixel region.

Therefore, near the opening that is stacked on the bus, the liquid crystal molecule of liquid crystal layer obtains electric shield by the unit solid portion of pixel region, exempts near the influence of the tilting electric field that produces the bus edge.Therefore, the liquid crystal molecule of liquid crystal layer does not suffer an orientation adjusting power effect, and this orientation adjusting power is come near the tilting electric field that produces in comfortable bus edge, and its orientation is only regulated by the tilting electric field that results from the edge of opening part.Therefore, in liquid crystal indicator of the present invention, in the liquid crystal territory that forms in the opening on being stacked in bus, or in the liquid crystal territory that in the unit solid portion adjacent, forms with opening, orientation is interference-free, thus, has suppressed response speed reduction (response characteristic degeneration) and persistence of vision and has occurred.

Disturb for the orientation that suppresses to cause, preferably, increase the opening ratio that is stacked on the bus, just increase the bus marginal portion that is covered by the unit solid portion of pixel region owing near the tilting electric field that is created in the bus edge.Yet under the situation with light blocking (light-blocking) made bus, the increase of this ratio may reduce the aperture ratio.Therefore, consider desirable response characteristic and aperture ratio, the application of dependence liquid crystal indicator etc. can suitably determine to be stacked in the opening ratio on the bus.

By using a kind of arrangement, can suppress response speed reduction and persistence of vision effectively occurs, in this is arranged, be arranged between two adjacent cells solid portions and be stacked in opening on the bus, at least comprise opening (just a kind of arrangement of arranging along grid bus, wherein along bus arrangement and be arranged among two openings between the adjacent cells solid portion, at least one opening of arranging along grid bus is stacked on the bus).This is because compare with source bus line, and big voltage is applied on the grid bus usually, thus, compares with near the tilting electric field being created in the source bus line edge, is created near the tilting electric field in grid bus edge liquid crystal molecule is had bigger influence.

In addition, not only be arranged in two openings between the adjacent cells solid portion, and can be stacked on the bus along other opening of bus arrangement.For example, among a plurality of openings of pixel electrode, all openings of arranging along grid bus can be stacked on the bus.

Certainly, can use alternative arrangement, for example a kind of arrangement wherein is arranged between two adjacent cells solid portions and is stacked in opening on the bus, comprises the opening of arranging along source bus line.

Note,, not only cause aforesaid response speed to reduce and persistence of vision as mentioned above though be created near the tilting electric field in bus edge as mentioned above, and cause contrast ratio to reduce, but as mentioned below, if bus photoresist manufacturing can suppress contrast ratio and reduce.

As mentioned above, near the bus edge, produce a tilting electric field,, all produce this tilting electric field no matter on the liquid crystal layer between pixel electrode and the counter electrode, there is/do not have impressed voltage.Therefore, producing in the liquid crystal indicator that shows with common black mode, if when not having impressed voltage, by near the liquid crystal molecule the orientation adjusting power inclination bus edge of tilting electric field, light leak may occur, and reduces contrast ratio thus.Especially, come the maintained switch element to turn-off because the grid bus most of the time applies high relatively voltage, near the grid bus edge, this light leak degree is tangible.

In liquid crystal indicator of the present invention, near the bus edge that is stacked in the opening on the bus, by the unit solid portion covering of pixel electrode, thus, the liquid crystal molecule of liquid crystal layer obtains electric shield, exempts from the influence that is created near the tilting electric field in bus edge.Therefore, the liquid crystal molecule of liquid crystal layer is not tilted the orientation adjusting power inclination of electric field.Can tilt by the electric field that is created between bus and the counter electrode although be stacked in the liquid crystal molecule of the liquid crystal layer in the opening on the bus, if but bus photoresist manufacturing is stacked in the opening resistance light on the bus.Therefore, in liquid crystal indicator of the present invention, suppressed the appearance of light leak, thus, if bus photoresist manufacturing has suppressed the contrast ratio reduction.

And, if bus photoresist manufacturing is as described below, may suppress the heterogeneity (localized variation of contrast ratio just) in the display plane, improve display quality thus.

Because be created near the tilting electric field the bus edge, residual charge may appear in the opening, by this opening, exposes insulating material, if because the influence of residual charge is tilted along the liquid crystal molecule in the opening of bus arrangement, it will cause light leak.Though the residual charge degree relies on the surface appearance of insulating material and changes, when not excessive print register film or injection liquid crystal material, changing appears in the insulating material surface appearance.Therefore, in liquid crystal indicator, there is variation in the residual charge in the display plane.If residual charge changes in the display plane, the light leak degree also changes in the display plane, causes the contrast ratio localized variation thus, thereby produces heterogeneity.Especially, as mentioned above, because high relatively voltage is applied to grid bus, grid bus obviously promotes heterogeneity to occur.

In liquid crystal indicator of the present invention, when bus was made with photoresist, the opening that is stacked on the bus was covered by bus, thus, had suppressed aforesaid heterogeneity and had occurred, and improved display quality thus.

When at least some openings in a plurality of openings have identical shaped and same size basically and form at least one when being arranged in rotational symmetric cell, for each cell, a plurality of liquid crystal territory height symmetric offset spread thus, may be improved the view angle dependency of display quality.And, by whole pixel region divided into unit lattice, may stablize the aligned liquid crystal layer on the whole pixel region.For example, can be arranged in opening like this, open centre forms a grid.Note, in opaque element each pixel region that for example storage capacitance line is cut apart, can be each the district's arrangement units lattice that promotes to show.

When each the shape of at least some openings in a plurality of openings (normally forming the opening of cell) has the rotation symmetry, may increase the stability of the liquid crystal territory radial skew orientation that is formed in the opening.For example, the shape of each opening (as observed from the substrate normal direction) can be circle or regular polygon (for example square).Note,, can use not have rotational symmetric shape (for example oval) according to (aspect ratios) such as shapes of pixel.And, when the shape in the solid portion that is surrounded by opening basically (" unit solid portion ") zone has the rotation symmetry, may increase the stability of the liquid crystal territory radial skew orientation that is formed in the solid portion.For example, when aperture arrangement was in a chequer, opening shape can be general star or cruciform, and the solid portion shape can be general circle, general square or the like.Certainly, opening and the solid portion that surrounded by opening basically can have general square.

For the stable liquid crystal territory radial skew orientation that is formed in the electrode opening, preferably, the liquid crystal territory that is formed in the opening has general circle.In other words, opening shape can be designed to like this, and the liquid crystal territory that is formed in the opening has general circle.

Certainly, for the stable liquid crystal territory radial skew orientation that is formed in the electrode solid portion, preferably, the solid portion zone that is surrounded by opening has general circle basically.Corresponding with the solid portion zone that is surrounded by a plurality of openings basically (unit solid portion), be formed on the continuous conduction film and make the liquid crystal territory that forms in the solid portion.Therefore, the shape of opening and arrangement can be defined as like this, and solid portion zone (unit solid portion) has general circle.

For above-mentioned any alternative, preferably, be formed on the interior opening total area of electrode less than the solid portion area in each pixel region.Along with the solid portion area increases, liquid crystal layer area (as observed from the substrate normal direction, being defined in the liquid crystal layer plane) increases, the electric field that electrode produces directly influences this liquid crystal layer, thus, with respect to the voltage that is applied on the liquid crystal layer, improve optical characteristics (for example transmission).

Preferably, the arrangement of each opening of the general circle of use also is to use the arrangement of each unit solid portion of general circle, and is bigger and definite by the solid portion area of determining its arrangement.More preferably, rely on pel spacing suitably to select more preferably which kind of arrangement.Usually, when spacing during, preferably, form opening and make each solid portion have general circle greater than about 25 μ m.When spacing was less than or equal to about 25 μ m, preferably, each opening had general circle.

When having only the impressed voltage of existence, the orientation of a tilting electric field is regulated power and is just occurred, and this tilting electric field produces on the edge of opening part that is formed in the above-mentioned electrode.Therefore, when not having impressed voltage or low relatively voltage occurring, for example,, can not keep the radial skew orientation in liquid crystal territory if there is a stress to be applied on the liquid crystal board.In order to address this problem, the liquid crystal indicator of one embodiment of the invention comprises that in each electrode opening one is outstanding, and this outstanding side has orientation adjusting power, and its direction about the liquid crystal layer liquid crystal molecule is identical with the direction of the orientation adjusting of above-mentioned tilting electric field.Preferably, on the substrate plane direction, outstanding shape of cross section is identical with opening shape, and having the rotation symmetry with above-mentioned opening shape, the same to have a rotation symmetrical.

Use liquid crystal indicator of the present invention, only by opening being provided and, may realizing stable radial skew orientation by to arrange each pixel electrode opening with the predetermined location relationship at bus edge in each pixel electrode.Especially, can produce liquid crystal indicator of the present invention by known production technology, this method is that pattern-making makes in its step that becomes pixel electrode to conducting film at handle, by revising photomask, make the opening of ideal form be formed in the ideal alignment, with in step,, make bus form desired shapes by revising photomask to bus pattern-making.

In another liquid crystal indicator of the present invention, the edge of at least one is covered by the solid portion of pixel electrode in grid bus and the source bus line.Therefore, near the bus of its edge by the covering of pixel electrode solid portion, the liquid crystal molecule of liquid crystal layer obtains electric shield, exempts from the influence that is created near the tilting electric field in bus edge.Therefore, the liquid crystal molecule of liquid crystal layer is not tilted the orientation adjusting power inclination of electric field.Therefore, suppress the appearance of light leak, thus, suppressed the contrast ratio reduction.And, because the edge near zone that is covered by the pixel electrode solid portion covered by the conducting film of pixel electrode (solid portion), thus residual charge can not occur, thereby suppressed heteropical appearance.As mentioned above, in liquid crystal indicator of the present invention,, suppressed the contrast ratio reduction thus because the light leak that near the tilting electric field that produces the bus causes is inhibited, when the heterogeneity that causes owing near the residual charge bus is inhibited simultaneously, realized high-quality demonstration thus.

Owing to compare with near the tilting electric field that produces the source bus line edge, near the tilting electric field that produces the grid bus edge is bigger to the liquid crystal molecule influence, so preferably, the grid bus edge is covered by the pixel electrode solid portion at least.In addition, near the influence of the tilting electric field that suppresses more reliably to produce the bus edge, preferably by the edge of the solid portion overlies gate bus of pixel capacitors and the edge of source bus line.

In liquid crystal indicator of the present invention, suppressed owing to be created in the reduction of the display quality that near the tilting electric field the bus edge causes.Therefore, the invention provides a kind of liquid crystal indicator, it has wide viewing angle characteristics and high display quality.

The present invention goes for active array type LCD, and goes in transmissive liquid crystal display device, reflection-type liquid-crystal display device and transmission/combinations of reflections type liquid crystal indicator any one.

Description of drawings

Figure 1A and 1B schematically illustrate a pixel region structure according to the liquid crystal indicator 100 of the embodiment of the invention, and wherein Figure 1A is a planimetric map, and Figure 1B is the cross-sectional view along the line 1B-1B ' of Figure 1A.

Fig. 2 A and 2B illustrate the liquid crystal layer 30 that there is the liquid crystal indicator 100 of an impressed voltage at two ends, and wherein Fig. 2 A schematically illustrates an orientation and just begun the state (initial turn-on state) that changes, and Fig. 2 B schematically illustrates a stable state.

Each figure of Fig. 3 A-3D illustrates map to separate the relation between line of electric force and the liquid crystal molecular orientation.

It is viewed according to the liquid crystal molecular orientation in the liquid crystal indicator 100 of the embodiment of the invention that each figure of Fig. 4 A-4C illustrates map to separate along the substrate normal direction.

Fig. 5 A-5C schematically illustrates the exemplary radial skew orientation of liquid crystal molecule.

Fig. 6 A and 6B are the planimetric maps of other pixel electrode of using in the liquid crystal indicator that schematically is illustrated in according to the embodiment of the invention.

Fig. 7 A and 7B are still the planimetric map of other pixel electrode that uses in the liquid crystal indicator that schematically is illustrated in according to the embodiment of the invention.

Fig. 8 A and 8B are still the planimetric map of other pixel electrode that uses in the liquid crystal indicator that schematically is illustrated in according to the embodiment of the invention.

Fig. 9 is the planimetric map of another pixel electrode of using in the liquid crystal indicator that schematically is illustrated in according to the embodiment of the invention.

Figure 10 A and 10B are still the planimetric map of other pixel electrode that uses in the liquid crystal indicator that schematically is illustrated in according to the embodiment of the invention.

Figure 11 A schematically illustrates graphic pattern unit lattice among Figure 1A, and Figure 11 B schematically illustrates graphic pattern unit lattice among Fig. 9, and Figure 11 C is the curve map of relation between diagram spacing p and the solid portion area ratio.

Figure 12 is the planimetric map of schematically diagram according to a pixel region structure of the liquid crystal indicator 100 of the embodiment of the invention.

Figure 13 is the planimetric map of a pixel region structure of diagram liquid crystal indicator 700 schematically, and wherein the opening along bus arrangement does not overlap on the bus.

Figure 14 A and 14B schematically illustrate a parameatal liquid crystal molecular orientation, and this opening arranges that along the grid bus of liquid crystal indicator 700 wherein Figure 14 A is a planimetric map, and Figure 14 B is a cross-sectional view.

Figure 15 A is the cross-sectional view along the line 15A-15A ' of Figure 13, and Figure 15 B is the cross-sectional view along the line 15B-15B ' of Figure 13.

Figure 16 A and 16B schematically illustrate a parameatal liquid crystal molecular orientation, and this opening arranges that along the grid bus according to the liquid crystal indicator 100 of the embodiment of the invention wherein Figure 16 A is a planimetric map, and Figure 16 B is a cross-sectional view.

Figure 17 is the planimetric map of schematically diagram according to the pixel region structure of the liquid crystal indicator 100A of the embodiment of the invention.

Figure 18 is the planimetric map of schematically diagram according to the pixel region structure of the liquid crystal indicator 100B of the embodiment of the invention.

Figure 19 is the planimetric map of schematically diagram according to the pixel region structure of the liquid crystal indicator 100C of the embodiment of the invention.

Figure 20 is the planimetric map of schematically diagram according to the pixel region structure of the liquid crystal indicator 100D of the embodiment of the invention.

Figure 21 A is the planimetric map of schematically diagram according to the pixel region structure of the liquid crystal indicator 100E of the embodiment of the invention, and Figure 21 B is the enlarged drawing of grid bus peripheral part among diagram Figure 21 A.

Figure 22 A is the planimetric map of schematically diagram according to the pixel region structure of the liquid crystal indicator 100F of the embodiment of the invention, and Figure 22 B is the enlarged drawing of grid bus peripheral part among diagram Figure 22 A.

Figure 23 is the planimetric map of schematically diagram according to the pixel region structure of the liquid crystal indicator 100G of the embodiment of the invention.

Figure 24 A is the planimetric map of schematically diagram according to the pixel region structure of the liquid crystal indicator 100H of the embodiment of the invention, and Figure 24 B is the enlarged drawing of grid bus peripheral part among diagram Figure 24 A.

Figure 25 A is the planimetric map of schematically diagram according to the pixel region structure of the liquid crystal indicator 100I of the embodiment of the invention, and Figure 25 B is the enlarged drawing of canopy utmost point bus peripheral part among diagram Figure 25 A.

Figure 26 A and 26B schematically illustrate a pixel region structure of the liquid crystal indicator 200 of the alternate embodiment according to the present invention, and wherein Figure 26 A is a planimetric map, and Figure 26 B is the cross-sectional view along the line 26B-26B ' of Figure 26 A.

Figure 27 A-27D schematically illustrates liquid crystal molecule 30a orientation and has relation between the surface structure of perpendicular alignmnet power (verticalalignment power).

The liquid crystal layer 30 of liquid crystal indicator 200 when Figure 28 A and 28B illustrate two ends impressed voltage is arranged, wherein Figure 28 A schematically illustrates orientation and has just begun the state (initial turn-on state) that changes, and Figure 28 B schematically illustrates stable state.

Figure 29 A-29C is liquid crystal indicator 200A, the 200B of respectively schematically diagram alternate embodiment and the cross-sectional view of 200C, they have opening and outstanding between the diverse location relation.

Figure 30 is the cross-sectional view of schematically diagram along the liquid crystal indicator 200 of the line 30A-30A ' of Figure 26 A.

Figure 31 A and 31B schematically illustrate the pixel region structure of the liquid crystal indicator 200D of the alternate embodiment according to the present invention, and wherein Figure 31 A is a planimetric map, and Figure 31 B is the cross-sectional view along the line 31B-31B ' of Figure 31 A.

Figure 32 A-32C is the cross-sectional view of a pixel region of the liquid crystal indicator 300 of schematically diagram with two-layer electrode, wherein Figure 32 A illustrates the state that does not have impressed voltage, Figure 32 B schematically illustrates orientation and has just begun the state (initial turn-on state) that changes, and Figure 32 C schematically illustrates stable state.

Figure 33 A and 33B schematically are illustrated in a cross-sectional view that sets off by contrast the pixel region that an outstanding liquid crystal indicator 400 is arranged at the end, and wherein Figure 33 A is a planimetric map, and Figure 33 B is the cross-sectional view along the line 33B-33B ' of Figure 33 A.

Figure 34 A-34C is the cross-sectional view of a pixel region of diagram liquid crystal indicator 400 schematically, wherein Figure 34 A illustrates the state that does not have impressed voltage, Figure 34 B schematically illustrates orientation and has just begun the state (initial turn-on state) that changes, and Figure 34 C schematically illustrates stable state.

Figure 35 schematically is illustrated in one to set off by contrast the planimetric map of the pixel region structure that another a liquid crystal indicator 400A that gives prominence to is arranged at the end.

Figure 36 schematically is illustrated in one to set off by contrast the planimetric map of the pixel region structure that another a liquid crystal indicator 400B that gives prominence to is arranged at the end.

Figure 37 schematically is illustrated in one to set off by contrast the planimetric map of the pixel region structure that another a liquid crystal indicator 400C that gives prominence to is arranged at the end.

Figure 38 A and 38B schematically illustrate a pixel region structure of the liquid crystal indicator 500 of another alternate embodiment according to the present invention, and wherein Figure 38 A is a planimetric map, and Figure 38 B is the cross-sectional view along the line 38B-38B ' of Figure 38 A.

Figure 39 is the planimetric map of diagram liquid crystal indicator 800 schematically, and wherein the part of grid pole edge of bus is not covered by the solid portion of pixel region.

Figure 40 is the planimetric map of a pixel region structure of the liquid crystal indicator 500A of schematically diagram another alternate embodiment according to the present invention.

Figure 41 is the planimetric map of a pixel region structure of the liquid crystal indicator 500B of schematically diagram another alternate embodiment according to the present invention.

Embodiment

Referring now to figure embodiments of the invention are described.

At first, will the electrode structure and the function thereof of liquid crystal indicator of the present invention be described.Hereinafter will the preferred embodiments of the present invention be described about the active array type LCD that uses thin film transistor (TFT) (TFT).And, though will the preferred embodiment of the present invention be described about transmission liquid crystal display device, as selection, the present invention can use reflective LCD device or transmission/combinations of reflections formula liquid crystal indicator.

Notice that in this manual will be referred to as " pixel region " with the zone of " pixel " corresponding liquid crystal display device, it is the least unit that shows.In color liquid crystal display arrangement, corresponding one " pixel (pixel) " of R, G and B " pixel ".In active array type LCD, pixel region is defined with the counter electrode relative with pixel electrode by pixel electrode.In structure with black matix (matrix), say that strictly pixel region is each regional part, apply voltage according to the show state of expecting at its two ends, the opening of this state and black matix is corresponding.

To a pixel region structure according to the liquid crystal indicator 100 of the embodiment of the invention be described with reference to Figure 1A and 1B.In the following description, for easy, color filter and black matix have been ignored.In addition, in subsequent figure, have with liquid crystal indicator 100 in each element of the substantially the same function of respective element will represent with identical Reference numeral, and below this element will be described no longer.Figure 1A is as viewed planimetric map on the substrate normal direction, and Figure 1B is the cross-sectional view along the line 1B-1B ' of Figure 1A.Figure 1B illustrates the state that the liquid crystal layer two ends do not have impressed voltage.

Liquid crystal indicator 100 comprises that an active matrix substrate (hereinafter being called " TFT substrate ") 100a, sets off by contrast at the end (being also referred to as " color filter substrate ") 100b and and is arranged on TFT substrate 100a and sets off by contrast liquid crystal layer 30 between the end 100b.As shown in Figure 1B, when not having impressed voltage by perpendicular alignmnet film (not shown) liquid crystal layer 30 two ends, the liquid crystal molecule 30a of liquid crystal layer 30 has negative dielectric anisotropic, and aim at perpendicular to the surface of perpendicular alignmnet film, be arranged on TFT substrate 100a and setting off by contrast on each the surface of end 100b as vertical alignment layer near liquid crystal layer 30.This state description is vertically aligned liquid crystal layer 30.Yet, notice that the liquid crystal molecule 30a of vertically aligned liquid crystal layer 30 can favour the normal on perpendicular alignmnet film surface (substrate surface) slightly, this depends on the perpendicular alignmnet film type or the liquid crystal material type of use.Usually, perpendicular alignmnet is defined as a kind of state, is orientated on about 85 ° of angles or bigger angle with respect to perpendicular alignmnet film surface at liquid crystal molecule axle under this state (be also referred to as " axle orientation ").

The TFT substrate 100a of liquid crystal indicator 100 comprises that a transparent substrates (for example glass substrate) 11 and is arranged on transparent substrates 11 lip-deep pixel electrodes 14.Set off by contrast end 100b and comprise that a transparent substrates (for example glass substrate) 21 and is arranged on transparent substrates 21 lip-deep counter electrodes 22.For each pixel region, the orientation of liquid crystal layer 30 changes according to the voltage that provides between pixel electrode 14 and the counter electrode 22, laying out pixel electrode 14 with counter electrode 22 so that relative mutually via liquid crystal layer 30.Show that by utilizing a kind of phenomenon to produce this phenomenon is exactly that the light polarization or the light quantity of passing liquid crystal layer 30 change along with the change in orientation of liquid crystal layer 30.

The pixel electrode 14 of liquid crystal indicator 100 comprises a plurality of opening 14a and a solid portion 14b.The part and the solid portion 14b that have removed conducting film in the pixel electrode 14 that opening 14a represents to be made by conducting film (for example ITO film) represent its part, have conducting film (part except opening 14a) here.Though for each pixel electrode, form a plurality of opening 14a, but solid portion 14b is basically by single continuous conduction film production.

Arrange openings 14a makes and is formed centrally grid in its each, the solid portion 14b ' of unit (be defined as a part of solid portion 14b that is surrounded by four opening 14a basically, these four openings are centered close to four lattice points that form a cell separately) has general circle.Each opening 14a has general star, and it has four quadrant arc-shaped side edges (edge), and has quadruple turning axle (four-folded rotation axis) at four side centers.In order to stablize the orientation of whole pixel region, preferably there is the periphery that reaches pixel electrode 14 in cell.Specifically, as shown in the figure, the periphery of pixel electrode 14 preferably is patterned into the corresponding shape of general half part opening 14a (in the periphery of pixel electrode 14 sides) or is processed into and general 1/4th corresponding shapes of opening 14a (in the periphery on 14 jiaos of the pixel electrodes), and the periphery along pixel electrode 14 also provides opening 14a thus.

The opening 14a that is arranged in the pixel region core is of similar shape and size usually.It is normally circular to lay respectively at the solid portion 14b ' of unit in the cell that is formed by opening 14a, and is of similar shape usually and size.Each solid portion 14b ' of unit is connected to the adjacent solid portion 14b ' of unit, forms solid portion 14b thus, and it plays single conducting film effect basically.

When between pixel electrode 14 with structure as mentioned above and the counter electrode 22 during impressed voltage, on the marginal portion of each opening 14a, produce tilting electric field, produce a plurality of liquid crystal territory thus, each territory has the orientation of radial skew.Producing the liquid crystal territory in each district accordingly with corresponding each district of opening 14a with the solid portion 14b ' of unit in the cell.

Have foursquare pixel electrode 14 though illustrate here, but the shape of pixel electrode 14 is not limited to this.The typical shape of pixel electrode 14 can be approximated to be rectangular shape (comprising square and rectangle), and opening 14a can fitly be arranged in wherein by a grid square pattern thus.Even when pixel electrode 14 has shape except rectangle,, just can obtain effect of the present invention as long as the liquid crystal territory is formed in the All Ranges in the pixel region with the mode aligned openings 14a of rule (for example with graphic grid square pattern) here.

To the mechanism that be formed the liquid crystal territory by above-mentioned tilting electric field be described with reference to figure 2A and 2B.Each figure of Fig. 2 A and 2B illustrates graphic liquid crystal layer 30 among alive Figure 1B thereon.Fig. 2 A schematically illustrates according to being applied to the voltage at liquid crystal layer 30 two ends, and liquid crystal molecule 30a orientation has just begun the state (initial turn-on state) that changes.Fig. 2 B schematically illustrates according to impressed voltage, and liquid crystal molecule 30a orientation has changed and become stable status.Curve EQ among Fig. 2 A and Fig. 2 B represents equipotential line.

Graphic as institute among Figure 1A, when pixel electrode 14 and counter electrode 22 are positioned at same potential (state of voltage is not provided on liquid crystal layer 30), the liquid crystal molecule 30a in each pixel region aims at perpendicular to the surface of substrate 11 and 21.

When impressed voltage on liquid crystal layer 30, produced potential gradient by the expression of the equipotential line EQ (perpendicular to line of electric force) shown in Fig. 2 A.Equipotential line EQ is parallel to the solid portion 14b in the liquid crystal layer 30 and the surface of counter electrode 22, and liquid crystal layer 30 and descends in the corresponding zone of opening 14a of equipotential line EQ and pixel electrode 14 between the solid portion 14b and counter electrode 22 of pixel electrode 14.Produce in the liquid crystal layer 30 of tilting electric field on the marginal portion of opening 14a EG (the opening 14a inner peripheral part that comprises its border) of representing by equipotential line EQ sloping portion.

Torsional interaction has on the liquid crystal molecule 30a of negative dielectric anisotropic, so that the axle orientation of guiding liquid crystal molecule 30a is parallel to equipotential line EQ (perpendicular to line of electric force).Therefore, shown in the arrow among Fig. 2 A, liquid crystal molecule 30a clockwise direction on the right hand edge part EG among Fig. 2 A tilts (rotation) and liquid crystal molecule 30a on the left hand edge part EG counterclockwise tilt (rotation).Therefore, to be parallel to equipotential line EQ partially oriented accordingly for the liquid crystal molecule 30a on the EG of marginal portion.

With reference to figure 3A-3D, now the change in orientation of liquid crystal molecule 30a will be described in more detail.

When producing electric field in liquid crystal layer 30, torsional interaction has on the liquid crystal molecule 30a of negative dielectric anisotropic, so that guide its orientation to be parallel to equipotential line EQ.Graphic as Fig. 3 A institute, when having produced the electric field of representing by equipotential line EQ perpendicular to liquid crystal molecule 30a axle orientation, the moment of torsion that perhaps promotes liquid crystal molecule 30a clockwise direction to tilt occurs, the moment of torsion that perhaps promotes liquid crystal molecule 30a counterclockwise to tilt occurs, and their appearance has equal probabilities.Therefore, at this liquid crystal layer 30 between relative mutually parallel plate electrode is had some liquid crystal molecule 30a that suffer clockwise moment of torsion and suffer the liquid crystal molecule 30a of counterclockwise moment of torsion with some other.Therefore, according to the voltage that is applied on the liquid crystal layer 30, may carry out not steadily not smoothly to the transition of expection orientation.

When the marginal portion EG at the opening 14a of liquid crystal indicator 100 of the present invention produces an electric field (tilting electric field), as shown in Fig. 2 A, this electric field is represented by the part equipotential line EQ that tilts about liquid crystal molecule 30a axle orientation, shown in Fig. 3 B, liquid crystal molecule 30a is needing rotation still less so that be parallel to any direction of equipotential line EQ tilt (being counterclockwise in the graphic example) for liquid crystal molecule 30a.Shown in Fig. 3 C, liquid crystal molecule 30a in the zone that has produced the electric field of being represented by the equipotential line EQ perpendicular to liquid crystal molecule 30a axle orientation is tilting with the liquid crystal molecule 30a equidirectional that is positioned on the equipotential line EQ sloping portion, and its orientation is consistent continuous with the orientation of liquid crystal molecule 30a on being positioned at equipotential line EQ sloping portion thus.Graphic as Fig. 3 D institute, when making that equipotential line EQ forms the electric field of continuous concave/convex shape pattern, the liquid crystal molecule 30a that is positioned on the mild part of equipotential line EQ is orientated, so that with consistent by the direction of orientation that is positioned at the liquid crystal molecule 30a definition on the equipotential line EQ adjacent inclined part.It is " being positioned in the electric field of being represented by equipotential line EQ " that phrase used herein " is positioned on the equipotential line EQ " meaning.

The change in orientation of liquid crystal molecule 30a from being positioned at the liquid crystal molecule 30a on the equipotential line EQ sloping portion, is proceeded as mentioned above, reaches the stable state of schematic illustration among Fig. 2 B.Be positioned at the liquid crystal molecule 30a around the opening 14a core, be subjected to being positioned at the influence of each auto-orientation of the liquid crystal molecule 30a on the opposite edges part EG of opening 14a basic identically, the orientation that therefore keeps them is perpendicular to equipotential line EQ.Away from the liquid crystal molecule 30a at opening 14a center be subjected to keeping to the side other liquid crystal molecule 30a orientation on the part EG influence and tilt, therefore form tilted alignment about opening 14a center SA symmetry.(perpendicular to the direction on substrate 11 and 21 surfaces) viewed orientation on perpendicular to the direction of the display plane of liquid crystal indicator 100 is that liquid crystal molecule 30a has the state about the radial axle orientation (not shown) at opening 14a center.In this manual, this orientation will be called " radial skew orientation ".And the liquid crystal layer region of getting about the radial skew of single shaft orientation is called as " liquid crystal territory ".

The liquid crystal territory that liquid crystal molecule 30a gets the radial skew orientation also is formed on the zone, and this zone is corresponding to the solid portion 14b ' of unit that is surrounded basically by opening 14a.Be subjected to the influence of the liquid crystal molecule 30a orientation on each marginal portion EG of opening 14a corresponding to the liquid crystal molecule 30a in the zone of the solid portion 14b ' of unit, so that get the radial skew orientation, its center SA (corresponding to the cell center that forms by opening 14a) symmetry about the solid portion 14b ' of unit.

Radial skew in the liquid crystal territory of the middle formation of the solid portion 14b ' of unit orientation is consistent continuously each other with the radial skew orientation that forms in opening 14a, and all with opening 14a marginal portion EG on liquid crystal molecule 30a be orientated consistent.Liquid crystal molecule 30a in the liquid crystal territory that forms in opening 14a is oriented to taper shape, it is expansion (towards substrate 100b) upwards, liquid crystal molecule 30a in the liquid crystal territory of the middle formation of the solid portion 14b ' of unit is oriented to taper shape, and it is expansion (towards substrate 100a) downwards.As mentioned above, the radial skew orientation in the liquid crystal territory that forms in opening 14a is consistent continuously each other with the radial skew orientation in the liquid crystal territory of the middle formation of the solid portion 14b ' of unit.Therefore, form, prevent thus owing to the display quality decline that the swing offset line causes occurs along the displacement without spin of the border between them (disclination) line (orientation defective).

In order to improve the view angle dependency in all position angles, it is the display quality of liquid crystal indicator, rotates symmetry, more preferably rotational symmetry on the probabilistic optimum seeking ground that exists of liquid crystal molecule 30a in each pixel region of various azimuth direction orientations.In other words, the liquid crystal territory that forms on the whole pixel region preferably has the rotation symmetry, more preferably has rotational symmetry.Yet, notice that the rotation symmetry is not must be on whole pixel region, but the territory set of group liquid crystal more than each pixel region forms in the liquid crystal layer may be just enough, these groups are arranged as and make every group to have rotation symmetry (or rotational symmetry) (every group of liquid crystal territory wherein arranged with chequer in for example many group liquid crystal territory).Therefore, the arrangement of the opening 14a that forms in pixel region may not need have the rotation symmetry on whole pixel region, but arrange can be represented as the set of many group openings may be just enough, these opening groups are arranged in and make every group to have rotation symmetry (or rotational symmetry) (for example many group openings are wherein arranged every group of opening with chequer).Certainly, this is applied to the arrangement of the solid portion 14b ' of unit that surrounded basically by opening 14a similarly.And, because the shape in each liquid crystal territory preferably has the rotation symmetry, more preferably have rotational symmetry, so the shape of each opening 14a and each solid portion 14b ' of unit is preferably rotated symmetry, more preferably rotational symmetry.

Attention may not apply enough voltage on the liquid crystal layer 30 around the opening 14a core, the liquid crystal layer 30 around the opening 14a core does not work to demonstration thus.In other words, even the multilated of the radial skew of the liquid crystal layer 30 around opening 14a core orientation reaches to a certain degree (for example, even central shaft departs from opening 14a center), display quality may not reduce.Therefore, arrangement makes it have the rotation symmetry with the liquid crystal territory of the corresponding formation of the solid portion 14b ' of unit at least, and it is enough more preferably to have rotational symmetry.

With reference to figure 2A and Fig. 2 B, the pixel electrode 14 of liquid crystal indicator 100 of the present invention comprises a plurality of opening 14a as mentioned above, and 30 li generations of the liquid crystal layer in pixel region electric field, and this electric field is represented by the equipotential line EQ with sloping portion.The liquid crystal molecule 30a that has negative dielectric anisotropic in the liquid crystal layer 30, they are perpendicular alignmnet when not having impressed voltage, along with the change in orientation that is positioned at as the liquid crystal molecule 30a on the equipotential line EQ sloping portion of initiating signal (trigger), and change its direction of orientation.Therefore, the liquid crystal territory with stable radial skew orientation is formed among opening 14a and the solid portion 14b.The variation of voltage produces demonstration on the liquid crystal layer according to being applied to by liquid crystal molecule direction in the liquid crystal territory.

With describe present embodiment liquid crystal indicator 100 pixel electrode 14 opening 14a shape (as viewed on the substrate normal direction) and arrange.

Because the orientation (optical anisotropy) of liquid crystal molecule is arranged, and the display characteristic of liquid crystal indicator shows the position angle dependence.In order to reduce the position angle dependence of display characteristic, preferably on all position angles, make liquid crystal molecule be orientated with substantially the same probability.More preferably, with substantially the same probability the liquid crystal molecule in each pixel region is orientated.Therefore, opening 14a preferably has such shape, is exactly that the liquid crystal territory is formed in each pixel region, with substantially the same probability the liquid crystal molecule 30a in the pixel region is orientated thus.More particularly, the shape of opening 14a is preferably about passing the axis of symmetry rotation symmetry (more preferably double at least turning axle symmetry) of each open centre (on normal direction).Equally preferably arrange a plurality of opening 14a, make its rotation symmetry.And preferably the shape of the solid portion 14b ' of unit that is surrounded basically by these openings is also rotated symmetry.Equally preferably the unit's of arrangement solid portion 14b ' makes its rotation symmetry.

Yet, may not need aligned openings 14a or the solid portion 14b ' of unit so that on whole pixel region, have the rotation symmetry.When for example (have quadruple rotation axisymmetric) grid is as least unit, can be on all position angles on the whole pixel region to liquid crystal molecular orientation with substantially the same probability, as Figure 1A graphic, become pixel region by this criss-cross.

Will with reference to figure 4A-4C describe as Figure 1A institute graphic, when the liquid crystal molecule 30a that arranges rotational symmetric general star-shaped openings 14a and general circular unit solid portion 14b ' time in chequer is orientated.

Each figure illustrates map to separate as liquid crystal molecule 30a orientation observed on the substrate normal direction among Fig. 4 A-4C.In the figure of diagram as liquid crystal molecule 30a orientation observed on the substrate normal direction, for example Fig. 4 B and 4C, be depicted as the black patches end of oval-shaped liquid crystal molecule 30a, expression liquid crystal molecule 30a be tilted in case this end than the more approaching substrate which is provided with the pixel electrode 14 that contains opening 14a of other end.This is applied in all subsequent figure similarly.Individual unit lattice in the graphic pixel region among Figure 1A (it is formed by four opening 14a) hereinafter will be described.Each cornerwise cross-sectional view along Fig. 4 A-4C corresponds respectively to Figure 1B, Fig. 2 A and Fig. 2 B, in the following description also with reference to Figure 1B, Fig. 2 A and Fig. 2 B.

When pixel electrode 14 and counter electrode 22 are positioned at same potential, just be in no-voltage and be applied to state on the liquid crystal layer 30, shown in Fig. 4 A, by the liquid crystal molecule 30a perpendicular alignmnet of vertical alignment layer (not shown) adjustment direction of orientation, vertical alignment layer is arranged on the side of TFT substrate 100a and the close liquid crystal layer 30 that sets off by contrast end 100b.

When electric field is applied on the liquid crystal layer 30 so that when producing the electric field of being represented by equipotential line EQ shown in Fig. 2 A, torsional interaction has on the liquid crystal molecule 30a of negative dielectric anisotropic, so that the axle orientation of guiding liquid crystal molecule 30a is parallel to equipotential line EQ.As above with reference to as described in figure 3A and the 3B, for the liquid crystal molecule 30a under the electric field of representing by equipotential line EQ perpendicular to its molecular axis, be not inclination (rotation) direction (Fig. 3 A) that defines liquid crystal molecule 30a uniquely, change in orientation (tilting or rotation) is not easy to take place thus.On the contrary, for being placed on about the liquid crystal molecule 30a under the equipotential line EQ of liquid crystal molecule 30a molecular axis inclination, define (rotation) direction uniquely, change in orientation takes place easily thus.Therefore, as the diagram of Fig. 4 B institute, liquid crystal molecule 30a begins from opening 14a marginal portion to tilt, and tilts about equipotential line EQ at the molecular axis of this marginal portion liquid crystal molecule 30a.Then, with reference to as described in the figure 3C, liquid crystal molecule 30a on every side tilts as above, so that consistent with the liquid crystal molecule 30a orientation that tilted on the opening 14a marginal portion.Then, graphic as institute among Fig. 4 C, the axle of liquid crystal molecule 30a is orientated become stable (radial skew orientation).

As mentioned above, when the shape of opening 14a had the rotation symmetry, the liquid crystal molecule 30a in the pixel region tilted in succession, begins towards opening 14a center from opening 14a marginal portion according to voltage application.Therefore, obtain an orientation, keep perpendicular alignmnet at the pericentral liquid crystal molecule 30a of this orientation upper shed 14a about substrate plane, here each orientation adjusting power from liquid crystal molecule 30a on the marginal portion is balance, and liquid crystal molecule 30a on every side tilts about the pericentral liquid crystal molecule 30a of opening 14a in radial pattern, and along with increasing gradually away from the centroclinal degree of opening 14a.

Also tilt with the liquid crystal molecule 30a in the corresponding zone of the general circular solid portion 14b ' of unit, so that the liquid crystal molecule 30a orientation that tilts with the tilting electric field that has been produced on each opening 14a marginal portion is consistent, the solid portion 14b ' of unit is surrounded by four general star-shaped openings 14a that are arranged in the chequer.Therefore, obtain an orientation, the pericentral liquid crystal molecule 30a of the solid portion 14b ' of unit keeps perpendicular alignmnet about substrate plane on this orientation, here each orientation adjusting power from liquid crystal molecule 30a on the marginal portion is balance, and liquid crystal molecule 30a on every side tilts about the pericentral liquid crystal molecule 30a of the solid portion 14b ' of unit in radial pattern, and along with increasing gradually away from the unit centroclinal degree of solid portion 14b '.

As mentioned above, when the liquid crystal molecule 30a in each gets the liquid crystal territory of radial skew orientation when arranging on the whole pixel region in a chequer, the probability that exists of the liquid crystal molecule 30a of each orientation has the rotation symmetry, may realize high-quality demonstration thus, for any visual angle, not have heterogeneity.In order to reduce the view angle dependency in the liquid crystal territory with radial skew orientation, the liquid crystal territory preferably has highly rotation symmetry (preferably have double turning axle at least, more preferably have the quadruple turning axle at least).And, in order to reduce the view angle dependency on the whole pixel region, the a plurality of liquid crystal territory that is arranged in the pixel region preferably is arranged in (for example chequer) in the pattern, it is the combination of a plurality of unit cell pattern (for example cell pattern), each pattern has highly rotation symmetry (preferably have double turning axle at least, more preferably have the quadruple turning axle at least).

For the radial skew orientation of liquid crystal molecule 30a, graphic as Fig. 5 B or Fig. 5 C institute, have the radial skew orientation of counterclockwise or clockwise spiral pattern respectively, more stable than the graphic simple radial skew orientation of institute among Fig. 5 A.Screw orientation is different from common torsional direction (changing in the direction of orientation of this direction liquid crystal molecule 30a thickness spirality along liquid crystal layer 30).In screw orientation, for tiny area, the direction of orientation of liquid crystal molecule 30a does not change basically along the thickness of liquid crystal layer 30.In other words, the orientation (in being parallel to the plane of layer plane) in the xsect on liquid crystal layer 30 any thickness is graphic as Fig. 5 B or Fig. 5 C institute, does not have torsional deflection basically along liquid crystal layer 30 thickness.Yet may there be torsional deflection to a certain degree in the liquid crystal territory for as a whole.

When use obtains a kind of material by the chirality agent is added in the nematic liquid crystalline material with negative dielectric anisotropic, exist under the situation of impressed voltage, shown in Fig. 5 B or 5C, liquid crystal molecule 30a gets the radial skew orientation about the counterclockwise or clockwise spiral pattern of opening 14a and the solid portion 14b ' of unit respectively.Spiral pattern is to be determined by the type of the chirality agent of using counterclockwise or clockwise.Therefore, when having impressed voltage, by the liquid crystal layer 30 in the control opening 14a is the radial skew orientation of spiral pattern, the liquid crystal molecule 30a of radial skew can be constant about the spiral pattern direction perpendicular to other liquid crystal molecule 30a of substrate plane in all liquid crystal territories, may realize thus evenly showing and does not have a demonstration heterogeneity.Because perpendicular to the spiral pattern direction around the liquid crystal molecule 30a of substrate plane is clear and definite, so the response speed that the voltage on the liquid crystal layer 30 applies also is improved.

And when increasing the chirality agent, the orientation of liquid crystal molecule 30a is as changing in spiral pattern along liquid crystal layer 30 thickness on normal twist alignment.The orientation of liquid crystal molecule 30a along liquid crystal layer 30 thickness in spiral pattern on the indeclinable orientation, perpendicular to or the liquid crystal molecule 30a that is parallel to the polarization axle orientation of polarization plates do not differ to incident light, the incident light that passes this orientation area thus can not promote transmission.On the contrary, on the orientation that the orientation of liquid crystal molecule 30a changes in spiral pattern along liquid crystal layer 30 thickness, perpendicular to or the liquid crystal molecule 30a that is parallel to the polarization axle orientation of polarization plates also differ to incident light, and optical rotatory power also can utilize, and the incident light that passes this orientation area thus also promotes transmission.Therefore, may obtain to produce the liquid crystal indicator of a bright demonstration.

Figure 1A illustrates each opening 14a wherein and has the example that general star and each solid portion 14b ' of unit have general circle, and wherein such opening 14a and such solid portion 14b ' of unit are arranged in the chequer.Yet shape and their arrangement of the shape of opening 14a, the solid portion 14b ' of unit are not limited to above-mentioned example.

Fig. 6 A and Fig. 6 B are the planimetric maps of difference diagram pixel electrode 14A and 14B, and they have difform opening 14a and the solid portion 14b ' of unit respectively.

The opening 14a of graphic pixel electrode 14A and 14B and the solid portion 14b ' of unit are respectively the distortion slightly of graphic pixel electrode among Figure 1A in Fig. 6 A and Fig. 6 B.The opening 14a of pixel electrode 14A and 14B and the solid portion 14b ' of unit have dual turning axle (not being the quadruple turning axle), and by regularly arranged so that form the rectangular elements lattice.In pixel electrode 14A and 14B, opening 14a is distortion star, and the solid portion 14b ' of unit is general oval (distortion is circular).Equally, use this pixel electrode 14A and 14B, may obtain having the liquid crystal indicator of high display quality and desirable viewing angle characteristic.

And, as selection, can use graphic pixel electrode 14C and 14D in Fig. 7 A and Fig. 7 B respectively.

In pixel electrode 14C and 14D, general cruciform opening 14a is arranged in the chequer, makes each solid portion 14b ' of unit be general square.Certainly, the pattern of pixel electrode 14C and 14D can be out of shape, and making has the rectangular elements lattice.As mentioned above, as selection,, may obtain having the liquid crystal indicator of high display quality and desirable viewing angle characteristic by regularly arranged general rectangle (comprising square and rectangle) the solid portion 14b ' of unit.

Yet the shape of opening 14a and/or the solid portion 14b ' of unit is preferably circular or oval, rather than rectangle, and the radial skew orientation is more stable thus.Think and use circle or elliptical openings and/or unit solid portion, the radial skew orientation is more stable, because the edge of opening 14a more continuous (smoothly), the direction of orientation of liquid crystal molecule 30a more continuous (smoothly) changes thus.

Consider above-mentioned liquid crystal molecule 30a direction of orientation continuity, graphic pixel electrode 14E and 14F also want in Fig. 8 A and Fig. 8 B respectively.The modification that graphic pixel electrode 14E is a graphic pixel electrode 14 among Figure 1A among Fig. 8 A, each opening 14a is made up of four circular arcs simply in Figure 1A.The modification that graphic pixel electrode 14F is graphic pixel electrode 14D among Fig. 7 B among Fig. 8 B, in Fig. 7 B, each side of opening 14a on the solid portion 14b ' of unit is a circular arc.In pixel electrode 14E and 14F, opening 14a and the solid portion 14b ' of unit have the quadruple turning axle, and are arranged in (having the quadruple turning axle) chequer.As selection, as shown in Fig. 6 A and Fig. 6 B, the shape of the solid portion 14b ' of unit of opening 14a can be deformed into the shape with double turning axle, (the having double turning axle) pane of can arranging such solid portion 14b ' of unit so that form.

In above-mentioned example, opening 14a is general star or general cruciform, and the solid portion 14b ' of unit is general circle, general oval, general square (rectangle) and the general rectangle with fillet.As selection, the negative-positive relationship between opening 14a and the solid portion 14b ' of unit can anti-phase (hereinafter, the negative positive relationship conversion between opening 14a and the solid portion 14b ' of unit will be called " anti-phase " simply).For example, Fig. 9 illustrates the pixel electrode 14G with a certain pattern, and this pattern obtains by the opening 14a of graphic pixel electrode 14 among anti-phase Figure 1A and the negative-positive relationship between the solid portion 14b ' of unit.Pixel electrode 14G with reverse tone have basically with Figure 1A in graphic pixel electrode 14 identical functions.When opening 14a and the solid portion 14b ' of unit had general square, as respectively in Figure 10 A and Figure 10 B among graphic pixel electrode 14H and the 14I, reverse tone basically can be identical with master pattern.

Same be among Fig. 9 during graphic pattern when graphic pattern among Figure 1A is anti-phase, preferably forms the part part (be generally half or 1/4th) of opening 14a, so that the formation solid portion 14b ' of unit, it rotates symmetrical on the marginal portion of pixel electrode 14.By using such pattern, on the marginal portion of pixel region, can obtain the tilting electric field effect, in the core as pixel region, thus, may on whole pixel region, realize stable radial skew orientation.

Secondly, to discuss about graphic pixel electrode 14G among the pixel electrode 14 of Figure 1A and Fig. 9 and use in two anti-phase patterns which, pixel electrode 14G has a certain pattern, and this pattern obtains by the opening 14a of anti-phase pixel electrode 14 and the pattern of the solid portion 14b ' of unit.

For arbitrary pattern, the girth of each opening 14a is identical.Therefore, there is not difference in the function for producing tilting electric field between two patterns.Yet the unit solid portion 14b ' area between two patterns can be different than (about the total area of pixel electrode 14).In other words, producing an area (part that has conducting film) that acts on the solid portion 14b of electric field on the liquid crystal molecule of liquid crystal layer between them can be different.

The voltage that applies by the liquid crystal territory that is formed among the opening 14a is lower than the voltage that applies by another liquid crystal territory that is formed among the solid portion 14b.Therefore, in normal black mode showed, for example, the liquid crystal territory that is formed among the opening 14a seemed darker.Therefore, because opening 14a area ratio increases, display brightness reduces.Therefore, preferably solid portion 14b area ratio is high.

Be that solid portion 14b area depends on the spacing (size) of cell than higher in Figure 1A pattern or in Fig. 9 pattern.

Figure 11 A illustrates graphic pattern unit lattice among Figure 1A, and Figure 11 B illustrates graphic pattern unit lattice (opening 14a is as the center of each lattice) among Fig. 9.In Figure 11 B, ignored the part that is used for shown in Fig. 9 the adjacent solid portion 14b ' of unit is linked together (beginning component) in the four direction expansion from circular portion.Side's cell one side length (spacing) uses " s " to represent with " p " expression, the distance (side is apart from width) between opening 14a or solid portion 14b ' of unit and the cell side.

Generation has different spacing p and the side various samples apart from the pixel electrode 14 of s, so that the stability of test radial skew orientation etc.Therefore, find that side need be about 2.75 μ m or more apart from s, obtains radial skew orientation so that produce required tilting electric field for having the pixel electrode 14 of (hereinafter, being called " positive pattern ") of graphic pattern among Figure 11 A.Discovery is for having the pixel electrode 14 of (hereinafter, being called " negative pattern ") of graphic pattern among Figure 11 B, and side need be about 2.25 μ m or more apart from s, obtains radial skew orientation so that produce required tilting electric field.For each pattern, when along with side is fixed to it when changing spacing p value more than the lower limit apart from s, solid portion 14b area ratio obtains testing.The result is illustrated among following table 1 and Figure 11 C.

[table 1]

Spacing p (μ m) solid portion area is than (%)

(Figure 11 B) that positive (Figure 11 A) is negative

?20 ?25 ?30 ?35 ?40 ?45 ?50

?41.3 ?47.8 ?52.4 ?55.8 ?58.4 ?60.5 ?62.2

?52.9 ?47.2 ?43.3 ?40.4 ?38.2 ?36.4 ?35.0

As seeing from table 1 and Figure 11 C, when spacing p is about 25 μ m or more for a long time, positive pattern (Figure 11 A) has higher solid portion 14b area ratio, as spacing p during less than about 25 μ m, negative pattern (Figure 11 B) has higher solid portion 14b area ratio.Therefore, consider display brightness and orientation stability, the pattern that should use changes on about 25 μ m critical gap p.For example, when on the Width of width, providing three or still less during cell, graphic positive pattern is preferred among Figure 11 A, when providing four or more during the multiple-unit lattice, graphic negative pattern is preferred among Figure 11 B for 75 μ m pixel electrodes 14.For being different from graphic pattern herein, can between positive pattern and negative pattern, select similarly, so that obtain big solid portion 14b area ratio.

Can following determining unit lattice quantity.Calculate each cell size, arrange one or more (integer) cell along the width (level or vertical) of pixel electrode 14 thus, the cell size of each calculating is calculated solid portion area ratio.Then, select the solid portion area than maximized cell size.Note,, reduce, thus, be not easy to obtain stable radial skew orientation from the orientation adjusting power of tilting electric field when the diameter of solid portion 14b ' of unit (for positive pattern) or opening 14a (for negative pattern) during less than 15 μ m.The thickness that the diameter limit value is used for liquid crystal layer 30 is about the situation of 3 μ m.When liquid crystal layer 30 thickness during, even, can obtain stable radial skew orientation when the diameter of solid portion 14b ' of unit and opening 14a during less than lower limit less than about 3 μ m.When liquid crystal layer 30 thickness during greater than about 3 μ m, the diameter limit value that is used to obtain the solid portion 14b ' of unit of stable radial skew orientation and opening 14a is greater than above-mentioned lower limit.

Note, described in hereinafter, give prominence to, can increase the stability of radial skew orientation by in opening 14a, forming.The above-mentioned all conditions that provides is used for there is not to form outstanding situation.

As mentioned above, by a kind of electrode structure is provided, may realize a kind of display with wide visual angle, this electrode structure applies orientation adjusting power and forms a liquid crystal territory, and the radial skew orientation is got in this liquid crystal territory in pixel region.

Yet the inventor only has been found that can not fully improve display quality by above-mentioned electrode structure is provided, and this depends on the opening 14a of pixel electrode 14 and is arranged on position relation between bus (the one group of interconnection line) edge on the TFT substrate 100a.In liquid crystal indicator 100 of the present invention, the opening 14a of pixel electrode 14 and bus edge are in position as described below relation, realize high-quality demonstration thus.

With reference to Figure 12, the opening 14a and the relation of the position between bus 18 edges of the pixel electrode 14 of liquid crystal indicator 100 of the present invention will be described now.Figure 12 is the planimetric map of liquid crystal indicator 100 pixel regions of schematically diagram present embodiment.Attention is omitted the TFT that is used for each pixel region that is arranged on the TFT substrate 100a in subsequent figure.

Graphic as Figure 12 institute, the TFT substrate 100a of liquid crystal indicator 100 is near comprising the pixel electrode 14 that is used for each pixel region on the side of liquid crystal layer 30, being electrically connected to the TFT (not shown) and the bus 18 of pixel electrode 14 as on-off element, bus 18 comprises grid bus (sweep trace) 15 and source bus line (signal wire) 16, and they are electrically connected to TFT.In the present embodiment, bus 18 also comprises the storage capacitor line 17 that is used to form holding capacitor.

In the present embodiment, graphic as institute among Figure 12, at least one opening 14a that arranges along bus 18 is stacked on the bus 18 in each pixel region.More particularly, in the opening 14a that arranges along bus 18, arrange and be arranged in two opening 14a between the adjacent cells solid portion 14b ' along grid bus 15 to be stacked in (grid bus 15) on the bus 18.Therefore, as observed, provide grid bus 15 so that the opening 14a of covering between adjacent cells solid portion 14b ' from TFT substrate 100a side.As observed, insert the edge of unit solid portion 14b ' overlies gate bus 15 of opening 14a therebetween from setting off by contrast end 100b side.Here, grid bus 15 is formed with component, and each part is all extended towards the opening 14a between the adjacent cells solid portion 14b ', and the opening 14a between the adjacent cells solid portion 14b ' is stacked on the grid bus 15 thus.

In liquid crystal indicator 100, as mentioned above, at least one opening 14a that arranges along bus 18 is stacked on the bus 18, realizes high-quality demonstration thus.Will be hereinafter with reference to Figure 13, Figure 14 A, 14B, 16A and 16B, compare with the situation that the opening 14a that arranges along bus 18 is not stacked on the bus 18, this reason is described.

Figure 13 is the planimetric map of diagram liquid crystal indicator 700 schematically, and wherein the opening 14a that arranges along bus 18 is not stacked on the bus 18.And, Figure 14 A and 14B schematically illustrate the orientation of the liquid crystal molecule 30a around the opening 14a, this opening 14a arranges that along the grid bus 15 of liquid crystal indicator 700 wherein Figure 14 A is a planimetric map, and Figure 14 B is the cross-sectional view along Figure 14 A line 14B-14B '.Figure 16 A and 16B schematically illustrate the orientation of the liquid crystal molecule 30a around the opening 14a, this opening 14a arranges along the grid bus 15 of present embodiment liquid crystal indicator 100, wherein Figure 16 A is a planimetric map, and Figure 16 B is the cross-sectional view along Figure 16 A line 16B-16B '.

When driving liquid crystal indicator, the prearranged signals (voltage) that is used to drive liquid crystal indicator offers bus 18, and bus 18 is arranged on the TFT substrate 100a, thus, produces electric field between bus 18 and counter electrode 22.Therefore, near bus 18 edges, produce tilting electric field.Yet, do not match with orientation adjusting power from the tilting electric field that results from opening 14a marginal portion from the orientation of the tilting electric field power of regulating.Therefore, if a liquid crystal territory is subjected to the adjusting power effect near the tilting electric field bus 18 edges, this liquid crystal territory is formed on along among the opening 14a of bus 18 layouts, and then the orientation in liquid crystal territory is interfered, and causes the radial skew orientation of being out of shape thus.

For example, graphic as Figure 13 institute, in liquid crystal indicator 700, wherein the opening 14a that arranges along bus 18 is not stacked on the bus 18, and when impressed voltage, the liquid crystal molecule 30a orientation around the opening 14a is as follows, and this opening 14a arranges along grid bus 15.Graphic as Figure 14 B institute, when impressed voltage, liquid crystal molecule 30a on the opening 14a marginal portion is counterclockwise tilted by a tilting electric field, this tilting electric field is created on the opening 14a marginal portion, yet near the liquid crystal molecule 30a grid bus 15 edges is tilted by a tilting electric field clockwise direction, and this tilting electric field is created near the grid bus 15.Therefore, graphic as institute among Figure 14 A, the liquid crystal layer 30 among the opening 14a forms the liquid crystal territory (being that flattening is circular) with distortion radial skew orientation in graphic example.

Owing to arrange that the adjacent lcd territory keeps the orientation continuity between them in advance, therefore the orientation in the orientation disturbing effect adjacent lcd territory in the liquid crystal territory among the opening 14a that arranges along bus 18, just, be formed on the orientation in the liquid crystal territory among the adjacent cells solid portion 14b '.Therefore, in adjacent cells solid portion 14b ', liquid crystal territory orientation is interfered equally.

One, because it disturbs in the liquid crystal territory of getting distortion radial skew orientation, this is orientated unstable and its easy breaking-up, and behind the impressed voltage, the orientation in such liquid crystal territory needs for a long time before reaching stable state thus.Therefore, aforesaid orientation is disturbed and is caused response speed to reduce (response characteristic degeneration).

And the liquid crystal layer 30 in each pixel region reaches the stable state of the radial skew orientation with this distortion, and wherein orientation is interfered, and the orientation of being disturbed changes to another from a pixel region.Therefore, persistence of vision may occur, and wherein after the image switching signal input, the image of Xian Shiing is remaining before.This is that transmission changes between the different pixels district equally because if being oriented between the different pixels district of liquid crystal layer 30 changes.Especially, there is significant difference in liquid crystal layer 30 orientations between two pixel regions, a pixel region shows that from white being transformed into intermediate grey scales shows, another pixel region is transformed into intermediate grey scales from black display and shows that the transmission difference between this pixel region may be considered to persistence of vision.This is because following reason.In white showed, the tilting electric field that produces on the opening 14a marginal portion applied strong relatively orientation and regulates power, and thus, the orientation of liquid crystal layer 30 is stable.Therefore, even be transformed into after intermediate grey scales shows, the orientation of liquid crystal layer 30 is stable.On the other hand, when being transformed into intermediate grey scales from black display and showing, the orientation of liquid crystal layer 30 may be damaged because from the orientation that results from the tilting electric field on the opening 14a marginal portion regulate power relatively a little less than.

On the contrary, graphic as Figure 12 institute, liquid crystal indicator 100 of the present invention is designed to like this, be exactly among the opening 14a that arranges along bus 18 at least one, particularly along grid bus 15 layouts and the opening 14a between two adjacent cells solid portion 14b ', be stacked in (grid bus 15) on the bus 18, thus near being stacked in of the unit solid portion 14b ' covering of bus 18 edges of the opening 14a on the bus 18 by pixel electrode 14.

Therefore, near the opening 14a that is stacked on the bus 18, the liquid crystal molecule 30a of liquid crystal layer 30 obtains electric shield by the solid portion 14b ' of unit of pixel electrode 14, exempts near the influence of the tilting electric field that produces bus 18 edges.Therefore, the liquid crystal molecule 30a of liquid crystal layer 30 does not suffer to regulate the power effect near the orientation of the tilting electric field that produces bus 18 edges, and its orientation is only regulated by the tilting electric field that results from opening 14a marginal portion.

Therefore, in liquid crystal indicator 100 of the present invention, in the liquid crystal territory in being formed at the opening 14a that is stacked on the bus 18, or in the liquid crystal territory in being formed at the solid portion 14b ' of unit of adjacent openings 14a, orientation is interference-free, suppress response speed minimizing (response characteristic degeneration) and persistence of vision thus and occurred, therefore realized high-quality demonstration.

Note,, and cause contrast ratio to reduce, if but bus 18 photoresist manufacturing can suppress the contrast ratio reduction although near the tilting electric field that produces bus 18 edges not only causes aforesaid response speed to reduce and persistence of vision.Now with more detailed description this.

As mentioned above, near bus 18 edges, produce tilting electric field,, all produce tilting electric field no matter on the liquid crystal layer 30 between pixel electrode 14 and the counter electrode 22, have/do not have impressed voltage.Therefore, producing in the liquid crystal indicator that shows with common black mode, if when not having impressed voltage by near the liquid crystal molecule 30a orientation adjusting power inclination bus 18 edges of tilting electric field, light leak may occur, and reduces contrast ratio thus.Especially, keep TFT to turn-off because 15 mosts of the time of grid bus apply high relatively voltage (shutoff voltage), near grid bus 15 edges, this light leak degree is tangible.

In liquid crystal indicator 100 of the present invention, near being stacked in of the unit solid portion 14b ' covering of bus 18 edges of the opening 14a on the bus 18 by pixel electrode 14, thus, the liquid crystal molecule 30a of liquid crystal layer 30 obtains electric shield, exempts near the influence of the tilting electric field that produces bus 18 edges.Therefore, the liquid crystal molecule 30a of liquid crystal layer 30 does not suffer to tilt from the orientation adjusting power of tilting electric field.Although the liquid crystal molecule 30a of the liquid crystal layer 30 among the opening 14a on being stacked in bus 18 can be tilted by the electric field that produces between bus 18 and the counter electrode 22, if but bus 18 photoresist manufacturing is stacked in the opening resistance light on the bus 18.

Therefore, if bus 18 photoresist manufacturing has suppressed to realize more high-quality demonstration thus owing to the contrast ratio reduction that light leak causes occurring.

And, if bus 18 photoresist manufacturing just as will be described hereinafter, may suppress the heterogeneity (localized variation of contrast ratio just) in the display plane, improve display quality thus.

Near because the tilting electric field that produces bus 18 edges, residual charge may appear among the opening 14a, expose insulating material by opening 14a, if, will cause light leak because the influence of residual charge is tilted along the liquid crystal molecule 30a among the opening 14a of bus 18 layouts.Though the degree of residual charge depends on the surface condition of insulating material and changes, maybe when injecting liquid crystal material, the surface condition of insulating material changes and occurs during not excessive print register film.Therefore, in liquid crystal indicator, there is variation in the residual charge in the display plane.If residual charge changes in display plane, the light leak degree also changes in display plane so, causes the contrast ratio localized variation thus, therefore produces heterogeneity.Especially, as mentioned above, because high relatively voltage is applied to grid bus 15, so grid bus 15 obviously helps to occur heterogeneity.

In liquid crystal indicator 100 of the present invention, when bus 18 usefulness photoresists were made, the opening 14a that is stacked on the bus 18 was blocked by bus 18, had suppressed aforesaid heterogeneity thus and had occurred, and had therefore improved display quality.

And, in near grid bus 15 edges of the graphic liquid crystal indicator 700 of Figure 13, graphic as Figure 15 A (along the cross-sectional view of Figure 13 line 15A-15A ') institute, there are some zones, in these zones, do not form the conducting film (solid portion 14b) of pixel electrode 14, graphic as Figure 15 B (along the cross-sectional view of Figure 13 line 15B-15B ') institute, there is some other zone, in these zones, form the conducting film of pixel electrode 14.Therefore, do not form near grid bus 15 edges in the zone of conducting film (solid portion 14b), graphic as Figure 15 A institute, because grid bus 15, foreign ion is attracted on the surface of TFT substrate 100a by electric field, thus because the orientation interference appears in the foreign ion electric charge (hereinafter being called " stored charge ") of absorption.Therefore, even bus 18 photoresist manufacturing, in each opening portion near grid bus 15 (the area L L that with dashed lines is demarcated among Figure 13), because stored charge, orientation is disturbed and is occurred, and causes light leak thus.

On the contrary, in liquid crystal indicator 100 of the present invention, in the zone that is subjected to the strong influence of electric field owing to grid bus 15, just, there are many zones near the zone the grid bus 15, in these zones, form the conducting film (solid portion 14b) of pixel electrode 14, as the graphic zone of Figure 15 B, suppressed thus therefore to have suppressed light leak because the orientation that stored charge causes is disturbed.

And, cause the impurity of stored charge anisotropically to be distributed in the display plane, but in display plane, be localized to the striated pattern usually.This is because when injecting liquid crystal material by a plurality of inlets of arranging according to predetermined space, compare with other zone, and liquid crystal material flows into the zone between the inlet slowlyer, and impurity is confined in this zone thus.

Therefore, the degree that forms or lose stored charge changes between the striated zone (having more polymictic zone) of impurity limitation and another zone (having the still less zone of impurity), light leak degree variation between striated zone and another are regional thus.Therefore, in the graphic liquid crystal indicator 700 of Figure 13, the striated zone shows as " secret note ", and brightness here is higher than other zone, or IOU note, and brightness here is lower than other zone, causes showing heterogeneity thus.

On the contrary, as mentioned above, liquid crystal indicator 100 of the present invention has suppressed itself because the appearance of the light leak that stored charge causes has suppressed to show heteropical appearance thus.

Note, though a kind of like this situation described above, this situation is exactly in each pixel region, and at least one is stacked on the bus 18 among the opening 14a that arranges along bus 18, it is along between grid bus 15 layouts and the solid portion 14b ' of the unit of being arranged in, but the present invention is not limited to this.By using an arrangement, this arrangement is exactly in each pixel region, along at least one is stacked on the bus 18 among the opening 14a between bus 18 layouts and the solid portion 14b ' of the unit of being arranged in, the orientation that has suppressed in the liquid crystal territory is disturbed, and has suppressed the reduction (response characteristic degeneration) of response speed and the appearance of persistence of vision thus.

For the orientation that suppresses to produce owing near the tilting electric field that produces bus 18 edges is disturbed, preferably increase opening 14a and be stacked in ratio on the bus 18, just increase bus 18 by the marginal portion of the solid portion 14b ' of the unit covering of pixel electrode 14.Yet under the situation that bus 18 usefulness photoresists are made, the increase of this ratio may reduce the aperture ratio.Therefore, consider desirable response characteristic and aperture ratio,, suitably determine to be stacked in the ratio of the opening 14a on the bus 18 according to application of liquid crystal indicator etc.

Certainly, the opening 14a between two adjacent solid portion 14b ' of unit not only, and also the opening 14a that arranges along bus 18 can be stacked on the bus 18.For example, in a plurality of opening 14a of pixel electrode 14, all opening 14a that arrange along grid bus 15 can be stacked on the bus 18, as in the graphic liquid crystal indicator 100A of Figure 17.

In the graphic liquid crystal indicator 100 of Figure 12, there is part opening 14a, it is not stacked on the bus 18 in (near the point of crossing between grid bus 15 and the source bus line 16) on the pixel region angle.On the contrary, in the graphic liquid crystal indicator 100A of Figure 17, even on the pixel region angle, grid bus 15 edges are by the solid portion 14b ' of unit covering, and all opening 14a that arrange along grid bus 15 are stacked on the bus 18.

In the graphic liquid crystal indicator 100A of Figure 17, a major part at bus 18 edges is provided bigger inhibition orientation interference effect thus by the solid portion 14b ' of the unit covering of pixel electrode 14.Yet notice that compare with the arrangement that the graphic part opening 14a that wherein is positioned on the pixel region angle of Figure 12 also is stacked on the bus 18, the crossing area between grid bus 15 and the source bus line 16 is bigger, stray capacitance may be very big thus.Therefore, though disturb in order to suppress orientation, the graphic arrangement of Figure 17 may be preferred, but in order to reduce stray capacitance, the graphic arrangement of Figure 12 may be preferred.Certainly, graphic as Figure 12 institute, as long as along at least one is stacked on the bus 18 among the opening 14a of bus 18 layouts, this opening 14a arranges and is arranged between the adjacent cells solid portion 14b ' along grid bus 15, just can fully suppress the orientation interference and can access sufficiently high display quality.

Represented that respectively grid bus 15 comprises the component that extends to opening 14a though note Figure 12 and 17, opening 14a is stacked in the situation on the grid bus 15 thus, but the present invention is not limited to this.As selection, as in the graphic liquid crystal indicator 100B of Figure 18, can increase the width of grid bus 15, make the opening 14a that arranges along grid bus 15 be stacked in (edge of grid bus 15 is by the solid portion 14b ' of the unit covering of pixel electrode 14 thus) on the grid bus 15.Yet notice, compare with 17 graphic arrangements that when increasing the width of grid bus 15, the overlapping area between grid bus 15 and the solid portion 14b ' of unit increases, and increases the gate-to-drain stray capacitance thus with Figure 12.And, compare with 17 graphic arrangements with Figure 12, when grid bus 15 usefulness photoresists were made, the aperture was than reducing.Therefore, in order to reduce stray capacitance and to improve the aperture ratio, Figure 12 and 17 graphic arrangements are preferred.

And, when driving liquid crystal indicator 100, compare with source bus line 16, big voltage generally is applied to grid bus 15, thus, compare with near the tilting electric field that produces source bus line 16 edges, near the tilting electric field that produces grid bus 15 edges is bigger to the liquid crystal molecule influence.

Therefore, as in Figure 12 and 17 graphic liquid crystal indicators 100 and 100A, by using a certain arrangement, wherein among the opening 14a that arranges along bus 18 at least one or all be stacked on the bus 18 (grid bus 15), this opening 14a arranges along grid bus 15, may suppress the reduction of response speed and the appearance of persistence of vision effectively, and not cause unnecessary aperture than reducing.

Certainly, as in Figure 19 and 20 graphic liquid crystal indicator 100C and 100D, may use a kind of arrangement, wherein among the opening 14a that arranges along source bus line 16 at least one or all be stacked on the bus 18, or a kind of arrangement, wherein the opening 14a along grid bus 15 and source bus line 16 layouts all is stacked on the bus 18.In Figure 19 and 20 graphic liquid crystal indicator 100C and 100D, source bus line 16 comprises the component that extends towards opening 14a, the opening 14a that arranges along grid bus 15 not only, and also the opening 14a that arranges along source bus line 16 is stacked on the bus 18.

In addition, as required, among the opening 14a that arranges along storage capacitor line 17 at least one or all can be stacked on the bus 18.

Note, the present invention be not limited to comprise Figure 12 the liquid crystal indicator of graphic pixel electrode 14 grades, but the present invention certainly uses with other suitable liquid crystal indicator, these liquid crystal indicators comprise the pixel electrode 14 of various other shapes.Can carry out various modifications to quantity or the arrangement of the solid portion 14b ' of unit of pixel electrode 14 equally.For example, the present invention can suitably use with a liquid crystal indicator, it is in each pixel electrode 14, the solid portion 14b ' of unit with relatively small amount, for example a kind of liquid crystal indicator, wherein the direction of extending along source bus line 16 in each pixel region is arranged three solid portion 14b ' of unit.

Aforesaid liquid crystal indicator 100 can use and the identical arrangement of perpendicular alignmnet type liquid crystal indicator known in the art, except pixel electrode 14 comprises opening 14a and bus 18 has the reservation shape, can produce by known production method.

Usually, a vertical alignment layer (not shown) is arranged on a side of each pixel electrode 14 and counter electrode 22 close liquid crystal layers 30, so that perpendicular alignmnet has the liquid crystal molecule of negative dielectric anisotropic.

Liquid crystal material can be the nematic liquid crystalline material with negative dielectric anisotropic.By dichroic dyestuff (dichroic dye) is added in the nematic liquid crystalline material with negative dielectric anisotropic, can obtain visitor-master (guest-host) mode LCD.Visitor-holotype liquid crystal indicator does not need polarization plates.

This situation is described above, be exactly that bus 18 forms reservation shape (graphic shape with component of Figure 12 or the like for example, or the graphic shape with big width of Figure 18), the edge of bus 18 is covered by the solid portion 14b of pixel electrode 14 (the solid portion 14b ' of unit) thus.Yet the present invention is not limited to this.As selection, by the solid portion 14b ' of unit (or opening 14a), and do not change the shape of bus 18 according to predetermined arranged pixel electrode 14, the edge of bus 18 can be covered by solid portion 14b.

For example,, can form pixel electrode 14, make the solid portion 14b ' of part unit (shape is corresponding with about half solid portion 14b ' of unit) arrange along grid bus 15 as in Figure 21 A and the graphic liquid crystal indicator 100E of 21B.In liquid crystal indicator 100E, the solid portion 14b ' of part unit arranges along grid bus 15, thus when impressed voltage between pixel electrode 14 and counter electrode 22, liquid crystal layer 30 forms part liquid crystal territory, and it gets the radial skew orientation in a part of solid portion 14b (the solid portion 14b ' of part unit) that arranges along grid bus 15.

In liquid crystal indicator 100E, as graphic at Figure 21 A and 21B, the edge of grid bus 15 covers by the solid portion 14b ' of part unit (shape is corresponding with about half solid portion 14b ' of unit) with the component that the solid portion 14b ' of these units is electrically connected, therefore, the edge of grid bus 15 is covered by solid portion 14b.Therefore, can obtain the effect identical with the graphic liquid crystal indicator of for example Figure 12 100.And, in liquid crystal indicator 100E, do not need to form grid bus 15 with component or the width that increases grid bus 15, even bus 18 photoresist manufacturing thus, unnecessary aperture does not occur than reducing.

Hereinafter the aperture of each liquid crystal indicator 100E of table 2 expression and 100F is than (" AR "), institute's diagram among liquid crystal indicator 100E such as Figure 21 A and the 21B, and wherein grid bus 15 comprises institute's diagram among the liquid crystal indicator 100F of component such as Figure 22 A and the 22B.Table 2 is also represented the ratio (" AR ratio ") of liquid crystal indicator 100E about the aperture ratio of liquid crystal indicator 100F.

[table 2]

	??13″		??15″		??20″		??22″
									??AR	The AR ratio	??AR	The AR ratio	??AR	The AR ratio	??AR	The AR ratio
	??LCD100F	??51.2％	??101.2％	??57.4％	??100.9％	??57.9％	??100.8％	??58.3％									??100.9％
??LCD100E									??51.8％	??58.0％	??58.3％	??58.8％

As shown in table 2, liquid crystal indicator 100E has aperture ratio, for 13 ", 15 "-, in 20 " and 22 "-liquid crystal boards any one, this aperture is than improving about 1% (0.8%-1.2%).Note, need not to show that table 2 indicating value is to be used for special requirement, even can think higher aperture than some specification that is used for liquid crystal indicator.

Though Figure 21 A and 21B illustrate a kind of situation, wherein grid bus 15 edges are covered by the solid portion 14b of pixel electrode 14, but preferably, the edge of at least one is covered by the solid portion 14b of pixel electrode 14 in grid bus 15 and the source bus line 16.As in the graphic liquid crystal indicator 100G of Figure 23, as selection, the solid portion 14b ' of unit can be arranged to like this, and grid bus 15 edges and source bus line 16 edges are all covered by the solid portion 14b of pixel electrode 14.In liquid crystal indicator 100G, as the diagram of Figure 23 institute, the solid portion 14b ' of part unit (shape is corresponding with about half solid portion 14b ' of unit) arranges that along source bus line 16 source bus line 16 edges are also covered by the solid portion 14b of pixel electrode 14 thus.Therefore, may further improve inhibition orientation effects of jamming.

As mentioned above, the arrangement of the solid portion 14b ' of unit (or opening 14a) by suitable setting pixel electrode 14 may suppress to be orientated and disturb and do not change the shape of bus 18.Figure 24 A and 24B and Figure 25 A and 25B illustrate replacement liquid crystal device 100H and the 100I according to the embodiment of the invention respectively.

In each liquid crystal indicator 100H and 100I, the shape of each solid portion 14b ' of unit of pixel electrode 14 is general star, its have eight limits (edge) and therein the heart have the quadruple turning axle.And opening 14a is general rhombus.

Graphic as Figure 24 A and 24B institute, in liquid crystal indicator 100H, grid bus 15 edges form serrate, and grid bus 15 edges are covered by the solid portion 14b of pixel electrode 14 thus.On the other hand, graphic as Figure 25 A and 25B institute, in liquid crystal indicator 100I, the general solid portion 14b ' of star unit of part (shape is corresponding with about half solid portion 14b ' of unit) provides along grid bus 15 with along source bus line 16, and grid bus 15 edges and source bus line 16 edges are covered by the solid portion 14b of pixel electrode 14 thus.Therefore, in liquid crystal indicator 100I, may prevent that the aperture is than unnecessary reduction.

Alternate embodiment

A pixel region structure of the liquid crystal indicator 200 of alternate embodiment according to the present invention will be described with reference to figure 26A and 26B.And, in subsequent figure, have with liquid crystal indicator 100 in each element of the substantially the same function of respective element will represent with identical Reference numeral, and below this element will be described no longer.Figure 26 A is a viewed planimetric map on the substrate normal direction, and Figure 26 B is the cross-sectional view along the line 26B-26B ' of Figure 26 A.Figure 26 B illustrates the state that the liquid crystal layer two ends do not have impressed voltage.

As Figure 26 A and the diagram of 26B institute, the graphic liquid crystal indicator of liquid crystal indicator 200 and Figure 1A and 1B institute 100 is different, and wherein TFT substrate 200a comprises among the opening 14a of pixel electrode 14 one outstanding 40.Perpendicular alignmnet film (not shown) is arranged on outstanding 40 the surface.

As the diagram of Figure 26 A institute, are general star-shaped cross-section along outstanding 40 the xsect on substrate 11 planes, just, shape is identical with opening 14a shape.Notice that adjacent outstanding 40 interconnect, so that surround each the solid portion 14b ' of unit in the general circular pattern fully.As the diagram of Figure 26 B institute, the edge is trapezoidal perpendicular to outstanding 40 xsects on the plane of substrate 11.More particularly, xsect has upper surface 40t and the side surface 40s that is parallel to substrate plane, and side surface 40s is about the substrate plane coning angle θ (＜90 °) that tilts.Owing to provide perpendicular alignmnet film (not shown) so that covering gives prominence to 40, so outstanding 40 side surface 40s has orientation adjusting power, its direction is identical with the direction of the tilting electric field of the liquid crystal molecule 30a of liquid crystal layer 30, is used for stabilization radial skew orientation thus.

To outstanding 40 function be described with reference to figure 27A-27D, 28A and 28B.

At first, will describe the orientation of liquid crystal molecule 30a and have relation between the surface structure of perpendicular alignmnet power with reference to figure 27A-27D.

As institute's diagram among Figure 27 A, regulate power (being generally perpendicular alignmnet film surface) owing to have the orientation on the surface of perpendicular alignmnet power, the liquid crystal molecule 30a on the horizontal surface aims at perpendicular to this surface.When providing the electric field of representing with equipotential line EQ by vertically aligned liquid crystal molecule 30a, wherein equipotential line EQ is perpendicular to the axle orientation of liquid crystal molecule 30a, impel liquid crystal molecule 30a clockwise direction moment of torsion that tilts and the moment of torsion that impels liquid crystal molecule 30a counterclockwise to tilt, act on the liquid crystal molecule 30a with equal probabilities.Therefore, comprise some liquid crystal molecule 30a in the liquid crystal layer 30 between a pair of comparative electrode of arranging with parallel-plate, it is subjected to the clockwise direction torsional interaction, also comprises other liquid crystal molecule 30a, and it is subjected to torsional interaction counterclockwise.Therefore, according to the voltage that is applied on the liquid crystal layer 30, the orientation transition can not steadily be carried out smoothly.

As the diagram of Figure 27 B institute, when the liquid crystal molecule 30a of the electric field of being represented by horizontal equipotential line EQ by the perpendicular alignmnet inclined surface applied, liquid crystal molecule 30a was needing littler inclination with the either direction that is parallel to equipotential line EQ tilt (being clockwise direction in the illustrated example) for liquid crystal molecule 30a.Then, as the diagram of Figure 27 C institute, other adjacent lcd molecule 30a perpendicular to the surface level aligning, with be positioned at inclined surface on the identical direction of liquid crystal molecule 30a tilt (clockwise direction) orientation continuous (consistent) of its orientation and the liquid crystal molecule 30a that aims at perpendicular to inclined surface thus.

As the diagram of Figure 27 D institute, comprise a series of trapezoidal surfaces for its xsect with recessed/bossing, liquid crystal molecule 30a on the orientation upper surface and the liquid crystal molecule 30a on the lower surface are so that consistent with the direction of orientation of being regulated by other liquid crystal molecule 30a on the surface inclined portions.

In liquid crystal indicator 200, the direction that the orientation that is applied by surface structure (giving prominence to) is regulated power becomes aligning with the direction that the orientation that is applied by tilting electric field is regulated power, stablizes radial skew thus and is orientated.

Figure 28 A and 28B illustrate the state that impressed voltage is arranged on the liquid crystal layer shown in Figure 26 B 30.Figure 28 A schematically illustrates the orientation of liquid crystal molecule 30a according to the voltage that applies on the liquid crystal layer 30, just begun the state (initial turn-on state) that changes, the orientation that Figure 28 B schematically illustrates liquid crystal molecule 30a has changed and the stable status that becomes according to the voltage that applies.In Figure 28 A and 28B, curve EQ represents equipotential line.

As the diagram of Figure 26 B institute, when pixel electrode 14 and counter electrode 22 were in same potential (just, being in does not have voltage to be applied to state on the liquid crystal layer 30), the liquid crystal molecule 30a in each pixel region aimed at perpendicular to substrate 11 and 21 surfaces.The liquid crystal molecule 30a that contacts with perpendicular alignmnet film (not shown) on the outstanding 40 side surface 40s, aim at perpendicular to side surface 40s, because with the interaction of liquid crystal molecule 30a on every side (as the person's character of elastic continuum), near the liquid crystal molecule 30a the side surface 40s gets graphic tilted alignment.

When voltage is applied on the liquid crystal layer 30, produce the potential gradient of representing by equipotential line EQ shown in Figure 28 A.In the solid portion 14b and zone counter electrode 22 between of liquid crystal layer 30 at pixel electrode 14, equipotential line EQ is parallel to the surface of solid portion 14b and counter electrode 22, and with the corresponding zone of opening 14a of pixel electrode 14 in descend, therefore, produce the tilting electric field that equipotential line EQ sloping portion is represented, in its liquid crystal layer 30 on the EG of opening 14a marginal portion (comprising its border in opening 14a periphery and the opening 14a).

Because tilting electric field, as mentioned above, shown in the arrow among Figure 28 A, liquid crystal molecule 30a clockwise direction on the right hand edge part EG among Figure 28 A tilts (rotation) and liquid crystal molecule 30a on the left hand edge part EG counterclockwise tilts (rotation), so that be parallel to equipotential line EQ.The direction of the orientation adjusting power that tilting electric field applies is identical with the direction that the orientation that the side surface 40s that is positioned at each marginal portion EG applies is regulated power.

As mentioned above, the liquid crystal molecule 30a of the variation of orientation from the sloping portion that is positioned at equipotential line EQ, and reach the orientation stable state of Figure 28 B schematic illustration.Liquid crystal molecule 30a around the opening 14a core, liquid crystal molecule 30a around the just outstanding 40 upper surface 40t cores, basically equally be subjected to the influence of each orientation of liquid crystal molecule 30a on the opening 14a opposite edges part EG, the orientation that therefore keeps them is perpendicular to equipotential line EQ.Away from the liquid crystal molecule 30a at opening 14a center (outstanding 40 upper surface 40t) be subjected to keeping to the side other liquid crystal molecule 30a orientation on the part EG influence and tilt, form a tilted alignment thus, it is about opening 14a center SA (outstanding 40 upper surface 40t) symmetry.Corresponding to the tilted alignment symmetry that also forms in basically by the zone of opening 14a and the outstanding 40 solid portion 14b ' of unit that surround about the solid portion 14b ' center SA of unit.

As mentioned above, corresponding with the solid portion 14b ' of unit as in liquid crystal indicator 100 in liquid crystal indicator 200 with opening 14a, form liquid crystal territory with radial skew orientation.Owing to provide outstanding 40,, form each liquid crystal territory with corresponding by the outstanding 40 general border circular areas that surround so that in general circular pattern, surround each solid portion 14b ' of unit fully.And, the side surface that is arranged on outstanding 40 among the opening 14a be used near the beveled 14a marginal portion EG liquid crystal molecule 30a for and the orientation that applies by tilting electric field regulate the identical direction of direction of power, stablize radial skew thus and be orientated.

Certainly, the orientation power of regulating that is applied by tilting electric field only works when having impressed voltage, and its intensity depends on electric field intensity (level of impressed voltage).Therefore, when electric field intensity hour (just when impressed voltage is low), a little less than the orientation adjusting power that tilting electric field applies, in this case, when stress during in liquid crystal board, because the drift of liquid crystal material, the radial skew orientation may be damaged.In case radial skew orientation is damaged, produce a tilting electric field it just recovers up to applying enough voltage, this tilting electric field applies fully strong orientation and regulates power.On the other hand, no matter the voltage that applies, apply from the orientation of outstanding 40 side surface 40s and regulate power, just as is known to the person skilled in the art, it is very strong as " cementation effect (anchoringeffect) " of aligning film.Therefore, in case even when drift appears in liquid crystal material and radial skew orientation when damaging, near the liquid crystal molecule 30a in outstanding 40 the side surface 40s keeps being orientated identical direction of orientation with radial skew.Therefore, in case the liquid crystal material drift stops, the radial skew orientation is recovered easily.

Therefore, except the advantage of liquid crystal indicator 100, liquid crystal indicator 200 has other strong anti-stress advantage.Therefore, liquid crystal indicator 200 can suitably be used for often suffering the device of stress, for example PC and the PDA that often carries everywhere.

When outstanding 40 usefulness high grade of transparency dielectric substances are made, obtain to improve the advantage of a liquid crystal territory demonstration effect, this liquid crystal territory be formed on the corresponding zone of opening 14a in.When the opaque dielectric substance of outstanding 40 usefulness was made, because outstanding 40 side surface 40s, the advantage of acquisition was the light leak that possible stop the delay by the liquid crystal molecule 30a of tilted alignment to cause.Being to use transparent dielectric material still is opaque dielectric substance, for example can according to liquid crystal indicator should be used for determine.In arbitrary situation, the advantage of using photosensitive resin to provide be can simplify to the step of accordingly outstanding 40 pattern-makings of opening 14a.Regulate power in order to obtain enough orientations, when the thickness of liquid crystal layer 30 was about 3 μ m, outstanding 40 height preferably was about the about 2 μ m of 0.5 μ m-.Usually, outstanding 40 height preferably is about the 1/6-2/3 of liquid crystal layer 30 thickness.

As mentioned above, liquid crystal indicator 200 is included in outstanding 40 among the opening 14a of pixel electrode 14, for the liquid crystal molecule 30a of liquid crystal layer 30, outstanding 40 side surface 40s applies orientation adjusting power in the direction identical with the orientation adjusting power that is applied by tilting electric field.Describe side surface 40s referring now to Figure 29 A-29C and apply the optimum condition that the orientation that applies with tilting electric field is regulated the identical orientation adjusting power of force direction.

Figure 29 A-29C is the cross-sectional view of diagram liquid crystal indicator 200A, 200B and 200C schematically respectively.Figure 29 A-29C is corresponding with Figure 28 A. Liquid crystal indicator 200A, 200B and 200C have outstanding in opening 14a, but aspect the position relation between whole outstanding 40 and the corresponding opening 14a of single structure, are different from liquid crystal indicator 200.

In above-mentioned liquid crystal indicator 200, as the diagram of Figure 28 A institute, be formed among the opening 14a as whole outstanding 40 of a structure, outstanding 40 lower surface is less than opening 14a.In the graphic liquid crystal indicator 200A of Figure 29 A, the lower surface of outstanding 40A is aimed at opening 14a.In the graphic liquid crystal indicator 200B of Figure 29 B, the lower surface of outstanding 40B is greater than opening 14a, so that cover part solid portion (conducting film) 14b that surrounds opening 14a.That solid portion 14b is not formed on is outstanding 40, among 40A and the 40B on any one side surface 40s.Therefore, graphic as institute among each figure, equipotential line EQ is flat basically on solid portion 14b, and falls into opening 14a.Therefore, side surface 40s as the outstanding 40B of the side surface 40s of the outstanding 40A of outstanding 40, the liquid crystal indicator 200A of liquid crystal indicator 200 and liquid crystal indicator 200B, all apply direction and regulate the identical orientation adjusting power of force direction, stablize the radial skew orientation thus with the orientation that applies by tilting electric field.

On the contrary, in the graphic liquid crystal indicator 200C of 29C, the lower surface of outstanding 40C is greater than opening 14a, and the part solid portion 14b that extends into opening 14a upper zone is formed on the outstanding 40C side surface 40s.Owing to be formed on the influence of the part solid portion 14b on the side surface 40s, in equipotential line EQ, set up spine.The spine of equipotential line EQ has and the opposite gradient of equipotential line EQ other parts that falls into opening 14a.This expression has produced a tilting electric field, and its direction is opposite with the direction of the tilting electric field that liquid crystal molecule 30a is oriented to the radial skew orientation.Therefore, regulate the identical orientation adjusting power of force direction for side surface 40s is had with the orientation that is applied by tilting electric field, preferably solid portion (conducting film) 14b is not formed on the side surface 40s.

Secondly, will 40 the cross-sectional structure given prominence to along the line 30A-30A ' of Figure 26 A be described with reference to Figure 30.

As mentioned above, owing to form Figure 26 A graphic outstanding 40 so that surround each solid portion 14b ' of unit fully in general circular pattern, the part (from the component of circular portion to the four direction extension) that is used for adjacent cells solid portion 14b ' is linked together is formed on Figure 30 institute graphic outstanding 40.Therefore, in the step of deposit, there is sizable possibility, disconnects exactly and may appear on outstanding 40 or layering may appear in the product post processor as the conducting film of the solid portion 14b of pixel electrode 14.

Consider this, in Figure 31 A and the graphic liquid crystal indicator 200D of Figure 31 B, form separate outstanding 40D, make each outstanding 40D be completely contained in the opening 14a, the conducting film that will become solid portion 14b thus is formed on the plane surface of substrate 11, has eliminated the possibility of disconnection or layering thus.Though outstanding 40D can not be fully enclosed in each the solid portion 14b ' of unit in the general circular pattern, but form corresponding general circular liquid crystal territory with each solid portion 14b ' of unit, and as in above-mentioned example, stablize the radial skew orientation of the solid portion 14b ' of unit.

Be not limited to the pattern of above-mentioned opening 14a by the effect that in opening 14a, forms the outstanding 40 stable radial skew orientations that obtain, but can use above-mentioned any opening 14a pattern similarly, so that obtain aforesaid effect.In order to make outstanding 40 effects of using stable orientations fully resist stress, outstanding 40 pattern (as from the observed pattern of substrate normal direction) covering liquid crystal layer 30 as much as possible preferably.Therefore, for example compare, use positive pattern, can obtain bigger outstanding 40 orientation stablizing effect with circular solid portion 14b ' of unit with the negative pattern that use has a circular open 14a.

Use the above-mentioned pixel capacitors structure that opening wherein is provided in pixel capacitors, enough voltage can not be applied to the corresponding zone of opening in liquid crystal layer on, can not obtain enough delay and change, reduce light efficiency thus.Consider this, provide one deck dielectric layer having on the side of the pixel electrode of opening (top electrode) away from liquid crystal layer, provide a supplemantary electrode (bottom electrode) via this dielectric layer, so that it is to the relative pixel electrode opening of small part (just can use two-layer electrode).Like this, may with opening corresponding liquid crystal layer on apply enough voltage, improve light efficiency and/or response characteristic thus.

Each of Figure 32 A-32C is the cross-sectional structure that schematically illustrates a pixel region of liquid crystal indicator 300, it has pixel electrode 15 (two-layer electrode), and this electrode 15 comprises that a bottom electrode 12, a top electrode 14 and are arranged on the dielectric layer 13 between them.The top electrode 14 of pixel electrode 15 is equivalent to above-mentioned pixel electrode 14 basically, comprises having above-mentioned any difformity and being arranged in opening and the solid portion with any different pattern.Now description had the function of the pixel electrode 15 of double-layer structure.

The pixel electrode 15 of liquid crystal indicator 300 comprises a plurality of opening 14a (comprising 14a1 and 14a2).Figure 32 A schematically illustrates when not having impressed voltage, the orientation of liquid crystal molecule 30a (off state) in the liquid crystal layer 30.Figure 32 B schematically illustrates a kind of state, and wherein according to the voltage that is applied on the liquid crystal layer 30, the orientation of liquid crystal molecule 30a has just begun to change (initial turn-on state).Figure 32 C schematically illustrates a kind of state, and wherein according to the voltage that applies, the orientation of liquid crystal molecule 30a has changed and become stable.In Figure 32 A-32C, provide bottom electrode 12 so that via dielectric layer 13 relative opening 14a1 and 14a2, bottom electrode 12 overlapping opening 14a1 and 14a2, and also extend in the zone between opening 14a1 and 14a2 (zone that top electrode exists).Yet the arrangement of bottom electrode 12 is not limited to this, but as selection, for each opening 14a1 and 14a2, arrangement can be like this, is exactly the area of the area=opening 14a of bottom electrode 12, or the area of the area of bottom electrode 12＜opening 14a.Therefore, need only bottom electrode 12 via dielectric layer 13 relative at least a portion opening 14a, the structure of bottom electrode 12 just is not limited to any ad hoc structure.Yet, in the time of in bottom electrode 12 is arranged on opening 14a, there is a zone (interstitial area), wherein bottom electrode 12 still is that top electrode 14 does not appear at from perpendicular to the observed plane of the direction of substrate 11.Enough voltage may not be applied on the liquid crystal layer 30 in the zone relative with interstitial area.Therefore, for the orientation of stabilizing solution crystal layer 30, preferably fully reduce the interstitial area width.Usually, preferably the interstitial area width is no more than about 4 μ m.And the bottom electrode 12 that is arranged on a certain position is basically to being applied to the not influence of electric field on the liquid crystal layer 30, and this position makes its zone via the conductive layer existence of dielectric layer 13 relative top electrodes 14.Therefore, can or can be not to this bottom electrode 12 pattern-makings.

Graphic as institute among Figure 32 A, when pixel electrode 15 and counter electrode 22 are positioned at same potential (not applying the state of voltage on liquid crystal layer 30), the liquid crystal molecule 30a in the pixel region aims at perpendicular to the surface of substrate 11 and 21.Here, for simply, suppose that the top electrode 14 of pixel electrode 15 and bottom electrode 12 are positioned at same potential.

When on liquid crystal layer 30, applying voltage, produced the potential gradient of representing by the equipotential line EQ shown in Figure 32 B.In the top electrode 14 and the liquid crystal layer 30 in the zone between the counter electrode 22 of pixel electrode 15, produce the uniform potential gradient that the equipotential line EQ by the surface that is parallel to top electrode 14 and counter electrode 22 represents.Liquid crystal layer 30 zones on opening 14a1 that is arranged in top electrode 14 and 14a2 produce the potential gradient according to electric potential difference between bottom electrode 12 and the counter electrode 22.Because dielectric layer 13, the potential gradient that produces in the liquid crystal layer 30 is subjected to the influence of pressure drop, thus, with opening 14a1 and the corresponding zone of 14a2 in, the equipotential line EQ in the liquid crystal layer 30 descend (in equipotential line EQ, setting up a plurality of " groove (trough) ").Owing in the zone relative with opening 14a1, provide bottom electrode 12 with 14a2 via dielectric layer 13, liquid crystal layer 30 around the core separately of opening 14a1 and 14a2 also has a potential gradient, and it represents (during equipotential line EQ " bottom land ") with the part equipotential line EQ that is parallel to top electrode 14 and counter electrode 22 planes.Produce in the liquid crystal layer 30 of the tilting electric field of representing by the sloping portion of equipotential line EQ on each opening 14a1 and 14a2 marginal portion EG (comprising in the opening on its border and periphery).

Clearly the contrast between Figure 32 B and Fig. 2 A find out because liquid crystal indicator 300 has bottom electrode 12, enough electric fields also can act on be formed on the corresponding zone of opening 14a in the liquid crystal territory in liquid crystal molecule on.

One torsional interaction has on the liquid crystal molecule 30a of negative dielectric anisotropic, so that the axle orientation of guiding liquid crystal molecule 30a is parallel to equipotential line EQ.Therefore, shown in arrow among Figure 32 B, liquid crystal molecule 30a clockwise direction on the right hand edge part EG among Figure 32 B tilts (rotation) and liquid crystal molecule 30a on the left hand edge part EG counterclockwise tilt (rotation).Therefore, to be parallel to equipotential line EQ partially oriented accordingly for the liquid crystal molecule 30a on the EG of marginal portion.

Graphic as Figure 32 B institute, when on the marginal portion EG of the opening 14a1 of liquid crystal indicator 300 and 14a2, producing the electric field (tilting electric field) that the equipotential line EQ that uses to tilt about liquid crystal molecule 30a axle orientation partly represents, graphic as Fig. 3 B institute, liquid crystal molecule 30a tilt in any direction (in the graphic example be counterclockwise), for liquid crystal molecule 30a, this direction needs rotation still less is so that be parallel to equipotential line EQ.Graphic as Fig. 3 C institute, liquid crystal molecule 30a in the zone that has produced the electric field of being represented by the equipotential line EQ perpendicular to liquid crystal molecule 30a axle orientation is tilting with the liquid crystal molecule 30a equidirectional that is positioned on the equipotential line EQ sloping portion, thus its orientation be positioned at equipotential line EQ sloping portion on the orientation continuous (consistent) of liquid crystal molecule 30a.

The change in orientation of liquid crystal molecule 30a, from being positioned at the liquid crystal molecule 30a on the equipotential line EQ sloping portion, proceed as mentioned above, as schematic illustration among Figure 32 C, reach stable state, just about the tilted alignment (radial skew orientation) of the center SA symmetry of each opening 14a1 and 14a2.Liquid crystal molecule 30a in top electrode 14 zones between two adjacent apertures 14a1 and 14a2 also gets a tilted alignment, make its orientation be positioned at opening 14a1 and 14a2 marginal portion on the orientation continuous (consistent) of liquid crystal molecule 30a.The liquid crystal molecule 30a of the centre between opening 14a1 edge and opening 14a2 edge, be subjected to from the substantially the same influence of liquid crystal molecule 30a on each marginal portion, therefore keep as be positioned at liquid crystal molecule 30a perpendicular alignmnet around each the core of opening 14a1 and 14a2.Therefore, the liquid crystal layer on the top electrode 14 between adjacent two opening 14a1 and the 14a2 is also got the radial skew orientation.Note, between the radial skew of liquid crystal layer is orientated between the radial skew of liquid crystal layer orientation and opening 14a1 and the 14a2 among each opening 14a1 and the 14a2, liquid crystal molecules tilt direction difference.Liquid crystal molecule 30a orientation on every side with each regional center of the graphic radial skew orientation of Figure 32 C is observed expression, liquid crystal molecule 30a in opening 14a1 and the 14a2 zone is tilted, so that form towards the taper shape of counter electrode expansion, and the liquid crystal molecule 30a in the zone is tilted between the opening, so that form towards the taper shape of top electrode 14 expansions.Because this two kinds of radial skews orientation all is formed, so as consistent with liquid crystal molecule 30a radial skew orientation on the marginal portion, so two radial skews orientations are continuous mutually.

As mentioned above, when applying voltage on liquid crystal layer 30, opening 14a1 and the liquid crystal molecule 30a separately marginal portion EG of 14a2 on of liquid crystal molecule 30a from be provided at top electrode 14 begins to tilt.Then, liquid crystal molecule 30a in the peripheral region tilts, so that consistent with the tilted alignment of liquid crystal molecule 30a on the EG of marginal portion.Thereby form radial skew orientation.Therefore, when the quantity of the opening 14a in being arranged on each pixel region increased, the liquid crystal molecule 30a quantity that the electric field that response applies begins to tilt at first also increased, and reduces thus and realize the required time quantum of radial skew orientation on whole pixel region.Therefore,, be arranged on opening 14a quantity in the pixel electrode 15, may improve the response speed of liquid crystal indicator by increase for each pixel region.And the two-layer electrode that comprises top electrode 14 and bottom electrode 12 by use is as pixel electrode 15, enough electric fields also can act on the corresponding zone of opening 14a in liquid crystal molecule on, improve the response characteristic of liquid crystal indicator thus.

And, by providing outstanding setting off by contrast at the end, cooperating with the orientation adjustment structure (the aforesaid electrode structure that wherein has opening) of TFT substrate becomes the radial skew orientation to liquid crystal molecular orientation, can further stablize the orientation of getting the liquid crystal territory that radial skew is orientated.

Figure 33 A and 33B illustrate liquid crystal indicator 400, and it comprises being arranged on and sets off by contrast outstanding 28 on the end 400b.Figure 33 A is a planimetric map, and Figure 33 B is the cross-sectional view along the line 33B-33B ' of Figure 33 A.

Liquid crystal indicator 400 comprise TFT substrate 100a with pixel electrode 14 and have outstanding 28 set off by contrast end 400b, in pixel electrode 14, form opening 14a, outstanding 28 is outstanding towards liquid crystal layer 30.Notice that TFT substrate 100a is not limited to graphic arrangement, but can be any one of above-mentioned various arrangements as selecting.

Be arranged on each of setting off by contrast on the end 400b and outstanding 28 have side surface 28s, it tilts about the substrate plane (substrate plane of transparent substrates 11) of setting off by contrast end 400b, and in illustrated example, outstanding 28 are formed on the counter electrode 22.

Each surface of outstanding 28 has perpendicular alignmnet power (usually, forming perpendicular alignmnet film (not shown) so that cover outstanding 28), and as the diagram of Figure 33 B institute, because the cementation effect of side surface 28s, liquid crystal molecule 30a is substantially perpendicular to side surface 28s and aims at.Therefore, the liquid crystal molecule 30a around outstanding 28 is about outstanding 28 tilted alignments radially.Like this, outstanding 28 rely on its surface structure (having perpendicular alignmnet power), and liquid crystal molecule 30a is oriented to the radial skew orientation.

And outstanding 28 are arranged in the zone relative with the solid portion 14b of pixel electrode 14, and outstanding 28 cores that make its relative unit solid portion 14b ' especially are set.This arrangement for outstanding 28, because the outstanding 28 liquid crystal molecules tilt directions that cause, by the orientation adjustment structure, to aim at the direction of orientation of liquid crystal territory radial skew orientation, this liquid crystal territory is formed on and the solid portion 14b ' of unit of pixel electrode 14 accordingly in the zone.Because no matter whether impressed voltage exists, outstanding 28 apply orientation adjusting power, can obtain stable radial skew orientation on any gray level, and desirable anti-stress ability can be provided equally.

As mentioned above, in liquid crystal indicator 400, by being orientated the radial skew direction of orientation that adjustment structure forms, with aim at by the outstanding 28 radial skew directions of orientation that form, thus, when on liquid crystal layer 30, having impressed voltage, just, when between pixel electrode 14 and counter electrode 22, having impressed voltage, stablize the radial skew orientation.This schematically is illustrated in Figure 34 A-34C.Figure 34 A illustrates the state that does not have impressed voltage, and Figure 34 B illustrates the impressed voltage rear to the state (initial turn-on state) that just begins to change, and Figure 34 C schematically illustrates the stable state that applies during the voltage.

As the diagram of Figure 34 A institute, even when not having impressed voltage, regulate on the power effect liquid crystal molecule 30a in its vicinity, form the radial skew orientation thus by outstanding 28 orientations that apply.

When voltage applies beginning, produced the electric field of representing by equipotential line EQ shown in Figure 34 B (by the orientation adjustment structure), the liquid crystal territory that liquid crystal molecule 30a is in radial skew orientation be formed on corresponding each zone of opening 14a and with corresponding each zone of solid portion 14b in, as the diagram of Figure 34 C institute, liquid crystal layer 30 reaches stable state.Be formed on the corresponding zone of solid portion 14b in each liquid crystal territory in vergence direction and certain direction of liquid crystal molecule 30a consistent, on this direction, the outstanding 28 orientation adjusting power that apply that are arranged in the respective regions tilt liquid crystal molecule 30a.

When a stress is applied on the liquid crystal indicator 400 that is in stable state, the radial skew orientation of liquid crystal layer 30 was once damaged, but after eliminating stress, the radial skew orientation is restored, and is used on the liquid crystal molecule 30a because come the orientation of auto-orientation adjustment structure and outstanding 28 to regulate masterpiece.Therefore, suppressed the after image that occurs owing to stress.

Notice that outstanding 28 orientation adjusting power is unnecessary very strong, stablize radial skew orientation that forms by the orientation adjustment structure and the effect of fixing its central shaft position because it only need have.For example, for the solid portion 14b ' of unit of the about 50 μ m of the about 30-of diameter, obtain enough orientation adjusting power by forming outstanding 28 of the about 15 μ m of diameter and height (thickness) about 1 μ m.

Though outstanding 28 material is not limited to any special material, but by use dielectric substance for example resin can form outstanding 28 easily.And, the preferred resin material that adds thermal deformation that uses, in this case, after forming pattern by heat treated, may form easily outstanding 28, its have as Figure 33 B the xsect of graphic slight protuberance.(along the substrate plane normal) has outstanding 28 ideal roles that fixed radial tilted alignment center is provided of the xsect of slight protuberance, and this xsect has as graphic summit among the figure.Certainly, can have top surface as selecting to give prominence to.

And, though it is outstanding 28 of general circle that Figure 33 A illustrates its xsect (along the substrate plane of setting off by contrast end 400b), but outstanding 28 shape of cross section is not limited to this, and as selection, outstanding 28 can have general rectangular cross section or general cross-like cross-section.In order to reduce view angle dependency, outstanding 28 preferably have highly rotational symmetric shape of cross section.

Figure 35 illustrates the liquid crystal indicator 400A that comprises the outstanding 28A with general cross-like cross-section.Except outstanding 28A has the general cross-like cross-section, liquid crystal indicator 400A has basically the structure identical with the graphic liquid crystal indicator of Figure 33 A and 33B 400.

Compare with having general circular cross section and have the outstanding of roughly the same area, outstanding 28A with general cross-like cross-section has bigger inclined side, it applies orientation adjusting power on liquid crystal molecule 30a, and should outstanding 28A can be in the liquid crystal territory than large tracts of land on apply orientation adjusting power.Therefore, may more effectively on liquid crystal molecule 30a, apply orientation adjusting power.Thereby what the liquid crystal indicator 400A that includes the outstanding 28A of general cross-like cross-section had more stable orientation and a raising applies response speed to voltage.

Certainly, may use a kind of arrangement, wherein the outstanding of varying cross-section shape (along substrate plane) be arranged setting off by contrast at the end.For example, can be provided with and have bigger orientation and regulate the orientation that outstanding (for example graphic outstanding 28A with general cross-like cross-section among Figure 35) of power improve in some zones and regulate power, in these zones, near the unnecessary electric field (for example bus) that negative effect shows may appear, and in other zone, provide to have the outstanding of varying cross-section shape.

Figure 36 and Figure 37 illustrate liquid crystal indicator 40013 and 400C respectively, and they comprise the outstanding of varying cross-section shape setting off by contrast on the end 400b.

The TFT substrate of the graphic liquid crystal indicator 400B of Figure 36 comprises pixel electrode 14, wherein part unit's solid portion 14b ' (shape is corresponding with about half solid portion 14b ' of unit) arranges along grid bus 15, as Figure 21 A and the graphic liquid crystal indicator 100E of 21B.The end of setting off by contrast of liquid crystal indicator 400B, comprise, has the outstanding 28B of general T shape xsect accordingly in each zone with the solid portion 14b ' of part unit that arranges along grid bus 15, and be included in and the solid portion 14b ' of unit accordingly in each zone, have outstanding 28 of general circular cross section.

The direction that liquid crystal molecule 30a is tilted by the outstanding 28B of general T shape, aim at this liquid crystal territory and the corresponding formation of the solid portion 14b ' of part unit that arranges along grid bus 15 (shape is corresponding with about half solid portion 14b ' of unit) with the direction of orientation that the radial skew in part liquid crystal territory is orientated.The general T shape that correspondingly provides with the solid portion 14b ' of part unit (shape is corresponding with about half solid portion 14b ' of unit) is given prominence to 28B, can on liquid crystal molecule 30a, apply bigger orientation effectively and regulate power, reason be arranged on the solid portion 14b ' of unit accordingly the general circle in each zone to give prominence to 28A identical.

Therefore, has among the liquid crystal indicator 400B that outstanding 28B that bigger orientation regulates power arranges along grid bus 15 orientation of the liquid crystal molecule 30a that arranges along grid bus 15 that may regulate effectively that its orientation may be interfered therein.

The TFT substrate of the graphic liquid crystal indicator 400C of Figure 37 comprises that wherein part unit's solid portion 14b ' (shape is corresponding with about half solid portion 14b ' of unit) is along grid bus 15 and source bus line 16 arranged pixel electrodes 14, as the graphic liquid crystal indicator 100G of Figure 23.The end of setting off by contrast of liquid crystal indicator 400C, comprise, have the outstanding 28B of general T shape xsect in each zone accordingly with the solid portion 14b ' of part unit that arranges along grid bus 15 and source bus line 16, and be included in the solid portion 14b ' of unit and have outstanding 28 of general circular cross section in each zone accordingly.

The outstanding 28B that has bigger orientation adjusting power therein may regulate along the orientation of the liquid crystal molecule 30a of grid bus 15 and source bus line 16 layouts effectively along among the liquid crystal indicator 400C of grid bus 15 and source bus line 16 layouts.

The arrangement of polarization plates and phase-plate

So-called " perpendicular alignmnet type liquid crystal indicator " comprises the vertically aligned liquid crystal layer of the liquid crystal molecule that has negative dielectric anisotropic when wherein not having impressed voltage, and this device can be with various display mode display images.For example, except birefringent mode, can use perpendicular alignmnet type liquid crystal indicator with an optically-active pattern or a display mode, this display mode is the combination of an optically-active pattern and a birefringence pattern, and birefringent mode is to come display image by the birefringence of using the electric field controls liquid crystal layer.By on the outside (away from the side of liquid crystal layer 30) of a pair of substrate of above-mentioned any liquid crystal indicator (for example TFT substrate and set off by contrast at the end), a pair of polarization plates being set, may obtain the liquid crystal indicator of birefringent mode.And, can be provided with if desired and differ compensator (normally phase-plate).In addition, same by using the light of common circular polarization, can obtain the high brightness liquid crystal indicator.

Another alternate embodiment

Because the reduction of the display quality that near produce the bus edge tilting electric field causes not only appears in have the orientation adjustment structure liquid crystal indicator of (electrode with unit solid portion and opening), this orientation adjustment structure is used to form the liquid crystal territory of getting the radial skew orientation, and appear in the liquid crystal indicator that generally includes perpendicular alignmnet type liquid crystal layer, when not having impressed voltage, this liquid crystal layer perpendicular alignmnet, these liquid crystal indicators are regulated orientation by using the electrode structure that wherein has opening.

Use the present invention, may improve and generally include perpendicular alignmnet type liquid crystal layer and by using the electrode structure that wherein has opening to regulate display quality in the liquid crystal indicator of orientation.

The structure of the liquid crystal indicator 500 of another alternate embodiment according to the present invention will be described with reference to figure 38A and 38B.Figure 38 A is the planimetric map of observing from the substrate normal direction, and Figure 38 B is the cross-sectional view along the line 38B-38B ' of Figure 38 A.Figure 38 A and 38B illustrate voltage and are applied to state on the liquid crystal layer.

Liquid crystal indicator 500 comprises active matrix substrate (hereinafter referred to as " TFT substrate ") 500a, sets off by contrast at the end (being also referred to as " color filter substrate ") 500b and is arranged on TFT substrate 500a and set off by contrast the liquid crystal layer 30 between the end 500b.

The liquid crystal molecule 30a of liquid crystal layer 30 has negative dielectric anisotropic, when liquid crystal layer 30 does not have impressed voltage, dependence is arranged on TFI substrate 500a as vertical alignment layer and sets off by contrast lip-deep perpendicular alignmnet film (not shown) of each the close liquid crystal layer 30 among the end 500b, and liquid crystal molecule 30a aims at perpendicular to perpendicular alignmnet film surface.

The TFT substrate 500a of liquid crystal indicator 500 comprises transparent substrates (for example glass substrate) 11 and pixel electrode 19, and it is arranged on transparent substrates 11 surfaces.Set off by contrast end 500b and comprise transparent substrates (for example glass substrate) 21 and counter electrode 22, it is arranged on the surface of transparent substrates 21.For each pixel region, the orientation of liquid crystal layer 30 changes according to the voltage that is applied between pixel electrode 19 and the counter electrode 22, arranges pixel electrode 19 and makes them relative mutually via liquid crystal layer 30 with counter electrode 22.Show that by utilizing a kind of phenomenon to produce this phenomenon is that the light polarization or the light quantity of passing liquid crystal layer 30 change along with the change in orientation of liquid crystal layer 30.

The pixel electrode 19 of TFT substrate 500a comprises a plurality of opening 19a and a solid portion 19b.Opening 19a is meant the part of the pixel electrode of being made by conducting film (for example ITO film) 19, has removed conducting film in this part, and solid portion 19b is meant partial pixel electrode 19, wherein has conducting film (part except that opening 19a).Though for each pixel electrode, form a plurality of opening 19a, but solid portion 19b is made by monolithic continuous conduction film basically.

In the present embodiment, each opening 19a has fracture shape (just width is significantly less than the shape (width is perpendicular to the size on the length direction) of its length).Each opening 19a has the side, and it extends on about pixel region long side surface and short side (column direction and line direction that matrix pattern is arranged) angular direction at 45.And the side differs 90 ° in pixel region the first half direction of extending and the direction of extending in pixel region the latter half.

When between pixel electrode 19 and counter electrode 22, applying voltage, (comprise in the opening 19a periphery and opening 19a on its border) in the liquid crystal layer 30 on the opening 19a marginal portion of pixel electrode 19 having produced the tilting electric field of representing by the equipotential line EQ sloping portion that inclines.Therefore, have the liquid crystal molecule 30a of negative dielectric anisotropic, their perpendicular alignmnets when not having impressed voltage are tilted the vergence direction that results from the tilting electric field on the opening 19a marginal portion for the edge.Thereby when applying voltage between pixel electrode 19 and counter electrode 22, the tilting electric field that the orientation of liquid crystal layer 30 is created within on each opening 19a marginal portion of pixel electrode 19 is regulated.

In liquid crystal indicator 500, the tilting electric field that the orientation of liquid crystal layer 30 is resulted from the opening 19a marginal portion is regulated, and the liquid crystal molecule 30a in the pixel region is orientated on four different azimuth directions thus, and they are positioned on the angle that is in 90 ° of integral multiples.In other words, in liquid crystal indicator 500, pixel region has the multiple domain orientation.Therefore, liquid crystal indicator 500 has desirable viewing angle characteristic.

And the end 500b that sets off by contrast of liquid crystal indicator 500 gives prominence to 29 at it near comprising on the surface of liquid crystal layer 30.As observed on the substrate normal direction, each is given prominence to 29 and has inclined side surfaces 29s, and is formed in the crenellation pattern (or "＞" shape pattern).The direction that side surface 29s extends is consistent with the direction that extend opening 19a side, is provided with outstanding 29 and makes its centre that is located substantially on two opening 19a, these two opening 19a mutual adjacent arrangement on their Widths.

Outstanding 29 surface has a perpendicular alignmnet power (usually, forming a perpendicular alignmnet film (not shown) so that it covers outstanding 29), because the cementation effect of side surface 29s, liquid crystal molecule 30a is substantially perpendicular to side surface 29s and aims at.When voltage was applied on the liquid crystal layer 30 that is in this state, because the cementation effect of outstanding 29 inclined side surfaces 29s, other liquid crystal molecule 30a around outstanding 29 tilted, so that to go up the tilted alignment of liquid crystal molecule 30a consistent with inclined side surfaces 29s.

Because resulting from the orientation of tilting electric field of the opening 19a marginal portion of pixel electrode 19 regulates direction and aims at outstanding 29 orientation adjusting direction, the orientation of outstanding 29 further stabilizing solution crystal layers, when having impressed voltage, tilting electric field becomes the multiple domain orientation to liquid crystal layer.

The TFT substrate 500a of liquid crystal indicator 500 comprises TFT (not shown) and the bus 18 that is electrically connected to pixel electrode 19 as on-off element, and bus 18 comprises grid bus (sweep trace) 15 and source bus line (signal wire) 16, and they are electrically connected to TFT.

In the present embodiment, as the diagram of Figure 38 A institute, form the opening 19a of pixel electrode 19, make them can not be at grid bus 15 edges, the edge of grid bus 15 be covered by the solid portion 19b of pixel electrode 19.Therefore, realized high-quality demonstration.To this reason be described with reference to figure 38A, 38B and Figure 39.Figure 39 is the planimetric map of diagram liquid crystal indicator 800 schematically, and wherein grid bus 15 part edges are not covered by the solid portion 19b of pixel electrode 19.

One tilting electric field is created near bus 18 edges, no matter have/do not have impressed voltage on the liquid crystal layer 30 between pixel electrode 19 and the counter electrode 22, all produces described tilting electric field.Therefore, producing in the liquid crystal indicator that shows with common black mode, if there is not impressed voltage, by near the liquid crystal molecule 30a orientation adjusting power inclination bus 18 edges of tilting electric field, light leak may occur, and reduces contrast ratio thus.Especially, keep TFT to turn-off because 15 mosts of the time of grid bus apply high relatively voltage (shutoff voltage), near grid bus 15 edges, this light leak degree is tangible.

As the diagram of Figure 39 institute, in liquid crystal indicator 800, pixel electrode 19 comprises opening 19a, form opening 19a and make it at grid bus 15 edges, thereby grid bus 15 part edges is not covered by the solid portion 19b of pixel electrode 19.Therefore, at (among the area L L of Figure 39 dotted line definition just) around grid bus 15 part edges that do not covered by solid portion 19b, by resulting near the tilting electric field bus 15 edges, light leak appears in inclination liquid crystal molecule 30a thus.

And owing to result near the tilting electric field in bus 18 edges, residual charge may appear among the opening 19a, 19a exposes insulating material by opening, if because the influence of residual charge is tilted along the liquid crystal molecule 30a among the opening 19a of bus 18 layouts, it will cause light leak.Though the residual charge degree relies on the surface appearance of insulating material and changes, when not excessive print register film or injection liquid crystal material, changing appears in the insulating material surface appearance.Therefore, in liquid crystal indicator, there is variation in the residual charge in the display plane.If residual charge changes in the display plane, the light leak degree also changes in the display plane, causes the contrast ratio localized variation thus, thereby produces heterogeneity.Especially, as mentioned above, because high relatively voltage is applied to grid bus 15, grid bus 15 promotes that obviously heterogeneity occurs.

As the diagram of Figure 39 institute, in liquid crystal indicator 800, pixel electrode 19 comprises opening 19a, form opening 19a and make it at grid bus 15 edges, thereby grid bus 15 part edges is not covered by the solid portion 19b of pixel electrode 19.Therefore, have a zone near grid bus 15 edges, this zone is not covered by the conducting film of pixel electrode 19 (solid portion 19b), therefore, because light leak appears in the residual charge in this zone, therefore causes showing heterogeneity.

On the contrary, in the liquid crystal indicator 500 of present embodiment, form the opening 19a of pixel electrode 19, make it not at grid bus 15 edges, and grid bus 15 edges are covered by the solid portion 19b of pixel electrode 19.Therefore, the liquid crystal molecule 30a of electric shield liquid crystal layer 30 makes it avoid resulting near the influence of the tilting electric field in bus 18 edges.Therefore the liquid crystal molecule 30a of liquid crystal layer 30 is not tilted the orientation adjusting power inclination of electric field.Therefore, suppressed the light leak generation, suppressed contrast ratio thus and reduce.And, in liquid crystal indicator 500, grid bus 15 edges are covered by the solid portion 19b of pixel electrode 19, and near the zone grid bus 15 edges is covered by the conducting film of pixel electrode 19 (solid portion 19b), residual charge can not occur thus, thereby has suppressed the heterogeneity generation.As mentioned above, in liquid crystal indicator 500, suppressed owing to be created in the light leak generation that near grid bus 15 tilting electric fields cause, suppressed the contrast ratio reduction thus, suppressed simultaneously to realize high-quality demonstration thus because the heterogeneity that near the residual charge the grid bus 15 causes takes place.

Note, though described present embodiment above about a certain situation, this situation is exactly that grid bus 15 edges are covered by the solid portion 19b of pixel electrode 19, but as selecting, may use a kind of arrangement, in the graphic liquid crystal indicator 500A of Figure 40, in this was arranged, source bus line 16 edges were covered by the solid portion 19b of pixel electrode 19.By with in solid portion 19b overlies gate bus 15 edges of pixel electrode 19 and source bus line 16 edges at least one, may improve display quality.Since usually be created in source bus line 16 edges near tilting electric field compare, be created near the tilting electric field in grid bus 15 edges liquid crystal molecule is had bigger influence, preferably, grid bus 15 edges are covered by the solid portion 19b of pixel electrode 19 at least.And in order to suppress to be created near the influence of the tilting electric field bus 18 edges more reliably, preferably, in the graphic liquid crystal indicator 500B of Figure 41, grid bus 15 edges and source bus line 16 edges are all covered by the solid portion 19b of pixel electrode 19.

Though described the present invention in a preferred embodiment, but can revise invention disclosed in many ways and it is contemplated that many above embodiment of set forth in detail and description that are different from, this it will be apparent to those skilled in the art that.Therefore, by appending claims, be intended to cover all modifications that falls in practicalness of the present invention and the scope.

Claims (8)

1, a kind of liquid crystal indicator, a plurality of pixel regions that comprise first substrate, second substrate, are arranged on the liquid crystal layer between first substrate and second substrate and are used to produce demonstration, wherein:

Described first substrate comprises in its side near liquid crystal layer, be used for each pixel electrode, an on-off element that is electrically connected to described pixel electrode and a bus of a plurality of pixel regions, described bus comprises grid bus and the source bus line that is electrically connected to described on-off element;

Described second substrate comprises via the described liquid crystal layer counter electrode relative with described pixel electrode;

Described pixel electrode comprises a plurality of openings and a solid portion;

In each of a plurality of pixel regions, when not having impressed voltage between pixel electrode and the counter electrode, liquid crystal layer is got perpendicular alignmnet, and the orientation by tilting electric field regulator solution crystal layer, each the marginal portion at a plurality of openings of pixel electrode when having impressed voltage between pixel electrode and counter electrode produces described tilting electric field; With

In each of this a plurality of pixel regions, cover one of at least in grid bus edge and the source bus line edge by the solid portion of pixel electrode.

2, liquid crystal indicator according to claim 1, wherein in each of this a plurality of pixel regions, the grid bus edge is covered by the solid portion of pixel electrode at least.

3, liquid crystal indicator according to claim 1, wherein:

The solid portion of pixel electrode comprises a plurality of units solid portion; And

In each of this a plurality of pixel regions, by the tilting electric field that produces in each edge part office of these a plurality of openings of pixel electrode in response to the voltage that between pixel electrode and counter electrode, applies, liquid crystal layer forms a plurality of liquid crystal territory in these a plurality of openings and solid portion, in this a plurality of liquid crystal territory each got the radial skew orientation, and the orientation of each of this a plurality of liquid crystal territory changes according to impressed voltage, produces thus to show.

4, liquid crystal indicator according to claim 2, wherein:

The solid portion of pixel electrode comprises a plurality of units solid portion; And

In each of this a plurality of pixel regions, by the tilting electric field that produces in each edge part office of these a plurality of openings of pixel electrode in response to the voltage that between pixel electrode and counter electrode, applies, liquid crystal layer forms a plurality of liquid crystal territory in these a plurality of openings and solid portion, in this a plurality of liquid crystal territory each got the radial skew orientation, and the orientation of each of this a plurality of liquid crystal territory changes according to impressed voltage, produces thus to show.

5, according to one of any described liquid crystal indicator of claim 1-4, wherein liquid crystal layer forms a part of liquid crystal territory, and the tilting electric field of this part liquid crystal territory when having impressed voltage between pixel electrode and counter electrode is along getting the radial skew orientation in the part solid portion of bus location.

6, a kind of liquid crystal indicator, a plurality of pixel regions that comprise first substrate, second substrate, are arranged on the liquid crystal layer between first substrate and second substrate and are used to produce demonstration, wherein:

Described first substrate comprises in its side near liquid crystal layer, be used for a plurality of pixel regions each pixel electrode, be electrically connected to an on-off element and the bus of pixel electrode, described bus comprises grid bus and the source bus line that is electrically connected to described on-off element;

Described second substrate comprises via the described liquid crystal layer counter electrode relative with described pixel electrode;

Described pixel electrode comprises a plurality of openings and a solid portion, and described solid portion comprises a plurality of units solid portion;

In each of this a plurality of pixel regions, when not having impressed voltage between pixel electrode and the counter electrode, liquid crystal layer is got perpendicular alignmnet, and tilting electric field by producing in each edge part office of these a plurality of openings of pixel electrode in response to the voltage that between pixel electrode and counter electrode, applies, liquid crystal layer forms a plurality of liquid crystal territory in these a plurality of openings and solid portion, in this a plurality of liquid crystal territory each got the radial skew orientation, and the orientation of each of this a plurality of liquid crystal territory changes according to impressed voltage, produces thus to show;

The solid portion of pixel electrode also comprises a plurality of parts that have respectively corresponding to the shape of the part of unit solid portion;

The a plurality of parts of this of solid portion are positioned near the periphery of pixel region; And

In grid bus edge and the source bus line edge at least one covered by near these a plurality of parts that are positioned at the pixel region periphery.

7, liquid crystal indicator according to claim 6, wherein the grid bus edge is covered by near these a plurality of parts that are positioned at the pixel region periphery at least.

8, according to claim 6 or 7 described liquid crystal indicators, at least one that wherein is arranged near the pixel region periphery these a plurality of parts has corresponding to half shape of the pact of unit solid portion.

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