KR100449844B1 - Liquid crystal display device - Google Patents

Abstract

The first substrate has a recovery electrode, a switching element, and a bus line formed in each of the recovery regions on the liquid crystal layer side, and the second substrate has an opposite electrode facing the recovery electrode. The recovery electrode has a plurality of openings and a solid part consisting of a plurality of unit solid parts, and in each of the recovery areas, the liquid crystal layer takes a vertical alignment state when no voltage is applied, and when the voltage is applied, By the inclined electric field generated at the edge portion of the opening, a plurality of liquid crystal domains each having a radial oblique alignment state are formed in the plurality of openings and the solid portion. In each of the recovery regions, at least one of the plurality of openings adjacent to the bus line and located between two adjacent unit solid portions of the plurality of unit solid portions overlaps with the bus line.

Description

Liquid crystal display {LIQUID CRYSTAL DISPLAY DEVICE}

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device having a wide viewing angle characteristic and performing high quality display.

In recent years, as a display apparatus used for the display of a personal computer or the display part of a portable information terminal apparatus, a thin lightweight liquid crystal display device is used. However, the conventional twisted nematic type (TN type) and the super twisted nematic type (STN type) liquid crystal display devices have a drawback that the viewing angle is narrow, and various techniques have been developed to solve the problem.

As a representative technique for improving the viewing angle characteristic of a TN type or STN type liquid crystal display device, there is a method of adding an optical compensation plate. As another method, there is a transverse electric field system in which an electric field in a horizontal direction with respect to the surface of the substrate is applied to the liquid crystal layer. The liquid crystal display device of this transverse electric field system is mass-produced in recent years, and attracts attention. As another technique, there is a deformation of vertical aligned phase (DAP) using a nematic liquid crystal material having negative dielectric anisotropy as the liquid crystal material and a vertical alignment film as the alignment film. This is one of voltage controlled birefringence (ECB) systems, and controls the transmittance using the birefringence of the liquid crystal molecules.

However, although the transverse electric field system is one of the effective methods as the wide viewing angle technique, there is a problem that stable production is difficult in the manufacturing process because the production margin is significantly narrower than that of the normal TN type. This is because the gap between the substrates and the shift in the transmission axis (polarization axis) direction of the polarizing plate with respect to the alignment axis of the liquid crystal molecules greatly affect the display brightness and contrast ratio, and in order to control them with high precision and to perform stable production More technology development is needed.

In addition, in order to perform uniform display without display unevenness in the DAP type liquid crystal display device, it is necessary to perform orientation control. As a method of orientation control, there exists a method of orientation processing by rubbing the surface of an orientation film. However, when the rubbing treatment is performed on the vertical alignment film, rubbing lines are likely to occur in the display image and are not suitable for mass production.

On the other hand, as a method of performing orientation control without performing a rubbing process, a method of generating an inclined electric field by forming a slit (opening) in an electrode and controlling the orientation direction of liquid crystal molecules by the inclined electric field is also devised (Example For example, see Japanese Patent Application Laid-Open Nos. 6-301036 and 2000-47217. However, as a result of the present inventor's examination, in the method disclosed in the above publication, since the alignment state of the region of the liquid crystal layer corresponding to the opening of the electrode is not defined, the continuity of the alignment of the liquid crystal molecules is not sufficient, resulting in stable alignment. As a result, it is difficult to obtain the state over the entire sweep, resulting in uneven display.

Accordingly, some of the inventors of the present application form a predetermined electrode structure composed of openings and solid portions on one side of the pair of electrodes facing each other with the liquid crystal layer together with the other, and the edge of the openings A method of forming a plurality of liquid crystal domains having radial oblique alignments in these openings and solid portions by a gradient electric field generated in the portions has been proposed (Japanese Patent Application No. 2000-244648).

However, the present inventors have found that the display quality may not be sufficiently improved only by forming the electrode structure as disclosed in the above application. This problem is caused by the generation of an electric field in the vicinity of the edge of the bus line (wiring group) that exhibits an orientation regulation force that does not match the orientation regulation force of the gradient electric field generated at the edge portion of the opening.

This invention is made | formed in order to solve the said problem, Comprising: It aims at providing the liquid crystal display device which has a wide viewing angle characteristic, and is high in display quality.

1 is a view schematically showing the structure of one recovery area of the liquid crystal display device 100 of the embodiment according to the present invention, in which FIG. 1A is a top view and FIG. 1B is along a line 1B-1B 'in FIG. 1A. Taken section.

FIG. 2 is a diagram showing a state in which a voltage is applied to the liquid crystal layer 30 of the liquid crystal display device 100. FIG. 2A is a diagram schematically showing a state in which an orientation has started to change (ON initial state). 2b is a diagram schematically showing a steady state.

3A to 3D are diagrams schematically showing the relationship between the electric field lines and the alignment of the liquid crystal molecules.

4A to 4C are diagrams schematically showing the alignment states of liquid crystal molecules seen in the substrate normal direction in the liquid crystal display device 100 of the embodiment according to the present invention.

5A to 5C are diagrams schematically showing examples of radial oblique alignment of liquid crystal molecules.

6A and 6B are top views schematically showing another recovery electrode used in the liquid crystal display device of the embodiment according to the present invention.

7A and 7B are top views schematically showing still another recovery electrode used in the liquid crystal display device of the embodiment according to the present invention.

8A and 8B are top views schematically showing still another recovery electrode used in the liquid crystal display device of the embodiment according to the present invention.

Fig. 9 is a top view schematically showing still another recovery electrode used in the liquid crystal display device of the embodiment according to the present invention.

10A and 10B are top views schematically showing still another recovery electrode used in the liquid crystal display device of the embodiment according to the present invention.

FIG. 11A is a diagram schematically showing a unit grid of the pattern shown in FIG. 1A, and FIG. 11B is a diagram schematically showing a unit grid of the pattern shown in FIG. 9, and FIG. 11C is a pitch p and a solid portion. Graph showing relationship with area ratio.

Fig. 12 is a top view schematically showing the structure of a recovery region of the liquid crystal display device 100 of the embodiment according to the present invention.

FIG. 13 is a top view schematically showing the structure of a recovery region of the liquid crystal display device 700 in which an opening adjacent to the bus line does not overlap with the bus line. FIG.

14A and 14B are diagrams schematically showing the orientation of liquid crystal molecules in the vicinity of an opening close to a gate bus line of the liquid crystal display device 700, wherein FIG. 14A is a top view and FIG. 14B is a sectional view.

15A is a cross-sectional view taken along the line 15A-15A 'in FIG. 13, and FIG. 15B is a cross-sectional view taken along the line 15B-15B' in FIG.

16A and 16B are diagrams schematically showing the orientation of liquid crystal molecules in the vicinity of an opening close to the gate bus line of the liquid crystal display device 100 of the embodiment according to the present invention, and FIG. 16A is a top view and FIG. 16b is a sectional view.

Fig. 17 is a top view schematically showing the structure of a recovery region of liquid crystal display device 100A of the embodiment according to the present invention.

18 is a top view schematically showing the structure of a recovery region of the liquid crystal display device 100B of the embodiment according to the present invention.

Fig. 19 is a top view schematically showing the structure of a recovery region of liquid crystal display device 100C of the embodiment according to the present invention.

20 is a top view schematically showing the structure of a recovery region of the liquid crystal display device 100D of the embodiment according to the present invention.

Fig. 21A is a top view schematically showing the structure of a recovery area of the liquid crystal display device 100E of the embodiment according to the present invention, and Fig. 21B is an enlarged view showing the vicinity of the gate bus line in Fig. 21A.

Fig. 22A is a top view schematically showing the structure of a recovery region of the liquid crystal display device 100F of the embodiment according to the present invention, and Fig. 22B is an enlarged view showing the vicinity of the gate bus line in Fig. 22A.

Fig. 23 is a top view schematically showing the structure of a recovery region of liquid crystal display device 100G of the embodiment according to the present invention.

Fig. 24A is a top view schematically showing the structure of a recovery area of the liquid crystal display device 100H of the embodiment according to the present invention, and Fig. 24B is an enlarged view showing the vicinity of the gate bus line in Fig. 24A.

Fig. 25A is a top view schematically showing the structure of a recovery region of the liquid crystal display device 100I of the embodiment according to the present invention, and Fig. 25B is an enlarged view showing the vicinity of the gate bus line in Fig. 25A.

FIG. 26 is a diagram schematically showing the structure of one recovery area of the liquid crystal display 200 of another embodiment according to the present invention. FIG. 26A is a top view and FIG. 26B is a line 26B-26B 'in FIG. 26A. Cross section taken along.

27A to 27D are schematic diagrams for explaining the relationship between the alignment of liquid crystal molecules 30a and the shape of a surface having vertical alignment.

FIG. 28 is a diagram illustrating a state in which a voltage is applied to the liquid crystal layer 30 of the liquid crystal display device 200. FIG. 28A schematically illustrates a state in which an orientation has started to change (ON initial state), and FIG. 28B. Is a diagram schematically showing a steady state.

29A to 29C are schematic cross-sectional views of liquid crystal display devices 200A, 200B, and 200C of another embodiment in which the arrangement relationship between the openings and the convex portions is different.

30 is a diagram schematically showing a cross-sectional structure of the liquid crystal display device 200, taken along the line 30A-30A 'in FIG. 26A.

FIG. 31 is a diagram schematically showing the structure of one recovery area of the liquid crystal display 200D of another embodiment according to the present invention, in which FIG. 31A is a top view and FIG. 31B is a line 31B-31B 'in FIG. 31A. Cross section taken along.

32 is a diagram schematically showing a cross-sectional structure of a single region of a liquid crystal display device 300 having a two-layer structure electrode, in which FIG. 32A is a diagram showing a voltage-free state, and FIG. FIG. 32C is a diagram showing a started state (ON initial state), and FIG. 32C is a diagram showing a normal state.

FIG. 33 is a diagram schematically showing the structure of one recovery area of the liquid crystal display device 400 having convex portions on the opposing substrate, in which FIG. 33A is a top view, and FIG. 33B is 33B-33B 'in FIG. 33A. Section taken along the line.

FIG. 34 is a diagram schematically showing a cross-sectional structure of one sweep region of the liquid crystal display device 400. FIG. 34A is a diagram showing a voltage-free state, and FIG. 34B is a state in which the orientation has started to change (ON initial state). 34C is a diagram showing a steady state.

Fig. 35 is a top view schematically showing the structure of one recovery region of another liquid crystal display device 400A including convex portions on an opposing substrate.

36 is a top view schematically showing the structure of one recovery region of another liquid crystal display device 400B including a convex portion on an opposing substrate.

FIG. 37 is a top view schematically showing the structure of one recovery region of another liquid crystal display device 400C including a convex portion on an opposing substrate. FIG.

FIG. 38 is a diagram schematically showing the structure of one recovery area of the liquid crystal display device 500 of another embodiment according to the present invention, where FIG. 38A is a top view and FIG. 38B is 38B-38B 'in FIG. 38A'. Section taken along the line.

Fig. 39 is a top view schematically showing a liquid crystal display device 800 in which a part of the edge of the gate bus line is not covered by the solid portion of the recovery electrode.

40 is a top view schematically showing the structure of one recovery area of the liquid crystal display device 500A of still another embodiment according to the present invention.

Fig. 41 is a top view schematically showing the structure of one recovery area of the liquid crystal display device 500B of another embodiment according to the present invention.

<Explanation of symbols for the main parts of the drawings>

11: transparent substrate

14: recovery electrode

14a: opening

14b: solid part

22: facing substrate

30: liquid crystal layer

30a: liquid crystal molecules

The liquid crystal display device of the present invention includes a first substrate, a second substrate, and a liquid crystal layer formed between the first substrate and the second substrate, and has a plurality of recovery regions for displaying the display. The first substrate includes, on the liquid crystal layer side, a recovery electrode formed for each of the plurality of recovery regions, a switching element electrically connected to the recovery electrode, a gate bus line and a source bus line electrically connected to the switching element. A bus line, The said 2nd board | substrate has the counter electrode which opposes the said recovery electrode via the said liquid crystal layer, The said recovery electrode has the solid part which consists of a some opening part and a some unit solid part, In each of the recovery regions, the liquid crystal layer takes a vertical alignment state when a voltage is applied between the recovery electrode and the counter electrode, and further includes the recovery electrode. When a voltage is applied between the counter electrodes, the plurality of openings and the solid portions each have a radial oblique alignment state by a gradient electric field generated at edge portions of the plurality of openings of the recovery electrode. A liquid crystal display device which forms a liquid crystal domain and performs display by changing an alignment state of the plurality of liquid crystal domains according to an applied voltage, wherein each of the plurality of recovery regions includes the bus among the plurality of openings of the recovery electrode. At least one of the openings adjacent to the line and located between two unit solid portions adjacent to the plurality of unit solid portions has a configuration overlapping with the bus line, whereby the object is achieved.

Alternatively, the liquid crystal display device according to the present invention includes a first substrate, a second substrate, and a liquid crystal layer formed between the first substrate and the second substrate, and has a plurality of recovery regions for displaying. The first substrate includes, on the liquid crystal layer side, a recovery electrode formed for each of the plurality of recovery regions, a switching element electrically connected to the recovery electrode, a gate bus line and a source bus line electrically connected to the switching element. The second substrate has a counter electrode facing the recovery electrode via the liquid crystal layer, and the recovery electrode includes a plurality of openings, each of at least some of the plurality of openings. It has a solid part which consists of a some unit solid part surrounded by the opening part, The said liquid crystal layer has a vertical orientation when the voltage is applied between the said return electrode and the said counter electrode. A liquid crystal display device having a state, wherein each of the plurality of recovery regions is positioned between two unit solid portions adjacent to the bus line among the plurality of openings of the recovery electrode and adjacent to the plurality of unit solid portions. At least one of the openings has a configuration overlapping the bus line, whereby the object is achieved.

It is preferable that the at least one opening overlapping with the bus line includes at least an opening close to the gate bus line.

It is good also as a structure which all the openings which adjoin the said gate bus line among the said some opening part of the said recovery electrode overlap with the said bus line.

The at least one opening overlapping the bus line may further include an opening close to the source bus line.

It is preferable that the opening part of at least one part of the said some opening part has the structure which forms substantially the same size, and the at least 1 unit grid arrange | positioned so as to have rotation symmetry.

It is preferable that each shape of the said at least one part opening part of the said some opening part has rotational symmetry.

Each of the at least part of the openings of the plurality of openings may have a substantially circular configuration.

Each of the plurality of unit solid portions may have a substantially circular configuration.

In each of the plurality of recovery areas, the sum of the areas of the plurality of openings of the recovery electrode is preferably configured to be smaller than the area of the solid part of the recovery electrode.

A convex portion is further provided inside each of the plurality of openings, and the cross-sectional shape in the in-plane direction of the substrate of the convex portion is the same as that of the plurality of openings, and the side surfaces of the convex portions are liquid crystal molecules of the liquid crystal layer. It may be configured so as to have an orientation regulating force in the same direction as the orientation regulating direction by the inclined electric field.

Another liquid crystal display device according to the present invention includes a first substrate, a second substrate, and a liquid crystal layer formed between the first substrate and the second substrate, and has a plurality of recovery regions for displaying, The first substrate includes a recovery electrode formed for each of the plurality of recovery regions, a switching element electrically connected to the recovery electrode, a gate bus line and a source bus line electrically connected to the switching element. And a bus line including the counter electrode, wherein the second substrate has an opposite electrode facing the recovery electrode via the liquid crystal layer, and the recovery electrode has a plurality of openings and a solid portion, respectively, in each of the plurality of recovery regions. And the liquid crystal layer takes a vertical alignment state when a voltage is applied between the recovery electrode and the counter electrode, and between the recovery electrode and the counter electrode. A liquid crystal display device whose orientation is regulated by a gradient electric field generated at edge portions of the plurality of openings of the recovery electrode when voltage is applied, wherein each of the plurality of recovery regions includes one of the gate bus line and the source bus line. At least one edge has the structure covered by the said solid part of the said recovery electrode, and the said objective is achieved by this.

In each of the plurality of recovery regions, at least an edge of the gate bus line is preferably covered by the solid portion of the recovery electrode.

Further, in each of the plurality of recovery regions, the edges of both the gate bus line and the source bus line may be covered by the solid portion of the recovery electrode.

The solid part of the recovery electrode includes a plurality of unit solid parts, and in each of the plurality of recovery areas, the liquid crystal layer is the plurality of the recovery electrodes when a voltage is applied between the recovery electrode and the counter electrode. A plurality of liquid crystal domains, each of which has a radial inclination alignment state, are formed in the plurality of openings and the solid portion by an inclined electric field generated at the edge portion of the opening of the openings of the plurality of liquid crystal domains. It is good also as a structure which displays by changing an orientation state.

In each of the plurality of recovery regions, at least one of the openings adjacent to the bus line and located between two unit solid portions adjacent to the plurality of unit solid portions among the plurality of openings of the recovery electrode, It is good also as a structure which overlaps with a bus line.

The liquid crystal layer forms a portion of the liquid crystal domain in which a radial oblique alignment state is formed in the solid portion proximate to the bus line by the gradient electric field when a voltage is applied between the recovery electrode and the counter electrode. It is good also as a structure.

The operation will be described below.

In the liquid crystal display device of the present invention, a recovery electrode for applying a voltage to the liquid crystal layer in the recovery region includes a plurality of openings (parts in which no conductive film exists in the electrode) and solid parts (parts other than the openings in the electrode and the conductive film). Existing part). The solid portion has a plurality of unit solid portions, each of which is substantially surrounded by an opening, and is typically formed of a continuous conductive film. The liquid crystal layer takes a vertical alignment state in a voltage-free state, and in the voltage application state, a plurality of liquid crystal domains taking a radial oblique alignment state are formed by a gradient electric field generated at the edge portion of the opening of the recovery electrode. Typically, the liquid crystal layer is made of a liquid crystal material having negative dielectric anisotropy, and is oriented by a vertical alignment film formed on both sides thereof.

The liquid crystal domain formed by this inclined electric field is formed in the area | region corresponding to the opening part and solid part of a recovery electrode, and displays by making the orientation state of these liquid crystal domains change with voltage. Since each liquid crystal domain takes an axial symmetry orientation, the visual dependence of display quality is small, and it has a wide visual characteristic.

In addition, since the liquid crystal domain formed in the opening portion and the liquid crystal domain formed in the solid portion are formed by the inclined electric field generated in the edge portion of the opening portion, they are alternately formed adjacent to each other, and the liquid crystal between adjacent liquid crystal domains. The orientation of the molecules is essentially continuous. Therefore, no disclination line is generated between the liquid crystal domain formed in the opening portion and the liquid crystal domain formed in the solid portion, and there is no deterioration in display quality due to this. Therefore, the stability of alignment of liquid crystal molecules is also high.

In the liquid crystal display device of the present invention, since the liquid crystal molecules take a radial oblique alignment not only in the region corresponding to the solid portion of the recovery electrode, but also in the region corresponding to the opening portion, the liquid crystal molecules are compared The continuity of orientation is high, the stable orientation state is implement | achieved, and the uniform display without display unevenness is obtained. In particular, in order to realize good response characteristics (fast response speed), it is necessary to make a gradient electric field for controlling the alignment of liquid crystal molecules act on many liquid crystal molecules, and therefore, it is necessary to form many openings (edge portions). have. In the liquid crystal display of the present invention, since a liquid crystal domain having a stable radial oblique alignment is formed corresponding to the opening, even if a large number of openings are formed in order to improve response characteristics, deterioration of display quality accompanying them (generation of display unevenness) Can be suppressed.

However, only by forming the above-described electrode structure, the display quality may not be sufficiently improved depending on the relative positional relationship between the opening of the recovery electrode and the edge of the bus line (wiring group).

Since a predetermined signal (voltage) for driving the liquid crystal display device is applied to the bus line of the liquid crystal display device, an electric field is generated between the bus line and the counter electrode. Therefore, the gradient electric field is generated near the edge of the bus line, but the orientation regulating force by the gradient electric field is not matched with the orientation regulating force by the gradient electric field generated at the edge portion of the opening. Therefore, when the liquid crystal domain formed in the opening adjacent to the bus line is subjected to the alignment control force by the inclined electric field near the edge of the bus line, the orientation is disturbed, resulting in a distorted radial oblique alignment state. In addition, since adjacent liquid crystal domains intend to maintain the continuity of orientation with each other, the disturbance of the above-mentioned orientation affects the orientation of the adjacent liquid crystal domain, ie, the liquid crystal domain of the adjacent unit solid part, and the adjacent unit The orientation of the liquid crystal domain of the solid portion is also disturbed.

The alignment is disturbed, and the liquid crystal domain having a distorted radial oblique alignment is liable to collapse because of low stability of the alignment, and takes a long time until the alignment reaches a steady state when voltage is applied. Therefore, the disturbance of the orientation as described above causes a decrease in response speed (degradation of response characteristics).

In addition, the liquid crystal domain formed in the recovery area is brought to a steady state in the distorted and distorted radial oblique alignment state as described above. However, since this state is different for each recovery area, the previous image is input when a signal for switching the image is input. This remaining afterimage phenomenon may occur. It is because the transmittance | permeability also differs between recovery areas when the orientation state of a liquid crystal layer differs between recovery areas. In particular, in the recovery region changed from the white display state to the halftone display state and the recovery region changed from the black display state to the halftone display state, the difference in the alignment state of the liquid crystal layer is remarkable, and the difference in transmittance is regarded as an afterimage phenomenon. It is easily recognized. In the back display state, since the inclination electric field generated at the edge portion of the opening exhibits a relatively strong orientation control force, the alignment of the liquid crystal layer is stable. Therefore, the alignment of the liquid crystal layer is stable even in the halftone display state. On the other hand, when the halftone display state is changed from the black display state, since the alignment regulating force due to the inclined electric field generated at the edge portion of the opening is relatively weak, the alignment of the liquid crystal layer is likely to collapse.

In the liquid crystal display device according to the present invention, in each of the plurality of recovery regions, at least one of the openings located between the two unit solid portions adjacent to the bus line among the plurality of openings of the recovery electrode is located at the bus line. Since it is comprised so that it may overlap (a part of bus line strictly), the edge of the bus line near the opening part which overlaps with a bus line is covered by the unit solid part of a recovery electrode.

Therefore, in the vicinity of the opening overlapping with the bus line, the influence of the gradient electric field generated near the edge of the bus line is electrically shielded (shielded) by the unit solid part of the recovery electrode, so that the liquid crystal molecules of the liquid crystal layer The orientation is regulated only by the gradient electric field generated at the edge portion of the opening portion without receiving the orientation control force due to the gradient electric field generated near the edge of the line. Therefore, in the liquid crystal display device which concerns on this invention, the orientation of the opening part which overlaps a bus line, and the liquid crystal domain formed in the unit solid part adjacent to it is not disturbed, As a result, the response speed falls (deterioration of response characteristic). The occurrence of afterimage phenomenon is suppressed.

From the viewpoint of suppressing the disturbance of the orientation due to the gradient electric field generated near the edge of the bus line, the ratio of the openings overlapping with the bus line is increased, that is, most of the edges of the bus line at the unit solid portion of the recovery electrode. Although it is preferable to coat | cover, the fall of the aperture ratio by making this ratio high may become a problem when a bus line is formed with the light-shielding material. What is necessary is just to set the ratio of the opening part which overlaps with a bus line in accordance with the use of a liquid crystal display device, etc. in consideration of desired response characteristic and aperture ratio.

A structure in which an opening overlapping with a bus line and positioned between two adjacent unit solid parts includes an opening close to at least a gate bus line (of the openings adjacent to the bus line and located between two adjacent unit solid parts By adopting a structure in which at least an opening close to the gate bus line overlaps with the bus line), it is possible to effectively suppress a decrease in response speed and generation of an afterimage phenomenon. This is because a larger voltage is generally applied to the gate bus line than the source bus line, so that the gradient electric field generated near the edge of the gate bus line is more liquid crystal molecules than the gradient electric field generated near the edge of the source bus line. Because it has a big impact on.

In addition, not only the opening located between two adjacent unit solid portions, the other opening adjacent to the bus line may be configured to overlap the bus line. For example, you may comprise so that the whole opening part adjacent to a gate bus line may overlap with a bus line among the some opening part of a recovery electrode.

Of course, you may employ | adopt the structure which the opening part located between two adjacent unit solid parts and the opening part which overlaps with a bus line includes the opening part which adjoins a source bus line.

Incidentally, the gradient electric field generated near the edge of the bus line not only causes the above-mentioned response speed and the afterimage phenomenon, but also causes the contrast ratio, but the bus line is formed of a material having light shielding properties. If it exists, the fall of contrast ratio is suppressed as demonstrated below.

As described above, a gradient electric field is generated near the edge of the bus line, but the gradient electric field is generated regardless of the presence or absence of an applied voltage to the liquid crystal layer between the recovery electrode and the counter electrode. Therefore, in the liquid crystal display device which performs normal black mode display, when a voltage is not applied, when liquid crystal molecules on the edge of a bus line incline under the orientation control force by this gradient electric field, light leakage will arise and contrast ratio will fall. It may become. In particular, since a relatively large voltage is usually applied to the gate bus line to turn off the switching element, occurrence of this light leakage is prominent near the edge of the gate bus line.

In the liquid crystal display device according to the present invention, the edge of the bus line near the opening overlapping with the bus line is covered by the unit solid portion of the recovery electrode, and the influence of the gradient electric field generated near the edge of the bus line is electrically Since it is shielded (shielded), the liquid crystal molecules of the liquid crystal layer are not inclined under the orientation control force due to the two-inclined electric field. Although the liquid crystal molecules in the liquid crystal layer in the opening overlapping with the bus line may be inclined by an electric field generated between the bus line and the counter electrode, when the bus line is formed of a light-shielding material, the opening overlapping with the bus line is Shading. Therefore, in the liquid crystal display device according to the present invention, when the bus line is formed of a light shielding material, the occurrence of light leakage is suppressed and the decrease in contrast ratio is suppressed.

In addition, if the bus line is formed of a material having light shielding properties, generation of unevenness (local variation of contrast ratio) in the display surface is suppressed as described below, and the display quality is improved.

When the insulator material is peeled off by an inclined electric field generated near the edge of the bus line, residual potential tends to occur, and when liquid crystal molecules in the opening close to the bus line are inclined under the influence of the residual potential, Cause. The extent to which this residual potential remains depends on the surface state of the insulator material, but fluctuations occur in the surface state of the insulator material at the time of printing the alignment film or injecting the liquid crystal material. Therefore, in the liquid crystal display device, there is a variation in the residual potential in the display surface. When the residual potential is changed in the display surface, it is varied in the display surface by the light leakage, so that local variation in the contrast ratio occurs, causing unevenness. In particular, since a relatively large voltage is applied to the gate bus line as described above, the gate bus line greatly contributes to the occurrence of the above-mentioned spots.

In the liquid crystal display device according to the present invention, when the bus line is formed of a material having light shielding properties, since the opening overlapping with the bus line is shielded by the bus line, occurrence of unevenness as described above is suppressed, and display quality Is improved.

At least a part of the plurality of openings has a configuration in which at least one unit grid has substantially the same shape in the same shape and is arranged to have rotational symmetry, thereby forming a plurality of liquid crystal domains based on the unit grid. Since it can arrange | position with high symmetry, the visual dependence of display quality can be improved. In addition, by dividing the entire recovery area into a unit cell, the orientation of the liquid crystal layer can be stabilized over the entire recovery area. For example, the openings are arranged such that the center of each opening forms a square lattice. In addition, when one recovery area is divided by an opaque component such as a storage capacitor wiring, a unit grid may be arranged for each area contributing to the display.

Stability of the radial oblique alignment of the liquid crystal domains formed in the openings can be enhanced by making the shapes of the openings (typically the openings forming the unit lattice) of at least some of the plurality of openings have shapes having rotational symmetry. For example, the shape of each opening part (shape when viewed from the substrate normal direction) is circular or regular polygonal (for example, square). The shape (aspect ratio) of the pixel may be used as the shape (eg, ellipse) having no rotational symmetry. Further, the region of the solid portion substantially enclosed in the opening, that is, the shape of the unit solid portion has rotational symmetry, thereby improving the stability of the radial oblique alignment of the liquid crystal domain formed in the solid portion. For example, when arrange | positioning an opening part in a square grid | lattice shape, you may make the shape of an opening part substantially star shape, a cross shape, etc., and the solid part shape may be made into the shape of a substantially circular shape, a substantially square shape, etc. Of course, the shape of the opening portion and the solid portion substantially surrounded by the opening portion may be substantially square.

In order to stabilize the radial oblique alignment of the liquid crystal domain formed in the opening of the electrode, the liquid crystal domain formed in the opening is preferably approximately circular. In other words, the shape of the opening may be designed so that the liquid crystal domain formed in the opening becomes substantially circular.

Of course, in order to stabilize the radial oblique alignment of the liquid crystal domain formed in the solid portion of the electrode, the region of the solid portion substantially surrounded by the opening is preferably circular. Any one liquid crystal domain formed in the solid portion formed of the continuous conductive film is formed corresponding to the region (unit solid portion) of the solid portion substantially surrounded by the plurality of openings. Therefore, what is necessary is just to determine the shape of the opening part and its arrangement | positioning so that the shape of the area | region (unit solid part) of this solid part may become substantially circular.

In any of the above cases, it is preferable that the sum of the areas of the openings formed in the electrodes is smaller than the area of the solid part in each of the recovery areas. The larger the area of the solid part is, the larger the area of the liquid crystal layer (as defined in the plane when viewed in the direction of the substrate normal line) that is directly affected by the electric field generated by the electrode, thus the optical characteristics of the voltage of the liquid crystal layer (eg For example, transmittance) is improved.

It is preferable to determine by which structure the area of a solid part can be enlarged whether the structure which an opening part adopts substantially circular shape or the unit solid part employ | adopts the structure which becomes substantially circular shape is adopted. Which configuration is preferable is appropriately selected depending on the pitch of the sweep. Typically, when the pitch exceeds about 25 mu m, it is preferable to form an opening so that the solid portion becomes substantially circular, and when it is about 25 mu m or less, it is preferable to make the opening substantially circular.

Since the alignment control force by the gradient electric field generated at the edge portion of the opening formed in the above-described electrode acts only when voltage is applied, it is applied to the liquid crystal panel, for example, when no voltage is applied or when a relatively low voltage is applied. When an external force is applied, radial oblique alignment of the liquid crystal domain may not be maintained. In order to solve this problem, in the liquid crystal display device of any embodiment of the present invention, a convex portion having a side surface having an alignment regulating force in the same direction as the orientation regulating direction by the inclined electric field described above with respect to the liquid crystal molecules of the liquid crystal layer is electrode. On the inside of the opening. The cross-sectional shape of the board | substrate of this convex part in the in-plane direction is the same as that of the opening part, and it is preferable to have rotation symmetry similarly to the shape of the opening part mentioned above.

The liquid crystal display device according to the present invention can realize stable radial inclination orientation only by forming an opening in the collecting electrode and making the edge of the opening electrode and the edge of the bus line have a predetermined positional relationship. That is, in the known manufacturing method, when the conductive film is patterned in the shape of the recovery electrode, the photomask is modified so that the opening of the desired shape is formed in the desired arrangement, and the bus line is in the desired shape when the bus line is patterned. The liquid crystal display device according to the present invention can be manufactured by only modifying the photomask to be formed.

In another liquid crystal display device according to the present invention, at least one edge of the gate bus line and the source bus line is covered by the solid portion of the recovery electrode. Therefore, in the vicinity of the bus line where the edge is covered by the solid part of the recovery electrode, since the influence of the gradient electric field generated near the edge of the bus line is electrically shielded (shielded), the liquid crystal layer is subjected to the alignment control force by the gradient electric field. The liquid crystal molecules are not tilted. Therefore, generation | occurrence | production of light leakage is suppressed and the fall of contrast ratio is suppressed. Moreover, since the area | region near the edge covered with the solid part of a recovery electrode is covered with the conductive film (solid part) of a recovery electrode, a residual electric potential hardly arises and generation | occurrence | production of a stain is suppressed. As described above, in the other liquid crystal display device according to the present invention, the occurrence of light leakage due to the inclined electric field generated near the bus line is suppressed and the decrease in the contrast ratio is suppressed, as well as the residual potential near the bus line. Since generation | occurrence | production of the stain | dye resulting from this is also suppressed, high quality display is implement | achieved.

Since the gradient electric field generated near the edge of the gate bus line has a greater influence on the liquid crystal molecules than the gradient electric field generated near the edge of the source bus line, at least the edge of the gate bus line should be covered by the solid part of the recovery electrode. desirable. In addition, from the viewpoint of more reliably suppressing the influence of the gradient electric field generated near the edge of the bus line, it is preferable to cover the edges of both the gate bus line and the source bus line with the solid part of the recovery electrode.

In the liquid crystal display device according to the present invention, the deterioration of display quality due to the inclined electric field generated near the edge of the bus line is suppressed. Therefore, according to the present invention, a liquid crystal display device having a wide viewing angle characteristic and high display quality is provided.

This invention is used suitably for the active-matrix type liquid crystal display device, and is suitably used also for all the liquid crystal display devices of a transmission type, a reflection type, and a transmission reflection combined use type.

<Example>

EMBODIMENT OF THE INVENTION Hereinafter, the Example of this invention is described, referring drawings.

First, the electrode structure of the liquid crystal display device of this invention and its effect are demonstrated. Hereinafter, an embodiment of the present invention will be described with respect to an active matrix liquid crystal display device using a thin film transistor (TFT). In addition, below, although the Example of this invention is described using a transmissive liquid crystal display device as an example, this invention is not limited to this, It can also be applied to a reflection type liquid crystal display device and a transmissive reflection combined type liquid crystal display device.

In addition, in this specification, the area | region of the liquid crystal display device corresponding to "recovery" which is the minimum unit of display is called "recovery area | region." In a color liquid crystal display device, "recovery" of R, G, and B corresponds to one "pixel". In the active matrix liquid crystal display device, the recovery electrode and the counter electrode facing the recovery electrode define the recovery region. In the configuration in which the black matrix is formed, strictly, the region corresponding to the opening of the black matrix corresponds to the recovery region among the regions where the voltage is applied according to the state to be displayed.

1A and 1B, the structure of one recovery area of the liquid crystal display device 100 of the embodiment according to the present invention will be described. In the following, the color filter and the black matrix are omitted for simplicity of explanation. In addition, in the following drawings, the component which has the function substantially the same as the component of the liquid crystal display device 100 is shown with the same code | symbol, and the description is abbreviate | omitted. FIG. 1A is a top view seen from the substrate normal direction, and FIG. 1B corresponds to a sectional view taken along the line 1B-1B 'in FIG. 1A. 1B illustrates a state in which no voltage is applied to the liquid crystal layer.

The liquid crystal display device 100 includes an active matrix substrate (hereinafter referred to as a "TFT substrate") 100a, an opposing substrate (also referred to as a "color filter substrate") 100b, a TFT substrate 100a and an opposing substrate ( It has the liquid crystal layer 30 formed between 100b). The liquid crystal molecules 30a of the liquid crystal layer 30 have negative dielectric anisotropy and are vertical alignment films as vertical alignment layers formed on the surfaces of the liquid crystal layer 30 side of the TFT substrate 100a and the opposing substrate 100b (not shown). When the voltage is not applied to the liquid crystal layer 30, it is orientated perpendicularly to the surface of the vertical alignment film as shown in FIG. 1B. At this time, the liquid crystal layer 30 is said to be in a vertical alignment state. However, the liquid crystal molecules 30a of the liquid crystal layer 30 in the vertical alignment state may be slightly inclined from the normal of the surface (the surface of the substrate) of the vertical alignment film depending on the type of the vertical alignment film or the kind of the liquid crystal material. . Generally, the state in which the liquid crystal molecular axis (also referred to as "axial orientation") is oriented at an angle of about 85 ° or more with respect to the surface of the vertical alignment film is called a vertical alignment state.

The TFT substrate 100a of the liquid crystal display device 100 has a transparent substrate (for example, a glass substrate) 11 and a recovery electrode 14 formed on the surface thereof. The opposing board | substrate 100b has the transparent board | substrate (for example, glass substrate) 21, and the opposing electrode 22 formed in the surface. According to the voltage applied to the recovery electrode 14 and the counter electrode 22 which are disposed to face each other via the liquid crystal layer 30, the alignment state of the liquid crystal layer 30 for each recovery region is changed. With the change of the orientation state of the liquid crystal layer 30, display is performed using the phenomenon in which the polarization state or quantity of the light which permeate | transmits the liquid crystal layer 30 changes.

The recovery electrode 14 which the liquid crystal display device 100 has has the some opening part 14a and the solid part 14b. The opening portion 14a indicates a portion where the conductive film in the recovery electrode 14 formed of a conductive film (for example, an ITO film) has been removed, and the solid portion 14b has a portion other than the opening portion 14a (the opening portion 14a). Part). A plurality of openings 14a are formed for each of the recovery electrodes, but the solid portions 14b are basically formed of a single continuous conductive film.

The plurality of openings 14a are disposed so that their centers form a square lattice, and are substantially solid surrounded by four openings 14a whose centers are located on four lattice points forming one unit lattice. The part (called "unit solid part") 14b 'has a substantially circular shape. Each of the openings 14a has four quarter arc-shaped sides (edges), and is a substantially star shape having four rotation axes at its center. Here, in order to stabilize the orientation over the entire recovery region, a unit cell is formed to the end of the recovery electrode 14. That is, as shown in the drawing, the end of the recovery electrode 14 is approximately one-half (region corresponding to the side) of the opening 14a located at the center of the recovery electrode 14 and about one quarter ( Patterned into a shape corresponding to an angle), and the opening portion 14a is also disposed at the end of the recovery electrode 14.

The openings 14a located at the center of the recovery area have the same size in substantially the same shape. The unit solid portions 14b 'positioned in the unit grid formed by the openings 14a are substantially circular and have the same size in substantially the same shape. The unit solid portions 14b 'adjacent to each other are connected to each other, and constitute a solid portion 14b that functions substantially as a single conductive film.

When a voltage is applied between the recovery electrode 14 and the counter electrode 22 having the above-described configuration, a plurality of liquid crystals each having a radial oblique alignment by a gradient electric field generated at the edge portion of the opening 14a. Domains are formed. One liquid crystal domain is formed in the area | region corresponding to each opening part 14a, and the area | region corresponding to the unit solid part 14b 'in a unit grating, respectively.

Although the square recovery electrode 14 is illustrated here, the shape of the recovery electrode 14 is not limited to this. Since the general shape of the recovery electrode 14 is approximated by a rectangle (including square and rectangle), the openings 14a can be arranged regularly in a square lattice shape. Even if the recovery electrode 14 has a shape other than a spherical shape, the openings 14a are regularly arranged (for example, in a square lattice shape as illustrated) so that the liquid crystal domains are formed in all regions in the recovery area. The effect of the invention can be obtained.

The mechanism by which the liquid crystal domain is formed by the above-described gradient electric field will be described with reference to FIGS. 2A and 2B. 2A and 2B show a state where a voltage is applied to the liquid crystal layer 30 shown in FIG. 1B, respectively, and FIG. 2A shows liquid crystal molecules 30a according to the voltage applied to the liquid crystal layer 30. FIG. 2B schematically shows a state in which the orientation of the liquid crystal molecules 30a changed in accordance with the applied voltage has reached a steady state. have. The curve EQ in FIGS. 2A and 2B represents equipotential line EQ.

When the recovery electrode 14 and the counter electrode 22 are at the same potential (no voltage is applied to the liquid crystal layer 30), as shown in FIG. 1A, the liquid crystal molecules 30a in the recovery region And perpendicular to the surfaces of both substrates 11 and 21.

When a voltage is applied to the liquid crystal layer 30, a potential gradient represented by the equipotential line EQ (orthogonal to the electric field line) shown in Fig. 2A is formed. This equipotential line EQ is applied to the surfaces of the solid portion 14b and the counter electrode 22 in the liquid crystal layer 30 positioned between the solid portion 14b and the counter electrode 22 of the recovery electrode 14. On the EG parallel and falling in the area corresponding to the opening 14a of the recovery electrode 14, the edge of the opening 14a (the inner periphery of the opening 14a including the boundary (outer edge) of the opening 14a) In the liquid crystal layer 30, a gradient electric field represented by an inclined equipotential line EQ is formed.

A torque for aligning the axial orientation of the liquid crystal molecules 30a in parallel (vertical to the electric field lines) with respect to the equipotential lines EQ acts on the liquid crystal molecules 30a having negative dielectric anisotropy. Accordingly, the liquid crystal molecules 30a on the edge portion EG are inclined (rotated) in the clockwise direction in the right edge portion EG of the figure and counterclockwise in the left edge portion EG of the figure, as indicated by the arrows in FIG. 2A. And parallel to the equipotential line EQ.

Here, with reference to FIG. 3, the change of the orientation of the liquid crystal molecule 30a is demonstrated in detail.

When an electric field is generated in the liquid crystal layer 30, a torque is applied to the liquid crystal molecules 30a having negative dielectric anisotropy in order to align their axial directions in parallel to the equipotential line EQ. As shown in FIG. 3A, when an electric field represented by an equipotential line EQ perpendicular to the axial orientation of the liquid crystal molecules 30a occurs, the liquid crystal molecules 30a have the same probability of inclining clockwise or counterclockwise. Acts as. Therefore, in the liquid crystal layer 30 between the electrodes of the parallel plate-type arrangement | positioning which oppose each other, the liquid crystal molecule 30a which receives a clockwise torque and the liquid crystal molecule 30a which receives a counterclockwise torque are mixed. As a result, the change to the alignment state according to the voltage applied to the liquid crystal layer 30 may not occur smoothly.

As shown in Fig. 2A, in the edge portion EG of the opening portion 14a of the liquid crystal display device 100 according to the present invention, an electric field (inclination) indicated by an equipotential line EQ inclined with respect to the axial orientation of the liquid crystal molecules 30a. 3b, the liquid crystal molecules 30a incline in a direction (anticlockwise direction in the illustrated example) with a small amount of inclination for parallel with the equipotential line EQ. Further, as shown in FIG. 3C, the liquid crystal molecules 30a positioned in the region where the electric field represented by the equipotential line EQ in the vertical direction with respect to the axial orientation of the liquid crystal molecules 30a are inclined. It is inclined in the same direction as the liquid crystal molecules 30a positioned on the inclined equipotential line EQ so that the alignment with the liquid crystal molecules 30a positioned in the (continuously) is aligned. As shown in FIG. 3D, when an electric field in which the equipotential line EQ forms a continuous concave-convex shape is applied, it is matched with the orientation direction regulated by the liquid crystal molecules 30a positioned on each inclined equipotential line EQ. The liquid crystal molecules 30a positioned on the flat equipotential line EQ are oriented. In addition, "located on the equipotential line EQ" means "located in the electric field represented by equipotential line EQ".

As described above, when the orientation change starting from the liquid crystal molecules 30a positioned on the inclined equipotential line EQ progresses and reaches a steady state, the orientation state schematically illustrated in FIG. 2B is obtained. Since the liquid crystal molecules 30a located near the center of the opening portion 14a are almost equally affected by the orientation of the liquid crystal molecules 30a of the edge portions EG on both sides of the opening portion 14a facing each other, the equipotential line EQ The liquid crystal molecules 30a in the region away from the center of the opening portion 14a are inclined under the influence of the alignment of the liquid crystal molecules 30a of the edge portion EG near each other, while maintaining the alignment state perpendicular to the opening portion 14a. A symmetrical oblique orientation is formed with respect to the center SA of 14a. In this alignment state, when viewed in a direction perpendicular to the display surface of the liquid crystal display device 100 (in a direction perpendicular to the surfaces of the substrates 11 and 21), the axial orientation of the liquid crystal molecules 30a is the center of the opening 14a. It is in the state oriented radially with respect to (not shown). Therefore, in this specification, such an orientation state is called "radial oblique orientation." In addition, the area | region of the liquid crystal layer which has radial oblique orientation with respect to one center is called liquid crystal domain.

Even in a region corresponding to the unit solid portion 14b 'substantially surrounded by the opening 14a, a liquid crystal domain in which the liquid crystal molecules 30a have a radial oblique alignment is formed. The liquid crystal molecules 30a in the region corresponding to the unit solid portion 14b 'are affected by the orientation of the liquid crystal molecules 30a of the edge portion EG of the opening 14a, and thus the center SA of the unit solid portion 14b' is affected. Radial oblique orientation is symmetrical with respect to (corresponding to the center of the unit lattice formed by the opening 14a).

The radial oblique alignment in the liquid crystal domain formed in the unit solid portion 14b 'and the radial oblique alignment formed in the opening 14a are continuous, and both the alignments of the liquid crystal molecules 30a of the edge portion EG of the opening 14a are continuous. It is oriented to match with. The liquid crystal molecules 30a in the liquid crystal domain formed in the opening 14a are oriented in the shape of an open cone on the upper side (the substrate 100b side), and the liquid crystal molecules 30a in the liquid crystal domain formed in the unit solid portion 14b ' The lower side (substrate 100a side) is oriented in the open cone shape. As described above, since the radial inclination orientations formed in the liquid crystal domain formed in the opening 14a and the liquid crystal domain formed in the unit solid portion 14b 'are continuous with each other, a disclination line is formed at these boundaries. Lines (orientation defects) are not formed, whereby deterioration of display quality due to generation of disclination lines does not occur.

In order to improve the visual dependence of the display quality of the liquid crystal display device in all orientations, it is preferable that the existence probability of liquid crystal molecules oriented along each of all azimuthal directions within each combustion region has rotational symmetry, and axial symmetry It is more preferable to have. That is, it is preferable that the liquid crystal domain formed over the whole recovery area is arranged to have rotational symmetry or axial symmetry. However, it is not necessary to necessarily have rotational symmetry throughout the recovery region, but is a collection region as an aggregate of liquid crystal domains (for example, a plurality of liquid crystal domains arranged in a square lattice) arranged to have rotational symmetry (or axial symmetry). The liquid crystal layer of may be formed. Accordingly, the arrangement of the plurality of openings 14a formed in the recovery area does not necessarily have to have rotational symmetry throughout the recovery area, but is arranged to have rotational symmetry (or axial symmetry) (for example, arranged in a square lattice shape). What is necessary is just to represent it as an aggregate of the several some opening part. Of course, the same also applies to the arrangement of the unit solid portions 14b 'substantially surrounded by the plurality of openings 14a. In addition, since the shape of each liquid crystal domain preferably has not only rotational symmetry but also axial symmetry, it is preferable that the shape of each opening 14a and unit solid part 14b 'also has not only rotational symmetry but also axial symmetry. .

Moreover, sufficient voltage is not applied to the liquid crystal layer 30 near the center of the opening part 14a, and the liquid crystal layer 30 near the center of the opening part 14a may not contribute to display. That is, even if the radial inclination orientation of the liquid crystal layer 30 near the center of the opening portion 14a is slightly disturbed (for example, even if the central axis is out of the center of the opening portion 14a), the display quality does not decrease. have. Therefore, what is necessary is just to arrange | position so that the liquid crystal domain formed corresponding at least to the unit solid part 14b 'may have rotational symmetry and axial symmetry.

As described with reference to FIGS. 2A and 2B, the recovery electrode 14 of the liquid crystal display device 100 according to the present invention has a plurality of openings 14a and is inclined in the liquid crystal layer 30 in the recovery region. Form an electric field represented by an equipotential line EQ with one area. The liquid crystal molecules 30a having negative dielectric anisotropy in the liquid crystal layer 30 in the vertical alignment state when no voltage is applied are aligned by triggering the change in the alignment of the liquid crystal molecules 30a positioned on the inclined equipotential line EQ. By changing the direction, a liquid crystal domain having a stable radial oblique alignment is formed in the opening portion 14a and the solid portion 14b. In accordance with the voltage applied to the liquid crystal layer, the orientation of the liquid crystal molecules in this liquid crystal domain is changed, thereby displaying.

The shape (shape seen from the board | substrate normal line direction) of the cleaning electrode 14 of the liquid crystal display device 100 of this embodiment, and its arrangement are demonstrated.

The display characteristic of a liquid crystal display device shows azimuth dependence due to the orientation state (optical anisotropy) of liquid crystal molecules. In order to reduce the azimuth dependence of display characteristics, it is preferable that the liquid crystal molecules are aligned with equal probability with respect to all azimuth angles. Moreover, it is more preferable that the liquid crystal molecules in each recovery area are oriented with equal probability with respect to all azimuth angles. Therefore, it is preferable that the opening part 14a has the shape which forms a liquid crystal domain so that the liquid crystal molecules 30a in each recovery area may be oriented with equal probability with respect to all azimuth angles. Specifically, the shape of the opening portion 14a preferably has rotational symmetry (preferably symmetry of two or more rotation axes) with each center (normal direction) as the symmetry axis, and the plurality of openings 14a It is preferable to arrange | position so as to have rotational symmetry. Moreover, it is preferable that the shape of the unit solid part 14b 'substantially surrounded by these opening parts also has rotational symmetry, and it is preferable that the unit solid part 14b' is also arrange | positioned so that it may have rotational symmetry.

However, the opening portion 14a or the unit solid portion 14b 'need not necessarily be disposed so as to have rotational symmetry over the entire recovery area. As shown in Fig. 1A, for example, a square lattice (with four rotation axes) is provided. Symmetry) as a minimum unit, and combinations thereof constitute a recovery region, the liquid crystal molecules can be oriented with substantially equal probability for all azimuth angles throughout the recovery region.

4A to 4B illustrate the alignment states of the liquid crystal molecules 30a when the substantially star-shaped openings 14a and the substantially circular unit solid portions 14b 'having the rotational symmetry shown in FIG. 1A are arranged in a square lattice shape. It demonstrates, referring 4c.

4A to 4C schematically show the alignment states of the liquid crystal molecules 30a as viewed from the substrate normal line direction, respectively. In the figure which shows the orientation state of the liquid crystal molecule 30a seen from the board | substrate normal line direction, such as FIG. 4B and FIG. 4C, the stage in which the edge of the liquid crystal molecule 30a drawn in ellipse shape is displayed in black is more than the other end. The liquid crystal molecules 30a are inclined so as to be close to the substrate side on which the recovery electrode 14 having the openings 14a is formed. The same applies to the following drawings. Here, one unit grating (formed by four openings 14a) in the recovery area shown in FIG. 1A will be described. Sections along the diagonal lines in Figs. 4A to 4C correspond to Figs. 1B, 2A and 2B, respectively, and are described with reference to all of these drawings.

When the recovery electrode 14 and the counter electrode 22 are at the same potential, that is, in a state where no voltage is applied to the liquid crystal layer 30, the liquid crystal layer 30 of the TFT substrate 100a and the counter substrate 100b. As shown in FIG. 4A, the liquid crystal molecules 30a whose orientation direction is regulated by the vertical alignment layer (not shown) formed on the side surface take a vertical alignment state.

When an electric field is applied to the liquid crystal layer 30 to generate an electric field represented by the equipotential line EQ shown in FIG. 2A, the axial orientation becomes parallel to the equipotential line EQ in the liquid crystal molecules 30a having negative dielectric anisotropy. Torque is generated. As described with reference to FIGS. 3A and 3B, the liquid crystal molecules 30a under an electric field represented by an equipotential line EQ perpendicular to the molecular axis of the liquid crystal molecules 30a are inclined (rotated) by the liquid crystal molecules 30a. Since the direction is not uniquely defined (FIG. 3A), the change of the orientation (tilt or rotation) does not easily occur, whereas the liquid crystal molecules placed under the equipotential EQ inclined with respect to the molecular axis of the liquid crystal molecules 30a. In 30a, since the inclination (rotation) direction is uniquely determined, a change in orientation occurs easily. Therefore, as shown in FIG. 4B, the liquid crystal molecules 30a start to incline from the edge portion of the opening portion 14a where the molecular axis of the liquid crystal molecules 30a is inclined with respect to the equipotential line EQ. As described with reference to FIG. 3C, the surrounding liquid crystal molecules 30a are also inclined such that the alignment and the alignment of the inclined liquid crystal molecules 30a of the edge portion of the opening 14a are inclined, as shown in FIG. 4C. In the state, the axial orientation of the liquid crystal molecules 30a is stabilized (radial oblique alignment).

Thus, if the opening part 14a is a shape which has rotational symmetry, the liquid crystal molecule 30a in a recovery area | region will be a liquid crystal molecule 30a toward the center of the opening part 14a from the edge part of the opening part 14a at the time of voltage application. ) Is inclined, the liquid crystal molecules 30a near the center of the opening 14a where the alignment regulating force of the liquid crystal molecules 30a from the edges are balanced remain in a state of being vertically aligned with respect to the substrate surface. The state in which the liquid crystal molecules 30a of the liquid crystal molecules 30a are continuously inclined radially about the liquid crystal molecules 30a near the center of the opening 14a is obtained.

In addition, the liquid crystal molecules 30a in the region corresponding to the substantially circular unit solid portions 14b 'surrounded by the four substantially star-shaped openings 14a arranged in a square lattice shape also have edge portions at the edges of the openings 14a. Inclined to match the orientation of the liquid crystal molecules 30a inclined by the generated oblique electric field. The liquid crystal molecules 30a near the center of the unit solid portion 14b 'where the alignment regulating force of the liquid crystal molecules 30a from the edge portion is balanced remain in a state of being vertically aligned with respect to the substrate surface, and the liquid crystal molecules around them. A state in which the liquid crystal molecules 30a are continuously inclined in a radial shape with respect to the liquid crystal molecules 30a near the center of the unit solid portion 14b 'is obtained.

As described above, when the liquid crystal domains in which the liquid crystal molecules 30a have a radial oblique alignment are arranged in a square lattice shape, the existence probability of the liquid crystal molecules 30a in each axial direction becomes rotationally symmetrical throughout the region. High quality display without spots can be realized in all visual directions. In order to reduce the visual dependence of the liquid crystal domain having a radial oblique alignment, it is preferable that the liquid crystal domain has a high rotational symmetry (preferably at least two rotation axes, more preferably at least four rotation axes). Moreover, in order to reduce the visual dependence of the whole recovery area | region, the some liquid crystal domain formed in the recovery area | region has the unit which has high rotational symmetry (preferably two rotation axes or more, and four rotation axes or more more preferable) (Example For example, it is preferable to construct an array (for example, a square grating) represented by a combination of unit gratings.

Further, the radial inclination orientation of the liquid crystal molecules 30a is a spiral inclination of spiral shape turning to the left or to the right as shown in FIGS. 5B and 5C, rather than a simple radial inclination orientation as shown in FIG. 5A. The orientation is stable. As for this spiral-shaped orientation, the orientation direction of the liquid crystal molecules 30a does not change in a spiral shape along the thickness direction of the liquid crystal layer 30 as in the normal twist orientation, and the orientation direction of the liquid crystal molecules 30a is in a minute region. As a result, there is little change along the thickness direction of the liquid crystal layer 30. That is, even in the end surface (cross section in surface parallel to a layer surface) of the position in the thickness direction of the liquid crystal layer 30, in the same orientation as FIG. 5B or FIG. 5C, the twist along the thickness direction of the liquid crystal layer 30 is performed. Almost no deformation occurs. However, in the whole liquid crystal domain, the twist distortion generate | occur | produces to some extent.

If a material in which chiral agent is added to a nematic liquid crystal material having negative dielectric anisotropy is used, the liquid crystal molecules 30a are centered around the opening 14a and the unit solid portion 14b 'at the time of voltage application. The radial oblique orientation of the spiral shape turning to the left or to the right, as shown in FIGS. 5B and 5C, is taken. Whether it is a right rotation direction or a left rotation direction is determined by the kind of chiral agent to be used. Therefore, by spirally aligning the liquid crystal layer 30 in the opening 14a at the time of voltage application, the circumference of the liquid crystal molecules 30a of the liquid crystal molecules 30a which are inclined radially is perpendicular to the substrate surface. Since the direction of winding can be made constant in all the liquid crystal domains, uniform display without spots becomes possible. Moreover, since the direction which winds the periphery of the liquid crystal molecule 30a standing perpendicular to a board | substrate surface is determined, the response speed at the time of applying a voltage to the liquid crystal layer 30 also improves.

When the chiral agent is added, the orientation of the liquid crystal molecules 30a is changed into a spiral shape along the thickness direction of the liquid crystal layer 30 as in the usual twist orientation. In the alignment state in which the orientation of the liquid crystal molecules 30a does not change in a spiral shape along the thickness direction of the liquid crystal layer 30, the liquid crystal molecules 30a oriented in the vertical direction or parallel direction with respect to the polarization axis of the polarizing plate are incident light. Since no phase difference is given with respect to the incident light passing through the region in this alignment state, it does not contribute to the transmittance. On the other hand, in the orientation state in which the orientation of the liquid crystal molecules 30a changes in a helical shape along the thickness direction of the liquid crystal layer 30, the liquid crystal molecules 30a that are aligned in a direction perpendicular to or parallel to the polarization axis of the polarizing plate, In addition to giving a phase difference with respect to incident light, it is also possible to use the linearity of light. Therefore, since the incident light which passes through the area | region in such an orientation state contributes to the transmittance | permeability, the liquid crystal display device which can display bright display can be obtained.

In FIG. 1A, although the opening 14a has a substantially star shape, and the unit solid portion 14b 'has a substantially circular shape and they are arranged in a square lattice shape, the opening 14a and the unit solid portion 14b' are illustrated. ) And their arrangement are not limited to the above examples.

6A and 6B show top views of the recovery electrodes 14A and 14B having openings 14a and unit solid portions 14b 'of different shapes, respectively.

The openings 14a and the unit solid portions 14b 'of the recovery electrodes 14A and 14B shown in FIGS. 6A and 6B, respectively, are the openings 14a and the unit solid portions 14b' of the recovery electrodes shown in FIG. 1A. ) Has a slightly distorted shape. The openings 14a and the unit solid portions 14b 'of the storage electrodes 14A and 14B have two rotation axes (not having four rotation axes) and are regularly arranged to form a rectangular unit cell. The openings 14a all have a distorted star shape, and the unit solid portions 14b 'all have a substantially elliptical shape (distorted circle). Even if the cleaning electrodes 14A and 14B are used, a liquid crystal display device having high display quality and excellent in visual characteristics can be obtained.

In addition, the recovery electrodes 14C and 14D as shown in Figs. 7A and 7B may be used.

In the pixel electrodes 14C and 14D, the cross-shaped openings 14a are arranged in a square lattice shape so that the unit solid portions 14b 'are substantially square. Of course, you may distort and arrange | position so that a rectangular unit cell may be formed. Thus, even if the unit solid part 14b 'of substantially spherical shape (a spherical shape includes a square and a rectangle) is regularly arranged, a liquid crystal display device with high display quality and excellent visual characteristics can be obtained.

However, the shape of the opening portion 14a and / or the unit solid portion 14b 'is preferable because the circular or elliptical side can stabilize the radial inclination orientation than the spherical shape. This is considered to be because the side of the opening portion 14a changes continuously (smoothly), so that the alignment direction of the liquid crystal molecules 30a also changes continuously (smoothly).

In view of the continuity of the alignment direction of the liquid crystal molecules 30a described above, the recovery electrodes 14E and 14F shown in FIGS. 8A and 8B are also conceivable. The recovery electrode 14E shown in FIG. 8A is a modification of the recovery electrode 14 shown in FIG. 1A, and has an opening 14a composed of only four circular arcs. 8B is a modification of the recovery electrode 14D shown in FIG. 7B, and the unit solid portion 14b 'side of the opening 14a is formed by an arc. The openings 14a and the unit solid portions 14b 'of the electrodes 14E and 14F all have four rotational axes, and are arranged in a square lattice shape (having four rotational axes). As shown in Fig. 6B, the unit solid portion 14b 'of the opening 14a is distorted to have a shape having two rotational axes, and arranged so as to form a rectangular lattice (with two rotational axes). do.

In the above-described example, the openings 14a of the substantially star shape or the cross shape are formed, and the shape of the unit solid portion 14b 'is made into a substantially round shape, approximately elliptical shape, approximately square shape (spherical shape) and rounded approximately spherical shape. The configuration has been described. In contrast, the relationship between the opening portion 14a and the unit solid portion 14b 'may be negative-positive inverted. For example, FIG. 9 shows a recovery electrode 14G having a pattern in which the opening 14a and the unit solid portion 14b of the recovery electrode 14 shown in FIG. 1A are negative-positive inverted. In this manner, the recovery electrode 14G having the negative-positive inverted pattern also has substantially the same function as the recovery electrode 14 shown in FIG. 1. In addition, in the case where both the opening portion 14a and the unit solid portion 14b 'are substantially square, as in the recovery electrodes 14H and 14I shown in FIGS. 10A and 10B, respectively, even if the negative-positive inversion is performed, the original pattern In some cases, the pattern may be the same as.

Like the pattern shown in FIG. 9, even when the pattern shown in FIG. 1A is negative-positive inverted, the opening portion is formed such that the unit solid portion 14b ′ having rotational symmetry is formed at the edge portion of the recovery electrode 14. It is preferable to form part (about one half or about one quarter) of (14a). By setting it as such a pattern, in the edge part of a recovery area | region, similarly to the center part of a recovery area | region, the effect by a gradient electric field is acquired and stable radial inclination orientation can be achieved over the whole recovery area | region.

Next, the recovery electrode shown in FIG. 9 having a pattern in which the pattern of the recovery electrode 14 of FIG. 1A, the opening 14a of the recovery electrode 14, and the unit solid part 14b ′ is negative-positive inverted ( Taking 14G) as an example, which of the negative-positive patterns is adopted will be described.

Even if any pattern of negative-positive is adopted, the length of the side of the opening part 14a is the same in both patterns. Therefore, in the function of generating the gradient electric field, there is no difference due to these patterns. However, the area ratio of the unit solid portion 14b '(ratio to the total area of the recovery electrode 14) may be different between them. That is, the area of the solid portion 14b (actually the portion where the conductive film is present) that generates the electric field employed in the liquid crystal molecules of the liquid crystal layer may be different.

Since the voltage applied to the liquid crystal domain formed in the opening portion 14a is lower than the voltage applied to the liquid crystal domain formed in the solid portion 14b, for example, when the display in the normal black mode is displayed, the opening 14a is applied to the opening 14a. The liquid crystal domain formed darkens. That is, when the area ratio of the opening part 14a becomes high, it will become the tendency for display brightness to fall. Therefore, it is preferable that the area ratio of the solid part 14b is higher.

It depends on the pitch (size) of the unit grating in which the area ratio of the solid part 14b becomes high in either the pattern of FIG. 1A or the pattern of FIG.

FIG. 11A shows the unit grid of the pattern shown in FIG. 1A, and FIG. 11B shows the unit grid of the pattern shown in FIG. 9 (but centering on the opening 14a). In addition, in FIG. 11B, the part (branch part extended in all directions from a circular part) of the unit solid part 14b 'in FIG. 9 which serves to connect with each other is abbreviate | omitted. The length (pitch) of one side of a square unit grating is set to p, and the length (space on one side) of the clearance gap between the opening part 14a or the unit solid part 14b 'and a unit grating is set to s.

Various recovery electrodes 14 having different values of pitch p and one-sided space s were formed, and the stability of radial oblique orientation and the like were examined. As a result, first, in order to generate the inclination electric field required for obtaining the radial inclination orientation by using the recovery electrode 14 having the pattern shown in FIG. 11A (hereinafter referred to as "positive pattern"), one-sided space s Was found to be about 2.75 μm or greater. On the other hand, with respect to the recovery electrode 14 having the pattern shown in FIG. 11B (hereinafter referred to as "negative pattern"), the one-side space s is about 2.25 µm or more in order to generate an inclined electric field for obtaining a radial inclination orientation. I found it necessary. The area ratio of the solid part 14b at the time of changing the value of pitch p was made into the lower limit value of each side space s, respectively. The results are shown in Table 1 and FIG. 11C.

Pitch P (μm) Solid area ratio (%) Positive type (a) Negative (b) 20 41.3 52.9 25 47.8 47.2 30 52.4 43.3 35 55.8 40.4 40 58.4 38.2 45 60.5 36.4 50 62.2 35.0

As can be seen from Table 1 and FIG. 11C, when the pitch p is about 25 µm or more, the area ratio of the solid portion 14b is higher in the positive pattern (FIG. 11A), and becomes shorter when it is shorter than about 25 µm (FIG. 11A). 11b), the area ratio of the solid part 14b becomes large. Therefore, from the viewpoint of display luminance and stability of orientation, the pattern to be employed is changed with the pitch p at about 25 μm. For example, when three or less unit gratings are formed in the width direction of the recovery electrode 14 having a width of 75 µm, the positive pattern shown in FIG. 11A is preferable, and four or more unit gratings are formed. In this case, the negative pattern shown in Fig. 11B is preferable. Also in a case other than the illustrated pattern, either positive type or negative type may be selected so that the area ratio of the solid portion 14b is increased.

The number of unit grids is obtained as follows. With respect to the width (horizontal or vertical) of the storage electrode 14, the size of the unit grid is calculated so that one or two or more integer unit grids are arranged, and the solid area ratio is calculated for each unit grid size. The unit grid size at which the solid area ratio is maximized is selected. However, in the case of a positive pattern, when the diameter of the unit solid portion 14b 'is less than 15 µm, and in the case of a negative pattern, the diameter of the opening 14a is less than 15 µm, the orientation regulating force due to the gradient electric field decreases. It is difficult to obtain stable radial oblique orientation. In addition, the lower limit of these diameters is a case where the thickness of the liquid crystal layer 30 is about 3 micrometers, and when the thickness of the liquid crystal layer 30 is thinner than this, the diameter of the unit solid part 14b 'and the opening part 14a will be A stable radial oblique orientation is obtained even if it is smaller than the above lower limit, and the diameter of the unit solid portion 14b 'and the opening portion 14a, which are necessary for obtaining a stable radial oblique orientation when the thickness of the liquid crystal layer 30 is thicker than this, are obtained. The lower limit of the value becomes larger than the lower limit described above.

In addition, as will be described later, by forming the convex portion inside the opening 14a, the stability of the radial inclination orientation can be improved. The above-mentioned conditions are all about the case where no convex part is formed.

As described above, the display of the wide viewing angle is realized by forming the electrode structure expressing the alignment regulating force for forming the liquid crystal domain having the radial oblique alignment state in the recovery region.

However, only by forming the electrode structure as described above, the relative positional relationship between the opening 14a of the recovery electrode 14 and the edge (edge) of the bus line (wiring group) formed in the TFT substrate 100a is determined. Therefore, the inventors of the present application have found that the display quality may not be sufficiently improved. In the liquid crystal display device 100 according to the present invention, the opening 14a of the recovery electrode 14 and the edge of the bus line have a positional relationship described later, whereby high quality display is realized.

Here, with reference to FIG. 12, the positional relationship of the opening part 14a of the recovery electrode 14 and the edge of the bus line 18 in the liquid crystal display device 100 of this embodiment is demonstrated. 12 is a top view schematically showing the recovery region of the liquid crystal display device 100 of the present embodiment. In the following drawings, the TFTs formed for each of the recovery regions in the TFT substrate 100a are omitted.

As shown in FIG. 12, the TFT substrate 100a of the liquid crystal display device 100 is electrically connected to the recovery electrode 14 formed for each recovery region and the recovery electrode 14 on the liquid crystal layer 30 side. And a bus line 18 including a gate bus line (scan wiring) 15 and a source bus line (signal wiring) 16 electrically connected to the TFT as a switching element. . In this embodiment, the bus line 18 further has a storage capacitor wiring 17 for forming the storage capacitor.

In this embodiment, as shown in FIG. 12, in each of the recovery regions, some of the openings 14a of the openings 14a adjacent to the bus lines 18 overlap the bus lines 18. More specifically, of the openings 14a that are close to the bus line 18, the openings 14a that are close to the gate bus line 15 and located between two adjacent unit solid portions 14b 'are provided. It overlaps with the bus line 18 (gate bus line 15). That is, when viewed from the TFT substrate 100a side, the gate bus line 15 is configured to cover the openings 14a between the adjacent unit solid portions 14b ', and viewed from the opposing substrate 100b side. The unit solid portion 14b ′ sandwiching the opening 14a is configured to cover the edge of the gate bus line 15. Here, the gate bus line 15 is formed to have a branch portion protruding toward the opening portion 14a between the adjacent unit solid portions 14b ', whereby the opening portion between the adjacent unit solid portions 14b' is formed. 14a and the gate bus line 15 overlap each other.

In the liquid crystal display device 100, as described above, some of the openings 14a of the openings 14a proximate the bus lines 18 overlap the bus lines 18, whereby high-quality display is performed. Is realized. This reason will be described with reference to FIGS. 13, 14 and 16 in comparison with the case where the opening 14a adjacent to the bus line 18 does not overlap with the bus line 18.

FIG. 13: is a top view which shows typically the liquid crystal display device 700 in which the opening part 14a which adjoins the bus line 18 does not overlap with the bus line 18. FIG. 14A and 14B are diagrams schematically showing the orientation of liquid crystal molecules 30a near the opening 14a near the gate bus line 15 of the liquid crystal display device 700, and FIG. 14A. Is a top view, and FIG. 14B is a sectional view taken along the line 14B-14B 'in FIG. 14A. 16A and 16B are diagrams schematically showing the orientation of liquid crystal molecules 30a near the opening 14a near the gate bus line 15 of the liquid crystal display device 100 of the present embodiment. 16A is a top view and FIG. 16B is a sectional view taken along line 16B-16B 'in FIG. 16A.

When driving the liquid crystal display device, since a predetermined signal (voltage) for driving the liquid crystal display device is applied to the bus line 18 formed on the TFT substrate 100a, the bus line 18 and the counter electrode ( Between 22) an electric field is generated. Therefore, although the inclination electric field is generated in the vicinity of the edge of the bus line 18, the orientation control force by this inclination electric field does not match with the orientation control force by the inclination electric field produced | generated in the edge part of the opening part 14a. Therefore, when the liquid crystal domain formed in the opening part 14a which adjoins the bus line 18 receives the orientation control force by the inclined electric field near the edge of the bus line 18, the orientation will be distorted, and it will be in the distorted radial oblique alignment state. do.

For example, in the liquid crystal display device 700 in which the opening 14a adjacent to the bus line 18 as shown in FIG. 13 does not overlap with the bus line 18, the gate bus line 15 is connected to the gate bus line 15. Note the orientation of the liquid crystal molecules 30a near the adjacent openings 14a. At the time of voltage application, as shown in FIG. 14B, the liquid crystal molecules 30a of the edge portions of the openings 14a are formed of the openings 14a. While the liquid crystal molecules 30a near the edge of the gate bus line 15 are inclined in the left rotational direction (counterclockwise) due to the inclined electric field formed on the edge portion, the liquid crystal molecules 30a near the edge of the gate bus line 15. The inclined electric field is inclined in the right rotational direction (clockwise). Therefore, the liquid crystal layer 30 in the opening part 14a forms the liquid crystal domain of the distorted radial oblique alignment state (here, pressed and crushed) as shown in FIG. 14A.

Since adjacent liquid crystal domains are intended to maintain the continuity of orientation with each other, as described above, when the alignment of the liquid crystal domain of the opening portion 14a adjacent to the bus line 18 is disturbed, the disturbance of the alignment is adjacent to the liquid crystal domain. The orientation of the liquid crystal domain, that is, the liquid crystal domain formed in the unit solid portion 14b ', is also affected, and the alignment of the liquid crystal domain of the unit solid portion 14b' is also disturbed.

The orientation is disturbed, and the liquid crystal domain having the distorted radial oblique alignment is liable to collapse because of low stability of the orientation, and the time until the orientation reaches a steady state at the time of voltage application is long. Therefore, the disturbance of the orientation as described above causes a decrease in response speed (degradation of response characteristics).

In addition, the liquid crystal layer 30 in each of the recovery regions is brought into a steady state in the radial oblique alignment state in which the orientation is disturbed and distorted as described above. However, since this state is different for each of the recovery regions, when the signal for switching the image is inputted, The afterimage phenomenon in which an image remains is sometimes generated. This is because if the alignment state of the liquid crystal layer 30 is different between the recovery regions, the transmittance is also different between the recovery regions. In particular, in the recovery region changed from the white display state to the halftone display state and the recovery region changed from the black display state to the halftone display state, the difference in the alignment state of the liquid crystal layer 30 is remarkable, so that the difference in transmittance is It is easy to recognize it as an afterimage phenomenon. In the back display state, since the inclination electric field generated at the edge portion of the opening portion 14a exerts a relatively strong orientation control force, the alignment of the liquid crystal layer 30 is stable, and therefore, in the halftone display state. Even when the alignment of the liquid crystal layer 30 is stable, in the case of making the halftone display state from the black display state, since the alignment control force due to the inclined electric field generated at the edge portion of the opening portion 14a is relatively weak, The orientation of the liquid crystal layer 30 tends to collapse.

In contrast, in the liquid crystal display device 100 according to the present invention, as shown in FIG. 12, an opening part 14a of a part of the opening part 14a proximate the bus line 18, specifically, a gate bus line. Since the opening part 14a which is adjacent to 15 and located between two adjacent unit solid parts 14b 'is comprised so that it may overlap with the bus line 18 (gate bus line 15), The edge of the bus line 18 near the opening 14a overlapping with the bus line 18 is covered by the unit solid portion 14b 'of the recovery electrode 14.

Therefore, in the vicinity of the opening 14a overlapping with the bus line 18, the influence of the gradient electric field generated near the edge of the bus line 18 is caused by the unit solid portion 14b ′ of the recovery electrode 14. Since the liquid crystal molecules 30a are shielded (shielded), the liquid crystal molecules 30a of the liquid crystal layer 30 do not receive the alignment control force by the gradient electric field generated near the edges of the bus lines 18, and thus the edge portions of the openings 14a are not exposed. The orientation is regulated only by the generated gradient electric field.

Therefore, in the liquid crystal display device 100 which concerns on this invention, the orientation of the liquid crystal domain formed in the opening part 14a which overlaps with the bus line 18, and the unit solid part 14b 'adjacent to it is not disturbed, As a result, a decrease in response speed (deterioration of response characteristics) and generation of afterimage phenomenon are suppressed, and high quality display is realized.

Incidentally, the gradient electric field generated near the edge of the bus line 18 causes not only the above-mentioned drop in the response speed and the afterimage phenomenon, but also a decrease in the contrast ratio. If it is formed using a material having a structure, a decrease in the contrast ratio is suppressed. It will be described in more detail below.

As described above, a gradient electric field is generated near the edge of the bus line 18, but the gradient electric field is correlated with the presence or absence of an applied voltage to the liquid crystal layer 30 between the recovery electrode 14 and the counter electrode 22. Is generated without Therefore, in the liquid crystal display device which displays the display in normal black mode, when the voltage is not applied, if the liquid crystal molecules 30a on the edge of the bus line 18 are inclined under the orientation regulating force by this inclined electric field, light leakage may occur. It may generate | occur | produce and a contrast ratio may fall. In particular, since the relatively large voltage (off voltage) for turning off the TFT is applied to the gate bus line 15 in most cases, the occurrence of this light leakage in the vicinity of the edge of the gate bus line 15 Remarkable

In the liquid crystal display device 100 of this embodiment, the edge of the bus line 18 near the opening 14a overlapping the bus line 18 is covered by the unit solid portion 14b 'of the recovery electrode 14. Since the influence of the gradient electric field generated near the edge of the bus line 18 is electrically shielded (shielded), the liquid crystal molecules 30a of the liquid crystal layer 30 are inclined under the orientation control force by the gradient electric field. There is no case. Although the liquid crystal molecules 30a of the liquid crystal layer 30 in the opening 14a overlapping with the bus line 18 may be inclined by an electric field generated between the bus line 18 and the counter electrode 22, If the bus line 18 is formed of a light shielding material, the opening overlapping with the bus line 18 is shielded.

Therefore, when the bus line 18 is formed of a material having light shielding properties, a decrease in contrast ratio due to light leakage at the time of black display is suppressed, and display of higher quality is realized.

In addition, when the bus line 18 is formed of a material having light shielding properties, generation of unevenness (local variation in contrast ratio) in the display surface is suppressed as described below, and the display quality is improved. .

Due to the inclined electric field generated near the edge of the bus line 18, residual potential tends to occur in the opening portion 14a where the insulator material is peeled off, and the liquid crystal molecules in the opening portion 14a adjacent to the bus line 18 ( If 30a) is inclined under the influence of the residual potential, it causes light leakage. The extent to which this residual potential remains depends on the surface state of the insulator material. However, the surface state of the insulator material causes variations in the printing of the alignment film and the injection of the liquid crystal material. Therefore, in the liquid crystal display device, there is a variation in the residual potential in the display surface. When the residual potential varies within the display surface, the degree of light leakage varies within the display surface, so that local variations in the contrast ratio occur, causing unevenness. In particular, since a relatively large voltage is applied to the gate bus line 15 as described above, the gate bus line 15 contributes greatly to the generation of the above-mentioned spots.

In the liquid crystal display device 100 according to the present invention, if the bus line 18 is formed of a material having light shielding properties, the opening 14a overlapping the bus line 18 is blocked by the bus line 18. For this reason, occurrence of unevenness as described above is suppressed, and display quality is improved.

In the liquid crystal display 700 shown in FIG. 13, as shown in FIG. 15A (corresponding to a cross-sectional view taken along the line 15A-15A 'in FIG. 13) near the edge of the gate bus line 15. As shown in FIG. 15B (corresponding to a cross-sectional view taken along the line 15B-15B 'in FIG. 13), the recovery electrode (the region where the conductive film (solid portion 14b) is not formed) is used. The area | region in which the conductive film of 14) was formed is mixed. Therefore, in the region where the conductive film (solid part 14b) is not formed near the edge of the gate bus line 15, as shown in FIG. 15A, an electric field caused by the gate bus line 15 is caused by an electric field. Impurity ions are adsorbed on the surface of the TFT substrate 100a, and the orientation of the adsorbed impurities (hereinafter, referred to as "accumulated charges") is generated. Therefore, even if the bus line 18 is formed of a light-shielding material, in the opening portion (region LL enclosed by the broken line in FIG. 13) near the gate bus line 15, the disturbance of the orientation due to the accumulated charge is prevented. And light leakage occurs.

In contrast, in the liquid crystal display device 100 according to the present invention, a region strongly affected by the electric field due to the gate bus line 15, that is, the region shown in FIG. 15B near the edge of the gate bus line 15. Similarly, since there are many regions in which the conductive film (solid portion 14b) of the recovery electrode 14 is formed, occurrence of disturbance in orientation due to accumulated charge is suppressed and light leakage is suppressed.

In addition, impurities which cause accumulation charges are not uniformly distributed in the display surface, and are typically present locally in the form of stripes in the display surface. This is because when the liquid crystal material is injected from a plurality of injection holes arranged at predetermined intervals, impurities are concentrated in the region between the injection holes where the flow velocity is slowed.

Therefore, in the region where the impurities are present locally (regions with a large amount of impurities) and other regions (regions with a small amount of impurities), the extent of formation or leakage of accumulated charges is different. The degree of light leakage will be different in the area different from the area. As a result, in the liquid crystal display device 700 shown in FIG. 13, the stripe-shaped region is a "black stripe" having a higher luminance than the other regions, or a "white stripe" having a lower luminance than the other regions. Cause.

On the other hand, in the liquid crystal display device 100 which concerns on this invention, since generation | occurrence | production of the light leakage by the accumulation charge is suppressed as mentioned above, generation | occurrence | production of a display unevenness is also suppressed.

Here, in each of the recovery regions, among the openings 14a close to the bus line 18, the openings 14a close to the gate bus line 15 and located between the unit solid portions 14b 'are provided. Although the case where it overlaps with the bus line 18 was demonstrated, this invention is not limited to this. In each of the recovery regions, by adopting a configuration in which some of the openings 14a of the openings 14a which are close to the bus lines 18 and located between the unit solid portions 14b 'overlap the bus lines 18. The disturbance of the orientation of the liquid crystal domain is suppressed, whereby a decrease in response speed (deterioration of response characteristics) and generation of afterimage phenomenon are suppressed.

From the viewpoint of suppressing the disturbance of the orientation due to the inclined electric field generated near the edge of the bus line 18, the ratio of the opening 14a overlapping with the bus line 18 is increased, that is, the recovery electrode 14 It is preferable to cover most of the edges of the bus lines 18 with the unit solid portions 14b '. In the case where the bus line 18 is formed of a light-shielding material, a decrease in the aperture ratio by increasing this ratio may be a problem, so that the ratio of the opening 14a overlapping with the bus line 18 is What is necessary is just to set it according to the use of a liquid crystal display device, etc. in consideration of desired response characteristic and aperture ratio.

Of course, not only the opening part 14a located between two adjacent unit solid parts 14b ', but also the other opening part 14a which adjoins the bus line 18 may be comprised so that it may overlap with the bus line 18. As shown in FIG. For example, like the liquid crystal display device 100A shown in FIG. 17, of the plurality of openings 14a of the recovery electrode 14, all of the openings 14a close to the gate bus line 15 are connected to the bus line ( You may be comprised so that it may overlap with 18).

In the liquid crystal display device 100 shown in FIG. 12, the opening portion 14a not overlapping with the bus line 18 in each portion (near the intersection of the gate bus line 15 and the source bus line 16) in the recovery area. In the liquid crystal display device 100A shown in Fig. 17, the edges of the gate bus lines 15 are covered with the unit solid portions 14b 'also at the respective parts of the recovery area, so that the gate bus lines ( All of the openings 14a proximate to 15 overlap with the bus line 18.

In the liquid crystal display device 100A shown in FIG. 17, since a larger portion of the edge of the bus line 18 is covered with the unit solid portion 14b ′ of the recovery electrode 14, the alignment disturbance is suppressed. The effect is high. However, when the opening part 14a of each part of a recovery area | region is also overlapped with the bus line 18, the area of the intersection part of the gate bus line 15 and the source bus line 16 is larger than the structure shown in FIG. It may become large, and parasitic capacitance may become large. Therefore, although the structure shown in FIG. 17 is preferable from a viewpoint of suppressing the disorder of an orientation, it can be said that the structure shown in FIG. 12 is preferable from a viewpoint of reduction of parasitic capacitance. Of course, as shown in FIG. 12, of the openings 14a close to the bus line 18, the openings close to the gate bus line 15 and located between adjacent unit solid portions 14b ′ ( If 14a) overlaps with the bus line 15, the disturbance of the orientation can be sufficiently suppressed, and a sufficiently high display quality can be obtained.

In addition, in FIG. 12 and FIG. 17, the case where the gate bus line 15 has the branch part which protruded toward the opening part 14a is shown about the case where the opening part 14a and the gate bus line 15 overlap. However, the present invention is of course not limited thereto. As in the liquid crystal display device 100B shown in FIG. 18, the width of the gate bus line 15 is made thick, whereby the opening 14a and the gate bus line 15 proximate the gate bus line 15 are formed. It may be overlapped (so that the edges of the gate bus lines 15 are covered with the unit solid portions 14b 'of the recovery electrode 14). However, when the width of the gate bus line 15 is made thicker, the area of the region where the gate bus line 15 and the unit solid portion 14b 'overlap with each other becomes larger than the configuration shown in Figs. The parasitic capacity between the drains increases. In addition, when the gate bus line 15 is formed with the light-shielding material, the aperture ratio is lower than that shown in FIGS. 12 and 17. Therefore, the structure shown in FIG. 12 and FIG. 17 is preferable from a viewpoint of reduction of parasitic capacitance and improvement of aperture ratio.

In addition, when driving the liquid crystal display device 100, since a large voltage is generally applied to the gate bus line 15 in comparison with the source bus line 16, it is generated near the edge of the gate bus line 15. The inclined electric field has a greater influence on the liquid crystal molecules than the inclined electric field generated near the edge of the source bus line 16.

Therefore, as in the liquid crystal display devices 100 and 100A shown in FIGS. 12 and 17, part or all of the openings 14a close to the gate bus line are partially or all of the openings 14a close to the bus line. By adopting a configuration overlapping with (18) (gate bus line 15), it is possible to effectively suppress the decrease in response speed and the occurrence of afterimage phenomenon, without causing an unnecessary drop in aperture ratio.

Of course, a configuration in which some or all of the openings 14a of the openings 14a adjacent to the source bus lines 16 overlap the bus lines 18 may be adopted, and the liquid crystal display device shown in FIGS. 19 and 20 ( Like 100C and 100D, a configuration in which all of the openings 14a adjacent to the gate bus line 15 and the source bus line 16 overlap with the bus line 18 may be adopted. In the liquid crystal display devices 100C and 100D shown in FIGS. 19 and 20, the source bus line 16 has a branch portion protruding toward the opening portion 14a, and the opening portion close to the gate bus line 15 ( In addition to 14a), the opening 14a adjacent to the source bus line 16 also overlaps the bus line 18.

In addition, you may comprise so that a part or all opening 14a of the opening 14a which adjoins the storage capacitor wiring 17 may overlap with the bus line 18 as needed.

In addition, this invention is not limited to the liquid crystal display device provided with the recovery electrode 14 illustrated in FIG. 12 etc., Of course, it can be applied to the liquid crystal display device provided with the recovery electrode 14 of various shapes. Various modifications can also be made to the number and arrangement of the unit solid portions 14b 'included in the collection electrode 14, and the present invention provides a relatively small number of unit solid portions 14b' included in the collection electrode 14. It is also suitably used for a liquid crystal display device, for example, a liquid crystal display device in which three unit solid portions 14b 'are arranged along the extending formation direction of the source bus line 16 for each combustion region.

The configuration of the liquid crystal display device 100 of the present embodiment described above is a well-known vertical alignment except that the recovery electrode 14 is an electrode having an opening 14a and the bus line 18 has a predetermined shape. The same structure as that of a type liquid crystal display device can be adopted, and it can manufacture by a well-known manufacturing method.

Moreover, typically, in order to vertically align liquid crystal molecules having negative dielectric anisotropy, vertical alignment films (not shown) are formed on the surface of the liquid crystal layer 30 side of the storage electrode 14 and the counter electrode 22. .

As the liquid crystal material, a nematic liquid crystal material having negative dielectric anisotropy is used. Moreover, the liquid crystal display device of a guest-host mode can also be obtained by adding a dichroic dye to the nematic liquid crystal material which has negative dielectric anisotropy. The liquid crystal display of the guest-host mode does not require a polarizing plate.

Up to this point, the bus line 18 is formed in a predetermined shape (a shape having a branch portion as shown in FIG. 12 and the like, or a wide shape as shown in FIG. 18), whereby the bus line 18 is provided. Although the case where the edge of is covered with the solid part 14b (unit solid part 14b ') of the recovery electrode 14 was demonstrated, this invention is not limited to this, The shape of the bus line 18 is changed. It is also possible to cover the edge of the bus line 18 with the solid portion 14b by arranging the unit solid portion 14b ′ (or the opening portion 14a) of the recovery electrode 14 in a predetermined arrangement without making it.

For example, as in the liquid crystal display device 100E shown in FIGS. 21A and 21B, a part of the unit solid portion 14b '(approximately two minutes of the unit solid portion 14b') near the gate bus line 15. May be formed so that the shape corresponding to 1) is located. In the liquid crystal display device 100E, since a part of the unit solid portion 14b 'is positioned near the gate bus line 15, the liquid crystal layer 30 is disposed between the recovery electrode 14 and the counter electrode 22. As shown in FIG. When a voltage is applied, a portion of the liquid crystal domain taking a radial oblique alignment state is formed in the solid portion 14b (part of the unit solid portion 14b ') near the gate bus line 15.

In the liquid crystal display device 100E, as shown in FIGS. 21A and 21B, the edge of the gate bus line 15 is part of the unit solid portion 14b '(about 2 minutes of the unit solid portion 14b'). And a branch portion for electrically connecting them. That is, the edge of the gate bus line 15 is covered with the solid portion 14b of the recovery electrode 14. Therefore, the same effects as in the liquid crystal display device 100 shown in FIG. 12 are obtained. In the liquid crystal display device 100E, since the branch portion is not formed in the gate bus line 15 or the width of the gate bus line 15 is required to be thick, the bus line 18 is formed of a light-shielding material. Even if it does, it does not cause unnecessary fall of an aperture ratio.

Table 2 shows a liquid crystal display device 100F having a liquid crystal display device 100E shown in FIGS. 21A and 21B and a gate bus line 15 having branch portions as shown in FIGS. 22A and 22B. And aperture ratio and aperture ratio (ratio of aperture ratio of liquid crystal display device 100E to aperture ratio of liquid crystal display device 100F).

13 inches 15 inches 20 inches 22 inches Aperture Aperture ratio Aperture Aperture ratio Aperture Aperture ratio Aperture Aperture ratio LCD (100F) 51.2% 101.2% 57.4% 100.9% 57.9% 100.8 58.3% 100.9% LCD (100E) 51.8% 58.0% 58.3% 58.8%

As shown in Table 2, in the liquid crystal display device 100E, the aperture ratio can be improved by about 1% (0.8% to 1.2%) for any of 13-inch, 15-inch, 20-inch, and 22-inch liquid crystal panels. . In addition, the numerical value of Table 2 is a numerical value with respect to arbitrary specifications, and of course, higher improvement of aperture ratio can be expected depending on the specification of a liquid crystal display device.

21A and 21B show the case where the edge of the gate bus line 15 is covered by the solid portion 14b of the recovery electrode 14, but the gate bus line 15 and the source bus line 16 are shown. It is preferable that at least one of the edges is covered with the solid portion 14b of the recovery electrode 14, and as with the liquid crystal display device 100G shown in Fig. 23, the gate bus line 15 and the source bus line ( You may arrange | position the unit solid part 14b 'so that the edges of both of 16 may be covered by the solid part 14b of the collection electrode 14. As shown in FIG. In the liquid crystal display device 100G, as shown in FIG. 23, a portion of the unit solid portion 14b '(approximately 1/2 of the unit solid portion 14b') is also provided near the source bus line 16. Shape), whereby the edge of the source bus line 16 is also covered with the solid portion 14b of the recovery electrode 14. Therefore, the further improvement of the effect which suppresses the disorder of an orientation can be aimed at.

In this way, by appropriately setting the arrangement of the unit solid portions 14b '(of the opening portions 14a) of the recovery electrode 14, it is possible to suppress the disturbance of the orientation without changing the shape of the bus line 18. have. 24A and 24B and FIGS. 25A and 25B show other liquid crystal display devices 100H and 100I of the embodiment according to the present invention.

Also in any of the liquid crystal display devices 100H and 100I, the shape of the unit solid part 14b 'of the recovery electrode 14 has eight sides (edges), and has the 4th rotation axis in the center approximately Star. In addition, the opening part 14a is substantially rhombic.

In the liquid crystal display device 100H, as shown in FIGS. 24A and 24B, the edges of the gate bus lines 15 are zigzag, whereby the edges of the gate bus lines 15 are moved electrodes 14. Is covered with a solid portion 14b. In contrast, in the liquid crystal display device 100I, as shown in FIGS. 25A and 25B, a part of the substantially solid unit solid portion 14b ′ near the gate bus line 15 and the source bus line 16 is formed. (A shape corresponding to about one half) is disposed so that the edges of the gate bus line 15 and the source bus line 16 are covered with the solid portion 14b of the recovery electrode 14. . Therefore, in the liquid crystal display device 100I, unnecessary reduction of the aperture ratio can be prevented.

<Other Embodiments>

26A and 26B, the structure of one recovery area of the liquid crystal display 200 of another embodiment according to the present invention will be described. In addition, in the following drawings, the component which has the function substantially the same as the component of the liquid crystal display device 100 is shown with the same code | symbol, and the description is abbreviate | omitted. FIG. 26A is a top view seen from the substrate normal direction, and FIG. 26B corresponds to a cross sectional view taken along the line 26B-26B 'in FIG. 26A. 26B illustrates a state in which no voltage is applied to the liquid crystal layer.

26A and 26B, in the liquid crystal display device 200, the TFT substrate 200a has a convex portion 40 inside the opening portion 14a of the recovery electrode 14. It is different from the liquid crystal display device 100 of the embodiment shown in 1A and 1B. A vertical alignment film (not shown) is formed on the surface of the convex portion 40.

The cross-sectional shape of the convex part 40 in the in-plane direction of the board | substrate 11 is the same as that of the opening part 14a, as shown in FIG. 26A, and is substantially star-shaped here. However, adjacent convex parts 40 are mutually connected, and are formed so that the unit solid part 14b 'may be completely enclosed in a substantially circular shape. The cross-sectional shape of the convex part 40 in the in-plane direction perpendicular to the substrate 11 is trapezoidal as shown in FIG. 26B. That is, it has a top space 40t parallel to a board | substrate surface, and the side surface 40s inclined by taper angle (theta) (<90 degrees) with respect to a board | substrate surface. Since the vertical alignment film (not shown) is formed so as to cover the convex portion 40, the side surface 40s of the convex portion 40 has a gradient electric field with respect to the liquid crystal molecules 30a of the liquid crystal layer 30. It has an orientation regulation force in the same direction as the orientation regulation direction, and acts to stabilize the radial oblique orientation.

The operation of the convex portion 40 will be described with reference to Figs. 27A to 27D, and Figs. 28A and 28B.

First, referring to FIGS. 27A to 27D, the relationship between the alignment of the liquid crystal molecules 30a and the shape of the surface having vertical alignment is described.

As shown in FIG. 27A, the liquid crystal molecules 30a on the horizontal surface are oriented perpendicular to the surface by the alignment regulating force of the surface having the vertical alignment property (typically, the surface of the vertical alignment film). When an electric field represented by an equipotential line EQ perpendicular to the axial orientation of the liquid crystal molecules 30a is applied to the liquid crystal molecules 30a in the vertical alignment state as described above, the liquid crystal molecules 30a are inclined clockwise or counterclockwise. Torque is acting with equal probability. Therefore, in the liquid crystal layer 30 between the electrodes of parallel plate-type arrangement | positioning which oppose each other, the liquid crystal molecule 30a which receives the torque of a clockwise rotation direction, and the liquid crystal molecule 30a which receives the torque of a counterclockwise rotation direction are mixed. do. As a result, the change to the orientation state according to the voltage applied to the liquid crystal layer 30 may not occur smoothly.

As shown in FIG. 27B, when an electric field represented by a horizontal equipotential line EQ is applied to the liquid crystal molecules 30a oriented perpendicular to the inclined surface, the liquid crystal molecules 30a are equal to the equipotential line EQ. The inclination amount to be parallel is inclined in a direction (clockwise in the illustrated example). Further, as shown in FIG. 27C, the liquid crystal molecules 30a vertically aligned with respect to the horizontal surface are aligned so that the liquid crystal molecules 30a are vertically aligned with respect to the inclined surface so that the alignment is continuous (aligned). Inclined in the same direction (clockwise) as the liquid crystal molecules 30a positioned on the inclined surface.

As shown in Fig. 27D, for continuous concave-convex surfaces having a trapezoidal cross section, the liquid crystal molecules 30a on the top and bottom surfaces are matched with the alignment direction regulated by the liquid crystal molecules 30a on each inclined surface. ) Is oriented.

The liquid crystal display device of the present embodiment stabilizes the radial inclination orientation by matching the direction of the orientation regulation force due to the shape (convex portion) of the surface with the orientation regulation direction by the gradient electric field.

28A and 28B show a state where a voltage is applied to the liquid crystal layer 30 shown in FIG. 26B, respectively, and FIG. 28A shows liquid crystal molecules 30a according to the voltage applied to the liquid crystal layer 30. Schematically shows a state in which the orientation of? Starts to change (ON initial state), and FIG. 28B schematically shows a state in which the orientation of the liquid crystal molecules 30a changed in accordance with the applied voltage reaches a steady state. have. Curve EQ in FIGS. 28A and 28B represents equipotential line EQ.

When the recovery electrode 14 and the counter electrode 22 are at the same potential (no voltage is applied to the liquid crystal layer 30), as shown in FIG. 26B, the liquid crystal molecules 30a in the recovery region And orthogonal to the surfaces of both substrates 11 and 21. At this time, the liquid crystal molecules 30a in contact with the vertical alignment film (not shown) of the side surface 40s of the convex portion 40 are vertically oriented with respect to the side surface 40s, and the liquid crystal molecules (near the side surfaces 40s) ( 30a) takes inclined orientation as shown by the interaction (nature as an elastic body) with the surrounding liquid crystal molecules 30a.

When a voltage is applied to the liquid crystal layer 30, a potential gradient represented by the equipotential line EQ shown in Fig. 28A is formed. This equipotential line EQ is applied to the surfaces of the solid portion 14b and the counter electrode 22 in the liquid crystal layer 30 positioned between the solid portion 14b and the counter electrode 22 of the recovery electrode 14. On the EG parallel and falling in the area corresponding to the opening 14a of the recovery electrode 14, the edge of the opening 14a (the inner periphery of the opening 14a including the boundary (outer edge) of the opening 14a) In the liquid crystal layer 30, a gradient electric field represented by an inclined equipotential line EQ is formed.

By the inclination electric field, as described above, the liquid crystal molecules 30a on the edge portion EG are clockwise in the right edge portion EG of the figure and half in the left edge portion EG of the figure, as indicated by arrows in FIG. 28A. In the clockwise direction, each is inclined (rotated) and oriented parallel to the equipotential line EQ. The orientation regulation direction by this inclination electric field is the same as the orientation regulation direction by the side surface 40s located in each edge part EG.

As described above, when the orientation change starting from the liquid crystal molecules 30a positioned on the inclined equipotential line EQ progresses and reaches a steady state, the orientation state schematically shown in FIG. 28B is obtained. The liquid crystal molecules 30a positioned near the center of the opening portion 14a, that is, near the center of the top surface 40t of the convex portion 40, have the liquid crystal molecules of the edge portions EG on both sides of the opening portion 14a facing each other. Since the influence of the alignment of 30a is almost equal, the liquid crystal molecules in the region away from the center of the opening 14a (top surface 40t of the convex portion 40) are maintained while maintaining the alignment perpendicular to the equipotential line EQ. 30a is inclined under the influence of the alignment of the liquid crystal molecules 30a of the edge portion EG near each other, and is symmetric with respect to the center SA of the opening portion 14a (top surface 40t of the convex portion 40). To form an oblique orientation. Further, even in a region corresponding to the unit solid portion 14b 'substantially surrounded by the opening portion 14a and the convex portion 40, an inclined orientation symmetrical with respect to the center SA of the unit solid portion 14b' is formed. .

As described above, also in the liquid crystal display device 200 of the present embodiment, similarly to the liquid crystal display device 100, a liquid crystal domain having a radial oblique alignment is formed corresponding to the opening portion 14a and the unit solid portion 14b '. Since the convex portion 40 is formed so as to completely surround the unit solid portion 14b 'in a substantially circular shape, the liquid crystal domain is formed corresponding to the substantially circular region surrounded by the convex portion 40. Moreover, the side surface of the convex part 40 formed in the inside of the opening part 14a acts to incline the liquid crystal molecule 30a of the edge part EG of the opening part 14a to the same direction as the orientation direction by a gradient electric field. Therefore, the radial oblique orientation is stabilized.

Although the orientation regulating force by the gradient electric field is natural, it acts only when a voltage is applied, and the strength depends on the electric field strength (the magnitude of the applied voltage). Therefore, when the electric field strength is weak (that is, when the applied voltage is low), the alignment regulating force by the gradient electric field is weak, and when the external force is applied to the liquid crystal panel, the radial oblique orientation may collapse due to the flow of the liquid crystal material. Once the radial oblique orientation collapses, the radial oblique orientation is not restored unless a voltage is applied that is sufficient to produce a gradient electric field exhibiting a sufficiently strong orientation regulating force. On the other hand, the orientation regulation force by the side surface 40s of the convex part 40 acts irrespective of an applied voltage, and is very strong, as it is known as an anchoring effect of an oriented film. Therefore, even if the flow of the liquid crystal material occurs and the radial oblique alignment collapses once, the liquid crystal molecules 30a near the side surface 40s of the convex portion 40 maintain the same alignment direction as in the radial oblique alignment. Therefore, as long as the flow of the liquid crystal material is stopped, the radial inclination orientation is easily restored.

As described above, the liquid crystal display device 200 according to the present embodiment has a feature of being strong against external force in addition to the characteristics of the liquid crystal display device 100. Accordingly, the liquid crystal display device 200 is suitably used for a personal computer or a PDA, which is easily applied with an external force and has many opportunities for carrying.

Moreover, when the convex part 40 is formed using the dielectric with high transparency, the advantage that the contribution ratio to the display of the liquid crystal domain formed corresponding to the opening part 14a is improved is acquired. On the other hand, when the convex portion 40 is formed using an opaque dielectric, light leakage due to retardation of the liquid crystal molecules 30a inclined by the side surface 40s of the convex portion 40 is prevented. The advantage that it can prevent is obtained. What is adopted may be determined according to the use etc. of a liquid crystal display device. In any case, the use of the photosensitive resin has the advantage of simplifying the process of patterning corresponding to the opening 14a. In order to acquire sufficient orientation control force, it is preferable that the height of the convex part 40 exists in the range of about 0.5 micrometer-about 2 micrometers when the thickness of the liquid crystal layer 30 is about 3 micrometers. In general, the height of the convex portion 40 is preferably in the range of about 1/6 to about 2/3 of the thickness of the liquid crystal layer 30.

As above-mentioned, the liquid crystal display device 200 has the convex part 40 inside the opening part 14a of the recovery electrode 14, and the side surface 40s of the convex part 40 has the liquid-crystal layer 30 With respect to the liquid crystal molecules 30a of), it has an orientation regulation force in the same direction as the orientation regulation direction by the gradient electric field. Preferred conditions for the side surface 40s to have the orientation regulating force in the same direction as the orientation regulation direction by the gradient electric field will be described with reference to FIGS. 29A to 29C.

29A to 29C schematically show cross-sectional views of the liquid crystal display devices 200A, 200B, and 200C, respectively, and correspond to FIG. 28A. Although all of the liquid crystal display devices 200A, 200B, and 200C have a convex portion inside the opening 14a, the arrangement relationship between the entire convex portion 40 and the opening portion 14a as one structure is different from that of the liquid crystal display device 200. different.

In the above-mentioned liquid crystal display device 200, as shown in FIG. 28A, the whole convex part 40 as a structure is formed in the inside of the opening part 14a, and the bottom face of the convex part 40 is an opening part ( Less than 40a). In the liquid crystal display device 200A shown in FIG. 29A, the bottom surface of the convex portion 40A coincides with the opening portion 14a. In the liquid crystal display device 200B shown in FIG. 29B, the convex portion 40B is the opening portion. It has a bottom face larger than 14a, and is formed so as to cover the solid portion (conductive film) 14b around the opening 14a. The solid part 14b is not formed on the side surface 40s of any of these convex parts 40, 40A, and 40B. As a result, as shown in each figure, the equipotential line EQ is almost flat on the solid part 14b, and falls from the opening part 14a as it is. Therefore, the side surfaces 40s of the convex portions 40A and 40B of the liquid crystal display devices 200A and 200B are the same as the alignment regulating force by the inclined electric field, similarly to the convex portions 40 of the liquid crystal display device 200 described above. Exhibit orientation control force in the direction to stabilize the radial oblique orientation.

On the other hand, the bottom surface of the convex part 40C of the liquid crystal display 200C shown in FIG. 29C is larger than the opening part 14a, and the solid part 14b around the opening part 14a is the side surface of the convex part 40C. 40s). Under the influence of the solid portion 14b formed on the side surface 40s, an acid is formed in the equipotential line EQ. The peak of the equipotential line EQ has an inclination opposite to that of the equipotential line EQ falling from the opening 14a, which indicates that a slope electric field is generated in a direction opposite to the inclination electric field for radially orienting the liquid crystal molecules 30a. . Therefore, in order for the side surface 40s to have the orientation control force of the same direction as the orientation control force by a gradient electric field, it is preferable that the solid part (conductive film) 14b is not formed on the side surface 40s.

Next, with reference to FIG. 30, the cross-sectional structure taken along the line 30A-30A 'of the convex part 40 shown in FIG. 26A is demonstrated.

As mentioned above, since the convex part 40 shown in FIG. 26A is formed so that the unit solid part 14b 'may be completely enclosed in a substantially circular shape, it will connect with the adjacent unit solid part 14b'. The part which plays a role (branch part extended from a circular part in all directions) is formed on the convex part 40, as shown in FIG. Therefore, in the process of depositing the conductive film which forms the solid part 14b of the collection electrode 14, there exists a high risk of disconnection on the convex part 40, or peeling in the post process of a manufacturing process.

Therefore, as in the liquid crystal display device 200D shown in FIGS. 31A and 31B, when the independent convex portions 40D are completely included in the opening portions 14a, the conductive film forming the solid portions 14b is formed. Since it is formed on the flat surface of the board | substrate 11, there exists no danger of disconnection or peeling. In addition, although the convex part 40D is not formed so that the unit solid part 14b 'may be completely enclosed in a substantially circular shape, the substantially circular liquid crystal domain corresponding to the unit solid part 14b' is formed, and As in the example, the radial oblique orientation is stabilized.

By forming the convex portion 40 in the opening portion 14a, the effect of stabilizing the radial oblique orientation is not limited to the opening portion 14a of the above-described pattern, and the same applies to the opening portions 14a of all the patterns described above. The same effect can be acquired. Moreover, in order to fully exhibit the orientation stabilization effect with respect to the external force by the convex part 40, the pattern of the convex part 40 (a pattern when it sees from the board normal line direction) is made to cover the liquid crystal layer 30 of a wide area as much as possible. It is preferable that it is a shape surrounding. Thus, for example, the positive pattern having the circular unit solid portion 14b 'has a larger orientation stabilizing effect by the convex portion 40 than the negative pattern having the circular opening portion 14a.

As described above, in the electrode structure in which the opening is formed in the recovery electrode, a sufficient voltage is not applied to the liquid crystal layer in the region corresponding to the opening, and sufficient retardation change is not obtained. It may occur. Therefore, a dielectric layer is formed on the side opposite to the liquid crystal layer of the recovery electrode (upper electrode) in which the opening is formed, and further an electrode (lower layer electrode) facing at least a part of the opening of the recovery electrode is formed through this dielectric layer (two layers). Sufficient voltage can be applied to the liquid crystal layer corresponding to the structure electrode) and the opening, and the light utilization efficiency and response characteristics can be improved.

32 shows a liquid crystal display device 300 including a storage electrode (two-layer structure electrode) 15 having a lower electrode 12, an upper electrode 14, and a dielectric layer 13 formed therebetween. The cross-sectional structure of a recovery area is shown typically. The upper electrode 14 of the recovery electrode 15 is substantially equivalent to the above-described recovery electrode 14, and has various shapes, openings, and solid portions described above. Hereinafter, the function of the recovery electrode 15 having a two-layer structure will be described.

The recovery electrode 15 of the liquid crystal display device 300 has a plurality of openings 14a (including 14a1 and 14a2). FIG. 32A schematically illustrates the alignment state (OFF state) of liquid crystal molecules 30a in the liquid crystal layer 30 to which no voltage is applied. 32B schematically shows a state in which the orientation of the liquid crystal molecules 30a starts to change (ON initial state) in accordance with the voltage applied to the liquid crystal layer 30. 32C schematically shows a state in which the orientation of the liquid crystal molecules 30a changed in accordance with the applied voltage reaches a steady state. In FIG. 32, the lower electrode 12 formed so as to face the openings 14a1 and 14a2 via the dielectric layer 13 overlaps with each of the openings 14a1 and 14a2, and is located between the openings 14a1 and 14a2. Although the example formed so that it may exist also in the area | region (the area | region in which the upper electrode 14 exists) was shown, the arrangement | positioning of the lower electrode 12 is not limited to this, The lower layer electrode 12 with respect to each of opening part 14a1, 14a2 is shown. The area = may be the area of the opening 14a or the area of the lower electrode 12 <the area of the opening 14a. In other words, the lower electrode 12 may be formed to face at least a part of the opening 14a via the dielectric layer 13. However, in the structure in which the lower electrode 12 is formed in the opening part 14a, the area | region where neither the lower electrode 12 nor the upper electrode 14 exists in the plane seen from the normal line direction of the board | substrate 11 (gap area | region) Since there exists a case where sufficient voltage is not applied to the liquid crystal layer 30 of the area | region which opposes this gap area | region, it is sufficient to narrow the width | variety of this gap area | region so that the orientation of the liquid crystal layer 30 may be stabilized. It is preferred, and typically not to exceed about 4 μm. In addition, since the lower electrode 12 formed at the position opposite to the region where the conductive layer of the upper electrode 14 exists through the dielectric layer 13 does not substantially affect the electric field applied to the liquid crystal layer 30. Although it does not need to pattern specifically, You may pattern.

As shown in FIG. 32A, when the recovery electrode 15 and the counter electrode 22 are at the same potential (no voltage is applied to the liquid crystal layer 30), the liquid crystal molecules 30a in the recovery region And orthogonal to the surfaces of both substrates 11 and 21. Here, for the sake of simplicity, the potentials of the upper electrode 14 and the lower electrode 12 of the recovery electrode 15 are assumed to be the same.

When a voltage is applied to the liquid crystal layer 30, a potential gradient represented by the equipotential line EQ shown in Fig. 32B is formed. In the liquid crystal layer 30 positioned between the upper electrode 14 and the counter electrode 22 of the recovery electrode 15, an equipotential line EQ parallel to the surfaces of the upper electrode 14 and the counter electrode 22 is provided. A uniform potential gradient is formed, which is indicated. In the liquid crystal layer 30 positioned on the openings 14a1 and 14a2 of the upper electrode 14, a potential gradient according to the potential difference between the lower electrode 12 and the counter electrode 22 is formed. At this time, since the potential gradient formed in the liquid crystal layer 30 is affected by the voltage drop caused by the dielectric layer 13, the equipotential line EQ formed in the liquid crystal layer 30 corresponds to the openings 14a1 and 14a2. It falls in the area to be made (plural "valleys" are formed in the equipotential line EQ). Since the lower electrode 12 is formed in the region facing the openings 14a1 and 14a2 through the dielectric layer 13, even in the liquid crystal layer 30 located near the center of each of the openings 14a1 and 14a2. The potential gradient represented by the equipotential line EQ parallel to the surfaces of the upper electrode 14 and the counter electrode 22 is formed (the "bottom of the valley" of the equipotential line EQ). In the liquid crystal layer 30 on the edge portion of the openings 14a1 and 14a2 (the inner periphery of the opening including the boundary (outer edge) of the opening)) EG, a gradient electric field represented by an inclined equipotential line EQ is formed.

As apparent from the comparison between FIG. 32B and FIG. 2A, since the liquid crystal display device 300 has the lower electrode 12, an electric field having a sufficient size for the liquid crystal molecules of the liquid crystal domain formed in the region corresponding to the opening 14a. Can act.

A torque for aligning the axial orientation of the liquid crystal molecules 30a in parallel with the equipotential line EQ acts on the liquid crystal molecules 30a having negative dielectric anisotropy. Accordingly, the liquid crystal molecules 30a on the edge portion EG are inclined (rotated) in the clockwise direction in the right edge portion EG in the figure and counterclockwise in the left edge portion EG in the figure, as indicated by the arrows in FIG. 32B. To parallel to the equipotential line EQ.

As shown in FIG. 32B, in the edge portions EG of the opening portions 14a1 and 14a2 of the liquid crystal display device 300, an electric field represented by an equipotential line EQ inclined with respect to the axial orientation of the liquid crystal molecules 30a (an inclined electric field). When is generated, as shown in Fig. 3B, the liquid crystal molecules 30a are inclined in a direction (anticlockwise direction in the illustrated example) where the amount of inclination for parallel with the equipotential line EQ is small. Further, as shown in FIG. 3C, the liquid crystal molecules 30a positioned in the region where the electric field represented by the equipotential line EQ in the vertical direction with respect to the axial orientation of the liquid crystal molecules 30a are inclined. It is inclined in the same direction as the liquid crystal molecules 30a positioned on the inclined equipotential line EQ so that the alignment with the liquid crystal molecules 30a positioned in the (continuously) is aligned.

As described above, when the orientation change starting from the liquid crystal molecules 30a positioned on the inclined equipotential line EQ progresses and reaches a steady state, as shown schematically in FIG. 32C, the openings 14a1, 14a2) form a symmetrical oblique orientation (radial oblique orientation) with respect to each center SA. Further, the liquid crystal molecules 30a on the region of the upper electrode 14 positioned between two adjacent openings 14a1 and 14a2 are also arranged so that the alignment of the liquid crystal molecules 30a at the edge portions of the openings 14a1 and 14a2 is continuous. It is diagonally oriented (to be matched). Since the liquid crystal molecules 30a on the portion located at the center of the edges of the openings 14a1 and 14a2 are subjected to the same degree of influence of the liquid crystal molecules 30a of the respective edge portions, the liquid crystal molecules 30a are located at the center of the openings 14a1 and 14a2. Similar to the liquid crystal molecules 30a, the vertical alignment state is maintained. As a result, the liquid crystal layer on the upper electrode 14 is also in a radial oblique alignment state between two adjacent openings 14a1 and 14a2. However, the inclination direction of the liquid crystal molecules is different in the radial inclination orientation of the liquid crystal layer in the openings 14a1 and 14a2 and the radial inclination direction of the liquid crystal layer between the openings 14a1 and 14a2. Note the orientation in the vicinity of the liquid crystal molecules 30a located in the center of each radially oriented region shown in Fig. 32C, so that in the openings 14a1 and 14a2, a cone is formed that extends toward the counter electrode. While the liquid crystal molecules 30a are inclined, the liquid crystal molecules 30a are inclined between the openings so as to form a cone that extends toward the upper electrode 14. Moreover, since any radial oblique orientation is formed so as to match the oblique orientation of the liquid crystal molecules 30a of the edge portion, the two radial oblique orientations are continuous with each other.

As described above, when a voltage is applied to the liquid crystal layer 30, the liquid crystal molecules 30a on the edge portion EG of each of the plurality of openings 14a1 and 14a2 formed in the upper electrode 14 start to be inclined. After the liquid crystal molecules 30a in the peripheral region are inclined to match the inclination orientation of the liquid crystal molecules 30a on the edge portion EG, a radial inclination orientation is formed. Therefore, the larger the number of openings 14a formed in one recovery area, the greater the number of liquid crystal molecules 30a starting to incline in response to an electric field for the first time, which is necessary to form a radial oblique orientation over the entire recovery area. The time gets shorter. That is, the response speed of the liquid crystal display device can be improved by increasing the number of openings 14a formed in the recovery electrode 15 for each recovery region. In addition, since the storage electrode 15 is a two-layer structure electrode having the upper layer electrode 14 and the lower layer electrode 12, a sufficient electric field can be applied to the liquid crystal molecules in the region corresponding to the opening portion 14a. The response characteristic of the display device is improved.

Further, in order to further stabilize the alignment of the liquid crystal domain having a radial oblique alignment, the convex portion for radial oblique alignment of the liquid crystal molecules cooperatively with the alignment control structure (the electrode structure having the opening described above) of the TFT substrate is provided on the opposing substrate. You may form.

33A and 33B show a liquid crystal display device 400 having a convex portion 28 formed on the opposing substrate 400b. FIG. 33A is a top view and FIG. 33B corresponds to a sectional view taken along the line 33B-33B 'in FIG. 33A.

The liquid crystal display device 400 has a TFT substrate 100a having a recovery electrode 14 having an opening 14a formed therein, and an opposing substrate 400b having a convex portion 28 protruding toward the liquid crystal layer 30 side. have. In addition, as the TFT substrate 100a, it is not limited to the structure illustrated here, The above-mentioned various structures can be used suitably.

The convex part 28 formed on the opposing board | substrate 400b has the side surface 28s inclined with respect to the board | substrate surface (substrate surface of the transparent board | substrate 11) of the opposing board | substrate 400b, and here, convex part ( 28 is formed on the counter electrode 22.

The surface of the convex portion 28 has a vertical alignment property (typically, a vertical alignment film (not shown) is formed to cover the convex portion 28), and as shown in FIG. 33B, the liquid crystal molecules ( 30a) is oriented almost perpendicularly to these by the anchoring effect of the inclined side 28s. For this reason, the liquid crystal molecules 30a around the convex portion 28 radially incline to the center of the convex portion 28. That is, the convex part 28 acts to radially incline the liquid crystal molecules 30a by the shape effect of the surface (having vertical alignment).

In addition, the convex part 28 is formed in the area | region facing the solid part 14b of the recovery electrode 14, More specifically, it is formed so as to oppose the center vicinity of the unit solid part 14b '. . Since the convex part 28 is arrange | positioned in this way, the inclination direction of the liquid crystal molecule by the convex part 28 is located in the area | region corresponding to the unit solid part 14b 'of the recovery electrode 14 by an orientation control structure. Match with the orientation direction of the radial oblique alignment of the liquid crystal domain to be formed. Since the convex part 28 expresses an orientation regulation force irrespective of whether a voltage is applied or not, stable radial oblique orientation is obtained at all display gradations, and is also excellent in resistance to stress.

As described above, in the liquid crystal display device 400, in the state where a voltage is applied to the liquid crystal layer 30, that is, in a state where a voltage is applied between the recovery electrode 14 and the counter electrode 22, the alignment control structure. The direction of the radial inclination orientation formed by the coincidence and the direction of the radial inclination orientation formed by the convex portion 28 are matched, and the radial inclination orientation is stabilized. This state is shown typically in FIGS. 34A-34C. Fig. 34A shows the time when no voltage is applied, Fig. 34B shows the state in which the orientation has started to change after the voltage is applied (ON initial state), and Fig. 34C schematically shows the steady state during voltage application.

As shown in FIG. 34A, the alignment regulating force by the convex portion 28 acts on the liquid crystal molecules 30a in the vicinity even in a voltage-free state to form radial oblique alignment.

When voltage is applied, the electric field represented by the equipotential line EQ as shown in Fig. 34B is generated (by the alignment control structure), and the liquid crystal molecules 30a are formed in the regions corresponding to the openings 14a and the solid portions 14b. A radially tilted liquid crystal domain is formed, and reaches a steady state as shown in Fig. 34C. At this time, the inclination direction of the liquid crystal molecules 30a in the liquid crystal domain formed in the region corresponding to the solid portion 14b is inclined by the alignment regulating force of the convex portion 28 formed in the corresponding region. Coincides with the direction.

When stress is applied to the liquid crystal display device 400 in a steady state, the radial oblique alignment of the liquid crystal layer 30 collapses once, but when the stress is removed, the alignment regulating structure and the alignment regulating force by the convex portion 28 become liquid crystal. Because it is acting on the molecule 30a, it returns to the radial oblique alignment state. Therefore, generation | occurrence | production of an afterimage by stress is suppressed.

In addition, since the orientation regulating force by the convex part 28 only needs to have the effect of stabilizing the radial inclination orientation formed by the orientation regulating structure and fixing the central axis position, the strong orientation regulating force is not necessary. For example, with respect to the unit solid portion 14b 'having a diameter of about 30 µm to about 50 µm, the convex portions 28 having a diameter of about 15 µm and a height (thickness) of about 1 µm are formed, respectively, to provide sufficient orientation. Regulatory power is obtained.

Although there is no restriction | limiting in particular in the material which forms the convex part 28, It can form easily using dielectric materials, such as resin. It is also preferable to use a resin material deformed by heat because the convex portion 28 having a cross-sectional shape on a gentle hill can be easily formed by heat treatment after patterning as shown in Fig. 33B. Do. As shown in the figure, the convex portion 28 having a smooth shape having a vertex (cross-sectional shape along the normal of the substrate surface) is excellent in fixing the center position of the radial inclination orientation. Of course, the convex portion may have a top surface.

In addition, although the convex part 28 whose cross-sectional shape (cross-sectional shape along the board surface of the opposing board | substrate 400b) is substantially circular was illustrated in FIG. 33A, the cross-sectional shape of the convex part 28 is not limited to this, and is substantially the same. It may be spherical or approximately cross-shaped. From the viewpoint of reducing the viewing angle dependency, it is preferable that the cross-sectional shape of the convex portion has high rotational symmetry.

FIG. 35 shows a liquid crystal display device 400A having a convex portion 28A having a substantially cross-sectional shape. The liquid crystal display device 400A has substantially the same configuration as the liquid crystal display device 400 shown in FIGS. 33A and 33B except that the cross-sectional shape of the convex portion 28A is approximately cross-shaped.

The convex portion 28A having a substantially cross-sectional shape has a larger area of the inclined side surface which exerts an orientation restricting force on the liquid crystal molecules 30a than the convex portion having a cross-sectional shape having an approximately the same area in a substantially circular shape. It can exert an orientation control over a broader range within the liquid crystal domain. Therefore, a larger orientation regulating force can be effectively exerted on the liquid crystal molecules 30a. Therefore, in the liquid crystal display device 400A having the convex portion 28A having a substantially cross-sectional shape, the alignment is further stabilized and the response speed when a voltage is applied is improved.

Of course, the convex portions having different cross-sectional shapes (cross-sectional shape along the substrate surface) may be mixed on the opposing substrate. For example, in an area (e.g., near a bus line) where an unnecessary electric field that adversely affects display is likely to occur, a convex portion having a large orientation control force (for example, a cross-sectional shape shown in FIG. 35 is substantially cross-shaped to improve the orientation control force). The convex part 28A) may be formed, and convex parts different from these may be formed in other areas.

36 and 37 show liquid crystal display devices 400B and 400C having constitutions in which convex portions having different cross-sectional shapes are mixed on the opposing substrate 400b.

The TFT substrate of the liquid crystal display device 400B shown in FIG. 36 is similar to the liquid crystal display device 100E shown in FIGS. 21A and 21B so that the unit solid portion 14b 'is located near the gate bus line 15. It has the recovery electrode 14 formed so that a part (shape equivalent to about half of unit solid part 14b ') may be located. The opposing board | substrate of liquid crystal display device 400B has the convex part 28B which is substantially T-shaped in cross-sectional shape in the area | region corresponding to a part of unit solid part 14b 'of the vicinity of the gate bus line 15, In the area | region corresponding to the unit solid part 14b ', it has the convex part 28 whose cross-sectional shape is substantially circular.

The inclination direction of the liquid crystal molecules 30a by the approximately T-shaped convex portion 28B is a part of the unit solid portion 14b 'in the vicinity of the gate bus line 15 (a shape corresponding to about one half). Match with the orientation direction of the radial oblique alignment of a portion of the liquid crystal domain formed correspondingly. The approximately T-shaped convex part 28B formed corresponding to a part (shape equivalent to about 1/2) of the unit solid part 14b 'is a substantially cross-shaped convex formed corresponding to the unit solid part 14b'. For the same reason as the portion 28A, a larger alignment regulating force can be effectively exerted on the liquid crystal molecules 30a.

Therefore, in the liquid crystal display device 400B in which the convex portion 28B having a large alignment control force is formed in the vicinity of the gate bus line 15, the alignment of the liquid crystal molecules 30a near the gate bus line 15 where the alignment is liable to be disturbed. Can be effectively regulated.

The TFT substrate of the liquid crystal display device 400C shown in FIG. 37 has a unit solid portion (near the gate bus line 15 and the source bus line 16) similarly to the liquid crystal display device 100G shown in FIG. 23. 14b ') has the recovery electrode 14 formed so that a part (shape equivalent to about 1/2 of the unit solid part 14b') may be located. The opposing substrate of the liquid crystal display device 400C has a convex shape having a substantially T-shaped cross-sectional shape in a region corresponding to a part of the unit solid portion 14b 'in the vicinity of the gate bus line 15 and the source bus line 16. It has the part 28B and has the convex part 28 which is substantially circular in cross-sectional shape in the area | region corresponding to the unit solid part 14b '.

In the liquid crystal display device 400C, since the convex portion 28B having a large alignment regulating force is formed in the vicinity of the gate bus line 15 and in the vicinity of the source bus line 16, the vicinity of the gate bus line 15 and the source bus line (16) The orientation of the liquid crystal molecules 30a in the vicinity can be effectively regulated.

(Position of polarizing plate and retardation plate)

The so-called vertically oriented liquid crystal display device having a liquid crystal layer in which liquid crystal molecules having negative dielectric anisotropy are vertically aligned when no voltage is applied can display in various display modes. For example, in addition to the birefringence mode displayed by controlling the birefringence of the liquid crystal layer by an electric field, it is applied to the display mode by combining the beneficiation mode, the beneficiation mode and the birefringence mode. By providing a pair of polarizing plates on the outer side (the opposite side to the liquid crystal layer 30) of the pair of substrates (for example, the TFT substrate and the counter substrate) of all the liquid crystal display devices described in the above embodiments, the liquid crystal display device in the birefringence mode Can be obtained. If necessary, a phase difference compensating element (typically a phase difference plate) may be provided. Moreover, even if circularly polarized light is used, a bright liquid crystal display device can be obtained.

<Other Embodiments>

The degradation of display quality due to the inclined electric field generated near the edge of the bus line is a liquid crystal display having an alignment regulating structure (electrode structure having unit solid portions and openings) for forming a liquid crystal domain having a radial oblique alignment state. In addition to the device, a liquid crystal layer having a vertical alignment type that takes a vertical alignment state when no voltage is applied, is generated in the whole liquid crystal display device which performs the alignment regulation by an electrode structure having an opening.

According to the present invention, the display quality can be improved in the overall liquid crystal display device having a vertically aligned liquid crystal layer and performing alignment control by an electrode structure having an opening.

38A and 38B, the structure of a liquid crystal display 500 of still another embodiment according to the present invention will be described. FIG. 38A is a top view seen from the substrate normal direction, and FIG. 38B corresponds to a cross-sectional view taken along the line 38B-38B 'in FIG. 38A. 38A and 38B show a state where a voltage is applied to the liquid crystal layer.

The liquid crystal display device 500 includes an active matrix substrate (hereinafter referred to as a "TFT substrate") 500a, an opposing substrate (called a "color filter substrate") 500b, a TFT substrate 500a, and an opposing substrate. It has the liquid crystal layer 30 of the vertical alignment type formed between 500b.

The liquid crystal molecules 30a included in the liquid crystal layer 30 have negative dielectric anisotropy and are vertical alignment films as vertical alignment layers formed on the surfaces of the liquid crystal layer 30 side of the TFT substrate 500a and the opposing substrate 500b. (Not shown), when no voltage is applied to the liquid crystal layer 30, it is oriented perpendicular to the surface of the vertical alignment film.

The TFT substrate 500a of the liquid crystal display device 500 has a transparent substrate (for example, a glass substrate) 11 and a recovery electrode 19 formed on the surface thereof. The opposing board | substrate 500b has the transparent board | substrate (for example, glass substrate) 21, and the opposing electrode 22 formed in the surface. According to the voltage applied to the recovery electrode 19 and the counter electrode 22 which are disposed to face each other via the liquid crystal layer 30, the alignment state of the liquid crystal layer 30 for each recovery region is changed. With the change of the orientation state of the liquid crystal layer 30, display is performed using the phenomenon in which the polarization state or quantity of the light which permeate | transmits the liquid crystal layer 30 changes.

The recovery electrode 19 of the TFT substrate 500a has a plurality of opening portions 19a and a solid portion 19b. The opening portion 19a indicates a portion where the conductive film in the recovery electrode 19 formed of a conductive film (for example, an ITO film) is removed, and the solid portion 19b is a portion other than the opening portion 19a (the opening portion 19a). Part). A plurality of openings 19a are formed for each of the recovery electrodes, but the solid portion 19b is basically formed of a single continuous conductive film.

In this embodiment, each of the openings 19a has a slit shape (a shape in which the width (direction perpendicular to the length) is significantly narrow with respect to the length). Each of the plurality of openings 19a has sides extending in the direction of 45 ° with respect to the long side and the short side (column direction and row direction of the matrix array) of the recovery region. Further, in the upper half and the lower half of the recovery area, the direction in which the vicinity thereof extends is different by 90 degrees.

When a voltage is applied between the recovery electrode 19 and the counter electrode 22, the inner side of the opening 19a including the edge portion (boundary edge of the opening portion 19a) of the opening 19a of the recovery electrode 19 is provided. In the liquid crystal layer 30 on the periphery), a gradient electric field represented by an inclined equipotential line EQ is formed. Therefore, the liquid crystal molecules 30a having negative dielectric anisotropy in the vertical alignment state when no voltage is applied incline along the inclination direction of the inclined electric field generated at the edge portion of the opening 19a when voltage is applied. That is, the liquid crystal layer 30 is a gradient electric field generated at the edge portions of the plurality of openings 19a of the recovery electrode 19 when a voltage is applied between the recovery electrode 19 and the counter electrode 22. Orientation is regulated.

In the liquid crystal display device 500, the liquid crystal layer 30 is oriented by the gradient electric field generated at the edge portion of the opening portion 19a. As a result, when the voltage is applied, the liquid crystal molecules 30a in the recovery region are mutually 90 degrees. Orientation is carried out in four orientations which form an angle of integer multiple of °. In other words, in the liquid crystal display device 500, the recovery region is aligned in the orientation. Therefore, the liquid crystal display device 500 has favorable viewing angle characteristics.

Moreover, the opposing board | substrate 500b of the liquid crystal display device 500 has the convex part 29 on the surface of the liquid crystal layer 30 side. The convex part 29 has the inclined side surface 29s, and is formed so that the shape seen from the board surface normal line direction may become a zigzag shape. The direction in which the inclined side surface 29s extends and the direction in which the sides of the opening portion 19a extend are coincident with each other, and the convex portion 29 is substantially in the middle of two adjacent openings 19a along the width direction of the opening portion 19a. It is formed to be located.

The surface of the convex portion 29 has a vertical alignment property (typically, a vertical alignment film (not shown) is formed to cover the convex portion 29), and the liquid crystal molecules 30a have an inclined side surface 29s. By the anchoring effect of, it is oriented almost perpendicular to the inclined side surface 29s. When a voltage is applied to the liquid crystal layer 30 in this state, the other portion near the convex portion 29 is matched with the inclined orientation on the inclined side 29s due to the anchoring effect of the inclined side 29s of the convex portion 29. The liquid crystal molecules 30a are inclined.

Since the orientation regulation direction by the inclined electric field generated at the edge portion of the opening 19a of the recovery electrode 19 and the orientation regulation direction by the convex portion 29 are matched, the orientation is divided by the inclination electric field when voltage is applied. The alignment of the liquid crystal layer to be further stabilized by the convex portion 29.

The TFT substrate 500a of the liquid crystal display device 500 includes a TFT (not shown) as a switching element electrically connected to the recovery electrode 19 and a gate bus line (scan wiring) 15 electrically connected to the TFT. ) And a bus line 18 including a source bus line (signal wiring) 16.

In the present embodiment, as shown in FIG. 38A, the opening 19a of the recovery electrode 19 is formed so as not to cross the edge of the gate bus line 15, and the edge of the gate bus line 15 is formed. The solid portion 19b of the recovery electrode 19 is covered. Therefore, display of high quality is realized. This reason will be described with reference to FIGS. 38A, 38B, and 39. FIG. 39: is a top view which shows typically the liquid crystal display device 800 in which one part of the edge of the gate bus line 15 is not covered by the solid part 19b of the recovery electrode 19. As shown in FIG.

A gradient electric field is generated near the edge of the bus line 18, but this gradient electric field is generated regardless of the presence or absence of an applied voltage to the liquid crystal layer 30 between the recovery electrode 19 and the counter electrode 22. Therefore, in the liquid crystal display device which displays the display in normal black mode, when the voltage is not applied, when the liquid crystal molecules 30a on the edge of the bus line 18 are inclined under the orientation control force by this inclination electric field, light leakage occurs. It may generate | occur | produce and a contrast ratio may fall. In particular, since the relatively large voltage (off voltage) for turning off the TFT is applied to the gate bus line 15 in most cases, the occurrence of this light leakage in the vicinity of the edge of the gate bus line 15 Remarkable

In the liquid crystal display device 800, the recovery electrode 19 has an opening 19a formed to cross the edge of the gate bus line 15, as shown in FIG. 39, and the gate bus line 15. A part of the edge of is not covered by the solid portion 19b of the recovery electrode 19. Therefore, in the vicinity of the part of the edge of the gate bus line 15 which is not covered by the solid portion 19b (the area LL surrounded by the broken line in FIG. 39), the inclination generated near the edge of the gate bus line 15 is generated. The liquid crystal molecules 30a are inclined under the influence of the electric field, and light leakage occurs.

In addition, a residual electric potential tends to occur in the opening portion 19a where the insulator material is peeled off due to a gradient electric field generated near the edge of the bus line 18, and the liquid crystal in the opening portion 19a adjacent to the bus line 18. If the molecule 30a is inclined under the influence of the residual potential, it causes light leakage. The extent to which this residual potential remains depends on the surface state of the insulator material, but fluctuations occur in the surface state of the insulator material at the time of printing the alignment film or injecting the liquid crystal material. Therefore, in the liquid crystal display device, there is a variation in the residual potential in the display surface. When the residual potential varies within the display surface, the degree of light leakage varies within the display surface, so that local variations in the contrast ratio occur, causing unevenness. In particular, since a relatively large voltage is applied to the gate bus line 15 as described above, the gate bus line 15 contributes greatly to the generation of the above-mentioned spots.

In the liquid crystal display device 800, the recovery electrode 19 has an opening 19a formed to cross the edge of the gate bus line 15, as shown in FIG. 39, and the gate bus line 15. A part of the edge of is not covered by the solid portion 19b of the recovery electrode 19. Therefore, since there is a region not covered with the conductive film (solid portion 19b) of the recovery electrode 19 near the edge of the gate bus line 15, light leakage due to the residual potential in the region does not exist. Occurs, staining occurs on the display.

In contrast, in the liquid crystal display device 500 of the present embodiment, the opening portion 19a of the recovery electrode 19 is formed so as not to cross the edge of the gate bus line 15, and the edge of the gate bus line 15. Is covered with the solid portion 19b of the recovery electrode 19. Therefore, since the influence of the gradient electric field generated near the edge of the gate bus line 18 is electrically shielded (shielded), the liquid crystal molecules 30a of the liquid crystal layer 30 are subjected to the alignment control force by the gradient electric field. There is no inclination. Therefore, generation | occurrence | production of light leakage is suppressed and the fall of contrast ratio is suppressed. In the liquid crystal display device 500, the edge of the gate bus line 15 is covered with the solid portion 19b of the recovery electrode 19, and the area near the edge of the gate bus line 15 is sweeped. Since it is covered with the conductive film (solid part 19b) of the electrode 19, residual electric potential hardly arises and generation | occurrence | production of a stain | stain is suppressed. As described above, in the liquid crystal display device 500, the occurrence of light leakage due to the inclined electric field generated near the gate bus line 15 is suppressed, and the decrease in the contrast ratio is suppressed, and the gate bus line 15 is suppressed. Since generation | occurrence | production of the irregularity resulting from the residual electric potential in the vicinity is suppressed, high quality display is implement | achieved.

In addition, in this embodiment, the case where the edge of the gate bus line 15 is covered with the solid part 19b of the recovery electrode 19 was demonstrated, However, with the liquid crystal display device 500A shown in FIG. Similarly, the edge of the source bus line 16 may be covered with the solid portion 19b of the recovery electrode 19. The display quality can be improved by covering at least one edge of the gate bus line 15 and the source bus line 16 with the solid portion 19b of the recovery electrode 19. In general, the gradient electric field generated near the edge of the gate bus line 15 has a greater influence on the liquid crystal molecules than the gradient electric field generated near the edge of the source bus line 16, so that at least the gate bus line 15 It is preferable to cover the edge of the () with the solid portion 19b of the recovery electrode 19. In addition, from the viewpoint of more reliably suppressing the influence of the gradient electric field generated near the edge of the bus line 18, as in the liquid crystal display device 500B shown in FIG. 41, the gate bus line 15 and the source bus line are shown. It is preferable to cover both edges of (16) with the solid portion 19b of the recovery electrode 19.

In the liquid crystal display device according to the present invention, the deterioration of display quality due to the inclined electric field generated near the edge of the bus line is suppressed. Therefore, according to this invention, the liquid crystal display device which has a wide viewing angle characteristic and is high in display quality can be provided.

This invention is used suitably for the active-matrix type liquid crystal display device, and is suitably used also for all the liquid crystal display devices of a transmission type, a reflection type, and a transmission reflection combined use type.

Claims (16)

It has a 1st board | substrate, a 2nd board | substrate, and the liquid crystal layer formed between the said 1st board | substrate and said 2nd board | substrate, and has a several recovery area | region for displaying, The first substrate includes a recovery electrode formed for each of the plurality of recovery regions, a switching element electrically connected to the recovery electrode, a gate bus line and a source bus line electrically connected to the switching element. Has a bus line to include, The said 2nd board | substrate has a counter electrode which opposes the said recovery electrode through the said liquid crystal layer, The said recovery electrode has a solid part which consists of a some opening part and a some unit solid part, In each of the said several recovery area | regions, The liquid crystal layer takes a vertical alignment state when no voltage is applied between the recovery electrode and the counter electrode, and when the voltage is applied between the recovery electrode and the counter electrode, By the inclined electric field generated at the edge portions of the plurality of openings, a plurality of liquid crystal domains each having a radial oblique alignment state are formed in the plurality of openings and the solid portion, and the plurality of liquid crystal domains according to the applied voltage. As a liquid crystal display device which displays by changing the orientation state of In each of the plurality of recovery regions, at least one of the openings adjacent to the bus line and located between two unit solid portions adjacent to the plurality of unit solid portions among the plurality of openings of the recovery electrode, Liquid crystal display that overlaps with the bus line. The method of claim 1, And the at least one opening overlapping the bus line includes at least an opening close to the gate bus line. The method of claim 2, And all of the openings close to the gate bus line of the plurality of openings of the recovery electrode overlap the bus line. The method of claim 2, And the at least one opening overlapping the bus line further includes an opening adjacent to the source bus line. The method of claim 3, And the at least one opening overlapping the bus line further includes an opening adjacent to the source bus line. It has a 1st board | substrate, a 2nd board | substrate, and the liquid crystal layer formed between the said 1st board | substrate and said 2nd board | substrate, and has a several recovery area | region for displaying, The first substrate includes a recovery electrode formed for each of the plurality of recovery regions, a switching element electrically connected to the recovery electrode, a gate bus line and a source bus line electrically connected to the switching element. Has a bus line to include, The said 2nd board | substrate has a counter electrode which opposes the said recovery electrode via the said liquid crystal layer, The collection electrode has a plurality of openings and a solid portion each consisting of a plurality of unit solid portions surrounded by at least some of the openings of the plurality of openings, The liquid crystal layer is a liquid crystal display device having a vertical alignment state when a voltage is applied between the recovery electrode and the counter electrode. In each of the plurality of recovery regions, at least one of the openings adjacent to the bus line and located between two unit solid portions adjacent to the plurality of unit solid portions among the plurality of openings of the recovery electrode, Liquid crystal display that overlaps with the bus line. The method of claim 6, And the at least one opening overlapping the bus line includes at least an opening close to the gate bus line. The method of claim 7, wherein And all of the openings close to the gate bus line of the plurality of openings of the recovery electrode overlap the bus line. The method of claim 7, wherein And the at least one opening overlapping the bus line further includes an opening adjacent to the source bus line. The method of claim 8, And the at least one opening overlapping the bus line further includes an opening adjacent to the source bus line. It has a 1st board | substrate, a 2nd board | substrate, and the liquid crystal layer formed between the said 1st board | substrate and said 2nd board | substrate, and has a several recovery area | region for displaying, The first substrate includes a recovery electrode formed for each of the plurality of recovery regions, a switching element electrically connected to the recovery electrode, a gate bus line and a source bus line electrically connected to the switching element. Has a bus line to include, The said 2nd board | substrate has a counter electrode which opposes the said recovery electrode via the said liquid crystal layer, The recovery electrode has a plurality of openings and a solid portion, In each of the plurality of recovery regions, the liquid crystal layer takes a vertical alignment state when no voltage is applied between the recovery electrode and the counter electrode, and a voltage is applied between the recovery electrode and the counter electrode. A liquid crystal display device whose orientation is regulated by a gradient electric field generated at edge portions of the plurality of openings of the recovery electrode when In each of the plurality of recovery regions, at least one edge of the gate bus line and the source bus line is covered by the solid portion of the recovery electrode. The method of claim 11, In each of the plurality of recovery regions, at least an edge of the gate bus line is covered by the solid portion of the recovery electrode. The method of claim 11, The solid portion of the recovery electrode is composed of a plurality of unit solid portions, In each of the plurality of recovery regions, the liquid crystal layer is formed by a gradient electric field generated at edge portions of the plurality of openings of the recovery electrode when a voltage is applied between the recovery electrode and the counter electrode. And a plurality of liquid crystal domains each having a radial oblique alignment state in the opening and the solid portion, and displaying by changing the alignment state of the plurality of liquid crystal domains according to an applied voltage. The method of claim 12, The solid portion of the recovery electrode is composed of a plurality of unit solid portions, In each of the plurality of recovery regions, the liquid crystal layer is formed by a gradient electric field generated at edge portions of the plurality of openings of the recovery electrode when a voltage is applied between the recovery electrode and the counter electrode. And a plurality of liquid crystal domains each having a radial oblique alignment state, in the opening portion and the solid portion, and displaying by changing the alignment state of the plurality of liquid crystal domains according to an applied voltage. The method of claim 13, In each of the plurality of recovery regions, at least one of the openings adjacent to the bus line and located between two unit solid portions adjacent to the plurality of unit solid portions among the plurality of openings of the recovery electrode, Liquid crystal display that overlaps with the bus line. The method of claim 13, The liquid crystal layer forms a portion of the liquid crystal domain in which a radial inclination alignment state is formed in the solid portion proximate to the bus line by the gradient electric field when a voltage is applied between the recovery electrode and the counter electrode. Liquid crystal display.