KR100507586B1 - Liquid crystal display device - Google Patents

Abstract

A liquid crystal display device including a first electrode and a plurality of recovery regions respectively defined by a second electrode opposing the first electrode via a liquid crystal layer is provided. The first electrode has a plurality of unit solid portions disposed along the first direction in each of the recovery regions, and the liquid crystal layer takes a vertical alignment state when no voltage is applied, and further, in response to the voltage being applied, the unit An inclined electric field generated around the solid part forms a liquid crystal domain having a radial oblique alignment state in each unit solid part. The plurality of recovery regions are arranged in a matrix shape consisting of a plurality of rows extending in a second direction different from the first direction and a plurality of columns extending along the first direction, and within each frame, along the second direction. Adjacent elements are driven with opposite polarities.

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 device used for a display of a personal computer or a personal digital assistance (PDA) display unit, a thin, lightweight liquid crystal display device has been used. However, the conventional twisted nematic type (TN type) and super twisted nematic type (STN type) liquid crystal display devices have drawbacks with a narrow viewing angle. Various technical developments are performed to solve it.

As a representative technique for improving the viewing angle characteristic of a TN type or STN type liquid crystal display, there is a method of adding an optical compensation plate. Another method 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. This transverse electric field type liquid crystal display device has recently been mass produced 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 a voltage controlled birefringence (ECB) method to control the transmittance using the birefringence of the liquid crystal molecules.

However, the transverse electric field system is one of the effective methods for improving the viewing angle. However, in the manufacturing process, the production margin is significantly lower than that of a normal TN type device, and thus there is a problem that stable production is difficult. This is because gap unevenness between substrates and shifts in the transmission axis (polarization axis) direction of the polarizing plate relative to the alignment axis of the liquid crystal molecules greatly affect the display brightness and contrast ratio. In order to perform stable production by controlling these elements with high precision, further technical development is required.

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

Therefore, some of the inventors of the present application are a method of performing orientation control without performing a rubbing process together with another person, wherein one of a pair of electrodes facing each other via a liquid crystal layer is provided with a lower electrode, an upper layer electrode having an opening, and these As a two-layer structure electrode composed of a dielectric layer formed therebetween, a method of controlling the orientation direction of liquid crystal molecules by a gradient electric field generated at the edge portion of an opening of an upper electrode has been proposed (for example, Japanese Patent Laid-Open No. 2002-55343). Publication). According to this method, an alignment state in which the continuity of the alignment of the liquid crystal molecules is sufficiently stable can be obtained over the whole of the picture element, thereby improving the viewing angle and displaying high quality.

However, in recent years, not only wide viewing angles and high display quality, but also higher high aperture ratios for brighter displays are required for liquid crystal displays. There is no specific technique for further improving the aperture ratio in the case of performing orientation regulation using a gradient electric field.

This invention is made | formed in order to solve the said problem, and an object of this invention is to provide the liquid crystal display device which has a wide viewing angle characteristic, is high in display quality, and can display bright with an aperture ratio.

The liquid crystal display device which concerns on this invention has the 1st board | substrate, the 2nd board | substrate, and the liquid crystal layer formed between the said 1st board | substrate and the said 2nd board | substrate, The 1st formed in proximity to the said liquid crystal layer of the said 1st board | substrate. In each of the said several recovery area | region, it has a some recovery area | region each defined by an electrode and the 2nd electrode formed in the said 2nd board | substrate and opposing said 1st electrode via the said liquid crystal layer, The first electrode has a plurality of unit solid portions disposed along a first direction, and the liquid crystal layer takes a vertical alignment state when no voltage is applied between the first electrode and the second electrode, When a voltage is applied between the first electrode and the second electrode, each of the plurality of unit solid portions is radially inclined by a gradient electric field generated around the plurality of unit solid portions of the first electrode. Taking orientation A liquid crystal display device for forming a liquid crystal domain of the can,

The plurality of recovery areas are arranged in a matrix form consisting of a plurality of rows along a second direction different from the first direction and a plurality of columns along the first direction, and within the one frame, the plurality of recovery areas. The polarity of the voltage applied to the liquid crystal layer in any of the first recovery regions of is applied to the liquid crystal layer in the second recovery region belonging to the same row as the first recovery region and belonging to a column adjacent to the first recovery region. It has a configuration different from the polarity of the voltage, whereby the above object is achieved.

In a preferred embodiment, the plurality of recovery regions may have a shape in which a longitudinal direction is defined along the first direction, and a width direction is defined along the second direction.

In a preferred embodiment, the polarity of the voltage applied to the liquid crystal layer in the plurality of recovery regions belonging to any one column of the plurality of recovery regions is inverted every n rows (n is an integer of 1 or more).

In a preferred embodiment, the polarity of the voltage applied to the liquid crystal layer in the first recovery region belongs to the same column as the first recovery region, and the liquid crystal in the third recovery region belongs to a row adjacent to the first recovery region. You may have a structure different from the polarity of the voltage applied to a layer.

In a preferred embodiment, each of the plurality of unit solid portion has a rotational symmetry. For example, each of the plurality of unit solid portions may be substantially circular, and each of the plurality of unit solid portions may have a substantially rectangular shape having a substantially arcuate shape. Alternatively, each of the plurality of unit solid portions may have a shape in which each portion is sharpened.

In a preferred embodiment, the second substrate has an alignment regulating force for radially inclining the liquid crystal molecules in the at least one liquid crystal domain in at least a voltage applied state to a region corresponding to at least one liquid crystal domain among the plurality of liquid crystal domains. You may have the orientation regulation structure which generate | occur | produces.

In a preferred embodiment, the alignment regulating structure is formed in a region corresponding to each of the plurality of liquid crystal domains.

In a preferred embodiment, the alignment regulating structure is preferably formed in a region corresponding to the center of the at least one liquid crystal domain.

In a preferred embodiment, the orientation regulating direction by the alignment regulating structure in the at least one liquid crystal domain is determined by the direction of the radial inclined alignment due to the gradient electric field generated around the plurality of unit solid portions of the first electrode. It is desirable to match.

In a preferred embodiment, the alignment regulating structure may be configured to generate an alignment regulating force for radially inclining the liquid crystal molecules even in a voltage-free state. For example, the orientation regulating structure may be a first convex portion protruding toward the liquid crystal layer side of the second substrate, and the first convex portion protruding toward the liquid crystal layer side of the second substrate may be used for the liquid crystal layer. The thickness may be defined. In a preferred embodiment, the first convex portion preferably has a side that forms an angle of less than 90 ° with the substrate surface of the second substrate. Alternatively, the alignment regulating structure may be configured to include a horizontally oriented surface formed on the liquid crystal layer side of the second substrate.

In a preferred embodiment, the alignment regulating structure may be configured to generate an alignment regulating force for radial oblique alignment of liquid crystal molecules only in a voltage application state. For example, the orientation regulating structure may be configured to include an opening formed in the second electrode.

In a preferred embodiment, the first substrate has a plurality of opening regions which do not overlap the first electrode, and the liquid crystal layer is inclined when a voltage is applied between the first electrode and the second electrode. By the electric field, a plurality of liquid crystal domains each having a radial oblique alignment state are further formed in the plurality of opening regions.

In a preferred embodiment, the opening regions of at least some of the plurality of opening regions form a plurality of unit grids having substantially the same shape and the same size and arranged to have rotational symmetry. Preferably, each shape of the at least part of the opening regions of the plurality of opening regions has rotational symmetry.

In a preferred embodiment, each of the at least part of the opening regions of the plurality of opening regions may have a substantially circular configuration.

In a preferred embodiment, a second convex portion is further provided inside each of the plurality of opening regions of the first substrate, and the side surface of the second convex portion is formed by the gradient electric field with respect to the liquid crystal molecules of the liquid crystal layer. You may comprise so that it may have an orientation regulation force of the same direction as an orientation regulation direction.

In a preferred embodiment, the first substrate further has a switching element formed corresponding to each of the plurality of recovery regions, wherein the first electrode is formed for each of the plurality of recovery regions and is switched by the switching element. The second electrode may be configured to be at least one counter electrode facing the plurality of recovery electrodes. The counter electrode is typically formed as a single electrode over the entire display area.

The operation of the present invention will be described below.

In the liquid crystal display device of the present invention, one of the pair of electrodes for applying a voltage to the liquid crystal layer in the recovery region has a plurality of unit solid portions disposed along a predetermined direction (hereinafter referred to as "first direction"). have. The liquid crystal layer takes a vertical alignment state in a state where no voltage is applied, and in the voltage application state, a plurality of liquid crystal domains that take a radial oblique alignment state by a gradient electric field generated around the plurality of unit solid portions of the electrode. Form. Then, when the voltage is applied between the pair of electrodes, the external shape of one electrode is defined to generate a gradient electric field around the plurality of unit solid portions to form a plurality of liquid crystal domains having a radial gradient orientation. The liquid crystal layer is typically made of a liquid crystal material having negative dielectric anisotropy, and is regulated by a vertical alignment film formed on both sides thereof.

The liquid crystal domain formed by this gradient electric field is formed in the area | region corresponding to a unit solid part, and displays by making the orientation state of a liquid crystal domain change with voltage. Since each liquid crystal domain takes a radial oblique orientation and an axisymmetric orientation, the visual dependence of the display quality is small and has a wide visual characteristic.

Here, the part in which an electrically conductive film exists among an electrode is called "solid part", and the part which produces the electric field which forms one liquid crystal domain in a solid part is called "unit solid part." The solid portion is typically formed of a continuous conductive film.

Further, in each of the recovery areas, the plurality of unit solid parts are arranged along a predetermined direction and arranged (in one row), so that the unit solid parts in the recovery area are arranged in two or more rows. The opening ratio can be improved by increasing the area ratio.

The plurality of recovery regions are arranged in a matrix form consisting of a plurality of rows along a second direction different from the first direction described above and a plurality of columns along the first direction. In the liquid crystal display device according to the present invention, the polarity of the voltage applied to the liquid crystal layer in any first element in the plurality of element regions is in the same row as the first element in each frame, It is different from the polarity of the voltage applied to the liquid crystal layer in the second cycle belonging to the adjacent column. That is, within the period (1 frame) in which writing is performed in all the elements, the elements adjacent to each other in the row direction (second direction) are reversely driven.

Accordingly, it is possible to generate a gradient electric field having a sharp electric potential gradient between the elements adjacent in the row direction as compared with the case where the elements adjacent in the row direction are not inverted. Therefore, even if the structure where the interelectrode distance of the elements adjacent in a row direction is short and a high aperture ratio is employ | adopted, a sufficiently stable radial oblique orientation can be formed.

Typically, the recovery region has a shape in which the longitudinal direction is defined along the first direction (arrangement direction of the unit solid portion) and the width direction is defined along the second direction. If the recovery region has such a shape, the aperture ratio can be effectively improved. The recovery area is, for example, substantially rectangular with a long side along the first direction and a short side along the second direction.

Inverting the adjacent pixels along the row direction in one frame and inverting the pixels along the column direction every n (n is an integer of 1 or more), i.e., belongs to any one column of the plurality of recovery areas. If the polarity of the voltage applied to the liquid crystal layer in the plurality of recovery regions is inverted every n (n is an integer of 1 or more), flicker can be suppressed.

In particular, when the driving is inverted in each row along the column direction, that is, the polarity of the voltage applied to the liquid crystal layer in any first recovery area among the plurality of recovery areas is in the same column as the first recovery area in each frame. Belonging to a row adjacent to the first recovery area, and if the polarity of the voltage applied to the liquid crystal layer is different from the polarity of the voltage applied to the liquid crystal layer, a gradient electric field having a sharp electric potential gradient can be generated even between the pixels adjacent to the column direction. Therefore, the distance between electrodes of adjacent elements can be shortened, and the aperture ratio can be further improved.

Each of the plurality of unit solid portions preferably has rotational symmetry. When the shape of the unit solid portion has rotational symmetry, the radial oblique orientation of the liquid crystal domain to be formed also becomes an orientation having rotational symmetry, that is, an axisymmetric orientation, and the visual characteristic is improved.

When each of the plurality of unit solid portions is approximately circular or approximately elliptical, the continuity of the alignment of the liquid crystal molecules in the radial oblique alignment state is increased, so that the orientation stability is improved.

On the other hand, if each of the plurality of unit solid portions is substantially spherical, the area ratio (effective aperture ratio) of the unit solid portion in the recovery region becomes high, and thus optical characteristics (for example, transmittance) with respect to the voltage applied to the liquid crystal layer. This improves.

In addition, if each of the plurality of unit solid portions is an approximately spherical shape in which each portion is approximately arc-shaped, both the orientation stability and the optical characteristics can be enhanced.

In addition, when each of the plurality of unit solid portions has an angled shape, the total length of the electrode generating the gradient electric field increases, so that the gradient electric field can be applied to more liquid crystal molecules. As a result, the response speed is improved.

The other substrate (that is, the substrate facing the substrate including the electrode having the unit solid portion) has at least a voltage across the liquid crystal molecules in the at least one liquid crystal domain in a region corresponding to at least one liquid crystal domain among the plurality of liquid crystal domains. It has an orientation regulation structure which produces the orientation regulation force which makes radial oblique orientation in the applied state. Then, at least in the voltage application state, since the alignment regulating force by the electrode having the unit solid portion and the alignment regulating force by the alignment regulating structure act on the liquid crystal molecules in the liquid crystal domain, the radial oblique alignment of the liquid crystal domain is more stabilized, Reduction of display quality (for example, generation of afterimages) by stress application to the layer is suppressed.

When the alignment regulation structure is formed in a region corresponding to each of the plurality of liquid crystal domains, the radial oblique alignment of all the liquid crystal domains can be stabilized.

By forming the alignment regulating structure in an area corresponding to the vicinity of the center of the liquid crystal domain taking the radial oblique alignment formed by the alignment regulating structure, the position of the central axis of the radial oblique alignment can be fixed, so that Tolerance effectively improves.

Matching the orientation regulation direction by the orientation regulation structure with the direction of the radial gradient orientation by the gradient electric field generated around each of the unit solid portions increases the continuity and stability of the orientation and improves the display quality and response characteristics.

The orientation regulating structure can attain the effect of stabilizing the orientation at least when the orientation regulation force is exerted in the voltage application state, but the orientation regulation structure can be stabilized irrespective of the magnitude of the applied voltage by adopting a configuration that exerts the orientation regulation force even in the absence of voltage. Advantage is obtained. However, since the liquid crystal molecules of the vertical alignment type in which the liquid crystal molecules are oriented substantially perpendicular to the substrate surface in the voltage-free state are used, the display quality deteriorates when an alignment regulating structure expressing the alignment regulating force is used even in the voltage-free state. Will accompany. However, as will be described later, the orientation regulating force of the orientation regulating structure exerts an effect even if it is relatively weak. Therefore, even if the structure is small compared to the size of the sweep, the orientation can be sufficiently stabilized. In such a small structure, the deterioration of the display quality when no voltage is applied may not be a practical problem. Depending on the use of the liquid crystal display device (for example, the magnitude of the stress applied from the outside) or the configuration of the electrode (the strength of the alignment control force by the electrode having the unit solid portion), the alignment control structure generates a relatively strong alignment control force. Is provided. In such a case, in order to suppress the fall of the display quality by an orientation regulation structure, you may form a light shielding layer. Since the orientation regulation structure may only generate the orientation regulation force weaker than the orientation regulation force by the electrode which has a unit solid part, it can implement | achieve using various structures.

The orientation regulating structure formed on the other substrate may be, for example, a convex portion protruding from the second substrate toward the liquid crystal layer side, or may include a horizontally oriented surface formed near the liquid crystal layer side on one side of the substrate. Alternatively, the orientation regulating structure may be an opening formed in the electrode. These can be manufactured by a well-known method.

The board | substrate with an electrode which has a unit solid part typically has some opening area | region which does not overlap with an electrode (the conductive film of an electrode is not formed in the opening part). The liquid crystal display of this invention may employ | adopt the structure in which the liquid crystal domain which takes a radial oblique alignment state is formed also in this opening area.

Since the liquid crystal domain formed in the opening region and the liquid crystal domain formed in the unit solid portion are formed by a gradient electric field generated at the edge portion (periphery of the unit solid portion) of the opening region, they are alternately formed adjacent to each other, In addition, the orientation of liquid crystal molecules between adjacent liquid crystal domains is essentially continuous. Therefore, a disclination line is not generated between the liquid crystal domain formed in the opening region and the liquid crystal domain formed in the unit solid portion, and thus there is no deterioration in display quality and high stability of the alignment of the liquid crystal molecules.

When the liquid crystal molecules adopt radial oblique alignment not only in the region corresponding to the unit solid portion of the electrode, but also in the region corresponding to the opening region, a high degree of continuity in the alignment of the liquid crystal molecules and a stable alignment state are realized, thereby providing a non-coarse uniform display. 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 the liquid crystal molecules act on many liquid crystal molecules, and for that purpose, the opening region (total length of the edge portion) is greatly increased. Need to be formed. When a liquid crystal domain having a stable radial oblique alignment is formed corresponding to the opening area, even if a large number of the opening areas are formed to improve the response characteristics, the deterioration of the display quality (the occurrence of roughness) accompanying it can be suppressed.

At least a part of the plurality of opening regions has a configuration in which at least one unit grid is formed to have substantially the same size and have a rotational symmetry in the same shape, so that the plurality of opening regions are formed in units of unit grids. Since the liquid crystal domain can be arranged with high symmetry, the visual dependence of the display quality can be improved.

Stability of the radial inclination orientation of the liquid crystal domain formed in the opening region can be enhanced by making each shape of the opening region (typically, the opening forming the unit grid) of the plurality of opening regions into a shape having rotational symmetry. have. For example, the shape (shape when viewed from the substrate normal line direction) of each opening area is made circular or polygonal (for example, square). Moreover, you may make it shapes, such as a shape (for example, an ellipse), which do not have rotational symmetry, etc. according to the shape (aspect ratio) of the element.

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

As described above, when the liquid crystal domain is formed in both of the opening region and the unit solid portion, by forming an alignment regulating structure on the other substrate corresponding to each of the formed liquid crystal domains, the radial inclination alignment of all the liquid crystal domains is stabilized. However, even if the alignment regulation structure is formed only for the liquid crystal domain formed corresponding to the unit solid portion, practically sufficient stability (stress resistance) can be obtained.

In particular, the orientation regulating structure which generates the orientation regulating force is a simpler process than the orientation regulating structure which generates the orientation regulating force such that matching with the radial inclination orientation formed in the unit solid portion of the electrode matches the radial inclination orientation formed in the opening region. Since it can form, it is preferable from a viewpoint of production efficiency. At this time, it is preferable to form the alignment regulating structure corresponding to all the unit solid portions, but depending on the electrode structure (the number and arrangement of the unit solid portions), it is only necessary to form some of the unit solid portions, Sufficient orientation stability can be obtained. This is because the radial oblique alignment formed in the liquid crystal layer of the liquid crystal display device of the present invention is essentially continuous.

Moreover, in order to improve resistance to stress, even if the convex part provided with the side surface which has the orientation control force in the same direction as the orientation regulation direction by the above-mentioned inclination electric field with respect to the liquid crystal molecule of a liquid crystal layer is formed inside an opening area | region, do. 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 area | region, and it is preferable to have rotation symmetry similarly to the shape of the opening area mentioned above. However, since the liquid crystal molecules whose orientation is regulated by the orientation regulating force on the side surfaces of the convex portions are difficult to respond to the voltage (because the change in the retardation of the liquid crystal molecules is small in response to the applied voltage), the contrast ratio of the display is lowered. It becomes a factor. Therefore, it is preferable to set the size, height, or number of the convex portions so as not to degrade the display quality.

The liquid crystal display device according to the present invention is, for example, an active matrix liquid crystal display device including switching elements such as TFTs for each of the recovery regions. The electrode which has the opening part mentioned above is a recovery electrode connected to the switching element, and the other electrode is at least 1 opposing electrode which opposes a some recovery electrode.

<Embodiment>

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described with reference to drawings.

First embodiment

First, the electrode structure of the liquid crystal display device of this invention and its effect are demonstrated. Since the liquid crystal display device which concerns on this invention has the outstanding display characteristic, it is used suitably for an active-matrix type liquid crystal display device. EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described about the active-matrix liquid crystal display device using a thin film transistor (TFT). The present invention is not limited to this and can be applied to an active matrix liquid crystal display device using a MIM structure. In addition, although embodiment of this invention is described about a transmissive liquid crystal display device below, this invention is not limited to this, It is applicable to a reflection type liquid crystal display device and the transmissive reflection liquid crystal display device mentioned later further.

In addition, in this specification, the area | region of the liquid crystal display device corresponding to "picture element" 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 simple matrix liquid crystal display, each region where the column electrodes formed in the stripe shape and the row electrodes formed to be orthogonal to the column electrodes cross each other defines a recovery region. In the configuration in which the black matrix is formed, strictly, a 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 structures of three recovery regions P1, P2, and P3 of the liquid crystal display device 100 of the first 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 plan view seen from a substrate normal line direction, and FIG. 1B corresponds to a cross-sectional view along the line 1B-1B ′ of 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 called 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 as a vertical alignment layer formed on one surface of each of the TFT substrate 100a and the opposing substrate 100b proximate the liquid crystal layer 30 side. When no voltage is applied to the liquid crystal layer 30 by the alignment film (not shown), as shown in FIG. 1B, the alignment film is vertically aligned with respect to the surface of the vertical alignment film. 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. In general, a state in which the liquid crystal molecular axis (also referred to as "axial orientation") is oriented at an angle of about 85 degrees 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. The alignment state of the liquid crystal layer 30 for each of the recovery regions changes in accordance with the voltage applied to the recovery electrode 14 and the counter electrode 22 arranged to face each other via the liquid crystal layer 30. With the change of the orientation state of the liquid crystal layer 30, display is performed using the phenomenon in which the polarization state and quantity of the light which permeate the liquid crystal layer 30 change.

The TFT substrate 100a has a plurality of opening regions 15 that do not overlap the recovery electrode 14 formed of a conductive film (for example, an ITO film) (the recovery electrode 14 is not formed). .

The plurality of opening regions 15 are arranged such that the center thereof forms a square lattice, and the portion 14a of the sweep electrode 14 has four centers positioned on four lattice points forming one unit grid. Substantially surrounded by two opening regions 15. A portion 14a of the recovery electrode 14 surrounded by the plurality of opening regions 15 is referred to as a "unit solid portion". The solid part (part in which the conductive film exists) of the collection electrode 14 is comprised by the some unit solid part 14a. In other words, the recovery electrode 14 is composed of a plurality of unit solid portions 14a serving as sub-recovery electrodes. The plurality of unit solid portions 14a are basically formed from a single continuous conductive film.

The plurality of recovery regions are arranged in a matrix shape. Therefore, the plurality of recovery regions are periodically arranged in the row direction and the column direction crossing them. The row direction and the column direction are called "cycle direction" of the sweep (recovery area). Typically, the row and column directions are orthogonal to each other. In addition, in this embodiment, since each recovery area | region (recovery) has a substantially rectangular shape which has a long side and a short side, each period (called "recovery pitch") in a row direction and a column direction Are different.

In one recovery area, the plurality of unit solid portions 14a included in the recovery electrode 14 are arranged in one line along one of the periodic directions. Here, the plurality of unit solid portions 14a are arranged along the column direction D1 as shown in FIG. 1A, and in FIG. 1A, three firing regions P1, P2, and P3 adjacent along the row direction D2 are illustrated. have.

Here, the unit solid portion 14a has a substantially circular shape. In addition, each of the plurality of opening regions 15 has an approximately star shape having four quarter arc-shaped edges (edges) and four rotation axes in the center of the four sides. Each opening region 15 is typically continuous with at least one opening region 15 of a plurality of adjacent opening regions 15.

The plurality of opening regions 15 have the same size in substantially the same shape. The unit solid portion 14a located in the unit grid formed by the opening region 15 is substantially circular. The unit central portion 14a has substantially the same shape and has the same size. The unit solid portions 14a which are adjacent to each other in one recovery region are interconnected and constitute a solid portion (recovery electrode 14) 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, it is generated in the periphery of the unit solid portion 14a (near the outer periphery), that is, at the edge portion of the opening region 15. By the inclined electric field, a plurality of liquid crystal domains each having a radial oblique alignment are formed. One liquid crystal domain is formed in each region corresponding to each of the opening regions 15 and one region corresponding to the unit solid portion 14a.

In this embodiment, as shown in Fig. 2, within the period (one frame) in which data writing is performed in all the elements, the adjacent elements are inverted and driven along the row direction D2. In FIG. 2, a voltage of (inverse) polarity different from the voltage applied to the liquid crystal layer of the recovery region P2 in which (+ is indicated) is applied to the liquid crystal layer 30 of the recovery regions P1 and P3 in which + is indicated. That is, in each frame, the polarity of the voltage applied to the liquid crystal layer 30 in one recovery region is along the direction (row direction D2) orthogonal to the arrangement direction (column direction D1) of the unit solid portion 14a. The polarity of the voltage applied to the liquid crystal layer 30 is different in another recovery area adjacent to the first recovery area.

The mechanism by which the liquid crystal domain is formed by the gradient electric field described above will be described with reference to FIGS. 3A and 3B. 3A and 3B show a state where a voltage is applied to the liquid crystal layer 30 shown in FIG. 1B, respectively, and FIG. 3A shows that the orientation of the liquid crystal molecules 30a changes according to the voltage applied to the liquid crystal layer 30. The following starting state (initial ON state) is schematically shown, and FIG. 3B 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. Curved EQ in Figures 3a and 3b means equipotential lines.

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. 1B, the liquid crystal molecules 30a in the recovery region It is oriented 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. 3A is formed. This equipotential line EQ is formed on the surface of the unit solid portion 14a and the counter electrode 22 in the liquid crystal layer 30 positioned between the unit solid portion 14a of the recovery electrode 14 and the counter electrode 22. Parallel to, and dropped to an area corresponding to the opening area 15 of the recovery electrode 14. In the liquid crystal layer 30 on the edge portion of the opening region 15 (inside and around the opening region 15 including the boundary (outer edge) of the opening region 15) EG, it is indicated by an inclined equipotential line EQ. An inclined electric field is formed. In addition, in this embodiment, since the two mutually adjacent elements along the row direction D2 are driven with opposing polarity voltages, the equipotential line EQ drops rapidly in the opening region 15 located between these elements, so that The equipotential EQs formed are not continuous with each other.

The liquid crystal molecules 30a having negative dielectric anisotropy act to align the axial orientation of the liquid crystal molecules 30a in parallel with the equipotential lines EQ (vertical to the electric field lines). Accordingly, the liquid crystal molecules 30a of FIG. 3A on the right edge portion EG are inclined clockwise (rotate), as shown by the arrows of FIG. 3A, and are inclined (rotate) counterclockwise in the left edge portion EG. Lose. As a result, the liquid crystal molecules 30a on the edge portion WG are oriented parallel to the corresponding portions of the equipotential line EQ.

Here, with reference to FIGS. 4A-4D, the orientation change 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 to orient their axial orientation in parallel to the equipotential line EQ. As shown in FIG. 4A, when an electric field represented by an equipotential line EQ perpendicular to the axial orientation of the liquid crystal molecules 30a is generated, the liquid crystal molecules 30a have the same torque for inclination in the clockwise or counterclockwise direction. Acts as a ratio. Therefore, in the liquid crystal layer 30 between the electrodes of the parallel flat plate arrangement | positioning which mutually opposes, 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 of the orientation state according to the voltage applied to the liquid crystal layer 30 may not occur smoothly.

As shown in FIG. 3A, in the edge portion EG of the opening region 15 of the liquid crystal display device 100 according to the present invention, an electric field represented by an equipotential line EQ inclined with respect to the axial orientation of the liquid crystal molecules 30a ( 4B, the liquid crystal molecules 30a are inclined in a direction (anticlockwise rotation in the illustrated example) with a small amount of inclination for paralleling the equipotential lines EQ. In addition, 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 generated as shown in FIG. 4C. 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 region is continuous (matched). As shown in Fig. 4D, when an electric field in which the equipotential line EQ forms an uneven shape is applied, the flat equipotential is matched with the orientation direction regulated by the liquid crystal molecules 30a positioned on each inclined equipotential line EQ. Liquid crystal molecules 30a positioned on the line EQ are oriented. Here, the expression "located on the equipotential line EQ" means "located in the electric field represented by the equipotential line EQ".

As described above, when the change in the orientation starting from the liquid crystal molecules 30a positioned on the inclined equipotential line EQ proceeds to reach a steady state, the alignment state schematically shown in FIG. 3B is obtained. Since the liquid crystal molecules 30a positioned near the center of the opening region 15 are almost equally affected by the orientation of the liquid crystal molecules 30a of the edge portions EG on both sides of the opening region 15 facing each other, the equipotential is Maintain an orientation perpendicular to the line EQ. The liquid crystal molecules 30a in the region deviating from the center of the opening region 15 are inclined under the influence of the alignment of the liquid crystal molecules 30a of the edge portion EG near each other, and are symmetrical with respect to the center SA of the opening region 15. To form an oblique orientation. In this alignment state, when viewed from the direction perpendicular to the display surface of the liquid crystal display device 100 (the direction perpendicular to the surfaces of the substrates 11 and 21), the axial orientation of the liquid crystal molecules 30a is determined by the opening region 15. It is in the state oriented radially with respect to the center (not shown). Therefore, in this specification, this alignment state is referred to as "radial oblique alignment". In addition, the area | region of the liquid crystal layer 30 which has radial oblique orientation with respect to one axis is called a liquid crystal domain.

Even in a region corresponding to the unit solid portion 14a substantially surrounded by the opening region 15, 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 14a are affected by the orientation of the liquid crystal molecules 30a in the edge portion EG of the opening region 15, and thus the center SA ( Radial oblique orientation is symmetrical with respect to the center of the unit lattice formed by the opening region 15).

The radial oblique alignment in the liquid crystal domain formed in the unit solid portion 14a and the radial oblique alignment formed in the opening region 15 are continuous, and both of the liquid crystal molecules 30a of the edge portion EG of the opening region 15 are continuous. It is oriented to match the orientation. The liquid crystal molecules 30a in the liquid crystal domain formed in the opening region 15 are aligned in a cone shape in which the upper side (the substrate 100b side) is open, and the liquid crystal molecules 30a in the liquid crystal domain formed in the unit solid portion 14a. Is oriented in a cone shape in which the lower side (substrate 100a side) is open. In this way, the radial inclination orientations formed in the liquid crystal domain formed in the opening region 15 and the liquid crystal domain formed in the unit solid portion 14a are continuous to each other. Therefore, the disclination lines (orientation defects) are not formed at these boundaries, whereby the degradation of display quality due to the generation of the disclination lines does not occur.

Moreover, sufficient voltage is not applied to the liquid crystal layer 30 near the center of the opening area 15, and the liquid crystal layer 30 near the center of the opening area 15 may not contribute to display. That is, even if the radial oblique orientation of the liquid crystal layer 30 near the center of the opening region 15 is slightly disturbed (for example, even if the central axis is out of the center of the opening region 15), the display quality does not decrease. It may not. As a result, when the liquid crystal domain is formed at least in correspondence with the unit solid portion 14a, the continuity of the liquid crystal molecules in the recovery region is obtained, so that the optical viewing characteristics and the high display quality can be obtained.

In order to improve the visual dependence of the display quality of the liquid crystal display device in all directions, it is preferable that the existence probability of liquid crystal molecules oriented along each of all azimuthal directions in each combustion region has rotational symmetry, and axial symmetry It is more preferable to have. Therefore, it is preferable to arrange | position a liquid crystal domain so that it may have high symmetry in a recovery area | region. In the present embodiment, the plurality of unit solid portions 14a are arranged in a line along a predetermined direction (column direction D1), and are arranged to have rotational symmetry and further axial symmetry. Therefore, the liquid crystal domain formed corresponding to the unit solid portion 14a is also arranged to have rotational symmetry, and moreover, axial symmetry.

As described with reference to FIGS. 3A and 3B, the recovery electrode 14 of the liquid crystal display device 100 according to the present invention has a plurality of unit solid portions 14a surrounded by a plurality of opening regions 15. In the liquid crystal layer 30 in the recovery region, an electric field represented by an equipotential line EQ having an inclined region is formed. 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. Change direction. Thus, a liquid crystal domain having a stable radial oblique alignment is formed in the opening region 15 and the unit solid portion 14a. The display is performed by changing the orientation of liquid crystal molecules in this liquid crystal domain in accordance with the voltage applied to the liquid crystal layer.

The shape of the unit solid portion 14a of the recovery electrode 14 of the liquid crystal display device 100 of the present embodiment (the shape seen from the substrate normal direction) and its arrangement, and the TFT substrate 100a of the liquid crystal display device 100. The shape of the opening area | region 15 which has) 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 oriented 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.

Thus, the unit solid portion 14a has a shape such that the liquid crystal domains are formed such that the liquid crystal molecules 30a of the liquid crystal domain formed corresponding to the unit solid portion 14a are aligned with equal probability with respect to all azimuth angles. It is preferable. Specifically, it is preferable that the shape of the unit solid portion 14a has rotational symmetry (preferably symmetry of two or more rotation axes) with each center (normal direction) as the symmetry axis.

In addition, since only a part of the liquid crystal domain formed corresponding to the opening region 15 is included in the recovery region and contributes to the display, the sum of the segments (segments) included in the recovery region of the liquid crystal domain is added to the set of segments. It is preferable that the liquid crystal molecules contained are oriented with equal probability with respect to all azimuth angles. That is, it is preferable to set the shape and arrangement of the opening region 15 so that the segments of the liquid crystal domain complementarily form the liquid crystal domain. Specifically, the shape of the opening region 15 preferably has rotational symmetry, and the opening region 15 is preferably arranged to have rotational symmetry. In addition, since the liquid crystal domain formed in the opening region 15 also has a portion located outside the recovery region, the opening region 15 is strictly arranged so that the segments of the liquid crystal domain complementarily form the liquid crystal domain. Sometimes it is difficult. Nevertheless, in the set of segments of the liquid crystal domain, if the existence probability of liquid crystal molecules oriented along each of all azimuth angles has rotational symmetry (more preferably, axis symmetry), the azimuth dependence of display characteristics is sufficiently reduced. can do.

As shown in FIG. 1A, the alignment state of the liquid crystal molecules 30a when the substantially star-shaped opening regions 15 surrounding the substantially circular unit solid portions 14a are arranged in a square lattice shape is illustrated in FIGS. It demonstrates with reference to 5c.

5A to 5C schematically show the alignment states of the liquid crystal molecules 30a as viewed from the substrate normal 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. 5B and 5C, the end in which the line of the liquid crystal molecule 30a drawn in ellipse shape is displayed in black is more than the other end, It shows that the liquid crystal molecules 30a are inclined so as to be close to the substrate side on which the recovery electrode 14 is formed. The same applies to the following drawings. Here, one unit grid (formed by four opening regions 15) in the recovery region shown in FIG. 1A will be described. Sections along the diagonal lines of Figs. 5A to 5C correspond to Figs. 1B, 3A and 3B, respectively, and will be described with reference to these figures.

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. 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 as shown in FIG. 5A.

When an electric field is applied to the liquid crystal layer 30 and an electric field represented by the equipotential line EQ shown in FIG. 3A is generated, the axial orientation is 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. 4A and 4B, the liquid crystal molecules 30a under the electric field represented by the equipotential line EQ perpendicular to the molecular axis of the liquid crystal molecules 30a have a tilt (rotation) direction of the liquid crystal molecules 30a. Since it is not uniquely determined (FIG. 4A), a change in the orientation (tilt or rotation) does not easily occur. On the other hand, since the inclination (rotation) direction is uniquely determined for the liquid crystal molecules 30a placed under the equipotential line EQ inclined with respect to the molecular axis of the liquid crystal molecules 30a, the change of orientation occurs easily. Therefore, as shown in FIG. 5B, the liquid crystal molecules 30a start to be inclined from the edge portion of the opening region 15 in which the molecular axis of the liquid crystal molecules 30a is inclined with respect to the equipotential line EQ. As described with reference to FIG. 4C, the surrounding liquid crystal molecules 30a are also inclined so as to conform to the alignment and alignment of the inclined liquid crystal molecules 30a of the edge portion of the opening region 15. Then, in the state as shown in Fig. 5C, the axial orientation of the liquid crystal molecules 30a is stabilized (radial oblique alignment).

As described above, when the opening region 15 is shaped to have rotational symmetry, the liquid crystal molecules 30a in the recovery region, when the voltage is applied, form a liquid crystal toward the center of the opening region 15 at the edge of the opening region 15. Molecule 30a is tilted. As a result, the liquid crystal molecules 30a near the center of the center of the opening region 15 in which the alignment regulating force of the liquid crystal molecules 30a from the edge portion is balanced remain vertically aligned with respect to the substrate surface, and the liquid crystal around them A state in which the molecules 30a are continuously inclined radially is obtained in which the inclination angle increases from the center of the opening region 15 with respect to the liquid crystal molecules 30a near the center of the opening region 15.

In addition, the liquid crystal molecules 30a in the region corresponding to the substantially circular unit-solid portion 14a surrounded by four substantially star-shaped opening regions 15 arranged in a square lattice shape also have an edge of the opening region 15. Inclined to match the orientation of the liquid crystal molecules 30a inclined in the oblique electric field generated in the negative. As a result, the liquid crystal molecules 30a near the center of the unit solid portion 14a where the alignment regulating force of the liquid crystal molecules 30a at the edge portions are balanced remain in a state in which the liquid crystal molecules 30a are perpendicularly aligned with respect to the substrate surface. The state in which the liquid crystal molecules 30a are continuously inclined radially continuously about the liquid crystal molecules 30a near the center of the unit solid portion 14a is obtained.

As such, 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 the respective axial directions becomes rotationally symmetrical, and in all visual directions, High quality display without roughness can be realized. 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 two rotation axes or more, more preferably four rotation axes or more).

The radial oblique alignment of the liquid crystal molecules 30a is more stable than the radial oblique alignment as shown in Fig. 6A, as shown in Figs. 6B and 6C, in which the radial oblique alignment around the left or right is more stable. . This spiral orientation differs from the usual twist orientation (the orientation direction of the liquid crystal molecules 30a changes in a spiral shape along the thickness direction of the liquid crystal layer 30). In the spiral orientation, the alignment direction of the liquid crystal molecules 30a hardly changes along the thickness direction of the liquid crystal layer 30 when viewed in the minute region. That is, also in the cross section (cross section in the surface parallel to layer surface) of the position in the thickness direction of the liquid crystal layer 30, as shown in FIG. 6B or 6C, the twist deformation along the thickness direction of the liquid crystal layer 30 is shown. This rarely occurs. However, when looking at the whole liquid crystal domain, some twist distortion generate | occur | produces.

When a material in which a chiral agent is added to a nematic liquid crystal material having negative dielectric anisotropy is used, the liquid crystal molecules 30a are formed in the opening region 15 and the unit solid portion 14a when voltage is applied. The spiral radial oblique orientation in the counterclockwise or clockwise direction, as shown in FIGS. 6B and 6C, is taken. Whether the spiral type is counterclockwise or clockwise depends on the type of chiral agent used. Thus, by spirally orienting the liquid crystal layer 30 in the opening region 15 at the time of voltage application, the liquid crystal molecules 30a of the radially inclined liquid crystal molecules 30a are wound around the liquid crystal molecules 30a standing perpendicular to the substrate surface. Since the direction in which it exists can be made constant in all the liquid crystal domains, uniform display without roughening is attained. 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.

In addition, when a large amount of chiral agent is added, the orientation of the liquid crystal molecules 30a changes in a spiral shape along the thickness direction of the liquid crystal layer 30 as in the usual twist orientation. In the alignment state where 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. Incident light passing through the region in this alignment state, so as not to cause a phase difference with respect to, does not contribute to the transmittance. On the other hand, in the alignment 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 oriented in the vertical direction or in the parallel direction on the polarization axis of the polarizing plate, It is also possible to use the optical rotatory power of the light while causing the phase difference with respect to the incident 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, an example in which the unit solid portion 14a is substantially circular and the star-shaped opening regions 15 are arranged in a square lattice shape is illustrated, but the shape and the opening region 15 of the unit solid portion 14a are illustrated. The shape and arrangement of are not limited to the above examples.

7A and 7B, plan views of the liquid crystal display devices 100A and 100B having different shapes of the opening region 15 and the unit solid portion 14a are shown, respectively.

The opening region 15 and the unit solid portion 14a of the liquid crystal display devices 100A and 100B shown in FIGS. 7A and 7B are respectively the opening region 15 and the unit of the liquid crystal display device 100 shown in FIG. 1A. The solid portion 14a has a slightly deformed form. The opening region 15 and the unit solid portion 14a of the liquid crystal display devices 100A and 100B have two rotational axes (not having four rotational axes) and are regularly arranged to form a rectangular unit grid. . The opening regions 15 all have a distorted star shape, and the unit solid portions 14a all have a substantially elliptical shape (distorted circle). Liquid crystal display devices 100A and 100B shown in FIGS. 7A and 7B also have high display quality and are excellent in visual characteristics.

In addition, the liquid crystal display devices 100C and 100D as shown in Figs. 8A and 8B also have high display quality and are excellent in visual characteristics.

In the liquid crystal display devices 100C and 100D, the opening area 15 of approximately ten crosses is arranged in a square lattice shape so that the unit solid portion 14a becomes substantially square. Of course, you may arrange | position so that these may be distorted and a rectangular unit grid may be formed. Thus, even if the unit solid part 14a of substantially spherical shape (a spherical shape includes a square and a rectangle) is arranged by a correct rule, a display quality is high and a liquid crystal display device excellent in visual characteristics can be obtained.

However, the shape of the opening area 15 and / or the unit solid part 14a is preferable because the circular or elliptical side can stabilize the radial inclination orientation rather than the spherical shape. This is considered to be because the side of the opening region 15 changes continuously (softly), so that the alignment direction of the liquid crystal molecules 30a also changes continuously (softly).

From the viewpoint of the continuity of the alignment direction of the liquid crystal molecules 30a described above, the liquid crystal display device 100E shown in FIG. 9 can also be considered. In the liquid crystal display device 100E shown in FIG. 9, as a modification of the liquid crystal display device 100D shown in FIG. 8B, the unit solid portion 14a side of the opening region 15 is formed by an arc. Although the opening region 15 and the unit solid portion 14a of the liquid crystal display device 100E both have four rotational axes and are arranged in a square grid (having four rotational axes), FIG. 7A And 7b, the shape of the unit solid portion 14a of the opening region 15 may be distorted to form a shape having two rotational axes, so as to form a rectangular lattice (having two rotational axes). .

Since the voltage applied to the liquid crystal domain formed in the opening region 15 is lower than the voltage applied to the liquid crystal domain formed in the unit solid portion 14a, for example, when the display in the normal black mode is performed, the opening region The liquid crystal domain formed at 15 becomes dark. Therefore, it is preferable to make the area ratio of the opening area | region 15 low and to increase the area ratio of the unit solid part 14a in a recovery area | region.

In the liquid crystal display device according to the present invention, since the recovery electrode 14 has a plurality of unit solid portions 14a, the plurality of unit solid portions 14a are suitably disposed in the recovery region according to the shape and size of the recovery region. By arrange | positioning, stable radial inclination orientation state can be implement | achieved in a recovery area, without being restrict | limited by the shape, size, etc. of a recovery area | region. On the other hand, when the recovery electrode is composed of only one unit solid portion, stable radial inclination orientation may not be realized depending on the shape, size, and the like of the recovery region. If the recovery electrode is composed of only one unit solid portion, there is no problem when the recovery area is circular or square. However, for example, when the recovery area is a rectangle having a large aspect ratio, such as a liquid crystal display device capable of color display, the shape of the unit solid portion must be a shape having a large aspect ratio, and stable radial inclination orientation is not realized. It may not. For example, when the size of the recovery region is large, the size of the unit solid portion must be increased, so that a stable orientation may not be obtained only by the inclined electric field formed around the unit solid portion.

In addition, in the liquid crystal display device according to the present invention, as shown in FIG. 1A and the like, the plurality of unit solid portions 14a are arranged (arranged in a line) in a predetermined direction within one combustion region. Compared with the case where two or more columns are arranged, the area ratio of the unit solid portion 14a can be made high, and the ratio (effective opening ratio) of the area contributing to the display in the recovery area can be made high. This reason is explained with reference to FIG.

As shown in FIG. 10, the liquid crystal display device 100E includes a gate bus line (scanning wiring) 41 extending in parallel along the row direction D2 and a source bus line extending in parallel along the column direction D1. Signal wiring) 42. The gate bus line (scan wiring) 41 is electrically connected to the gate electrode of a TFT (not shown) formed in each of the recovery regions, and the source bus line (signal wiring) 42 is electrically connected to the source electrode of the TFT. Connected. In addition, the drain electrode and the recovery electrode 14 of the TFT are electrically connected. The liquid crystal display device 100E further has a storage capacitor wiring 43.

In the liquid crystal display device 100E, since the plurality of unit solid portions 14a are arranged in one row in the recovery region, a part of the opening region 15 surrounding the unit solid portions 14a is formed by the gate bus line 41. ) And the source bus line 42, and are located outside the recovery area. That is, each of the plurality of opening regions 15 is at least partially located outside the recovery region.

On the other hand, when the plurality of unit solid portions 14a are arranged in two or more rows, the opening regions 15 surrounded by the unit solid portions 14a exist in the recovery region, and the opening regions 15 are all Is located in the recovery area. For example, in the liquid crystal display device 1000 of the comparative example in which the unit solid portions 14a are arranged in two rows, as shown in FIG. 11, the opening region 15 surrounded by the unit solid portions 14a in the recovery region. Exists, and this opening area | region 15 is located all in the recovery area | region. Therefore, the area ratio of the opening area | region 15 in a recovery area | region becomes high, and the area ratio of the unit solid part 14a becomes low.

In contrast, as shown in FIG. 10, when the plurality of unit solid portions 14a are arranged in one row in the recovery area, each of the plurality of opening areas 15 is at least partially positioned outside the recovery area. Therefore, by reducing the area ratio of the opening area 15 in the recovery area, the area ratio of the unit solid portion 14a can be increased, and as a result, the opening ratio can be improved.

Here, the improvement of aperture ratio is demonstrated more concretely by taking the liquid crystal display device of arbitrary specifications as an example. The display area has a diagonal of 15 inches, each portion of the unit solid portion 14a has a substantially circular arc shape (a shape shown in FIGS. 9 and 10), a width of a gate bus line and a width of a light shield layer on a source bus line. In this liquid crystal display device having a thickness of 12 μm and a unit solid portion 14a of 8.5 μm, the transmittance is compared when the unit solid portions 14a are arranged in a row and when the unit solid portions 14a are arranged in two rows. It was. When the unit solid sections 14a are arranged in a row, 6% for SXGA (1280 x 1024 pixels), 9% for UXGA (1600 x 1200 pixels), and the unit solid sections 14a for 2 columns. In the case of QXGA (2048 x 1536 pixels), the transmittance of 11% was improved. As described above, the effect of improving the aperture ratio obtained by arranging the plurality of unit solid portions 14a in a line in the recovery area is particularly high in the high-precision liquid crystal display device.

As shown in FIG. 10, in the configuration in which the recovery electrode 14 partially overlaps the gate bus line 41 or the source bus line 42, an insulating film is formed on the bus line in order to reduce the influence from these bus lines. It is preferable to form (for example, an organic insulating film) as thick as possible and to form the recovery electrode 14 thereon.

As shown in FIG. 12, when the length (side spacing on one side) of the interval between the square unit lattice formed by the opening region 15 and the unit solid portion 14a is "S", a stable radial inclination is obtained. In order to generate the gradient electric field required for obtaining the orientation, the one-side space S needs to be at least a predetermined length.

The one-sided space S is defined along the row direction D2 and also along the column direction D1. However, in the present embodiment, as shown in FIG. 2, adjacent neighbors along the row direction D2 are reversed within one frame. Since the driving is performed, sufficient orientation regulating force is obtained even if the one-side space S in the row direction D2 is shortened as compared with the case where the adjacent combustion along the row direction D2 is not inverted. This is because, when the adjacent elements are inverted driven along the row direction D2, a strong gradient electric field can be generated as compared with the case where the inverted drive is not inverted. This reason will be described with reference to FIGS. 13A and 13B.

FIG. 13A schematically shows an equipotential line EQ when a voltage of +5 V is applied to the liquid crystal layers on both adjacent recovery regions along the row direction D2, and FIG. 13B shows two adjacent recovery regions along the row direction D2. The equipotential line EQ when a voltage of + 5V is applied to one liquid crystal layer and -5V to the other liquid crystal layer is schematically shown.

As shown in Fig. 13A, when a voltage having the same polarity is applied to the liquid crystal layers of two adjacent recovery regions, an electric field is formed in which the equipotential line EQ forms a continuous uneven shape.

On the other hand, as shown in Fig. 13B, when voltages of different polarities are applied to each liquid crystal layer in two adjacent recovery regions, the equipotential line EQ representing the electric field generated in each of the two recovery regions is not continuous. These drops rapidly on the opening region 15. Therefore, a sharp potential gradient is formed around the edge portion of the opening region 15, that is, around the unit solid portion 14a, and a stronger gradient electric field is generated than in the case shown in Fig. 13A.

As described above, inverting the adjacent elements along the row direction D2 achieves sufficient orientation regulating force even if the one-side space s in the row direction D2 is shortened. Therefore, even if a configuration is adopted in which the distance between adjacent recovery electrodes 14 is shortened along the row direction D2 so that the aperture ratio becomes high, a sufficiently stable radial inclination orientation can be formed.

As described above, a liquid crystal display device having a specific specification (approximately square with a diagonal of the display area of 15 inches and each portion of the unit solid portion 14a being substantially arc-shaped, the width of the gate bus line and the light shielding layer on the source bus line). A further experiment was conducted on a liquid crystal display device having a width of 12 µm and an interval of unit solid portions 14a of 8.5 µm. In particular, the case of inverting driving of adjacent elements along the row direction D2 and the case of not inverting driving were examined. In the case of not inverting the adjacent sweeps along the row direction D2, the distance between the sweep electrodes 14 required to realize a stable radial inclined alignment state was 85 µm which is the same as the distance between the unit solid portions 14a in the sweep region. . On the contrary, in the case of inverting driving adjacent to each other along the row direction D2, a stable radial inclination alignment state was obtained even if the distance between the adjacent collecting electrodes 14 along the row direction D2 was shortened to 3 µm.

In the present embodiment, when the inverse driving of adjacent elements along the row direction D2 is inverted, even when the inversion driving is not inverted along the column direction D1 (so-called source line inversion driving) as shown in FIG. 14A, the aperture ratio is sufficiently increased. Can improve. Nevertheless, from the viewpoint of suppressing flickering or the like, it is preferable to invert the adjacent elements along the row direction D2 and to invert the elements every n (n is an integer of 1 or more) along the column direction D1. That is, it is preferable to invert the polarity of the voltage applied to the liquid crystal layer of the recovery region belonging to the same column every n rows within one frame.

For example, as shown in Fig. 14B, the reverse driving may be performed every two rows along the column direction D1 (so-called "2H dot inversion driving"). Alternatively, as shown in Fig. 14C, the reverse driving may be performed for each row along the column direction D1 (so-called dot inversion driving). As shown in Fig. 14C, if the inverse driving is performed in a row along the column direction D1 while the inverse driving is performed in a row along the column direction D1, the inverse driving is performed in the row direction along the column direction D1. The interval between adjacent recovery electrodes 14 along D1 can be shortened, and the aperture ratio can be further improved.

Here, the relationship between the shape of the unit solid portion 14a, the stability of the radial inclination orientation and the value of the transmittance will be described.

The inventors of the present application found that when the interval (one-sided space s) of the unit solid portion 14a is constant, the orientation stability is higher as the shape of the unit solid portion 14a is closer to a circle or an ellipse. This is because the closer the shape of the unit solid portion 14a is to the circle or the ellipse, the higher the continuity of the alignment direction of the liquid crystal molecules 30a in the radial oblique alignment state.

In addition, it was found that the closer the shape of the unit solid portion 14a is to a square such as a square or a rectangle, the higher the transmittance. This is because when the value of the one-sided space s is the same, the closer the shape of the unit solid portion 14a is to the spherical shape, the higher the area ratio of the solid portion 14b is, so that it is directly affected by the electric field generated by the electrode. This is because the area of the liquid crystal layer (defined in the plane when viewed from the substrate normal line direction) becomes large, and the effective aperture ratio becomes high.

Therefore, what is necessary is just to determine the shape of the unit solid part 14a in consideration of desired orientation stability and transmittance | permeability.

As shown in Figs. 9 and 10, the unit solid portion 14a can make both the orientation stability and the transmittance relatively high as long as the respective portions are substantially square in an arc shape. Of course, the same effect can be acquired even if each unit part is substantially spherical in an arc shape. Each part of the unit solid part 14a formed from the electrically conductive film becomes a obtuse polygonal shape (a shape composed of a plurality of angles exceeding 90 °), not strictly an arc, due to constraints in the manufacturing process. In some cases, not only a quarter arc shape or a regular polygonal shape (for example, a part of a regular polygon) but also a slightly deformed arc shape (a part of an ellipse) or an uneven polygonal shape may be used. Moreover, it may become a shape comprised by the combination of a curve and an obtuse angle. In this specification, the shape mentioned above is also included and is called substantially circular arc shape. For the same manufacturing process, even in the case of a substantially circular unit solid portion 14a as shown in Fig. 1A, it may be a polygonal shape or a slightly deformed shape instead of a rigid circle.

In view of the response speed, the shape of the unit solid portion 14a may be the same as that of the liquid crystal display device 100F shown in FIG. 15. In the liquid crystal display device 100F shown in FIG. 15, the shape of the unit solid portion 14a of the recovery electrode 14 is a distorted square in which each portion is acute. Acute angles mean that each of the corners is composed of an angle or a curve of less than 90 °.

As shown in FIG. 15, when the unit solid portion 14a has a sharp angled shape, more edge portions for generating a gradient electric field are formed, so that a gradient electric field is applied to more liquid crystal molecules 30a. Can act. Therefore, since the number of liquid crystal molecules 30a which first begin to incline in response to an electric field increases, and the time required for the formation of the radial inclination orientation is shortened over the entire recovery region, a voltage is applied to the liquid crystal layer 30. When the response time is increased.

In addition, when the shape of the unit solid portion 14a is an acute angle, the liquid crystal molecules 30a are oriented in a specific azimuth direction as compared with the case where the shape of the unit solid portion 14a is approximately circular or approximately spherical. ) Can increase (or lower) the probability of existence. That is, it is possible to have high directivity depending on the existence probability of the liquid crystal molecules 30a oriented along each of all azimuth directions. Accordingly, in a liquid crystal display device having a polarizing plate and in which linearly polarized light is incident on the liquid crystal layer 30, when each of the unit solid portions 14a is acutely angled, the polarizing plate is perpendicularly or parallel to the polarization axis of the polarizing plate. The existence probability of the liquid crystal molecules 30a that are oriented, that is, the liquid crystal molecules 30a which do not generate a phase difference with respect to the incident light can be lowered. Therefore, light transmittance can be improved and brighter display can be achieved.

The configuration of the liquid crystal display device according to the first embodiment described above includes the plurality of unit solid portions 14a arranged in a line along one side of the cycle direction of the sweep, and the cycle direction of the sweep. Except for inverting driving the adjacent elements along the other side, the same configuration as that of the known vertically aligned liquid crystal display device can be adopted, and the production can be performed by a known production method.

Typically, in order to vertically align liquid crystal molecules having negative dielectric anisotropy, a vertical alignment film (not shown) as a vertical alignment layer is formed on the surface of the liquid crystal layer 30 of the recovery electrode 14 and the counter electrode 22. Formed.

As the liquid crystal material, a nematic liquid crystal material having negative dielectric anisotropy is used. Moreover, it is also possible to obtain the liquid crystal display device of a guest-host mode by adding a dichroic dye with 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.

2nd embodiment

With reference to FIG. 16A and 16B, the structure of one recovery area | region of the liquid crystal display device 200 of 2nd Embodiment which concerns on this invention is demonstrated. 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. 16A is a plan view seen from the substrate normal direction, and FIG. 16B corresponds to a cross sectional view along the line 16B-16B ′ of FIG. 1A. 16B shows a state where no voltage is applied to the liquid crystal layer.

As shown in FIGS. 16A and 16B, in the liquid crystal display device 200, the TFT substrate 200a has a convex portion 40 inside the opening region 15 of the recovery electrode 14. And the liquid crystal display device 100 of the first embodiment shown in 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 of the board | substrate 11 in the in-plane direction is the same as that of the opening area | region 15 as shown in FIG. 16A, and is a substantially star shape here. However, adjacent convex parts 40 are mutually connected and are formed so that the unit solid part 14a may be completely enclosed in a substantially circular shape. The cross-sectional shape in the in-plane direction perpendicular to the substrate 11 of the convex portion 40 is trapezoidal as shown in FIG. 16B. That is, it has 40 t of parallel planes parallel to a board | substrate surface, and the side surface 40s inclined at taper angle (theta) (<90 degrees) with respect to a board | substrate surface. Since a vertical alignment film (not shown) is formed to cover the convex portion 40, the side surface 40s of the convex portion 40 is inclined 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 by this, and acts to stabilize radial oblique orientation.

The operation of the convex portion 40 will be described with reference to Figs. 17A to 17D and Figs. 18A and 18B.

First, the relationship between the orientation of the liquid crystal molecules 30a and the shape of the surface having vertical alignment is described with reference to FIGS. 17A to 17D.

As shown in FIG. 17A, 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 rotated clockwise or counterclockwise. Inclined torque acts with equal probability. Therefore, in the liquid crystal layer 30 between the mutually parallel electrodes arranged parallel, the liquid crystal molecule 30a which receives the torque of clockwise rotation, and the liquid crystal molecule 30a which receives the counterclockwise torque 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. 17B, 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. In order to be parallel, the inclination amount is inclined in a direction (clockwise rotation in the illustrated example). Further, as shown in FIG. 17C, the liquid crystal molecules 30a oriented vertically with respect to the horizontal surface are aligned so that their alignment is continuous with the liquid crystal molecules 30a oriented perpendicular to the inclined surface (matching). Inclined in the same direction (clockwise rotation direction) as that of the liquid crystal molecules 30a positioned on the inclined surface.

As shown in Fig. 17D, for continuous concave-convex surfaces having a trapezoidal cross section, the liquid crystal molecules on the front and bottom surfaces are matched with the alignment direction regulated by the liquid crystal molecules 30a on each inclined surface. 30a) is oriented.

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

18A and 18B show a state where a voltage is applied to the liquid crystal layer 30 shown in FIG. 16B, respectively. 18A schematically shows a state in which the orientation of the liquid crystal molecules 30a starts to change in accordance with the voltage applied to the liquid crystal layer 30 (initial ON state). 18B 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. Curved EQs of FIGS. 18A and 18B represent equipotential lines.

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. 16B, 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 oriented vertically with respect to the side surface 40s, and the liquid crystal molecules 30a near the side surface 40s. ) Has an inclined orientation as shown in the diagram, due to the interaction with the surrounding liquid crystal molecules 30a (properties as an elastic body).

When a voltage is applied to the liquid crystal layer 30, a potential gradient represented by the equipotential line EQ shown in Fig. 18A 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. Of the opening region 15 that is parallel and is dropped in an area corresponding to the opening region 15 of the recovery electrode 14 and includes an edge portion of the opening region 15 (the boundary (the outer edge) of the opening region 15). Inside the liquid crystal layer 30 on the EG, an inclined electric field represented by an inclined equipotential line EQ is formed.

As described above, the liquid crystal molecules 30a on the edge portion EG are inclined in the clockwise (rotational) direction in the right edge portion EG of FIG. 18A, as described above, by the gradient electric field. On the left edge of EG, it is inclined counterclockwise (rotational) and oriented parallel to the equipotential line EQ. The orientation regulation direction by this gradient electric field is the same as the orientation regulation direction along 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. 18B is obtained. The liquid crystal molecules 30a positioned near the center of the opening region 15, that is, near the center of the constant plane 40t of the convex portion 40 are formed at the edge portions EG on both sides of the opening region 15 facing each other. Since the influence of the alignment of the liquid crystal molecules 30a is almost equal, the alignment state perpendicular to the equipotential line EQ is maintained and at the center of the opening region 15 (the constant plane 40t of the convex portion 40). The liquid crystal molecules 30a in the deviated region are inclined under the influence of the orientation of the liquid crystal molecules 30a of the edge portion EG near each other, and thus the liquid crystal molecules 30a of the opening region 15 (the constant plane 40t of the convex portion 40) are inclined. It forms an oblique orientation that is symmetrical about the center SA. Further, even in a region corresponding to the unit solid portion 14a substantially surrounded by the opening region 15 and the convex portion 40, an inclined orientation symmetrical with respect to the center SA of the unit solid portion 14a is formed.

As described above, also in the liquid crystal display device 200 of the second embodiment, the liquid crystal domain having the radial inclination alignment is formed in the opening region 15 and the unit solid portion 14a as in the liquid crystal display device 100 of the first embodiment. It is formed corresponding to). Since the convex portion 40 is formed to completely surround the unit solid portion 14a 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 inside the opening area 15 inclines the liquid crystal molecule 30a of the edge part EG of the opening area 15 to the same direction as the orientation direction by a gradient electric field. To stabilize the radial oblique orientation.

Although the orientation regulating force by the gradient electric field is natural, it acts only when voltage is applied, and the strength depends on the intensity of the electric field (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 weakened, and when an external force is applied to the liquid crystal panel, the radial oblique orientation may be broken by 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 control 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 the "anchoring effect" of an alignment film. Therefore, even if the liquid crystal material flows 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 oblique orientation is easily restored.

As described above, the liquid crystal display device 200 according to the second embodiment has a feature that the liquid crystal display device 100 according to the first embodiment has a strong external force. Therefore, the liquid crystal display device 200 is suitably used for a personal computer or a PDA which is easy to carry and has many opportunities to carry.

When the convex part 40 is formed using a dielectric with high transparency, the advantage that the contribution ratio to the display of the liquid crystal domain formed corresponding to the opening area 15 is improved is obtained. On the other hand, when the convex portion 40 is formed using an opaque dielectric, it is possible to prevent light leakage due to the retardation of the liquid crystal molecules 30a which are inclinedly aligned along the side surface 340s of the convex portion 40. Advantage is obtained. What is adopted may be determined considering the use of a liquid crystal display device, and the like. In any case, the use of the photosensitive resin has the advantage of simplifying the process of patterning corresponding to the opening region 15. In order to obtain 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 described above, the liquid crystal display device 200 has a convex portion 40 inside the opening region 15 of the recovery electrode 14, and the side surface 40s of the convex portion 40 has a liquid crystal layer ( With respect to the liquid crystal molecules 30a of 30), they have an orientation regulation force in the same direction as the orientation regulation direction by the gradient electric field. Preferable 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. 19A to 19C.

19A to 19C schematically show cross-sectional views of the liquid crystal display devices 200A, 200B, and 200C, respectively. 19A to 19C correspond to FIG. 18A. Although all of the liquid crystal display devices 200A, 200B, and 200C have convex portions inside the opening portion 40, the arrangement relationship between the entire convex portion 40 and the opening portion 40 as one structure is determined by the liquid crystal display device 200. Is different from

In the above-mentioned liquid crystal display device 200, as shown in FIG. 18A, the whole convex part 40 as a structure is formed in the inside of the opening part 40a, and the bottom face of the convex part 40 is an opening part. It is smaller than 40a. In the liquid crystal display 200A shown in FIG. 19A, the bottom of the convex portion 40A coincides with the opening region 15. In the liquid crystal display device 200B shown in FIG. 19B, the convex portion 40B is the opening region. It has a bottom surface larger than (15) and is formed so as to cover the solid portion (conductive film) 14b around the opening region 15. The solid part 14b is not formed on any side surface 40s 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 is dropped to the opening area 15 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. Orientation regulation in the direction is generated to stabilize the radial oblique orientation.

In contrast, the bottom of the convex portion 40C of the liquid crystal display device 200C shown in FIG. 19C is larger than the opening region 15, and a part of the solid portion 14b extending into the region on the opening region 15 is convex. It is formed on the side surface 40s of the part 40C. A ridge portion is formed in the equipotential line EQ under the influence of a portion of the solid portion 14b formed on the side surface 40s. The ridge of the equipotential line EQ has a slope opposite to that of the equipotential line EQ dropped into the opening region 15. This means that a gradient electric field in the reverse direction is generated from a gradient electric field for radially aligning 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 regulation direction by a gradient electric field, it is preferable that the solid part (electroconductive film) is not formed on the side surface 40s.

Next, with reference to FIG. 20, the cross-sectional structure along the line 20A-20A 'of the convex part 40 shown in FIG. 16A is demonstrated.

As described above, since the convex portion 40 shown in Fig. 16A is formed so as to completely surround the unit solid portion 14a in a substantially circular shape, it serves to interconnect with the adjacent unit solid portions 14a. The part (branch part from a circular part to 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 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. 21A and 21B, when the independent convex portions 40D are formed to be completely included in the opening regions 15, the conductive portions form the solid portions 14b. In the film, since the substrate 11 is formed on a flat surface, there is no risk of disconnection or peeling. The convex portion 40D is not formed to completely enclose the unit solid portion 14a in a substantially circular shape, but a substantially circular liquid crystal domain corresponding to the unit solid portion 14a is formed, and as in the previous example, Its radial oblique orientation is stabilized.

By forming the convex portion 40 in the opening region 15, the effect of stabilizing the radial inclination orientation is not limited to the opening region 15 of the illustrated pattern, and the opening regions of all the patterns described in the first embodiment ( The same effect can be applied to 15), and the same effect can be obtained. In order to sufficiently obtain the orientation stabilization effect against the external force by the convex portion 40, the pattern of the convex portion 40 (pattern as viewed in the substrate normal direction) may be used to cover the liquid crystal layer 30 in the widest possible region. The shape that surrounds is preferable. Thus, for example, the positive pattern having the circular unit solid portion 14a has a larger orientation stabilizing effect by the convex portion 40 than the negative pattern having the circular opening region 15.

Third embodiment

The liquid crystal display device of the third embodiment according to the present invention differs from the liquid crystal display device 100 of the first embodiment shown in FIGS. 1A and 1B in that the opposing substrate has an alignment regulating structure.

22A to 22E schematically show an opposing substrate 300b having an alignment regulating structure 28. Components that are substantially the same as those of the above-described liquid crystal display device are denoted by common reference numerals, and description thereof is omitted here.

The alignment regulating structure 28 shown in FIGS. 22A to 22E functions to radially orient the liquid crystal molecules 30a of the liquid crystal layer 30. However, the orientation control structure 28 shown to FIG. 22A-22D and the orientation control structure 28 shown to FIG. 22E differ in the direction which inclines the liquid crystal molecule 30a.

The inclination direction of the liquid crystal molecules according to the alignment regulating structure 28 shown in FIGS. 22A to 22D is a region corresponding to the unit solid portion 14a (see, for example, FIGS. 1A and 1B) of the recovery electrode 14. It is aligned with the alignment direction of the radial oblique alignment of the liquid crystal domain formed in the. In contrast, the inclination direction of the liquid crystal molecules by the alignment regulating structure 28 illustrated in FIG. 22E is the radial inclination orientation of the liquid crystal domain formed in the region corresponding to the opening region 15 (see FIG. 1, for example). Match the orientation direction.

The orientation regulating structure 28 shown in FIG. 22A includes an opening 22a of the counter electrode 22 and a recovery electrode facing the opening 22a (not shown here, for example, see FIG. 1A) 14. It is comprised by the unit solid part 14a of the. A vertical alignment film (not shown) is formed on the surface of the opposing substrate 300b on the liquid crystal layer 30 side.

This orientation regulation structure 28 generates an orientation regulation force only when voltage is applied. Since the orientation regulation structure 28 should just act as an orientation regulation force with respect to the liquid crystal molecule in the liquid crystal domain which takes the radial oblique orientation formed by the electrode structure of the TFT substrate 100a, the magnitude | size of the opening part 22a is a TFT substrate. It is smaller than the opening area | region 15 formed in 100a, and smaller than the unit solid part 14a (for example, FIG. 1A) enclosed by the opening area 15. As shown in FIG. For example, a sufficient effect can be obtained at half or less of the area of the opening region 15 and the unit solid portion 14a. By forming the opening 22a of the counter electrode 22 at a position opposed to the central portion of the unit solid portion 14a of the recovery electrode 14, the continuity of the alignment of the liquid crystal molecules is increased, and the center axis of the radial oblique alignment is The position can be fixed.

As such, when the structure for generating the orientation regulating force only when voltage is applied is adopted as the orientation regulating structure, almost all liquid crystal molecules 30a of the liquid crystal layer 30 take a vertical alignment state in a voltage-free state. Therefore, when the normal black mode is adopted, light leakage hardly occurs in the black display state, and display of a good contrast ratio can be realized.

However, since no orientation regulating force is formed in a voltage-free state, since the radial inclination orientation is not formed, and when the applied voltage is low, since the orientation regulating force is small, an afterimage may be visually recognized when too large a stress is applied to the liquid crystal panel. .

The orientation regulating structure 28 shown in FIGS. 22B to 22D generates an orientation regulating force regardless of whether voltage is applied or not, so that stable radial inclination orientation is obtained in all display gradations, and is also excellent in resistance to stress. Do.

First, the alignment regulation structure 28 shown in FIG. 22B has a convex portion 22b protruding toward the liquid crystal layer 30 on the counter electrode 22. Although there is no restriction | limiting in particular in the material which forms the convex part 22b, It can form easily using dielectric materials, such as resin. Further, a vertical alignment film (not shown) is formed on the surface of the opposing substrate 600b on the liquid crystal layer 30 side. The convex part 22b inclines and aligns the liquid crystal molecule 30a radially by the shape effect of the surface (having vertical orientation). If a resin material deformed by heat is used, the convex portion 22b having a gentle hill-shaped cross-sectional shape can be easily formed by heat treatment after patterning, as shown in Fig. 22B. desirable. As shown in the figure, the convex portion 22b having a smooth cross-sectional shape (for example, a part of a sphere) having a vertex or the convex portion having a conical shape has an excellent effect in fixing the center position of the radial inclination orientation.

The alignment regulating structure 28 shown in FIG. 22C has a liquid crystal layer 30 in an opening (may be a concave portion) 23a formed in the dielectric layer 23 formed below the counter electrode 22 (substrate 21 side). It is comprised by the horizontally oriented surface of the side. Here, the vertical alignment film 24 formed on the liquid crystal layer 30 side of the opposing substrate 300b is not formed only in the opening 23a, thereby making the surface in the opening 23a a horizontally oriented surface. Instead of this, as shown in FIG. 22D, the horizontal alignment film 25 may be formed only in the opening 23a.

In the horizontal alignment film shown in FIG. 22D, for example, the vertical alignment film 24 is once formed on the entire surface of the opposing substrate 300b, and ultraviolet rays are selectively irradiated to the vertical alignment film 24 existing in the opening 23a. You may form by reducing the vertical orientation. With respect to the horizontal alignment necessary for forming the alignment regulating structure 28, the pretilt angle does not need to be small as in the alignment film used in the TN type liquid crystal display device, and the pretilt angle may be 45 ° or less, for example. .

As shown in FIGS. 22C and 22D, on the horizontally oriented surface in the opening portion 23a, since the liquid crystal molecules 30a try to align horizontally with respect to the substrate surface, the liquid crystals that are vertically aligned on the peripheral vertical alignment film 24. An orientation that maintains the orientation and continuity of the molecules 30a is formed, and a radial oblique orientation as shown is obtained.

Selecting a horizontally oriented surface (such as an electrode surface or a horizontal alignment film) on the flat surface of the counter electrode 22 without forming a recess (formed by the opening of the dielectric layer 23) on the surface of the counter electrode 22. Although the radial inclination orientation is obtained only by forming it, the radial inclination orientation can be further stabilized by the shape effect of the concave portion.

In order to form a recess in the surface on the side of the liquid crystal layer 30 of the counter substrate 300b, for example, when the dielectric layer 23 is used as the color filter layer or the overcoat layer of the color filter layer, the process does not increase, so it is preferable. Do. In addition, the structure shown in Figs. 22C and 22D has a region where voltage is applied to the liquid crystal layer 30 through the convex portion 22b, similarly to the structure shown in Fig. 22A. Less deterioration

The alignment control structure 28 shown in FIG. 22E is similar to the alignment control structure 28 shown in FIG. 22D, using the opening 23a of the dielectric layer 23, and the liquid crystal layer 30 of the opposing substrate 300b. The recessed part is formed in the () side, and the horizontal alignment film 26 is formed only in the bottom part of the recessed part. Instead of forming the horizontal alignment layer 26, the surface of the counter electrode 22 may be exposed as shown in FIG. 22C.

23A and 23B show a liquid crystal display device 300 having the first alignment control structure and the alignment control structure described above. FIG. 23A is a plan view and FIG. 23B corresponds to a sectional view along the line 23B-23B 'in FIG. 23A.

The liquid crystal display device 300 includes a TFT electrode 100a having a storage electrode 14 having an unit solid portion 14a and an opening region 15, and an opposing substrate 300b having an alignment regulating structure 28. Have The structure of TFT substrate 100a is not limited to the structure illustrated here, The above-mentioned various structures can be used suitably. Moreover, although the orientation regulation structure 28 generate | occur | produces orientation regulation force even when a voltage is not applied (FIGS. 22B-22D and 22E), it demonstrates instead of the orientation regulation structure 28 shown to FIG. 22B-22D. It is also possible to use what is shown in FIG. 22A.

Of the alignment regulating structures 28 formed on the opposing substrate 300b of the liquid crystal display device 300, the alignment regulating structure is formed near the center of the region facing the unit solid portion 14b of the recovery electrode 14. 22B to 22D is any one of those shown in FIG. 22E, and the alignment regulating structure 28 formed near the center of the region facing the opening 14a of the recovery electrode 14 is shown in FIG. 22E. It is.

By this arrangement, the unit solid portion 14a of the recovery electrode 14 is in a state where a voltage is applied to the liquid crystal layer 30, that is, a voltage is applied between the recovery electrode 14 and the counter electrode 22. The direction of the radial inclination orientation formed by) and the direction of the radial inclination orientation formed by the orientation regulating structure 28 are matched, and the radial inclination orientation is stabilized. This state is schematically shown in Figs. 24A to 24C. Fig. 24A shows a time when no voltage is applied, and Fig. 24B shows a state in which the orientation has started to change after the voltage is applied (initial ON state), and Fig. 24C schematically shows a steady state during voltage application.

As shown in Fig. 24A, the alignment regulating force by the alignment regulating structure (Figs. 22B to 22D)) 28 acts on the liquid crystal molecules 30a in the vicinity even in the absence of voltage to form radial oblique alignment.

When voltage is applied, an electric field represented by an equipotential line EQ as shown in FIG. 24B is generated (by the electrode structure of the TFT substrate 100a), which corresponds to the opening region 15 and the solid portion 14a. The liquid crystal domain in which the liquid crystal molecules 30a are radially oriented is formed in the region, and reaches a steady state as shown in Fig. 24C. At this time, the inclination direction of the liquid crystal molecules 30a in each liquid crystal domain coincides with the inclination direction of the liquid crystal molecules 30a due to the alignment regulating force of the alignment regulating structure 28 formed in the corresponding region.

When the stress is applied to the liquid crystal display device 300 in a steady state, the radial oblique alignment of the liquid crystal layer 30 collapses once, but when the stress is removed, the unit solid portion 14a and the alignment regulating structure 28 Since the alignment regulating force is acting on the liquid crystal molecules 30a, it returns to the radial oblique alignment state. Therefore, generation | occurrence | production of an afterimage by stress is suppressed. If the orientation regulating force by the orientation regulating structure 28 is too strong, retardation due to radial oblique orientation may occur even when no voltage is applied, and the contrast ratio of the display may decrease, but the orientation regulating force by the orientation regulating structure 28 Since the stabilization of the radial oblique alignment formed by the first alignment regulating structure and the effect of fixing the central axis position need only be effected, a strong alignment regulating force is not necessary and the degree of deterioration of the display quality is not generated. The orientation control force is enough.

For example, when the convex part 22b shown in FIG. 22B is employ | adopted, with respect to the unit solid part 14a which is about 30 micrometers-about 35 micrometers in diameter, each has a diameter of about 15 micrometers, and height (thickness) is about 1 micrometer. When the convex part 22 is formed, sufficient orientation control force is obtained, and also the fall of contrast ratio by retardation is suppressed to the level which is satisfactory practically.

25A and 25B show another liquid crystal display device 400 having an alignment regulating structure.

The liquid crystal display device 400 does not have an orientation regulation structure in the area | region which opposes the opening area | region 15 of the TFT substrate 100a. It is difficult to form the alignment regulating structure 28 shown in FIG. 22E to be formed in the region opposite the opening region 15. Therefore, from the viewpoint of productivity, it is preferable to use only one of the alignment regulating structures 28 shown in Figs. 22A to 22D. In particular, the orientation regulating structure 28 shown in Fig. 22B is preferable because it can be manufactured by a simple process.

Although the alignment regulating structure is not formed in a region corresponding to the opening region 15 like the liquid crystal display device 400, as shown schematically in FIGS. 26A to 26C, the radial inclination similar to that of the liquid crystal display device 300 is obtained. An orientation is obtained and its stress resistance also has no problem practically.

An example of the liquid crystal display device which has an orientation regulation structure in FIG. 27A, 27B, and 27C is shown. 27A, 27B, and 27C are cross-sectional views schematically showing a liquid crystal display device 500 having an alignment regulating structure. Fig. 27A shows a time when no voltage is applied, Fig. 27B shows a state in which the orientation starts to change after the voltage is applied (initial ON state), and Fig. 27C schematically shows a steady state during voltage application.

The liquid crystal display device 500 includes a convex portion 40 shown in FIG. 16 inside the opening region 15 of the TFT substrate 200a. The convex portion 22b shown in FIG. 22B is provided as an orientation regulating structure 28 formed near the center of the region of the storage electrode 14 that faces the unit solid portion 14a.

In the liquid crystal display device 500, the radial inclination orientation is stabilized by the alignment control force by the side surface 40s of the convex portion 40 and the alignment control force by the surface of the convex portion 22b. Since the above-described alignment control force due to the shape effect of the convex portion 40 and the convex portion 22b stabilizes the radial inclined alignment state regardless of the applied voltage, the liquid crystal display device 500 has good stress resistance. have.

As the orientation regulation structure 28, when the convex part 22b which protruded toward the liquid crystal layer 30 side on the counter electrode 22 as shown in FIG. 22B is employ | adopted, the liquid crystal by the convex part 22b The thickness of the layer 30 may be defined. That is, the convex part 22b may be set as a structure which also functions as a spacer which controls a cell gap (thickness of the liquid crystal layer 30).

28A and 28B show a liquid crystal display device 600 having a convex portion 22b that also functions as a spacer. FIG. 28A is a plan view seen from the substrate normal direction, and FIG. 28B corresponds to a sectional view along the line 28B-28B 'of FIG. 28A.

As shown in FIGS. 28A and 28B, the liquid crystal display device 600 is a convex portion 22b formed in the vicinity of the center of the region facing the unit solid portion 14a of the recovery electrode 14 as the alignment regulating structure 28. ), The thickness of the liquid crystal layer 30 is defined. Therefore, if such a configuration is adopted, there is no need to separately form a spacer defining the thickness of the liquid crystal layer 30, and there is an advantage that the manufacturing process can be simplified.

Here, the convex part 22b is a truncated cone shape as shown to FIG. 28B, and the side surface inclined at the taper angle (theta) less than 90 degrees with respect to the board | substrate surface of the board | substrate 21 ( 22b1). When the side surface 22b1 is inclined at an angle of less than 90 ° with respect to the substrate surface, the side surface 22b1 of the convex portion 22b is regulated by the inclination electric field with respect to the liquid crystal molecules 30a of the liquid crystal layer 30. It has an orientation control force in the same direction as the direction, and acts to stabilize the radial oblique orientation.

As schematically shown in Figs. 29A to 29C, also in the liquid crystal display device 600 having the convex portion 22b which also functions as a spacer, the same radial oblique orientation as in the liquid crystal display devices 300 and 400 is obtained. .

In FIG. 28B, the convex portion 22b having the side surface 22b1 inclined at an angle of less than 90 ° with respect to the substrate surface is shown, but the convex portion having the side surface 22b1 inclined at an angle of 90 ° or more with respect to the substrate surface. The part 22b may be sufficient. From the viewpoint of stabilizing the radial inclination orientation, the inclination angle of the side surface 22b1 preferably does not exceed 90 degrees, and more preferably less than 90 degrees. Even when the inclination angle exceeds 90 °, when it is close to 90 ° (unless exceeding 90 ° significantly), the liquid crystal molecules 31 near the inclined side surface 22b1 of the convex portion 22b are separated from the substrate surface. Since it is inclined in the substantially horizontal direction, only slight distortion occurs and radial oblique alignment is made while matching with the inclination direction of the liquid crystal molecules 31 of the edge portion. However, as shown in FIG. 30, if the side surface 22b1 of the convex part 22b inclines more than 90 degrees, the side surface 22b1 of the convex part 22b will be a liquid crystal molecule of the liquid crystal layer 30. As shown in FIG. With respect to (30a), since the orientation regulation force in the direction opposite to the orientation regulation direction by the gradient electric field is provided, the radial gradient orientation may become unstable.

In addition, as the convex part 22b which also functions as a spacer, it is not limited to the cone trapezoid shape shown to FIG. 28A and b. For example, as shown in FIG. 31, the convex part 22b of the cross-sectional shape of the in-plane direction perpendicular | vertical to a board | substrate surface may use the same part of an ellipse (namely, it has the same shape as a part of an ellipse sphere). In the convex part 22b shown in FIG. 31, although the inclination angle (taper angle) with respect to the board | substrate surface of the side surface 22b1 changes along the thickness direction of the liquid crystal layer 30, it is the one of the thickness direction of the liquid crystal layer 30. Since the inclination angle of the side surface 22b1 is less than 90 degrees also in this position, such a convex part 22b can also be used suitably as a convex part which stabilizes radial inclination orientation.

Moreover, as mentioned above, the convex part 22b which contact | connects the upper and lower board | substrates (TFT board | substrate and opposing board | substrate), and also functions as a spacer which defines the thickness of the liquid crystal layer 30 is any of the upper and lower sides in the manufacturing process of a liquid crystal display device. It may be formed on a substrate. Regardless of which substrate is formed, when the upper and lower substrates are joined, the convex portions 22b come into contact with both substrates, function as spacers, and also function as an orientation regulating structure.

In addition, not all of the convex portions 22b formed in the region facing the unit solid portions 14a need to function as spacers. By forming some convex part 22b lower than the convex part 22b which functions as a spacer, generation | occurrence | production of light leakage can be suppressed.

32, 33, and 34 show other liquid crystal display devices 600A, 600B, and 600C having an alignment regulating structure. Each of the liquid crystal display devices 600A, 600B, and 600C shown in FIGS. 32, 33, and 34 has a convex portion as an orientation regulating structure in an area of the liquid crystal display device 14 that is opposed to the unit solid portion 14a. 22b).

In the liquid crystal display device 600A shown in FIG. 32, the unit solid portion 14a located on the storage capacitor wiring 43 is slightly smaller than the other unit solid portions 14a, and the liquid crystal display device shown in FIG. In 600B), the unit solid portion 14a located on the storage capacitor wiring 43 is larger than the other unit solid portions 14a. In this manner, the plurality of unit solid portions 14a of the recovery electrode 14 need not necessarily be the same size in the recovery region. In particular, the liquid crystal domain formed in the unit solid portion 14a positioned on the opaque component such as the storage capacitor wiring 43 does not contribute to the display in the transmissive liquid crystal display device. A sufficiently stable radial oblique orientation may not be formed in the seal portion 14a, and the unit solid portion 14a may have a shape and size different from those of the other unit solid portions 14a. For example, in the liquid crystal display device 600C illustrated in FIG. 34, the shape of the unit solid portion 14a positioned on the storage capacitor wiring 43 is cylindrical (approximately spherical shape in which each portion is approximately arc-shaped). The other unit solid portion 14a has a substantially star shape.

In addition, although the structure which the unit solid part 14a is located here on the storage capacitor wiring 43 was illustrated, if it is located so that it may become the opening area 15 on opaque components, such as the storage capacitor wiring 43, In this configuration, the ratio of the area contributing to the display in the subregion can be increased, and the brightness is improved.

Arrangement of polarizing plate and retardation plate

The so-called "vertical alignment type liquid crystal display device" includes a liquid crystal layer in which the liquid crystal molecules having negative dielectric anisotropy are vertically aligned when no voltage is applied, and 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 optical rotation mode, the optical refraction mode, and the birefringence mode. By forming a pair of polarizing plates on the outer side (the opposite side to the liquid crystal layer 30) of a pair of substrates (for example, a TFT substrate and a counter substrate) of all the liquid crystal display devices mentioned above, the liquid crystal display device of birefringence mode can be obtained. . If necessary, a phase difference compensating element (typically a phase difference plate) may be formed. Further, even when circularly polarized light is used, a bright liquid crystal display device can be obtained.

According to the invention, the liquid crystal domain with radial oblique orientation is formed stably, with high continuity. Therefore, the display quality of the conventional liquid crystal display device having the wide viewing angle characteristic can be further improved.

Further, in each of the recovery areas, the plurality of unit solid parts are arranged along a predetermined direction, that is, arranged in one row, so that the opening ratio can be improved by increasing the area ratio of the unit solid parts in the recovery area. have.

In addition, within one frame, the adjacent elements are reversely driven in a predetermined direction different from the arrangement direction of the unit solid portion. Therefore, it is possible to generate a gradient electric field having a sharp electric potential gradient between the elements adjacent in that direction. Thereby, even if the structure between the electrodes is short and the aperture ratio is high, a sufficiently stable radial inclination orientation can be formed.

As described above, according to the present invention, it is possible to provide a liquid crystal display device having a wide viewing angle characteristic, high display quality, and bright display with high opening ratio.

As mentioned above, although this invention was demonstrated based on the preferable embodiment, those skilled in the art can change this invention with various methods, and can implement it in many other embodiments other than the above-mentioned embodiment. Accordingly, the appended claims will cover all modifications within the spirit and scope of the invention.

FIG. 1 is a view schematically showing the structure of one picture element region of the liquid crystal display device 100 of the first embodiment according to the present invention, in which FIG. 1A is a plan view and FIG. 1B is 1B- in FIG. 1A. Section along the line 1B '

FIG. 2 schematically illustrates a state in which voltages having different polarities are applied to adjacent recovery regions along the row direction of the liquid crystal display 100.

FIG. 3 is a diagram illustrating a state in which a voltage is applied to the liquid crystal layer 30 of the liquid crystal display 100. FIG. 3A schematically illustrates a state in which an orientation has started to change (initial ON state), and 3b is normal. A diagram schematically showing the state

4A to 4D schematically show the relationship between the electric field lines and the alignment of liquid crystal molecules.

5A to 5C schematically show alignment states of liquid crystal molecules seen in the substrate normal direction in the liquid crystal display device 100.

6A-6C schematically illustrate an example of radial oblique alignment of liquid crystal molecules;

7A and 7B schematically show another liquid crystal display device 100A and 100B of the first embodiment according to the present invention.

8A and 8B are plan views schematically showing still another liquid crystal display device 100C and 100D of the first embodiment according to the present invention.

9 is a plan view schematically showing another liquid crystal display device 100E of the first embodiment according to the present invention.

10 is a plan view schematically showing another liquid crystal display device 100E of the first embodiment according to the present invention.

11 is a plan view schematically showing the liquid crystal display device 1000 of the comparative example.

12 is a plan view schematically showing a recovery electrode included in the liquid crystal display device of the first embodiment according to the present invention.

13A is a diagram schematically showing an equipotential line EQ when a voltage of the same polarity is applied to two adjacent recovery regions along a row direction;

13B is a diagram schematically showing an equipotential line EQ when voltages of different polarities are applied to two adjacent recovery regions along the row direction;

14A, 14B, and 14C are diagrams for explaining a driving method used in the liquid crystal display device of the first embodiment according to the present invention.

15 is a plan view schematically showing another liquid crystal display device 100F of the first embodiment according to the present invention.

FIG. 16 is a view schematically showing the structure of one recovery area of the liquid crystal display device 200 of the second embodiment according to the present invention. FIG. 16A is a plan view and FIG. 16B is a line 16B-16B 'of FIG. 16A. According to

17A to 17D 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. 18 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. 18A schematically illustrates a state in which an orientation has started to change (initial ON state), and FIG. 18B A diagram schematically showing a steady state

19A to 19C are schematic cross sectional views of the liquid crystal display devices 200A, 200B, and 200C of the second embodiment having different arrangement relations between the openings and the convex portions.

20 is a cross-sectional view schematically illustrating the cross-sectional structure of the liquid crystal display 200, and is taken along line 20A-20A ′ of FIG. 16A.

FIG. 21 is a view schematically showing the structure of one recovery area of the liquid crystal display 200D, FIG. 21A is a plan view, and FIG. 21B is a sectional view along the line 21B-21B 'of FIG. 21A.

22A-22E schematically show an opposing substrate 300b having an orientation regulating structure 28.

FIG. 23 is a diagram schematically showing a liquid crystal display device 300 of a third embodiment according to the present invention. FIG. 23A is a plan view, and FIG. 23B is a cross-sectional view along the line 23B-23B 'in FIG. 23A.

FIG. 24 is a diagram schematically showing a cross-sectional structure of one sweep region of the liquid crystal display device 300. FIG. 24A shows a voltage-free state, and FIG. 24B shows a state in which an orientation has started to change (initial ON state). 24C is a view showing a normal state

FIG. 25 is a diagram schematically showing another liquid crystal display device 400 of a third embodiment according to the present invention, FIG. 25A is a plan view, and FIG. 25B is a cross-sectional view along the line 25B-25B 'of FIG. 25A.

FIG. 26 is a diagram schematically showing a cross-sectional structure of one sweep region of the liquid crystal display device 400. FIG. 26A shows a voltage-free state, and FIG. 26B shows a state where the orientation has started to change (initial ON state). And Fig. 26C shows a normal state

FIG. 27 is a diagram schematically showing a cross-sectional structure of one sweep region of another liquid crystal display device 500 of the third embodiment according to the present invention, where FIG. 27A shows a voltage-free state, and FIG. Fig. 27C is a diagram showing a steady state (initial ON state), and Fig. 27C shows a steady state.

FIG. 28 is a view schematically showing a liquid crystal display device 600 having convex portions functioning as spacers. FIG. 28A is a plan view, and FIG. 28B is a cross-sectional view along the line 28B-28B 'of FIG. 28A.

FIG. 29 is a diagram schematically showing a cross-sectional structure of one sweep region of the liquid crystal display device 600. FIG. 29A shows a voltage-free state, and FIG. 29B shows a state in which the orientation has started to change (initial ON state). 29C is a diagram showing a normal state

30 is a cross sectional view schematically showing a convex portion having a side surface having an inclination angle with respect to the substrate surface greatly exceeding 90 °

31 is a sectional views schematically showing a modification of the convex portion functioning as the spacer;

32 is a plan view schematically showing another liquid crystal display device 600A of a third embodiment according to the present invention.

33 is a plan view schematically showing another liquid crystal display device 600B of a third embodiment according to the present invention.

34 is a plan view schematically showing another liquid crystal display device 600C of the third embodiment according to the present invention.

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

11, 21: transparent insulating substrate

14: recovery electrode

14a: unit solid part

15: opening area

22: counter electrode

30: liquid crystal layer

30A: liquid crystal molecules

40, 40A, 40B, 40C, 40D: convex

40s: side of convex part

40t: constant plane of convex part

100, 200, 300, 400, 500, 600: liquid crystal display

100a, 200a: TFT substrate

100b, 300b: facing substrate

Claims (19)

A first substrate, A second substrate, A liquid crystal display device comprising a liquid crystal layer formed between the first substrate and the second substrate. A plurality of recovery regions are respectively formed by a first electrode formed on one side of the first substrate closer to the liquid crystal layer side, and a second electrode formed on the second substrate and opposed to the first electrode via the liquid crystal layer. Regulated, In each of the plurality of recovery regions, the first electrode includes a plurality of unit solid parts arranged along a first direction, such that a voltage is applied between the first electrode and the second electrode in the liquid crystal layer. The plurality of units by a gradient electric field generated around the plurality of unit solid portions of the first electrode when a voltage is applied between the first electrode and the second electrode when the vertical alignment state is not present. In the solid part, a plurality of liquid crystal domains each having a radial oblique alignment is formed, The plurality of recovery regions are arranged in a matrix shape including a plurality of rows extending in a second direction different from the first direction and a plurality of columns extending in the first direction, The polarity of the voltage applied to the liquid crystal layer in the first recovery area among the plurality of recovery areas belongs to the same row as the first recovery area among the plurality of recovery areas, and the first recovery area is in each frame. And a polarity of the voltage applied to the liquid crystal layer in a second recovery region belonging to a column adjacent to the column to which the column belongs. The method of claim 1, Each of the plurality of recovery regions has a shape in which a longitudinal direction is defined along the first direction and a width direction is defined along the second direction. The method of claim 1, The polarity of the voltage applied to the liquid crystal layer in the plurality of recovery regions belonging to one column of the plurality of recovery regions is inverted every n (n is an integer of 1 or more) in each frame. The method of claim 1, The polarity of the voltage applied to the liquid crystal layer in the first recovery region is, in each frame, in a third recovery region belonging to the same column as the first recovery region and belonging to a row adjacent to the row to which the first recovery region belongs. And a polarity different from that of the voltage applied to the liquid crystal layer. The method of claim 1, Each of the plurality of unit solid portions has a shape of rotation symmetry. The method of claim 5, And each of the plurality of unit solid portions is substantially circular. The method of claim 5, Each of the plurality of unit solid portions is a substantially spherical substantially circular arc-shaped liquid crystal display device. The method of claim 5, Each of the plurality of unit solid portions has a shape in which each portion is sharpened. The method of claim 1, The second substrate has an alignment regulating structure for generating an alignment regulating force for radially inclining the liquid crystal molecules in the at least one liquid crystal domain in at least a voltage applied state in a region corresponding to at least one liquid crystal domain among the plurality of liquid crystal domains. It has a liquid crystal display device characterized by the above. The method of claim 9, The alignment control structure is formed in a region near the center of the at least one liquid crystal domain. The method of claim 9, The alignment control structure generates an alignment regulating force for radially inclining the liquid crystal molecules even in a voltage-free state. The method of claim 11, And the alignment regulating structure is a first convex portion protruding from the second substrate toward the liquid crystal layer side. The method of claim 12, The thickness of the liquid crystal layer is defined by the first convex portion protruding from the second substrate toward the liquid crystal layer side. The method of claim 1, The first substrate includes a plurality of opening regions that do not overlap the first electrode, When a voltage is applied between the first electrode and the second electrode, the liquid crystal layer further forms a plurality of liquid crystal domains each having a radial oblique alignment in the plurality of opening regions by the inclined electric field. A liquid crystal display device characterized by the above-mentioned. The method of claim 14, And at least a part of the opening regions of the plurality of opening regions form a plurality of unit grids having substantially the same shape and the same size and arranged to have rotational symmetry. The method of claim 15, Wherein each shape of the at least part of the opening areas of the plurality of opening areas has rotational symmetry. The method of claim 15, And each of said at least some opening regions of said plurality of opening regions is substantially circular. The method of claim 14, A second convex portion is further included inside each of the plurality of opening regions of the first substrate, and a side surface of the second convex portion is the same as an orientation regulation direction by the inclined electric field with respect to liquid crystal molecules of the liquid crystal layer. It has an orientation regulation force of the direction, The liquid crystal display device characterized by the above-mentioned. The method of claim 1, The first substrate further includes a plurality of switching elements formed in each of the plurality of recovery regions, The first electrode includes a plurality of recovery electrodes formed for each of the plurality of recovery regions and switched by the switching element, respectively, wherein the second electrode is at least one counter electrode facing the plurality of recovery electrodes. A liquid crystal display device characterized by the above-mentioned.