JP2006113208A - Liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve high transmittance in a liquid crystal display device of a MVA (multi-domain vertically aligned) mode having an alignment division structure only on an array substrate. <P>SOLUTION: The liquid crystal display device 1 comprises an array substrate having a first alignment layer, a counter substrate having a second alignment layer as a vertical alignment layer, and a liquid crystal layer present between the substrates and containing a liquid crystal material having negative dielectric anisotropy, wherein only the array substrate of those substrates is provided with an alignment division structure SLT which divides a pixel region into a plurality of domains with different tilt directions of liquid crystal molecules while a voltage is applied. The first alignment layer is subjected to an alignment process to align the liquid crystal molecules near the first alignment layer to a direction AR crossing the longitudinal direction of the alignment division structure SLT when no voltage is applied. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a liquid crystal display device.

  According to a VA (Vertically Aligned) mode liquid crystal display device using a liquid crystal material having a negative dielectric anisotropy and a vertical alignment film, a faster response speed than a TN (Twisted Nematic) mode liquid crystal display device. Can be realized. Among them, a VA mode (hereinafter referred to as MVA mode) liquid crystal display device adopting a multi-domain method is particularly attracting attention because a wide viewing angle is relatively easy.

  In the MVA mode, each pixel region in the liquid crystal layer is divided into a plurality of domains having different tilt directions of liquid crystal molecules by forming an electric field gradient in the liquid crystal layer and / or providing protrusions on the substrate surface. To do. For example, a slit is provided in the pixel electrode, and a saddle-like dielectric pattern is shifted from the previous slit between the counter electrode and the alignment film covering the counter electrode. In this way, each pixel region can be divided into a plurality of domains with these alignment division structures, that is, slits and dielectric patterns as boundaries.

  In this structure, it is necessary to control the relative position of the slit of the pixel electrode and the dielectric pattern on the counter electrode viewed from the direction perpendicular to the display surface with high accuracy. If this relative position deviates from the design position, the boundary position between domains deviates from the design position. As a result, in each pixel region, the area of a part of the domain becomes smaller than the design value, and the area of the other part of the domain becomes larger than the design value. In this case, the viewing angle compensation effect by the multi-domain method may be impaired. Therefore, when providing an alignment division structure on both the array substrate and the counter substrate as described above, high alignment accuracy is required for bonding these substrates.

  This problem can be avoided, for example, by providing the alignment division structure only on the array substrate without providing it on the counter substrate. However, the present inventors have found that when the alignment division structure is provided only on the array substrate, the boundary between domains becomes unclear and the transmittance is lowered.

  An object of the present invention is to realize high transmittance in an MVA mode liquid crystal display device in which an alignment division structure is provided only on an array substrate.

  According to an aspect of the present invention, an array substrate including a first substrate, a plurality of pixel electrodes arranged on one main surface thereof, and a first alignment film covering the plurality of pixel electrodes, and the first substrate A counter substrate comprising: a second substrate facing the alignment film; a counter electrode provided on a surface facing the array substrate; and a second alignment film that is a vertical alignment film covering the counter electrode; A liquid crystal layer containing a liquid crystal material having a negative dielectric anisotropy and interposed between the array substrate and the counter substrate, and only the array substrate of the array substrate and the counter substrate is When a voltage is applied between the pixel electrode and the counter electrode, each pixel region, which is a region sandwiched between the pixel electrode and the counter electrode of the liquid crystal layer, has a tilt direction of liquid crystal molecules. Orientation to divide into different domains The alignment division structure is a slit provided in the pixel electrode and / or a dielectric pattern disposed between the pixel electrode and the first alignment film, and the alignment film is formed on the first alignment film. Is an alignment that aligns the liquid crystal molecules in the vicinity of the first alignment film in a direction crossing the longitudinal direction of the alignment division structure when no voltage is applied between the pixel electrode and the counter electrode. A liquid crystal display device characterized in that the treatment is performed is provided.

  According to the present invention, high transmittance can be realized in an MVA mode liquid crystal display device in which an alignment division structure is provided only on an array substrate.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same referential mark is attached | subjected to the component which exhibits the same or similar function, and the overlapping description is abbreviate | omitted.

  FIG. 1 is a plan view schematically showing a liquid crystal display device according to the first embodiment of the present invention. 2 is a cross-sectional view taken along line II-II of the liquid crystal display device shown in FIG. FIG. 3 is an enlarged plan view showing the liquid crystal display device of FIG. FIG. 4 is a plan view showing the liquid crystal display device of FIG. 1 further enlarged. FIG. 5 is a cross-sectional view taken along the line VV of the liquid crystal display device shown in FIGS. 1, 3, and 4 illustrate the liquid crystal display device viewed from the counter substrate side.

  In FIG. 1 to FIG. 5, some components are omitted for simplification. For example, in FIG. 2, the slit provided in the pixel electrode is omitted. In FIG. 3, pixel electrodes of the array substrate are drawn, and other components are omitted. In FIG. 4, the pixel electrodes and the liquid crystal molecules of the array substrate are drawn, and other components are omitted. In FIG. 5, a switching element, a color filter, a polarizing plate, and the like are omitted.

  The liquid crystal display device 1 is an MVA type liquid crystal display device. As shown in FIGS. 1, 2, and 5, the liquid crystal display device 1 includes an array substrate 2 and a counter substrate 3. The array substrate 2 and the counter substrate 3 face each other with a slight gap. The structures of the array substrate 2 and the counter substrate 3 will be described in detail later.

  As shown in FIG. 2, an adhesive layer 4 is interposed between the array substrate 2 and the counter substrate 3. The adhesive layer 4 is formed using an adhesive such as a thermosetting resin, for example. This adhesive layer 4 has a frame shape as shown in FIG. The adhesive layer 4 bonds the array substrate 2 and the counter substrate 3 to each other, and forms an empty cell together with the array substrate 2 and the counter substrate 3.

  As shown in FIG. 1, the frame formed by the adhesive layer 4 is open on one end face side of the empty cell. This opening is used as an injection port that communicates the internal space surrounded by the array substrate 2, the counter substrate 3, and the adhesive layer 4 with the external space outside.

  A transfer electrode (not shown) is interposed between the array substrate 2 and the counter substrate 3 and outside the frame formed by the adhesive layer 4. The array substrate 2 and the counter substrate 3 are electrically connected by this transfer electrode.

  The interior space of the empty cell is filled with the liquid crystal material 5 as shown in FIG. The liquid crystal material 5 forms a liquid crystal layer. In the liquid crystal display device 1, a liquid crystal material having a negative dielectric anisotropy, particularly a nematic liquid crystal having a negative dielectric anisotropy, is used as the liquid crystal material 5. For injection of the liquid crystal material into the empty cell, for example, an injection method such as a dip type or a dispenser type is used.

  As shown in FIG. 1, the empty cell inlet is closed by a sealing body 6. The sealing body 6 is formed, for example, by dispensing an adhesive such as an ultraviolet curable resin at the injection port and curing it.

  As shown in FIG. 2, a polarizing plate 7 is attached to the outer surface of the array substrate 2. A polarizing plate 7 is also attached to the outer surface of the counter substrate 3.

  As shown in FIG. 1, a signal line drive circuit 8 and a scanning line drive circuit 9 are arranged on the main surface of the array substrate 2 on the counter substrate 3 side. The liquid crystal display device 1 usually further includes a backlight that illuminates the outer surface of the array substrate 2.

Next, the structure of the array substrate 2 and the counter substrate 3 will be described.
As shown in FIG. 2, the array substrate 2 includes an insulating substrate 20 having optical transparency such as a glass substrate as a first substrate. A wiring, an interlayer insulating film, a switching element 21 and the like are formed on one main surface of the insulating substrate 20, and a color filter 22 is formed thereon. A pixel electrode 23 and a columnar spacer 27 are formed on the color filter 22, and the pixel electrode 23 is covered with an alignment film 24. A peripheral light shielding layer (or frame) 25 is formed around the color filter 22.

  Wirings formed on the insulating substrate 20 are gate lines, signal lines, auxiliary capacitance lines, and the like made of aluminum, molybdenum, copper, or the like. The switching element 21 is, for example, a TFT having amorphous silicon or polysilicon as a semiconductor layer and aluminum, molybdenum, chromium, copper, tantalum, or the like as a metal layer, and includes wiring such as gate lines and signal lines, and pixel electrodes. 23. With such a configuration, the array substrate 2 can selectively apply a voltage to a desired pixel electrode 23.

  The color filter 22 includes blue, green, and red colored layers 22B, 22G, and 22R. The color filter 22 is provided with a contact hole, and the pixel electrode 23 is connected to the switching element 21 through the contact hole. The colored layers 22B, 22G, and 22R can be formed using a photosensitive resin containing a colored dye or a colored pigment.

  As the material of the pixel electrode 23, for example, a transparent conductive material such as ITO (Indium Tin Oxide) can be used. The pixel electrode 23 can be formed by, for example, forming a thin film by a sputtering method or the like and then patterning the thin film using a photolithography technique and an etching technique.

  The pixel electrodes 23 are arranged in first and second directions that are substantially parallel to the main surface of the insulating substrate 20 and intersect each other. In this example, as shown in FIG. 3, the pixel electrodes 23 are arranged in a first direction D1 substantially perpendicular to the end face provided with the empty cell injection port and in a second direction D2 substantially parallel to the end face. is doing. The pixel electrodes 23 adjacent to each other in the first direction D1 form a slit SLT whose longitudinal direction is substantially parallel to the second direction D2.

  As shown in FIG. 3, each pixel electrode 23 has a shape in which a slit SLT is provided in a rectangle having a side parallel to the first direction D1 and a side parallel to the second direction D2. The slit SLT provided in each pixel electrode 23 forms a slit pattern. In this example, the slit SLT provided in each pixel electrode 23 has a longitudinal direction parallel to the second direction D2.

  The columnar spacer 27 is disposed adjacent to the pixel electrode 23. As the material of the columnar spacer 27, for example, the material of the colored layers 22B, 22G, and 22R or the material of the peripheral light shielding layer 25 can be used. When the material of the colored layers 22B, 22G, and 22R is used as the material of the columnar spacer 27, for example, two or more of the colored layers 22B, 22G, and 22R may be partially overlapped. If it carries out like this, the overlapping part of these colored layers 22B, 22G, and 22R can be utilized as at least one part of the columnar spacer 27. FIG. When the material of the peripheral light shielding layer 25 is used as the material of the columnar spacer 27, the columnar spacer 27 and the peripheral light shielding layer 25 may be formed at the same time.

  The alignment film 24 formed on the pixel electrode 23 is composed of a thin film made of a transparent resin such as polyimide. As will be described in detail later, when no voltage is applied to the alignment film 24 between the pixel electrode 23 and the common electrode 33 (hereinafter referred to as no voltage application), the liquid crystal molecules LC are shown in FIG. Or an alignment treatment for aligning in the direction indicated by the arrow AR in FIG. For example, the alignment film 24 is rubbed in the direction indicated by the arrow AR. Note that the direction indicated by the arrow AR is substantially perpendicular to the longitudinal direction of the slit SLT.

  The peripheral light shielding layer 25 surrounds the color filter 22. The peripheral light shielding layer 25 can be formed using a photosensitive resin containing a coloring dye or a coloring pigment.

  As shown in FIG. 2, the counter substrate 3 includes an insulating substrate 30 having optical transparency such as a glass substrate as a second substrate. On one main surface of the insulating substrate 30, a common electrode 33 that is a counter electrode and an alignment film 34 are sequentially formed.

  The common electrode 33 is formed as a continuous film facing all the pixel electrodes 23. As a material of the pixel electrode 23, for example, a transparent conductive material such as ITO can be used.

  The alignment film 34 is composed of a thin film made of a transparent resin such as polyimide. This alignment film 34 is given vertical alignment without being subjected to alignment treatment such as rubbing treatment.

  In this liquid crystal display device 1, each pixel region, which is a region sandwiched between the pixel electrode 23 and the counter electrode 33 in the liquid crystal layer, is arranged in the tilt direction (tilt alignment) of the liquid crystal molecules LC as shown in FIGS. 4 and 5. The director viewed from the direction perpendicular to the display surface of the liquid crystal molecules LC is divided into a plurality of different domains. 4 and 5, the alternate long and short dash line indicates a part of the boundary between domains. The other part of the boundary between the domains is at a position corresponding to the slit SLT of the liquid crystal layer.

  In this embodiment, the alignment division structure for generating these domains is provided only on the array substrate 2 and not on the counter substrate 3. Therefore, even when the array substrate 2 and the counter substrate 3 are bonded with a relatively low alignment accuracy, a sufficient viewing angle compensation effect can be obtained.

  In this embodiment, the alignment film 24 is subjected to an alignment process. Specifically, in the alignment film 24, when no voltage is applied, the liquid crystal molecules LC positioned in the vicinity of the alignment film 24 intersect with the longitudinal direction of the slit SLT that is the alignment division structure, for example, the longitudinal direction of the slit SLT. An alignment process is performed to align in a direction substantially perpendicular to the direction. In other words, in the alignment film 24, when no voltage is applied, the liquid crystal molecules LC positioned in the vicinity of the alignment film 24 intersect the boundary between domains indicated by broken lines in FIGS. An alignment process is performed to align in a direction substantially perpendicular to the boundary between them.

  In this way, the boundaries between the domains become clear and as a result, the transmittance is improved. This will be described with reference to FIGS.

  6 and 7 are perspective views schematically showing a liquid crystal display device according to a comparative example. FIG. 8 is a perspective view schematically showing the liquid crystal display device of FIG.

  In the liquid crystal display device 1 of FIG. 6, the alignment film 24 covering the pixel electrode 23 is a vertical alignment film, and is between the counter electrode 33 and the alignment film 34 and is indicated by a one-dot chain line in FIGS. 4 and 5. The liquid crystal display device 1 has the same structure as that of the liquid crystal display device 1 shown in FIG. 1 except that a bowl-shaped dielectric pattern 36 is disposed along the boundary between domains. The liquid crystal display device 1 of FIG. 7 has the same structure as the liquid crystal display device 1 of FIG. 1 except that the alignment film 24 covering the pixel electrode 23 is a vertical alignment film.

  6 to 8, some components are omitted for simplification. For example, in FIG. 6, the pixel electrode 23 of the array substrate 2, the dielectric pattern 36 of the counter substrate, and the liquid crystal molecules LC are drawn, and other components are omitted. 7 and 8, the pixel electrodes 23 and the liquid crystal molecules LC of the array substrate 2 are drawn, and other components are omitted.

  When performing display with the liquid crystal display device 1 of FIGS. 6 to 8, for example, the voltage applied between the pixel electrode 23 and the common electrode 33 is a first voltage having a smaller absolute value and an absolute value smaller than this. Change between large second voltages. Thus, the liquid crystal molecules LC change the tilt angle while maintaining the tilt direction, and accordingly, the refractive index of the liquid crystal layer changes. In the liquid crystal display device 1 shown in FIGS. 6 to 8, display is performed using this change in refractive index.

  In the liquid crystal display device 1 of FIGS. 6 to 8, when a first voltage having a small absolute value is applied between the pixel electrode 23 and the common electrode 33, an electric field is formed in the liquid crystal material 5. Since the liquid crystal material 5 has a negative dielectric anisotropy, a force is applied to the liquid crystal molecules LC to align them perpendicularly to the lines of electric force.

  In the upper part of the slit SLT, the lines of electric force are inclined without being perpendicular to the main surfaces of the pixel electrode 23 and the common electrode 33, for example, as indicated by broken lines in FIGS. Therefore, in the vicinity of the slit SLT, a force for aligning the liquid crystal molecules LC perpendicularly to the oblique lines of electric force is applied.

  In the liquid crystal display device 1 of FIG. 6, a dielectric pattern 36 is disposed between the common electrode 33 and the alignment film 34. Below the dielectric pattern 36, the lines of electric force are not perpendicular to the main surfaces of the pixel electrode 23 and the common electrode 33 but are inclined.

  In addition, in the liquid crystal display device 1 of FIG. 6, the alignment film 34 covering the common electrode 33 is a vertical alignment film. Since the dielectric pattern 36 generates a ridge-shaped convex portion on the surface of the alignment film 34, the alignment film 34 causes the liquid crystal molecules LC in the vicinity of the ridge-shaped convex portion to be a surface substantially perpendicular to the longitudinal direction of the dielectric pattern 36. Try to tilt inside.

  As a result, each pixel region corresponding to the pixel electrode 23 in the liquid crystal layer is divided into a plurality of domains in which the tilt directions of the liquid crystal molecules LC are different from each other with the slit SLT and the dielectric pattern 36 as boundaries as shown in FIG. Divided. That is, in the liquid crystal display device 1 of FIG. 6, the boundary between domains is clear and high transmittance can be obtained.

  In the liquid crystal display device 1 of FIG. 7, unlike the liquid crystal display device 1 of FIG. 6, the dielectric pattern 36 is not disposed between the common electrode 33 and the alignment film 34. Therefore, the liquid crystal display device 1 of FIG. 7 has a weaker ability to suppress the rotation of the liquid crystal molecules LC in the direction indicated by the double arrows than the liquid crystal display device 1 of FIG.

  Therefore, in the liquid crystal display device 1 of FIG. 7, if the dielectric pattern 36 is omitted, the boundary between domains at a position away from the slit SLT, that is, the boundary indicated by the alternate long and short dash line is unclear. In other words, in the liquid crystal display device 1 in FIG. 7, the tilt direction of the liquid crystal molecules LC deviates from the design range in a larger region as compared with the liquid crystal display device 1 in FIG. 6. Therefore, in the liquid crystal display device 1 of FIG. 7, the transmittance as high as that of the liquid crystal display device 1 of FIG. 6 cannot be obtained.

  In the liquid crystal display device 1 of FIG. 8, unlike the liquid crystal display device 1 of FIGS. 6 and 7, a vertical alignment film is not used as the alignment film 24, and the liquid crystal molecules LC are indicated by arrows AR when no voltage is applied. Those that are oriented parallel to the direction are used. Therefore, the rotation of the liquid crystal molecules LC indicated by the double arrows in FIG. 7 is unlikely to occur in the liquid crystal display device 1 of FIG. Therefore, in the liquid crystal display device 1 of FIG. 8, although the dielectric pattern 36 is not provided, a boundary between domains indicated by a one-dot chain line can be clearly generated at a position away from the slit SLT. Therefore, the liquid crystal display device 1 of FIG. 8 can achieve higher transmittance than the liquid crystal display device 1 of FIG.

Next, the second aspect of the present invention will be described.
FIG. 9 is an enlarged plan view showing the liquid crystal display device according to the second embodiment of the present invention. FIG. 10 is an enlarged plan view showing the liquid crystal display device according to the second embodiment of the present invention. FIG. 11 is a cross-sectional view of the liquid crystal display device shown in FIGS. 9 and 10 along the line XI-XI.

  9 to 11, some components are omitted for simplification. For example, in FIG. 9, pixel electrodes and dielectric patterns of the array substrate are drawn, and other components are omitted. In FIG. 10, pixel electrodes and dielectric patterns of the array substrate and liquid crystal molecules are drawn, and other components are omitted. In FIG. 11, switching elements, color filters, polarizing plates, and the like are omitted.

The liquid crystal display device 1 shown in FIGS. 9 to 11 has the same structure as the liquid crystal display device 1 according to the first aspect except that the following structure is adopted for the array substrate 2. That is, in the liquid crystal display device 1, the pixel electrode 23 is not provided with the slit SLT. Instead, a bowl-shaped dielectric pattern 26 is disposed between the pixel electrode 23 and the alignment film 24. Examples of the material of the dielectric pattern 26 include organic dielectrics such as acrylic resin, epoxy resin, novolac resin, polyimide resin, and polymer liquid crystal, and inorganic dielectrics such as SiO ₂ , SiN _x , and Al ₂ O _3. Can be used.

  In the liquid crystal display device 1 of FIGS. 9 to 11, when a first voltage having a small absolute value is applied between the pixel electrode 23 and the common electrode 33, an electric field is formed in the liquid crystal material 5. Since the liquid crystal material 5 has a negative dielectric anisotropy, a force is applied to the liquid crystal molecules LC to align them perpendicularly to the lines of electric force.

  In the upper part of the slit SLT, the lines of electric force are inclined without being perpendicular to the main surfaces of the pixel electrode 23 and the common electrode 33, for example, as indicated by a broken line in FIG. Therefore, in the vicinity of the slit SLT, a force for aligning the liquid crystal molecules LC perpendicularly to the oblique lines of electric force is applied.

  Even in the upper part of the dielectric pattern 26, the lines of electric force are not perpendicular to the main surfaces of the pixel electrode 23 and the common electrode 33, for example, as indicated by broken lines in FIG. 11. Therefore, even in the vicinity of the dielectric pattern 26, a force for aligning the liquid crystal molecules LC perpendicularly to the oblique lines of electric force is applied.

  In the liquid crystal display device 1 of FIGS. 9 to 11, the alignment film 24 is subjected to an alignment process for aligning the liquid crystal molecules LC in the direction indicated by the arrow AR in FIG. 9 when no voltage is applied. Therefore, in the liquid crystal display device 1 of FIGS. 9 to 11, the alignment film 24 restricts the tilt direction of the liquid crystal molecules LC to a direction parallel to the direction indicated by the arrow AR.

  Therefore, in the liquid crystal display device 1 of FIGS. 9 to 11, even though the alignment substrate is not provided on the counter substrate 3, between the domains indicated by the alternate long and short dash lines at positions away from the dielectric pattern 26 and the slit SLT. A boundary can be clearly generated. Therefore, also in this aspect, the same effect as described in the first aspect can be obtained.

Next, the third aspect of the present invention will be described.
FIG. 12 is an enlarged plan view showing the liquid crystal display device according to the third aspect of the present invention. 13 is a cross-sectional view taken along line XIII-XIII of the liquid crystal display device shown in FIG.

  12 and 13, some components are omitted for simplification. For example, in FIG. 12, pixel electrodes and alignment films of the array substrate and liquid crystal molecules are drawn, and other components are omitted. In FIG. 13, a switching element, a color filter, a polarizing plate, and the like are omitted.

  The liquid crystal display device 1 shown in FIG. 12 and FIG. 13 has the same structure as the liquid crystal display device 1 according to the first aspect except that the following structure is adopted for the array substrate 2. That is, in the liquid crystal display device 1, the alignment film 24 covering the pixel electrode 23 is constituted by the first portion 24a and the second portion 24b.

  Each of the first portion 24a and the second portion 24b has a strip shape substantially parallel to the longitudinal direction of the slit SLT. The first portions 24a and the second portions 24b are alternately arranged in the direction indicated by the arrow AR.

  In FIG. 12, the boundary between the first portion 24a and the second portion 24b is at the position indicated by the alternate long and short dash line and the broken line. That is, the first portion 24a and the second portion 24b face the domains arranged in the direction indicated by the arrow AR, respectively.

  The first portion 24a is subjected to an alignment treatment in which the liquid crystal molecules LC on the first portion 24a are tilted in the direction indicated by the arrow AR when no voltage is applied. For example, the first portion 24a is rubbed in the direction indicated by the arrow AR.

  In the second portion 24b, when no voltage is applied, the liquid crystal molecules LC on the second portion 24b are aligned in the direction indicated by the arrow AR with a smaller pretilt angle than the liquid crystal molecules LC on the first portion 24a. An orientation treatment is performed. For example, the second portion 24b is rubbed in the direction indicated by the arrow AR, and further irradiated with ultraviolet rays. As the ultraviolet rays, for example, linearly polarized light whose polarization direction is parallel to the direction indicated by the arrow AR is used. Further, the rubbing process for the first portion 24a and the rubbing process for the second portion 24b can be performed simultaneously.

  The alignment film 24 subjected to such alignment treatment regulates the tilt direction of the liquid crystal molecules LC in a direction parallel to the direction indicated by the arrow AR. Therefore, in the liquid crystal display device 1 of FIGS. 12 and 13, the boundary between domains indicated by the alternate long and short dash line is clearly generated at a position away from the slit SLT, although the alignment substrate is not provided on the counter substrate 3. Can be made. Therefore, also in this aspect, the same effect as described in the first aspect can be obtained.

Next, the fourth aspect of the present invention will be described.
FIG. 14 is an enlarged plan view showing the liquid crystal display device according to the fourth embodiment of the present invention. 15 is a cross-sectional view taken along line XV-XV of the liquid crystal display device shown in FIG.

  14 and 15, some components are omitted for simplification. For example, in FIG. 14, the pixel electrodes, the dielectric pattern, the alignment film, and the liquid crystal molecules of the array substrate are drawn, and other components are omitted. In FIG. 15, switching elements, color filters, polarizing plates, and the like are omitted.

  The liquid crystal display device 1 shown in FIGS. 14 and 15 has the same structure as the liquid crystal display device 1 according to the second aspect except that the following structure is adopted for the array substrate 2. That is, in the liquid crystal display device 1, the structure described in the third embodiment is adopted for the alignment film 24 covering the pixel electrode 23.

  In the liquid crystal display device 1, the boundary between the domains indicated by the alternate long and short dash line can be clearly generated at a position away from the slit SLT even though the counter substrate 3 is not provided with the alignment division structure. Therefore, also in this aspect, the same effect as described in the first aspect can be obtained.

Examples of the present invention will be described below.
Example 1
In this example, the liquid crystal display device 1 shown in FIGS. 1 to 5 was manufactured by the method described below.

  First, film formation and patterning were repeated in the same manner as a normal array substrate formation process, and various wirings, TFTs 21 and the like were formed on the glass substrate 20. Next, a color filter 22 was formed by a conventional method on the surface of the glass substrate 20 on which the TFTs 21 and the like were formed. At this time, the colored layers 22 </ b> B, 22 </ b> G, and 22 </ b> R were partially overlapped, and the overlapping portion was used as the columnar spacer 27.

  Next, ITO was sputtered onto the color filter 22 through a mask having a predetermined pattern. Thereafter, a resist pattern was formed on the ITO film, and the exposed portion of the ITO film was etched using the resist pattern as a mask. As described above, the pixel electrode 23 shown in FIGS. 2 to 5 was formed.

  Next, the photosensitive resin containing a black pigment was apply | coated to the surface in which the pixel electrode 23 of the glass substrate 20 was formed using the spinner. After drying this coating film, pattern exposure using ultraviolet rays, development using an aqueous alkaline solution, and baking were sequentially performed. Thereby, the peripheral light shielding layer 25 of FIG. 2 was obtained.

  Thereafter, a thermosetting resin was applied to the entire surface of the glass substrate 20 on which the pixel electrodes 23 were formed. After the coating film was baked, a rubbing process was performed in the direction indicated by the arrow AR in FIGS. 3 to 5 to form an alignment film 24 having a thickness of 70 nm. The array substrate 2 was produced as described above.

  Next, an ITO film was formed as a common electrode 33 on one main surface of a separately prepared glass substrate 30 by a sputtering method. Next, a thermosetting resin was applied onto the common electrode 33, and this coating film was baked to form a vertical alignment film 34. The counter substrate 3 was produced as described above.

  Next, the array substrate 2 and the peripheral portion of the counter surface of the counter substrate 3 were bonded together using an epoxy thermosetting resin 4 to form an empty cell. A nematic liquid crystal material 5 having a negative dielectric anisotropy was injected into this empty cell.

  Thereafter, the injection port was closed with the ultraviolet curable resin 6, and the polarizing plate 7 was attached to the outer surfaces of the array substrate 2 and the counter substrate 3. As described above, the liquid crystal display device 1 shown in FIGS. 1 to 5 was completed.

  Next, the display characteristics of the liquid crystal display device 1 were examined. As a result, the transmittance of the liquid crystal display device 1 was 7.2%.

(Comparative example)
In this example, the liquid crystal display device 1 was manufactured by the same method as that described in Example 1 except that the alignment film 24 was not rubbed. That is, in this example, the alignment film 24 is a vertical alignment film.
The display characteristics of the liquid crystal display device 1 were examined. As a result, the transmittance of the liquid crystal display device 1 was 5.6%.

(Example 2)
In this example, the liquid crystal display device 1 shown in FIGS. 9 to 11 was manufactured. Specifically, the liquid crystal display device 1 shown in FIGS. 9 to 11 is formed by the same method as that described in Example 1 except that the dielectric pattern 26 is formed at the same time as the peripheral light shielding layer 25 is formed. Was made.
The display characteristics of the liquid crystal display device 1 were examined. As a result, the transmittance of the liquid crystal display device 1 was 7.4%.

(Example 3)
In this example, the liquid crystal display device 1 shown in FIGS. 12 and 13 was produced. Specifically, the same method as described in Example 1 except that a part of the alignment film 24 is irradiated with ultraviolet rays to generate the first part 24a and the second part 24b in the alignment film 24. Thus, the liquid crystal display device 1 shown in FIGS. 12 and 13 was produced.
The display characteristics of the liquid crystal display device 1 were examined. As a result, the transmittance of the liquid crystal display device 1 was 6.9%.

1 is a plan view schematically showing a liquid crystal display device according to a first embodiment of the present invention. Sectional drawing along the II-II line of the liquid crystal display device shown in FIG. FIG. 2 is an enlarged plan view showing the liquid crystal display device of FIG. 1. FIG. 2 is an enlarged plan view showing the liquid crystal display device of FIG. 1. Sectional drawing along the VV line of the liquid crystal display device shown in FIG.3 and FIG.4. The perspective view which shows schematically the liquid crystal display device which concerns on a comparative example. The perspective view which shows schematically the liquid crystal display device which concerns on a comparative example. FIG. 2 is a perspective view schematically showing the liquid crystal display device of FIG. 1. The top view which expands and shows the liquid crystal display device which concerns on the 2nd aspect of this invention. The top view which expands and shows further the liquid crystal display device which concerns on the 2nd aspect of this invention. Sectional drawing along the XI-XI line of the liquid crystal display device shown in FIG.9 and FIG.10. The top view which expands and shows the liquid crystal display device which concerns on the 3rd aspect of this invention. Sectional drawing along the XIII-XIII line of the liquid crystal display device shown in FIG. The top view which expands and shows the liquid crystal display device which concerns on the 4th aspect of this invention. FIG. 15 is a sectional view taken along line XV-XV of the liquid crystal display device shown in FIG. 14.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Liquid crystal display device, 2 ... Array substrate, 3 ... Opposite substrate, 4 ... Adhesive layer, 5 ... Liquid crystal material, 6 ... Sealing body, 7 ... Polarizing plate, 8 ... Signal line drive circuit, 9 ... Scanning line drive Circuit 20... First substrate 21. Switching element 22. Color filter 22 B Colored layer 22 G Colored layer 22 R Colored layer 23 Pixel electrode 24 Oriented film 24 a First part 24 b 2nd part, 25 ... Peripheral light shielding layer, 26 ... Dielectric pattern, 30 ... 2nd substrate, 33 ... Counter electrode, 34 ... Orientation film, 36 ... Dielectric pattern, AR ... Arrow, D1 ... 1st direction, D2 ... 2nd direction, LC ... Liquid crystal molecule, SLT ... Slit.

Claims (5)

An array substrate comprising: a first substrate; a plurality of pixel electrodes arranged on one main surface thereof; and a first alignment film covering the plurality of pixel electrodes;
A counter provided with a second substrate facing the first alignment film, a counter electrode provided on a surface facing the array substrate, and a second alignment film that is a vertical alignment film covering the counter electrode A substrate,
A liquid crystal layer interposed between the array substrate and the counter substrate and containing a liquid crystal material having a negative dielectric anisotropy;
Of the array substrate and the counter substrate, only the array substrate is sandwiched between the pixel electrode and the counter electrode of the liquid crystal layer when a voltage is applied between the pixel electrode and the counter electrode. An alignment division structure is provided that divides each pixel area, which is a divided area, into a plurality of domains having different tilt directions of liquid crystal molecules,
The alignment division structure is a dielectric pattern disposed between a slit provided in the pixel electrode and / or the pixel electrode and the first alignment film,
The first alignment film crosses the liquid crystal molecules in the vicinity of the first alignment film with the longitudinal direction of the alignment division structure when no voltage is applied between the pixel electrode and the counter electrode. A liquid crystal display device, characterized by being subjected to an alignment treatment for aligning in a direction to be aligned.   The liquid crystal display device according to claim 1, wherein the first alignment film is rubbed. In each of the pixel regions, the plurality of domains include first and second domains adjacent to each other in the rubbing direction of the first alignment film,
The first portion of the first alignment layer facing the first domain tilts the liquid crystal molecules on the first portion in the rubbing direction when the voltage is not applied.
The second portion of the first alignment film facing the second domain has the liquid crystal molecules on the second portion in the rubbing direction and the liquid crystal molecules on the first portion when the voltage is not applied. The liquid crystal display device according to claim 2, wherein the liquid crystal display device is aligned with a smaller pretilt angle.   The liquid crystal display device according to claim 1, wherein the array substrate further includes a color filter between the first substrate and the plurality of pixel electrodes.   The liquid crystal display device according to claim 1, wherein the array substrate further includes a columnar spacer supported on a surface of the first substrate facing the counter substrate.

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