JP2007199239A - Liquid crystal device, manufacturing method therefor and electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a VA mode liquid crystal device wherein the viewing angle characteristics are improved, while using a simple structure. <P>SOLUTION: In the liquid crystal device, a liquid crystal layer 50, comprising a liquid crystal having negative dielectric anisotropy, is interposed between a pair of substrates 10 and 20, disposed opposite to each other; alignment layers 18 and 28 regulating the liquid crystal in the vertical direction are, respectively provided on the liquid crystal layer 50 side of the substrates 10 and 20; and the alignment layer 18 has a plurality of alignment regions 18a and 18b, having different alignment regulating force with respect to the liquid crystal in one sub pixel to be an image display unit. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid crystal device, a manufacturing method thereof, and an electronic apparatus.

Currently, as one method for realizing wide viewing angle characteristics, a VA (Vertical Alignment) mode is known in which a liquid crystal having negative dielectric anisotropy is aligned perpendicularly to a substrate and is aligned in the direction of the substrate surface by applying a voltage. Yes. With this technique, wide viewing angle can be realized by an MVA (Multi-domain Vertical Alignment) method in which the liquid crystal is aligned in four directions with reference to a nucleus formed by a protrusion or slit structure (see, for example, Patent Document 1). According to this method, a far wider viewing angle can be realized in all directions than in the conventional liquid crystal mode (TN mode or the like), but the problem is that the γ characteristic when observed from an oblique direction is significantly different from the front. Yes. As a method for solving this problem, there is a method of improving the viewing angle characteristics by providing two drive elements in one pixel and forming a plurality of domains in the pixel with different applied voltages by each drive element (non-non-uniform). Patent Document 1). Alternatively, there is a method in which a dielectric film is partially formed in one pixel, and domains having different applied voltages are formed in the pixel by using a voltage drop of the dielectric film (see Non-Patent Document 2).
JP 2000-47251 A "The World's Largest (82-in.) TFT-LCD", Sang Soo Kim, 2005 / SID DIGEST 66.1, p1842-1847 "Multi-Domain Vertically Aligned LCDs with Super-Wide Viewing Range for Glay-Scale Images", H. Yoshida et al., Asia display Digest 12-2

  However, in the technique described in Non-Patent Document 1, since it is necessary to mount twice as many driving elements as usual, driving becomes complicated and pixel design becomes complicated. In the technique described in Non-Patent Document 2, since a dielectric film is partially provided on the electrode, there are restrictions on cell gap control and selection of a material for the dielectric film.

  The present invention has been made in view of the above-described problems of the prior art, and an object thereof is to provide a VA mode liquid crystal device having improved viewing angle characteristics while using a simple structure, and a method for manufacturing the same.

  The liquid crystal device of the present invention includes a liquid crystal layer composed of a liquid crystal having negative dielectric anisotropy between a pair of substrates arranged opposite to each other, and the liquid crystal is disposed on the liquid crystal layer side of each substrate. Each of the alignment films that are vertically regulated is provided, and at least one of the alignment films has a plurality of alignment regions having different alignment regulating forces with respect to the liquid crystal in one pixel region serving as an image display unit. It is characterized by. Thus, by setting it as the structure which provided the several orientation area | region in 1 pixel area | region used as an image display unit, the several area | region where electro-optical characteristics differ in the said pixel area based on the difference of the said orientation control force is provided. Can be formed. As a result, since the pixel display is formed by liquid crystals having different alignment states in both the front view and the perspective view, it is possible to suppress the difference in γ characteristics between the front view and the perspective view, and to have an excellent viewing angle characteristic. It will be obtained. In the entire pixel area, an electro-optical characteristic obtained by averaging the electro-optical characteristics of the plurality of areas can be obtained.

  The liquid crystal device of the present invention is characterized in that each of the alignment films facing each other with the liquid crystal layer interposed therebetween has the plurality of alignment regions. With such a configuration, the difference in the electro-optical characteristics can be made more prominent, and the effect of suppressing the difference in γ characteristics between the front view and the perspective view can be enhanced.

  The liquid crystal device according to the present invention is characterized in that the alignment regions facing each other with the liquid crystal layer interposed therebetween have the same alignment regulating force. With such a configuration, it is possible to prevent the liquid crystal from exhibiting different behaviors for each pixel region, and it is possible to prevent the occurrence of display unevenness.

  In the liquid crystal device of the present invention, the alignment film is formed using different alignment film materials for each alignment region. According to this configuration, it is possible to easily form a plurality of alignment regions having different alignment regulating forces by a simple process.

  In the liquid crystal device according to the aspect of the invention, the alignment film includes a first alignment film formed to cover the substrate and a second alignment film partially formed on the first alignment film. It is characterized by that. With such a configuration, the alignment film can be formed by a simpler process.

  In the liquid crystal device of the present invention, a pair of electrodes facing each other with the liquid crystal layer interposed therebetween is provided on each substrate, and at least one of the pair of electrodes includes a plurality of electrodes in the one pixel region when a selection voltage is applied. An alignment control means for forming a liquid crystal region is provided, and the alignment region is arranged corresponding to one or a plurality of the liquid crystal regions. By adopting such a configuration, it is possible to prevent the behavior of liquid crystal molecules from being different at the time of applying a selection voltage for each liquid crystal region, and it is possible to prevent display unevenness.

  In the liquid crystal device of the present invention, a pixel electrode including a plurality of island-shaped portions and a connecting portion that electrically connects the island-shaped portions is provided on the substrate, and the plurality of alignment regions include: Each of them is arranged corresponding to the planar area of the island-shaped part. With such a configuration, the alignment region can be arranged for each liquid crystal region formed corresponding to the island-like portion, and a structure in which display unevenness is unlikely to occur can be obtained.

  In the liquid crystal device of the present invention, a pixel electrode including a plurality of island-like portions and a connecting portion that electrically connects the island-like portions is provided on the substrate, and a planar region of the island-like portion is provided. A plurality of the alignment regions are arranged therein. With such a configuration, the viewing angle characteristics can be improved for each liquid crystal region formed by the island-shaped portions, and a liquid crystal device capable of obtaining excellent viewing angle characteristics regardless of the viewing direction can be obtained. .

  In the liquid crystal device of the present invention, a transmissive display region and a reflective display region are partitioned in the one pixel region, and the transmissive display region or the reflective display region has a plurality of alignments having different alignment regulating forces. A region is arranged. With such a configuration, it is possible to obtain a transflective liquid crystal device that achieves improved viewing angle characteristics in transmissive display and / or reflective display.

  The liquid crystal device of the present invention is characterized in that a plurality of alignment regions having different alignment regulating forces are arranged in the transmissive display region. With such a configuration, it is possible to improve the viewing angle characteristics of transmissive display, which is particularly important in a transflective liquid crystal device, and it is possible to provide a liquid crystal device with excellent display quality at low cost.

  The manufacturing method of the liquid crystal device of the present invention is the manufacturing method of the liquid crystal device described above, wherein the alignment film formed on the substrate is selectively irradiated with light through a mask. A plurality of alignment regions having different alignment regulating forces with respect to the liquid crystal are partitioned.

  The method for manufacturing a liquid crystal device according to the present invention is the method for manufacturing a liquid crystal device described above, wherein different types of alignment film materials are selectively disposed on the substrate by using a droplet discharge method, and alignment control is performed. The alignment film having a plurality of alignment regions having different forces is formed.

  The method for manufacturing a liquid crystal device according to the present invention is the method for manufacturing a liquid crystal device described above, wherein a step of forming a first alignment film on the substrate, and a photosensitive alignment film material on the first alignment film And a step of forming a coating film, and a step of forming a second alignment film by partially removing the coating film by exposure and development treatment.

  An electronic apparatus according to the present invention includes the liquid crystal device described above. According to this configuration, it is possible to provide an electronic apparatus including a display unit having a high contrast and a wide viewing angle.

(First embodiment)
Hereinafter, a liquid crystal device according to a first embodiment of the present invention will be described with reference to the drawings.
The liquid crystal device according to the present embodiment is a VAN (Vertical Aligned Nematic) that displays an image by applying an electric field to a liquid crystal having a negative dielectric anisotropy aligned perpendicularly to a substrate surface and controlling the alignment. ) Mode active matrix liquid crystal device, which is a transmissive liquid crystal device that performs display using light supplied from a backlight disposed on the back side of the panel. The liquid crystal device according to the present embodiment can perform color display using a color filter provided on the substrate, and outputs three color lights of R (red), G (green), and B (blue). One pixel constitutes one pixel. Therefore, in this specification, a display region that is a minimum unit constituting a display is referred to as a “sub-pixel”. A display area composed of a set (R, G, B) of sub-pixels is referred to as a “pixel”.
In the drawings referred to in each embodiment, each layer and each member are displayed in different scales so that each layer and each member have a size that can be recognized on the drawing.

  FIG. 1 is a circuit configuration diagram of a plurality of sub-pixels formed in a matrix that constitutes the liquid crystal device of the present embodiment. FIG. 2 is a diagram showing a planar configuration of the TFT array substrate in an arbitrary subpixel of the liquid crystal device 100. FIG. FIG. 3 is a partial cross-sectional configuration diagram of the liquid crystal device 100 taken along the line DD ′ of FIG.

  As shown in FIG. 1, the image display area of the liquid crystal device 100 has a plurality of subpixels Sp arranged in a matrix. Each subpixel Sp is formed with a pixel electrode 9 and a TFT 30 for controlling the switching of the pixel electrode 9, and a data line 6 a extending from the data line driving circuit 101 serving as a pixel driving unit is electrically connected to the source of the TFT 30. Connected. The data line driving circuit 101 supplies the image signals S1, S2,..., Sn to each pixel via the data line 6a. The image signals S1 to Sn may be supplied line-sequentially in this order, or may be supplied for each group to a plurality of adjacent data lines 6a. A scanning line 3a extending from the scanning line driving circuit 102 which is a pixel driving unit is electrically connected to the gate of the TFT 30, and is supplied in a pulsed manner from the scanning line driving circuit 102 to the scanning line 3a at a predetermined timing. The scanning signals G1, G2,..., Gm are applied to the gate of the TFT 30 in the order of lines in this order. The pixel electrode 9 is electrically connected to the drain of the TFT 30. The TFT 30 serving as a switching element is turned on for a certain period by the input of scanning signals G1, G2,..., Gm, so that the image signals S1, S2,. Writing is performed on the pixel electrode 9.

  Image signals S1, S2,..., Sn written to the liquid crystal via the pixel electrode 9 are held for a certain period between the pixel electrode 9 and the common electrode opposed via the liquid crystal. Here, in order to prevent the held image signal from leaking, a storage capacitor 70 is connected in parallel with the liquid crystal capacitor formed between the pixel electrode 9 and the common electrode. The storage capacitor 70 is provided between the drain of the TFT 30 and the capacitor line 3b.

Next, a detailed configuration of the liquid crystal device 100 will be described with reference to FIGS.
The liquid crystal device 100 has a configuration in which a liquid crystal layer 50 is sandwiched between a TFT array substrate (first substrate) 10 and a counter substrate (second substrate) 20 as shown in FIG. The substrate 10 and the counter substrate 20 are sealed between the substrates 10 and 20 by a seal material (not shown) provided along an edge of a region where the substrate 10 and the counter substrate 20 face each other. A backlight (illuminating device) 90 including a light guide plate 61 and a reflective plate 62 is disposed on the back side (the lower side in the drawing) of the counter substrate 20.

As shown in the plan view of FIG. 2, the sub-pixel of the liquid crystal device 100 is provided with a pixel electrode 9 and a TFT 30 that is a pixel switching element. A plurality of scanning lines 3a extending along the longitudinal direction (Y-axis direction) of the pixel electrode 9 and data lines 6a extending along the short direction (X-axis direction) of the pixel electrode 9 are formed. The line 6a and the scanning line 3a are electrically connected to the TFT 30 in the vicinity of the intersection.
Further, although omitted in FIG. 2, a color filter (color material layer) 22 of one of the three primary colors is formed corresponding to one subpixel, and adjacent to each other including the three color filters 22. The three sub-pixels arranged in this manner form one pixel. For example, the color filter 22 is formed in a stripe shape extending in the X-axis direction in the drawing for each color, and is formed across a plurality of subpixels in the extending direction, and is periodically arranged in the horizontal direction in the drawing. It has become.

  The pixel electrode 9 is made of a transparent conductive film such as ITO (indium tin oxide), and is roughly divided into two island-like portions 9a and 9b in each sub-pixel, and between the adjacent island-like portions 9a and 9b. It has the shape connected with the center part. Since the pixel electrodes in the portion connecting the island-like portions 9a and 9b are also made of a transparent conductive film such as ITO, this connecting portion also contributes to display. Dielectric protrusions 191 and 192, which are alignment control means for restricting the alignment of the liquid crystal, are disposed at substantially the central portions of the island-shaped portions 9a and 9b, respectively. The island-shaped portions 9a and 9b have a substantially octagonal shape with chamfered corners, but may have a curved shape with rounded corners.

  In the pixel electrode 9 shown in FIG. 2, a TFT 30 is interposed between the island-like portion 9a, the scanning line 3a, and the data line 6a on the left side in the figure. The TFT 30 includes a semiconductor layer 35, a gate electrode 32 provided on the lower layer side (substrate body 10 </ b> A side) of the semiconductor layer 35, and a source electrode 6 b and a drain electrode 31 provided on the upper layer side of the semiconductor layer 35. Yes. In this embodiment, the drain electrode 31 is formed of a strip-like conductive film having a width equivalent to that of the source electrode 6b. However, the drain electrode 31 is further extended and is positioned so as to overlap with the extended drain electrode. By disposing a capacitor line (or a capacitor electrode connected to the capacitor line), a storage capacitor of the subpixel can be formed.

  The gate electrode 32 is formed by branching a part of the scanning line 3a in the extending direction of the data line 6a, and is opposed to the semiconductor layer 35 via an insulating film (not shown) on the tip side. The source electrode 6b is formed by branching a part of the data line 6a in the extending direction of the scanning line 3a. The source electrode 6b is disposed so as to run on the semiconductor layer 35 and is electrically connected to the TFT 30. Similarly, the drain electrode 31 is also disposed so as to partially run over the semiconductor layer 35 and is electrically connected to the TFT 30.

  Then, the drain electrode 31 and the island-like portion 9a (pixel electrode 9) are electrically connected through a pixel contact hole 45 provided in the center at the end of the drain electrode 31 opposite to the semiconductor layer 35. ing. With such a configuration, the TFT 30 is turned on for a predetermined period by a gate signal input via the scanning line 3a, so that an image signal supplied via the data line 6a is output at a predetermined timing. It is possible to write on the LCD.

  On the other hand, when viewing the cross-sectional structure shown in FIG. 3, the liquid crystal device 100 includes a TFT array substrate 10 and a counter substrate 20 disposed to face the TFT array substrate 10, and the liquid crystal sandwiched between these substrates 10 and 20. The layer 50 is made of a liquid crystal having an initial alignment state of vertical alignment and a negative dielectric anisotropy (refractive index anisotropy Δn is 0.1, for example). In FIG. 3, a substantially rod-shaped ellipsoid denoted by reference numeral 51 conceptually indicates vertically aligned liquid crystal molecules.

  The TFT array substrate 10 has a substrate body 10A made of a translucent material such as quartz or glass as a base, and a gate electrode 32 (scanning line 3a) is formed on the inner surface side (liquid crystal layer side) of the substrate body 10A. . An insulating thin film (gate insulating film) 11 is formed so as to cover the gate electrode 32, and a semiconductor layer 35 made of an island-shaped amorphous silicon film or the like is formed at a position facing the gate electrode 32 on the insulating thin film 11. ing. Further, the source electrode 6 b and the drain electrode 31 are formed on the insulating thin film 11 so as to partially run over the semiconductor layer 35. Between the source electrode 6b and the semiconductor layer 35 and between the drain electrode 31 and the semiconductor layer 35, an n + silicon layer 35n that ohmic-joins the semiconductor layer 35 and the electrode is interposed.

  A first interlayer insulating film 12 is formed so as to cover the source electrode 6 b and the drain electrode 31, and a second interlayer insulating film 13 is formed so as to cover the first interlayer insulating film 12. The first interlayer insulating film 12 is an insulating film made of a silicon nitride film or the like that protects each conductive film constituting the TFT 30, and the second interlayer insulating film 13 planarizes the surface of the substrate body 10A on which the TFT 30 or the like is formed. It is an insulating film made of a transparent resin material having a function. A pixel electrode 9 made of a transparent conductive film such as ITO is formed on the second interlayer insulating film 13. A part of the pixel electrode 9 is formed in a contact hole 45 that penetrates through the first interlayer insulating film 12 and the second interlayer insulating film 13 and reaches the drain electrode 31. With this structure, the pixel electrode 9 and the drain electrode are formed. 31 is electrically connected. A vertical alignment film 18 such as polyimide is formed so as to cover the pixel electrode 9, and the initial alignment of the liquid crystal molecules 51 is aligned perpendicular to the substrate surface. A phase difference plate 16 and a polarizing plate 14 are laminated on the outer surface side of the substrate body 10A.

  As shown in FIGS. 2 and 3, the alignment film 18 is divided into two alignment regions 18a and 18b in the plane region of the sub-pixel. The alignment region 18 a is provided in a rectangular region denoted by reference symbol A in FIG. 2 and is disposed corresponding to one island-like portion 9 a of the pixel electrode 9. The other alignment region 18b is provided in a rectangular region denoted by reference numeral B in FIG. 2, and is disposed corresponding to the island-shaped portion 9b. In the case of this embodiment, the alignment regulating force on the liquid crystal in the alignment region 18a is weaker than that of the other alignment region 18b. For example, the alignment region 18a and the alignment region 18b are formed by patterning different alignment film materials. Thus, the alignment film 18 having the above function can be obtained.

  The counter substrate 20 has a substrate body 20A made of a translucent material such as quartz or glass as a base. A color filter 22 is provided on the inner surface side of the substrate body 20A. As described above, the color filter 22 has a stripe shape extending in the longitudinal direction of the sub-pixel (X-axis direction in FIG. 2), and a metal film is formed in the boundary region between the adjacent sub-pixels in the extending direction of each color filter 22. And a light shielding layer (black matrix) 22BM made of black resin or the like.

  A counter electrode 21 is formed on the color filter 22. The counter electrode 21 is a transparent conductive film made of flat solid ITO or the like, and provided with dielectric protrusions 191 and 192 that protrude toward the liquid crystal layer 50 at positions facing the pixel electrode 9 on the counter electrode 21. . Although the cross-sectional shape of the dielectric protrusions 191 and 192 is illustrated as a substantially triangular shape, it is actually formed in a gentle curved surface shape. Corresponding to each of the two island-like portions 9a and 9b of the pixel electrode 9, one dielectric protrusion 191 and 192 is disposed at a position facing the central portion.

  The dielectric protrusions 191 and 192 are made of a dielectric material such as resin and can be formed by photolithography using a mask. For example, dielectric protrusions 191 and 192 having a height of 1.2 μm and a diameter of 12 μm can be collectively formed using a novolac positive photoresist. As for the cross-sectional shapes of the dielectric protrusions 191 and 192, if the resist is developed and post-baked at about 220 ° C., the tip shape can be blunted to obtain a gentle protrusion shape. A vertical alignment film 28 made of polyimide or the like is formed so as to cover the counter electrode 21 and the dielectric protrusions 191, 192, and the initial alignment of the liquid crystal molecules 51 is aligned perpendicular to the substrate surface.

  In the present embodiment, the alignment film 28 on the counter substrate 20 side is also divided into an alignment region 28a and an alignment region 28b, and the alignment region 28a is aligned in the alignment film 18 on the TFT array substrate 10 side. The region 18a is formed in a region that overlaps in plan (region A in FIG. 2), and the other alignment region 28b is formed in a region that overlaps in plane with the alignment region 18b (region B in FIG. 2). The alignment region 28a and the alignment region 28b are alignment films having different alignment control forces, and the alignment control force in the alignment region 28a is weaker than the alignment control force in the alignment region 28b. The alignment film 28 can also be produced by patterning the alignment regions 28a and 28b using different alignment film materials.

  A phase difference plate 26 and a polarizing plate 24 are laminated on the outer surface side of the substrate body 20A. The polarizing plates 14 and 24 have a function of transmitting only linearly polarized light that vibrates in a specific direction. The retardation plates 16 and 26 are λ / 4 plates having a phase difference of approximately ¼ wavelength with respect to the wavelength of visible light. The transmission axis of the polarizing plates 14 and 24 and the slow axis of the retardation plates 16 and 26 are arranged at an angle of about 45 °, and the polarizing plate 14 and the retardation plate 16 and the polarizing plate 24 and the retardation plate are arranged. 26 and cooperate with each other to function as a circularly polarizing plate. With this circularly polarizing plate, linearly polarized light is converted into circularly polarized light and incident on the liquid crystal layer 50, while circularly polarized light emitted from the liquid crystal layer 50 can be converted into linearly polarized light and output. Further, the transmission axis of the polarizing plate 14 and the transmission axis of the polarizing plate 24 are arranged orthogonally, and the slow axis of the retardation film 16 is arranged orthogonally to the slow axis of the retardation film 26. As a configuration of the polarizing plate and the retardation plate, a “polarizing plate + λ / 4 plate configuration circular polarizing plate” is common, but a “polarizing plate + λ / 2 plate + λ / 4 plate configuration circular polarizing plate ( By using “broadband circularly polarizing plate”, the black display can be made more achromatic.

  In the liquid crystal device 100 configured as described above, the liquid crystal having negative dielectric anisotropy is aligned perpendicularly to the substrate surface, and the liquid crystal is aligned in the substrate surface direction by applying a voltage to perform light modulation. Therefore, there is little light leakage in black display, and high contrast display can be obtained. In addition, the alignment region 18a and the alignment region 18b having different alignment regulating forces, and the alignment region 28a and the alignment region 28b are provided in the plane region of the sub-pixel, so that the pixel electrode 9 and the counter electrode 21 are arranged. The alignment state of the liquid crystal when a voltage is applied to can be made different between the alignment regions 18a and 18b. FIG. 4 is a graph showing the electro-optical characteristics of the liquid crystal device when the alignment regulating force of the alignment film is varied. The TV curve indicated by the dotted line in FIG. 4 is an alignment having a relatively weak alignment regulating force. The electro-optical characteristics in the region A where the films (alignment regions 18a and 28a) are formed are shown, and the solid line TV curve indicates the alignment films (alignment regions 18b and 28b) having a relatively strong alignment regulating force. 2 shows electro-optical characteristics in a region B where is formed.

  As shown in FIG. 4, the regions A and B where the alignment films having different alignment regulating forces are formed have different electro-optical characteristics, and the region A corresponding to the alignment regions 18 a and 28 a having a weak alignment regulating force is more suitable. The rise of the transmittance with respect to voltage application is quick, and the inclination is large. Since the liquid crystal device 100 according to this embodiment includes the regions A and B exhibiting different electro-optical characteristics in one sub-pixel, the electro-optic obtained by averaging the regions A and B in the entire sub-pixel. Thus, the difference in the γ characteristic between the front view and the perspective view, which is a problem in the VAN mode liquid crystal device, can be alleviated and the viewing angle characteristic can be improved. Furthermore, in the present invention, since the effect of improving the viewing angle characteristic is obtained by a simple method of forming alignment regions having different alignment regulating forces in the sub-pixel, when a plurality of driving elements are provided in the sub-pixel. There is no problem of complication of the manufacturing process and driving method in the above, and difficulty of cell gap control when a dielectric film is partially formed in the sub-pixel.

  In the present embodiment, both the alignment films 18 and 28 are configured to have a plurality of alignment regions. However, as long as at least one alignment film is divided into a plurality of alignment regions, the above-described configuration is used. It is possible to obtain an operational effect.

  In the above embodiment, as a method for forming the alignment regions 18a and 18b and the alignment regions 28a and 28b, a method of patterning an alignment film using different alignment film materials has been described. In addition to a method for patterning an alignment film using a lithography method, a method for forming an alignment film using a droplet discharge method can also be applied. When patterning using a photolithography method, for example, after forming a planar solid first alignment film using a first alignment film material, a photosensitive alignment film material is applied onto the first alignment film, and then the first alignment film material is applied. A method of forming a second alignment film on the first alignment film by forming a two alignment film and partially exposing the second alignment film can be employed. Thereby, for example, the alignment film 18 in which the formation region of the first alignment film is the alignment region 18a and the formation region of the second alignment film is the alignment region 18b can be obtained.

  On the other hand, according to the droplet discharge method in which the droplets discharged from the droplet discharge head are arranged on the substrate, any liquid material can be selectively arranged at any position on the substrate. The alignment film using the material can be formed very easily, and the use efficiency of the material is remarkably increased as compared with the photolithography method, which is also economical.

  Of course, other formation methods may be adopted when forming the alignment films 18 and 28. For example, after forming an alignment film, the alignment regulating force of the alignment film is partially varied by a method of selectively irradiating the alignment film through a mask, and the alignment regulating force differs within the sub-pixel. An alignment region can be formed. The alignment films 18 and 28 are not limited to organic alignment film materials such as polyimide, and may be formed using an inorganic alignment film material such as silicon oxide. In the case of using an inorganic alignment film material, in addition to a method of forming the alignment regions 18a and 18b using different alignment film materials, surface treatment applied to the inorganic alignment film in order to increase the alignment regulating force The alignment regions 18a and 18b may be formed by partially applying the inner regions.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a plan configuration diagram of the TFT array substrate in an arbitrary sub-pixel of the liquid crystal device 200 of the present embodiment, and corresponds to FIG. 2 in the previous first embodiment. FIG. 6 is a cross-sectional configuration diagram of the liquid crystal device 200 taken along the line FF ′ of FIG. 5 and corresponds to FIG. 3 in the first embodiment.

  The liquid crystal device 200 of the present embodiment is characterized in that it includes an alignment film having a configuration different from that of the liquid crystal device 100 according to the first embodiment, and the other configurations are the same as those of the previous liquid crystal device 100. This is a mode transmissive liquid crystal device. Therefore, in the following, the configuration of the alignment film will be described in detail, and description of other configurations will be omitted as appropriate. 5 and 6, the same reference numerals are given to the same components as those in FIGS. 1 to 3.

  As shown in FIG. 5, in the liquid crystal device 200 of the present embodiment, the alignment film 18 formed so as to cover the pixel electrode 9 is divided into eight alignment regions in the plane region of one subpixel. ing. Specifically, the alignment region 18a having a relatively weak alignment regulating force and the alignment region 18b having a relatively strong alignment regulating force are alternately arranged in the X-axis direction and the Y-axis direction. In addition, four alignment regions are arranged corresponding to the two island-like portions 9a and 9b of the pixel electrode 9, and the corners where the four alignment regions 18a and 18b are close to each other are almost the same as the island-like portions 9a. The region A having a weak orientation regulating force and the region B having a strong orientation regulating force are arranged so as to be divided into four on the island-like portion 9a. Similarly, the alignment regions 18a and the alignment regions 18b are alternately arranged in the rotation direction around the center of the formation region of the island-shaped portion 9b.

  In the cross-sectional structure shown in FIG. 6, a plurality of alignments are formed on the surface of the counter substrate 20 facing the alignment film 18 having a plurality of alignment regions 18 a and 18 b formed on the TFT array substrate 10 and the liquid crystal layer 50 therebetween. An alignment film 28 having regions 28a and 28b is formed. The plurality of alignment regions 28a and 28b constituting the alignment film 28 are provided corresponding to the alignment regions 18a and 18b of the alignment film 18, respectively. The alignment region 28a having a relatively weak alignment regulating force is the alignment layer 28a. An alignment region 28b that is disposed in a region that overlaps the region 18a in a plan view and that has a relatively strong alignment regulating force is disposed in a region that overlaps the alignment region 18b in a plan view.

According to the liquid crystal device 200 having the above-described configuration, since the plurality of alignment regions 18a and 18b are arranged in the island-like portions 9a and 9b that form a substantially radial liquid crystal region in the sub-pixel, The effect of improving the viewing angle characteristics can be obtained every time, and a liquid crystal device having more excellent viewing angle characteristics can be realized.
In the liquid crystal device 200 of the present embodiment, the formation method of the alignment films 18 and 28 can be the same as that of the first embodiment, and the material of the alignment films 18 and 28 is also Both organic and inorganic materials can be used.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIGS. FIG. 7 is a plan configuration diagram of a TFT array substrate in an arbitrary sub-pixel of the liquid crystal device 300 of the present embodiment, and corresponds to FIG. 2 in the previous first embodiment. FIG. 8 is a cross-sectional configuration diagram of the liquid crystal device 300 taken along the line GG ′ of FIG. 7 and corresponds to FIG. 3 in the first embodiment.

  The liquid crystal device 300 of the present embodiment is obtained by changing the electrode structure and the configuration of the alignment film with respect to the liquid crystal device 100 according to the first embodiment. Therefore, in the following, the structure of the electrode structure and the alignment film will be described in detail, and the description of other structures will be omitted as appropriate. 7 and 8, the same reference numerals are given to the same components as those in FIGS. 1 to 3.

  As shown in FIG. 7, a pixel electrode 9 made of a transparent conductive film having a rectangular shape in plan view and a TFT 30 electrically connected to the pixel electrode 9 are provided in one subpixel of the liquid crystal device 300. Further, the data line 6a extends along the longitudinal direction (X-axis direction) of the pixel electrode 9, and the scanning line 3a extends along the short-side direction (Y-axis direction). The TFT 30 is formed in the vicinity of the intersection of the data line 6a and the scanning line 3a, and is electrically connected to the data line 6a and the scanning line 3a.

  The pixel electrode 9 is formed with a plurality of slit-like openings 9c and 9d that form the alignment control means for the vertically aligned liquid crystal. Of these, two openings 9c extend to the right in the figure, and others The two openings 9d are formed to extend downward in the figure. In the sub-pixel, a plurality of dielectric protrusions 21a and 21b that form ridges extending in parallel with the opening 9c or the opening 9d are provided on the counter substrate 20 side. The two dielectric protrusions 21a extend in parallel with the opening 9c, and are disposed between the two adjacent openings 9c, 9c. On the other hand, the other two dielectric protrusions 21b extend in parallel with the opening 9d, and are disposed between the two adjacent openings 9d and 9d. The dielectric protrusion 21a and the dielectric protrusion 21b arranged at the center of the sub pixel in the X-axis direction are connected at the center of the sub pixel.

  In the cross-sectional structure shown in FIG. 8, the pixel electrode 9 having openings 9c and 9d is formed on the liquid crystal layer 50 side of the substrate body 10A, and the alignment film 18 is formed to cover the pixel electrode 9. ing. On the other hand, the color filter 22 and the counter electrode 21 are formed on the liquid crystal layer 50 side of the substrate body 20A, and dielectric protrusions 21a and 21b are formed on the counter electrode 21, and the dielectric protrusions 21a and 21b and An alignment film 28 is formed so as to cover the counter electrode 21.

  As shown in FIG. 7, the alignment film 18 covering the pixel electrode 9 has a plurality of alignment regions 18 a and 18 b having different alignment regulating forces with respect to the liquid crystal in the plane region of one subpixel. Similar to the previous embodiment, the alignment region 18a forms a region A having a relatively weak alignment regulating force, and the alignment region 18b forms a region B having a relatively strong alignment regulating force. . The alignment regions 18a and 18b have boundaries at positions along the dielectric protrusions 21a and 21b, which are alignment control means provided in the sub-pixels. The alignment region 18a is formed in an inverted V-shaped region in the center of the sub-pixel surrounded by the two dielectric protrusions 21a and 21a and the two dielectric protrusions 21b and 21b, and the periphery of the alignment region 18a. The alignment region 18b is formed in the triangular region.

  According to the liquid crystal device 300 having the above-described configuration, the alignment region is controlled according to the liquid crystal region controlled by a plurality of alignment control means (openings 9c and 9d and dielectric protrusions 21a and 21b) provided in the sub-pixel. Since 18a and 18b are arranged, the effect of improving the viewing angle characteristics can be obtained for each liquid crystal region, and a liquid crystal device having excellent viewing angle characteristics can be realized. As described above, the present invention can be applied regardless of the electrode structure of the liquid crystal device, and an excellent effect of improving the viewing angle characteristic can be obtained.

  Note that the arrangement of the alignment regions 18a and 18b in the liquid crystal device 300 of the present embodiment is merely an example, and it is needless to say that other arrangement forms may be adopted. For example, the alignment region 18a is disposed in a region sandwiched between the two openings 9c and 9c and a region surrounded by the two openings 9d and 9d, and the alignment region 18b is disposed in the planar region where the sub-pixel is left. May be. Alternatively, the alignment regions 18a and 18b may be arranged on the left and right half plane regions of the pixel electrode 9, respectively, and the alignment regions 18a and 18b are arranged so as to bisect the pixel electrode in the vertical direction of the drawing. Also good.

In addition, as a method for forming the alignment film 18, the same formation method as in the first embodiment can be used, and both the organic material and the inorganic material can be used as the material of the alignment film 18.
In addition, the alignment film 28 on the counter substrate 20 side can also be configured to be partitioned into a plurality of alignment regions. In this case, as in the previous embodiment, the alignment film 18 on the TFT array substrate 10 side. It is preferable that a plurality of alignment regions are arranged corresponding to the alignment regions 18a and 18b.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described with reference to FIGS. FIG. 9 is a plan view of a TFT array substrate in an arbitrary sub-pixel of the liquid crystal device 400 of the present embodiment, and is a drawing corresponding to FIG. 2 in the first embodiment. FIG. 10 is a cross-sectional configuration diagram of the liquid crystal device 300 taken along the line HH ′ of FIG. 7 and corresponds to FIG. 3 in the first embodiment.

  The liquid crystal device 400 of the present embodiment is a VAN mode transflective liquid crystal device in which a reflective layer is partially formed in one subpixel. In the following, a configuration different from the previous embodiment will be described in detail, and description of other configurations will be omitted as appropriate. 9 and 10, the same reference numerals are given to the same components as those in FIGS. 1 to 3.

The pixel electrode 9 provided in the sub-pixel shown in FIG. 9 is made of a transparent conductive film such as ITO, and is roughly divided into three island-shaped portions 91 to 93, and between the adjacent island-shaped portions 91 and 92, and the island-shaped Between the parts 92 and 93, it has the shape connected with those center parts. The reflective layer 93 </ b> R is arranged so as to overlap the island-like portion 93 arranged at the right end in the drawing among the three island-like portions 91 to 93. The reflective layer 93R is made of a light-reflective metal film such as Al (aluminum) or Ag (silver), for example, and the island-shaped portion 93 is formed so as to overlap the reflective layer 29 in a planar manner. The area forms a reflective display area of the sub-pixel. Actually, the surface of the reflective layer 93R is provided with a concavo-convex shape, and the reflected light is scattered by the concavo-convex, so that a display with good visibility can be obtained.
In addition, the region where the other island-shaped portions 91 and 92 are formed is the transmissive display region of the sub-pixel. Therefore, in the liquid crystal device 400 according to the present embodiment, the area region slightly less than 1/3 of the displayable region. Contributes to reflective display, and the remaining 2/3 area area contributes to transmissive display.

  In addition, since the pixel electrode of the part which connects the island-shaped parts 91-93 also consists of transparent conductive films, such as ITO, this connection part also contributes to a transmissive display. Dielectric protrusions 191 to 193 that are alignment regulating means for regulating the alignment of the liquid crystal are disposed at substantially the center of each of the island-shaped portions 91 to 93.

  Looking at the cross-sectional structure of the liquid crystal device shown in FIG. 10, insulating films 11 to 13 constituting the circuit layer on which the TFT 30 is formed are laminated on the liquid crystal layer 50 side of the substrate body 10 </ b> A constituting the TFT array substrate 10. The reflective layer 93R is formed on the uppermost second interlayer insulating film 13. A liquid crystal layer thickness adjusting layer 25 is formed corresponding to the formation region of the reflective layer 93R, and the pixel electrode 9 is formed across the liquid crystal layer thickness adjusting layer 25 and the second interlayer insulating film 13. . An alignment film 18 is formed so as to cover the pixel electrode 9.

The thickness of the liquid crystal layer 50 is made different between the reflective display region and the transmissive display region by the liquid crystal layer thickness adjusting layer 25 partially formed in the sub pixel, and a so-called multi-gap structure is realized for each sub pixel. It has become a thing. The liquid crystal layer thickness adjusting layer 25 is formed using an organic film such as an acrylic resin, and has a thickness of about 2 μm ± 1 μm, for example. The thickness of the liquid crystal layer 50 in the portion where the liquid crystal layer thickness adjusting layer 25 does not exist is about 2 μm to 6 μm, and the thickness of the liquid crystal layer 50 in the reflective display region is about half of the thickness of the liquid crystal layer 50 in the transmissive display region. is there. The liquid crystal device 400 according to the present embodiment can display a bright and high-contrast display with such a configuration.
Note that a tapered step portion in which the layer thickness of the liquid crystal layer thickness adjusting layer 25 continuously changes is formed in the vicinity of the boundary between the reflective display region and the transmissive display region. It partially overlaps with the linear electrode film (connecting portion) connecting the island-like portions 92 and 93.

  A color filter 22 and a counter electrode 21 are stacked on the substrate body 20 </ b> A constituting the counter substrate 20, and dielectric protrusions 191 to 193 are provided on the counter electrode 21. An alignment film 28 is formed so as to cover the dielectric protrusions 191 to 193 and the counter electrode 21.

  As shown in FIG. 9, the alignment film 18 covering the pixel electrode 9 has a plurality of alignment regions 18a and 18b having different alignment regulating forces for liquid crystals in the plane region of one subpixel. Similar to the previous embodiment, the alignment region 18a forms a region A having a relatively weak alignment regulating force, and the alignment region 18b forms a region B having a relatively strong alignment regulating force. . The alignment region 18a is formed in a region corresponding to one island-like portion 91 of the two island-like portions 91 and 92 constituting the transmissive display region, and the alignment region 18b is the other of the other islands constituting the transmissive display region. It is formed in a region corresponding to the island-shaped portion 92 and the island-shaped portion 93 constituting the reflective display region. That is, in this embodiment, a plurality of alignment regions 18a and 18b are arranged in the transmissive display region of the sub-pixel, and only a single alignment region 18b is arranged in the reflective display region.

According to the liquid crystal device 400 having the above-described configuration, since the plurality of alignment regions 18a and 18b are arranged in the sub-pixel (transmission display region), the viewing angle characteristics in the transmissive display are improved as in the previous embodiment. An effect can be obtained, and a liquid crystal device having excellent viewing angle characteristics can be realized.
In the present embodiment, the configuration in which the single alignment region 18b is arranged in the reflective display region has been described. Of course, a plurality of alignment regions may be arranged in the reflective display region, and such a configuration is adopted. By doing so, the viewing angle characteristic in the reflective display can be improved.

  Although the embodiments of the liquid crystal device according to the present invention have been described in detail above, the technical field of the present invention is not limited to the above-described embodiments. For example, in the above embodiment, the case where an amorphous silicon TFT is provided as a pixel switching element has been described. However, a structure in which a TFD (Thin Film Diode) is provided as a switching element may be used, and a structure in which a low-temperature polysilicon TFT is provided. It may be. In the first and second embodiments, the liquid crystal device including the pixel electrode 9 divided into two island-like portions 9a and 9b has been described. However, the pixel electrode divided into three or more island-like portions is used. It may be a configuration provided. In the fourth embodiment, a transflective liquid crystal device employing a multi-gap method has been described. However, a transflective liquid crystal device having a constant liquid crystal layer thickness in a sub-pixel may be used. In each embodiment, the dielectric protrusion provided as the orientation control means can be replaced with a slit-shaped opening provided in the electrode, and conversely, the slit-shaped opening can be replaced with a dielectric protrusion. Can do.

(Electronics)
FIG. 11 is a perspective view showing an example of an electronic apparatus according to the invention. A cellular phone 1300 shown in this figure includes the liquid crystal display device of the present invention as a small-sized display portion 1301 and includes a plurality of operation buttons 1302, an earpiece 1303, and a mouthpiece 1304. The display device of each of the above embodiments is not limited to the mobile phone, but is an electronic book, a personal computer, a digital still camera, a liquid crystal television, a viewfinder type or a monitor direct view type video tape recorder, a car navigation device, a pager, and an electronic notebook. , Calculators, word processors, workstations, videophones, POS terminals, devices equipped with touch panels, etc., and can be suitably used as image display means. In any electronic device, display of high brightness, high contrast, and wide viewing angle is possible. Is possible.

1 is a circuit configuration diagram of a liquid crystal device according to a first embodiment. The plane block diagram of the TFT array substrate in 1 sub pixel. FIG. 3 is a cross-sectional configuration diagram taken along line D-D ′ in FIG. 2. The graph which shows the difference in the electro-optical characteristic of the area | region where the orientation control force differs. FIG. 6 is a diagram showing one sub-pixel of a liquid crystal device according to a second embodiment. FIG. 6 is a cross-sectional configuration diagram taken along line F-F ′ in FIG. 5. FIG. 10 is a diagram showing one sub-pixel of a liquid crystal device according to a third embodiment. FIG. 8 is a cross-sectional configuration diagram taken along the line G-G ′ of FIG. 7. FIG. 10 is a diagram showing one sub-pixel of a liquid crystal device according to a fourth embodiment. FIG. 10 is a cross-sectional configuration diagram taken along line H-H ′ of FIG. 9. FIG. 11 is a perspective configuration diagram illustrating an example of an electronic device.

Explanation of symbols

  100, 200, 300, 400 Liquid crystal device, 9 pixel electrodes, 9a, 9b, 91-93 islands, 9c, 9d openings, 18, 28 alignment films, 18a, 18b, 28a, 28b alignment regions, 10 TFT arrays Substrate (first substrate), 20 Counter substrate (second substrate), 21a, 21b, 191 to 193 Dielectric protrusion, 30 TFT (switching element), 50 liquid crystal layer, 51 liquid crystal molecule

Claims (14)

An alignment film that sandwiches a liquid crystal layer made of liquid crystal having negative dielectric anisotropy between a pair of substrates arranged opposite to each other, and regulates the liquid crystal in the vertical direction on the liquid crystal layer side of each substrate Are provided,
At least one of the alignment films has a plurality of alignment regions having different alignment regulating forces with respect to the liquid crystal in one pixel region serving as an image display unit.   The liquid crystal device according to claim 1, wherein each of the alignment films facing each other with the liquid crystal layer interposed therebetween has the plurality of alignment regions.   The liquid crystal device according to claim 2, wherein the alignment regions facing each other with the liquid crystal layer interposed therebetween have the same alignment regulating force.   4. The liquid crystal device according to claim 1, wherein the alignment film is formed using a different alignment film material for each alignment region. 5.   The alignment film has a first alignment film formed on the substrate and a second alignment film partially formed on the first alignment film. The liquid crystal device according to any one of 1 to 3. A pair of electrodes facing each other with the liquid crystal layer sandwiched between each substrate is provided, and at least one of the pair of electrodes forms a plurality of liquid crystal regions in the one pixel region when a selection voltage is applied. Means are provided,
The liquid crystal device according to claim 1, wherein the alignment region is arranged corresponding to one or a plurality of the liquid crystal regions. A pixel electrode having a plurality of island-shaped portions and a connecting portion that electrically connects the island-shaped portions is provided on the substrate,
6. The liquid crystal device according to claim 1, wherein each of the plurality of alignment regions is disposed corresponding to a planar region of the island-shaped portion. A pixel electrode having a plurality of island-shaped portions and a connecting portion that electrically connects the island-shaped portions is provided on the substrate,
6. The liquid crystal device according to claim 1, wherein a plurality of the alignment regions are arranged in a planar region of the island-shaped portion. A transmissive display area and a reflective display area are partitioned in the one pixel area,
The liquid crystal device according to claim 1, wherein a plurality of the alignment regions having different alignment regulating forces are arranged in the transmissive display region or the reflective display region.   The liquid crystal device according to claim 9, wherein a plurality of the alignment regions having different alignment regulating forces are arranged in the transmissive display region. A manufacturing method of a liquid crystal device according to claim 1,
In the liquid crystal device, the alignment film formed on the substrate is selectively irradiated with light through a mask so as to partition and form a plurality of alignment regions having different alignment regulating forces on the liquid crystal. Production method. A method of manufacturing a liquid crystal device according to claim 4,
A liquid crystal device comprising: a plurality of alignment regions having different alignment regulating forces, wherein a different type of alignment film material is selectively disposed on the substrate by using a droplet discharge method. Production method. A manufacturing method of a liquid crystal device according to claim 5,
Forming a first alignment film on the substrate;
Applying a photosensitive alignment film material on the first alignment film to form a coating film;
And a step of forming a second alignment film by partially removing the coating film by exposure and development treatment, and producing a liquid crystal device.   An electronic apparatus comprising the liquid crystal device according to claim 1.

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