JP2009237228A - Liquid crystal display device and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device which hardly brings about display unevenness and can obtain a uniform image quality throughout an image display region even when local unevenness in electrode shape is caused. <P>SOLUTION: The liquid crystal display device is an FFS type liquid crystal display device having a pixel electrode 9 and a common electrode 19 laminated on one substrate with an insulating film therebetween. The pixel electrode 9 includes a plurality of band-shaped electrodes 9c and has an electrode pattern formed such that at least one of a ratio L/S, M, and θ is irregularly formed, wherein: L is the width of the band-shaped electrodes 9c; S is the width of slits Sc disposed between adjacent band-shaped electrodes; M is the length of the slits Sc; and θ is an angle formed between the band-shaped electrodes 9c and an X axis. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device and an electronic apparatus.

As one form of a liquid crystal display device, a method of controlling the alignment of liquid crystal molecules by applying an electric field in the substrate surface direction to a liquid crystal layer (hereinafter referred to as a lateral electric field method) is known. As the lateral electric field method, an IPS (In-Plane Switching) method and an FFS (Fringe-Field Switching) method are known. In a horizontal electric field type liquid crystal display device, a plurality of strip electrodes are formed in one sub-pixel region, and the alignment state of liquid crystal molecules is controlled by an electric field in the horizontal direction of the substrate formed at the periphery of the strip electrodes. The shape of the strip electrode is formed uniformly in the image display area. For example, when the width of the strip electrode is L and the width of the slit disposed between the adjacent strip electrodes is S, the ratio L / S is designed to be equal for all the strip electrodes. By doing so, uniform display characteristics are realized in the entire image display area.
JP 2003-233083 A

  However, the slit width S and ratio L / S may not be uniformly formed in the entire image display region due to manufacturing errors. That is, the strip electrode is formed by forming a strip-shaped resist pattern on the surface of the electrode material and etching the electrode material using the resist pattern as a mask. The resist pattern is formed by performing exposure processing and development processing using an exposure mask. However, the resist pattern may vary in shape due to deflection of the exposure mask or diffraction of light transmitted through the exposure mask. is there. For example, when the width of a resist pattern is S and the width of a slit arranged between adjacent resist patterns is L, regions having different ratios L / S have a one-dimensional or two-dimensional spread. May be formed. Since such a region has a voltage-transmittance characteristic different from that of other regions, it is likely to be visually recognized as shading unevenness, causing a reduction in image quality.

  The present invention has been made in view of such circumstances, and even when local variations occur in the electrode shape when the pixel electrode is formed, display unevenness is unlikely to occur, and the entire image display region is generated. An object of the present invention is to provide a liquid crystal display device and an electronic apparatus that can obtain uniform image quality.

In order to solve the above problems, a liquid crystal display device according to the present invention includes a pair of opposing substrates, a liquid crystal layer sandwiched between the pair of substrates, and the liquid crystal layer of one of the pair of substrates. A plurality of second electrodes disposed on the first electrode on the liquid crystal layer side of the one substrate, with a plurality of second electrodes opposed to each other with an insulating film interposed therebetween. Is a liquid crystal display device that is two-dimensionally arranged on the one substrate along a first arrangement axis and a second arrangement axis that are orthogonal to each other, wherein the second electrode has a plurality of strip electrodes. Provided, the width of the strip electrode is L, the width of the slit disposed between adjacent strip electrodes is S, the length of the slit is M, and the angle formed by the strip electrode and the first array axis is The second electrode has a ratio L / S, a length M, and an angle θ. At least one is provided with an irregularly formed electrode pattern.
According to this configuration, even if the shape of the second electrode slightly deviates from the target shape due to a manufacturing error, at least one of the ratio L / S, the length M, and the angle θ originally varies irregularly. Therefore, deviation due to manufacturing errors is not noticeable. Therefore, uniform image quality can be obtained as a whole. Further, even if the second electrode can be formed without manufacturing error, uniform image quality can be obtained as a whole with this configuration.

In the present invention, for each of the second electrodes, one type of electrode pattern is selected from a plurality of types of electrode patterns in which at least one of the ratio L / S, the length M, and the angle θ is irregularly formed. The types of electrode patterns selected between the second electrodes adjacent to each other along the first array axis and between the second electrodes adjacent to each other along the second array axis are irregular. It is desirable to be.
According to this configuration, since it is not necessary to set different electrode patterns for all the second electrodes, the design of the second electrodes is facilitated.

In the present invention, for each of the second electrodes, one type of electrode pattern is selected from a plurality of types of electrode patterns in which at least one of the ratio L / S, the length M, and the angle θ is irregularly formed. When a region composed of a plurality of second electrodes selected and adjacent to each other is defined as a unit region, the types of electrode patterns of the plurality of second electrodes arranged in one unit region are equal to each other, and It is desirable that the types of electrode patterns to be selected are irregular between unit regions adjacent along the first array axis and between unit regions adjacent along the second array axis.
According to this configuration, since it is not necessary to set different electrode patterns for all the second electrodes, the design of the second electrodes is facilitated.

The liquid crystal display device of the present invention includes a pair of opposing substrates, a liquid crystal layer sandwiched between the pair of substrates, and a first electrode provided on the liquid crystal layer side of one of the pair of substrates. And a plurality of second electrodes opposed to each other with an insulating film on the first electrode on the liquid crystal layer side of the one substrate, wherein the plurality of second electrodes are orthogonal to each other. A liquid crystal display device two-dimensionally arranged on the one substrate along an axis and a second array axis, wherein the second electrode is provided with a plurality of band electrodes, and the width of the band electrode Where L is the width of the slit disposed between adjacent strip electrodes, M is the length of the slit, and θ is the angle between the strip electrode and the first array axis. For each of the two electrodes, a compound having at least one of a ratio L / S, a length M, and an angle θ is different. One type of electrode pattern is selected from among several types of electrode patterns, and the second electrodes adjacent to each other along the first array axis and the second electrodes adjacent to each other along the second array axis. Thus, the type of the electrode pattern selected is irregular.
According to this configuration, even if the shape of the second electrode slightly deviates from the target shape due to manufacturing errors, at least one of the ratio L / S, the length M, and the angle θ originally varies irregularly. Therefore, deviation due to manufacturing errors is not noticeable. Therefore, uniform image quality can be obtained as a whole. In addition, since it is not necessary to set different electrode patterns for all the second electrodes, the design of the second electrodes is facilitated.

The liquid crystal display device of the present invention includes a pair of opposing substrates, a liquid crystal layer sandwiched between the pair of substrates, and a first electrode provided on the liquid crystal layer side of one of the pair of substrates. And a plurality of second electrodes opposed to each other with an insulating film on the first electrode on the liquid crystal layer side of the one substrate, wherein the plurality of second electrodes are orthogonal to each other. A liquid crystal display device two-dimensionally arranged on the one substrate along an axis and a second array axis, wherein the second electrode is provided with a plurality of band electrodes, and the width of the band electrode Is L, S is the width of the slit disposed between adjacent strip electrodes, M is the slit length, and θ is the angle between the strip electrode and the first array axis. For each of the two electrodes, a compound having at least one of a ratio L / S, a length M, and an angle θ is different. When one type of electrode pattern is selected from among several types of electrode patterns and a region constituted by a plurality of second electrodes adjacent to each other is defined as a unit region, a plurality of second patterns arranged in one unit region The types of electrode patterns of the electrodes are equal to each other, and are selected between unit regions adjacent to each other along the first array axis and between unit regions adjacent to each other along the second array axis The pattern type is irregular.
According to this configuration, even if the shape of the second electrode slightly deviates from the target shape due to manufacturing errors, at least one of the ratio L / S, the length M, and the angle θ originally varies irregularly. Therefore, deviation due to manufacturing errors is not noticeable. Therefore, uniform image quality can be obtained as a whole. In addition, since it is not necessary to set different electrode patterns for all the second electrodes, the design of the second electrodes is facilitated.

The liquid crystal display device of the present invention includes a pair of opposing substrates, a liquid crystal layer sandwiched between the pair of substrates, and a first electrode provided on the liquid crystal layer side of one of the pair of substrates. And a plurality of second electrodes opposed to each other with an insulating film on the first electrode on the liquid crystal layer side of the one substrate, wherein the plurality of second electrodes are orthogonal to each other. A liquid crystal display device two-dimensionally arranged on the one substrate along an axis and a second array axis, wherein the second electrode is provided with a plurality of band electrodes, and the width of the band electrode Where L is the width of the slit disposed between adjacent strip electrodes, M is the length of the slit, and θ is the angle between the strip electrode and the first array axis. Between adjacent strip electrodes along one array axis, and adjacent along the second array axis Between each other strip electrodes, the ratio L / S, at least one of the length M, and the angle θ, characterized in that it is irregularly formed.
According to this configuration, even if the shape of the second electrode slightly deviates from the target shape due to a manufacturing error, at least one of the ratio L / S, the length M, and the angle θ originally varies irregularly. Therefore, deviation due to manufacturing errors is not noticeable. Therefore, uniform image quality can be obtained as a whole.

  In the present invention, it is desirable that the size of the unit region is a size that cannot be visually recognized by the naked eye. “Unrecognizable with the naked eye” means that the viewer cannot see or pay attention when he / she looks directly at the entire screen in the normal usage mode, and enlarges and observes a part of the image display area using a microscope or the like. It doesn't mean that you can't see it. The size that cannot be visually recognized by the naked eye is assumed to be a size of several hundred μm or less, more preferably a size of 100 μm or less. This is because although it depends on individual differences, it is considered that the size of several hundred μm or less cannot be clearly seen with the naked eye. If the size of the unit region is too small, the number of unit regions increases, and the design of the strip electrode becomes complicated. Therefore, it is desirable to limit the number of second electrodes included in the unit region to a certain number or less (for example, 10 or less).

In the present invention, it is desirable that there are three or more types of electrode patterns.
If there are two types of electrode patterns, there is an effect of preventing display unevenness, but by using three or more types, it is possible to reliably prevent display unevenness.

An electronic apparatus according to the present invention includes the above-described liquid crystal display device according to the present invention.
According to this configuration, it is possible to provide an electronic device that can display a high-quality image.

[First Embodiment]
Hereinafter, a liquid crystal display device according to a first embodiment of the present invention will be described with reference to the drawings. In the following description, the arrangement of members will be described using an XYZ orthogonal coordinate system. In this embodiment, the X-axis direction is the scanning line extending direction, the Y-axis direction is the data line extending direction, and the Z-axis direction is the viewing direction of the image display area by the observer. In each drawing, in order to make each layer and each member large enough to be recognized on the drawing, the scale is changed for each layer and each member.

  The liquid crystal display device of the present embodiment employs a method called an FFS (Fringe Field Switching) method among methods for displaying an image by applying an electric field substantially in the substrate surface direction to the liquid crystal to control alignment. It is a display device. The liquid crystal display device according to the present embodiment is a color liquid crystal display device having a color filter layer on a substrate, and outputs three sub-color lights for R (red), G (green), and B (blue). One pixel constitutes one pixel. In the following description, an area serving as a minimum unit for image display is referred to as a “sub-pixel area”, and an area constituted by a set of (R, G, B) sub-pixels is referred to as a “pixel area”. In addition, an area formed by a plurality of pixels arranged two-dimensionally in the X-axis direction and the axial direction is referred to as an “image display area”.

  FIG. 1 is an equivalent circuit diagram of the liquid crystal display device 100 of the present embodiment. In a plurality of sub-pixel areas formed in a matrix that constitutes an image display area of the liquid crystal display device 100, a pixel electrode 9 and a TFT 30 for switching control of the pixel electrode 9 are formed. A liquid crystal layer 50 is interposed between the pixel electrode 9 and the common electrode 19. The common electrode 19 is electrically connected to a common line 3b extending from the scanning line driving circuit 102, and is held at a common potential in a plurality of subpixels.

  A data line 6 a extending from the data line driving circuit 101 is electrically connected to the source of the TFT 30. The data line driving circuit 101 supplies the image signals S1, S2,..., Sn to each sub-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 3 a extending from the scanning line driving circuit 102 is electrically connected to the gate of the TFT 30. Scan signals G1, G2,..., Gm, which are supplied from the scanning line driving circuit 102 to the scanning lines 3a at predetermined timing, are applied to the gates of the TFTs 30 in this order in a line-sequential manner.

  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 through the pixel electrode 9 are held for a certain period between the pixel electrode 9 and the common electrode 19 facing through the liquid crystal.

  FIG. 2 is a plan view of an arbitrary sub-pixel region of the liquid crystal display device 100. In the sub-pixel region of the liquid crystal display device 100, a pixel electrode (second electrode) 9 that is long in the Y-axis direction, which has a substantially ladder shape in plan view, and a substantially rectangular shape in a plane that is disposed so as to overlap the pixel electrode 9 in a planar manner. Common electrode (first electrode) 19 is provided. The pixel electrode 9 includes a plurality of (in the figure, 15) strip-shaped electrodes 9c extending substantially in the X-axis direction, and a frame body portion 9a having a substantially rectangular frame shape in plan view connected to both ends of the strip-shaped electrodes 9c. I have.

  The pixel electrode 9 is provided with a plurality of slits Sc (slit-like openings) extending substantially parallel to the X axis. At both ends of the slit Sc on the frame body portion 9a side, curved portions Se and Sf that are curved in a direction away from an axis parallel to the X axis through the center of the slit Sc are formed. A portion of the slit Sc other than the curved portions Se and Sf is a straight portion Sd formed in a straight line. The straight line portion Sd is disposed slightly inclined with respect to the X axis. In the present embodiment, the straight line portion Sd extends in a direction that intersects the X axis clockwise by an acute angle θ. The curved portion Se is provided at the end of the straight line portion Sd opposite to the data line 6a, and compared with the center line (a line parallel to the Y axis) at the center of the slit Sc (straight line portion Sd). As the distance from the data line 6a increases, the curve is closer to the scanning line 3a. The curved portion Sf is provided at the end of the straight line portion Sd on the data line 6a side, and the data line 6a is compared with the center line (line parallel to the Y axis) at the center of the slit Sc (straight line portion Sd). Is curved so as to move away from the scanning line 3a as it approaches.

  The pixel electrode 9 is formed with a plurality of strip electrodes 9c arranged in the Y-axis direction in parallel with each other by a plurality of slits Sc. At both ends of the strip electrode 9c connected to the frame body portion 9a, curved portions 9e and 9f are formed which are curved in a direction away from an axis parallel to the X axis through the center of the strip electrode 9c. A portion of the strip electrode 9c other than the curved portions 9e and 9f is a straight portion 9d formed in a straight line. The straight line portion 9d is disposed slightly inclined with respect to the X axis. In the case of the present embodiment, the extending direction of the linear portion 9d is a direction that intersects the acute angle by an angle θ in the clockwise direction with respect to the X axis. The curved portion 9e is provided at the end of the linear portion 9d opposite to the data line 6a, and is compared with the central line (line parallel to the Y axis) at the center of the strip electrode 9c (linear portion 9d). As the distance from the data line 6a increases, the curve becomes closer to the scanning line 3a. The curved portion 9f is provided at the end of the straight line portion 9d on the data line 6a side, and is a data line compared to the center line (line parallel to the Y axis) at the center of the strip electrode 9c (straight line portion 9d). As it approaches 6a, it is curved so as to move away from the scanning line 3a.

  In FIG. 2, the curved portions 9e and 9f are formed in a smooth curved shape, but the curved portions 9e and 9f may be formed by a plurality of straight portions, or a curved portion and a straight portion. In this case, it is desirable that the straight line part and the curved line part include an inclined part that generates an electric field that gives the liquid crystal molecules rotation in the same direction as the direction in which the liquid crystal molecules rotate. In the case of the liquid crystal display device of FIG. 2, portions other than the end portions (connecting portions with the frame body portion 9a) of the curved portions 9e and 9f are the inclined portions.

  In the present embodiment, the width S of the straight portion Sd of the slit Sc (the width in the direction perpendicular to the straight portion Sd) is equal in all the slits Sc. The length of the straight line portion Sd (the length in the direction parallel to the extending direction of the straight line portion Sd) is equal in all the slits S except for the slits S formed at both ends of the pixel electrode 9 in the Y-axis direction. ing. Further, the angle θ formed by the straight line portion Sd and the X axis is formed equally in all the slits S.

  On the other hand, the intervals (S 1, S 2) in the Y-axis direction between the straight portions Sd are irregularly formed in the pixel electrode 9. Thereby, the width (L1, L2) in the Y-axis direction of the linear portion 9d of the strip electrode 9c is irregularly formed in the pixel electrode 9. When the width of the straight line portion 9d in the direction perpendicular to the straight line portion 9d is L, and the width of the straight line portion Sd in the direction perpendicular to the straight line portion Sd is S, a plurality of pixels arranged in one subpixel region are arranged. The ratio L / S is irregularly formed between the strip electrodes.

  Although only one pixel electrode 9 is shown in FIG. 2, the shape of the pixel electrode 9 is common to each sub-pixel region. That is, the pixel electrode 9 includes an electrode pattern in which the ratio L / S is irregularly formed in one sub-pixel region, but a plurality of pixels arranged in a matrix in the X-axis direction and the Y-axis direction. Between the sub-pixel areas, all the electrode patterns of the pixel electrodes 9 are formed equally.

  In the sub-pixel area, data lines 6a extending in the Y-axis direction and scanning lines 3a extending in the X-axis direction are formed. A TFT 30 is provided in the vicinity of the intersection of the data line 6a and the scanning line 3a. The TFT 30 includes a semiconductor layer 35 made of amorphous silicon formed so as to partially overlap the scanning line 3 a, and a source electrode 6 b and a drain electrode 32 formed so as to partially overlap the semiconductor layer 35. . The scanning line 3 a functions as a gate electrode of the TFT 30 at a position overlapping the semiconductor layer 35 in plan view. The source electrode 6 b is branched from the data line 6 a and extends to the semiconductor layer 35. A pixel electrode 9 is disposed on the drain electrode 32, and a pixel contact hole 45 is provided at a position where the two overlap in a planar manner. The drain electrode 32 and the pixel electrode 9 are electrically connected via the pixel contact hole 45.

  3 is a cross-sectional view taken along the line AA ′ of FIG. The liquid crystal display device 100 includes a TFT array substrate 10, a counter substrate 20 disposed opposite to the TFT array substrate 10, a liquid crystal layer 50 sandwiched between the TFT array substrate 10 and the counter substrate 20, and the TFT array substrate 10. The first polarizing plate 14 provided on the outer surface side (the side opposite to the liquid crystal layer 50), the second polarizing plate 24 provided on the outer surface side of the counter substrate 20, and the outer surface side of the first polarizing plate 14. The lighting device 90 is provided. And it is the structure by which illumination light is irradiated from the outer surface side of the 1st polarizing plate 14 with the illuminating device 90 provided with the light-guide plate 91 and the reflecting plate 92. FIG.

  The TFT array substrate 10 has a translucent substrate body 10A made of glass, quartz, plastic or the like as a base, and a scanning line 3a is formed on the inner surface side (liquid crystal layer 50 side) of the substrate body 10A. A gate insulating film 11 made of a transparent insulating film such as silicon oxide is formed so as to cover the line 3a.

  An amorphous silicon semiconductor layer 35 is formed on the gate insulating film 11, and a source electrode 6 b and a drain electrode 32 are provided so as to partially run over the semiconductor layer 35. The semiconductor layer 35 is opposed to the scanning line 3 a via the gate insulating film 11, and the scanning line 3 a constitutes the gate electrode of the TFT 30 in the opposed region.

  A first interlayer insulating film 12 made of silicon oxide or the like is formed so as to cover the semiconductor layer 35, the source electrode 6 b, and the drain electrode 32. A flat solid common electrode 19 made of a transparent conductive material such as ITO is formed on the first interlayer insulating film 12. A second interlayer insulating film 13 made of silicon oxide or the like is formed so as to cover the common electrode 19, and a pixel electrode 9 made of a transparent conductive material such as ITO is patterned on the second interlayer insulating film 13.

  A pixel contact hole 45 that reaches the drain electrode 32 through the first interlayer insulating film 12 and the second interlayer insulating film 13 is formed. A part of the pixel electrode 9 is buried in the pixel contact hole 45, and the pixel electrode 9 and the drain electrode 32 are electrically connected. Corresponding to the region where the pixel contact hole 45 is formed, the common electrode 19 is also provided with an opening so that the common electrode 19 and the pixel electrode 9 do not come into contact with each other.

  A first alignment film 18 made of polyimide or the like is formed in a region on the second interlayer insulating film 13 covering the pixel electrode 9. The first alignment film 18 is subjected to an alignment process such as a rubbing process to align the liquid crystal in a predetermined direction. In the present embodiment, the alignment regulating direction by the first alignment film 18 is parallel to the extending direction of the scanning line 3a and intersects the extending direction of the slit S of the pixel electrode 9.

  The counter substrate 20 has a translucent substrate body 20A such as glass, quartz, or plastic as a base, and a color filter layer 22 is provided on the inner surface side (liquid crystal layer 50 side) of the substrate body 20A. The color filter layer 22 is disposed corresponding to the sub-pixel region, and is made of, for example, acrylic and contains a color material corresponding to the display color of each sub-pixel.

  A second alignment film 28 made of polyimide or the like is formed on the inner surface side of the color filter layer 22. The second alignment film 28 has the same configuration as the first alignment film 18 on the TFT array substrate 10 side, and the alignment regulating direction by the second alignment film 28 is antiparallel to the alignment regulating direction of the first alignment film 18. Therefore, the liquid crystal layer 50 exhibits an initial alignment state of horizontal alignment between the TFT array substrate 10 and the counter substrate 20.

FIG. 4 is an explanatory diagram of an arrangement relationship of optical axes such as optical elements constituting the liquid crystal display device 100. The transmission axis 155 of the first polarizing plate 14 is parallel to the Y axis. The transmission axis 153 of the second polarizing plate 24 is parallel to the X axis. The alignment films 18 and 28 are rubbed in the same direction in plan view, and the direction is a rubbing direction 151. The rubbing direction (orientation regulating direction) 151 is parallel to the X-axis direction. A direction 158 of a horizontal electric field generated between the pixel electrode 9 and the common electrode 19 is a direction orthogonal to the extending direction of the strip electrode 9c formed on the pixel electrode. The strip electrode 9c extends from the X axis in a direction intersecting clockwise by 5 ° to 15 °. Therefore, the direction 158 of the transverse electric field generated between the common electrode 19 and the pixel electrode 9 is a direction forming an 5 ° to 15 ° in the clockwise direction (as shown in Figure 4, reference numeral theta _E) from the Y-axis .

  In the liquid crystal display device 100 configured as described above, an image signal (voltage) is supplied to the pixel electrode 9 through the TFT 30, thereby generating an electric field in the substrate surface direction between the pixel electrode 9 and the common electrode 19. To drive the liquid crystal. Then, display is performed by changing the transmittance for each sub-pixel region. That is, in a state where no voltage is applied to the pixel electrode 9, the liquid crystal molecules constituting the liquid crystal layer 50 are horizontally aligned parallel to the rubbing direction. When an electric field in a direction perpendicular to the extending direction of the strip electrode 9c constituting the pixel electrode 9 is generated in the liquid crystal layer 50 via the pixel electrode 9 and the common electrode 19, the liquid crystal molecules rotate within the substrate plane. And oriented in a direction parallel to the direction of the electric field.

  The illumination light emitted from the illumination device 90 is transmitted through the first polarizing plate 14, thereby being converted into linearly polarized light along the transmission axis of the first polarizing plate 14, and is incident on the liquid crystal layer 50. If the liquid crystal layer 50 is in an off state (non-selected state), the linearly polarized light incident on the liquid crystal layer 50 is emitted from the liquid crystal layer 50 in the same polarization state as that at the time of incidence. This linearly polarized light is absorbed by the second polarizing plate 24 having a transmission axis orthogonal to the linearly polarized light, and the sub-pixel region is darkly displayed. On the other hand, if the liquid crystal layer 50 is in the on state (selected state), the linearly polarized light incident on the liquid crystal layer 50 is given a predetermined phase difference (1/2 wavelength) by the liquid crystal layer 50, and the polarization direction at the time of incidence. Is converted into linearly polarized light rotated by 90 ° from the liquid crystal layer 50 and emitted from the liquid crystal layer 50. Since this linearly polarized light is parallel to the transmission axis of the second polarizing plate 24, the linearly polarized light passes through the polarizing plate 24 and is visually recognized as display light, and the sub-pixel region is brightly displayed. Thus, a normally black mode liquid crystal display device is realized.

  Here, as shown in FIG. 2, an electrode pattern in which the ratio L / S between the width L of the strip electrode 9c and the width S of the slit Sc is irregularly formed in the Y-axis direction is formed in one pixel electrode. Is formed. Therefore, in the process of forming the pixel electrode 9, even if the shape of the pixel electrode is slightly deviated from the target shape due to a manufacturing error, the size of the ratio L / S originally varies irregularly. Misalignment due to is not noticeable. Therefore, uniform image quality can be obtained as a whole.

  In the present embodiment, the electrode pattern of the pixel electrode 9 is formed equally for all the pixel electrodes. However, the electrode pattern of the pixel electrode 9 is different for each pixel electrode 9 or for each unit region composed of a plurality of pixel electrodes 9. May be allowed.

FIG. 5A is a schematic plan view of an image display region when the electrode pattern of the pixel electrode 9 is irregularly formed in the X-axis direction and the Y-axis direction. In FIG. 5A, three types of electrode patterns having an irregularly formed ratio L / S are prepared (electrode pattern A ₁ , electrode pattern A ₂ , electrode pattern A ₃ ), and three types are provided for each pixel electrode 9. One type of electrode pattern is selected from among the electrode patterns A ₁ , A ₂ , and A ₃ . Between the pixel electrodes 9 adjacent along the X axis and between the pixel electrodes 9 adjacent along the Y axis, the types of electrode patterns selected are irregular.

  In FIG. 5A, three types of electrode patterns are used, but the number of types of electrode patterns is not limited to three, and may be two types or four or more types.

FIG. 5B is a schematic plan view of an image display region when a region constituted by a plurality of pixel electrodes 9 adjacent to each other is a unit region and the electrode pattern of the pixel electrode 9 is irregularly formed for each unit region. FIG. In FIG. 5B, three types of electrode patterns having an irregular L / S ratio are prepared (electrode pattern A ₁ , electrode pattern A ₂ , electrode pattern A ₃ ), and 3 adjacent to each other along the X axis. One type of electrode pattern is selected from the three types of electrode patterns A ₁ , A ₂ , and A ₃ for each unit region (in this case, for each pixel region) constituted by one pixel electrode 9. The types of electrode patterns of the plurality of pixel electrodes 9 arranged in one unit region are equal to each other, but between unit regions adjacent to each other along the X axis and between unit regions adjacent to each other along the Y axis Then, the types of electrode patterns to be selected are irregular.

  In FIG. 5B, three types of electrode patterns are used. However, the number of types of electrode patterns is not limited to three, and may be two types or four or more types.

  Further, the unit region is not limited to a region constituted by three pixel electrodes 9 adjacent along the X axis, but a region constituted by two or four or more pixel electrodes 9 adjacent along the X axis, Or it is good also as an area | region comprised by the 2 or more pixel electrode 9 adjacent along a Y-axis. Further, a region (a region composed of a plurality of pixel electrodes 9 corresponding to m columns × n rows) constituted by pixel electrodes corresponding to m columns adjacent along the X axis and pixel electrodes corresponding to n rows adjacent along the Y axis. ) As a unit region, the electrode pattern of the selected pixel electrode 9 may be irregularly formed for each unit region.

  In this case, it is desirable that the size of the unit region is a size that cannot be visually recognized with the naked eye. “Unrecognizable with the naked eye” means that the viewer cannot see or pay attention when he / she looks directly at the entire screen in the normal usage mode, and enlarges and observes a part of the image display area using a microscope or the like. It doesn't mean that you can't see it. The size that cannot be visually recognized by the naked eye is assumed to be a size of several hundred μm or less, more preferably a size of 100 μm or less. This is because although it depends on individual differences, it is considered that the size of several hundred μm or less cannot be clearly seen with the naked eye. If the size of the unit region is too small, the number of unit regions increases, and the design of the strip electrode becomes complicated. Therefore, it is desirable to limit the number of pixel electrodes 9 included in the unit region to a certain number or less (for example, 10 or less).

  FIG. 5C is a schematic plan view of the image display region when the electrode patterns of the pixel electrodes 9 are made different for all the pixel electrodes 9. In FIG. 5C, electrode patterns having irregular L / S ratios are prepared for the number of sub-pixel regions. In this case, the ratio L / S is irregularly formed between the strip electrodes adjacent along the X axis and between the strip electrodes adjacent along the Y axis.

[Second Embodiment]
FIG. 6 is a plan configuration diagram in an arbitrary one sub-pixel region of the liquid crystal display device 200 according to the second embodiment of the present invention. In the present embodiment, the same components as those in the liquid crystal display device according to the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

In the present embodiment, the width S of the straight portion Sd of the slit Sc (the width in the direction perpendicular to the straight portion Sd) is equal in all the slits Sc. However, the intervals in the Y-axis direction between the straight portions Sd are irregularly formed in the pixel electrode 9. Further, the length of the straight portion Sd (the length in the direction parallel to the extending direction of the straight portion Sd, or the length in the X-axis direction (W1, W2)), and the angle formed by the straight portion Sd and the X-axis ( θ ₁ and θ ₂ ) are also irregularly formed in the pixel electrode 9. Therefore, when the length of the straight line portion Sd is M and the angle between the straight line portion Sd and the X axis is θ, an electrode pattern in which the length M and the angle θ are irregularly formed in one pixel electrode is Is formed.

  Although only one pixel electrode 9 is shown in FIG. 6, the shape of the pixel electrode 9 is common to each sub-pixel region. That is, the pixel electrode 9 includes an electrode pattern in which the length M and the angle θ are irregularly formed in one sub-pixel region, but is arranged in a matrix in the X-axis direction and the Y-axis direction. All the electrode patterns of the pixel electrodes 9 are formed equally between the plurality of sub-pixel regions.

  According to the liquid crystal display device 200 of the present embodiment, in the process of forming the pixel electrode 9, even if the shape of the pixel electrode slightly deviates from the target shape due to a manufacturing error, the length M and the angle θ are not originally set. Since the rules vary, deviation due to manufacturing errors is not noticeable. Therefore, uniform image quality can be obtained as a whole.

  In the present embodiment, all of the length M and the angle θ are irregularly formed in one pixel electrode. However, it is sufficient that at least one of the length M and the angle θ is irregularly formed, Thereby, the same effect as this embodiment is acquired.

  Further, in this embodiment, the electrode pattern of the pixel electrode 9 is formed equally for all the pixel electrodes. However, the electrode pattern of the pixel electrode 9 is different for each pixel electrode 9 or for each unit region composed of a plurality of pixel electrodes 9. May be allowed.

For example, as shown in FIG. 5A, a plurality of types of electrode patterns in which at least one of the length M and the angle θ is irregularly formed are prepared (the electrode pattern A _{1 in} FIG. 5A). , Electrode pattern A ₂ , electrode pattern A ₃ ), and pixel electrode 9, one type of electrode pattern may be selected from a plurality of types of electrode patterns A ₁ , A ₂ , A ₃ . In this case, the types of electrode patterns to be selected are irregular between the pixel electrodes 9 adjacent along the X axis and between the pixel electrodes 9 adjacent along the Y axis.

As shown in FIG. 5B, a plurality of types of electrode patterns in which at least one of the length M and the angle θ is irregularly formed are prepared (in FIG. 5B, the electrode pattern A ₁ , Electrode pattern A ₂ , electrode pattern A ₃ ), and one type of electrode among the plurality of types of electrode patterns A ₁ , A ₂ , A ₃ for each unit region constituted by a plurality of pixel electrodes 9 adjacent to each other. A pattern may be selected. The types of electrode patterns of the plurality of pixel electrodes 9 arranged in one unit region are equal to each other, but between unit regions adjacent to each other along the X axis and between unit regions adjacent to each other along the Y axis Then, the types of electrode patterns to be selected are irregular.

  Further, as shown in FIG. 5C, electrode patterns in which at least one of the length M and the angle θ is irregularly formed are prepared in the number corresponding to the number of sub-pixel regions, and electrodes of all the pixel electrodes are prepared. The pattern may be different. In this case, at least one of the length M and the angle θ is irregularly formed between the strip electrodes adjacent along the X axis and between the strip electrodes adjacent along the Y axis. It will be.

[Third Embodiment]
FIG. 7 is a plan configuration diagram in an arbitrary one sub-pixel region of the liquid crystal display device 300 according to the third embodiment of the present invention. In the present embodiment, the same reference numerals are assigned to configurations common to those of the liquid crystal display devices according to the first embodiment and the second embodiment, and detailed description thereof is omitted.

  In the liquid crystal display device 300 of this embodiment, the pixel electrode 9 has a so-called multi-domain structure. That is, the extending direction of the slit Sc formed in the pixel electrode 9 is different between the half region on the side close to the scanning line 3a and the other half region on the side away from the scanning line 3a in the sub-pixel region. Yes. Of the plurality of slits Sc, the slit Sc formed in the half region on the side close to the scanning line 3a extends so as to be separated from the scanning line 3a as it is separated from the data line 6a. Further, the slit Sc formed in a half region on the side away from the scanning line 3a among the plurality of slits Sc extends so as to approach the scanning line 3a as the distance from the data line 6a increases. A curved portion is not formed in the slit Sc. Therefore, the slit Sc is formed only by the straight portion, and no curved portion is formed on the strip electrode 9c.

  In the case of this embodiment, the length of the slit Sc (the length in the direction parallel to the extending direction of the slit Sc) is formed equally in all the slits Sc. However, the intervals in the Y-axis direction between the slits are irregularly formed in the pixel electrode. Further, the width of the slit Sc (the width in the direction orthogonal to the slit Sc) and the angle formed by the slit Sc and the X axis are also irregularly formed in the pixel electrode 9. Therefore, when the length of the slit Sc is M and the angle between the slit Sc and the X axis is θ, an electrode pattern in which the angle θ is irregularly formed is formed in one pixel electrode.

  Although only one pixel electrode 9 is shown in FIG. 7, the shape of the pixel electrode 9 is common to each sub-pixel region. That is, the pixel electrode 9 includes an electrode pattern in which the angle θ is irregularly formed in one sub-pixel region, but a plurality of sub-pixels arranged in a matrix in the X-axis direction and the Y-axis direction. Between the regions, the electrode patterns of the pixel electrodes 9 are all formed equally.

  According to the liquid crystal display device 300 of the present embodiment, in the process of forming the pixel electrode 9, even if the shape of the pixel electrode slightly deviates from the target shape due to manufacturing errors, the angle θ originally varies irregularly. Therefore, deviation due to manufacturing errors is not noticeable. Therefore, uniform image quality can be obtained as a whole.

  In this embodiment, the angle θ is irregularly formed in one pixel electrode. However, instead of the angle θ, the ratio L / S between the width L of the strip electrode and the width S of the slit, and the length of the slit M may be formed irregularly, whereby the same effect as in the present embodiment can be obtained.

  Further, in this embodiment, the electrode pattern of the pixel electrode 9 is formed equally for all the pixel electrodes. However, the electrode pattern of the pixel electrode 9 is different for each pixel electrode 9 or for each unit region composed of a plurality of pixel electrodes 9. May be allowed.

For example, as shown in FIG. 5A, a plurality of types of electrode patterns in which at least one of the ratio L / S, the length M, or the angle θ is irregularly formed are prepared (FIG. 5A). Then, for each electrode pattern A ₁ , electrode pattern A ₂ , electrode pattern A ₃ ) and pixel electrode 9, one type of electrode pattern may be selected from among a plurality of types of electrode patterns A ₁ , A ₂ , A _3. . In this case, the types of electrode patterns to be selected are irregular between the pixel electrodes 9 adjacent along the X axis and between the pixel electrodes 9 adjacent along the Y axis.

Also, as shown in FIG. 5B, a plurality of types of electrode patterns in which at least one of the ratio L / S, the length M, or the angle θ is irregularly prepared are prepared (FIG. 5B). The electrode patterns A ₁ , A ₂ , and A ₃ ), and the unit areas constituted by the plurality of pixel electrodes 9 that are adjacent to each other in the plurality of types of electrode patterns A ₁ , A ₂ , and A ₃ . One type of electrode pattern may be selected. The types of electrode patterns of the plurality of pixel electrodes 9 arranged in one unit region are equal to each other, but between unit regions adjacent to each other along the X axis and between unit regions adjacent to each other along the Y axis Then, the types of electrode patterns to be selected are irregular.

  Further, as shown in FIG. 5C, electrode patterns in which at least one of the ratio L / S, the length M, or the angle θ is irregularly formed are prepared by the number of sub-pixel regions, The electrode patterns of the pixel electrodes may be different. In this case, at least one of the ratio L / S, the length M, or the angle θ is not between the adjacent strip electrodes along the X axis and between the adjacent strip electrodes along the Y axis. It will be formed into rules.

[Fourth Embodiment]
FIG. 8 is a plan configuration diagram in an arbitrary one sub-pixel region of the liquid crystal display device according to the fourth embodiment of the present invention. In the present embodiment, the same reference numerals are assigned to configurations common to those of the liquid crystal display devices according to the first embodiment and the second embodiment, and detailed description thereof is omitted.

  In the liquid crystal display devices from the first embodiment to the third embodiment, an electrode pattern in which slit shapes or arrangements are irregularly formed is formed in one pixel electrode. That is, when the width of the strip electrode is L, the width of the slit disposed between the adjacent strip electrodes is S, the length of the slit is M, and the angle between the strip electrode and the X axis is θ, The electrode was provided with an electrode pattern in which at least one of the ratio L / S, the length M, and the angle θ was irregularly formed. However, in the case of the configuration as shown in FIG. 5, the ratio L / S, the length M, and the angle θ are not necessarily irregularly formed in one pixel electrode.

For example, the electrode pattern A ₁ shown in FIG. 8A, the electrode pattern A ₂ shown in FIG. 8B, and the electrode pattern A ₃ shown in FIG. In addition, one type of electrode pattern is selected from among the electrode pattern A ₁ , the electrode pattern A ₂ , and the electrode pattern A ₃ . Then, as shown in FIG. 5A, the type of the electrode pattern selected between the pixel electrodes adjacent along the X axis and between the pixel electrodes adjacent along the Y axis is not specified. Form into rules.

The electrode pattern A ₁ , the electrode pattern A ₂ , and the electrode pattern A ₃ are different from each other in the ratio L / S. That is, in the electrode pattern _{A 1,} the width of the slit Sc S1, the width of the strip electrode 9c is L1, in one pixel electrode, the ratio L1 / S1 is formed at a fixed size. Further, the length M and the angle θ are equally formed in all the slits Sc. In the electrode patterns _{A 2,} the width of the slit Sc is S1, the width of the strip electrode 9c is L2 (<L1), in one pixel electrode, the ratio L2 / S1 is formed at a fixed size. Further, the length M and the angle θ are equally formed in all the slits Sc. In the electrode patterns _{A 3,} the width of the slit Sc is S1, the width of the strip electrode 9c is L3 (<L2), in one pixel electrode, the ratio L3 / S1 is formed at a fixed size. Further, the length M and the angle θ are equally formed in all the slits Sc.

  In FIG. 8, three electrode patterns having different ratios L / S are prepared, but the type of electrode pattern is not limited to this. That is, a plurality of types of electrode patterns different in at least one of the ratio L / S, the length M, and the angle θ are prepared, and one type of electrode pattern is selected from the plurality of types of electrode patterns for each pixel electrode. Just choose. Then, as shown in FIG. 5A, the type of the electrode pattern selected between the pixel electrodes adjacent along the X axis and between the pixel electrodes adjacent along the Y axis is not specified. Form into rules. It is sufficient that at least one of the ratio L / S, the length M, and the angle θ is different between different electrode patterns, and the ratio L / S, the length M, and the angle θ are irregular in the pixel electrode. It is not necessary to be formed.

  The electrode pattern as shown in FIG. 5B can be arranged using the same electrode pattern. That is, when a region composed of a plurality of pixel electrodes adjacent to each other is defined as a unit region, the types of electrode patterns of a plurality of pixel electrodes arranged in one unit region are equal to each other, and the X axis is The types of electrode patterns to be selected are irregularly formed between adjacent unit regions along the Y axis and between unit regions adjacent along the Y axis.

  Furthermore, the electrode pattern as shown in FIG. 5C can be arranged using the same electrode pattern. That is, it is possible to prepare as many electrode patterns as the number of sub-pixel regions and to change the electrode patterns of all the pixel electrodes. In this case, at least one of the ratio L / S, the length M, and the angle θ is set between the strip electrodes adjacent along the X axis and between the strip electrodes adjacent along the Y axis. Irregularly formed.

  In any case, in the process of forming the pixel electrode, even if the shape of the pixel electrode slightly deviates from the target shape due to manufacturing errors, the ratio L / S, the length M, Further, since at least one of the angles θ varies irregularly, a deviation due to a manufacturing error is not noticeable. Therefore, uniform image quality can be obtained as a whole.

[Electronics]
FIG. 9 is a perspective view of a mobile phone 1300 which is an example of the electronic apparatus of the present invention. A cellular phone 1300 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. Since the mobile phone 1300 includes the liquid crystal display device according to the above-described embodiment, it is possible to display an image having uniform image quality.

  The liquid crystal display device of the above embodiment 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, It can be suitably used as an image display means for devices such as electronic notebooks, calculators, word processors, workstations, videophones, POS terminals, touch panels, etc., and any electronic device can display images with uniform image quality. It is.

1 is an equivalent circuit diagram of a liquid crystal display device of a first embodiment. It is a top view of 1 sub pixel of a liquid crystal display device. It is AA 'sectional drawing of FIG. It is explanatory drawing of the arrangement | positioning relationship of the optical axis of a liquid crystal display device. It is a plane schematic diagram which shows the variation of arrangement | positioning of an electrode pattern. It is a top view of 1 sub pixel of the liquid crystal display device of 2nd Embodiment. It is a top view of 1 sub pixel of the liquid crystal display device of 3rd Embodiment. It is explanatory drawing of the electrode pattern of the liquid crystal display device of 4th Embodiment. It is a perspective view of the mobile phone which is an example of an electronic device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 9 ... Pixel electrode (2nd electrode), 9c ... Band-shaped electrode, 10 ... TFT array substrate, 13 ... 2nd interlayer insulation film, 19 ... Common electrode (1st electrode), 20 ... Opposite substrate, 50 ... Liquid crystal layer, 100 , 200, 300 ... Liquid crystal display device, 1300 ... Mobile phone (electronic equipment)

Claims (9)

A pair of opposing substrates, a liquid crystal layer sandwiched between the pair of substrates, a first electrode provided on the liquid crystal layer side of one of the pair of substrates, and the one of the one substrate A plurality of second electrodes opposed to each other on the first electrode via an insulating film on the liquid crystal layer side, and the plurality of second electrodes are arranged with a first arrangement axis and a second arrangement axis perpendicular to each other. A liquid crystal display device arranged two-dimensionally on the one substrate along the line,
The second electrode is provided with a plurality of strip electrodes,
The width of the strip electrode is L, the width of the slit disposed between adjacent strip electrodes is S, the length of the slit is M, and the angle between the strip electrode and the first array axis is θ. In some cases, the second electrode includes an electrode pattern in which at least one of a ratio L / S, a length M, and an angle θ is irregularly formed. For each of the second electrodes, one kind of electrode pattern is selected from a plurality of kinds of electrode patterns in which at least one of the ratio L / S, the length M, and the angle θ is irregularly formed,
The types of electrode patterns selected between the second electrodes adjacent along the first array axis and between the second electrodes adjacent along the second array axis are irregular. The liquid crystal display device according to claim 1. For each of the second electrodes, one kind of electrode pattern is selected from a plurality of kinds of electrode patterns in which at least one of the ratio L / S, the length M, and the angle θ is irregularly formed,
When a region composed of a plurality of second electrodes adjacent to each other is defined as a unit region, the types of electrode patterns of the plurality of second electrodes arranged in one unit region are equal to each other and the first arrangement The type of electrode pattern selected between the unit regions adjacent along the axis and between the unit regions adjacent along the second array axis is irregular. A liquid crystal display device according to 1. A pair of opposing substrates, a liquid crystal layer sandwiched between the pair of substrates, a first electrode provided on the liquid crystal layer side of one of the pair of substrates, and the one of the one substrate A plurality of second electrodes opposed to each other on the first electrode via an insulating film on the liquid crystal layer side, and the plurality of second electrodes are arranged with a first arrangement axis and a second arrangement axis perpendicular to each other. A liquid crystal display device arranged two-dimensionally on the one substrate along the line,
The second electrode is provided with a plurality of strip electrodes,
The width of the strip electrode is L, the width of the slit disposed between adjacent strip electrodes is S, the length of the slit is M, and the angle between the strip electrode and the first array axis is θ. Sometimes, for each of the second electrodes, one type of electrode pattern is selected from a plurality of types of electrode patterns that differ in at least one of the ratio L / S, the length M, and the angle θ,
The types of electrode patterns selected between the second electrodes adjacent along the first array axis and between the second electrodes adjacent along the second array axis are irregular. A characteristic liquid crystal display device. A pair of opposing substrates, a liquid crystal layer sandwiched between the pair of substrates, a first electrode provided on the liquid crystal layer side of one of the pair of substrates, and the one of the one substrate A plurality of second electrodes opposed to each other on the first electrode via an insulating film on the liquid crystal layer side, and the plurality of second electrodes are arranged with a first arrangement axis and a second arrangement axis perpendicular to each other. A liquid crystal display device arranged two-dimensionally on the one substrate along the line,
The second electrode is provided with a plurality of strip electrodes,
The width of the strip electrode is L, the width of a slit disposed between adjacent strip electrodes is S, the length of the slit is M, and the angle formed by the strip electrode and the first array axis is θ. Sometimes, for each of the second electrodes, one type of electrode pattern is selected from a plurality of types of electrode patterns that differ in at least one of the ratio L / S, the length M, and the angle θ,
When a region composed of a plurality of second electrodes adjacent to each other is defined as a unit region, the types of electrode patterns of the plurality of second electrodes arranged in one unit region are equal to each other and the first arrangement The type of electrode pattern selected between unit areas adjacent along the axis and between unit areas adjacent along the second array axis is irregular. . A pair of opposing substrates, a liquid crystal layer sandwiched between the pair of substrates, a first electrode provided on the liquid crystal layer side of one of the pair of substrates, and the one of the one substrate A plurality of second electrodes opposed to each other on the first electrode via an insulating film on the liquid crystal layer side, and the plurality of second electrodes are arranged with a first arrangement axis and a second arrangement axis perpendicular to each other. A liquid crystal display device arranged two-dimensionally on the one substrate along the line,
The second electrode is provided with a plurality of strip electrodes,
The width of the strip electrode is L, the width of the slit disposed between adjacent strip electrodes is S, the length of the slit is M, and the angle between the strip electrode and the first array axis is θ. Sometimes, the ratio L / S, the length M, and the angle θ between the strip electrodes adjacent along the first array axis and between the strip electrodes adjacent along the second array axis. A liquid crystal display device, wherein at least one of them is irregularly formed.   6. The liquid crystal display region according to claim 3, wherein the number of the second electrodes included in one unit region is 10 or less.   The liquid crystal display device according to claim 2, wherein the number of types of the electrode patterns is three or more.   An electronic apparatus comprising the liquid crystal display device according to claim 1.

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