JP3973677B2 - Liquid crystal display - Google Patents

Description

  The present invention relates to a liquid crystal display device such as a television or a display. In particular, the present invention relates to a liquid crystal display device including a vertically aligned liquid crystal.

  The liquid crystal display device includes a liquid crystal inserted between a pair of substrates. Each of the pair of substrates has an electrode and an alignment film. Conventionally used TN liquid crystal display devices include a horizontal alignment film and a liquid crystal having positive dielectric anisotropy, and the liquid crystal is aligned substantially parallel to the horizontal alignment film when no voltage is applied. . When a voltage is applied, the liquid crystal rises substantially perpendicular to the horizontal alignment film.

  The TN liquid crystal display device has the advantage that it can be thinned, but has the disadvantage that the viewing angle is narrow. There is alignment division as a method for improving this defect and achieving a wide viewing angle. The alignment division divides one pixel into two regions so that the liquid crystal rises and falls toward one side in one region, and the liquid crystal rises and falls toward the opposite side in the other region. A wide viewing angle is obtained by averaging the behavior of the liquid crystal in the pixel.

  In order to control the alignment of the liquid crystal, the alignment film is usually rubbed. In the case of performing alignment division, one region of one pixel is rubbed in the first direction using a mask, and then the other region of one pixel is defined as the first direction using a complementary mask. Rub in the opposite second direction. Alternatively, the entire alignment film is rubbed in the first direction, and a mask is used to selectively irradiate one region or the other region of one pixel with ultraviolet rays, and the liquid crystal pretilt is performed in one region and the other region. To make a difference.

  In a liquid crystal display device using a horizontal alignment film, it is necessary to perform rubbing, and it is necessary to clean the substrate provided with the alignment film after rubbing. Therefore, the production of the liquid crystal panel is relatively troublesome, and contamination may occur during rubbing.

  On the other hand, in a liquid crystal display device using a vertical alignment film, the liquid crystal is aligned substantially perpendicular to the vertical alignment film when no voltage is applied, and the liquid crystal is approximately horizontal to the vertical alignment film when a voltage is applied. Fall down. Even in a liquid crystal display device using a vertical alignment film, the alignment film is usually rubbed in order to control the alignment of the liquid crystal.

  Japanese Patent Application No. 10-185836 by the applicant of the present application proposes a liquid crystal display device capable of controlling the alignment of the liquid crystal without rubbing. This liquid crystal display device is a vertical alignment type liquid crystal display device having a vertical alignment film and a liquid crystal having negative dielectric anisotropy, and is an alignment control provided on each of a pair of substrates for controlling the alignment of the liquid crystal. A structure (a linear structure including protrusions or slits) is provided.

  In this vertical alignment type liquid crystal display device, there is an advantage that alignment is not required by rubbing and alignment division can be achieved by the arrangement of linear structures. Therefore, this vertical alignment type liquid crystal display device can obtain a wide viewing angle and high contrast. Since it is not necessary to perform rubbing, cleaning after rubbing is not required. Therefore, the liquid crystal display device can be easily manufactured, there is no contamination during rubbing, and the reliability of the liquid crystal display device is improved.

Other conventional liquid crystal display devices include linear slits or protrusions formed on electrodes (see, for example, Patent Document 1, Patent Document 2, and Patent Document 3). In some cases, protrusions are used to regulate the alignment direction of the liquid crystal (see, for example, Patent Document 4 and Non-Patent Document 1). In addition, there is a liquid crystal display device including a protruding portion formed outside the pixel region (see, for example, Patent Document 5).
US Pat. No. 6,710,837 US Pat. No. 6,567,144 Korean Published Patent Publication No. 1999-085616 JP 7-199193 A European Patent Application No. 0854377 A. Takeda et. Al. "A Super-High-Image-Quality Multi-Domain Vertical Alignment LCD by New Rubbing-Less Technology" SID 98 DIGEST, 1998/5/17, p.1077-1080

  In a vertical alignment type liquid crystal display device having an alignment regulating structure (a structure including protrusions or slits) on a pair of substrates in order to control the alignment of liquid crystal, an unstable region of alignment of liquid crystal molecules exists, It was found that there is a problem to be further improved as will be described later on the response speed.

  An object of the present invention is to provide a vertical alignment type liquid crystal display device capable of further improving luminance and response speed.

The liquid crystal display device according to the present invention is a liquid crystal display device having a plurality of pixels, and includes a first substrate, a second substrate provided to face the first substrate, the first substrate, and the second substrate. The first substrate includes a linear first structure body, a second structure body, and an auxiliary structure body that control alignment of liquid crystal, and the second substrate includes: , Including a linear third structure and a fourth structure for controlling the alignment of the liquid crystal, and the first structure, the second structure, and the auxiliary structure are different from each other in one pixel. The third structure extends in the pixel in parallel with the first structure, and the fourth structure extends in the pixel in parallel with the second structure. The second structure body, the third structure body, and the fourth structure body all have a direction in which the edge of the pixel extends. Extend in different directions.

In one embodiment, the first structure body and the second structure body are continuously formed via a bent portion. In one embodiment, the auxiliary structure extends to the obtuse angle side of the bent portion .

In one embodiment, the auxiliary structure extends in a direction that bisects an angle between a direction in which the first structure extends and a direction in which the second structure extends .

In one embodiment, the auxiliary structure extends to an acute angle side of the bent portion .

In one embodiment, the auxiliary structure extends in a direction that bisects an angle between a direction in which the first structure extends and a direction in which the second structure extends .

In one embodiment, the first substrate has a common electrode, and the first structure and the second structure are projections formed on the common electrode or slits formed on the common electrode. There is .

In one embodiment, the auxiliary structure is a protrusion formed on the common electrode or a slit formed on the common electrode .

In one embodiment, the second substrate includes a second auxiliary structure that is a structure that controls alignment of liquid crystal and extends in a direction different from that of the third structure and the fourth structure .

In one embodiment, the second substrate has a pixel electrode, and the third structure, the fourth structure, and the second auxiliary structure are protrusions formed on the pixel electrode, or It is a slit formed in the pixel electrode .

In one embodiment, an angle between a direction in which the first structure extends and a direction in which the second structure extends is about 90 ° .

  According to the present invention, it is possible to manufacture a liquid crystal display device with improved luminance and quick response speed. The orientation direction of all the domains formed on the linear structure can be determined, and the change with time of the domains can be suppressed, so that overshoot can be improved.

  Examples of the present invention will be described below. FIG. 1 is a schematic sectional view showing a liquid crystal display device according to the present invention. In FIG. 1, the liquid crystal display device 10 includes a pair of transparent glass substrates 12 and 14 and a liquid crystal 16 inserted between the glass substrates 12 and 14. The liquid crystal 16 is a liquid crystal having negative dielectric anisotropy. The first glass substrate 12 has an electrode 18 and a vertical alignment film 20, and the second glass substrate 14 has an electrode 22 and a vertical alignment film 24. Further, a polarizing plate 26 is disposed outside the first glass substrate 12, and a polarizing plate 28 is disposed outside the second glass substrate 14. Here, for simplification of description, the first glass substrate 12 is referred to as an upper substrate, and the second glass substrate 14 is referred to as a lower substrate.

  When the upper substrate 12 is configured as a color filter substrate, the upper substrate 12 further includes a color filter and a black mask. In this case, the electrode 18 is a common electrode. Further, when the lower substrate 14 is configured as a TFT substrate, the lower substrate 12 includes an active matrix driving circuit together with the TFT. In this case, the electrode 22 is a pixel electrode.

  FIG. 2 is a schematic cross-sectional view showing a vertical alignment type liquid crystal display device having an alignment regulating structure for controlling the alignment of liquid crystal. For simplicity, the electrodes 18 and 22 and the alignment films 20 and 24 of FIG. 1 are omitted in FIG. In FIG. 2, the upper substrate 12 has a protrusion 30 that protrudes toward the lower substrate 14 as an alignment regulating structure. Similarly, the lower substrate 14 has a protrusion 32 that protrudes toward the upper substrate 12 as an alignment regulating structure. The protrusions 30 and 32 extend in a line shape that is long and perpendicular to the paper surface of FIG.

  FIG. 3 is a plan view of the protrusions 30 and 32 as seen from the direction of arrow III in FIG. FIG. 3 further shows a portion of one pixel of the active matrix driving circuit. The active matrix driving circuit includes a gate bus line 36, a drain bus line 38, a TFT 40, and a pixel electrode 22. The protrusion 30 of the upper substrate 12 passes through the center of the pixel electrode 22, and the protrusion 32 of the lower substrate 12 passes through the gate bus line 36. Thus, the protrusions 30 and 32 extend alternately and in parallel in the plan view seen from above. However, the example shown in FIG. 3 is a very simple example, and the arrangement of the protrusions 30 and 32 is not limited to such an example.

  As shown in FIG. 2, when the liquid crystal 16 having negative dielectric anisotropy is disposed between the vertical alignment films 20 and 24, the liquid crystal molecules 16 </ b> A are formed on the vertical alignment films 20 and 24 when no voltage is applied. It is oriented vertically with respect to it. In the vicinity of the protrusions 30 and 32, the liquid crystal molecules 16 </ b> B are aligned perpendicular to the protrusions 30 and 32. Since the protrusions 30 and 32 include an inclination, the liquid crystal molecules 16B aligned perpendicular to the protrusions 30 and 32 are obliquely aligned with respect to the vertical alignment films 20 and 24.

  When a voltage is applied to the liquid crystal 16, the liquid crystal 16 having negative dielectric anisotropy is oriented in a direction perpendicular to the electric field, so that the liquid crystal molecules are tilted almost in parallel to the substrate surface (vertical alignment films 20, 24). become. Normally, unless the vertical alignment films 20 and 24 are rubbed, the direction in which the liquid crystal molecules are tilted is not fixed and the behavior of the liquid crystal is not stable. However, when there are protrusions 30 and 32 extending in parallel with each other as in the present invention, the liquid crystal molecules 16B in the vicinity of these protrusions 30 and 32 are oblique to the vertical alignment films 20 and 24 as if they were pretilted. Therefore, the direction in which the liquid crystal molecules 16B are tilted is determined when a voltage is applied.

  For example, when viewing the liquid crystal molecules between the left protrusion 30 and the lower left protrusion 32 of the upper substrate 14 in FIG. 2, the liquid crystal molecules 16B between the protrusions 30 and 32 are aligned from the upper right to the lower left. Therefore, the liquid crystal molecules 16B are tilted in parallel to the vertical alignment films 20 and 24 while rotating clockwise when a voltage is applied. Accordingly, the liquid crystal molecules 16A between the protrusions 30 and 32 are tilted in parallel with the vertical alignment films 20 and 24 while rotating clockwise according to the behavior of the liquid crystal molecules 16B. Similarly, for the liquid crystal molecules between the left protrusion 30 and the lower right protrusion 32 of the upper substrate 14 of FIG. 2, the liquid crystal molecules 16B between the protrusions 30 and 32 are aligned from the upper left to the lower right. Therefore, when a voltage is applied, the liquid crystal molecules 16B are tilted in parallel to the vertical alignment films 20 and 24 while rotating counterclockwise. Accordingly, the liquid crystal molecules 16A between the protrusions 30 and 32 are tilted in parallel to the vertical alignment films 20 and 24 while rotating counterclockwise according to the behavior of the liquid crystal molecules 16B.

  FIG. 4 is a diagram showing the liquid crystal molecules 16A that are tilted when a voltage is applied according to the arrangement of the protrusions 30 and 32 of FIGS. 4A is a plan view, and FIG. 4B is a cross-sectional view taken along line IVB-IVB. The liquid crystal molecules 16A on one side of the protrusions 30 on the upper substrate 12 fall while rotating clockwise (in the direction of the arrow X) toward the protrusions 30, and the liquid crystal molecules 16A on the other side of the protrusions 30 on the upper substrate 12 It falls down while rotating counterclockwise (in the direction of arrow Y). In FIG. 4, when no voltage is applied, the liquid crystal molecules 16A are aligned perpendicular to the paper surface of FIG. In this way, the alignment of the liquid crystal can be controlled without rubbing, and a plurality of regions having different alignment directions of the liquid crystal molecules can be formed within one pixel. A display device can be realized.

  FIG. 5 is a plan view showing another example of the protrusions (orientation regulating structures) 30 and 32. The protrusions 30 and 32 extend parallel to each other and bend. That is, the protrusions 30 and 32 are bent in a meandering manner while being parallel. In this example, the liquid crystal molecules 16C and 16D on both sides of the small portions of the protrusions 30 and 32 are oriented opposite to each other, and the liquid crystal molecules 16E and 16F on both sides of the small portions next to the protrusions 30 and 32 are bent. Are oriented opposite to each other. The liquid crystal molecules 16C and 16D are rotated 90 degrees with respect to the liquid crystal molecules 16E and 16F. Therefore, alignment division is achieved in which four regions with different liquid crystal alignments are formed in one pixel, and viewing angle characteristics are further improved.

  FIG. 6 is a diagram schematically showing a liquid crystal display device in which the alignment regulating structures are both protrusions 30 and 32. In FIG. 6, the electrode 18 provided on the upper substrate 12 and the electrode 22 provided on the lower substrate 14 are shown. The protrusions 30 and 32 are formed as dielectrics on the electrodes 18 and 22. Reference numeral 42 denotes an electric field near the protrusions 30 and 32. Since the protrusions 30 and 32 are dielectrics, the electric field 42 in the vicinity of the protrusions 30 and 32 becomes an oblique electric field, and when a voltage is applied, the liquid crystal molecules are tilted so as to be perpendicular to the electric field 42 as indicated by arrows. . The direction in which the liquid crystal molecules are tilted by the oblique electric field is the same as the direction in which the liquid crystal molecules are tilted due to the inclined surfaces of the protrusions 30 and 32.

  FIG. 7 is a schematic cross-sectional view showing a liquid crystal display device when the alignment regulating structure of the lower substrate 14 is a protrusion 32 and the alignment regulating structure of the upper substrate 12 is a slit structure 44. The slit structure 44 includes a slit of the electrode 18 of the upper substrate 12. Actually, since the vertical alignment film 20 (not shown in FIG. 7) covers the electrode 18 having the slit, the vertical alignment film 20 is depressed at the position of the slit of the electrode 18. The slit structure 44 includes a slit of the electrode 18 and a recessed portion of the vertical alignment film 20. And such a slit structure 44 is extended linearly similarly to the protrusion 30 of FIG.

  In the vicinity of the slit structure 44, an oblique electric field 42 is formed between the electrode 18 of the upper substrate 12 and the electrode 22 of the lower substrate 14. The oblique electric field 42 is the same as the oblique electric field 42 formed in the vicinity of the protrusion 30 in FIG. 6, and the liquid crystal molecules are tilted according to the oblique electric field 42 when a voltage is applied. In this case, the manner in which the liquid crystal molecules fall is the same as the manner in which the liquid crystal molecules fall when the protrusions 30 are present. Accordingly, the alignment of the liquid crystal can be controlled by the combination of the slit structure 44 and the protrusion 32, as in the case of controlling the alignment of the liquid crystal by the combination of the protrusion 30 and the protrusion 32 as shown in FIG.

  FIG. 8 is a schematic cross-sectional view showing a liquid crystal display device when the alignment regulating structures of the upper substrate 12 and the lower substrate 14 are both slit structures 4446. The slit structure 44 extends linearly in the same manner as the protrusion 30 in FIG. 6, and the slit structure 46 extends linearly in the same manner as the protrusion 32 in FIG. In the vicinity of the slit structures 44 and 46, an oblique electric field 42 is formed between the electrode 18 of the upper substrate 12 and the electrode 22 of the lower substrate 14. The oblique electric field 42 is the same as the oblique electric field 42 formed in the vicinity of the protrusions 30 and 32 in FIG. 6, and the liquid crystal molecules are tilted according to the oblique electric field 42 when a voltage is applied. In this case, the manner in which the liquid crystal molecules fall is the same as the manner in which the liquid crystal molecules fall when the protrusions 30 and 32 are present. Therefore, the alignment of the liquid crystal can be controlled by the combination of the slit structures 44 and 46 in the same manner as the alignment of the liquid crystal is controlled by the combination of the protrusion 30 and the protrusion 32 as shown in FIG.

  Therefore, the protrusions 30 and 32 and the slit structures 44 and 46 can similarly control the alignment of the liquid crystal. The protrusions 30 and 32 and the slit structures 44 and 46 can be understood by a common concept as an alignment regulation structure (or a linear alignment regulation structure).

  FIG. 9 is a cross-sectional view showing a linear structure which is the protrusion 30 (32). The protrusion 30 is formed as follows, for example. An electrode 22 is formed on the lower substrate 14 together with an active matrix. A dielectric 30A to be a protrusion is formed on the electrode 22. The dielectric 30A is formed by applying a resist and patterning. A vertical alignment film 24 is formed on the dielectric 30 </ b> A and the electrode 22. In this way, the protrusion 30 is formed.

  FIG. 10 is a sectional view showing an example of a linear wall structure which is the slit structure 44 (46). The slit structure 44 is formed as follows, for example. After forming a color filter, a black mask or the like on the upper substrate 14, an electrode 18 is formed. The electrode 18 is patterned to form a slit 18A. A vertical alignment film 20 is formed on the electrode 18 having the slit 18A. In this way, the slit structure 44 is formed.

  FIG. 11 is a diagram for explaining a problem of alignment of a liquid crystal display device having a linear structure. Hereinafter, the linear structure is mainly described as the protrusions 30 and 32, but the same applies to slit structures (sometimes simply referred to as slits) 44 and 46 instead of the protrusions 30 and 32.

  11 shows a state similar to FIG. 4 (however, FIG. 4 shows only the liquid crystal molecules 16A in the gap between the protrusions 30 and 32, and FIG. 11 shows the gap in the gap between the protrusions 30 and 32. The liquid crystal molecules 16A and the liquid crystal molecules above and in the vicinity of the protrusions 30 and 32 are shown, and the protrusion 32 of the lower substrate 14 is positioned at the center in FIG. Reference numeral 48 denotes the arrangement of the polarizing plates 26 and 28. The polarizing plates 26 and 28 are disposed at an angle of 45 degrees with respect to the protrusions 30 and 32.

  As described above, the liquid crystal molecules 16A in the gap between the protrusions 30 and 32 when voltage is applied are perpendicular to the protrusions 32 on both sides of the protrusions 32 on the lower substrate (or the protrusions 30 on the upper substrate 12) and Sleep in opposite directions. The liquid crystal molecules on and in the vicinity of the protrusions 30 and 32 lie between these liquid crystal molecules 16A sleeping in opposite directions, and sleep while continuing to these liquid crystal molecules 16A. All the liquid crystal molecules are aligned in a plane parallel to the paper surface of FIG. In this case, the liquid crystal molecules located directly above the protrusions 32 may fall to the right in FIG. 11 and may fall to the left. However, it is not certain whether the liquid crystal molecules located directly above the protrusions 32 tilt to the right or to the left. Therefore, the alignment state in which the liquid crystal molecules are tilted to the right on the same protrusion 32 and the alignment state in which the liquid crystal molecules are tilted to the left are mixed, and the liquid crystal molecules are in contact with each other when the two alignment states are in contact with each other. The boundary of the orientation is made. Such a plurality of boundaries exist on one protrusion 32.

  In addition, when the alignment state of the liquid crystals is the same on the protrusions 30 and 32 of the upper and lower substrates 12 and 14 as shown in FIG. 11 (for example, the region C), the alignment between the protrusions 30 and 32 is a bend alignment. When the alignment state of the liquid crystals is different on the protrusions 30 and 32 of the substrates 12 and 14 (for example, the region A), the alignment between the protrusions 30 and 32 is a splay alignment. That is, two alignment states are mixed between the protrusions 30 and 32, and a boundary is formed between regions having different alignment states.

  Further, when these alignment states are examined in detail, the alignment states are slightly different even in the case of, for example, spray alignment due to misalignment between the upper and lower substrates 12 and 14. For this reason, the angles of the polarizing plates 26 and 28 at which the transmittance is maximum differ in each region. This state was actually measured by rotating the polarizing plates 26 and 28 in several regions. In FIG. 11, the region A shows that the polarizing plates 26 and 28 are rotated by −13 degrees with respect to the normal arrangement 48. In the region B, the polarizing plates 26 and 28 are rotated by −4 degrees with respect to the normal arrangement 48. In region C, the polarizing plates 26 and 28 are rotated +2 degrees with respect to the normal arrangement 48.

  FIG. 12 is a diagram showing the transmittance measured in regions A, B, and C of FIG. Curve A shows the measurement result in region A in FIG. 11, curve B shows the measurement result in region B in FIG. 11, and curve C shows the measurement result in region C in FIG. The curve A shows that a considerably high transmittance is obtained at an angle far from the normal arrangement 48 (45 degrees with respect to the protrusions 30 and 32) of the polarizing plates 26 and 28, but the normal arrangement 48 of the polarizing plates 26 and 28 is obtained. When it is at 45 degrees with respect to the protrusions 30 and 32, it indicates that almost no light can be transmitted. Curve B shows that the polarizing plates 26 and 28 can obtain a relatively high transmittance at an angle slightly deviated from the normal arrangement 48 (45 degrees with respect to the protrusions 30 and 32). A curve C indicates that a certain degree of transmittance can be obtained when the polarizing plates 26 and 28 are in a normal arrangement 48 (45 degrees with respect to the protrusions 30 and 32). Thus, when the protrusions 30 and 32 are used, a plurality of regions having different transmittance characteristics are formed.

  FIG. 13 is a diagram showing a change in transmittance after voltage application. When regions having different alignment states as described with reference to FIGS. 11 and 12 exist, a phenomenon called overshoot occurs immediately after voltage application. That is, after applying a voltage, the transmittance becomes very high, for example, at 1000 ms, and then the transmittance gradually decreases and becomes balanced at a predetermined value. The overshoot is expressed by how much the white luminance is increased from the transmittance in the equilibrium state. When the initial luminance is X and the balanced luminance is Y, the overshoot (%) is defined as (Y−X) / X × 100.

  As shown in FIG. 11, when there are regions A, B, and C having different transmittances, the liquid crystals in these regions A, B, and C continue to move in each region after voltage application, and the liquid crystals in adjacent regions While affecting each other, the regions A, B, and C continue to move (the boundaries between the regions A, B, and C move), thereby increasing the transmittance and increasing the overshoot. Overshoot also causes afterimages and degrades display quality. In addition, if there are regions A, B, and C having different characteristics, a difference in display performance occurs, and a certain quality cannot be obtained.

  Therefore, it is desirable to control the alignment state of the liquid crystal on the protrusions 30 and 32 to prevent the liquid crystal in the region having different transmittance from continuing to move forever, thereby improving the luminance and the response speed.

  FIG. 14 is a diagram showing an example of the protrusions (linear structures) 30 and 32 according to the first embodiment of the present invention. It goes without saying that the slit structures 44 and 46 may be used instead of the protrusions 30 and 32 as a linear structure.

  As described above, the liquid crystal display device has the protrusion 30 of the upper substrate 12 and the protrusion 32 of the lower substrate. Each protrusion 30 and 32 is formed of a plurality of structural units 30S and 32S. The structural units 30S and 32S have a substantially uniform shape and are separated from each other by a change in shape or cutting. In the example of FIG. 14, two adjacent structural units 30S and 32S are connected at a narrowed portion. Further, the structural unit 30S of the protrusion 30 of the upper substrate 12 and the structural unit 32S of the protrusion 32 of the lower substrate 14 extend in parallel to each other and are arranged at positions overlapping each other.

  Thus, since each protrusion 30 and 32 is formed from a plurality of structural units 30S and 32S, a plurality of regions A, B and C having different transmittances as shown in FIG. 11 in each of the structural units 30S and 32S. Is less likely to form. Also, such regions A, B, and C do not continue to move (the boundaries between regions A, B, and C do not continue to move), and the time until the liquid crystal is stably aligned in a horizontal state Get faster. Thereby, the overshoot is reduced, and the luminance can be improved and the response speed can be improved. Even if there is a region where the transmittance loss is large, if there are many regions where the transmittance loss is small, the influence can be counteracted. For this purpose, each of the protrusions 30 and 32 preferably includes as many structural units 30S and 32S as possible. Preferably, the length of the structural units 30S and 32S is not less than the value of the gap between the protrusions 30 and 32 of the pair of substrates 12 and 14, and not more than 200 μm.

  FIG. 15 is a view showing a modified example of the protrusions 30 and 32. Each protrusion 30 and 32 is formed of a plurality of structural units 30S and 32S. In this example, the protrusions 30 and 32 are cut, that is, the structural units 30S and 32S are separated from each other. Other features are the same as in the example of FIG.

  FIG. 16 is a view showing a modified example of the protrusions 30 and 32. Each protrusion 30 and 32 is formed of a plurality of structural units 30S and 32S. In this example, the protrusions 30 and 32 are formed in a bent shape. Other features are the same as in the example of FIG.

  FIG. 17 is a view showing a modification of the protrusions 30 and 32. Each protrusion 30 and 32 is formed of a plurality of structural units 30S and 32S. In this example, the protrusions 30 and 32 are cut, that is, the structural units 30S and 32S are separated from each other. Further, the structural unit 30S of the protrusion 30 of the upper substrate 12 and the structural unit 32S of the protrusion 32 of the lower substrate 14 are disposed in positions that extend in parallel with each other and are shifted from each other. This is convenient because the number of domains further increases. Of course, even when the structural units are in contact as shown in FIG. 14, the structural units 30S and 32S constituting the protrusions 30 and 32 of the upper and lower substrates may be shifted as shown in FIG.

  FIG. 18 is a view showing a modified example of the protrusions 30 and 32. Each protrusion 30 and 32 is formed of a plurality of structural units 30S and 32S. In this example, the protrusions 30 and 32 are cut, that is, the structural units 30S and 32S are separated from each other. Further, the structural unit 30S of the protrusion 30 of the upper substrate 12 and the structural unit 32S of the protrusion 32 of the lower substrate 14 are different in length. The length of the structural unit 30S of the protrusion 30 of the upper substrate 12 is approximately three times the length of the structural unit 32S of the protrusion 32 of the lower substrate 14. The center of the structural unit 30S of the protrusion 30 of the upper substrate 12 coincides with the center of the three structural units 32S of the protrusion 32 of the lower substrate 14.

  FIG. 19 is a view showing a modification of the protrusions 30 and 32. Each protrusion 30 and 32 is formed of a plurality of structural units 30S and 32S. In this example, the protrusions 30 and 32 are cut, that is, the structural units 30S and 32S are separated from each other. Furthermore, the structural units 30S of the protrusions 30 of the upper substrate 12 have different lengths, and the structural units 32S of the protrusions 32 of the lower substrate 14 have different lengths. In this example, the structural units 30S and 32S are each composed of two types of lengths, and the units having different lengths are alternately arranged as a set. The set of structural units 30S of the protrusions 30 of the upper substrate 12 and the set of structural units 32S of the protrusions 32 of the lower substrate 14 are further shifted in position. The structural units 30S and 32S in FIGS. 18 and 19 can be arranged at the same position as in the previous embodiment, or can be formed in a connected shape.

  FIG. 20 is a view showing a modification of the protrusions 30 and 32. Each protrusion 30 and 32 is formed of a plurality of structural units 30S and 32S. In this example, the structural unit 30S of the protrusion 30 is disposed so as to jump over every other structural unit 32S of the protrusion 32, and the structural unit 32S of the protrusion 32 is disposed so as to jump over the structural unit 30S of the protrusion 30. For example, the structural unit 30S is arranged so that every other structural unit 30S of the protrusion 30 on the upper substrate jumps to the position of the protrusion 30 in FIG. 2, and the structural unit 32S of the protrusion 32 on the lower substrate is the protrusion 30 of FIG. It is arranged so as to jump every other position at a position immediately below the constituent unit 30S of the protrusion 30 of the upper substrate. Apparently, it appears that the structural units 30S and 32S of the protrusions 30 and 32 on the upper and lower substrates form a row of structural units.

  In the above example, the structural units 30S and 32S of the protrusions 30 and 32 are shown in an elliptical shape, but the shape is not limited to this, and the shape may be a rectangle, a rhombus, or other polygons. Further, the lengths of the structural units 30S and 32S of the protrusions 30 and 32 are preferably set to a length obtained by grouping R, G, and B pixels, that is, 200 μm or less for the purpose of averaging. In addition, since the protrusion gap when the pair of substrates are overlapped becomes the minimum distance for controlling the alignment of the liquid crystal, it is desirable that the lengths of the structural units 30S and 32S of the protrusions 30 and 32 are longer than the protrusion gap.

  So far, the case of the protrusions 30 and 32 has been described, but the above also applies to the case of the slit structures 44 and 46 including the slits of the electrodes. That is, the slit may be composed of a plurality of structural units. In this case, the arrangement described above can be used as it is. In addition, the restriction on the length of the structural unit is the same.

  FIG. 21 is a diagram showing a modification of the linear structure. FIG. 21 shows three pixel electrodes 22R, 22G, and 22B, and the linear structure has the bent shape shown in FIG. The linear structure of the upper substrate 12 is composed of protrusions 30, and the linear structure of the lower substrate 14 is composed of slit structures 46. That is, the linear structure shown in FIG. 21 corresponds to the projection and slit structure shown in FIG.

  FIG. 22 is a diagram showing the pixel electrode 22R and the slit structure 46 of FIG. The pixel electrode 22R has a plurality of slits 22S and a portion 22T made of the same material (ITO) as the pixel electrode 22R located between adjacent slits 22S. The slit 22S can be formed when the pixel electrode 22R is patterned. When the vertical alignment film 24 is applied on the pixel electrode 22R, the series of slits 22S of the pixel electrode 22R becomes the slit structure 46, and the slit 22S becomes the constituent unit 46S of the slit structure 46. The material portion 22T is a portion separating adjacent structural units 46S.

  In the example, the width of the slit 22S (the structural unit 46S of the slit structure 46) was 5 μm, and the length was 12 μm, 26 μm, and 33 μm. The length of the slit 22S (the structural unit 46S of the slit structure 46) is desirably 10 μm or more. The length of the material portion 22T was 4 μm. The length of the material portion 22T is preferably equal to or less than the width of the protrusion 30. Similarly, the width of the structural unit 30S of the protrusion 30 was 5 μm, and the lengths were 12 μm, 26 μm, and 33 μm. The length of the gap between the structural units 30S of the protrusion 30 was 4 μm.

  FIG. 23 is a diagram for explaining the formation of a linear structure including the protrusions 30. As shown in (A), a substrate 12 is prepared, and a color filter, a black mask, and an electrode 18 are applied. As shown in (B), the substrate 12 having the electrodes 18 (not shown) is spin-coated with a positive resist 50 LC200 (manufactured by Shibley) at 1500 rpm for 30 s. Although a positive resist is used here, it is not necessarily a positive resist, a negative resist may be used, and a photosensitive resin other than a resist may be used. As shown in (C), after spin-coating the spin-coated resist 50 at 90 ° C. for 20 minutes, contact exposure was performed through a photomask 52 (exposure time 5 s). Next, as shown in (D), development was performed with a developer manufactured by Sibley (development time 1 minute), and then post-baking was performed at 120 ° C. for 60 minutes and then at 200 ° C. for 40 minutes to form protrusions 30. did. The width of the protrusion 30 was 5 μm, the height was 1.5 μm, and the length of the structural unit 30S of the protrusion 30 was as described above. As shown in (E), the vertical alignment film JALS684 (manufactured by JSR) was spin-coated under the conditions of 2000 rpm and 30 s, and baked at 180 ° C. for 60 minutes to form the vertical alignment film 20.

  A seal (XN-21F, manufactured by Mitsui Toatsu Chemicals) is formed on one of the substrate 12 and the TFT substrate 14, and 4.5 μm spacers (SP-20045, manufactured by Sekisui Fine Chemical) are sprayed on the other substrate. The substrates were stacked. Finally, an empty panel was manufactured by baking at 135 ° C. for 60 minutes. Rubbing and cleaning are not performed. Next, liquid crystal MJ961213 (manufactured by Merck) having negative dielectric anisotropy was injected into the empty panel by vacuum injection. Finally, the inlet was sealed with a sealing material (30Y @ 228, manufactured by ThreeBond) to produce a liquid crystal panel.

  The liquid crystal panel thus produced was measured for transmittance when 5 V was applied and found to be 25.7%. Moreover, when the response speed when a voltage was applied from 0 V to 5 V was measured, the overshoot was 1.6%.

  In the case of the liquid crystal display device having the linear structure of FIG. 15, the transmittance when 5 V was applied was measured and found to be 26.3%. Moreover, when the response speed when a voltage was applied from 0 V to 5 V was measured, the overshoot was 1.1%. The width of the protrusions was 10 μm, the height was 1.5 μm, the length of the protrusion constituent units was 30 μm, the gap between the protrusion constituent units was 10 μm, and the protrusion gap when the upper and lower substrates were overlapped was 20 μm.

  In the case of the liquid crystal display device having the linear structure of FIG. 17, the transmittance when 5 V was applied was measured and found to be 26.6%. Further, when the response speed when a voltage was applied from 0 V to 5 V was measured, the overshoot was 0.9%. In the case of the liquid crystal display device having the linear structure shown in FIG. 18, the transmittance when 5 V was applied was measured and found to be 26.1%. Moreover, when the response speed when a voltage was applied from 0 V to 5 V was measured, the overshoot was 1.6%. In this case, the width of the protrusion is 10 μm, the height is 1.5 μm, the length of the protrusion constituent unit is 30 μm, the length of the other protrusion constituent unit is 70 μm, the gap between the protrusion constituent units is 10 μm, and the upper and lower substrates are stacked. The gap between the protrusions when combined was set to 20 μm. In addition, a pair of substrates was bonded to each other so that the long protrusion constitutional unit on the upper and lower substrates was in the same position as two short protrusion constitutional units.

  In the case of the liquid crystal display device having the linear structure of FIG. 20, the transmittance when 5 V was applied was measured and found to be 26.0%. Moreover, when the response speed when a voltage was applied from 0 V to 5 V was measured, the overshoot was 1.6%. In this case, the width of the protrusion is 10 μm, the height is 1.5 μm, the length of the protrusion constituent unit is 30 μm, the gap between the protrusion constituent units is 50 μm, the gap between the protrusion constituent units is 10 μm, and the upper and lower substrates are overlapped The gap between the protrusions was set to 20 μm. Further, the protrusions were formed such that the protrusion constitutional unit of the other substrate was in the gap between the protrusion constitutional units of one substrate.

  As Comparative Example 1, the following measurements were performed. A protrusion having no structural unit was formed to produce a liquid crystal panel. The width of the protrusion was 10 μm, the height was 1.5 μm, and the gap between the protrusions when the upper and lower substrates were overlapped was 20 μm. The transmittance when 5 V was applied was measured and found to be 22.8%. Moreover, when the response speed when a voltage was applied from 0 V to 5 V was measured, the overshoot was 7.5%.

  As Comparative Example 2, the following measurements were performed. A liquid crystal panel having protrusions similar to those in FIG. 15 but having a long constituent unit length was manufactured. The width of the protrusions was 10 μm, the height was 1.5 μm, the length of the protrusion constituent units was 300 μm, the gap between the protrusion constituent units was 10 μm, and the protrusion gap when the upper and lower substrates were stacked was 20 μm. The transmittance when 5 V was applied was measured and found to be 23.5%. Moreover, when the response speed when a voltage was applied from 0 V to 5 V was measured, the overshoot was 6.3%.

  As Comparative Example 3, the following measurements were performed. A liquid crystal panel having projections similar to those in FIG. 15 but having a short constituent unit length was produced. The width of the protrusions was 10 μm, the height was 1.5 μm, the length of the protrusion constituent units was 10 μm, the gap between the protrusion constituent units was 10 μm, and the protrusion gap when the upper and lower substrates were overlapped was 20 μm. The transmittance when 5 V was applied was measured and found to be 24.1%. Moreover, when the response speed when a voltage was applied from 0 V to 5 V was measured, the overshoot was 5.9%.

  FIG. 24 is a diagram showing the alignment of the liquid crystal of the liquid crystal display device having a linear structure similar to FIG. FIG. 25 is a diagram showing display characteristics in the configuration of FIG. In FIG. 25, 54 is an area that looks dark.

  In FIG. 24, the liquid crystal molecules located between the protrusions 30 of the upper substrate 12 and the protrusions 32 of the lower substrate 14 are aligned substantially perpendicular to the protrusions 30 and 32. The liquid crystal molecules on the protrusions 30 and 32 are aligned substantially parallel to the protrusions 30 and 32.

  It has been found that the boundary and the number of divisions of the regions with different orientation states on the protrusions 30 and 32 continue to change over several tens of seconds when the voltage is long from several seconds after voltage application. It was found that this was recognized as a change in the transmittance of the liquid crystal panel as the main factor of overshoot.

  The cause is considered as follows. For example, when the protrusions 30 and 32 extend to the left and right as shown in FIG. 24, there are two possible directions of the liquid crystal molecules on the protrusions 30 and 32: right and left. However, if there is no means for restricting which direction it faces, it will fall randomly in either direction immediately after voltage application. Thereafter, the regions with different alignment states on the protrusions 30 and 32 affect each other, but the liquid crystal in these regions has no restriction on the alignment direction, so that the state can be easily changed by being influenced by the surroundings. End up. In this way, it is considered that the liquid crystals in the regions with different alignment states on the protrusions 30 and 32 continue to change for a long time.

  As described above, by configuring the protrusion or slit structure from a plurality of structural units, it is possible to regulate the orientation direction based on the division position of the structural units.

  FIG. 26 is a diagram showing the alignment of liquid crystal in a liquid crystal display device having a linear structure composed of a plurality of structural units. FIG. 27 is a diagram showing display characteristics in the configuration of FIG. In FIG. 27, 54 is an area that looks dark. 26 and 27 show, for example, the characteristics of the liquid crystal molecules of the liquid crystal display device of FIG.

  The protrusions 30 and 32 are divided into regions having different orientation states on the protrusions 30 and 32 with respect to the cut portions 30T and 32T. As a result of observation, no change with time in the liquid crystal was observed in the cut portions 30T and 32T. However, it has been newly found that there are a plurality of regions having different alignment states of the liquid crystal between the cut portions 30T and 32T and the adjacent cut portions (within the protrusion structural units 30S and 32S). Although it was slightly less than before, it was found that the boundary between these regions changed with time and there was room for improvement of overshoot.

  FIG. 28 is a diagram showing the alignment of the liquid crystal of the liquid crystal display device having a linear structure according to the second embodiment of the present invention. FIG. 29 is a diagram showing display characteristics in the configuration of FIG. FIG. 30 is an enlarged view of the boundary characteristics of the first type of orientation and the boundary characteristics of the second type of orientation that appear in FIG.

  In FIG. 28 and FIG. 30, when a means capable of controlling the alignment of the liquid crystal on the protrusions 30 and 32 is considered, it has been found that there are two types of boundaries for the boundaries of a plurality of regions having different alignment states of the liquid crystal. In the first type (I), surrounding liquid crystal molecules face one point. In the second type (II), some of the surrounding liquid crystal molecules face one point, and the other liquid crystal molecules face the opposite from the same point. In FIG. 28, the liquid crystal molecules are shown having a head and a foot, but in the first type (I), the heads of all the liquid crystal molecules face the center or the feet of all the liquid crystal molecules are centered. Facing or doing. In the second type (II), the heads of some liquid crystal molecules face the center and the legs of other liquid crystal molecules face the center.

  In FIG. 28, the protrusions 30 and 32 which are linear structures of each substrate are provided with means 56 for forming a boundary of the first type (I) orientation in which the surrounding liquid crystal molecules face one point, and the surrounding liquid crystal molecules. And a means 58 for forming a boundary of a second type (II) orientation in which a part of the liquid crystal molecules face one point and the remaining liquid crystal molecules face the opposite from the same point. The means 56 for forming the boundary of the first type orientation (I) is provided in the structural units 30S, 32S of the protrusions 30, 32, and the means 58 for forming the boundary of the second type (II) orientation is the protrusion. 30 and 32 are provided at the boundary between the structural units 30S and 32S (that is, the separation units 30T and 32T that separate the structural units 30S and 32S).

  As can be seen from the above description and FIG. 2, the protrusions 30 and 32 can control the alignment of the liquid crystal molecules on the main slope. Similarly, the separation portions 30T and 32T that define the boundaries between the structural units 30S and 32S of the protrusions 30 and 32 also have slopes, and the orientation of liquid crystal molecules can be controlled by the slopes. The inclined surfaces of the separation portions 30T and 32T extend substantially in the lateral direction with respect to the longitudinal direction of the protrusions 30 and 32. The main inclined surfaces of the protrusions 30 and 32 align liquid crystal molecules in a direction perpendicular to the longitudinal direction of the protrusions 30 and 32, whereas the inclined surfaces of the separating portions 30T and 32T cause liquid crystal molecules to protrude into the protrusions 30 and 32. It is orientated substantially parallel to the longitudinal direction. On the other hand, the liquid crystal molecules are aligned in the direction perpendicular to the longitudinal direction of the protrusions 30 and 32 as a whole, and the same effect is obtained in the separating portions 30T and 32T. Therefore, the separation parts 30T and 32T become means 58 for forming the boundary of the second type (II).

  FIGS. 31 and 32 show a specific example of the means 56 for forming the boundary of the first type (I) orientation. FIG. 32 is a cross-sectional view of a cross section passing through the protrusion 30 of the upper substrate 12 and a cross section passing through the protrusion 32 of the lower substrate 14. The means 56 is a dot-like protrusion provided on the protrusions 30 and 32. This means 56 assists the alignment of the liquid crystal in terms of shape or electric field, and allows the alignment of the liquid crystal molecules as described above. Therefore, the alignment region of the liquid crystal on the protrusions 30 and 32 can be divided using the portion as a nucleus. Since the alignment of the liquid crystal is different between the boundary of the first type (I) and the boundary of the second type (II), the effect to be imparted to the protrusions is naturally different.

  The means 56 for forming the boundary of the first type (I) alignment can cause the liquid crystal molecules to fall down on the upper substrate 12 toward the high portion of the protrusion. In this way, the orientation direction of all the domains on the projection can be determined only by alternately arranging the cut portions and the raised portions of the projection. Therefore, it is possible to suppress the change of the liquid crystal domain with time after the voltage application, and the overshoot can be almost completely eliminated.

  In order to form the means 56 protruding on the protrusions 30 and 32, a minute structure was formed in advance before the formation of the protrusions 30 and 32. The structure may be formed after the protrusions 30 and 32 are formed. The size of the structure was 10 μm square and the height was 1 μm. Here, the same material as the protrusion material was used as the material of the structure. In addition, if it is formed on the TFT substrate, there is a method of laminating a wiring metal layer or an insulator layer in the corresponding part, and if it is a CF substrate, the process is increased by laminating a color layer or BM in the corresponding part. And a desired structure can be obtained.

  Photosensitive acrylic material PC-335 (manufactured by JSR) was used as the projection material. The projection width is 10 μm, the projection gap (the distance from the projection end of one substrate to the projection end of the other substrate after bonding both substrates) is 30 μm, and the projection height is 1.5 μm (the portion where the projection height is increased) Is 2.5 μm because it is 1 μm higher in advance). The size of the separating portions 30S and 32S of the protrusions 30 and 32 is 10 μm square, and the distance from the center of the separating portions 30S and 32S to the center of the high portion 56 of the protrusions 30 and 32 is 60 μm (with a height of 1.5 μm). The protrusions are continuously present with a length of 50 μm).

  JALS-204 (manufactured by JSR) was used as the vertical alignment film. A micropearl having a diameter of 3.5 μm (manufactured by Sekisui Fine Chemical) was used as a spacer mixed with the liquid crystal, and MJ95785 (manufactured by Merck) was used as a liquid crystal material.

  33 and 34 are a plan view and a cross-sectional view showing a modification of the linear structure. This example is the same as the previous example except for the following points. The upper and lower substrates 12, 14 have protrusions 30, 32. As means 56 for forming the boundary of the first type of orientation (I) and means 58 for forming the boundary of the second type (II), the protrusion 30, In FIG. 32, high and low protrusion portions were alternately provided. The portions 58 of the protrusions 30 and 32 having a low protrusion height are separation portions 30T and 32T that separate the structural units 30S and 32S. The protrusion height of the lower portion 58 was 1 μm. As a method for lowering the protrusions, in this embodiment, the formed protrusions 30 and 32 were selectively ashed by oxygen plasma irradiation. In addition, if it is formed on a TFT substrate, a desired structure can be obtained without increasing the process by a method of opening a contact hole in the corresponding portion, and if it is a CF substrate, a method of removing the color layer and overcoat layer in the corresponding portion. .

  FIG. 35A is a plan view showing a modification of the linear structure. The upper and lower substrates 12, 14 have protrusions 30, 32. As means 56 for forming the boundary of the first type of orientation (I) and means 58 for forming the boundary of the second type (II), the protrusion 30, 32 wide and narrow portions were alternately provided. The width of the wide portion 56 was 15 μm, and the width of the narrow portion 58 was 5 μm (normal width is 10 μm).

  FIG. 35B is a plan view showing a modification of the linear structure. The upper and lower substrates 12, 14 have protrusions 30, 32. As means 56 for forming the boundary of the first type of orientation (I) and means 58 for forming the boundary of the second type (II), the protrusion 30, The width of 32 was continuously changed, and wide portions and narrow portions were alternately provided.

  FIG. 36 is a plan view showing a modification of the linear structure. The lower substrate 14 has a slit 46, and the width of the slit 46 is continuously increased as means 56 for forming the boundary of the first type of orientation (I) and means 58 for forming the boundary of the second type (II). The wide and narrow portions were alternately provided.

  FIG. 37 is a plan view showing a modification of the linear structure. The upper substrate 12 is a CF substrate, and the lower substrate 14 is a TFT substrate. The panel size was 15 type, and the number of pixels was 1024 × 768 (XGA). FIG. 37 shows one pixel unit of the panel. The height of the central portion 32P of the protrusion 32 of the TFT substrate 14 was lowered, and the height of the central portion 30P of the protrusion 30 of the CF substrate 12 was increased. In consideration of the influence of the edge of the pixel electrode 22, a desired alignment state can be realized.

  In applying the present invention to a liquid crystal panel using a TFT substrate, it is necessary to sufficiently consider the influence of the electric field direction due to the edge of the pixel electrode 22 of the TFT substrate.

  FIG. 38 is a cross-sectional view of a portion near the edge of the pixel electrode 22 of the liquid crystal display device, and FIG. 39 is a diagram showing the alignment of the liquid crystal at the edge of the pixel electrode 22 of FIG. 39A shows a portion of the protrusion 30 of the upper substrate 12, and FIG. 39B shows a portion of the protrusion 32 of the lower substrate 14. As shown in FIGS. 38 and 39, there is an oblique electric field 60 at the edge of the pixel electrode 22, and this oblique electric field 60 causes liquid crystal molecules to be centered in the pixel when the TFT substrate is viewed downward and the counter substrate is viewed upward. It has a role to turn to. This functions as if the edge portion of the pixel electrode 22 is a means 56 for forming the boundary of the first type of orientation (I) with respect to the protrusion 32 of the TFT substrate. This means that it functions as if it were the means 58 for forming the boundary of the second type (II).

  In other words, the boundary closest to the pixel electrode edge on the TFT substrate protrusion 32 always takes the second type of orientation (II), and the boundary closest to the pixel electrode edge on the CF substrate protrusion 30 is always the first. It can be said that the state of type 1 (I) is taken. Therefore, in the configuration of FIG. 37, by defining the alignment direction on the protrusions 30 and 32 in accordance with the regulation direction by the pixel electrode edge, the alignment of all domains on the protrusion can be controlled even in the TFT liquid crystal panel. .

  FIG. 40 is a plan view showing a modification of the linear structure. With respect to the TFT substrate, the protrusion height is lowered as the orientation control means 58 on the protrusion 32 closest to the pixel electrode edge, and the protrusion height is increased as the orientation forming means 56 inside thereof. With respect to the CF substrate, the protrusion height is increased as the orientation control means 56 on the protrusion 30 closest to the pixel edge, and the protrusion height is decreased as the orientation forming means 58 inside thereof.

  In the embodiments described so far, the upper substrate and the lower substrate have the same protrusion shape, but this is not always necessary. For example, the same effect can be obtained with a high protrusion and a low protrusion on the upper substrate, and a wide protrusion and a narrow protrusion on the lower substrate. Further, it is not necessary to arrange only two types of shape changes alternately on the same protrusion.

  For example, it is not necessary to repeat high protrusions-low protrusions-high protrusions-low protrusions. High protrusions-low protrusions-wide protrusions-narrow protrusions-high protrusions-low protrusions may be used as long as the shape changes satisfying the boundary between the first and second types (I) and (II) are arranged alternately. . Table 1 shows such a shape change in the case of protrusions and slits.

Table 1
First type (I) Second type (II)
Boundary forming means 56 Boundary forming means 58
Cutting the protrusion Increasing the height of the protrusion Decreasing the height of the protrusion Increasing the width of the protrusion Decreasing the width of the protrusion Pulling out the electrode under the protrusion Cutting the slit Increasing the height of the slit Reduce the height (protrude) (open a hole)
Increase slit width Reduce slit width

  FIG. 41 is a diagram showing the alignment of the liquid crystal in the linear structure of FIG. In this case, the orientation in the display domain is a bend orientation.

  FIG. 42 is a view showing a modification of the linear structure shown in FIG. In this case, the orientation in the display domain is a splay orientation. By changing from the configuration of FIG. 41 to the configuration of FIG. 42, the bend alignment can be changed to the splay alignment.

  FIG. 43 is a plan view showing a linear structure according to the third embodiment of the present invention. 44 is a cross-sectional view of the liquid crystal display device passing through the linear structure of FIG. The basic configuration of the liquid crystal display device 10 is the same as the basic configuration of the liquid crystal display device 10 of the embodiment shown in FIGS. That is, the liquid crystal display device 10 has the protrusions 30 and 32 as linear structures that control the alignment of the liquid crystal. The protrusions 30 and 32 are arranged in parallel to each other and shifted from each other when viewed from the normal line of the substrate. 44 is a cross-sectional view through the protrusion 32 of the lower substrate 14, and the protrusion 30 of the upper substrate 12 is not shown in FIG.

  In this embodiment, the upper substrate 12 and the lower substrate 14 have means 62 and 64 for forming a boundary of alignment of liquid crystal molecules at a fixed position when a voltage is applied to the opposite substrates. In FIG. 44, the upper substrate 12 has means 62 composed of dot-like projections 62a in the same cross section as the projections 32 of the lower substrate. Similarly, as shown in FIG. 43, the lower substrate 14 has means 64 composed of dot-like protrusions 64 a in the same cross section as the protrusions 30 of the upper substrate 12.

  FIG. 45 is a diagram showing the alignment of the liquid crystal in the vicinity of the linear structure shown in FIG. FIG. 46 is a diagram showing the alignment of the liquid crystal in the vicinity of the linear structure according to the first embodiment.

  In the first embodiment, each of the protrusions 30 and 32 is formed from a plurality of structural units 30S and 32S. The means 62, 64 for forming the alignment boundary of the liquid crystal molecules in this embodiment at a fixed position has the same operation as that in the first embodiment, in which the protrusions 30, 32 are formed from a plurality of structural units 30S, 32S. It is what you have. Therefore, as can be seen by comparing FIG. 45 and FIG. 46, the formation positions of the means 62 and 64 along the protrusions 30 and 32 are the cut portions or boundaries of the plurality of structural units 30S and 32S of the first embodiment. The position is the same.

  As shown in FIG. 44 and FIG. 45, the means 62 is configured such that the liquid crystal molecules on the protrusion 32 are tilted toward the protrusion 62 a direction of the means 62. Similarly, the means 64 is configured such that the liquid crystal molecules on the protrusion 30 are tilted in the direction of the protrusion 64 a of the means 64. Therefore, these means 62 and 64 have the same meaning as that when the protrusions 30 and 32 are formed from a plurality of structural units 30S and 32S, the liquid crystal molecules are inclined toward the cut portion or the boundary 32T. I understand that.

  In the case of the configuration of FIG. 46, it is desirable that the liquid crystal molecules beside the protrusions 32 be perpendicular to the protrusions 32, but the liquid crystal molecules beside the cut or boundary 32 T Therefore, it does not necessarily face completely perpendicular to the protrusion 32. 44 and 45, since the protrusions 32 are not discontinuous, all the liquid crystal molecules beside the protrusions 32 are perpendicular to the protrusions 32. Therefore, both the alignment of the liquid crystal in the display area and the area on the protrusion can be controlled without lowering the luminance.

  Photosensitive acrylic material PC-335 (manufactured by JSR) was used for the dot-like protrusions 62a and 64a. The dot-like protrusions 62a and 64a had a width of 5 μm and a height of 1.5 μm. The linear protrusions 30 and 32 had a width of 10 μm and a height of 1.5 μm.

  FIG. 47 is a view showing a modification of the linear structure and the control means for the orientation of the boundary. (A) is a sectional view, (B) is a schematic perspective view, and (C) is a plan view. In this embodiment, the means 62 for forming the alignment boundary of the liquid crystal molecules at a fixed position is a dot-like slit structure 62b of the counter substrate. This means 62 is formed by providing a slit in the electrode 18 and forming the vertical alignment film 20 on the electrode 18. The size of the slit was 14 × 4 μm and 10 × 4 μm, and the display brightness was improved. The width of the slit can be further reduced.

  FIG. 48 is a diagram showing a modification of the linear structure and the control means for the orientation of the boundary. In this embodiment, the means 62 for forming the alignment boundary of the liquid crystal molecules at a fixed position is a dot-like protrusion 62a. The protrusion 62 a is formed by providing a slit or hole in the electrode 18, forming a protrusion 66 on the substrate in the slit or hole, and then forming the vertical alignment film 20 on the electrode 18. The protrusion 62a had a width of 3 μm, a length of 8 μm, and a height of 1.5 μm. The protrusion 66 was made of acrylic resin. In addition, as a protrusion forming means, a material of a bus line or an insulating layer may be selectively used if it is a TFT substrate. In the case of a CR substrate, materials for a color filter layer, a black mask layer, and an overcoat layer may be selectively used.

  Further, instead of the projection 66a, a slit 62 or a hole may be provided in the substrate to form a recess, and the means 62 for forming the alignment boundary of the liquid crystal molecules at a fixed position may have a slit structure. In this case, if it is a TFT substrate, a contact hole may be selectively formed to form a recess. In the case of a CR substrate, depressions may be selectively provided in the color filter layer, black mask layer, and overcoat layer.

  FIG. 49 is a diagram showing a modification of the linear structure and the control means for the orientation of the boundary. In this embodiment, the means 62 for forming the alignment boundary of the liquid crystal molecules at a fixed position is a dot-like protrusion 62a. This means 62 is formed by providing projections 68 on the substrate 12, forming the electrodes 18, and forming the vertical alignment film 20. The substrate 12 may be provided with a recess, and the means 62 may have a slit structure.

  FIG. 50 is a diagram showing a modification of the linear structure and the control means for the orientation of the boundary. 43 to 49, the linear structure is composed of the protrusions 30 and 32, but the linear structure may be composed of the slit structures 44 and 46 (see FIGS. 7 and 8). ). In this embodiment, the linear structure is composed of the slit structure 46, and the means 62 for forming the alignment boundary of the liquid crystal molecules at a fixed position is a dot-like protrusion 62a. This means 62 is formed by providing projections 68 on the substrate 12, forming the electrodes 18, and forming the vertical alignment film 20.

  FIG. 51 is a diagram showing a modification of the linear structure and the control means for the orientation of the boundary. In this example, the protrusions 30 and 32 as the linear structures are bent and provided. As described above, it is necessary to consider the influence of the oblique electric field from the edge of the pixel electrode 22 of the TFT substrate to the counter electrode 18. In this case, of the wedge-shaped disclinations formed on the protrusions 32 of the TFT substrate, the disclination closest to the edge of the pixel electrode has an intensity s = -1, which is the second type (II in FIG. ). Of the wedge-shaped disclinations formed on the protrusions of the CF substrate, the disclination closest to the edge of the pixel electrode has an intensity s = + 1, which corresponds to the boundary of the first type (I) in FIG. To do. Therefore, in an actual application to a liquid crystal panel, all domains in a pixel can be stably controlled by determining the alignment direction on the protrusions 30 and 32 in accordance with the state of disclination formation by the edge of the pixel electrode 22. can do.

  In this embodiment, means 64 for selectively projecting the electrode located at the opposite portion of the protrusion 30 of the CF substrate to form the alignment boundary of the liquid crystal molecules at a fixed position. Further, a protrusion 62 is selectively provided on the portion of the TFT substrate 12 opposite to the protrusion 32 to form a liquid crystal molecule alignment boundary at a certain position. Further, when a plurality of wedge-shaped disclinations are provided on one projection in a pixel, an orientation control means may be provided so that s = −1 and s = + 1 disclinations are alternately arranged. In this embodiment, as shown in FIG. 53, the means 62 in which the electrode 22 protrudes on the protrusion 68 and the means 62 in which the protrusion 69 protrudes on the electrode 22 are alternately arranged.

  54 and 55 are diagrams showing a modification of the linear structure and the control means for the orientation of the boundary. In this embodiment, the means 62 for forming the alignment boundary of liquid crystal molecules at a fixed position is formed as a slit 71 of a long extending protrusion 70 provided on the upper substrate 12 so as to face the protrusion 32 of the lower substrate. . The protrusion 70 is provided on the electrode 18 and is narrower than the width of the protrusion 32.

  56 and 57 are diagrams showing a modification of the linear structure and the boundary orientation control means. In this embodiment, the means 62 for forming the alignment boundary of the liquid crystal molecules at a fixed position includes the slits 71 of the long protrusions 70 provided on the upper substrate 12 facing the protrusions 32 of the lower substrate, and the electrodes 18. The slit 72 is formed. The protrusion 70 is provided on the electrode 18 and is narrower than the width of the protrusion 32.

  135 to 157 show the disclination of S = + 1 and S = −1 when a linear alignment control structure is provided on one substrate and a substructure is provided at a position opposite to the other substrate. The example of the substructure which forms is shown collectively. The linear alignment control structure of one substrate may be formed of a protrusion or a slit.

  Means for realizing S = −1 is, for example, as shown in FIGS. 135 to 147. Dots (FIG. 135), dot-like electrode removal (FIG. 136), dents (FIG. 137), dot-like thin projections, electrode removal partially below the projection (FIG. 138), Partially thick part on thin protrusion (FIG. 139), Partially high part on thin linear protrusion (FIG. 140), Partially protruding part on thin linear slit (FIG. 141), Thin electrode on linear line (FIG. 142), a thin part of a thin electrode (FIG. 143), a low part of a thin electrode (FIG. 144), a linear shape A portion that is partially low in the recess of the thin electrode (FIG. 145) and a portion that is partially thick in the recess of the thin electrode (FIG. 146).

  Means for realizing S = + 1 is as shown in FIGS. 147 to 157, for example. The electrode protrudes in the form of dots (FIG. 147), partially cut into thin linear protrusions (FIG. 148), partially thin into thin linear protrusions (FIG. 149), partially into thin linear protrusions 150 (part 150), partly connecting thin slits in a line (FIG. 151), part thin in a line thin slit (FIG. 152), part lower in a line thin slit (FIG. 153), a partially thick part in the protrusion of the linear thin electrode (FIG. 154), a partially high part in the protrusion of the linear thin electrode (FIG. 155), a part in the recess of the linear thin electrode High part (FIG. 156) and partly thin part (FIG. 157) in the dent of the thin electrode.

  58 is a plan view showing a linear structure according to a fourth embodiment of the present invention, and FIG. 59 is a cross-sectional view of the liquid crystal display device taken along line 59-59 in FIG. The basic configuration of the liquid crystal display device 10 is the same as the basic configuration of the liquid crystal display device 10 of the embodiment shown in FIGS. In this embodiment, each projection (linear structure) 30, 32 is formed of a plurality of structural units 30a, 32a, and the linear structure of one substrate is viewed from the normal direction of one substrate. The structural unit and the structural unit of the linear structure of the other substrate are alternately arranged on one line.

  For example, in FIG. 58, regarding the structural unit of the protrusion on the upper line (line 59-59), the structural unit 30a of the protrusion 30 of the upper substrate 12 and the structural unit 32a of the protrusion 32 of the lower substrate 14 are Alternatingly arranged on this line. FIG. 59 shows these structural units 30a and 32a. As shown in FIG. 59, the liquid crystal molecules on this line are continuously tilted in the direction parallel to the line, and the liquid crystal molecules on the protrusion are random as described with reference to FIG. The problem of falling in the direction can be solved.

  58, the structural unit 32a of the protrusion 32 of the lower substrate 14 on the upper line, the structural unit 30a of the protrusion 30 of the upper substrate 12 on the middle line, and the lower unit. The positional relationship of the protrusion 32 of the lower substrate 14 with the structural unit 32a is the same as the arrangement of FIGS. 3 and 4, and this relationship is such that these protrusions are in a plane oblique to the substrate surface as shown in FIG. It is the same as facing each other. The same applies to FIG. Therefore, the operation of the liquid crystal display device of this example is basically the same as that of the first embodiment. In particular, with this configuration, it is possible to improve the response speed in halftone. The configuration of FIG. 58 is similar to the configuration of FIG.

  60 and 61 are diagrams showing modifications of the linear structure. In this example, the upper substrate 12 uses a protrusion 30 as a linear structure, while the lower substrate 14 uses a slit structure 46 as a linear structure. When the slit structure 46 is divided into structural units 46a, it is as shown in FIG. In this case, electrical connection of individual pixel electrodes separated by the slits can be realized with a wider width, and there is an advantage that a design margin is widened. In addition, there is an advantage that there is no worry about disconnection of the connecting portion between the slits of the pixel electrode 22 and an increase in resistance.

  In this example, each linear structure has a plurality of structural units in one pixel, and the linear structures are arranged approximately symmetrically in one pixel. This feature is the same when, for example, this feature is applied to a bent linear structure as shown in FIG.

  FIG. 62 is a diagram showing a modification of the linear structure. In this example, as shown in FIG. 58, the structural units 30a and 32a of the protrusions 30 and 32 are alternately arranged, and at least one of the structural units 30a and 32a of the protrusions 30 and 32 of each substrate is the periphery. Means 74 for forming alignment boundaries so that the liquid crystal molecules of the liquid crystal molecules face one point. The means 74 for forming the boundary of this orientation is similar to the means 56 for forming the boundary of the first type of orientation (I) of FIG. The first type of orientation (I) forms the singular point of the orientation vector corresponding to s = 1. In this case, it is possible to control the orientation vector of the micro domain on the protrusion, and as a result, stable control of the display domain is realized, and the response speed in the halftone is improved.

  This means 74 can be similar to that of the second embodiment described above.

  FIG. 63 shows a specific example of the means 74 for forming the alignment boundary. In FIG. 63, this means 74 is to increase the width of the structural units 30a, 32a of the protrusions 30, 32.

  As shown in FIG. 64, this means 74 can also be achieved by increasing the height of the structural units 30a, 32a of the protrusions 30, 32.

  In the part where the width of the structural units 30a and 32a of the protrusion is partially increased or the height is increased, the liquid crystal director spreads around that part, so that the singular point of s = 1. In addition, due to the oblique electric field of the pixel electrode, the liquid crystal director from the edge of the pixel electrode toward the center of the pixel is in the direction of rising to the center on all the protrusions when the common substrate is arranged in front, It is possible to form minute domains that are continuously connected at the boundary without difficulty.

  FIG. 65 shows a specific example of the means 74 for forming the alignment boundary. In FIG. 65, the linear structure is a combination of the protrusion 32 and the slit structure 44, and this means 74 increases the width or height of the structural unit 32a of the protrusion 32 and the slit structure. This is achieved by increasing the width of 44 or increasing the depth.

  Table 2 shows the result of comparing the response speed with the structure of the first embodiment. (Slit width 10 μm, protrusion width 10 μm, spacing 20 μm.)

Table 2
1st Example 4th Example Driving Conditions T _ON + T _OFF -25 ms -25 ms 0-5V
T _ON + T _OFF -50ms -40ms 0-3V

  Thus, the smooth movement of the micro domains on the protrusion has an improvement effect on the response speed. It was confirmed that the response in halftone was improved by stable orientation. In addition, since the width of the electrical connection portion of the slit can be increased, there is no need to worry about disconnection or the like, resulting in a merit.

  In the present embodiment, the description has been made taking the two-part division as an example, but the same applies to the bent type. Also, some embodiments can be combined.

  FIG. 66 is a plan view showing a linear structure according to the fifth embodiment of the present invention. The basic configuration of the liquid crystal display device 10 is the same as the basic configuration of the liquid crystal display device 10 according to the embodiment shown in FIGS. In the embodiment of FIG. 5, the protrusions (linear structures) 30 and 32 extend parallel to each other and bend. According to this configuration, there are regions of liquid crystal molecules 16C, 16D, 16E, and 16F aligned in four directions in one pixel, and alignment division with excellent viewing angle characteristics is achieved.

  The two straight portions forming the bent portions of the protrusions 30 and 32 form 90 degrees. The polarizing plates 26 and 28 are arranged so as to form 45 degrees with respect to the linear portions of the bent portions of the protrusions 30 and 32 as indicated by 48 in the polarization axis. FIG. 66 shows only some liquid crystal molecules, but there are regions of liquid crystal molecules 16C, 16D, 16E, and 16F aligned in four directions in one pixel (see FIG. 5).

  In this embodiment, additional protrusions 76 and 78 as additional linear structures are provided on the obtuse angle side of the bent portion of the substrate on which the protrusions 30 and 32 are provided. That is, the additional protrusion 76 is continuously provided from the protrusion 30 on the obtuse angle side of the protrusion 30 of the upper substrate 12. The additional protrusion 76 extends on an obtuse angle side of the protrusion 30 of the upper substrate 12 on a bisector of this obtuse angle. On the other hand, the additional protrusion 78 is continuously provided from the protrusion 32 on the obtuse angle side of the protrusion 32 of the lower substrate 14. The additional protrusion 78 extends on the bisector of this obtuse angle on the obtuse angle side of the protrusion 32 of the lower substrate 14. This increases the brightness and improves the responsiveness.

  FIG. 67 shows protrusions 30 and 32 similar to FIG. FIG. 67 shows the alignment of the liquid crystal molecules with respect to the protrusions 30 and 32 in more detail. There are regions of liquid crystal molecules 16C, 16D, 16E, and 16F aligned in four directions in one pixel. Further, there is a region of liquid crystal molecules 16G on the obtuse angle side of the bent portion of the protrusion 30, and liquid crystal molecules 16H are on the obtuse angle side of the bent portion of the protrusion 32. When a voltage is applied, the liquid crystal molecules should tilt vertically with respect to the protrusions 30 and 32. However, the liquid crystal molecules are not controlled by the protrusions 30 and 32 at the bent portions of the protrusions 30 and 32, and 2 of the bent portions. Since the liquid crystal molecules 16D-16F and 16C-16E located in the two linear portions are aligned in a fan shape, the liquid crystal molecules 16G and 16H are aligned in parallel on the bisector of the obtuse angle of the bent portions of the protrusions 30 and 32. Will come to do. The alignment directions of the liquid crystal molecules 16G and 16H are parallel or orthogonal to the polarization axis indicated by 48, and when a white display is formed by applying a voltage, the regions of the liquid crystal molecules 16G and 16H become dark.

  FIG. 68 shows a screen when the white display of the liquid crystal display device having the linear structure of FIG. 67 is seen, and the regions G and H of the liquid crystal molecules 16G and 16H are actually dark. In addition, the edge region I of the pixel electrode 22 is also darkened. This will be described later.

  In FIG. 66, since the additional protrusions 76 and 78 are provided on the obtuse angle side of the bent portion of the substrate on which the protrusions 30 and 32 are provided, the alignment of the liquid crystal molecules 16G and 16H in question is corrected and located on both sides thereof. It becomes close to the alignment of the liquid crystal molecules 16D-16F and 16C-16E. Therefore, the areas G and H shown in FIG. 68 are not darkened, and the luminance is improved.

  The additional protrusions 76, 78 may have the same width as the original protrusions 30, 32. However, it is desirable that the width of the additional protrusions 76 and 78 is smaller than the width of the original protrusions 30 and 32. This is because if the alignment regulating force of the additional protrusions 76 and 78 is strong, liquid crystal molecules in the vicinity thereof are aligned so as to be orthogonal to the additional protrusions 76 and 78. When the alignment restricting force of the additional protrusions 76 and 78 is weak, the liquid crystal molecules in the vicinity thereof do not reach the position orthogonal to the additional protrusions 76 and 78, and the liquid crystal molecules 16D-16F and 16C-16E located on both sides thereof. It becomes close to the orientation of. For example, when the width of the original protrusions 30 and 32 is 10 μm, the width of the additional protrusions 76 and 78 may be about 5 μm.

  In this way, by newly forming the additional protrusions 76 and 78 on the protrusions 30 and 32, it is possible to clearly determine how the liquid crystal molecules of the bent portion are tilted, so that the brightness and responsiveness can be improved. it can.

  In this example, the glass substrates 12 and 14 used NA-35 and 0.7 mm thickness. ITO was used for the pixel electrode 22 and the common electrode 18. On the pixel electrode 22 side, TFTs, bus lines and the like for driving the liquid crystal are arranged, and a color filter is provided on the counter electrode 18 side. Photosensitive acrylic material PC-335 (manufactured by JSR) was used as the projection material. The protrusion width was 10 μm for both substrates, and the protrusion gap (distance from the protrusion end of one substrate to the protrusion end of the other substrate after bonding both substrates) was 30 μm. The protrusion height was 1.5 μm. As the vertical alignment films 20 and 24, JALS-204 (manufactured by JSR) was used. As the liquid crystal material, MJ95785 (manufactured by Merck) was used. As the spacer, a microbar having a diameter of 3.5 μm (manufactured by Sekisui Fine Chemical) was used.

  FIG. 69 shows a modification of the linear structure. In this example, the additional protrusions 76 x and 78 x are provided on the acute angle side of the bent portions of the protrusions 30 and 32. In this case, the alignment direction of the liquid crystal molecules by the protrusions 30 and 32 is not smoothly continuous with the alignment direction of the liquid crystal molecules by the additional protrusions 76x and 78x, and the liquid crystal molecules in the vicinity of the bent portions of the protrusions 30 and 32 are not polarized. It is directed in a direction perpendicular or perpendicular to the direction, and the effect of improvement is low. Therefore, as shown in FIG. 66, it has been found that the additional protrusions 76 x and 78 x are preferably provided on the obtuse angle side of the bent portions of the protrusions 30 and 32.

  So far, the additional protrusions 76 and 78 have been described from the same substrate on which the protrusions 30 and 32 are provided. The additional projections 76 and 78 are as follows when viewed from the substrate opposite to the projections 30 and 32 provided. For example, in FIG. 66, the additional protrusion 76 is provided on the acute angle side of the bent portion of the protrusion 32 of the substrate 14 facing the substrate 12 on which the protrusion 30 is provided (Claim 34). Similarly, the additional protrusion 78 is provided on the acute angle side of the bent portion of the protrusion 30 of the substrate 12 facing the substrate 14 on which the protrusion 32 is provided.

  FIG. 70 shows a modification of the linear structure. In this example, similar to the example of FIG. 66, the additional protrusions 76 x and 78 x are provided on the obtuse angle side of the bent portions of the protrusions 30 and 32. The additional protrusions 76x and 78x in this example extend longer than the protrusions 76x and 78x in FIG. The tips of the additional protrusions 76x and 78x extend to a position where they overlap the bent portions of the opposing protrusions 32 and 30. The additional protrusions 76x and 78x may be extended in this manner, but it is not preferable that the protrusions 76x and 78x are extended beyond the position where the tips overlap the bent portions of the opposing protrusions 32 and 30.

  Further, in this example, the upper substrate 12 and the lower substrate on which the projections 32 and 30 and the additional projections 76x and 78x are formed are bonded to each other with a peripheral seal to form an empty panel. Injected. In this example, the protrusion height was 1.75 μm, and the cell thickness of 3.5 μm could be obtained by the protrusions of both substrates being in partial contact. The spacer was not used, and the cell thickness was maintained by the partial contact of the protrusions of both substrates. In this configuration, since there is no spacer, the alignment abnormality due to the spacer is eliminated.

  As described above, the linear structure for controlling the orientation is constituted by the protrusions 30 and 32 or the slit structures 44 and 46. Accordingly, when the slit structures 44 and 46 are employed as a linear structure, an additional slit structure having a structure similar to the slit structures 44 and 46 is provided instead of the additional protrusions 76x and 78x. Further, the linear structure for controlling the orientation may have a structure in which a protrusion is provided on the slit from which the electrode is removed.

  FIG. 71 shows a modification of the linear structure. As a linear structure for controlling the orientation, a protrusion 30 of the upper substrate 12 and a slit structure 46 of the lower substrate 14 are provided. As described above, the slit structure 46 is configured by forming a slit in the pixel electrode 22 of the lower substrate 14. An additional protrusion 76 is provided in the same manner as the additional protrusion 76 of FIG. 66, and an additional slit structure 78y is provided on the obtuse angle side of the bent portion of the slit structure 46 instead of the additional protrusion 78 of FIG. The additional slit structure 78y is not continuous with the bent portion of the slit structure 46 because the slit structure 46 is configured as a slit in the pixel electrode 22 and thus there is a discontinuous portion in the slit. It can be expressed that the additional slit structure 78y is provided on the acute angle side of the protrusion 30 of the opposing substrate.

  FIG. 72 shows a modification of the linear structure. In this example, additional protrusions 76 and 78 are provided as in the case of FIG. Further, the edge protrusion 80 is provided at a position overlapping with at least a part of the edge of the pixel electrode 22. In this case, the protrusions 30 and 32 are neither arranged parallel nor orthogonal to the edge of the pixel electrode 22. The edge protrusion 80 is provided at a position corresponding to the region I in FIG. As shown in FIG. 67, the liquid crystal molecules are aligned at the edge of the pixel electrode 22 so as to tilt toward the center of the pixel by the action of an oblique electric field. 68, the projection 30 on the upper substrate (counter substrate) 12 and the edge of the pixel electrode 22 form an obtuse angle. Alternatively, the protrusion 32 on the pixel electrode 22 and the edge of the pixel electrode 22 form an acute angle.

  In such a region, since the alignment of the liquid crystal molecules is significantly different from the alignment of the liquid crystal molecules located inward from the edge (see FIG. 67), the display becomes dark as shown in FIG. As shown in FIG. 72, by providing the edge protrusion 80, the alignment of the liquid crystal molecules at the edge of the pixel electrode 22 becomes close to the alignment of the liquid crystal molecules at the inner position of the edge, and the display becomes dark. Is prevented. In FIG. 72, a corner protrusion 82 is also provided.

  FIG. 73 shows a modification of the linear structure. This example is the same as the case of FIG. 72 except that there is no corner projection 82. 72 and 73, the newly provided protrusion is extended to the protrusion on the pixel electrode. The height of the protrusion was 1.75 μm, and the spacer was not sprayed. A cell thickness of 3.5 μm could be obtained by partial contact of the protrusions of both substrates.

FIG. 74 shows a modification of the linear structure. In this example, the protrusion 30 has an additional protrusion 76, the slit structure 46 has an additional slit structure 78y, and the protrusion 30 and the slit structure 46 have a plurality of structural units (30S, 46S) as in the example of FIG. ). Therefore, in this case, the effect of using a linear structure as a plurality of structural units and the effect of providing an additional linear structure are obtained.
FIG. 75 is a diagram showing the relationship between the linear structure of the liquid crystal display device according to the sixth embodiment of the present invention and the polarizing plate. FIG. 76 is a diagram showing the brightness of display in the configuration of FIG.

  The liquid crystal display device shown in FIG. 75 basically includes the same configuration as the liquid crystal display device shown in FIGS. That is, the liquid crystal display device includes a pair of substrates 12, 14, a liquid crystal 16 having a negative dielectric anisotropy inserted between the pair of substrates 12, 14, and a pair for controlling the alignment of the liquid crystal 16. Linear structures (for example, protrusions 30 and 32, slits 44 and 46) provided on each of the substrates 12 and 14, and polarizing plates 26 and 28 disposed outside the pair of substrates 12 and 14, respectively. Is provided. The pair of substrates 12 and 14 have electrodes 18 and 22 and vertical alignment films 20 and 24, respectively.

  In FIG. 75, the linear structures for controlling the alignment of the liquid crystal are protrusions 30 and 32 similar to those shown in FIG. The arrangement of the polarizing plates 26 and 28 is indicated by 48. The polarizing plates 26 and 28 have absorption axes 26a and 28a, and these absorption axes 26a and 28a are orthogonal to each other. The absorption axis 26a of one polarizing plate 26 (and therefore the absorption axis 28a of the other polarizing plate 28) is arranged at a predetermined angle (a) from the direction rotated 45 degrees with respect to the direction in which the protrusions 30 and 32 extend. ing. In other words, in FIG. 75, the absorption axis 26a of the polarizing plate 26 is at an angle of (45 ° ± a) with respect to a straight line (indicated by a broken line) orthogonal to the protrusions 30 and 32, and thus the protrusion 30 and It is arranged at an angle of (45 ° ± a) with respect to 32 extending directions.

  FIG. 75 shows the behavior of liquid crystal molecules on a linear structure (protrusions 30 and 32) for controlling the alignment of the liquid crystal. In a liquid crystal display device having a linear structure (projections 30, 32, slits 44, 46) for controlling the alignment of the liquid crystal, as described with reference to FIGS. A shoot occurs. One of the causes of this overshoot is that when the polarizing plates 26 and 28 are arranged at 45 ° with respect to the linear structure, the liquid crystal molecules after voltage application are completely in the linear structure. This is because the brightness at the time of white display decreases because the image does not become vertical. This embodiment solves this problem.

  In FIG. 75, when a voltage is applied, the liquid crystal molecules located between the protrusions 30 and 32 are tilted so as to be perpendicular to the protrusions 30 and 32. The liquid crystal molecules on the protrusions 30 and 32 are inclined toward either the right or the left in parallel with the protrusions 30 and 32. Therefore, the liquid crystal molecules located between the protrusions 30 and 32 are not completely perpendicular to the protrusions 30 and 32 and are somewhat oblique to the protrusions 30 and 32. In FIG. 75, the left region L and the right region R are shown separately for the sake of explanation, and the liquid crystal molecules located in the left region L are at an angle a with respect to the line perpendicular to the protrusions 30 and 32. , The liquid crystal molecules in the right region R rotate counterclockwise (the director of the liquid crystal in the left region L is at angle a).

  In this embodiment, polarizing plates 26 and 28 are arranged in accordance with the alignment of the liquid crystal molecules located in the left region L. The absorption axis 26 a of the polarizing plate 26 is disposed at 45 ° with respect to the liquid crystal director located in the left region L. Therefore, as shown in FIG. 76 (A), in the left region L, the brightest display can be realized during white display.

  On the other hand, in the right region R, the condition realized in the left region L is not realized, and as shown in FIG. 76B, the brightest display cannot be realized during white display. However, as shown in FIG. 76 (C), in the entire display (L + R) including the bright left region L and the right region R once brightened and then darkened, a bright display can be realized during white display. Overshoot can be improved considerably.

  FIG. 77 shows the relationship between the angle (a) of the director of the liquid crystal in each minute region and the frequency in the liquid crystal display device having the linear structure (for example, the protrusions 30 and 32) for controlling the alignment of the liquid crystal. FIG. From this result, it can be seen that the director of the liquid crystal is inclined within a range of approximately 20 ° or less. Therefore, the predetermined angle (a) shifted from the direction in which the absorption axis 26a of the polarizing plate 26 is rotated 45 degrees with respect to the direction in which the protrusions 30 and 32 extend may be 20 ° or less.

  In this case, when the crossing angle between the orientation of the absorption axis 26a of the polarizing plate 26 and the linear structure (for example, the protrusions 30 and 32) is b, the crossing angle b is 25 ° <b <45 ° or 45 °. <B <65 °. However, there is a positional relationship error of about 2 ° between the polarizing plates 26 and 28 and the substrates 12 and 14, and taking this into account, the intersection angle b is 25 ° <b <43 ° or 47 °. <B <65 ° is preferable.

  In FIG. 77, more specifically, the frequency of liquid crystal directors in the range of 2 ° and 13 ° is high. Accordingly, the predetermined angle a is preferably in the range of 2 ° and 13 °. In this case, the intersection angle b may be in the range of 32 ° <b <43 ° or 47 ° <b <58 °.

  78 and 79 are diagrams showing modifications of the embodiment of FIG. 78 is a diagram showing the relationship between the linear structure of the liquid crystal display device and the polarizing plate, and FIG. 79 is a cross-sectional view of the liquid crystal display device of FIG. The upper substrate 12 has a protrusion 30, and the lower substrate 14 has a protrusion 32. The protrusions 30 and 32 have right-angled bent portions. In this case, the absorption axis 26 a of the polarizing plate 26 is arranged so as to form 55 ° with respect to the linear portion of the protrusion 30. The absorption axes 26a and 28a of the two polarizing plates 26 and 28 are orthogonal to each other.

  80 and 81 are diagrams showing a modification of the embodiment of FIG. 80 is a diagram showing the relationship between the linear structure of the liquid crystal display device and the polarizing plate, and FIG. 81 is a cross-sectional view of the liquid crystal display device of FIG. The upper substrate 12 has a protrusion 30, and the lower substrate 14 has a slit 46. The protrusion 30 and the slit 46 have a right-angled bent portion. In this case, the absorption axis 26a of the polarizing plate 26 is arranged so as to form 55 ° with respect to the linear portion of the protrusion 30 (or the slit 46). The absorption axes 26a and 28a of the two polarizing plates 26 and 28 are orthogonal to each other.

  FIG. 82 is a diagram showing a linear structure of a liquid crystal display device according to a seventh embodiment of the present invention. 83 is a cross-sectional view of the liquid crystal display device of FIG.

  The liquid crystal display device shown in FIGS. 82 and 83 includes a pair of substrates 12 and 14, a liquid crystal 16 having a negative dielectric anisotropy inserted between the pair of substrates 12 and 14, and the alignment of the liquid crystal 16. Are arranged on the outside of the pair of substrates 12 and 14 and the linear structures (for example, the protrusions 30 and 32 and the slits 44 and 46) provided on each of the pair of substrates 12 and 14, respectively. Polarizing plates 26 and 28 are provided. The pair of substrates 12 and 14 have electrodes 18 and 22 and vertical alignment films 20 and 24, respectively.

  The lower substrate 14 is a TFT substrate, and the electrode 22 is a pixel electrode. The lower substrate 14 has a TFT 40 connected to the pixel electrode 22. The TFT 40 is connected to the gate bus line and the drain bus line (FIG. 3). A light shielding area 84 is provided to cover the TFT 40 and the area in the vicinity thereof. The light shielding region 84 prevents the TFT 40 from being directly irradiated with light. Since the TFT 40 is in contact with the pixel electrode 22, the light shielding region 84 is disposed so as to partially overlap the pixel electrode 22.

  The pixel electrode 22 defines a pixel opening. However, in the area occupied by the pixel electrode 22, the portion where the light shielding region 84 overlaps does not become a pixel opening. Accordingly, a portion of the area occupied by the pixel electrode 22 that does not overlap the light shielding region 84 is a non-light shielding region (pixel opening).

  In this example, the linear structure provided on the upper substrate 12 is a protrusion 30, and the linear structure provided on the lower substrate 14 is a slit 46 formed on the electrode 22. The protrusion 30 and the slit 46 are formed in a shape having a bent portion. Examples of combinations of the protrusions 30 and the slits 46 are shown in FIGS. 71 and 74, for example.

  The light shielding region 84 and the linear structures 30 and 46 are linear structures 30 and 46 which are arranged in the non-light shielding region by partially overlapping the light shielding region 84 and a part of the linear structures 30. Are arranged so as to reduce the area.

  As described above, since the protrusion 30 is formed of a transparent dielectric and the slit 46 is formed on the transparent pixel electrode 22, the linear structures 30 and 47 should be regarded as transparent members. Can do. However, when a voltage is applied, the liquid crystal molecules positioned on the linear structures 30 and 47 are oriented differently from the liquid crystal molecules positioned in the gap between the linear structures 30 and 47. When white display is performed by applying a light, the amount of transmitted light decreases on the linear structures 30 and 47 in the pixel opening, and the aperture ratio decreases.

  Therefore, it is preferable to reduce the area of the linear structures 30 and 46 arranged in the non-light-shielding region (in the pixel opening). However, the linear structures 30 and 46 require a predetermined area for controlling the alignment of the liquid crystal. Therefore, when the areas of the linear structures 30 and 46 are constant, a part of the linear structures 30 and 46 is moved to a position overlapping the light shielding region 84, and the linear structures arranged in the non-light shielding region are arranged. If the area of the structures 30 and 46 is reduced, the actual aperture ratio can be increased. Therefore, in FIG. 82, the light shielding region 84 and the linear structures 30 and 46 are designed so that a part of the protrusion 30 overlaps the light shielding region 84.

  FIG. 84 is a diagram showing a more specific example of the linear structures 30 and 46 of FIG. The features of the apparatus of FIG. 84 are the same as those described with reference to FIG. The source electrode of the TFT 40 is connected to the pixel electrode 22 through a contact hole 40h.

  Further, as shown in FIGS. 82 to 84, when the linear structure of the substrate 14 having the TFT 40 is the slit 46, the projection 30 (or the slit 44) of the counter substrate 12 has a light shielding region 84 that covers the TFT 40. It is preferable to overlap. If the slit 46 overlaps the light shielding region 84, it may be inconvenient to make contact between the TFT 40 and the pixel electrode 22.

  FIG. 85 shows a comparative example of the linear structure of FIG. In this example, when the linear structure of the substrate 14 having the TFT 40 is the slit 46, the TFT substrate 14 or the slit 46 is disposed so as to overlap the light shielding region 84 that covers the TFT 40. However, if the slit 46 overlaps the light shielding region 84, the connection between the TFT 40 and the pixel electrode 22 becomes difficult. That is, the slit 46 comes to a position where a contact hole (40h in FIG. 84) should be formed.

  86 is a view showing a modification of the linear structure of FIG. 28, and FIG. 87 is a cross-sectional view showing a liquid crystal display device having the linear structure of FIG. 86 and 87 are diagrams for explaining an example in which the electrode under the third protrusion in the left column of Table 1 described above is removed. The protrusion 32 is formed on the electrode 22 of the substrate 14, but the electrode 22 under the protrusion 32 is formed with a diamond-shaped punch 22 x. In the case of the protrusion 32, the first type (I) boundary forming means 56 can be obtained by removing the electrode 22x. The cutout 22x is not limited to a rhombus shape, but may be another shape, for example, a rectangular shape.

  FIG. 88 is a diagram showing a linear structure of a liquid crystal display device according to an eighth embodiment of the present invention. 89 is a cross-sectional view of a liquid crystal display device having the linear structure of FIG. The embodiment shown in FIGS. 88 and 89 corresponds to an example having features obtained by combining the features of the embodiment of FIG. 28 and the features of the embodiment of FIG. That is, in this embodiment, the first means for forming the alignment boundary of the liquid crystal provided in the linear structure of one substrate and the linear structure extending on the other substrate are extended. And a second means for forming an alignment boundary of the liquid crystal provided at the same position as the first means in the direction.

  The upper substrate 12 has a linear structure 30 made of protrusions, and the lower substrate 14 has a linear structure 32 made of protrusions. FIG. 89 is a cross-sectional view passing through the linear structure 32 formed by the protrusions of the lower substrate 14. The protrusion 32 has a separation portion 32T, whereby a second type (II) boundary forming means 58 is formed on the protrusion 32. Further, the counter substrate 12 is provided with a dot-like protrusion 62a at a position facing the separation portion 32T. As described with reference to FIG. 43, the protrusion 62a of the counter substrate 12 is a means 62 for forming the alignment boundary of the liquid crystal molecules at a fixed position, which is the second type (II) boundary forming means 58. Has the same liquid crystal alignment control action. Therefore, in this example, the two second type (II) boundary forming means 58 and 62 are provided at the same position, and the second type (II) boundary is more reliably formed. . Therefore, the alignment of the liquid crystal molecules becomes more reliable.

  90 and 91 are diagrams showing an example similar to FIGS. 88 and 89. FIG. Also in this example, the protrusion 32 includes the second type (II) boundary forming means 58, and the counter substrate 12 includes means 62 for forming the alignment boundary of the liquid crystal molecules at a fixed position. 90 and 91, the relationship between the size of the separation portion 32T of the protrusion 32 constituting the means 58 and the size of 62a constituting the means 62 is different from that in FIGS. 88 and 89.

  FIG. 92 is a view showing a modification of the linear structure shown in FIG. FIG. 93 is a cross-sectional view showing the linear structure (projection) 32 of FIG. This linear structure (projection) 32 includes first type (I) boundary forming means 56 formed by increasing the height of the projection 32 as shown in FIG. And a second type (II) boundary forming means 58 formed by lowering the height. The counter substrate 12 includes a boundary forming unit 62 at the same position as the units 56 and 58.

  FIG. 94 is a view showing a modification of the linear structure shown in FIG. This linear structure (projection) 32 has a first type (I) boundary forming means 56 formed by increasing the width of the projection 32 as shown in FIG. Second type (II) boundary forming means 58 formed by doing so. The counter substrate 12 may include a boundary forming unit 62 at the same position as the units 56 and 58.

  95 and 96 are diagrams showing an example similar to FIGS. 88 and 89. FIG. Also in this example, the protrusion 32 includes the first type (I) boundary forming means 56 and the second type (II) boundary forming means 58, and the counter substrate 12 has liquid crystal molecules at the same positions as the means 56 and 58. Means 62 are included for forming alignment boundaries at fixed locations. The first type (I) boundary forming means 56 is a separation part of the protrusion 32, and the second type (II) boundary forming means 58 is a heightened part on the protrusion 32.

  FIG. 97 is a view showing a modification of the linear structure shown in FIG. In this example, the linear structure of the lower substrate 14 is formed as a slit 46. The slits 46 are separated by a wall 58a to form a second type (II) boundary forming means 58. At the same time, the wall 58a forms a means 62 for forming a boundary of alignment of liquid crystal molecules at a fixed position with respect to the linear structure (projection) 30 that cooperates as a protruding wall.

  FIG. 98 shows a linear structure similar to FIG. FIG. In this example, the linear structure of the lower substrate 14 is formed as a slit 46, and the slit 46 is separated by a wall 58a. The wall 58a is located at the separation part and the middle part of the components of the separated linear structure (projection) 30 that cooperates, and the first type (I) boundary forming means 58 and the second type (II). ) For forming a boundary 58). At the same time, the wall 58a forms a means 62 for forming a boundary of alignment of liquid crystal molecules at a fixed position with respect to the linear structure (projection) 30 that cooperates as a protruding wall.

  The embodiment described with reference to FIGS. 88 to 98 can be summarized as follows. (A) As the first type (I) boundary forming means 56, the protrusions 30 and 32 are made thicker or higher, the slits 44 and 46 are made thicker or higher, and the opposing substrate boundary forming means 60, As 62, dot-like projections, partially cut projections, partially thinned projections, partially lowered projections, partially connected slits, partially thinned slits, partially lowered slits Is provided. (B) As the second type (II) boundary forming means 58, the protrusions 30 and 32 are cut (set as a plurality of structural units), thinned or lowered, and the slits 44 and 46 are cut and thinned. Alternatively, the counter substrate boundary forming means 60 and 62 may be pointed protrusions, partially thickened protrusions, partially raised protrusions, partially protruding slits, partially thickened slits, dots A shaped electrode recess is provided.

  FIG. 99 is a diagram showing a linear structure of a liquid crystal display device according to the ninth embodiment of the present invention. Also in this case, as in the previous embodiment, the liquid crystal display device includes a pair of substrates 12 and 14 and a liquid crystal 16 having a negative dielectric anisotropy inserted between the pair of substrates 12 and 14. In order to control the alignment of the liquid crystal 16, linear structures (for example, protrusions 30 and 32, slits 44 and 46) provided on each of the pair of substrates 12 and 14, and outside the pair of substrates 12 and 14 Polarizing plates 26 and 28 are provided.

  FIG. 99 shows one linear structure (projection) 30 of the upper substrate 12 and one linear structure (projection) 32 of the lower substrate 14. The linear structure 30 of the upper substrate includes means 86 similar to the means 56 for forming the boundary of the first type of alignment in which the surrounding liquid crystal molecules described with reference to FIG. The linear structure 32 is also provided with means 86 for forming a boundary of the first type of alignment in which the surrounding liquid crystal molecules are pointed.

  When voltage is applied, as described above, the liquid crystal molecules on the linear structure 30 on the upper substrate and the liquid crystal molecules on the linear structure 32 on the lower substrate are parallel to the linear structures 30 and 32, respectively. The liquid crystal molecules positioned in the gap between the linear structure 30 on the upper substrate and the linear structure 32 on the lower substrate are perpendicular to the linear structures 30 and 32. Oriented as follows.

  Further, for the liquid crystal molecules on the linear structure 30 on the upper substrate, the liquid crystal molecules located in the left region of the boundary forming means 86 are oriented rightward toward the boundary forming means 86 as indicated by arrows. The liquid crystal molecules located in the region on the right side of the boundary forming means 86 are oriented leftward toward the boundary forming means 86 as indicated by arrows. Similarly, for the liquid crystal molecules on the linear structure 32 of the lower substrate, the liquid crystal molecules located in the left region of the boundary forming means 86 have their heads opposite to the boundary forming means 86 as indicated by arrows. The liquid crystal molecules that are oriented in the leftward direction and located in the region on the right side of the boundary forming means 86 are oriented in the right direction in which the head is directed to the opposite side of the boundary forming means 86 as indicated by an arrow.

  Accordingly, when a liquid crystal molecule located on a line perpendicular to the linear structures 30 and 32 (for example, a liquid crystal molecule located in a region on the left side of the boundary forming means 86 surrounded by a dotted circle) is seen as a linear structure. The liquid crystal molecules on the body 30 are oriented rightward (first direction), and the liquid crystal molecules on the linear structure 32 are oriented leftward (second direction opposite to the first direction). That is, for the liquid crystal molecules located in the left region of the boundary forming means 86, the liquid crystal molecules on the linear structure 30 are directed in the opposite direction to the liquid crystal molecules on the linear structure 32. Similarly for the liquid crystal molecules located in the right region of the boundary forming means 86, the liquid crystal molecules on the linear structure 30 are directed in the opposite direction to the liquid crystal molecules on the linear structure 32.

  FIG. 100 is a view showing a modification of the linear structure shown in FIG. In this case, both the linear structures 30 and 32 form means for forming the boundary of the second type of orientation in which a part of the surrounding liquid crystal molecules faces one point and the other liquid crystal molecules face the opposite from the same point. The same means 88 as 58 is provided. Therefore, for the liquid crystal molecules on the linear structure 30 on the upper substrate, the heads of the liquid crystal molecules located in the left region of the boundary forming unit 88 face the opposite side to the boundary forming unit 88 as indicated by arrows. The liquid crystal molecules that are oriented to the left and located in the region on the right side of the boundary forming means 88 are oriented to the right with their heads facing away from the boundary forming means 88 as indicated by arrows. Similarly, for the liquid crystal molecules on the linear structure 32 of the lower substrate, the liquid crystal molecules located in the left region of the boundary forming means 88 are oriented rightward toward the boundary forming means 88 as indicated by arrows. The liquid crystal molecules located in the right region of the boundary forming means 88 are oriented leftward toward the boundary forming means 88 as indicated by arrows.

  Accordingly, regarding the liquid crystal molecules located on the lines perpendicular to the linear structures 30 and 32, the liquid crystal molecules on the linear structures 30 face the first direction and are on the linear structures 32. Some liquid crystal molecules face a second direction opposite to the first direction.

  FIG. 101 is a diagram for explaining a problem of finger pressing in the liquid crystal display device having the linear structures 30 and 32. FIG. 101 shows a state where a point D on the image display surface is pressed with a finger. When the point D on the image display surface is pressed with a finger, a trace of finger pressing may occur at the point D as a display defect. The trace of the finger press disappears when the voltage application is stopped. Even if the voltage is continuously applied, the trace of finger pressing may disappear after a short voltage application time, or may remain without disappearing even after a long voltage application time. There is no problem when the liquid crystal display device is used as a device that does not apply external force such as finger pressing. However, when the liquid crystal display device is used as a device (for example, a touch panel) that applies an external force such as a finger press, there is a problem that a finger press mark is generated on the display surface.

  FIG. 102 is a diagram illustrating an example in which a finger press mark is likely to occur as a comparative example. The upper substrate linear structure 30 includes means 86 for forming the boundary of the first type of orientation, while the lower substrate linear structure 32 has a portion of the surrounding liquid crystal molecules facing one point and the other. Means 88 are provided for forming a second type of alignment boundary in which the liquid crystal molecules face the same point from the opposite. Therefore, the liquid crystal molecules on the linear structure 30 on the upper substrate face the same direction as the liquid crystal molecules on the linear structure 32 on the lower substrate. For example, for the liquid crystal molecules on the linear structure 30 on the upper substrate, the liquid crystal molecules located in the left region of the boundary forming means 86 are oriented leftward, and the liquid crystal molecules on the linear structure 32 on the lower substrate are aligned. With respect to, the liquid crystal molecules located in the left region of the boundary forming means 88 are oriented leftward.

  When the finger is pressed, the liquid crystal molecules on the linear structures 30 and 32 move toward the gaps between the linear structures 30 and 32, and the linear structures 30 and 32 are connected. A portion 16 m of the liquid crystal molecules in the gap is parallel to the linear structures 30 and 32. Although the liquid crystal molecules in the gap between the linear structures 30 and 32 must be perpendicular to the linear structures 30 and 32, the linear structure is present at the portion where the finger is pressed. Disclination occurs because a part of the liquid crystal molecules 16m in the gap between the bodies 30 and 32 are parallel to the linear structures 30 and 32, and as a result, a trace of finger pressing occurs.

  As shown in FIG. 102, when the liquid crystal molecules on the linear structures 30 and 32 of the two substrates are oriented in the same direction, the linear structures 30 from the linear structures 30 and 32 are displayed. , 32 are also directed toward the same direction as the liquid crystal molecules on the linear structures 30, 32, and the liquid crystal molecules are linear from one linear structure 30. The orientation is continuous over the gap between the structures 30 and 32 and the other linear structure 32, and the trace of finger pressing does not disappear for a long time.

  On the other hand, in the example of FIGS. 99 and 100, when there is a finger press, as in the example of FIG. 102, one of the liquid crystal molecules on the linear structures 30 and 32 is obtained. The portion 16m is pushed toward the gap between the linear structures 30 and 32 and is parallel to the linear structures 30 and 32. However, in this case, since the liquid crystal molecules on the linear structures 30 and 32 of the two substrates are directed in opposite directions, the extruded liquid crystal molecules 16m are on the linear structures of one substrate. The liquid crystal molecules face the same direction, but face the opposite direction to the liquid crystal molecules on the linear structure of the other substrate, and are not continuously aligned with the liquid crystal molecules on the other linear structure. Since adjacent liquid crystal molecules must be continuously aligned, the extruded liquid crystal molecules 16m attempt to rotate in a direction perpendicular to the linear structures 30, 32 as indicated by arrows. For this reason, the trace of finger press disappears in a short time.

  103 and 104 are views showing an example of the boundary forming means 86 of FIG. The linear structure 30 of the upper substrate is a protrusion, and for the linear structure 30 of the upper substrate 12, the means 86 for forming the boundary of the first type orientation is a small protrusion provided on the lower substrate 14. 86a. The linear structure 32 of the lower substrate 14 is a protrusion, and for the linear structure 32 of the lower substrate 14, the means 86 for forming the boundary of the first type of orientation is a small size provided on the upper substrate 12. It consists of a protrusion 86b. The small protrusion 86 a and the small protrusion 86 b are provided on a line perpendicular to the linear structures 30 and 32.

  105 and 106 are diagrams showing examples of the boundary forming means 88 of FIG. The linear structure 30 of the upper substrate is a protrusion, and for the linear structure 30 of the upper substrate 12, the means 88 for forming the boundary of the second type of orientation is a small protrusion provided on the upper substrate 12. 88a. The linear structure 32 of the lower substrate 14 is a protrusion. For the linear structure 32 of the lower substrate 14, the means 88 for forming the boundary of the second type of orientation is provided on the lower substrate 14. It consists of protrusion 88b. The small protrusion 88a and the small protrusion 88b are provided on a line perpendicular to the linear structures 30 and 32. 103 to 106, the small protrusions 86 a and 86 b are longer than the width of the linear structures 30 and 32 and extend so as to be orthogonal to the linear structures 30 and 32. For example, the linear structures 30 and 32 have a width of 10 μm and a height of 1.5 μm, and the small protrusions 86a and 86b have a width of 10 μm, a height of 1.5 μm, and a length of 14 μm. The small protrusions 86a and 86b can be formed of a dielectric.

  FIG. 107 is a diagram showing an example of the boundary forming means 86 of FIG. The linear structure 30 of the upper substrate is a protrusion, and for the linear structure 30 of the upper substrate 12, means 86 for forming the boundary of the first type orientation is provided on the electrode of the lower substrate 14. It consists of a small slit 86c. The linear structure 32 of the lower substrate 14 is a protrusion, and for the linear structure 32 of the lower substrate 14, means 86 for forming the boundary of the first type orientation is provided on the electrode of the upper substrate 12. It consists of a small slit 86d. The small slit 86 c and the small slit 86 d are provided on a line perpendicular to the linear structures 30 and 32.

  FIG. 108 is a diagram showing an example of the means 88 of FIG. The linear structure 30 of the upper substrate is a protrusion, and the means 88 for forming the boundary of the second type orientation with respect to the linear structure 30 of the upper substrate 12 is a small slit provided in the upper substrate 12. 88c. The linear structure 32 of the lower substrate 14 is a protrusion, and means 88 for forming a boundary of the second type of orientation with respect to the linear structure 32 of the lower substrate 14 is a small element provided on the lower substrate 14. It consists of a slit 88d. The small slit 88 c and the small slit 88 d are provided on a line perpendicular to the linear structures 30 and 32. 107 and 108, the small slits 88 c and 88 d are longer than the width of the linear structures 30 and 32 and extend so as to be orthogonal to the linear structures 30 and 32.

  In FIGS. 99 to 108, the protrusions are shown as the linear structures 30 and 32, but it goes without saying that slits can be used as the linear structures 30 and 32. Also in this case, small protrusions or small slits can be used as the means 86 and 88. Also, the two means 86 for the upper substrate and the lower substrate can be a combination of a small protrusion and a small slit, and the two means 88 for the upper substrate and the lower substrate can be a combination of a small protrusion and a small slit. it can. Thus, according to the present embodiment, a liquid crystal display device having high impact resistance can be obtained.

  FIG. 109 is a diagram showing a linear structure of a liquid crystal display device according to the tenth embodiment of the present invention. 110 is a cross-sectional view of the liquid crystal display device of FIG. Also in this case, as in the previous embodiment, the liquid crystal display device includes a pair of substrates 12 and 14 and a liquid crystal 16 having a negative dielectric anisotropy inserted between the pair of substrates 12 and 14. In order to control the alignment of the liquid crystal 16, linear structures (for example, protrusions 30 and 32, slits 44 and 46) provided on each of the pair of substrates 12 and 14, and outside the pair of substrates 12 and 14 And a polarizing plate (not shown) disposed respectively.

  In this embodiment, the linear structure 30 of the upper substrate 12 is a protrusion 30, and the linear structure 32 of the lower substrate 14 is a protrusion 32. The sub-wall structure 90 is provided on the lower substrate 14 between the linear structures 30 and 32 of the pair of substrates 12 and 14 when viewed from the normal direction of the pair of substrates 12 and 14. The sub-wall structure 90 is provided as a diamond-shaped slit. The sub-wall structure 90 is long in the direction perpendicular to the linear structures 30 and 32, and is arranged along the linear structures 30 and 32 at a constant pitch (5 to 50 μm).

  FIG. 111 is a diagram showing a modification of the liquid crystal display device of FIG. In this example, the linear structure 30 of the upper substrate 12 is a protrusion 30, and the linear structure 32 of the lower substrate 14 is a protrusion 32. The sub-wall structure 90 provided between the linear structures 30 and 32 of the pair of substrates 12 and 14 is provided as a rectangular slit. The sub-wall structure 90 is long in the direction perpendicular to the linear structures 30 and 32, and is arranged at a constant pitch along the linear structures 30 and 32.

  112 and 113 are diagrams showing modifications of the liquid crystal display device of FIG. In this example, the linear structure 30 of the upper substrate 12 is a protrusion 30, and the linear structure 32 of the lower substrate 14 is a protrusion 32. The sub-wall structure 90 provided between the linear structures 30 and 32 of the pair of substrates 12 and 14 is provided as a square-shaped protrusion. The secondary wall structures 90 are arranged at a constant pitch along the linear structures 30 and 32.

  114 and 115 show a modification of the liquid crystal display device of FIG. In this example, the linear structure 30 of the upper substrate 12 is a protrusion 30, and the linear structure 32 of the lower substrate 14 is a protrusion 32. The linear structures 30 and 32 are formed in a shape having a bent portion. The sub-wall structure 90 provided between the linear structures 30 and 32 of the pair of substrates 12 and 14 is provided as a rectangular slit. The sub-wall structure 90 is long in the direction perpendicular to the linear structures 30 and 32, and is arranged at a constant pitch along the linear structures 30 and 32.

  The operation of the liquid crystal display device of FIGS. 109 to 115 will be described. In the liquid crystal display device in which the linear structures 30 and 32 are provided on the pair of substrates 12 and 14 in order to control the alignment of the liquid crystal, there is a feature that rubbing is not necessary and the viewing angle characteristics can be improved. Since the distance between the cooperating linear structures 30 and 32 is long, the response of the liquid crystal is low when a voltage is applied. By providing the sub-wall structure 90 between the linear structures 30 and 32, the liquid crystal is easily aligned even in the gap between the linear structures 30 and 32, and there is no sub-wall structure 90. In comparison, the response of the liquid crystal is improved.

  More specifically, in the liquid crystal display device in which the linear structures 30 and 32 are provided on the pair of substrates 12 and 14, the liquid crystal molecules are aligned perpendicular to the substrate surface, and the direction determined when a voltage is applied. Fall down. The liquid crystal molecules located in the middle between the cooperating linear structures 30 and 32 are not sure in which direction they will fall immediately after applying a voltage. It falls in a certain direction. For this reason, the responsiveness is low. With the sub-wall structure 90, the liquid crystal molecules located in the middle between the cooperating linear structures 30, 32 are defined in a direction to be tilted, and tilt in a certain direction immediately after applying a voltage, This improves the responsiveness.

  In the example of FIGS. 109 to 115, the linear structures 30 and 32 are both formed as protrusions, and a sub-wall structure 90 made of protrusions or slits is provided for them. On the other hand, the linear structures 30 and 32 are both formed as slits, or one linear structure can be used as a protrusion and the other linear structure can be used as a slit. Even in this case, the sub-wall structure 90 may be formed of a protrusion or a slit. Since the protrusions and the slits have substantially the same function with respect to the alignment of the liquid crystal and have substantially the same effect, either of the sub-wall structures 90 may be provided. Although there is no restriction | limiting in particular in a shape, The good result is obtained by making a rhombus.

  In the case where a slit is provided as the sub-wall structure 90, the length of the slit is preferably as long as possible in order to enhance the effect of the slit in the direction perpendicular to the linear structures 30, 32, and between the linear structures 30, 32. The length of the gap should be approximately the same. If the slit becomes longer in the direction parallel to the linear structures 30 and 32, the electrode portion becomes smaller (when the slit is provided on the electrode), and if it is too short, the slit itself becomes difficult to form. It is desirable to be. Next, the interval between the slits is too long. However, if the length is too long, the effect of the slit is reduced. If the length is too short, the alignment of the liquid crystal is disturbed by the influence of the slits.

  When the protrusion is provided as the sub-wall structure 90, the conditions are slightly different from those of the slit. First of all, the size of the protrusion is not desirable because the transmittance of the liquid crystal display device is lowered if it is too large, and if it is too small, the formation of the protrusion itself becomes difficult and the effect is reduced. Therefore, it is desirable that the vertical direction and the parallel direction with respect to the linear structures 30 and 32 are about 5 μm. Next, the interval between the protrusions is preferably about 5 to 30 μm for the same reason as in the case of the slit and for the purpose of not sacrificing the transmittance.

  If conductive protrusions are used as the sub-wall structure 90, the gap between the protrusions can be widened, which is more desirable for the purpose of not sacrificing transmittance. At this time, the protrusion gap can be expanded to about 50 μm. In order to form conductive protrusions, ITO may be sputtered after the protrusions are formed on a substrate having no ITO electrode.

  When a slit or a protrusion is provided as the sub-wall structure 90, it is not necessary to provide the sub-wall structure 90 on both of the substrates 12 and 14, and it may be provided only on one side.

  FIG. 116 is a view showing a method for manufacturing the substrate 14 having the linear structure 32 and the sub-wall structure 90. As shown in (A), first, a substrate 14 on which ITO is formed is prepared. When the substrate 14 is a TFT substrate, a TFT and an active matrix are formed on the substrate, and ITO is deposited. A positive resist (LC200 (manufactured by Shipley Far East)) 91 was spin-coated on the substrate 14 under conditions of 1500 rpm and 30 s. Although a positive resist is used here, the resist is not necessarily a positive resist, a negative resist may be used, and a photosensitive resin other than a resist may be used. After the spin-coated resist 91 was pre-baked at 90 ° C. for 20 minutes, contact exposure was performed on the resist 91 through a photomask 92 for ITO patterning (exposure time 5 s).

  Next, as shown in (B), the resist 91 is developed with a developer MF319 manufactured by Shipley Far East (development time 50 s), and post-baking is performed at 120 ° C. for 1 hour and then at 200 ° C. for 40 minutes after development. It was. As shown in (C), the ITO of the substrate 14 was etched using an ITO etchant (mixed ferric chloride, hydrochloric acid, and pure water) heated to 45 ° C. (etching time 3 minutes). As shown in (D), the resist 91 was peeled off using acetone to produce a substrate 14 with an ITO electrode having a patterned subwall structure (slit) 90.

  The patterned ITO becomes the pixel electrode 22, and the sub-wall structure (slit) 90 is formed in the pixel electrode 22. The sub-wall structure (slit) 90 produced at this time was rectangular, and the long side was 20 μm, the short side was 5 μm, and the long side was perpendicular to the linear structure 32. The interval between the sub-wall structures (slits) 90 was 10 μm in the direction orthogonal to the linear structure 32 and 20 μm in the parallel direction.

  As shown in (E), a resist (LC200) 93 is spin coated in the same manner as above on the substrate 14 patterned with the ITO electrode thus produced, and exposed through a photomask 94 for forming protrusions. A shaped structure (projection) 32 was formed. At this time, the sub-wall structure (slit) 90 of the ITO electrode was arranged between the linear structures 30 and 32. (F) shows the linear structure (projection) 32 thus formed. The width of the linear structures (projections) 32 was 10 μm, the height was 1.5 μm, and the distance between the linear structures 30 and 32 when the upper and lower substrates 12 and 14 were stacked was 20 μm. In this example, the sub-wall structure (slit) 90 is formed first, but the linear structure (projection) 32 may be formed first.

  Next, a vertical alignment film JALS684 (manufactured by JSR) was spin-coated under the conditions of 200 rpm and 30 s and baked at 180 ° C. for 1 hour to form a vertical alignment film. A seal (XN-21F, manufactured by Mitsui Toatsu Chemical Co., Ltd.) is formed on one substrate, and a 4.5 μm spacer (SP-20045, manufactured by Sekisui Fine Chemical) is sprayed on the other substrate. Superposed (G). Finally, baking was performed at 135 ° C. for 90 minutes to prepare an empty panel. Liquid crystal MJ961213 (manufactured by Merck) having negative dielectric anisotropy was injected into this empty panel in a vacuum. Next, the inlet was sealed with a sealing material (30Y-228, manufactured by ThreeBond) to produce a liquid crystal panel (G).

  In this example, the interval between the sub-wall structures (slits) 90 is set to 20 μm in the direction parallel to the linear structures 32. A liquid crystal display device in which the distance between the sub-wall structures (slits) 90 is 20 μm in the direction parallel to the linear structures 32 was manufactured separately by the same manufacturing method.

  FIG. 117 is a diagram showing another example of a method for manufacturing a substrate having a linear structure and a sub-wall structure. As shown in (A), a positive resist (LC200 (manufactured by Shipley Far East)) 90a was spin-coated on a substrate 14 having an ITO electrode (not shown) under the conditions of 2000 rpm and 30 s. The spin-coated resist 90a was pre-baked at 90 ° C. for 20 minutes, and then contact exposure was performed through a photomask 92a (exposure time 5 s).

  Next, as shown in (B), the resist 90a is developed with a developer MF319 manufactured by Shipley Far East (development time 50 s), and after the development, post-baking is performed at 120 ° C. for 1 hour and then at 200 ° C. for 40 minutes. Subwall structure (projection) 90 was formed. The size of the sub-wall structure (projection) 90 was a 5 μm square, the height was 1 μm, and the spacing between the projections was 25 μm (C).

  As shown in (D), a resist (LC200) 93 is spin-coated on the substrate 14 thus fabricated and exposed through a photomask 94 for forming protrusions in the same manner as described above. 90 is located between the linear structures 30 and 32. Similarly, the other substrate 12 was formed and the upper and lower substrates were stacked (E). The width of the linear structures (projections) 32 was 10 μm, the height was 1.5 μm, and the distance between the linear structures 30 and 32 when the upper and lower substrates 12 and 14 were stacked was 20 μm.

  In yet another example, the sub-wall structure 90 is formed of a conductive protrusion. A manufacturing method in this case will be described. A sub-wall structure (protrusion) 90 was formed in the same manner as in the above example using a positive resist (LC200 (manufactured by Shipley Far East)) on a pair of substrates having no ITO electrode. The size of the sub-wall structure (projection) 90 was a square of 5 μm square, the height was 1 μm, and the spacing between the projections was 25 μm in the direction orthogonal to the linear structure 32 and 50 μm in the parallel direction. Next, ITO was sputtered onto the substrate 14 having the sub-wall structure (protrusion) 90 and etched to form the pixel electrode 22. The sub-wall structure (protrusion) 90 is covered with ITO and formed as a conductive protrusion. Then, a linear structure (projection) 32 is formed, and the two substrates 12 and 14 are overlaid. Needless to say, the linear structure (projection) 32 may be formed first.

118 shows the response when the width of the sub-wall structure (slit) 90 is constant (5 μm) and the distance between the sub-wall structures (slit) 90 is changed to 10, 20, 30, 50 μm in the liquid crystal display device of FIG. FIG. Measured at 25 ° C. The comparative example is an example of a liquid crystal display device that has linear structures 30 and 32 but does not have a sub-wall structure (slit) 90. From this result, the response speed when the interval between the sub-wall structures (slits) 90 is 10, 20, and 30 μm is smaller than the response speed of the comparative example, and the response when the interval between the sub-wall structures (slits) 90 is 50 μm. The speed is larger than the response speed of the comparative example. Therefore, the interval between the sub-wall structures (slits) 90 should be 50 μm or less, and more certainly 30 μm or less. Further, when the interval between the sub-wall structures (slits) 90 is 10 μm or less, the transmittance is greatly reduced, and the interval between the sub-wall structures (slits) 90 is about 5 μm as a lower limit in terms of resist resolution. In addition, the transmittance | permeability for every space | interval of the subwall structure (slit) 90 was as follows.
Comparative Example 10 μm 20 μm 30 μm 50 μm
24.0% 22.7% 23.5% 23.8% 24.2%

FIG. 119 shows the response when the interval between the sub-wall structures (slits) 90 is constant (20 μm) and the width of the sub-wall structures (slits) 90 is changed to 5, 10, and 20 μm in the liquid crystal display device of FIG. FIG. From this result, the response speed when the width of the sub-wall structure (slit) 90 is 5, 10, 20 μm is smaller than the response speed of the comparative example. However, when the width of the sub-wall structure (slit) 90 is 20 μm or more, the transmittance decreases. Therefore, the width of the sub-wall structure (slit) 90 is preferably about 5 to 10 μm. In addition, the transmittance | permeability for every width | variety of the subwall structure (slit) 90 was as follows.
Comparative example 5 μm 10 μm 20 μm
24.0% 23.5% 22.7% 20.8%

FIG. 120 shows the liquid crystal display device of FIG. 112 when the size of the sub-wall structure (projection) 90 is constant (5 μm square) and the interval between the sub-wall structures (projections) 90 is changed to 10, 20, 50, and 70 μm. It is a figure which shows responsiveness. From this result, since the response speed when the interval between the sub-wall structures (projections) 90 is 70 μm is larger than the response speed of the comparative example, the interval between the sub-wall structures (projections) 90 should be 50 μm or less. . Further, when the distance between the sub-wall structures (projections) 90 is 10 μm or less, the transmittance is lowered, and the distance between the sub-wall structures (projections) 90 is about 5 μm as a lower limit in terms of resist resolution. In addition, the transmittance | permeability for every space | interval of the subwall structure (protrusion) 90 was as follows.
Comparative Example 10 μm 20 μm 50 μm 70 μm
24.0% 22.3% 23.1% 23.8% 24.2%

FIG. 121 shows responsiveness of the liquid crystal display device of FIG. 112 when the interval of the sub-wall structure (hour) 90 is constant (20 μm) and the size of the sub-wall structure (projection) 90 is changed to 5, 10 μm square. FIG. From this result, the response speed when the size of the sub-wall structure (projection) 90 is 5 μm square is almost the same as the response speed when the size of the sub-wall structure (projection) 90 is 10 μm square. However, when the size of the sub-wall structure (protrusion) 90 is 5 μm, the transmittance decreases. Therefore, the size of the sub-wall structure (projection) 90 is preferably about 5 μm square. In addition, the transmittance | permeability for every magnitude | size of the subwall structure (protrusion) 90 was as follows.
Comparative example 5 μm 10 μm
24.0% 23.1% 20.6%

  FIG. 122 is a view showing a liquid crystal display device according to a tenth embodiment of the present invention. Also in this case, as in the previous embodiment, the liquid crystal display device includes a pair of substrates 12 and 14 and a liquid crystal 16 having a negative dielectric anisotropy inserted between the pair of substrates 12 and 14. In order to control the alignment of the liquid crystal 16, linear structures (for example, protrusions 30 and 32, slits 44 and 46) provided on each of the pair of substrates 12 and 14, and outside the pair of substrates 12 and 14 Polarizing plates 26 and 28 are provided.

  FIG. 122 shows one linear structure (projection) 30 of the upper substrate 12 and one linear structure (projection) 32 of the lower substrate 14. Further, the sub-wall structure 96 is provided on at least one of the pair of substrates 12 and 14 between the linear structures 30 and 32 of the pair of substrates as viewed from the normal direction of the pair of substrates. In this embodiment, the sub-wall structure 96 is formed on the lower substrate 14 as a substantially flat strip-shaped protrusion 96 </ b> A having a width wider than that of the linear structure 32 in parallel with the linear structure 32. The linear structure 32 is formed as a two-step protrusion on the sub-wall structure 96. The width of the strip-shaped protrusion 96 </ b> A is substantially equal to the width of the pixel electrode 22, and the linear structure 32 extends on the center line of the sub-wall structure 96, so that the side edge of the sub-wall structure 96 passes through the center of the pixel electrode 22. The parameter that changes in one direction is the height of the belt-like protrusion 96A.

  In this configuration, the liquid crystal is obliquely aligned depending on the shape at the side edge of the sub-wall structure 96. Further, when the dielectric constant of the sub-wall structure 96 is smaller than the dielectric constant of the liquid crystal, when an electric field is applied, the electric field (electric field lines EL) ) Is inclined, and the liquid crystal is oriented obliquely. The tilt of the liquid crystal is restricted not only by the linear structure 32 but also by the sub-wall structure 96, and the tilt of the liquid crystal propagates to the entire pixel immediately after voltage application, so the response time is shortened.

  FIG. 123 is a diagram showing a modification of the liquid crystal display device of FIG. In this example, the sub-wall structure 96 includes a conductive protrusion 96 </ b> B provided on the substrate 12 facing the linear structure 32. The parameter that changes in one direction is the height of the conductive protrusion 96 </ b> B formed on the counter substrate 12. At the side edge of the conductive protrusion 96B, the liquid crystal is obliquely aligned depending on the shape. Further, from the shape of the conductive protrusion 96B, when an electric field is applied, the electric field is inclined and the liquid crystal is obliquely aligned. Not only the linear structure 32 but also the sub-wall structure 96 is restricted, and the tilt of the liquid crystal propagates to the entire pixel immediately after the voltage is applied, so the response time is shortened.

  124 is a diagram showing a method of manufacturing the liquid crystal display device of FIG. As shown in (A), ITO 22 is formed on the glass substrate 14, and a film 96 a to be a strip-shaped protrusion 96 A of the sub-wall structure 96 is formed. As shown in (B), the projection film 96a is exposed to ultraviolet rays UV using a mask M and developed to form a strip-like projection 96A of the sub-wall structure 96 (C). As shown in (D), a film 32m to be a linear structure 32 is formed, and using the mask M, the film 32m of the linear structure 32 is exposed with ultraviolet UV, developed, and developed into a line. A shaped structure 32 is formed (E).

  125 is a diagram showing a method of manufacturing the liquid crystal display device of FIG. As shown in FIG. 5A, a film 96b to be a band-shaped protrusion 96B of the sub-wall structure 96 is formed on the glass substrate 12. As shown in (B), the projection film 96b is exposed to ultraviolet rays UV using a mask M, and developed to form a strip-like projection 96B of the sub-wall structure 96 (C). As shown in (D), an ITO film to be the pixel electrode 22 is formed by vapor deposition, and then a film to be a linear structure 30 is formed as shown in (E).

  FIG. 126 shows an example in which the linear structure of the lower substrate 14 is a slit 46. The sub-wall structure 96 includes a conductive protrusion 96 </ b> C formed on the opposite side of the linear structure 46. The linear structure 46 formed by the slits 46 is generated in a direction in which electric lines of force spread toward the slits. When the dielectric constant of the subwall structure 96 is lower than that of the liquid crystal, the lines of electric force are generated in a direction spreading toward the slit 46.

  FIG. 127 shows an example in which the linear structure of the lower substrate 14 is a slit 46. Similar to the example of FIG. 122, the sub-wall structure 96 includes a strip-shaped protrusion 96 </ b> A formed on the lower side of the linear structure 46. The linear structure 46 formed by the slits 46 is generated in a direction in which electric lines of force spread toward the slits. When the dielectric constant of the subwall structure 96 is lower than that of the liquid crystal, the lines of electric force are generated in a direction spreading toward the slit 46.

  FIG. 128 shows an example in which the sub-wall structure 96 is formed in two steps on the lower substrate 14 and includes band-shaped protrusions 96D and 96E. The lower belt-like projection 96D is wider than the upper belt-like projection 96E, and the projection 32, which is a linear structure 32, is formed on the upper belt-like projection 96E. In this case, the tilt alignment of the liquid crystal can be regulated by the two side edges of the belt-like protrusions 96D and 96E formed in two steps. In this configuration, since the propagation distance of the alignment tilt of the liquid crystal is shortened from one half to one third, the response time is greatly improved.

  In FIG. 129, the sub-wall structure 96 has a band-like shape in which the thickness is increased under the linear structure 32 of the lower substrate 14 and is inclined outward so that the thickness decreases as the distance from the linear structure 32 increases. It consists of a protrusion 96F. Since the strip-shaped protrusion 96F having a large area is inclined, the tilt alignment of the liquid crystal can be regulated by the difference in shape and relative permittivity over a wide area. Furthermore, it is possible to reduce leakage light due to the shape of the edge when no voltage is applied. The inclined structure can be formed by reflowing a photosensitive material.

  FIG. 130 shows an example in which undulating protrusions 98 are formed on the lower substrate 14, and the protrusions 98 act as the linear structures 32 and sub-wall structures 96. The undulation period is changed, and the parameter changing in one direction is the undulation period. As the undulation period becomes longer, the regulating force for tilting the liquid crystal becomes weak on average. Furthermore, since the electric field distribution is also inclined on average, the liquid crystal can be inclined and aligned. Therefore, the tilt alignment of the liquid crystal can be regulated in a wide area.

  FIG. 131 shows an example in which a protrusion 97 having a changed dielectric constant is formed on the lower substrate 14, and this protrusion 97 acts as the linear structure 32 and the sub-wall structure 96. The protrusion 97 includes a portion whose relative dielectric constant is gradually reduced to ε1, ε2, and ε3. Since the electric field tilt occurs in the region where the relative dielectric constant changes, the tilt alignment of the liquid crystal can be regulated. The relative dielectric constant of the protrusion 97 may be continuously changed.

  FIG. 132 shows an example in which the pixel electrode 22 is composed of a conductor 99A having a low resistivity and a conductor 99B having a high resistivity. The conductor 99A having a low resistivity is narrower than the conductor 99B having a high resistivity, is covered with the conductor 99B having a high resistivity, and is located at the center of the conductor 99B having a high resistivity. According to this, since the electric field gradient is generated in the process in which the charge is diffused from the conductor 99B in the time determined by the time constant of the capacitance of the electrode 18 on the counter substrate side and the conductor 99B having a high conductor resistivity, The tilt orientation can be regulated.

  133A to 133C are views showing an embodiment in which irregularities are formed in the shape of the end of the projection as the sub-wall structure 96. FIG. In (A), the shape of the end of the protrusion as the sub-wall structure 96 is formed in a triangular wave shape 96H. In (B), the shape of the end of the projection as the auxiliary wall structure 96 is formed in a curved shape 96I. In (C), the shape of the end of the protrusion as the sub-wall structure 96 is formed in a rectangular wave shape 96J. By forming irregularities in the shape of the ends of the protrusions, the alignment of the liquid crystal can be stabilized. When the liquid crystal is tilted, the alignment tends to be aligned parallel to the protrusions. In the sub-wall structure 96, the liquid crystal needs to be aligned perpendicular to the protrusions. If the shape of the end of the protrusion is uneven, forces that try to be parallel to the protrusion cancel each other, and as a result, the liquid crystal is aligned perpendicular to the protrusion.

  FIGS. 134A to 134C are views showing an embodiment in which a cross section of a projection as the auxiliary wall structure 96 is defined. In (A), the cross-sectional shape of the protrusion as the sub-wall structure 96 is formed in a trapezoidal shape 96K. In (B), the shape of the cross section of the projection as the sub-wall structure 96 is formed in an arc shape 96L. In (C), the shape of the cross section of the protrusion as the sub-wall structure 96 is formed into a curved shape 96M. By doing in this way, it becomes possible to expand the area | region which controls the inclination orientation of a liquid crystal. Furthermore, when the cross section is steep, the liquid crystal alignment is disturbed depending on the shape when no voltage is applied. When the cross-sectional shape is made smooth, it becomes possible to reduce the leakage light caused by the alignment failure due to the edge.

  Further embodiments can be configured for the embodiments described with reference to FIGS. 122-134. For example, in the above embodiment, the structure that regulates the tilt alignment of the liquid crystal is formed only on one substrate side, but the structure that regulates the tilt orientation of the liquid crystal can be formed on both substrates. If it does so, the cell thickness in a pixel will become comparatively uniform, and an optical characteristic will become uniform. Further, the force for regulating the tilt alignment of the liquid crystal becomes strong.

  In addition, when the liquid crystal is driven by the TFT, the protrusion manufacturing process can be simplified by forming the protrusion with a gate insulating film such as silicon nitride or a final protective film. When a chiral material is added to the liquid crystal, the response time of the liquid crystal when the electric field is reduced can be shortened. The return of the liquid crystal alignment is accelerated by the twist energy of the liquid crystal.

  In this way, the second liquid crystal tilt alignment regulating means (sub-wall structure) in which the parameter increases or decreases in one direction from the linear structure between the linear structures that control the alignment of the liquid crystal is formed. Therefore, the tilt direction of the liquid crystal alignment can be regulated, and the propagation speed in the tilt direction of the liquid crystal alignment at the transition from black display to white display is shortened, so that the response time can be shortened. It greatly contributes to display performance.

  As described above, according to the present invention, it is possible to manufacture a liquid crystal display device with improved luminance and quick response speed. The orientation direction of all the domains formed on the linear structure can be determined, and the change with time of the domains can be suppressed, so that overshoot can be improved.

It is a schematic sectional drawing which shows a liquid crystal display device. It is a schematic sectional view showing a vertical alignment type liquid crystal display device having a linear structure for controlling the alignment of liquid crystal. It is a top view which shows 1 pixel and a linear structure. It is a figure which shows the liquid crystal molecule which fell down in the voltage application according to the linear structure of FIG.2 and FIG.3. It is a top view which shows the other example of a linear structure. It is a schematic sectional drawing which shows a liquid crystal display device when both the linear structures of a pair of board | substrate are protrusions. FIG. 6 is a schematic cross-sectional view showing a liquid crystal display device when the linear structure of one substrate is a protrusion and the linear structure of the other substrate is a slit structure. It is a schematic sectional drawing which shows a liquid crystal display device when both the linear structures of a pair of board | substrate are slit structures. It is sectional drawing which shows the example of the linear structure which is protrusion. It is sectional drawing which shows the example of the linear structure which is a slit structure. It is a figure explaining the problem of the orientation of the liquid crystal display device which has a linear structure. It is a figure which shows the transmittance | permeability in several area | regions of FIG. It is a figure which shows the luminance overshoot. It is a figure which shows the example of the linear structure by 1st Example of this invention. It is a figure which shows the modification of a linear structure. It is a figure which shows the modification of a linear structure. It is a figure which shows the modification of a linear structure. It is a figure which shows the modification of a linear structure. It is a figure which shows the modification of a linear structure. It is a figure which shows the modification of a linear structure. It is a figure which shows the modification of a linear structure. It is a figure which shows the pixel electrode and slit structure of FIG. It is a figure explaining formation of the linear structure which consists of protrusions. It is a figure which shows the orientation of the liquid crystal of the liquid crystal display device which has a linear structure. It is a figure which shows the display characteristic in the structure of FIG. It is a figure which shows the orientation of the liquid crystal of the liquid crystal display device which has a linear structure which consists of a some structural unit. It is a figure which shows the display characteristic in the structure of FIG. It is a figure which shows the orientation of the liquid crystal of the liquid crystal display device which has a linear structure by 2nd Example of this invention. It is a figure which shows the display characteristic in the structure of FIG. FIG. 4 is a diagram illustrating a first type orientation boundary feature and a second type orientation boundary feature. It is a top view which shows the specific example of the linear structure of FIG. It is sectional drawing which passes along the linear structure of FIG. It is a top view which shows the modification of a linear structure. It is sectional drawing which passes along the linear structure of FIG. It is a top view which shows the modification of a linear structure. It is a top view which shows the modification of a linear structure. It is a top view which shows the modification of a linear structure. It is sectional drawing of the part near the edge of the pixel electrode of a liquid crystal display device. It is a figure which shows the orientation of the liquid crystal in the edge of the pixel electrode of FIG. It is a top view which shows the modification of a linear structure. It is a top view which shows the modification of a linear structure. It is a top view which shows the modification of a linear structure. It is a top view which shows the linear structure by 3rd Example of this invention. FIG. 44 is a cross-sectional view of a liquid crystal display device that passes through the linear structure in FIG. 43. It is a figure which shows the orientation of the liquid crystal of the vicinity of the linear structure of FIG. It is a figure which shows the orientation of the liquid crystal of the vicinity of the linear structure of 1st Example. It is sectional drawing which shows the modification of the linear structure and the control means of orientation of a boundary. It is sectional drawing which shows the modification of the linear structure and the control means of orientation of a boundary. It is sectional drawing which shows the modification of the linear structure and the control means of orientation of a boundary. It is sectional drawing which shows the modification of the linear structure and the control means of orientation of a boundary. It is a top view which shows the modification of the linear structure and the control means of the orientation of a boundary. FIG. 52 is a cross-sectional view taken along line 52-52 of FIG. 51. FIG. 53 is a cross-sectional view taken along line 53-53 of FIG. 51. It is a top view which shows the modification of the linear structure and the control means of the orientation of a boundary. FIG. 55 is a cross-sectional view of a liquid crystal display device that passes through the linear structure in FIG. 54. It is a top view which shows the modification of the linear structure and the control means of the orientation of a boundary. FIG. 57 is a cross-sectional view of a liquid crystal display device that passes through the linear structure in FIG. 56. It is a top view which shows the linear structure by 4th Example of this invention. FIG. 59 is a schematic cross-sectional view of a liquid crystal display device taken through line 59-59 in FIG. 58. It is a top view which shows the modification of a linear structure. FIG. 61 is a plan view showing a pixel electrode having the slit structure of FIG. 60. It is a top view which shows the modification of a linear structure. It is a top view which shows the modification of a linear structure. It is a top view which shows the modification of a linear structure. It is a top view which shows the modification of a linear structure. It is a top view which shows the linear structure by 5th Example of this invention. It is a top view which shows the typical example of the linear structure with a bending. FIG. 68 is a diagram illustrating a problem of a liquid crystal display device having the linear structure of FIG. 67. It is a top view which shows the modification of a linear structure. It is a top view which shows the modification of a linear structure. It is a top view which shows the modification of a linear structure. It is a top view which shows the modification of a linear structure. It is a top view which shows the modification of a linear structure. It is a top view which shows the modification of a linear structure. It is a figure which shows the relationship between the linear structure of the liquid crystal display device by 6th Example of this invention, and a polarizing plate. FIG. 76 is a diagram showing display brightness in the configuration of FIG. 75. It is a figure which shows the relationship between the angle of the director of the liquid crystal for every micro area | region, and its frequency in the liquid crystal display device which has a linear structure for controlling the orientation of a liquid crystal. FIG. 76 is a diagram showing a relationship between a linear structure and a polarizing plate of a liquid crystal display device according to a modified example of the example in FIG. 75. FIG. 79 is a cross-sectional view of the liquid crystal display device of FIG. 78. FIG. 76 is a diagram showing a relationship between a linear structure and a polarizing plate of a liquid crystal display device according to a modified example of the example in FIG. 75. It is sectional drawing of the liquid crystal display device of FIG. It is a figure which shows the linear structure of the liquid crystal display device by 7th Example of this invention. FIG. 83 is a cross-sectional view taken along line 83-83 of the liquid crystal display device of FIG. FIG. 83 is a diagram showing a more specific example of the linear structure in FIG. 82. FIG. 83 is a diagram showing a comparative example of the linear structure in FIG. 82. It is a figure which shows the modification of the linear structure of FIG. FIG. 87 is a cross-sectional view of the liquid crystal display device having the linear structure of FIG. 86 taken along line 87-87. It is a figure which shows the linear structure of the liquid crystal display device by 8th Example of this invention. FIG. 89 is a cross-sectional view of the liquid crystal display device having the linear structure of FIG. 88 taken along line 87-87. It is a figure which shows the modification of the linear structure of FIG. FIG. 90 is a cross-sectional view through a liquid crystal display device having the linear structure of FIG. It is a figure which shows the modification of the linear structure of FIG. FIG. 93 is a cross-sectional view of the linear structure in FIG. 92. It is a figure which shows the modification of the linear structure of FIG. It is a figure which shows the modification of the linear structure of FIG. FIG. 96 is a cross-sectional view through a liquid crystal display device having the linear structure of FIG. 95. It is a figure which shows the modification of the linear structure of FIG. It is a figure which shows the modification of the linear structure of FIG. It is a figure which shows the linear structure of the liquid crystal display device by 9th Example of this invention. It is a figure which shows the modification of the linear structure of FIG. It is a figure for demonstrating the problem of finger pressing in the liquid crystal display device which has a linear structure. It is a figure which shows the example which is easy to produce the problem of finger pressing. FIG. 100 is a diagram showing an example of a means for forming the first type boundary of FIG. 99. FIG. 104 is an illustrative perspective view showing a liquid crystal display device having means for forming the first type boundary of FIG. 103. FIG. 99 is a diagram showing an example of means for forming the second type boundary of FIG. 99. FIG. 106 is a schematic perspective view showing a liquid crystal display device having means for forming the second type boundary of FIG. 105. FIG. 100 is a diagram showing an example of a means for forming the first type boundary of FIG. 99. FIG. 99 is a diagram showing an example of means for forming the second type boundary of FIG. 99. It is a figure which shows the linear structure of the liquid crystal display device by 10th Example of this invention. FIG. 110 is a cross-sectional view taken along line 110-110 of the liquid crystal display device of FIG. 109. It is a figure which shows the modification of the liquid crystal display device of FIG. It is a figure which shows the modification of the liquid crystal display device of FIG. FIG. 113 is a cross-sectional view of the liquid crystal display device of FIG. 112 taken along line 113-113. It is a figure which shows the modification of the liquid crystal display device of FIG. FIG. 115 is a cross-sectional view of the liquid crystal display device of FIG. 114 taken along line 115-115. It is a figure which shows the manufacturing method of the board | substrate which has a linear structure and a subwall structure. It is a figure which shows the other example of the manufacturing method of the board | substrate which has a linear structure and a subwall structure. FIG. 111 is a diagram showing responsiveness in the liquid crystal display device of FIG. 111 when the width of the sub-wall structure (slit) is constant and the interval of the sub-wall structure (slit) is changed. FIG. 111 is a diagram showing responsiveness when the width of the sub-wall structure (slit) is changed while the interval of the sub-wall structure (slit) is made constant in the liquid crystal display device of FIG. FIG. 113 is a diagram showing responsiveness in the liquid crystal display device of FIG. 112 when the size of the sub-wall structure (projection) is constant and the interval between the sub-wall structures (projections) is changed. FIG. 113 is a diagram illustrating responsiveness when the size of the sub-wall structure (projection) is changed while the interval between the sub-wall structures (projections) is constant in the liquid crystal display device of FIG. It is a figure which shows the linear structure of the liquid crystal display device by 10th Example of this invention. It is a figure which shows the modification of the liquid crystal display device of FIG. It is a figure which shows the manufacturing method of the liquid crystal display device of FIG. It is a figure which shows the manufacturing method of the liquid crystal display device of FIG. It is a figure which shows the modification of the liquid crystal display device of FIG. It is a figure which shows the modification of the liquid crystal display device of FIG. It is a figure which shows the modification of the liquid crystal display device of FIG. It is a figure which shows the modification of the liquid crystal display device of FIG. It is a figure which shows the modification of the liquid crystal display device of FIG. It is a figure which shows the modification of the liquid crystal display device of FIG. It is a figure which shows the modification of the liquid crystal display device of FIG. It is a figure which shows the modification of the liquid crystal display device of FIG. It is a figure which shows the modification of the liquid crystal display device of FIG. It is a figure which shows the modification of the linear alignment control structure of FIG. It is a figure which shows the modification of the linear alignment control structure of FIG. It is a figure which shows the modification of the linear alignment control structure of FIG. It is a figure which shows the modification of the linear alignment control structure of FIG. It is a figure which shows the modification of the linear alignment control structure of FIG. It is a figure which shows the modification of the linear alignment control structure of FIG. It is a figure which shows the modification of the linear alignment control structure of FIG. It is a figure which shows the modification of the linear alignment control structure of FIG. It is a figure which shows the modification of the linear alignment control structure of FIG. It is a figure which shows the modification of the linear alignment control structure of FIG. It is a figure which shows the modification of the linear alignment control structure of FIG. It is a figure which shows the modification of the linear alignment control structure of FIG. It is a figure which shows the modification of the linear alignment control structure of FIG. It is a figure which shows the modification of the linear alignment control structure of FIG. It is a figure which shows the modification of the linear alignment control structure of FIG. It is a figure which shows the modification of the linear alignment control structure of FIG. It is a figure which shows the modification of the linear alignment control structure of FIG. It is a figure which shows the modification of the linear alignment control structure of FIG. It is a figure which shows the modification of the linear alignment control structure of FIG. It is a figure which shows the modification of the linear alignment control structure of FIG. It is a figure which shows the modification of the linear alignment control structure of FIG. It is a figure which shows the modification of the linear alignment control structure of FIG. It is a figure which shows the modification of the linear alignment control structure of FIG.

Explanation of symbols

12, 14 Substrate 16 Liquid crystal 18, 22 Electrode 20, 24 Vertical alignment film 26, 28 Polarizing plate 30, 32 Linear structure (protrusion)
30S, 32S constitutional unit 42 oblique electric field 44, 46 linear structure (slit structure)
44S, 46S constitutional unit

Claims (11)

A liquid crystal display device having a plurality of pixels,
A first substrate, a second substrate provided opposite to the first substrate, and a liquid crystal layer disposed between the first substrate and the second substrate,
The first substrate includes a linear first structure, a second structure, and an auxiliary structure that control alignment of liquid crystal,
The second substrate includes a linear third structure and a fourth structure that control alignment of liquid crystal,
The first structure, the second structure, and the auxiliary structure extend in different directions in one pixel,
The third structure extends in the pixel in parallel with the first structure, and the fourth structure extends in parallel with the second structure.
The first structure, the second structure, the third structure, and the fourth structure are all liquid crystal display devices that extend in a direction different from the direction in which the edge of the pixel extends . The liquid crystal display device according to claim 1, wherein the first structure body and the second structure body are continuously formed via a bent portion . The liquid crystal display device according to claim 2, wherein the auxiliary structure extends to an obtuse angle side of the bent portion . The liquid crystal display device according to claim 3, wherein the auxiliary structure extends in a direction that bisects an angle between a direction in which the first structure extends and a direction in which the second structure extends . The liquid crystal display device according to claim 2 , wherein the auxiliary structure extends to an acute angle side of the bent portion . 6. The liquid crystal display device according to claim 5 , wherein the auxiliary structure extends in a direction that bisects an angle between a direction in which the first structure extends and a direction in which the second structure extends . The first substrate has a common electrode;
The liquid crystal according to any one of claims 1 to 6, wherein the first structure and the second structure are protrusions formed on the common electrode or slits formed on the common electrode. Display device. It said auxiliary structure, protrusions formed on the common electrode, or a slit formed in the common electrode, the liquid crystal display device according to claim 7. The said 2nd board | substrate is a structure which controls the orientation of a liquid crystal, Comprising: The any one of Claim 1 to 8 which has the 2nd auxiliary | assistant structure extended in a different direction from the said 3rd structure and the said 4th structure. 2. A liquid crystal display device according to item 1 . The second substrate includes a pixel electrode, and the third structure, the fourth structure, and the second auxiliary structure are formed on a protrusion formed on the pixel electrode or the pixel electrode. The liquid crystal display device according to claim 9, wherein the liquid crystal display device is a slit . The liquid crystal display device according to claim 1, wherein an angle between a direction in which the first structure extends and a direction in which the second structure extends is about 90 ° .

Images