JP3834304B2 - Liquid crystal display element - Google Patents

Description

  The present invention particularly relates to a liquid crystal display element having improved viewing angle characteristics.

  In order to improve the viewing angle characteristics of the liquid crystal display element, it is effective to provide slits in the electrodes. A TN-LCD has been specifically proposed (see, for example, Patent Document 1), and has also been proposed for a vertical alignment LCD (Japanese Patent Application No. 2003-044262 (2003.2.21)). . Among these, the feature of the slit arrangement and the role of the slit are shown as follows.

  A pair of substrates disposed opposite to each other, a pair of transparent electrodes provided on the pair of substrates and overlapping each other with a liquid crystal layer interposed therebetween, and transparent in the display region of each of the pair of transparent electrodes A rectangular slit from which a part of the electrode is removed, and the slit of one transparent electrode of the pair of transparent electrodes and the slit of the other transparent electrode are orthogonal to the slit longitudinal direction in the display region Are alternately arranged in the direction of

  By providing the slit in the display region, an oblique electric field (an electric field whose direction is inclined from the normal direction of the substrate) is generated near the edge of the slit when a voltage is applied, and the direction in which the liquid crystal molecules fall can be controlled. . Moreover, since the slits are alternately arranged between the pair of transparent electrodes, the directions of the oblique electric fields at both ends of each display region surrounded by the slits are the same direction (parallel to each other). The direction of the oblique electric field is reversed between the display areas divided by the adjacent slits. This is illustrated in FIG.

  FIG. 10 is a cross-sectional view showing a state of the oblique electric field in the display region as described above, and shows a cross-sectional shape when the liquid crystal display element is cut at right angles to the longitudinal direction of the slit. In the figure, reference numerals 1 and 2 denote slits provided in the transparent electrodes 3 and 4 of the upper and lower substrates, and an oblique electric field 5 is generated due to a shift in the vertical position.

  With respect to the oblique electric field 5, the vertically aligned liquid crystal molecules are tilted in the direction as shown in FIG. 11, so that the slit structure as described above makes the regions formed by the slits 1 and 2 adjacent to each other. The liquid crystal molecules 6 in the region fall down in the opposite direction. A so-called two-domain alignment structure can be realized. In principle, the TN-LCD is exactly the same as this, except that the horizontally aligned liquid crystal molecules rise from two directions instead of falling down.

  And the concrete slit shape is shown as an Example in each. In the case of the TN-LCD disclosed in Patent Document 1, as shown in FIG. 12, one elongated slit connected from end to end of the display area is alternately arranged on the upper and lower substrates in a direction perpendicular to the longitudinal direction of the slit. . (A) of the figure is a plan view, (b) is a perspective view, 1a, 1b, 1c are slits of the upper substrate, 2a, 2b, 2c are slits of the lower substrate, 7 is the orientation direction of the upper substrate, Reference numeral 8 denotes the orientation direction of the lower substrate, and 9 denotes the orientation direction of the liquid crystal molecules at the center of the liquid crystal layer.

  In the case of a vertical alignment LCD, as shown in FIG. 13, slits having a large number of slit longitudinal directions are alternately arranged on the upper and lower substrates in a direction perpendicular to the slit longitudinal direction. (A) of the same figure is a top view, (b) is a perspective view.

  When using one long and narrow slit like the former, it is necessary to connect the area divided by the slit outside the display area (see FIG. 12). Although this is possible in terms of design, the design process becomes complicated, leading to an increase in cost, and the overlay accuracy of the upper and lower electrode patterns becomes severe.

  On the other hand, in the latter example, since the slit is divided and the area divided by the slit is connected in the display area, it is not necessary to connect them outside the display area, and the pattern design is simplified. . However, display defects are easily caused by using the slits divided in the longitudinal direction in this way.

  FIG. 14 is a diagram (photograph) showing an example of display failure of a two-domain TN-LCD manufactured using the latter slit. This two-domain TN-LCD uses a low pretilt angle alignment film and reverses the rubbing direction of one side of the substrate from the normal direction, so that the liquid crystal molecules are splay aligned with respect to the cell thickness direction. By making the tilt angle of the liquid crystal molecules 0 degree, the device is devised so that two-domain alignment can be stably obtained.

  It can be seen that in the portion surrounded by a circle in the figure, the disclination line originally connecting the adjacent slits in the longitudinal direction connects the adjacent slits in the short direction. In the region surrounded by the two disclination lines connecting the short slit direction, the liquid crystal molecules rise from the direction opposite to the direction that should originally rise. Accordingly, the viewing angle direction is reversed in this region, and a large number of such regions cause display defects. Specifically, the display appears rough when the viewing angle is tilted in the slit short direction. Further, it has been found that this display defect becomes prominent when the liquid crystal cell is continuously displayed in a high temperature atmosphere.

  FIG. 15 is an enlarged view (photograph) of the display area after the display is continued at 85 ° C. for about 500 hours. It can be seen that the area surrounded by the two disclination lines connecting the slit short direction seen earlier appears over a wide range. When this cell was visually observed, it was very difficult to see. The cause of such a display failure will be considered with reference to FIG.

  FIG. 16 is a diagram showing the alignment state of the liquid crystal molecules having the above-mentioned poor display, and schematically shows the alignment state of the liquid crystal molecules in the AA ′ cross section of FIG. As shown in the figure, A-A 'is originally a two-domain alignment of region 1 (molecules rise from the right direction) and region 2 (molecules rise from the left direction), as shown in the figure. The disclination line (disclination line connecting the longitudinal direction of the slits) is formed around the portion where the pretilt angle θ of the liquid crystal molecules 6 in the center of the cell is 0 degree, while the orientation is continuously changed.

Originally, the pretilt angles of the upper and lower substrates are equal, so that the splay alignment is symmetric with respect to the liquid crystal molecules at the center of the cell where the pretilt angle is 0 degree. For this reason, the free energy due to the elastic deformation of the liquid crystal molecules in the region 1 and the region 2 is equal, and the balance between the two regions is maintained, so that the disclination line is stable without moving over time. However, when the pretilt angles of the upper and lower substrates are different due to a slight shift in the rubbing conditions (in FIG. 16, the pretilt angle of the upper substrate is large and θ ₁ > θ ₂ ), the free energy of both regions is The region where the pretilt angle is not equal and the region where the pretilt angle rises (region 2) has a lower free energy and is more stable than the opposite region (region 1).

  In such a state, the liquid crystal molecular alignment changes to a more stable state, so that the movement of the disclination line occurs as shown by the arrow in FIG. 16, and the region 1 gradually decreases with time. Eventually, the area 2 will be filled up. Since the difference in the pretilt angle between the upper and lower substrates is very small because a low pretilt alignment film is used, the difference in free energy between region 1 and region 2 is small, and such movement of the disclination line should not occur at room temperature. Considering that, at high temperatures, the elastic constants of the liquid crystal molecules become smaller and the fluctuations of the liquid crystal molecules also become larger. Therefore, such movement of the disclination line occurs, leading to a display defect as shown in FIG. It is thought that it will end up.

The reason why the display failure as shown in FIG. 14 occurs at normal temperature and immediately after the voltage is applied is that the difference in the pretilt angle between the upper and lower substrates in this part is large and the difference in free energy between the two regions shown in FIG. In addition, it is considered that the disclination line moves immediately after the voltage application, or that the pretilt angle difference is so large that this region rises from the opposite direction from the beginning.
Japanese Patent No. 3108768

  As described above, the viewing angle characteristics can be improved by providing slits on the electrodes of the upper and lower substrates of the liquid crystal display element, but this may lead to complicated design and cost increase, and the assembly accuracy may become severe. . In addition, display defects may occur, and a rough feeling or a difficult-to-see feeling may occur.

  The present invention has been made in view of the occurrence of the above problems, and can prevent the design from becoming complicated and costly, and the occurrence of display defects, so that even when the viewing angle is tilted, the user feels a rough display. The present invention aims to provide a liquid crystal display element that can provide good viewing angle characteristics.

The liquid crystal display element according to the present invention is a liquid crystal display element in which a liquid crystal is sandwiched between a pair of substrates having a transparent electrode on which a predetermined pattern is formed for display, and the transparent electrodes on the pair of substrates In the region where the two electrodes are opposed to each other, both the transparent electrodes of the pair of substrates have a slit partially removed in a rectangular shape, and the slit provided on the transparent electrode on one substrate and the other transparent electrode And the slits provided in one of the transparent electrodes are alternately arranged in the direction perpendicular to the longitudinal direction of the slits in the region facing each other, and the other side of the slits provided in one of the transparent electrodes The short side of the slit provided in is arranged at a position that is not lined up in a direction perpendicular to the longitudinal direction of the slit and at a position shifted by about a half pitch with respect to the longitudinal direction of the slit. You It is intended.

  According to the present invention, it is possible to prevent the design from becoming complicated and costly, and to prevent the occurrence of display defects. Even when the viewing angle is tilted, there is an effect that a favorable viewing angle characteristic can be obtained without feeling a rough display.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, Example 1 of the present invention will be described in detail while comparing with Reference Example 1. In Reference Example 1 and Example 1, a case where the present invention is applied to a two-domain TN-LCD for segment display will be described.

(Reference Example 1)
The display area has a slit from which a part of the transparent electrode is removed, and the slit of one transparent electrode and the slit of the other transparent electrode of the pair of transparent electrodes arranged opposite to each other are within the display area. A low pretilt angle alignment film (SE-510 manufactured by Nissan Chemical Industries, Ltd.) is applied and baked on a substrate having a predetermined pattern alternately arranged in a direction perpendicular to the longitudinal direction. After that, the substrate is rubbed with a rayon rubbing cloth so as to have the relationship shown in FIG. The twist direction of the liquid crystal is left-handed.

  FIG. 1 is a diagram showing a slit pattern in a state where the above-mentioned cell is formed, wherein 1 is a slit of the upper substrate, and 2 is a slit of the lower substrate. The dimensions of the slits 1 and 2 are 20 μm × 100 μm, and the upper and lower slits are 20 μm in the length direction and 40 μm in the direction perpendicular thereto. FIG. 2 is a diagram showing the rubbing direction in the state of being a cell. The rubbing direction of the upper substrate and the rubbing direction of the lower substrate are orthogonal to each other.

  By setting the rubbing direction as shown in FIG. 2, the liquid crystal molecules are splay aligned, and the tilt angle of the liquid crystal molecules at the center of the cell is 0 degree. The main sealing material is applied to the two substrates thus produced, and a gap control material having a diameter of 9 μm is further dispersed. Thereafter, the main seal material is cured by overlapping. Then, a liquid crystal cell having a birefringence of 0.25 manufactured by Dainippon Ink Co., Ltd. is injected into the completed empty cell to complete the liquid crystal cell. A polarizing plate is bonded to the liquid crystal cell with a structure as shown in FIG. In this way, a normally black display 2-domain TN-LCD can be manufactured.

  FIG. 3 is a diagram showing the absorption axis of the polarizing plate, and the absorption axis of the polarizing plate on the front side (upper side) and the absorption axis of the polarizing plate on the back side (lower side) are parallel.

  When a voltage was applied to the above cell for display, display defects as shown in FIG. 14 occurred in many parts, and the display looked rough when the liquid crystal cell was viewed from an oblique direction. In the area surrounded by the two disclination lines that connect the slit short direction, the liquid crystal molecules are rising from the direction opposite to the direction where they should stand up. In this area, the viewing angle direction is reversed. is there.

  Further, when the cell was continuously energized in an atmosphere of 85 ° C., a display defect as shown in FIG. 15 occurred after about 500 hours had elapsed, and the display became extremely difficult to see. However, this display defect seems to be solved by lowering the voltage once to return the liquid crystal molecules to the initial alignment state. Even if the voltage is increased again, the display is not so difficult to see. When the voltage was once reduced and the cell with the display defect eliminated was energized again in an atmosphere of 85 ° C., a similar display defect that was difficult to see occurred after 60 hours.

[Example 1]
The display area has a slit from which a part of the transparent electrode is removed, and the slit of one transparent electrode and the slit of the other transparent electrode of the pair of transparent electrodes arranged opposite to each other are within the display area. In a state where the slits provided in the other transparent electrode are shifted by a half pitch with respect to the slit provided in the other transparent electrode with respect to the slit provided in one transparent electrode alternately with the direction perpendicular to the longitudinal direction. An alignment film having a low pretilt angle (SE-510, manufactured by Nissan Chemical Industries, Ltd.) is applied and baked on the substrate having a predetermined pattern. Thereafter, the substrate is rubbed using a rayon rubbing cloth so that the relationship shown in FIG. 2 (the rubbing direction in the cell state is shown) is obtained. The twist direction of the liquid crystal is left-handed.

  FIG. 4 is a diagram showing the slit pattern of this embodiment in the state of a cell, and the dimensions and the distance in the length direction of the slit 1 of the upper substrate and the slit 2 of the lower substrate are the same as those in FIG. The slits 1 and 2 are shifted by a half pitch in the length direction. The interval in the direction orthogonal to the length direction is the same as in FIG.

  By setting the rubbing direction as shown in FIG. 2, the liquid crystal molecules are splay aligned, and the tilt angle of the liquid crystal molecules at the center of the cell is 0 degree. The main sealing material is applied to the two substrates thus produced, and a gap control material having a diameter of 9 μm is further dispersed. Thereafter, the main seal material is cured by overlapping. A liquid crystal cell is completed by injecting a liquid crystal having a birefringence of 0.25 manufactured by Dainippon Ink Co., Ltd. A polarizing plate is bonded to the liquid crystal cell with a structure as shown in FIG. In this way, a normally black display 2-domain TN-LCD can be manufactured.

  When this cell is displayed by applying a voltage, it is as shown in FIG. 5, and there is no display defect due to the occurrence of a disclination line connecting the adjacent slits in the slit short direction as seen in FIG. A display that does not occur can be realized, and even when the cell is viewed from an oblique direction, no roughness is felt. Further, when this cell was continuously energized in an atmosphere of 85 ° C., the display state remained clean even after 1000 hours had elapsed, and no problem occurred.

  The slit size will be explained. When the slit width (length in the direction perpendicular to the longitudinal direction) is more than a certain level, the electric field at the center of the slit becomes extremely weak, and the liquid crystal molecules react to voltage application. An area that disappears occurs, and a display defect occurs in that area. Further, the area other than the slit, that is, the area of the liquid crystal molecules responding to the electric field is reduced, and the so-called aperture ratio is reduced, so that the transmittance during voltage application is reduced. Considering this, the width of the slit is preferably 30 μm or less. On the other hand, if the slit width is too narrow, a sufficient oblique electric field is not generated, and the effect of the present invention cannot be sufficiently exhibited.

  According to an experiment conducted with various slit widths, it was found that when the slit width was 5 μm, a beautiful two-domain orientation was not obtained. In such a case, when the cell is visually observed, a feeling of display roughness due to domain instability is felt particularly from the direction in which the viewing angle is inclined. It was found that when the slit width is 10 μm, the liquid crystal molecules are somewhat unstable in the direction of tilting, but the rough feeling when the viewing angle is tilted is also acceptable. On the other hand, when the slit width was 20 μm, it became clear that the two-domain orientation was clean and stable, and even when the viewing angle was tilted, it did not feel rough.

  In addition, the gap between the upper and lower electrodes in the slit short direction between adjacent slits is preferably large in order to ensure a sufficient display area, but in order to ensure the stability of two domains, two domains are visually observed. In order to prevent the pattern from being identified, it is preferable that the pattern is as narrow as possible. When experiments were performed with various intervals, it was found that if the interval between the slits was 70 μm, the stability of the two domains could not be obtained, and at least 60 μm or less was preferable in terms of the stability of the two domains. It was. Moreover, if it was 60 micrometers or less, the pattern of 2 domains was not identified visually. Further, the minimum value of this interval is preferably as wide as possible in view of the aperture ratio. Therefore, at least 10 μm or more than the width of the slit is desirable.

  Further, regarding the length of the slit, since the display defect shown in FIG. 14 occurs starting from the slit edge, it is preferable to make the slit as long as possible to reduce the number of edge portions. The longer the length, the smaller the area of the transparent electrode that connects the adjacent areas in the lateral direction of the slit, and there is a disadvantage that display unevenness occurs due to an increase in the resistance value of that portion. As a result of experiments on slits having various lengths, it was found that a slit having a length of about 20 μm to 300 μm is suitable. Furthermore, it was also found that the width of the transparent electrode connecting the adjacent regions in the slit short direction (20 μm in FIG. 4) is suitably about 10 μm to 50 μm.

  Finally, how to displace the slits provided on the upper and lower substrates in the slit longitudinal direction will be described. In the present embodiment, the case is shown in which only half of the repetitive dimension in the slit longitudinal direction is shifted, but it is not limited to this, and the same effect can be obtained if the slits of the upper and lower substrates are shifted even a little. Conceivable. However, from the viewpoint of symmetry, it can be considered that the case where it is shifted by a half pitch is symmetrical and is most stable.

  Next, Example 2 of the present invention will be described in detail in comparison with Reference Example 2. In Reference Example 2 and Example 2, the case where the present invention is applied to a two-domain vertical alignment type LCD for segment display will be described.

(Reference Example 2)
As in Reference Example 1, the display area has a slit from which a part of the transparent electrode has been removed, and the slit of one transparent electrode and the slit of the other transparent electrode of the pair of opposed transparent electrodes are A vertical alignment film (SE-1211 manufactured by Nissan Chemical Industries, Ltd.) is applied and baked on a substrate having a predetermined pattern (slit pattern and dimensions are the same as in Conventional Example 1; see FIG. 1) alternately arranged in the display area. To do. The main sealing material is applied to the two substrates thus produced, and a gap control material having a diameter of 4 μm is further dispersed. Thereafter, the main seal material is cured by overlapping. A liquid crystal cell having a birefringence of 0.15 manufactured by Merck is injected into the completed empty cell to complete the liquid crystal cell. A viewing angle compensator (VAC-180 film manufactured by Sumitomo Chemical Co., Ltd.) and a polarizing plate are bonded to the liquid crystal cell with a structure as shown in FIG. In this way, a two-domain vertical alignment type LCD can be manufactured.

  When a voltage was applied to the cell for display, the liquid crystal cell looked rough when viewed from an oblique direction. Further, when this cell was continuously energized in an atmosphere of 85 ° C., the display defect as seen in the 2-domain TN-LCD did not occur.

[Example 2]
The display area has a slit from which a part of the transparent electrode is removed, and the slit of one transparent electrode and the slit of the other transparent electrode of the pair of transparent electrodes arranged opposite to each other are within the display area. In a state where the slits provided in the other transparent electrode are shifted by a half pitch with respect to the slit provided in the other transparent electrode with respect to the slit provided in one transparent electrode alternately with the direction perpendicular to the longitudinal direction. A vertical alignment film (SE-1211 manufactured by Nissan Chemical Industries, Ltd.) is applied and baked on a substrate having a predetermined pattern (see FIG. 4 for the slit pattern and dimensions in a cell state). The main sealing material is applied to the two substrates thus produced, and a gap control material having a diameter of 4 μm is further dispersed. Thereafter, the main seal material is cured by overlapping. A liquid crystal cell having a birefringence of 0.15 manufactured by Merck is injected into the completed empty cell to complete the liquid crystal cell. A viewing angle compensator (VAC-180 film manufactured by Sumitomo Chemical Co., Ltd.) and a polarizing plate are bonded to the liquid crystal cell with a structure as shown in FIG. In this way, a two-domain vertical alignment type LCD can be manufactured.

  6A and 6B are diagrams showing the cell structure. FIG. 6A is a cross-sectional view thereof, and FIG. 6B is an absorption axis of the polarizing plate. In the figure, 11 and 12 are upper and lower polarizing plates, 13 is a viewing angle compensation film, and 14 is a vertical alignment type LCD. The absorption axis of the polarizing plate 11 on the front side (upper side) and the absorption axis of the polarizing plate 12 on the back side (lower side) are orthogonal to each other.

  When a voltage was applied to the above cell for display, no display roughness was observed even when the liquid crystal cell was viewed from an oblique direction. Furthermore, even when the cell was continuously energized in an atmosphere of 85 ° C., the display defect as seen in the 2-domain TN-LCD of Reference Example 1 did not occur.

Example 3
Next, a case where the present invention is applied to a dot matrix type two-domain TN-LCD and a two-domain vertical alignment type LCD will be described.

  Similarly to the segment display, the slit is not shifted in the longitudinal direction (see FIG. 7) and the slit is shifted in the longitudinal direction by a half pitch (see FIG. 8). Further, when a 2-domain vertical alignment type LCD was fabricated and the roughness of the display was confirmed, the display roughness could be greatly reduced by making the structure shifted by a half pitch.

  FIG. 7 shows a structure in which the slit 1 of the segment substrate and the slit 2 of the common substrate are not shifted in the longitudinal direction, and FIG. 8 is a diagram showing a structure in which the slits 1 and 2 are shifted by a half pitch in the longitudinal direction. In the figure, 15 indicates a segment substrate (upper substrate), and 16 indicates a common substrate.

  In the case of dot matrix display, slits are laid only in the intersecting portions of the horizontal comb-shaped electrode (common electrode) and the vertical comb-shaped electrode (segment electrode). As in the segment display, the slits are alternately arranged between the upper and lower electrodes in the display area. Accordingly, the rising direction (in the case of TN) of the liquid crystal molecules and the direction of falling (in the case of the vertical alignment type) are alternately reversed, so that a two-domain structure is formed, and the liquid crystal molecules when an electric field is applied to a small region sandwiched between slits in the display region. Since the inclination of the rotation is alternately reversed, the viewing angle characteristics are complemented as a whole, and the viewing angle dependency is reduced, so that visibility is improved from any direction.

  Further, the preferred values of the slit width, the interval between adjacent slits between the upper and lower electrodes, and the length of the slit were the same as those in the segment display described in the first embodiment.

  It should be noted here that the electrode at the extreme end in the direction orthogonal to the longitudinal direction of the slit of one dot, that is, the slit at the extreme end (both ends) is arranged orthogonal to the longitudinal direction of the slit. (Segment electrodes in FIGS. 7 and 8) are provided on the side.

Example 4
Next, the case where the present invention is applied to a TFT active matrix type liquid crystal display element will be described.

  FIG. 9 is a plan view showing several pixel regions of a TFT active matrix liquid crystal display device. The active matrix type liquid crystal device is generally used at present, and the structure thereof is only briefly described. In the figure, a plurality of TFT elements 20 made of amorphous silicon, a transparent pixel electrode 21 made of ITO, etc., and a source electrode S and a gate electrode G of the TFT element 20 are respectively formed on a transparent glass substrate (not shown). A source line (signal line) 22 and a gate line (scanning line) 23 to be connected are formed, and the pixel element 21 is driven by the TFT element 20 via the drain electrode D. Although not shown, a vertical alignment film (in the case of a vertical alignment type) or a horizontal alignment film that has been subjected to a rubbing process (in the case of TN) is formed on the pixel electrode 21.

  Although not shown in the plan view, the description is omitted, but another glass substrate is disposed on the glass substrate on which the pixel electrode is formed so as to face the substrate with a liquid crystal layer interposed therebetween. A common electrode is formed. Also, a vertical alignment film (in the case of a vertical alignment type) or a film obtained by subjecting a horizontal alignment film to a rubbing process (in the case of TN) is formed on the surface of the common electrode that is in contact with the liquid crystal layer.

  The pixel electrode 21 is formed with a plurality of slits 24 shown by solid lines as shown in the drawing, with a part of the electrode removed. Further, the common electrode facing the pixel electrode 21 is also formed with a slit 25 from which a part of the electrode as shown by a broken line is deleted. The slits 24 and 25 of the upper and lower substrates are alternately arranged, and the slits provided in the common electrode are arranged in a state shifted by a half pitch with respect to the slit longitudinal direction with respect to the slits provided in the pixel electrode.

  The cross section in the direction orthogonal to the longitudinal direction of the slit in FIG. 9 basically corresponds to the cross sectional structure shown in FIG. The slits 24 and 25 arranged alternately between the upper and lower electrodes produce the same effects as described in the first and second embodiments.

  It should be noted here that, similarly to the dot matrix type liquid crystal display element of the second embodiment, the slit at the extreme end (both ends) in the direction orthogonal to the longitudinal direction of the slit of one pixel electrode 61 is It is to be provided on the common electrode side.

  As described above, each embodiment of the present invention has been described. By adopting the structure of the embodiment, it is possible to prevent design complexity and cost increase, and display defects, and display roughness even when the viewing angle is tilted. It is possible to realize a liquid crystal display element capable of obtaining good viewing angle characteristics without feeling the above.

  The active matrix structure includes other structures other than those described above, but the present invention can also be applied to such other active matrix structures. The present invention is not limited to the embodiments described above with reference to the drawings, and it goes without saying that various modifications and improvements can be made by those skilled in the art based on the above disclosure. Even in such a case, display roughness can be suppressed by adopting a structure shifted by a half pitch.

  The present invention is applicable to both liquid crystal display elements of segment display and dot matrix display. Furthermore, the present invention can also be applied to an active matrix type liquid crystal display element using a switching element such as a TFT.

Explanatory drawing which shows the slit pattern of the reference example 1. The figure which shows the rubbing direction of an Example The figure which shows the absorption axis of the polarizing plate of an Example Explanatory drawing which shows the slit pattern of Example 1. Figure showing a display example of Example 1 (photo) The figure which shows the cell structure of the reference example 2 Plan view showing a structure in which the slit is not displaced in the longitudinal direction Plan view showing a structure in which the slit is shifted by a half pitch in the longitudinal direction Plan view showing a pixel region of a TFT active matrix liquid crystal element Sectional view showing the state of the oblique electric field in the display area Explanatory drawing showing the state of liquid crystal molecules by an oblique electric field The figure which shows the slit shape of a prior art example The figure which shows the slit shape of another prior art example Figure showing an example of display failure (photo) Figure showing enlarged examples of display defects (photo) Explanatory drawing showing the orientation of liquid crystal molecules with poor display

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Upper substrate slit 2 Lower substrate slit 3 Transparent electrode 4 Transparent electrode 5 Diagonal electric field 6 Liquid crystal molecule 11 Polarizing plate 12 Polarizing plate 13 Viewing angle compensation film 14 Vertical alignment type LCD
15 Upper substrate 16 Lower substrate 20 TFT element 21 Transparent pixel electrode 24 Slit 25 Slit

Claims (13)

A liquid crystal display element in which a liquid crystal is sandwiched between a pair of substrates having a transparent electrode on which a predetermined pattern is formed for display, in the region where the transparent electrodes on the pair of substrates are opposed to each other, The transparent electrode of both of the pair of substrates has a slit partially removed in a rectangular shape, and the slit provided in the transparent electrode on one substrate and the slit provided in the other transparent electrode In the region facing each other, they are alternately arranged in a direction orthogonal to the longitudinal direction of the slit, and the short side of the slit provided in one transparent electrode and the short side of the slit provided in the other transparent electrode, However, the liquid crystal display element is arranged at a position that is not aligned in a direction perpendicular to the longitudinal direction of the slit and is displaced by a half pitch with respect to the longitudinal direction of the slit. The liquid crystal display element according to claim 1, wherein a slit width in a direction orthogonal to the longitudinal direction of the slit is 10 μm or more and 30 μm or less. The liquid crystal display element according to claim 1, wherein an interval between adjacent slits of the alternately arranged slits is 10 μm or more and 60 μm or less. The liquid crystal display element according to claim 1, wherein an interval between adjacent slits of the alternately arranged slits is not less than the width of the slit and not more than 60 μm. 5. The liquid crystal display element according to claim 1, wherein the display by the liquid crystal is a segment type display. 5. The liquid crystal display element according to claim 1, wherein the display by the liquid crystal is a dot matrix type display. 5. The liquid crystal display element according to claim 1, wherein the liquid crystal display is a display having both a segment type display and a dot matrix type display. 8. The liquid crystal display element according to claim 6, wherein the dot matrix type display is a display by simple matrix driving. The liquid crystal display element according to claim 6, wherein the dot matrix type display is display by active matrix driving. In the dot matrix type display, the slit at the endmost portion in the direction orthogonal to the longitudinal direction of the slit of one dot is provided on the electrode side arranged orthogonal to the longitudinal direction of the slit. The liquid crystal display element according to claim 6. 10. The liquid crystal display element according to claim 9, wherein a slit at the endmost portion in a direction orthogonal to the longitudinal direction of the slit of one pixel electrode for display by the active matrix driving is provided on the common electrode side. The liquid crystal display element according to claim 1, wherein the liquid crystal is a TN liquid crystal. The liquid crystal display element according to claim 1, wherein the liquid crystal is a vertical alignment type liquid crystal.