JP2010256738A - Liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device capable of achieving monodomain alignment with arbitrary size at an arbitrary position even without performing direct alignment treatment to the substrate surface. <P>SOLUTION: The liquid crystal display device 1 includes: a first substrate 11 which has a first electrode 12 on one surface side; a second substrate 15 which has a second electrode 16 on one surface side, and is arranged opposite to the first substrate 1 so that the second electrode faces the first electrode of the first substrate; and a liquid crystal layer 14 which is provided between the first and second substrates. The first electrode has a plurality of first openings 18 each of which is provided in the rectangular shape, and the second electrode has a plurality of second openings 19 each of which is provided in the rectangular shape. Each first opening is arranged so that at least part of each first side overlaps any one or more of the second openings in a planar view, and a second side which faces the first side overlaps none of the second openings and faces the second electrode in a planar view. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a technique for controlling alignment of liquid crystal molecules in a liquid crystal display device.

  Liquid crystal display devices are widely used as information display units in, for example, various consumer and in-vehicle electronic devices. In such a liquid crystal display device, it is one of important elemental technologies to appropriately control the orientation direction of liquid crystal molecules in order to obtain a favorable viewing angle characteristic according to the application. As a typical technique for controlling the orientation direction of liquid crystal molecules, a rubbing method, a photo-alignment method, and the like are known. The rubbing method is a technique in which an alignment film made of an organic material such as polyimide is formed on the surface of a substrate, and then this alignment film is mechanically rubbed with a rubbing cloth (for example, see Patent Document 1). The photo-alignment method is a method in which an alignment film made of an organic material such as polyimide is formed on the substrate surface, and then the alignment film is irradiated with ultraviolet rays from an oblique direction with respect to the substrate normal (for example, Patent Documents). 2). By using an alignment film formed on the substrate by these methods, the alignment direction of the liquid crystal molecules can be controlled to one certain direction. That is, monodomain orientation can be realized.

  By the way, depending on the use of the liquid crystal display device and the like, there are cases where it is desired to form a monodomain alignment of an arbitrary size at an arbitrary position. This can be realized by applying the rubbing method or the photo-alignment method described above. Specifically, when the rubbing method is used, when rubbing a region corresponding to a certain alignment domain in the alignment film on the substrate, a region corresponding to another alignment domain is used with a photoresist or a metal mask. A method of covering in advance and preventing the region from being rubbed is known (for example, Patent Document 3). In the case of using the photo-alignment method, in the alignment film on the substrate, when irradiating the region corresponding to a certain alignment domain, the region corresponding to the other alignment domain is shielded with a photomask. Therefore, there is known a method for preventing the region from being irradiated with light (Patent Document 4). According to these methods, for example, in a segment type liquid crystal display device, an alignment domain is arbitrarily set with each segment display unit as a unit, or in a dot matrix type liquid crystal display device, two alignment domains are set for one pixel. The orientation domain can be freely controlled.

  However, each of the above conventional alignment control techniques has disadvantages. When the rubbing method is used, streak-like alignment unevenness tends to occur due to mechanical rubbing of the alignment film. This tendency is particularly noticeable when a vertical alignment film is used. For this reason, it becomes necessary to selectively use an alignment film having a specific surface free energy, or high precision is required due to the setting of the rubbing treatment conditions. Become. In addition, when using the photo-alignment method, only a specific alignment film material suitable for this method can be selected, and the tact time becomes longer due to the longer light irradiation time. There is an inconvenience that it is difficult to apply. Further, in the case of using either the rubbing method or the light irradiation method, there is a disadvantage that the number of steps increases according to the number of orientation domains to be set.

  On the other hand, a technique for controlling an alignment domain by devising an electrode shape without using a rubbing method or a photo-alignment method is also known. For example, there is a technique in which a rectangular opening is provided in each of two opposed electrodes, and the opening on one electrode side and the opening on the other electrode are alternately arranged without overlapping each other in plan view. Known (for example, Patent Document 5). In this prior art, an electric field that is not orthogonal to the upper and lower substrate surfaces (that is, an oblique electric field) is generated in the vicinity of the opening of each electrode, and thereby the liquid crystal molecules are tilted to align two openings with each opening as a boundary. An orientation domain is realized. In addition, a conventional technique that achieves the same effect by the action of a protrusion provided on a substrate is also known (for example, Patent Document 6).

  However, in the method based on the electrode shape, the size of each obtained orientation domain is very small, and it is difficult to enlarge the orientation domain. Another disadvantage is that it is difficult to realize a state other than a state in which the alignment directions of adjacent alignment domains differ by 180 °. Therefore, there is a demand for a novel alignment control technique that does not perform direct alignment processing on the substrate surface and can realize monodomain alignment of an arbitrary size at an arbitrary position.

JP 2005-234254 A Japanese Patent No. 2872628 JP 7-209647 A JP-A-11-95224 Japanese Patent No. 4107978 Japanese Patent No. 2947350

  A specific aspect of the present invention is to provide a liquid crystal display device capable of realizing monodomain alignment of an arbitrary size at an arbitrary position without performing direct alignment processing on the substrate surface.

  A liquid crystal display device according to one aspect (also referred to as “first aspect” for convenience) according to the present invention has a first substrate having a first electrode on one surface side, a second electrode on one surface side, and the second electrode. A second substrate disposed opposite to the first substrate such that the electrode and the first electrode of the first substrate face each other; a liquid crystal layer provided between the first substrate and the second substrate; , Including. The first electrode has a plurality of first openings each having a rectangular shape, and the second electrode has a plurality of second openings each having a rectangular shape. In the plurality of first openings, at least a part of each first side overlaps any one or more of the plurality of second openings in a plan view, and a second side facing the first side has In plan view, they are arranged so as to face the second electrode without overlapping any of the plurality of second openings.

  According to such a liquid crystal display device of the first aspect, an oblique electric field generated in the vicinity of the first side among the oblique electric fields generated in the vicinity of the first side and in the vicinity of the second side of each first opening. Can only function effectively. Thereby, an oblique electric field can be preferentially generated in only one direction in all the first openings and the second openings, and the liquid crystal molecules of the liquid crystal layer can be aligned along the oblique electric field. Accordingly, monodomain alignment can be realized in a region (effective display region) defined by the first opening and the second opening without performing direct alignment processing on the substrate surface. That is, by appropriately setting the arrangement of the first opening and the second opening, it is possible to realize monodomain alignment of an arbitrary size at an arbitrary position.

  In the above-described liquid crystal display device, each of the plurality of first openings and the plurality of second openings can be, for example, rectangular, and can be arranged with their longitudinal directions aligned in substantially the same direction.

  Thereby, the orientation direction of a monodomain orientation can be freely set by setting appropriately the direction which aligns each longitudinal direction of each 1st opening part and each 2nd opening part.

  In the liquid crystal display device, the plurality of first openings and the plurality of second openings may have substantially the same shape. Further, the first openings and the second openings may have different shapes. For example, the length in the long side direction of each of the plurality of second openings may be longer than that of each of the plurality of first openings.

  Thus, since the shape of each 1st opening part and each 2nd opening part has a freedom degree, it becomes possible to respond | correspond flexibly according to other design conditions.

  In the above-described liquid crystal display device, it is also preferable that each of the plurality of first openings is arranged to be relatively unevenly distributed on the best viewing azimuth side with respect to each of the plurality of second openings.

  Thereby, the orientation direction of monodomain orientation can be set according to the orientation desired to be the best viewing orientation.

  In the liquid crystal display device described above, it is also preferable that each of the plurality of first openings and the plurality of second openings is periodically arranged.

  Thereby, it is expected that the oblique electric field can be generated more uniformly.

  In the liquid crystal display device described above, one of the plurality of second openings may be disposed to be opposed to two or more of the plurality of first openings. Further, two or more of the plurality of second openings may be arranged to be opposed to each of the plurality of first openings.

  Thus, since there is a degree of freedom in the relative arrangement state of each first opening and each second opening, it is possible to flexibly cope with other design conditions and the like.

  In the above liquid crystal display device, the length of the short side orientation of each of the plurality of first openings and the plurality of second openings is preferably 5 μm to 40 μm, and preferably 7 μm to 30 μm. Is more preferable. In this case, the length of the long side orientation of each of the plurality of first openings and the plurality of second openings is longer than the length of the short side orientation and is 20 μm or more and 300 μm or less. Preferably, it is 20 μm or more and 200 μm or less.

  According to the above conditions, it is possible to realize monodomain alignment by generating a favorable oblique electric field without impairing the aperture ratio.

  In the above liquid crystal display device, the plurality of first openings are arranged such that a distance between edges of two adjacent first openings is 10 μm or more and 100 μm or less, and the plurality of second openings is mutually connected. It is preferable that the distance between the edges of two adjacent second openings is 10 μm or more and 100 μm or less.

  According to the above conditions, the alignment state of the liquid crystal molecules can be further stabilized.

  In the liquid crystal display device, for example, the other surface side of the first substrate is set as a display surface. In this case, each of the plurality of first openings and the plurality of second openings has a long side orientation of approximately 45 ° ± 10 from the substantially vertical orientation, the substantially horizontal orientation, or the vertical orientation on the display surface. It is preferable to arrange them according to any of the tilted directions (more preferably about 45 °).

  Thereby, the orientation azimuth | direction of monodomain orientation can be set according to various conditions, such as visual recognition direction at the time of observing a display, and arrangement | positioning of a polarizing plate.

  In the above liquid crystal display device, when a plurality of unit regions are provided in the effective display region where the first electrode and the second electrode overlap, the plurality of second regions are provided for each of the plurality of unit regions. It is also preferable that the long side orientation of each of the one opening and the plurality of second openings is different. Here, each of the plurality of unit regions is a region corresponding to, for example, a segment display unit or a dot matrix display unit. Each of the plurality of unit areas may be an area corresponding to one of the sub-pixels obtained by further dividing one pixel in the dot matrix display portion.

  Thereby, the orientation direction of monodomain orientation can be set individually for each unit region.

  A liquid crystal display device according to another aspect of the present invention (also referred to as a “second aspect” for convenience) includes a first substrate having a first electrode on one surface side, and a second electrode on the one surface side. A second substrate disposed opposite to the first substrate so that the two electrodes face the first electrode of the first substrate, and a liquid crystal layer provided between the first substrate and the second substrate And comprising. The first electrode has a plurality of first protrusions that are spaced apart from each other, and the second electrode has a plurality of second protrusions that are spaced from each other, Each of the plurality of first protrusions is arranged so that at least a part thereof overlaps one of the plurality of second protrusions in plan view.

  A liquid crystal display device according to another aspect of the present invention (also referred to as a “third aspect” for convenience) has a first substrate having a first electrode on one surface side, and a second electrode on one surface side. A second substrate disposed opposite to the first substrate so that the two electrodes face the first electrode of the first substrate, and a liquid crystal layer provided between the first substrate and the second substrate And comprising. The first electrode has a plurality of protrusions provided separately from each other, and the second electrode has a plurality of openings provided in a rectangular shape, and the plurality of protrusions. Each of the parts is arranged so that at least a part thereof overlaps any one of the plurality of openings in plan view.

  A liquid crystal display device according to another aspect of the present invention (also referred to as a “fourth aspect” for convenience) has a first substrate having a first electrode on one surface side, and a second electrode on one surface side. A second substrate disposed opposite to the first substrate so that the two electrodes face the first electrode of the first substrate, and a liquid crystal layer provided between the first substrate and the second substrate And comprising. The first electrode includes a plurality of first openings each provided in a rectangular shape, and a plurality of first protrusions provided separately from each other, and the second electrode includes A plurality of second openings provided in a rectangular shape and a plurality of second protrusions provided separately from each other. Each of the plurality of first protrusions is arranged so that at least a part thereof overlaps any one of the plurality of second openings in plan view, and each of the plurality of second protrusions is at least a part Is arranged so as to overlap with any one of the plurality of first openings in plan view.

  Each of the liquid crystal display devices of the second to fourth aspects as described above, that is, the liquid crystal display device of each aspect in which one or both openings are replaced with protrusions, Similar effects can be obtained.

FIG. 1 is a schematic cross-sectional view showing the structure of the liquid crystal display device of the first embodiment. FIG. 2 is a schematic diagram illustrating the structure of each first opening provided in the first electrode and each second opening provided in the second electrode in a plan view. FIG. 3 is a cross-sectional view schematically showing the structure of a liquid crystal display device of a comparative example. FIG. 4 is a plan view showing the arrangement of each first opening and each second opening in the liquid crystal display device of the comparative example. FIG. 5 is a diagram showing a photograph of an oriented structure during voltage application in the liquid crystal display device of the example. FIG. 6 is a diagram showing a photograph of an oriented structure during voltage application in the liquid crystal display device of the example. FIG. 7 is a diagram showing a photograph of an oriented structure at the time of voltage application in the liquid crystal display device of the comparative example described above. FIG. 8 is a diagram showing a photograph of an oriented structure at the time of voltage application in the liquid crystal display device of the comparative example described above. FIG. 9 is a diagram showing the measurement results of viewing angle characteristics of the liquid crystal display devices of the example and the comparative example when a voltage is applied. FIG. 10 is a diagram for explaining a modified example of the arrangement of the first openings and the second openings. FIG. 11 is a diagram illustrating a modification of the arrangement of the first openings and the second openings. FIG. 12 is a cross-sectional view schematically showing the structure of a liquid crystal display device according to a modification. FIG. 13 is a cross-sectional view schematically showing the structure of a liquid crystal display device according to a modification. FIG. 14 is a cross-sectional view schematically showing the structure of a liquid crystal display device according to a modification. FIG. 15 is a conceptual plan view schematically showing an example of a segment type liquid crystal display device. FIG. 16 is a conceptual plan view schematically showing another example of the segment type liquid crystal display device. FIG. 17 is a conceptual plan view schematically showing another example of the segment type liquid crystal display device. FIG. 18 is a conceptual plan view schematically showing an example of a liquid crystal display device having a plurality of display areas. FIG. 19 is a conceptual plan view schematically showing another example of a liquid crystal display device having a plurality of display areas. FIG. 20 is a conceptual plan view schematically showing another example of a liquid crystal display device having a plurality of display areas. FIG. 21 is a conceptual plan view schematically showing an example of the orientation control for each region in one pixel in the dot matrix type liquid crystal display device. FIG. 22 is a conceptual diagram schematically showing a liquid crystal display element of a comparative example. FIG. 23 is a conceptual plan view schematically showing another example of orientation control for each region in one pixel in a dot matrix type liquid crystal display device. FIG. 24 is a conceptual plan view schematically showing another example of the alignment control for each region in one pixel in the dot matrix type liquid crystal display device. FIG. 25 is a conceptual plan view schematically showing another example of the alignment control for each region in one pixel in the dot matrix type liquid crystal display device. FIG. 26 is a conceptual plan view schematically showing an example of the orientation control for each region in one segment in the segment type liquid crystal display device.

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

(First embodiment)
FIG. 1 is a schematic cross-sectional view showing the structure of the liquid crystal display device of the first embodiment. The liquid crystal display device 1 of the present embodiment shown in FIG. 1 includes a first substrate 11 and a second substrate 15 that are arranged to face each other, and a liquid crystal layer 14 that is arranged between the two substrates. A first polarizing plate 21 is disposed outside the first substrate 11, and a second polarizing plate 22 is disposed outside the second substrate 15. Hereinafter, the structure of the liquid crystal display device 1 will be described in more detail. Note that illustration and description of members such as a sealing material for sealing the periphery of the liquid crystal layer 14 are omitted.

  The first substrate 11 is a transparent substrate such as a glass substrate or a plastic substrate. Similar to the first substrate 11, the second substrate 15 is a transparent substrate such as a glass substrate or a plastic substrate. As illustrated, the first substrate 11 and the second substrate 15 are bonded to each other with a predetermined gap (for example, several μm) so that the first electrode 12 and the second electrode 16 face each other.

  The first electrode 12 is provided on one surface side of the first substrate 11. The first electrode 12 is configured by appropriately patterning a transparent conductive film such as indium tin oxide (ITO), for example. The first electrode 12 has a plurality of first openings (slits) 18 each having a rectangular shape. Each first opening 18 is formed by partially removing the first electrode 12. Details of each first opening 18 will be described later.

  The alignment film 13 is provided on one surface side of the first substrate 11 so as to cover the first electrode 12. In the present embodiment, as the alignment film 13, a film (vertical alignment film) that restricts the alignment state in the initial state (when no voltage is applied) of the liquid crystal layer 14 to the vertical alignment state is used.

  The second electrode 16 is provided on one surface side of the second substrate 15. Similar to the first electrode 12, the second electrode 16 is configured by appropriately patterning a transparent conductive film such as indium tin oxide (ITO), for example. The second electrode 16 has a plurality of second openings (slits) 19 each having a rectangular shape. Each second opening 19 is formed by partially removing the second electrode 16. Details of each second opening 19 will be described later.

  The alignment film 17 is provided on one surface side of the second substrate 15 so as to cover the second electrode 16. In the present embodiment, a vertical alignment film is used as the alignment film 17 in the same manner as the alignment film 13 described above.

  The liquid crystal layer 14 is provided between the first electrode 12 of the first substrate 11 and the second electrode 16 of the second substrate 15. In the present embodiment, the liquid crystal layer 14 is configured using a liquid crystal material having a negative dielectric anisotropy Δε (Δε <0). A thick line 20 illustrated in the liquid crystal layer 14 schematically shows the orientation direction of liquid crystal molecules when a voltage is applied to the liquid crystal layer 14 using the first electrode 12 and the second electrode 16. As described above, when no voltage is applied, the orientation direction of the liquid crystal molecules is substantially perpendicular to the substrate surfaces of the first substrate 11 and the second substrate 15. When the voltage is applied, the orientation direction of the liquid crystal molecules can be controlled to an angle corresponding to the magnitude of the voltage.

  FIG. 2 is a schematic diagram illustrating the structure of each first opening 18 provided in the first electrode 12 and each second opening 19 provided in the second electrode 16 in a plan view. In FIG. 2, each of the first opening 18 and the second opening 19 when viewed from the first substrate 11 side is shown in a plan view. In the figure, each first opening 18 is indicated by a solid line, and each second opening 19 is indicated by a dotted line. Hereinafter, the detailed structure of each opening and the action obtained by them will be described with reference to FIG. 2 and FIG. 1 described above.

  As shown in FIG. 2, each first opening 18 is formed in a rectangular shape extending in one direction (X direction shown in the figure), and is regularly arranged in the X direction and Y direction shown in the figure. Similarly, each 2nd opening part 19 is formed in the rectangular shape extended in one direction (X direction of illustration), and is regularly arranged in the X direction and Y direction of illustration. That is, the first openings 18 and the second openings 19 are arranged with their longitudinal directions aligned in substantially the same direction (the X direction in the drawing), and more specifically, the long sides of each are substantially parallel. It is arranged to become.

  FIG. 2 shows an example of the size of each first opening and each second opening. In the present embodiment, each first opening 18 has a long side length of 120 μm, a short side length of 20 μm, and a mutual distance (inter-edge distance) between adjacent first openings 18 in the short side orientation. Is 60 μm, and the distance (inter-edge distance) between the first openings 18 adjacent in the long side direction is 20 μm. These first openings 18 are periodically and continuously arranged in the effective display area with respect to each of the long side orientation (X direction) and the short side orientation (Y direction). Each second opening 19 is also set to have the same shape and size as each first opening 18, and each of the long side orientation (X direction) and the short side orientation (Y direction) is set within the effective display portion. It is continuously arranged periodically.

  As shown in FIG. 2, in the present embodiment, each first opening 18 is associated with any one of the second openings 19. The pair of first opening 18 and second opening 19 that are associated with each other are arranged to be opposed to each other in the short side direction so that only a part of each of them overlaps each other. More specifically, each first opening 18 has one long side (first side) overlapping with one second opening 19 in a plan view (that is, included), and the other length facing the first side. The side (second side) is disposed so as to face the second electrode 16 without overlapping any of the second openings 19 (see FIGS. 1 and 2). This is also true for each second opening 19. That is, when attention is paid to each second opening 19, each second opening 19 has one long side overlapping with one first opening 18 in plan view, and the other long side facing the first side. The first opening 18 is disposed so as not to overlap any of the first openings 18 so as to face the first electrode 12.

  According to the structure of the first opening 18 and the second opening 19 as described above, when a voltage is applied to the liquid crystal layer 14 using the first electrode 12 and the second electrode 16, each first opening 18 and each The oblique electric field generated in the vicinity of each edge of the second opening 19 can be preferentially functioned only in the vicinity of the first side which is one of the two long sides. Thereby, in all the first openings 18 and the second openings 19, an oblique electric field is generated only in one direction as shown by a dotted line in the liquid crystal layer 14 in FIG. Inclined orientation can only be achieved. Therefore, the monodomain alignment can be realized on almost the entire surface defined by each first opening 18 and each second opening 19.

Next, an example of the liquid crystal display device according to the first embodiment will be described.
In the liquid crystal display device of the example, a glass substrate having a predetermined plate thickness was used as each of the first substrate 11 and the second substrate 15. After forming an ITO film as a transparent conductive film on these glass substrates, a photoresist (PMER manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied on each ITO film with a roll coater and prebaked. Thereafter, the photoresist was irradiated with ultraviolet rays through a desired display pattern and a photomask corresponding to each of the first openings 18 and the second openings 19 described above. Next, the photoresist after ultraviolet irradiation was developed with a KOH aqueous solution, further post-baked, the ITO film was etched with a mixed aqueous solution of hydrochloric acid and sulfuric acid, and finally the photoresist was peeled off with a NaOH aqueous solution. As described above, the first electrode 12 made of an ITO film was formed on the one surface side of the first substrate 11, and the second electrode 16 made of the ITO film was formed on the one surface side of the second substrate 15. Each first opening 18 formed in the first electrode 12 has the shape and size shown in FIG. Similarly, each second opening 19 formed in the second electrode 16 has the shape and size shown in FIG.
Next, a liquid vertical alignment film material (manufactured by Chisso Petrochemical Co., Ltd.) is applied to each of the first substrate 11 and the second substrate 15 by flexographic printing, and baked at an appropriate temperature. Films 13 and 17 were formed.
Next, a plastic spacer having a particle size of approximately 2 μm is spread on one substrate (for example, the first substrate 11), and a sealing material (Mitsui Chemicals, Inc.) is disposed on the periphery of the other substrate (for example, the second substrate 15). Both substrates were bonded together after applying the sealing material). When the two substrates are bonded together, the first substrate 11 and the first substrate 11 are arranged so that only a part of each of the pair of the first opening 18 and the second opening 19 overlapped with each other as described above. The alignment with the second substrate 15 was performed. More specifically, in this embodiment, one long side (first side) of each first opening 18 is about 2 μm from the one long side (edge) of the corresponding second opening 19, 2 It was set as the state which penetrated into the opening part 19 (it included).
Next, a liquid crystal material (made by Merck) having a refractive index anisotropy Δn> 0.2 and a dielectric anisotropy Δε <0 is injected into the gap between the first substrate 11 and the second substrate 15 by a vacuum injection method. Then, after sealing the injection port, it was baked at 120 ° C. for 1 hour.
Finally, the first polarizing plate 21 was attached to the outside of the first substrate 11, and the second polarizing plate 22 was attached to the outside of the second substrate 15. Each of the first polarizing plate 21 and the second polarizing plate 22 has an absorption axis of approximately 45 ° with respect to the respective long side orientations of the first opening 18 and the second opening 19, and a crossed Nicol state. Arranged to be. Finally, a lead frame (both not shown) was attached to the external extraction electrode portion to complete the liquid crystal display device 1.

  In addition, a liquid crystal display device as a comparative example with respect to the above-described embodiment was also manufactured. FIG. 3 is a cross-sectional view schematically showing the structure of a liquid crystal display device of a comparative example. FIG. 4 is a plan view showing the arrangement of each first opening and each second opening in the liquid crystal display device of the comparative example. The difference between the example and the comparative example is that the positional relationship between each first opening 18 and each second opening 19 is as shown in FIGS. 3 and 4, and the first opening 18 and the second opening 19. Are arranged so as not to overlap each other in plan view. More specifically, in the liquid crystal display device of the comparative example, one first opening 18 overlaps between two adjacent second openings 19. Since other structures are manufactured in common in the first embodiment and the comparative example, the same reference numerals are given to the respective constituent elements, and detailed descriptions thereof are omitted.

  FIG. 5 and FIG. 6 are diagrams showing alignment texture photographs at the time of voltage application in the liquid crystal display device of the above-described embodiment. The first polarizing plate 21 on the upper side is arranged with the absorption axis set in the direction of about 45 ° counterclockwise with respect to the long side direction of each first opening 18, and the second polarizing plate on the lower side. The plate 22 was arranged with the absorption axis set so as to be crossed Nicol with respect to the absorption axis of the upper first polarizing plate 21. According to FIG. 5, dark regions are observed between the two first openings 18 adjacent to each other in the long side direction and between the two second openings 19, and the spacers distributed in the plane and their surroundings are observed. A dark region is observed in the part, but non-uniformity of the alignment is not observed in other cases. From this, it is presumed that a regular alignment state is realized.

  FIG. 6 is basically observed under the same conditions as the orientation texture photograph shown in FIG. 5, but the method of the substrate surface with respect to the short side orientation of each first opening 18 or each second opening 19. It is different in that it is observed at an angle of about 10 ° from the line direction. As shown in FIG. 6, the regions corresponding to the respective first openings 18 and the second openings 19, and the mutual long sides of the first openings 18 and the second openings 19. It can be seen that equal transmittance is obtained in regions other than the region. From this, it is considered that in the liquid crystal display device of the example, the monodomain alignment in which the alignment direction of the liquid crystal molecules is equal is realized in the majority (the portion where the transmittance is equal).

  7 and 8 are diagrams showing alignment texture photographs at the time of voltage application in the liquid crystal display device of the comparative example described above. The setting of the absorption axis of each of the first polarizing plate 21 and the second polarizing plate 22 is the same as that in the above-described embodiment. According to FIG. 7, a cross-shaped dark region is observed between the two first openings 18 adjacent to each other in the long side direction and between the two second openings 19, and the spacers are further dispersed in the plane. In addition, dark regions are observed at the periphery thereof, but non-uniformity of alignment is not observed otherwise. From this, it is presumed that a regular alignment state is realized.

  FIG. 8 is basically observed under the same conditions as the orientation texture photograph shown in FIG. 7, but the method of the substrate surface with respect to the short side orientation of each first opening 18 or each second opening 19 is shown. It is different in that it is observed at an angle of about 10 ° from the line direction. As shown in FIG. 8, the transmittance of each region with respect to each short side orientation of each first opening 18 and each second opening 19 with each first opening 18 and each second opening 19 as a boundary. Different states are observed. This is presumably because the orientation directions of the liquid crystal molecules differ by 180 °. That is, it is considered that the two-domain orientation is realized.

  FIG. 9 is a diagram showing the measurement results of viewing angle characteristics of the liquid crystal display devices of the example and the comparative example when a voltage is applied. The measurement of the viewing angle characteristic was performed on an LCD 5200 manufactured by Otsuka Electronics. Specifically, the transmittance change is measured when a driving voltage equal to or higher than the threshold voltage is applied and the observation angle is changed with respect to the respective short side orientations of the first openings 18 and the second openings 19. It was done. 2 and 4, the upper direction corresponds to a positive observation angle, and the lower direction corresponds to a negative observation angle. The vertical axis indicates the relative transmittance with the front observation taken as 1. In FIG. 9, the circle plot indicates the viewing angle of the liquid crystal display device of the example. As shown by this viewing angle specification, in the liquid crystal display device of the example, an up-down asymmetric transmittance characteristic with the upper direction as the best viewing direction is obtained. At the time of application, it is considered that monodomain orientation is realized in almost all regions except the regions of the first openings 18 and the second openings 19. On the other hand, in FIG. 9, the viewing angle characteristic of the liquid crystal display device of the comparative example shown by the triangular plot is a transmittance change symmetrical in the vertical direction. This indicates that a two-domain orientation is obtained.

  In addition to the above-described embodiments, the inventor of the present application examined various conditions regarding the size, arrangement state, etc. of each first opening 18 and each second opening 19. The results are described below.

  First, the result of examining how much the first opening 18 and the second opening 19 facing each other can be overlapped will be described. In this regard, it has been found that monodomain alignment can be obtained unless the first opening 18 and the second opening 19 facing each other completely overlap. That is, as long as only one long side (first side) of the first opening 18 is included in the second opening 19, most of the areas other than the regions of the first opening 18 and the second opening 19 are used. It was found that monodomain orientation can be realized in the region.

  Next, the examination result about each size and arrangement | positioning space | interval of each 1st opening part 18 and each 2nd opening part 19 is demonstrated. The short side length of each first opening 18 and each second opening 19 is an important factor with respect to the aperture ratio of the liquid crystal display device. Therefore, in consideration of this, it is preferably 5 μm or more and 40 μm or less, and preferably 7 μm or more and 30 μm or less. Is more preferable. The long side length of each first opening 18 and each second opening 19 is preferably 20 μm or more and 300 μm or less, and more preferably 20 μm or more and 200 μm or less in order to correspond to an arbitrary display pattern. Moreover, it is preferable that the mutual distance in the long side direction of the two adjacent 1st opening parts 18 shall be below the above short side length. The same applies to the mutual distance in the long side direction of the two adjacent second openings 19. In addition, the distance between the two adjacent first openings 18 in the short side orientation is a factor that greatly contributes to the stability of the alignment state. Therefore, in consideration of this, the distance is preferably 10 μm or more and 100 μm or less, and 20 μm or more and 60 μm or less. More preferably. The same applies to the distance between the adjacent two second openings 19 in the short side direction.

Next, another aspect of the arrangement of the first openings 18 and the second openings 19 will be described.
For example, as shown in FIG. 10, each first opening 18 and each second opening 19 are arranged so that each first opening 18 faces two adjacent second openings 19. Also good. That is, in this example, a part of one long side (first side) of each first opening 18 is configured to overlap with each of the opposing second openings 19.

  Moreover, each 1st opening part 18 and each 2nd opening part 19 do not need to be made into the same shape. For example, as shown in FIG. 11, the long side length of each second opening 19 may be set longer than each first opening 18. In the example shown in FIG. 11, one second opening 19 is configured to face three first openings 18.

  Moreover, although illustration is abbreviate | omitted, the short side length of each 1st opening part 18 and each 2nd opening part 19 does not need to correspond between both. Furthermore, each 1st opening part 18 or each 2nd opening part 19 does not necessarily need to be rectangular shape, and may be square shape. In any of these aspects, the monodomain orientation as described above is realized as long as the long sides of each first opening 18 are not included in the second opening 19 facing both sides.

  Next, another embodiment will be described. In the above-described embodiments and examples, the monodomain is obtained by disposing the first opening provided on the first electrode side and the second opening provided on the second electrode side relative to each other under a predetermined condition. Although the orientation has been realized, the same effect can be obtained by replacing at least one of the first opening and the second opening with a protrusion (projection).

  12 to 14 are cross-sectional views schematically showing the structure of a liquid crystal display device according to a modification. In addition, the same code | symbol is used about the element which is common in the liquid crystal display device 1 concerning above-described embodiment, and description is abbreviate | omitted about them.

  The liquid crystal display device 1a shown in FIG. 12 is also spaced apart from the first electrode 32 having a plurality of first protrusions 38 spaced apart at a predetermined interval (for example, a constant interval) at the same predetermined interval (for example, a constant interval). And a second electrode 36 having a plurality of second projecting portions 39 arranged in this manner. For example, each first protrusion 38 is provided with protrusions made of an insulator or the like on one surface of the first substrate 11 in advance, and the first electrode 32 is formed so as to cover the protrusions. can get. Similarly, for each of the second protrusions 39, for example, protrusions made of an insulator or the like are provided in advance on one surface of the second substrate 12, and the second electrode 36 is formed so as to cover the protrusions. It is obtained by doing. The height of each first protrusion 38 and each second protrusion 39 is preferably about 0.1 μm to 5 μm, and the width of the bottom is preferably about 20 μm to 80 μm (the same applies to the modifications shown below). In addition, the distance between the first protrusions 38 and the distance between the second protrusions 39 are each preferably about 20 μm to 80 μm (the same applies to the modifications shown below).

  In the present modification, each of the first protrusions 38 is disposed so as to partially overlap with one of the second protrusions 39 in plan view. In other words, each first protrusion 38 is arranged so that at least a portion thereof overlaps the opposing second protrusion 39 in the vertical direction in the figure. Also in the liquid crystal display device 1a having such a configuration, monodomain alignment at the time of voltage application can be realized. In the example shown in FIG. 12, the shape of each first protrusion 38 and each second protrusion 39 is triangular, but the shape is not limited to this, and other shapes (for example, a trapezoidal cross section) Etc.) (the same applies to the modifications shown below).

  The liquid crystal display device 1b of the example shown in FIG. 13 has an intermediate structure between the liquid crystal display device 1 and the liquid crystal display device 1a. Specifically, the liquid crystal display device 1b includes a first electrode 42 having a plurality of protrusions 48 arranged at a predetermined interval (for example, a constant interval), and a plurality of openings similarly arranged at a predetermined interval (for example, a constant interval). And a second electrode 46 having a portion 49. The structure of each protrusion 48 is the same as that of the first protrusion 38 described above. The structure of each opening 49 is the same as that of the second opening 19 described above. In the present modification, each of the protrusions 48 is disposed so as to partially overlap with any one of the openings 49 in plan view. In other words, each protrusion 48 is arranged so that at least a portion thereof overlaps the opening 49 facing each other in the vertical direction in the drawing. Also in the liquid crystal display device 1b having such a configuration, monodomain alignment at the time of voltage application can be realized.

  The liquid crystal display device 1c of the example shown in FIG. 14 is a further modified embodiment of the above-described liquid crystal display device 1b. Specifically, the liquid crystal display device 1c includes a first electrode 52 having a plurality of first protrusions 58 arranged at a predetermined interval (for example, a constant interval) and a plurality of first openings 59 arranged at a predetermined interval. And a second electrode 56 having a plurality of second protrusions 68 arranged at a predetermined interval (for example, a constant interval) and a plurality of second openings 69 arranged at a predetermined interval. Yes. The structure of the first protrusion 58 is the same as that of the first protrusion 38 described above, and the structure of the first opening 59 is the same as that of the first opening 18 described above. The structure of the second protrusion 59 is the same as that of the second protrusion 39 described above, and the structure of the second opening 59 is the same as that of the second opening 19 described above. In the present modification, each of the first protrusions 58 is disposed so as to partially overlap with one of the second openings 69 in plan view. In other words, each first protrusion 58 is arranged so that at least a part thereof overlaps the opposing second opening 69 in the vertical direction in the figure. Similarly, each of the second protrusions 68 is disposed so as to partially overlap one of the first openings 59 in plan view. In other words, each of the second protrusions 68 is arranged so that at least a part thereof overlaps the opposing first opening 59 in the vertical direction in the figure. Also in the liquid crystal display device 1c having such a configuration, monodomain alignment at the time of voltage application can be realized.

(Second Embodiment)
In the first embodiment described above, a liquid crystal display device has been described in which monodomain alignment is realized over the entire effective display area when a voltage is applied, and the best viewing orientation can be set at a certain position. However, depending on the use of the liquid crystal display device, it may be desired that the display can be observed well from a plurality of directions. Therefore, hereinafter, a liquid crystal display device that realizes multi-domain alignment as a whole by applying the technique according to the first embodiment to monodomain alignment for each arbitrary unit region will be described.

(Orientation control for each segment)
For example, each segment display unit can be a unit region, and the orientation direction of liquid crystal molecules in each segment can be freely set. Details will be described below.

  FIG. 15 is a conceptual plan view schematically showing an example of a segment type liquid crystal display device. In the liquid crystal display device 100a, the upper segment display section “LEFT” is best observed from the left side when viewed from the front as shown, and the lower segment display section “RIGHT” is viewed from the front as illustrated. It is configured so that the best viewing state from the right direction is realized. Specifically, as shown in an enlarged view in FIG. 15, each first opening 11 and each second opening 19 has a long side orientation (longitudinal direction) from the front of the liquid crystal display device 100a. They are arranged so as to coincide with the vertical direction when viewed. The absorption axes of the first polarizing plate 21 that is the upper polarizing plate and the second polarizing plate 22 that is the lower polarizing plate are the long sides of the first opening 18 and the second opening 19 as shown in the figure. It is arranged at approximately 45 ° counterclockwise / clockwise with respect to the bearing. That is, the long sides of each first opening 18 and each second opening 19 and the respective absorption axes of the first polarizing plate 21 and the second polarizing plate 22 are arranged so as to have an angle of about 45 °. Has been.

  In the above-described liquid crystal display device 100a, in the upper segment display portion “LEFT”, the first openings 18 are arranged to be shifted to the left relative to the second openings 19. That is, the first openings 18 are unevenly distributed on the left side, which is the side where the best viewing orientation is desired, with respect to the second openings 19. As a result, the orientation direction of the liquid crystal molecules in the upper segment display portion “LEFT” at the time of voltage application is the right orientation in most parts except the vicinity of each opening, and the best viewing orientation in this segment display portion is the left orientation. Similarly, in the lower segment display part “RIGHT”, the first openings 18 are arranged so as to be shifted to the right relative to the second openings 19. That is, the first openings 18 are unevenly distributed to the right side, which is the side where the best viewing orientation is desired, with respect to the second openings 19. As a result, the orientation direction of the liquid crystal molecules in the lower segment display portion “RIGHT” at the time of voltage application is the left orientation in the majority except for the vicinity of each opening, and the best viewing orientation in this segment display portion is the right orientation.

  FIG. 16 is a conceptual plan view schematically showing another example of the segment type liquid crystal display device. In the liquid crystal display device 100b, as shown in FIG. 16, the absorption axis of the first polarizing plate 21, which is the upper polarizing plate, coincides with the left-right direction when the liquid crystal display device 100b is viewed from the front. The absorption axis of the second polarizing plate 22 that is a plate is set to coincide with the vertical direction. For example, if you want to suppress light leakage in the left and right directions when no voltage is applied, or if the observer is wearing polarized sunglasses, the display brightness experienced by the observer should not be too dark. Applies to cases.

  Also in the liquid crystal display device 100b described above, in the upper segment display section “LEFT”, the first opening 18 is located on the upper left side (45 ° azimuth), which is the side where the first opening 18 is desired to be the best viewing direction. It is unevenly distributed. As a result, the orientation direction of the liquid crystal molecules in the upper segment display portion “LEFT” at the time of voltage application is in the lower right most of the area except for the vicinity of each opening, and the best viewing orientation in this segment display portion is the upper left orientation (upper left 45 ° azimuth). In the lower segment display section “RIGHT”, the first openings 18 are unevenly distributed to the lower right side, which is the side where the best viewing orientation is desired, with respect to the second openings 19. As a result, the orientation direction of the liquid crystal molecules in the lower segment display portion “RIGHT” at the time of voltage application is the upper left orientation in most portions except near each opening, and the best viewing orientation in this segment display portion is the lower right position (right Lower 45 ° azimuth).

  FIG. 17 is a conceptual plan view schematically showing another example of the segment type liquid crystal display device. In the liquid crystal display device 100c, as shown in FIG. 17, the absorption axis of the first polarizing plate 21, which is the upper polarizing plate, coincides with the horizontal direction when the liquid crystal display device 100c is viewed from the front, and the lower polarization The absorption axis of the second polarizing plate 22 that is a plate is set to coincide with the vertical direction. That is, the arrangement of the absorption axis of each polarizing plate is the same as that of the liquid crystal display device 100b described above. Such a setting is obtained when observing the liquid crystal display device 100c from an upper direction (for example, about 20 °), when observing from the upper left side (for example, 45 ° upper side) and from the upper right side (for example, 45 ° upper side). It is suitable for the case where it is desired to prevent a large difference in display luminance perceived by the observer between the upper segment display section “LEFT” and the lower segment display section “RIGHT” at any time of observation.

  In the above-described liquid crystal display device 100c, the upper segment display section “LEFT” has an upper left side (upper left 45 ° azimuth) that is the side where each first opening 18 is desired to be the best viewing direction with respect to each second opening 19. Is unevenly distributed. As a result, the orientation direction of the liquid crystal molecules in the upper segment display portion “LEFT” at the time of voltage application is in the lower right most of the area except for the vicinity of each opening, and the best viewing orientation in this segment display portion is the upper left orientation (upper left 45 ° azimuth). Further, in the lower segment display portion “RIGHT”, the first openings 18 are unevenly distributed on the upper right side (upper right 45 ° azimuth), which is the side where the best viewing orientation is desired, with respect to the second openings 19. . As a result, the orientation direction of the liquid crystal molecules in the lower segment display portion “RIGHT” at the time of voltage application is in the lower left most of the area except for the vicinity of each opening, and the best viewing orientation in this segment display portion is the upper right orientation (upper right 45 ° azimuth).

  As described above, by setting each segment display unit as a unit region and setting the arrangement of each first opening and each second opening in each segment display unit, the orientation direction of the liquid crystal molecules in each segment display unit is set. It can be set freely. From the viewpoint of placing more emphasis on light utilization efficiency, each first opening 18 and each second opening 19 has an absorption axis of each of the first polarizing plate 21 and the second polarizing plate 22 in the long side direction. Is preferably set within a range of about 45 ° ± 10 °.

(Orientation control for each display area)
Each display area can be a unit region, and the orientation direction of liquid crystal molecules in each display area can be set freely. The details will be described below.

  FIG. 18 is a conceptual plan view schematically showing an example of a liquid crystal display device having a plurality of display areas. The liquid crystal display device 100d has a segment display unit on each of the left and right sides when viewed from the front and a dot matrix display unit in the center, and is used as a display unit of an air conditioner, for example. In the liquid crystal display device 100d, the left segment display unit is best (more preferentially) observed from the left side when viewed from the front, and the right segment display unit is best (right from the right side) when viewed from the front. The center dot matrix display unit is configured so that it can be observed well from either the left or right direction. Specifically, as shown in the enlarged view in FIG. 18, in each of the left and right segment display portions, each first opening 18 and each second opening 19 has its long side orientation (longitudinal direction). Are arranged in the vertical direction when the liquid crystal display device 100d is viewed from the front. In the central dot matrix display section, the first openings 18 and the second openings 19 are arranged such that the long side orientations (longitudinal directions) coincide with the left and right directions when the liquid crystal display device 100d is viewed from the front. Has been. The absorption axes of the first polarizing plate 21 that is the upper polarizing plate and the second polarizing plate 22 that is the lower polarizing plate are the long sides of the first opening 18 and the second opening 19 as shown in the figure. It is arranged at approximately 45 ° counterclockwise / clockwise with respect to the bearing. That is, the long sides of each first opening 18 and each second opening 19 and the respective absorption axes of the first polarizing plate 21 and the second polarizing plate 22 are arranged so as to have an angle of about 45 °. Has been.

  In the liquid crystal display device 100d described above, in the left segment display section, the upper first openings 18 are arranged so as to be shifted to the left relative to the lower second openings 19. That is, the first openings 18 are unevenly distributed on the left side, which is the side where the best viewing orientation is desired, with respect to the second openings 19. As a result, the orientation direction of the liquid crystal molecules in the left segment display portion at the time of voltage application is the right orientation in most parts except the vicinity of each opening, and the best viewing orientation in this segment display portion is the left orientation. Similarly, in the segment display portion on the right side, the first openings 18 are arranged so as to be shifted to the right relative to the second openings 19. That is, the first openings 18 are unevenly distributed to the right side, which is the side where the best viewing orientation is desired, with respect to the second openings 19. As a result, the orientation direction of the liquid crystal molecules in the right segment display portion at the time of voltage application is the left orientation in the majority except for the vicinity of each opening, and the best viewing orientation in this segment display portion is the right orientation. Further, in the central dot matrix display portion, the first openings 18 are arranged so as to be shifted upward relative to the second openings 19. That is, the first openings 18 are unevenly distributed on the upper side, which is the side where the best viewing orientation is desired, with respect to the second openings 19. As a result, the orientation direction of the liquid crystal molecules in the dot matrix display portion at the time of voltage application is in the lower position in most parts except for the vicinity of each opening, and the best viewing direction in this segment display portion is the upper direction.

  FIG. 19 is a conceptual plan view schematically showing another example of a liquid crystal display device having a plurality of display areas. The liquid crystal display device 100e basically has the same configuration as the above-described liquid crystal display device 100d, and the configuration of the central dot matrix display section is different. Specifically, as shown in the enlarged view in FIG. 19, in the central dot matrix display portion, each first opening 18 and each second opening 19 has its long side orientation (longitudinal direction). Are arranged so as to coincide with the vertical direction when the liquid crystal display device 100e is viewed from the front. In the liquid crystal display device 100e, in the central dot matrix display portion, the first openings 18 and the second openings 19 are alternately arranged along the horizontal direction in the figure without overlapping each other. Thereby, the dot matrix display unit at the time of voltage application has two domains in which the orientation direction of the liquid crystal molecules is 180 ° different from the short side direction with each first opening 18 and each second opening 19 as a boundary. Orientation. In the left and right segment display portions, as described above, the orientation direction of the liquid crystal molecules is a monodomain orientation. That is, according to the liquid crystal display device 100e of this example, it is possible to mix monodomain alignment and two-domain alignment.

  FIG. 20 is a conceptual plan view schematically showing another example of a liquid crystal display device having a plurality of display areas. As in the liquid crystal display device 100c described above, the liquid crystal display device 100f has an absorption axis of the first polarizing plate 21 that is the upper polarizing plate as viewed from the front, as shown in FIG. The absorption axis of the second polarizing plate 22 that is the lower polarizing plate coincides with the vertical direction. In the liquid crystal display device 100f, in the left segment display section, each first opening 18 is unevenly distributed to the left upper side (45 ° azimuth), which is the side where the best viewing orientation is desired, with respect to each second opening 19. . As a result, the orientation direction of the liquid crystal molecules in the left segment display portion when a voltage is applied is in the lower right most of the area except for the vicinity of each opening, and the best viewing orientation in this segment display portion is the upper left orientation (upper left 45 ° orientation). It becomes. Moreover, in the segment display part on the right side, each first opening 18 is unevenly distributed on the upper right side, which is the side where the best viewing orientation is desired, with respect to each second opening 19. As a result, the orientation direction of the liquid crystal molecules in the right segment display portion when a voltage is applied is in the lower left position in most parts except near each opening, and the best viewing orientation in this segment display portion is the upper right orientation (upper right 45 ° orientation). Become. Further, in the central dot matrix display portion, the first openings 18 and the second openings 19 are alternately arranged in a non-overlapping manner, and the respective long side orientations are arranged along the 45 ° azimuth direction to the right. Has been. Thereby, the dot matrix display unit at the time of voltage application has two domains in which the orientation direction of the liquid crystal molecules is 180 ° different from the short side direction with each first opening 18 and each second opening 19 as a boundary. Orientation. That is, the liquid crystal display device 100f of this example can also mix the monodomain alignment and the two-domain alignment.

  As described above, each display area is a unit region, and the arrangement of each first opening 18 and each second opening 19 is set for each display area, so that the orientation direction of liquid crystal molecules in each display area can be freely set. Can be set to From the viewpoint of placing more emphasis on light utilization efficiency, each first opening 18 and each second opening 19 has an absorption axis of each of the first polarizing plate 21 and the second polarizing plate 22 in the long side direction. Is preferably set within a range of about 45 ° ± 10 °. Further, in the liquid crystal display devices of the examples shown in FIGS. 18 to 20, the orientation direction of the liquid crystal molecules is set for each display area and is set to three directions as a whole. It is possible to set more than one direction. In the above-described embodiment, the segment display unit is controlled to have a monodomain orientation. However, by a similar method, a unit region is set for each of a plurality of pixel units in a dot matrix type display unit, and the unit is set. It is also possible to realize monodomain orientation for each region.

(Orientation control within one pixel)
Each pixel in the dot matrix type liquid crystal display device can be divided into a plurality of regions, and the orientation direction of the liquid crystal molecules can be freely set in each region. Details will be described below.

  FIG. 21 is a conceptual plan view schematically showing an example of the orientation control for each region in one pixel in the dot matrix type liquid crystal display device. The liquid crystal display device assumed in the present embodiment is a so-called segment electrode in which the upper first electrode 12 is formed in a strip shape along the vertical direction in the figure, and the lower second electrode 16 in the horizontal direction in the figure. Assume that the electrode is a so-called common electrode formed in a strip shape. Other configurations are the same as those of the liquid crystal display device shown in FIG. In this liquid crystal display device, a rectangular region where the first electrode 12 and the second electrode 16 overlap corresponds to one pixel, and FIG. 21 schematically shows the configuration for one pixel. The size of one pixel is, for example, 400 μm square. Each first opening 18 and each second opening 19 are arranged such that the long side orientation (longitudinal direction) coincides with the vertical direction when viewed from the front. The absorption axes of the first polarizing plate 21 that is the upper polarizing plate and the second polarizing plate 22 that is the lower polarizing plate are the long sides of the first opening 18 and the second opening 19 as shown in the figure. It is arranged at approximately 45 ° counterclockwise / clockwise with respect to the bearing. That is, each of the first openings 18 and the second openings 19 is arranged so that the long side orientation and the absorption axes of the first polarizing plate and the second polarizing plate have an angle of about 45 °. Yes.

  In the region corresponding to one pixel shown in FIG. 21, only the first opening 18 is provided at the center in the vertical direction in the drawing, and this portion is a boundary where the alignment direction of the liquid crystal molecules is different by 180 ° in the vertical direction. On the upper side of this boundary, the first opening 18 is unevenly distributed and overlaps relative to the second opening 19, and on the lower side of this boundary, the first opening 18 is the second opening 19. Are relatively unevenly distributed downward. As a result, when a voltage is applied, the liquid crystal molecules are oriented in directions corresponding to the arrangement state of the first opening 18 and the second opening 19 in the upper half and the lower half of the above-described boundary (indicated schematically by arrows in the figure). Monodomain orientation). That is, a two-domain orientation within one pixel is realized. Here, FIG. 22 shows a case where the above-described comparative example (FIGS. 3 and 4) is applied to a region for one pixel. In this comparative example, the orientation directions of the liquid crystal molecules (schematically indicated by arrows in the figure) with each first opening 19 on the first electrode 12 side and each second opening 19 on the second electrode 16 side as a boundary. ) Are 180 ° different multi-domain orientations. Compared to this comparative example, in the embodiment shown in FIG. 21, the region that becomes the monodomain orientation when a voltage is applied has a wider area.

  FIG. 23 is a conceptual plan view schematically showing another example of orientation control for each region in one pixel in a dot matrix type liquid crystal display device. The basic configuration of the liquid crystal display device assumed in this embodiment is the same as that of the liquid crystal display device shown in FIG. In the liquid crystal display device of this example, the region for one pixel is divided into four, and monodomain alignment is realized for each region, and the 4-domain alignment is realized as a whole. Specifically, in the upper left area and lower right area in one pixel, each first opening 18 is unevenly distributed upward relative to each second opening, and the upper right area in one pixel is In the region and the lower left region, the first openings 18 are unevenly distributed downward relative to the second openings. Thereby, as schematically shown by arrows in the figure, checkered alignment patterns having different alignment directions of liquid crystal molecules in four regions in one pixel are obtained. In this example, the configuration example in which the orientation direction of the liquid crystal molecules is set in the vertical direction in one pixel is shown. However, the long side orientations of the first openings 18 and the second openings 19 are different by 90 °. Thus, the orientation direction of the liquid crystal molecules can be set in the left-right direction.

  FIG. 24 is a conceptual plan view schematically showing another example of the alignment control for each region in one pixel in the dot matrix type liquid crystal display device. The basic configuration of the liquid crystal display device assumed in this embodiment is the same as that of the liquid crystal display device shown in FIG. The liquid crystal display device shown in FIG. 24 has a configuration in which the long side orientations of the first openings 18 and the second openings 19 in the liquid crystal display device shown in FIG. In addition, the absorption axes of the first polarizing plate 21 and the second polarizing plate 22 are also set to orientations rotated 45 ° clockwise. In this liquid crystal display device, the orientation direction of liquid crystal molecules is set to be 180 ° different between the upper right region and the lower left region across the diagonal line in one pixel. Although not shown in the figure, by arranging the first openings 18 and the second openings 19 symmetrically with the example shown in FIG. 24, the upper left area and the right side across the diagonal line in one pixel It can also be set so that the orientation direction of the liquid crystal molecules differs by 180 ° in the lower region.

  FIG. 25 is a conceptual plan view schematically showing another example of the alignment control for each region in one pixel in the dot matrix type liquid crystal display device. The basic configuration of the liquid crystal display device assumed in this embodiment is the same as that of the liquid crystal display device shown in FIG. In the liquid crystal display device of this example, the area for one pixel is divided into two parts, upper and lower, and monodomain alignment is realized for each area, and two-domain alignment is realized as a whole. Specifically, in the upper region in one pixel, each first opening 18 is unevenly distributed to the upper right side relative to each second opening 19, and each first opening 18 in each lower region in one pixel. The openings 18 are unevenly distributed to the lower right side relative to the second openings 19. Thus, when a voltage is applied, the liquid crystal molecules are oriented in directions corresponding to the arrangement state of the first opening 18 and the second opening 19 (indicated by arrows in the figure) in each of the upper half and the lower half of the boundary. Monodomain orientation). That is, in one pixel, two-domain alignment is realized in which the alignment directions of the upper and lower liquid crystal molecules are different by 90 ° or 270 °. In this example, neither the first opening 18 nor each second opening 19 is provided in the center of the vertical direction of the pixel that becomes a boundary for changing the orientation direction of the liquid crystal molecules by 180 °. Of course, it is obvious that one pixel can be divided into four orientation directions.

  As described above, each pixel can be a unit region, and each pixel can be divided into a plurality of regions (sub-pixels), and the orientation direction of liquid crystal molecules in each region can be arbitrarily set. In each example described above, one pixel is divided into four regions at the maximum, but this is not restrictive, and the number of divisions can be further increased. In each example, from the viewpoint of placing more importance on light utilization efficiency, each first opening 18 and each second opening 19 has a longer side orientation of each of the first polarizing plate and the second polarizing plate. It is preferable to set within a range of about 45 ° ± 10 ° with respect to each absorption axis.

(Orientation control within one segment)
Each segment in the segment type liquid crystal display device can be divided into a plurality of regions, and the orientation direction of the liquid crystal molecules can be freely set in each region. Details will be described below.

  FIG. 26 is a conceptual plan view schematically showing an example of the orientation control for each region in one segment in the segment type liquid crystal display device. For example, in a liquid crystal display device having a 7-segment display pattern illustrated in FIG. 26A, it is considered that multi-domain alignment of two alignment directions is realized in each segment. The specific configuration of the liquid crystal display device is the same as that of the above-described embodiment. In this case, in consideration of arbitrary display patterns, regular square (eg, 200 μm square) orientation domains as shown in FIG. 26B are arranged in a checkered pattern, and FIG. When the display patterns of the segment display section shown in FIG. 5 are overlapped, the first opening 18 and the second opening are formed in the first electrode 12 and the second electrode 16 (see FIG. 1 and the like) of the overlapping portion. By arranging 19, as shown in FIG. 26C, monodomain alignment can be realized in each of a plurality of regions in each segment, and multidomain alignment can be realized as a whole.

  In addition, this invention is not limited to the content of embodiment mentioned above, In the range of the summary of this invention, it can change and implement variously. For example, in the above description, each first opening and each second opening is illustrated as a rectangular shape, but each first opening and each second opening may be square. . In the second embodiment, an embodiment in which the first opening provided on the first electrode side and the second opening provided on the second electrode side are disposed relative to each other under a predetermined condition is used. However, it is also possible to use an embodiment in which at least one of the first opening and the second opening is replaced with a protrusion (projection). In the above description, the liquid crystal molecules in the liquid crystal layer 14 when no voltage is applied are vertically aligned (pretilt angle is approximately 90 °) and the dielectric anisotropy is negative. The present invention can also be applied to the case where the molecules are horizontally oriented (the pretilt angle is approximately 0 °) and the dielectric anisotropy is positive.

  DESCRIPTION OF SYMBOLS 1 ... Liquid crystal display device, 11 ... 1st board | substrate, 12 ... 1st electrode, 13 ... Orientation film, 14 ... Liquid crystal layer, 15 ... 2nd board | substrate, 16 ... 2nd electrode, 17 ... Orientation film, 18 ... 1st opening Part, 19 ... second opening, 21 ... first polarizing plate, 22 ... second polarizing plate

Claims (17)

A first substrate having a first electrode on one side;
A second substrate having a second electrode on one side, the second substrate being disposed opposite to the first substrate so that the second electrode and the first electrode of the first substrate face each other;
A liquid crystal layer provided between the first substrate and the second substrate;
Including
The first electrode has a plurality of first openings each provided in a rectangular shape,
The second electrode has a plurality of second openings each provided in a rectangular shape,
In the plurality of first openings, at least a part of each first side overlaps any one or more of the plurality of second openings in a plan view, and a second side facing the first side has A liquid crystal display device arranged to face the second electrode without overlapping any of the plurality of second openings in a plan view.   2. The liquid crystal display device according to claim 1, wherein the plurality of first openings and the plurality of second openings have a rectangular shape, and are arranged with their longitudinal directions aligned in substantially the same direction.   The liquid crystal display device according to claim 2, wherein the plurality of first openings and the plurality of second openings have substantially the same shape.   3. The liquid crystal display device according to claim 2, wherein each of the plurality of second openings is longer in a long side direction than each of the plurality of first openings.   5. The device according to claim 1, wherein each of the plurality of first openings is unevenly arranged on the best viewing azimuth side relative to each of the plurality of second openings. Liquid crystal display device.   The liquid crystal display device according to claim 1, wherein each of the plurality of first openings and the plurality of second openings is periodically arranged.   The liquid crystal display device according to claim 1, wherein one of the plurality of second openings is disposed so as to be opposed to two or more of the plurality of first openings. .   The liquid crystal display device according to claim 1, wherein two or more of the plurality of second openings are disposed so as to be opposed to each of the plurality of first openings. The length of the short side orientation of each of the plurality of first openings and the plurality of second openings is 5 μm or more and 40 μm or less,
The length of the long side direction of each of the plurality of first openings and the plurality of second openings is longer than the length of the short side direction and is 20 μm or more and 300 μm or less. Liquid crystal display device.   The plurality of first openings are arranged such that a distance between edges of two first openings adjacent to each other is 10 μm to 100 μm, and the plurality of second openings includes two second openings adjacent to each other. The liquid crystal display device according to claim 1, wherein the distance between the edges of the portions is 10 μm or more and 100 μm or less. The other surface side of the first substrate is set as a display surface,
The plurality of first openings and the plurality of second openings each have a long side azimuth of approximately vertical azimuth, substantially horizontal azimuth on the display surface, or azimuth inclined by approximately 45 ° ± 10 ° from the vertical azimuth. The liquid crystal display device according to claim 2, wherein the liquid crystal display device is arranged according to any one of the above. A plurality of unit areas are provided in an effective display area where the first electrode and the second electrode overlap,
The liquid crystal display device according to claim 11, wherein a long side orientation of each of the plurality of first openings and the plurality of second openings is different for each of the plurality of unit regions.   The liquid crystal display device according to claim 12, wherein each of the plurality of unit regions is a region corresponding to a segment display unit or a dot matrix display unit.   The liquid crystal display device according to claim 12, wherein each of the plurality of unit regions is a region corresponding to one of subpixels obtained by further dividing one pixel in the dot matrix display unit. A first substrate having a first electrode on one side;
A second substrate having a second electrode on one side, the second substrate being disposed opposite to the first substrate so that the second electrode and the first electrode of the first substrate face each other;
A liquid crystal layer provided between the first substrate and the second substrate;
Including
The first electrode has a plurality of first protrusions that are spaced apart from each other,
The second electrode has a plurality of second protrusions provided separately from each other,
Each of the plurality of first protrusions is a liquid crystal display device arranged so that at least a part thereof overlaps any one of the plurality of second protrusions in plan view. A first substrate having a first electrode on one side;
A second substrate having a second electrode on one side, the second substrate being disposed opposite to the first substrate so that the second electrode and the first electrode of the first substrate face each other;
A liquid crystal layer provided between the first substrate and the second substrate;
Including
The first electrode has a plurality of protrusions provided separately from each other,
The second electrode has a plurality of openings each provided in a rectangular shape,
Each of the plurality of protrusions is a liquid crystal display device arranged so that at least a part thereof overlaps any one of the plurality of openings in plan view. A first substrate having a first electrode on one side;
A second substrate having a second electrode on one side, the second substrate being disposed opposite to the first substrate so that the second electrode and the first electrode of the first substrate face each other;
A liquid crystal layer provided between the first substrate and the second substrate;
Including
The first electrode has a plurality of first openings each provided in a rectangular shape and a plurality of first protrusions provided separately from each other,
The second electrode has a plurality of second openings each provided in a rectangular shape, and a plurality of second protrusions provided separately from each other,
Each of the plurality of first protrusions is arranged so that at least a portion thereof overlaps any one of the plurality of second openings in plan view,
Each of the plurality of second protrusions is a liquid crystal display device arranged so that at least a part thereof overlaps any one of the plurality of first openings in plan view.