JP2006119405A - Liquid crystal display device and electronic appliance - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a construction with which alignment controllability of a liquid crystal is further heightened by a method different from a conventional method, in a liquid crystal display device equipped with an alignment controlling structure. <P>SOLUTION: The liquid crystal display device comprises a plurality of pixel regions constructed by arranging the liquid crystal 130, which is aligned in a direction substantially vertical to inside faces of a pair of substrates 110, 120 in the case with no electric field applied thereto, between the pair of substrates 110, 120, and is characterized by being equipped with a principal alignment controlling means 122a formed on the inside face of one of the substrate out of the pair of substrates inside the pixel region, and a plurality of auxiliary alignment controlling means 122b formed on the inside face of the one substrate or the other substrate inside the pixel region, arranged on the periphery of the principal alignment controlling means so as to be extended to a direction going away from the principal alignment controlling means, and having a width S2 less than a width W1 of the principal alignment controlling means. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a liquid crystal display device and an electronic apparatus, and more particularly to a vertical alignment mode liquid crystal display device in which liquid crystal is aligned substantially perpendicular to the inner surface of a substrate in the absence of an electric field.

  Conventional liquid crystal display devices generally have a cell structure in which liquid crystal is sealed between a pair of substrates, and are configured to perform display by controlling the alignment state of the liquid crystal by an electric field. Such a liquid crystal display device has a TN mode in which the alignment direction of the liquid crystal is twisted 90 degrees in the thickness direction of the liquid crystal layer when no electric field is applied, and the liquid crystal is aligned substantially perpendicular to the inner surface of the substrate when the electric field is applied. There are liquid crystal display devices and IPS mode liquid crystal display devices in which the alignment direction of the liquid crystals rotates on a plane parallel to the inner surface of the substrate in the presence or absence of an electric field, but there is a problem that the viewing angle is narrow in the TN mode. In the IPS mode, although a wide viewing angle can be secured, there are problems such as a slow response speed, insufficient light transmittance, and difficulty in manufacturing.

  Therefore, a VA (Vertical Aligned) mode liquid crystal display device has been developed as a method that can satisfy other characteristics while ensuring a wide viewing angle. This liquid crystal display device generally uses a liquid crystal having a negative dielectric anisotropy, and the liquid crystal is oriented substantially perpendicularly to the inner surface of the substrate in a state where no voltage is applied. It is configured to be oriented substantially parallel to the inner surface. The drawback of this VA mode liquid crystal display device is that it is difficult to control the direction in which the liquid crystal tilts when an electric field is applied. If the orientation in which the liquid crystal is tilted is biased, viewing angle dependence occurs. Therefore, an orientation control structure such as a projection or slit (electrode pattern opening) is usually formed on the inner surface of the substrate, and the orientation in which the liquid crystal is tilted by these orientation control structures Is configured so as not to be biased to reduce the viewing angle dependency (see, for example, Patent Document 1 below).

In addition, the pixel region is divided into a plurality of subdots, and the alignment control structure (protrusions and electrode openings) is provided for each subdot, thereby controlling the alignment state of the liquid crystal in the pixel by the alignment control structure. A method for improving the performance has also been proposed (see, for example, Patent Documents 2 and 3 below). In this structure, in addition to the above, the shape of the sub-dots can be rotated, such as a circle or square, to further improve the alignment controllability, and by adding a chiral agent to the liquid crystal, alignment defects (discrete) The occurrence of display defects such as roughness (spots whose display mode changes depending on the viewing angle) due to (nation) is prevented.
JP-A-11-258606 JP 2002-202511 A JP 2003-43525 A

  However, even in a VA mode liquid crystal display device in which an alignment control structure is provided for each sub-dot to improve alignment stability as described above, the liquid crystal alignment control is greatly influenced by the size of the protrusions or slits. When is small, the liquid crystal is easily twisted and disclination occurs randomly. This disclination causes problems such as display defects such as roughness, a decrease in response speed, and occurrence of afterimages. In particular, when the definition of the liquid crystal display device is low, the sub-dots are large, so that the alignment stability of the liquid crystal is lowered and disclination is likely to occur. The same applies to the case where the symmetry of the subdot is lowered. In addition, if the alignment stability is insufficient, there is a problem that the alignment is easily disturbed when an external force is applied to the liquid crystal display device, and that once it is disturbed, it is difficult to return to the original state.

  Therefore, the present invention solves the above-mentioned problems, and the problem is that in a liquid crystal display device having an alignment control structure, the liquid crystal alignment controllability can be further improved by a method different from the conventional method. Is to realize.

  In view of such a situation, the liquid crystal display device of the present invention has a plurality of pixels in which a liquid crystal aligned in a direction substantially perpendicular to the inner surface of the substrate is applied between a pair of substrates in the absence of an electric field. A liquid crystal display device comprising a region, wherein a main orientation control means formed on an inner surface of one of the pair of substrates in the pixel region, and the one substrate or the other of the one in the pixel region A plurality of auxiliary alignment controls formed on the inner surface of the substrate and extending in a direction away from the main alignment control means around the main alignment control means and having a width smaller than the width of the main alignment control means. And means.

  According to the present invention, when an electric field is applied, the liquid crystal is oriented toward the periphery using the main alignment control means as a nucleus. However, in the surrounding area, a plurality of auxiliary alignment control means narrower than the main alignment control means are mainly used. Since it extends in a direction away from the alignment control means, the liquid crystal is easily aligned along the auxiliary alignment control means, and as a result, the alignment state of the liquid crystal is stabilized even in a region away from the main alignment control means. It is possible to reduce the occurrence of linations, the reduction in response speed, the occurrence of afterimages, and the like, and it is possible to improve the resilience of the alignment state disturbance caused by the external force.

  In the present invention, it is preferable that the plurality of auxiliary orientation control means are arranged radially around the main orientation control means. According to this, when the voltage is applied, the liquid crystal is aligned radially around the main alignment control means, so that the viewing angle dependency of the liquid crystal display device can be efficiently reduced.

  In the present invention, it is preferable that the main alignment control unit and the auxiliary alignment control unit include an opening formed in an electrode for applying a voltage to the liquid crystal. Since the opening (slit) forms the edge of the electrode, the alignment direction of the liquid crystal can be regulated by an oblique electric field formed at the edge of the electrode. Further, the main alignment control means and the auxiliary alignment control means may be constituted by protrusions or depressions formed on the inner surface of the one substrate or the other substrate, in addition to the electrode openings. These protrusions and depressions can generate an oblique electric field similar to that described above depending on which protrusion or recess, and can determine the alignment direction of the liquid crystal, but achieve higher shape accuracy than the electrode opening. It is difficult to control the three-dimensional shape. In particular, in the case of forming a fine pattern, it is most preferable that it is constituted by an electrode opening because the most reliable and sufficient alignment control ability can be obtained. In the present invention, the main alignment control means and the auxiliary alignment control means may be different from each other among the above three specific configurations.

  In the present invention, the width of the auxiliary orientation control means is preferably in the range of 3 to 8 μm. The width of the auxiliary alignment control means is only required to be smaller than the width of the main alignment control means, and is otherwise not particularly limited. However, in a normal size liquid crystal display device, the width of the auxiliary alignment control means is within a range of 3 to 8 μm. If it exists, sufficient controllability of the alignment direction can be generated for the liquid crystal, and the occurrence of display defects in the vicinity of the auxiliary alignment control means can be suppressed. For example, if the width of the auxiliary alignment control means is less than 3 μm, the alignment stability of the liquid crystal along the direction in which the auxiliary alignment control means extends may be lowered. Conversely, if the width exceeds 8 μm, it is in the vicinity of the auxiliary alignment control means. The liquid crystal alignment is likely to be disturbed, and the transmittance may be reduced.

  In the present invention, it is preferable that an interval between the plurality of auxiliary orientation control means is in a range of 5 to 30 μm. The interval between the auxiliary alignment control means is not particularly limited. However, in a normal size liquid crystal display device, if the interval between the auxiliary alignment control means is within the range of 5 to 30 μm, the decrease in the light transmittance of the pixel region is suppressed. The liquid crystal present in the interval can be stably aligned along the direction in which the auxiliary alignment control means extends. For example, if the interval between the auxiliary alignment control means is less than 5 μm, the number of auxiliary alignment control means may be too large, and the light transmittance of the pixel region may decrease. Conversely, if it exceeds 30 μm, the alignment stability of the liquid crystal May be insufficient.

  In the present invention, it is preferable that the shape of an envelope connecting the tips of the auxiliary orientation control means and the outer edge shape of the pixel region are substantially similar. According to this, since the shape of the envelope connecting the tips of the auxiliary alignment control means is substantially similar to the outer edge shape of the pixel area, the variation in distance from the auxiliary alignment control means to the outer edge of the pixel area is reduced. Since it can reduce over the whole circumference | surroundings of a main orientation control means, a higher effect can be acquired.

  In the present invention, it is preferable that a plurality of sub-regions are formed in the pixel region, and the main orientation control means and the plurality of auxiliary orientation control means are provided for each sub-region. By providing a main alignment control means and a plurality of auxiliary alignment control means in each of the plurality of sub-regions configured in the pixel region, the sub-region can be provided with liquid crystal alignment stability regardless of the planar shape and dimensions of the pixel region. Since it is possible to achieve a mode suitable for enhancement, for example, a planar shape with high rotational symmetry, or a relatively small size, the above effect can be further enhanced.

  An electronic apparatus according to the present invention includes the liquid crystal display device according to any one of the above, and a control unit that controls the liquid crystal display device. The electronic apparatus according to the present invention includes the above-described liquid crystal display device, whereby an apparatus having a display screen with high display quality can be configured. Examples of the electronic device include a mobile phone, a portable information terminal, an electronic timepiece, and a personal computer.

  Next, embodiments of a liquid crystal display device and an electronic apparatus according to the present invention will be described in detail with reference to the accompanying drawings. Each embodiment described below is usually configured to have a panel structure in which a pair of substrates is basically bonded with a sealing material and liquid crystal is sealed between the substrates. Since this is a well-known and commonly used technique, detailed description is omitted, and FIGS. 1 to 5 shown below show only a portion corresponding to one pixel region formed in a plurality of arrays in the panel structure. Only to do. Each figure is merely schematic, and the dimensions of each part, including the size of the liquid crystal molecules, are drawn greatly different from the actual ones for convenience of illustration.

[First Embodiment]
FIG. 1 is a schematic configuration diagram showing a structure of a first embodiment of a liquid crystal display device according to the present invention. In FIG. 1, a vertical sectional view corresponding to one pixel region is drawn at the center, a plan view of the inner surface structure of the first substrate is drawn above the vertical sectional view, and a second view is shown below the vertical sectional view. A plan view of the internal structure of the substrate is depicted.

  The liquid crystal display device according to the present embodiment has a transmissive panel structure, and is similar to the first substrate 110 having the inner surface structure described later on the inner surface of the substrate 111 made of glass, plastics, or the like. 121 has a second substrate 120 having an inner surface structure to be described later on the inner surface of 121, and the first substrate 110 and the second substrate 120 are separated by a gap of about 1 to 10 μm via a sealing material or the like. The liquid crystal layer 130 is disposed between them so as to face each other. This embodiment is a so-called VA mode liquid crystal display device, and the liquid crystal layer 130 is a liquid crystal having negative dielectric anisotropy, and is composed of, for example, a negative type nematic liquid crystal. However, although different from the illustrated example, a liquid crystal having positive dielectric anisotropy can be used in an EOC (Electrically-induced Optical Compensation) system. A large number of liquid crystal molecules 131 are arranged in the liquid crystal layer 130 in a predetermined alignment state.

  A retardation plate (for example, a quarter-wave plate) 141 and a polarizing plate 143 are disposed on the outer surface of the substrate 111, and a retardation plate (a quarter-wave plate) 142 and a polarizing plate 144 are disposed on the outside of the substrate 121. Is done. It is preferable that the phase difference plates 141 and 142 have a wide band. Further, the phase difference plates may not be provided, or may be configured with a phase difference other than a quarter wavelength. On the other hand, the polarizing plates 141 and 143 are set so as to have a relationship (for example, a crossed Nicol arrangement) in which a transmitted light blocking state and a transmitting state of the liquid crystal layer 130 are obtained depending on whether or not an electric field is applied.

  In the first substrate 110, a signal line 112 made of metal or the like is provided on the inner surface of the substrate 111, and the signal line 112 is conductively connected to the contact portion 114 in the pixel region via the connection portion 113. In the illustrated example, these conductive connection structures are omitted, and actually, a switching element such as a TFT (thin film transistor) or a TFD (thin film diode) is formed in the connection portion 113, and a signal is transmitted via the switching element. A signal potential is supplied from the line 112 to the contact portion 114. In the case of a three-terminal element such as a TFT, a scanning line (not shown) is formed in a direction crossing the signal line 112, and the conduction state of the three-terminal element is controlled by the scanning potential of the scanning line. . In the case of a two-terminal element such as TFD, the conduction state of the two-terminal element is controlled by the signal potential of the signal line 112.

  An insulating film 115 is formed of a transparent insulator such as acrylic resin on the contact portion 114, and a contact hole 115a is formed in the insulating film 115. The insulating film 115 is usually patterned into a mode having the contact hole 115a by a photolithography technique using a photosensitive resin. A pixel electrode 116 is formed on the insulating film 115 by a transparent conductor such as ITO (indium tin oxide). The pixel electrode 116 is conductively connected to the contact portion 114 through the contact hole 115a. In order to reduce the parasitic capacitance between the signal line 112 and the pixel electrode 116, the insulating film 115 needs to be formed to a certain thickness, and is usually about 0.5 to 3.0 μm, typically 1. It is formed to a thickness of about 0 μm. By forming the insulating film 115, the outer edge of the pixel region defined by the pixel electrode 116 can be brought close to the formation portion of the signal line 112 (the signal line and the scanning line when the scanning line is also formed). As a result, it is possible to increase the aperture ratio of the liquid crystal display device and realize a bright display.

  A vertical alignment film 117 is formed on the pixel electrode 116. The vertical alignment film 117 has an initial alignment ability for aligning the liquid crystal molecules 131 of the liquid crystal layer 130 in a direction perpendicular to the inner surface of the substrate in the absence of an electric field. Here, the liquid crystal molecules 131 are not perfectly vertically aligned even when no electric field is applied, but are aligned slightly inclined. Usually, one having an orientation angle of 85 degrees or more with respect to the inner surface of the substrate is said to be in a substantially vertical orientation state.

  On the other hand, in the second substrate 120, a counter electrode 122 is formed of a transparent conductor such as ITO on the inner surface of the substrate 121, and a vertical alignment film 123 similar to the above is formed on the counter electrode 122. A well-known color filter structure (not shown) may be formed on the inner surface of the second substrate 120, and the counter electrode 122 may be formed on the color filter structure. This color filter structure may be provided on the first substrate 110. The counter electrode 122 is generally a full-surface electrode formed in the panel when the three-terminal element is provided, and is generally a strip-like strip electrode when the two-terminal element is provided. It is.

  The counter electrode 122 is provided with a main orientation control means 122 a provided in the central portion of the pixel region D and configured by an opening of the counter electrode 122. The main orientation control means 122a is constituted by an electrode opening in the illustrated example, but as a projection (may be a cone shape or a column shape) constituted by the electrode itself, a dielectric on the electrode, or an insulator under the electrode. It may be provided. Furthermore, it may be constituted by a depression opposite to the protrusion. In any case, the main alignment control means 122a has an alignment controllability that forms an oblique electric field in the pixel region D and controls the breakdown direction of the liquid crystal molecules 131 in the electric field application state. That is, the main alignment control means 122a functions as a nucleus that determines the alignment state of the liquid crystal molecules 131 in an electric field application state.

  However, when the main alignment control means 122a is a projection, it is difficult to form a fine pattern, the controllability of the three-dimensional shape is low, the liquid crystal alignment is easily disturbed, and the liquid crystal injection is hindered. Since there is a problem that the time becomes long, it is most desirable that the main orientation control means 122a is composed of electrode openings (slits) as in the illustrated example.

  In addition, the main orientation control means 122a is configured to have a horizontally long shape corresponding to a horizontally long pixel shape in the illustrated example, that is, a slit shape in the case of being configured with electrode openings as in the illustrated example. ing. The width W1 of the main alignment control means 122a is usually preferably about 5 to 30 μm in order to ensure the above-described alignment control function and reduce disturbance of the liquid crystal alignment by the main alignment control means 122a itself. It is desirable to be about ˜15 μm. For example, if the width W1 is too small, it is difficult to obtain the alignment control function, and if the width W1 is too large, the formation range of the main alignment control means 122a becomes large. The contrast is reduced due to the above.

  The planar shape of the main orientation control means 122a is arbitrary, and can be, for example, a circular shape or a polygonal shape in addition to the extended shape as described above. Here, for example, when the planar shape of the main orientation control means 122a is a circle, the width W1 is the diameter, and when the planar shape is a polygon, it is the length of a diagonal line connecting the farthest corners.

  In the present embodiment, a plurality of auxiliary orientation control means 122b having a shape extending in a direction away from the main orientation control means 122a is provided around the main orientation control means 122a. These auxiliary alignment control means 122b are configured to extend linearly toward the outer edge of the pixel region D so as to be separated from the main alignment control means 122a. In the illustrated example, since the auxiliary alignment control means 122b is connected to the main alignment control means 122a, the alignment state of the liquid crystal molecules 131 is reliably assisted including the vicinity of the main alignment control means 122a. It can be stabilized by the orientation control means 122b. However, the auxiliary orientation control means 122b may be provided in a state separated from the main orientation control means 122a.

  The width W2 of the auxiliary orientation control means 122b is smaller than the width W1 of the main orientation control means 122a. This is because the auxiliary alignment control unit 122b has a function of stabilizing the alignment direction of the liquid crystal molecules 131 in the electric field applied state along the direction in which the auxiliary alignment control unit 122b extends. If the width W2 is equal to or greater than the width W1, the electric field is greatly changed by the auxiliary alignment control means 122b and functions as the main alignment control means. Therefore, the alignment direction of the liquid crystal is centered on the auxiliary alignment control means 122b. The liquid crystal molecules 131 are easily aligned in the direction intersecting the extension direction of the auxiliary alignment control means 122b, and the display area and the contrast decrease due to the increase in the area of the portion functioning as the main alignment control means. It tends to occur. The auxiliary alignment control means 122b of this embodiment is for stabilizing the alignment direction of the liquid crystal molecules 131 substantially determined by the main alignment control means 122a. Basically, the alignment direction of the liquid crystal molecules 131 is the auxiliary alignment control means. The direction is along the extending direction of 122b.

  The width W2 of the auxiliary orientation control means 122b is required to be smaller than W1 as described above, and is not particularly limited, but is usually preferably about 3 to 8 μm. Below this range, it becomes difficult to obtain the effect of improving the stability of the alignment state of the liquid crystal, and when it exceeds the above range, the function as the auxiliary alignment control means is lowered and the transmittance is lowered.

  Although the auxiliary orientation control means 122b is configured by an electrode opening in the illustrated example, the auxiliary alignment control unit 122b is formed as a projection (which may be a cone shape or a column shape) formed of the electrode itself, a dielectric on the electrode, or an insulator under the electrode. It may be provided. Furthermore, it may be constituted by a depression opposite to the protrusion. In any case, the auxiliary alignment control unit 122b has a function of improving the alignment stability of the liquid crystal molecules 131 in the electric field application state along the alignment control direction by the main alignment control unit 122a. That is, the auxiliary alignment control means 122b functions as a guide structure that stabilizes the alignment state of the liquid crystal molecules 131 in an electric field application state.

  However, when the auxiliary alignment control means 122b is a projection, it is difficult to form a fine pattern, the controllability of the three-dimensional shape is low, the liquid crystal alignment is easily disturbed, and the liquid crystal injection is hindered. Since there is a problem that the time becomes long, it is most desirable that the auxiliary orientation control means 122b is constituted by an electrode opening (slit) as shown in the illustrated example.

  The auxiliary orientation control means 122b of this embodiment is preferably arranged radially around the main orientation control means 122a as in the illustrated example. In this way, the stability of the alignment state of the liquid crystal by the auxiliary alignment control means 122b can be ensured uniformly. The term “radial” as used herein means that the main orientation control means 122a is arranged almost uniformly around the main orientation control means 122a. However, in the case of the present invention, the auxiliary orientation control means 122b may be arranged in a bowl shape in a posture that extends in the direction orthogonal to the extension direction along the extension direction of the main orientation control means 122a.

  In the case of the present embodiment, the auxiliary alignment control unit 122b is formed on the same substrate 121 as the main alignment control unit 122a, but the main alignment control unit is formed on one substrate (for example, the first substrate 110). The auxiliary orientation control means may be formed on the other substrate (for example, the second substrate 120).

  The interval G2 between the auxiliary orientation control means 122b is preferably about 5 to 30 μm. If the gap G2 is too small, the number of auxiliary alignment control means 122b may increase, leading to a reduction in display quality (for example, a reduction in transmittance). If the gap G2 is too large, the stability of the alignment state of the liquid crystal may be reduced. It is because the function to maintain falls. This distance G2 is more preferably in the range of 10 to 25 μm. If the interval G2 is not uniform as shown in the figure, the average of all intervals may be set within the above range.

  The embodiment having the above-described configuration has the following operational effects. When only the main alignment control means is provided as in the conventional configuration, the width and length of the main alignment control means are restricted depending on the shape and dimensions of the pixel region D. This is because if the main alignment control means is enlarged, the alignment of the liquid crystal is disturbed in the constituent region of the main alignment control means, resulting in a decrease in transmittance. This effect becomes greater as the liquid crystal display device has a lower definition. In addition, when the planar shape of the pixel region D is rectangular as in the present embodiment, the alignment restriction by the main alignment control unit is not achieved in the outer edge portion separated from the main alignment control unit in the pixel region D, causing an alignment failure. It becomes easy.

  However, in the present embodiment, the alignment stability of the liquid crystal can be ensured by providing the plurality of auxiliary alignment control means 122b. That is, even if the central main alignment control means 122a is minimized, the alignment stability of the liquid crystal is maintained, and liquid crystal alignment defects are less likely to occur even in a region away from the main alignment control means 122a. Further, since the liquid crystal molecules 131 receive the alignment regulating force not only from the main alignment control means 122a but also from the auxiliary alignment control means 122b, the response speed is further improved.

  In addition, since the width W2 of the auxiliary alignment control unit 122b is smaller than that of the main alignment control unit 122a, even if the auxiliary alignment control unit 122b is provided, the alignment disorder of the liquid crystal molecules 131 hardly increases, and the main alignment of the same area is simply obtained. A much higher transmittance can be obtained as compared with the case where the control means is added. Accordingly, it is possible to realize a high display quality that is bright and capable of high-speed response while maintaining high orientation controllability and that does not cause an afterimage.

  The inventor prototyped the liquid crystal display device having the conventional structure in which only the main alignment control means 122a is formed and the liquid crystal display device of the present embodiment having the auxiliary alignment control means 122b in the same manner under other conditions. Compared. Here, the width W1 of the main orientation control means 122a is about 10 μm, and the width W2 of the auxiliary orientation control means is about 3 μm. At this time, the transmittance of the liquid crystal display device of the conventional configuration is 8%, and in the present embodiment, it is 7.5%, and the decrease in the transmittance is suppressed to be extremely small. In addition, the response speed of the conventional structure was 48.6 msec, but in this embodiment, the response speed was significantly increased to 41.2 msec. Further, with regard to the disturbance of the orientation when an external force is applied to the panel, there was a tendency for the disturbance to remain to some extent in the conventional structure, but in this embodiment, the disturbance disappeared instantaneously and returned to the original state.

  Further, in the conventional structure, when the width W1 of the main alignment control means 122a is 8 μm, disorder of alignment occurs at the outer edge portion of the pixel region D, and the transmittance starts to decrease. When the width W1 is 5 μm, the radial alignment is lost. The transmittance also deviated from the practical range, but in this embodiment, when the width W1 was 8 μm, alignment defects hardly occurred, and it was confirmed that the width W1 was within the practical range even when the width W1 was less than 8 μm.

[Second Embodiment]
Next, a second embodiment according to the present invention will be described with reference to FIG. Since this embodiment has the same basic structure as the first embodiment, the same reference numerals are given to the same parts, and the description thereof is omitted. In this embodiment, a reflective region is formed in a part of a pixel region to configure a transmissive display / reflective display combined type (semi-transmissive reflective type) liquid crystal display device.

  As shown in FIG. 2, the transmissive region T has the same cross-sectional structure as that of the first embodiment, and in the reflective region R, a reflective film 124 is formed on the inner surface of the second substrate 120 ′. The reflective film 124 is made of, for example, a metal film such as aluminum, silver, or chromium, and is disposed between the substrate 121 and the counter electrode 122 in the illustrated example. However, this reflective film may be configured as a reflective electrode that also serves as a counter electrode. A base film 125 for reducing the thickness of the liquid crystal layer 130 is formed below the reflective film 124. The base film 125 is preferably made of an insulator such as an insulating resin. As a result, the thickness of the liquid crystal layer 130 is reduced by the thickness of the base film 125. This is because the transmitted light constituting the transmissive display passes through the liquid crystal layer 130 only once, whereas the external light constituting the reflective display passes through the liquid crystal layer 130 twice, so the thickness of the liquid crystal layer 130 Is the same in the transmissive region T and the reflective region R, the reflected light constituting the reflective display receives a double birefringence effect from the liquid crystal layer 130 as compared with the transmitted light constituting the transmissive display. This is because it becomes difficult to optimize both the transparent display and the transparent display. For this reason, in this embodiment, the thickness of the liquid crystal layer 130 in the reflection region R is reduced in advance than that in the transmission region T, thereby reducing the difference in birefringence effect on reflected light and transmitted light. Therefore, the thickness of the liquid crystal layer 130 in the reflective region R is most desirably about half of the thickness of the liquid crystal layer 130 in the transmissive region T. The structure in which the thickness of the liquid crystal layer 130 in the reflective region R is smaller than the thickness of the liquid crystal layer 130 in the transmissive region T is the thickness of the insulating film 115 provided on the first substrate 110 instead of providing the base film 125. The present invention is not limited to the configuration of the illustrated example, and can be realized by changing the size.

  Further, a fine concavo-convex structure is provided on the surface of the base film 125, and the reflective film 124 is roughened to reflect this, so that the surface of the reflective film 124 becomes a light scattering reflective surface. It is desirable. As a result, it is possible to prevent illusion due to illumination light and reflection of the background when performing reflective display.

[Third Embodiment]
Next, a third embodiment of the liquid crystal display device according to the present invention will be described with reference to FIG. This embodiment also has basically the same structure as that of the first embodiment, and the same parts are denoted by the same reference numerals and the description thereof is omitted. Further, instead of the basic structure of the first embodiment, the following structure may be used based on the structure of the second embodiment.

  In this embodiment, the pixel electrode 116 ′ provided on the first substrate 110 ′ has a substantially similar outer edge shape to the envelope E connecting the tips of the auxiliary orientation control means 122 b provided on the second substrate 120. It differs from the above-mentioned embodiment by the point provided. That is, in the first embodiment, since the planar shape of the pixel region is a rectangle, the distance from the tip of the auxiliary orientation control unit 122b to the outer edge of the pixel region is increased at the corner of the pixel region. There is a possibility that orientation failure occurs near the portion. Therefore, in the present embodiment, the planar shape of the pixel electrode 116 ′ is made to have a shape in which the corners of the first embodiment are cut, and the display quality is affected by poor alignment by bringing the shape close to the shape of the envelope E. Reduced.

  In particular, if the auxiliary alignment control means 122b toward the corner of the pixel region is extended outward toward the corner, the interval between the auxiliary alignment control means 122b is widened, so the effect of ensuring the alignment stability of the liquid crystal is not expected much. However, in the present embodiment, since the pixel region is deformed so as to eliminate the corners, the alignment stability of the liquid crystal is not deteriorated due to an increase in the interval of the auxiliary alignment control means.

  In the present embodiment, the substantially similar shape means that it does not have to be a complete similar shape, and the pixels are arranged so as to reduce the variation over the entire circumference from the envelope E to the outer edge of the pixel region. It is only necessary that the planar shape of the region D is deformed with respect to a rectangle (square or rectangle) which is a general pixel shape.

[Fourth Embodiment]
Next, a fourth embodiment of the liquid crystal display device according to the present invention will be described with reference to FIG. This embodiment also has basically the same structure as that of the first embodiment, and the same parts are denoted by the same reference numerals and the description thereof is omitted. Further, instead of the basic structure of the first embodiment, the following structure may be used based on the structure of the second embodiment.

  In the present embodiment, the plurality of auxiliary alignment control means 122b ′ provided on the second substrate 120 ″ includes one that extends longer from the main alignment control means 122a to the corner of the pixel region. The auxiliary orientation control means extending toward the corner of the pixel region D may be disposed closer to the outer edge (that is, the corner), in other words, closer to the outer side, whereby the corner of the pixel region from the tip of the auxiliary orientation control means 122b ′. The distance to the portion is reduced, and it becomes possible to suppress alignment defects.

  Generally, in a portion where the distance from the main alignment control means 122a to the outer edge of the pixel region D is long, the tip of the auxiliary alignment control means 122b 'is provided so as to approach the outer edge side. At this time, the auxiliary orientation control means 122b 'may be formed long as shown by the solid line in the figure, or may be arranged on the outer side like the auxiliary orientation control means 122c shown by the dotted line in the figure. Further, the distance G2 ″ of the auxiliary orientation control means 122b ′ becomes larger as it extends outward. In this case, the auxiliary orientation control means 122c shown by the dotted line in the figure is arranged between the auxiliary orientation control means 122b ′. Since variations in the spacing between the control means can be reduced, fluctuations in the alignment stability of the liquid crystal can be suppressed, and the alignment stability of the liquid crystal can be ensured throughout.

[Fifth Embodiment]
Next, a fifth embodiment of the liquid crystal display device according to the present invention will be described with reference to FIG. This embodiment also has basically the same structure as that of the first embodiment, and the same parts are denoted by the same reference numerals and the description thereof is omitted. Further, instead of the basic structure of the first embodiment, the following structures may be configured based on the structures of the second to fourth embodiments.

  In the present embodiment, the pixel region D is divided into a plurality of sub-regions DA, DB, and DC, and a main alignment control unit 122a ″ and an auxiliary alignment control unit 122b ″ are provided in each of the sub regions. These sub-regions DA to DC are preferably configured so that rotational symmetry from the geometric center position is higher than that of the pixel region D. In the illustrated example, the pixel region D is substantially rectangular, whereas the sub-regions DA to DC are each formed in a square shape (more precisely, a rounded corner square). Of course, since the shape having the highest rotational symmetry is a circle, the planar shape of each sub-region may be a circle.

  The sub areas DA to DC of the present embodiment are configured by dividing the pixel electrode 116D provided on the first substrate 110D into three sub electrodes 116A, 116B, and 116C. These sub-electrodes 116A to 116C are conductively connected to each other so that the same potential is applied.

  In the second substrate 120D of the present embodiment, a main alignment control means 122a ″ is formed at the center of the sub-regions DA to DC, and a plurality of auxiliary alignment control means 122b ″ are provided around the main alignment control means 122a ″. The planar shape of the main orientation control means 122a ″ in the illustrated example is circular (or polygonal), and a plurality of auxiliary orientation control means 122b ″ are arranged radially around the main orientation control means 122a ″. However, the width of the auxiliary orientation control means 122b "is set smaller than the width of the main orientation control means 122a" (diameter or diagonal length in the illustrated example).

  In the present embodiment, the alignment stability of the liquid crystal in each sub-region can be further improved by dividing the pixel region D into a plurality of sub-regions DA to DC. That is, in this embodiment, the alignment control distance of the liquid crystal is smaller than that of the previous embodiment, and the symmetry of the alignment control range is also increased, so that the alignment stability of the liquid crystal can be greatly improved. . Further, since the alignment stability is improved by providing the auxiliary alignment control means 122b ″ as compared with the liquid crystal display device divided into the sub-regions of the conventional structure, it is bright, responds at high speed, and has a high display quality with little afterimage. Can be realized.

[Sixth Embodiment]
Finally, an electronic apparatus equipped with the electro-optical device according to the invention will be described with reference to FIGS. In this embodiment, an electronic apparatus including the liquid crystal display device 100 according to any one of the first to fifth embodiments described above as a display unit will be described.

  FIG. 6 is a schematic configuration diagram illustrating an overall configuration of a control system (display control system) for the liquid crystal display device 100 in the electronic apparatus of the present embodiment. The electronic device shown here includes a display control circuit 290 including a display information output source 291, a display information processing circuit 292, a power supply circuit 293, a timing generator 294, and a light source control circuit 295. Further, the liquid crystal display device 100 is provided with a panel structure 100P having the above-described configuration, a drive circuit 100D for driving the panel structure 100P, and a backlight 130 including a light source 131 and a light guide plate 132. The drive circuit 100D is composed of electronic components (such as a semiconductor IC) that are directly mounted on the panel structure 100P. However, in addition to the above-described aspect, the drive circuit 100D may be a circuit pattern formed on the substrate surface of the panel structure 100P, or a semiconductor IC chip mounted on a circuit board conductively connected to the panel structure 100P or It can also be configured by a circuit pattern or the like.

  The display information output source 291 includes a memory such as a ROM (Read Only Memory) or a RAM (Random Access Memory), a storage unit such as a magnetic recording disk or an optical recording disk, and a tuning circuit that tunes and outputs a digital image signal. The display information is supplied to the display information processing circuit 292 in the form of an image signal or the like of a predetermined format based on various clock signals generated by the timing generator 294.

  The display information processing circuit 292 includes various known circuits such as a serial-parallel conversion circuit, an amplification / inversion circuit, a rotation circuit, a gamma correction circuit, and a clamp circuit, and executes processing of input display information to obtain image information. Are supplied to the driving circuit 100D together with the clock signal CLK. The drive circuit 100D includes a scanning line drive circuit, a signal line drive circuit, and an inspection circuit. The power supply circuit 293 supplies a predetermined voltage to each of the above-described components.

  The light source control circuit 295 supplies power supplied from the power supply circuit 293 to the light source 131 of the backlight 130 based on a control signal introduced from the outside. The light emitted from the light source 131 is incident on the light guide plate 132 and irradiated from the light guide plate 132 to the panel structure. The light source control circuit 295 controls lighting / non-lighting of the light source 131 according to the control signal. It is also possible to control the luminance of each light source.

  FIG. 7 shows an appearance of a mobile phone which is an embodiment of the electronic apparatus according to the present invention. The electronic device 1000 includes an operation unit 1001 and a display unit 1002, and a circuit board 1003 is disposed inside a housing of the display unit 1002. The liquid crystal display device 100 is mounted on the circuit board 1003. And it is comprised so that the display area of the said panel structure 100P can be visually recognized in the surface of the display part 1002. FIG.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit or idea of the invention which can be read from the claims and the entire specification, and a liquid crystal display device with such a change Is also included in the technical scope of the present invention. For example, in the above embodiment, the active matrix type liquid crystal display device provided with switching elements such as TFT and TFD has been described. However, the present invention is a device configuration having no switching elements, for example, a passive matrix type device. It is also possible to apply to the configuration.

The inner surface figure of the 1st board | substrate of 1st Embodiment, the longitudinal cross-sectional view of a panel, and the inner surface figure of a 2nd board | substrate. The inner surface figure of the 1st board | substrate of 2nd Embodiment, the longitudinal cross-sectional view of a panel, and the inner side figure of a 2nd board | substrate. The inner surface figure of the 1st board | substrate of 3rd Embodiment, the longitudinal cross-sectional view of a panel, and the inner side figure of a 2nd board | substrate. The inner surface figure of the 1st board | substrate of 4th Embodiment, the longitudinal cross-sectional view of a panel, and the inner surface figure of a 2nd board | substrate. The inner surface figure of the 1st board | substrate of 5th Embodiment, the longitudinal cross-sectional view of a panel, and the inner surface figure of a 2nd board | substrate. The schematic block diagram of 6th Embodiment. The schematic perspective view of 7th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Liquid crystal display device 110 ... 1st board | substrate, 111 ... Board | substrate, 112 ... Signal line, 113 ... Connection part, 114 ... Contact part, 115 ... Insulating film, 115a ... Contact hole, 116 ... Pixel electrode, 117 ... Vertical alignment Film 120, second substrate 121, substrate 122, counter electrode 122a, main alignment control means 122b, auxiliary alignment control means 123, vertical alignment film, 100P, panel structure, 100D, drive circuit, 130, back Light, 290 ... Display control circuit, 1000 ... Electronic equipment (cell phone)

Claims (8)

A liquid crystal display device in which a plurality of pixel regions are configured by arranging liquid crystal aligned in a direction substantially perpendicular to the inner surface of a substrate in a state where no electric field is applied between a pair of substrates,
Main orientation control means formed on the inner surface of one of the pair of substrates in the pixel region;
The main alignment control means is formed on an inner surface of the one substrate or the other substrate in the pixel region, and is provided to extend in a direction away from the main alignment control means around the main alignment control means. A plurality of auxiliary orientation control means having a width smaller than the width of
A liquid crystal display device comprising:   The liquid crystal display device according to claim 1, wherein the plurality of auxiliary alignment control means are arranged radially around the main alignment control means.   3. The liquid crystal display device according to claim 1, wherein the main alignment control unit and the auxiliary alignment control unit include an opening formed in an electrode for applying a voltage to the liquid crystal. .   4. The liquid crystal display device according to claim 1, wherein a width of the auxiliary alignment control means is in a range of 3 to 8 μm.   5. The liquid crystal display device according to claim 1, wherein an interval between the plurality of auxiliary alignment control means is in a range of 5 to 30 μm.   6. The liquid crystal according to claim 1, wherein the shape of an envelope connecting the tips of the auxiliary orientation control means is substantially similar to an outer edge shape of the pixel region. Display device.   7. A plurality of sub-regions are formed in the pixel region, and the main orientation control means and the plurality of auxiliary orientation control means are provided for each of the sub-regions. The liquid crystal display device according to item. An electronic apparatus comprising: the liquid crystal display device according to claim 1; and a control unit that controls the liquid crystal display device.

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