JP4506362B2 - Liquid crystal display device, electronic equipment - Google Patents

Description

  The present invention relates to a liquid crystal display device and an electronic apparatus, and more particularly, in a transflective color liquid crystal display device using a vertically aligned liquid crystal, the same high brightness and wide field of view in the reflective mode as in the transmissive mode. The present invention relates to a technique capable of obtaining a square display.

  As a liquid crystal display device, a transflective liquid crystal display device having both a reflection mode and a transmission mode is known. In such a transflective liquid crystal display device, a liquid crystal layer is sandwiched between an upper substrate and a lower substrate, and a reflective film in which a window for light transmission is formed on a metal film such as aluminum is disposed below. A substrate that is provided on the inner surface of the substrate and that functions as a transflective plate has been proposed. In this case, in the reflection mode, external light incident from the upper substrate side passes through the liquid crystal layer, is reflected by the reflective film on the inner surface of the lower substrate, passes through the liquid crystal layer again, and is emitted from the upper substrate side, contributing to display. To do. On the other hand, in the transmissive mode, light from the backlight incident from the lower substrate side passes through the liquid crystal layer from the window portion of the reflective film, and then is emitted to the outside from the upper substrate side, contributing to display. Accordingly, of the reflective film formation region, the region where the window is formed is the transmissive display region, and the other region is the reflective display region.

However, the conventional transflective liquid crystal device has a problem that the viewing angle in transmissive display is narrow. This is because a transflective plate is provided on the inner surface of the liquid crystal cell so that parallax does not occur, and there is a limitation that reflection display must be performed with only one polarizing plate provided on the viewer side. This is because the degree of freedom in design is small. In order to solve this problem, Jisaki et al. Proposed a new liquid crystal display device using vertically aligned liquid crystal in Non-Patent Document 1 below. The characteristics are the following three.
(1) Employs a “VA (Vertical Alignment) mode” in which a liquid crystal having a negative dielectric anisotropy is aligned perpendicularly to a substrate, and this is defeated by applying a voltage.
(2) A “multi-gap structure” is employed in which the liquid crystal layer thickness (cell gap) is different between the transmissive display area and the reflective display area (refer to, for example, Patent Document 1).
(3) The transmissive display area is a regular octagon, and a projection is provided at the center of the transmissive display area on the counter substrate so that the liquid crystal tilts in eight directions within this area. In other words, “alignment division structure” is adopted.
Japanese Patent Laid-Open No. 11-242226 "Development of transflective LCD for high contrast and wide viewing angle by using homeotropic alignment", M. Jisaki et al., Asia Display / IDW'01, p.133-136 (2001)

When the orientation-divided VAN has poor orientation controllability, it has different transmittance and viewing angle characteristics for each pixel, resulting in a rough display defect. In the transmissive display mode, the light from the backlight passes through the panel only once and does not compensate itself. Therefore, this rough display defect becomes relatively conspicuous, and the alignment regulating means by the electrode slits or protrusions is indispensable. Can not. On the other hand, in the reflective display mode, the external light entering the panel passes through the panel twice and self-compensates, so even if there is some disturbance in the liquid crystal alignment, the display quality is not a big problem. In addition, since the thickness of the liquid crystal layer in the reflective display region is relatively small due to the multi-gap structure, the liquid crystal alignment is not easily disturbed. In addition, the core of the disclination can be fixed on the connecting portion by connecting the electrode portion for reflective display and the electrode portion for transmissive display by a thin conductive portion (connecting portion). By fixing the disclination nucleus in this way, the liquid crystal alignment in the reflective display area can be controlled to some extent, so that the reflective display area does not require strong alignment control means such as protrusions and electrode slits. . Furthermore, if there are irregularities for light scattering in the reflective display region, the irregularities contribute to the liquid crystal alignment to some extent, and the liquid crystal alignment can be prevented from being disturbed by a halftone or the like. However, since the alignment regulating force in such a reflective display region is weaker than the protrusions and electrode slits provided in the transmissive display region, if there is no other contrivance other than this, The core of the disclination formed on the surface may move, and a rough display defect may occur during reflection display. In view of this, a configuration in which an orientation regulating means such as a protrusion is provided also in the reflective display region can be considered, but in this case, a light loss is caused by the area of the protrusion or the like. In particular, since the area of the reflective display region is often set smaller than the area of the transmissive display region, the luminance is greatly reduced due to the loss of light compared to the case where protrusions are provided in the transmissive display region.
The present invention has been made in view of such circumstances, and provides a liquid crystal display device capable of sufficiently controlling the orientation of the reflective display region without impairing the brightness of the reflective display. An object of the present invention is to provide an electronic device having a liquid crystal display device with high visibility.

In order to solve the above problems, the liquid crystal display device of the present invention is a vertical alignment mode liquid crystal display device having a reflective display region and a transmissive display region in one dot region, and the liquid crystal layer has a dielectric The liquid crystal layer having a negative anisotropy is between the liquid crystal layer and at least one of the pair of substrates, and the liquid crystal layer thickness of the reflective display region is greater than the liquid crystal layer thickness of the transmissive display region. A liquid crystal layer thickness adjusting layer is provided, and the pair of substrates is provided with electrodes for driving the liquid crystal, and at least one of the electrodes of the pair of substrates is A plurality of island-shaped portions provided in the dot region, and a connecting portion that electrically connects the adjacent island-shaped portions to each other, and the plurality of island-shaped portions are connected to the transmissive display region. An integer number is arranged in each of the reflective display areas. The dimension of the connecting part is 8 μm or more and 20 μm or less in the direction extending in the arrangement direction of the island-like parts, and the dimension in the direction orthogonal to the arrangement direction of the island-like parts is 5 μm or more and 20 μm or less. It is characterized by being.
A liquid crystal display device of the present invention is a transflective liquid crystal display device having a multi-gap structure, and a vertical alignment mode, wherein an electrode in a dot region includes a plurality of island-shaped portions and the plurality of island-shaped portions. And a connecting portion for electrically connecting the two. In this way, the electrode in the dot region has a plurality of island-shaped portions, so that the tilt direction of the vertically aligned liquid crystal moves toward the center of the island-shaped portion due to the oblique electric field generated at the edge of the island-shaped portion when voltage is applied. As a result, a liquid crystal domain having a radial alignment state is formed in the planar region of each island-like portion. By forming a plurality of liquid crystal domains having a planar radial alignment state in the dot region in this way, uniform viewing angle characteristics can be obtained in each direction by each liquid crystal domain, and the boundary between the liquid crystal domains is adjacent islands. Since it is fixed to the boundary region of the shape portion, good display can be obtained without causing spot-like unevenness when the panel is perspective. Further, since structures such as protrusions are not arranged in the reflective display area, the display area is increased correspondingly, and a bright reflective display can be obtained. In the present invention, since the dimensions of the connecting portion of the island-shaped portion are set as described above, the core of the disclination is fixed on the connecting portion and does not move. For this reason, the rough display defect which arises when the said nucleus moves is improved, and a reflective display with sufficient visibility comes to be obtained.

In the liquid crystal display device of the present invention, a plurality of the connecting portions are provided between the adjacent island-shaped portions, and the plurality of connecting portions are the central portions of the adjacent island-shaped portions. It is preferable that they are arranged so as to be symmetric with respect to a line connecting the two.
According to this configuration, since the symmetry of the liquid crystal alignment is increased, a reflective display with better visibility can be obtained.

In the liquid crystal display device of the present invention, the other substrate facing the substrate on which the island-shaped portion is provided has a position of the liquid crystal at the time of electric field application at a position facing the island-shaped portion in the transmissive display region. It is preferable that an orientation regulating means for regulating the orientation state is provided. Here, the orientation regulating means may be an opening provided in the electrode of the other substrate or a protrusion made of a dielectric material provided on the electrode of the other substrate.
According to this configuration, by the alignment control action by the oblique electric field generated at the edge of the island-shaped part and the alignment control function by the alignment control means, the island-shaped part in the plane area (that is, in the display area) can be further improved. It becomes possible to control the alignment state of the liquid crystal. For this reason, even when the plane area of the island-shaped portion is relatively large, the orientation is hardly disturbed and a good display can be obtained.

In the liquid crystal display device of the present invention, the substrate provided with the island-shaped portion is provided with a switching element electrically connected to the island-shaped portion through a contact hole, and the contact hole and the It is preferable that they are arranged so as to overlap with the orientation regulating means in a plane.
According to this configuration, since the contact hole is provided to face the orientation regulating means such as the protrusion, the effective display area is not impaired by the contact hole.

In the liquid crystal display device of the present invention, it is preferable that the island-like portion has a substantially circular shape or a substantially regular polygonal shape in plan view.
In the present invention, the island-shaped portion is provided in order to obtain a radial liquid crystal alignment in the same plane region by an oblique electric field generated at the edge. Therefore, by applying each of the above shapes, a liquid crystal domain having the radial alignment state can be easily formed. From the viewpoint of uniform viewing angle characteristics, the island-like portion preferably has a shape having rotational symmetry with respect to the center of the surface, and preferably has a circular or regular polygonal planar shape.

The liquid crystal display device of the present invention is a vertical alignment mode liquid crystal display device having a liquid crystal layer sandwiched between a pair of substrates and having a reflective display region and a transmissive display region in one dot region, The liquid crystal layer is made of a liquid crystal having a negative dielectric anisotropy, and the liquid crystal layer thickness of the reflective display region is set to the transmissive display region between at least one of the pair of substrates and the liquid crystal layer. A liquid crystal layer thickness adjusting layer for reducing the thickness of the liquid crystal layer, and a protrusion made of a dielectric material is provided along an edge of the transmissive display region on at least one of the pair of substrates. The protrusion is formed in an open ring shape having a cut at the boundary between the reflective display region and the transmissive display region, and the protrusion has a width of 8 μm or more and 20 μm or less. the width of the slit is 5μm or less And wherein the at 20μm or less.
The liquid crystal display device of the present invention is a transflective, vertical alignment mode liquid crystal display device having a multi-gap structure, and controls the alignment of the liquid crystal in the dot region by protrusions. In the present invention, the outer periphery of the transmissive display area is surrounded by protrusions, and the protrusions are also arranged at the boundary between the reflective display area and the transmissive display area, so that the alignment regulating force by the protrusions greatly affects the reflective display area. be able to. For this reason, a bright display without a display defect can be obtained without providing an alignment regulating means such as a protrusion in the reflective display area. Further, in the present invention, since the cut is provided in the protrusion and the size of the cut is set as described above, the core of the disclination is fixed to the cut portion and does not move. For this reason, the rough display defect which arises when the said nucleus moves is improved, and a reflective display with sufficient visibility comes to be obtained.

In the liquid crystal display device of the present invention, the pair of substrates is provided with electrodes for driving the liquid crystal, and the other substrate facing the substrate provided with the protrusions is provided with the other substrate. A switching element electrically connected via a contact hole is provided on an electrode provided in the transmissive display region of the substrate, and the contact hole is disposed so as to overlap the projection in a plane. Is preferred.
According to this configuration, since the contact hole is provided to face the orientation regulating means such as the protrusion, the effective display area is not impaired by the contact hole.

An electronic apparatus according to the present invention includes the above-described liquid crystal display device according to the present invention.
According to this configuration, it is possible to provide an electronic apparatus including a display unit capable of displaying a wide viewing angle and high contrast in both reflection display and transmission display.

[First Embodiment]
[Liquid Crystal Display]
A first embodiment of the present invention will be described below with reference to FIGS.
The liquid crystal display device according to this embodiment is an example of an active matrix liquid crystal display device using a thin film diode (hereinafter abbreviated as TFD) as a switching element, and particularly capable of reflective display and transmissive display. This is an example of a transflective liquid crystal display device. In addition, in each figure, in order to make each layer and each member into a size that can be recognized on the drawing, the scale is varied for each layer and each member.

  FIG. 1 shows an equivalent circuit for the liquid crystal display device 100 of the present embodiment. The liquid crystal display device 100 includes a scanning signal driving circuit 110 and a data signal driving circuit 120. The liquid crystal display device 100 is provided with signal lines, that is, a plurality of scanning lines 13 and a plurality of data lines 9 intersecting with the scanning lines 13. The scanning lines 13 are driven by a scanning signal driving circuit 110, and the data lines 9 Are driven by the data signal driving circuit 120. In each pixel region 150, the TFD element 40 and the liquid crystal display element 160 (liquid crystal layer) are connected in series between the scanning line 13 and the data line 9. In FIG. 1, the TFD element 40 is connected to the scanning line 13 side and the liquid crystal display element 160 is connected to the data line 9 side. On the contrary, the TFD element 40 is connected to the data line 9 side and the liquid crystal display element 160 is connected to the data line 9 side. The display element 160 may be provided on the scanning line 13 side.

Next, the planar structure (pixel structure) of the electrodes of the liquid crystal display device 100 of the present embodiment will be described with reference to FIG.
As shown in FIG. 2, in the liquid crystal display device 100 of the present embodiment, pixel electrodes 31 connected to the scanning lines 13 via the TFD elements 40 are provided in a matrix, and the pixel electrodes 31 are perpendicular to the paper surface. Opposite electrodes 9 are provided in a strip shape (stripe shape). The counter electrode 9 is the data line described above, and has a stripe shape that intersects the scanning line 13. In the present embodiment, each region where each pixel electrode 31 is formed is one dot region, and a TFD element 40 is provided for each dot region arranged in a matrix, and display is possible for each dot region. It has a simple structure. In FIG. 2, each pixel electrode is illustrated in a substantially rectangular shape, but actually has a plurality of island portions and a connecting portion for connecting these island portions as will be described later.

Next, a pixel configuration of the liquid crystal display device 100 according to the present embodiment will be described with reference to FIGS. FIG. 3 is a schematic diagram illustrating a pixel configuration of the liquid crystal display device 100, particularly a planar configuration of the pixel electrode 31, and FIG. 4 is a schematic diagram illustrating a cross section taken along line AA ′ of FIG. In FIG. 4, the upper side in the drawing is the viewing side.
As shown in FIG. 2, the liquid crystal display device 100 according to the present embodiment has a dot region including a pixel electrode 31 inside a region surrounded by the data lines 9 and the scanning lines 13. . In this dot area, as shown in FIG. 3, one colored layer of different colors among the three primary colors is arranged corresponding to one dot area, and three dot areas (D1, D2, D3) are arranged. Thus, one pixel including red, green, and blue is formed.

  The pixel electrodes 31 provided in the dot regions D1 to D3 are divided into a plurality of (two in this embodiment) island-shaped portions (subpixels) 31a and 31b by slits formed in each dot region. The shaped parts are connected at the central part (connecting part 31c). Each of the island portions 31a and 31b constitutes sub-dot regions S1 and S2, and each of the dot regions D1, D2 and D3 is divided into two sub-dot regions S1 and S2. Each island-shaped part 31a, 31b and the connection part 31c which connects these island-shaped parts are integrally formed by transparent conductive films, such as ITO (indium tin oxide). The upper island portion 31a in the drawing is disposed in the formation region of the reflection film 80 partially provided in each dot region, and the remaining lower island portion 31b is the non-formation region of the reflection film 80. Is arranged. The planar region of the island-shaped portion 31a disposed in the formation region of the reflective film 80 is the reflective display region R in the present liquid crystal display device 100, and the remaining planar region of the lower island-shaped portion 31b is the transmissive display region T. Has been. The surface of the reflective film 80 is provided with an uneven shape, and reflected light is scattered by the unevenness, whereby a display with good visibility can be obtained. That is, the liquid crystal display device 100 of the present embodiment is a transflective liquid crystal display device including a reflective display region R that performs reflective display and a transmissive display region T that performs transmissive display in one dot region. Approximately 1/3 of the displayable area contributes to reflective display, and the remaining approximately 2/3 of the area contributes to transmissive display. In addition, although the shape of an island-shaped part is square shape or octagonal shape in FIG. 3, it is not restricted to this, For example, it can be set as a circular shape and another polygonal shape. In particular, from the viewpoint of uniform viewing angle characteristics, the island-shaped portion preferably has a shape having rotational symmetry with respect to the center of the surface, and preferably has a planar shape of a substantially circular shape or a substantially regular polygonal shape.

  In the present embodiment, the connecting portion 31c has a vertical dimension d1 extending in the arrangement direction (vertical direction in the figure) of the island-like portions 31a and 31b of 10 μm, and the arrangement direction of the island-like portions 31a and 31b. The horizontal dimension d2 orthogonal to is set to 10 μm. With such a dimensional shape, the disclination nucleus can be firmly fixed to the connecting portion 31c. When one dot is divided into a plurality of subdots as in the present embodiment, a portion (disclination) where the liquid crystal cannot be well aligned occurs at the boundary between these subdots. The disclination nucleus is captured in the region of the connecting portion 31c. However, if the capturing force is weak, the disclination nucleus may move in a halftone or the like, which may reduce visibility. The inventor investigated the relationship between the disclination capturing force in the region of the connecting portion 31 and the size of the connecting portion 31c, and obtained a size range in which good visibility was obtained. Table 1 summarizes the relationship between the dimensions d1 and d2 of the connecting portion 31c and the disclination capturing force (ease of movement of disclination). In this embodiment, when both the vertical dimension d1 and the horizontal dimension d2 are 10 μm, good visibility is obtained in both the reflective display and the transmissive display. However, the vertical dimension d1 and the horizontal dimension d1 are obtained. If the dimension d2 is within the range shown in the examples of Table 1, generally good visibility can be obtained. According to Table 1, the lower limit of the vertical dimension d1 is between 7 μm and 9 μm (generally 8 μm), and the upper limit is about 20 μm. The lower limit of the horizontal dimension d2 is about 5 μm, and the upper limit is about 20 μm. That is, if the vertical dimension d1 is 8 μm or more and 20 μm or less and the horizontal dimension d2 is 5 μm or more and 20 μm or less, generally good visibility can be obtained. For this reason, by defining the dimensions d1 and d2 of the connecting portion 31c within this range, the alignment state can be maintained well without providing the reflective display region R with alignment regulating means such as protrusions.

  The TFD element 40 is a switching element that connects the scanning line 13 and the pixel electrode 31, and is illustrated between the first metal film 41 extending along the scanning line 13 and the two second metal films 42 and 43. It has a structure in which a substantially insulating film is sandwiched. A first element portion 40 a is formed at the intersection of the second metal film 42 formed by branching the scanning line 13 and the first metal film 41, and the intersection of the first metal film 41 and the second metal film 43. The second element part 40b is formed in the part. The island portion 31b (pixel electrode 31) is connected to the second metal film 43 through the contact hole C. Since the TFD element 40 according to the present embodiment has a structure in which the two element portions 40a and 40b are connected in opposite directions, stable element characteristics can be obtained regardless of the polarity of the applied voltage. . The first metal film 41 is made of, for example, Ta (tantalum), and the insulating film is made of, for example, tantalum oxide. The second metal film 42 (scanning line 13) and the second metal film 43 are made of, for example, Cr (chromium).

  Next, referring to the cross-sectional structure shown in FIG. 4, the liquid crystal display device 100 includes an element substrate 10 and a counter substrate 25 disposed so as to face the element substrate 10, and an initial alignment state between these substrates is a vertical alignment state. A liquid crystal layer 50 made of liquid crystal having negative dielectric anisotropy is sandwiched. A backlight (not shown) having a light source, a reflector, a light guide plate, and the like is provided as illumination means outside the liquid crystal cell corresponding to the outer surface side of the counter substrate 10.

  The element substrate 25 has a substrate body 25A made of a translucent material such as quartz or glass as a base, and includes a scanning line 13, a TFD element 40, and the like (see FIG. 3) on the inner surface side of the substrate body 25A. An interlayer insulating film 15 is formed so as to cover the scanning lines 13 and the like, and a pixel electrode 31 is formed on the interlayer insulating film 15. A contact hole C (see FIG. 3) is formed in the interlayer insulating film 15, and the TFD element 40 and the island-shaped portion 31b (pixel electrode 31) are electrically connected through the contact hole C. Yes. Although not shown, a vertical alignment film such as polyimide is formed so as to cover the pixel electrode 31 and the interlayer insulating film 15, and the initial alignment of the liquid crystal molecules is aligned perpendicular to the substrate surface. A phase difference plate 36 and a polarizing plate 37 are sequentially stacked on the outer surface side of the substrate body 25A. The TFD element 40 shown in FIG. 3 is provided between the interlayer insulating film 15 and the substrate body 25A.

  The counter substrate 10 has a substrate body 10A made of a translucent material such as quartz or glass as a base, and a metal film having a high reflectance such as Al (aluminum) or Ag (silver) is formed on the inner surface side of the substrate body 10A. A reflective film 80 made of is partially formed through an insulating film (not shown). This insulating film has an uneven shape on its surface, and the surface of the reflective film 80 has an uneven portion following the uneven shape. Since the reflected light is scattered by such irregularities, the viewing angle characteristics of the reflective display are improved, and good visibility can be obtained. A color filter (color filter layer) 22 is provided across the reflective display region R and the transmissive display region T on the reflective film 80 in the dot region and on the substrate body 10A. The color filter 22 is composed of a plurality of types of color filters (colored layers) having different colors, and a light shielding layer BM (black matrix) made of black resin or the like between the color filters constituting the color filter layer 22 as necessary. ) Is arranged.

  An insulating film 81 is selectively formed on the inner surface side of the color filter 22 corresponding to the reflective display region R. As described above, the insulating film 81 partially formed in the dot region makes the thickness of the liquid crystal layer 50 different between the reflective display region R and the transmissive display region T. The insulating film 81 is formed using an organic material film such as an acrylic resin. The insulating film 81 is formed to have a thickness of, for example, about 2 μm ± 1 μm. The thickness of the liquid crystal layer 50 where the insulating film 81 does not exist is about 2 μm to 6 μm, and the thickness of the liquid crystal layer 50 in the reflective display region R is transmissive. This is about half the thickness of the liquid crystal layer 50 in the display region T. That is, the insulating film 81 functions as a liquid crystal layer thickness adjusting layer that varies the thickness of the liquid crystal layer 50 in the reflective display region R and the transmissive display region T according to its own film thickness, thereby realizing a multi-gap structure. It has become. The liquid crystal display device 100 of the present example can display a bright and high-contrast display with such a configuration.

  Further, the counter electrode 9 is formed on the inner surface side of the substrate body 25 </ b> A so as to cover the surfaces of the color filter 22 and the insulating film 81. The counter electrode 9 is a striped transparent conductive film made of ITO or the like, and an opening (electrode slit) 9A having a hexagonal shape in a plan view is provided at a position facing the central portion of the island portion 31b in the counter electrode 9. It has been. The opening 9A functions as an alignment regulating means for controlling the tilt direction of the liquid crystal molecules when a voltage is applied. When the opening 9A is provided in the counter electrode 9 in this manner, an oblique electric field is generated around the opening 9A along the periphery of the island-shaped portion 31b facing the opening 9A from the opening 9A. Therefore, as shown in FIG. 3, the liquid crystal molecules 51 fall radially about the opening 9 </ b> A, and the liquid crystal molecules 51 are aligned radially around the center. Therefore, in the liquid crystal display device 100 of the present embodiment, the director of the liquid crystal molecules 51 faces in all directions when a voltage is applied, and a display with a very wide viewing angle is realized. Although not shown, a vertical alignment film is formed so as to cover the counter electrode 9 and the color filter 22, and the initial alignment of the liquid crystal molecules 51 is aligned perpendicular to the substrate surface. A phase difference plate 16 and a polarizing plate 17 are laminated on the outer surface side of the substrate body 10A.

  As described above, according to the liquid crystal display device 100 of the present embodiment, since the multi-gap structure in which the insulating film 81 for adjusting the liquid crystal layer thickness is partially provided in the dot area is employed, the transmissive display area The retardation of the liquid crystal layer 50 can be made uniform between T and the reflective display region R, and high contrast display can be obtained in both transmissive display and reflective display. Further, the pixel electrode 31 is divided into a plurality of island-shaped portions 31a and 31b, and the electrode slit 9A is provided corresponding to the central portion of the island-shaped portion 31b. In the region, the electrodes are radially oriented around the electrode slit 9A, and a display with a wide viewing angle is realized. In the present embodiment, since the dimensional shape of the connecting portion 31c is defined as described above, the core of the disclination is fixed on the connecting portion 31c and does not move. For this reason, the rough display defect which arises when the said nucleus moves is improved, and a reflective display with sufficient visibility comes to be obtained. In this configuration, since structures such as protrusions are not arranged in the reflective display area, the display area is increased correspondingly and a bright reflective display can be obtained.

[Second Embodiment]
Hereinafter, a second embodiment of the present invention will be described with reference to FIGS.
FIG. 5 shows a plan view of one pixel in the liquid crystal display device of the present embodiment, and is a schematic view corresponding to FIG. 3 of the first embodiment. FIG. 6 is a schematic diagram showing a BB ′ cross section of FIG. 5 and corresponds to FIG. 4 of the first embodiment. In FIG. 6, the upper side in the drawing is the viewing side. The basic configuration of the liquid crystal display device of this embodiment is the same as that of the first embodiment, except that the pixel electrode is not divided into island-shaped portions and the pixel electrode in the reflective display region is light reflective. These are only the point formed by the conductive material and the point that the orientation regulating means of the transmissive display region is constituted by the protrusion and the electrode slit. Therefore, in FIGS. 5 and 6, the same components as those in FIGS. 3 and 4 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 5, the pixel electrodes 31 provided in the dot regions D <b> 1 to D <b> 3 in the present embodiment are configured as substantially rectangular electrodes that straddle the reflective display region R and the transmissive display region T. Of the pixel electrode 31, an upper electrode portion 31 a in the drawing is formed of a light reflective metal film such as Al (aluminum) or Ag (silver) or a transparent conductive film such as ITO (indium tin oxide). It consists of a laminated film. The electrode portion 31a functions as a reflective electrode, and a region where the electrode portion 31a is formed becomes a reflective display region R. The surface of the electrode portion 31a is provided with a concavo-convex shape, and the reflected light is scattered by the concavo-convex, whereby a display with good visibility can be obtained. Further, the lower electrode portion 31b is made of a transparent conductive film such as ITO (indium tin oxide), and a region where the electrode portion 31b is formed becomes a transmissive display region T. That is, the liquid crystal display device 200 of the present embodiment is a transflective liquid crystal display device including a reflective display region R that performs reflective display and a transmissive display region T that performs transmissive display within one dot region. Approximately 1/3 of the displayable area contributes to reflective display, and the remaining approximately 2/3 of the area contributes to transmissive display.

  Each pixel electrode 31 is provided with an opening (electrode slit) 31A at a position that is the central portion of the transmissive display region T, and on the opposite substrate side facing the pixel electrode 31 with the liquid crystal layer interposed therebetween. The protrusion 18 made of a dielectric is provided in an annular shape along the edge of the transmissive display region T. The protrusions 18 and the electrode slits 31A function as alignment regulating means for controlling the tilting direction of the liquid crystal molecules when a voltage is applied. When the opening 31A is provided in the pixel electrode 31 in this manner, an oblique electric field is generated perpendicular to the edge of the opening 31A around the opening 31A, and the liquid crystal molecules 51 are perpendicular to the outline of the opening 31A. Tilt in the direction. In the vicinity of the protrusion 18, the liquid crystal molecules 51 are aligned perpendicularly to the inclined surface of the protrusion 18 when no voltage is applied, and the liquid crystal molecules 51 are tilted outward from the protrusion 18 when a voltage is applied. The liquid crystal molecules 51 are aligned. Therefore, in the transmissive display region T, the director of the liquid crystal molecules 51 is directed in all directions when a voltage is applied, and a display with a very wide viewing angle is realized. Furthermore, since the protrusion 18 is also arranged at the boundary portion of the reflective display region R, the alignment regulating force by the protrusion 18 can be greatly exerted on the reflective display region R.

The protrusion 18 is formed in an open ring shape having a cut 18A at the boundary between the reflective display region R and the transmissive display region T, and the dimension of the protrusion 18 is the width d3 of the protrusion 18 (of the electrode portions 31a and 31b). The vertical dimension of the cut line 18A extending in the arrangement direction is set to 10 μm, and the width d4 of the cut line 18A (the horizontal dimension orthogonal to the arrangement direction of the electrode portions 31a and 31b) is set to 12 μm. By adopting such a dimensional shape, it becomes possible to firmly fix the disclination nucleus to the cut portion 18A of the projection 18. When alignment is controlled by providing protrusions around the transmissive display region T as in the present embodiment, a portion where the liquid crystal cannot be aligned well (disclination) at the boundary between the transmissive display region T and the reflective display region R Will occur.
The disclination nucleus is captured in the region of the cut 18A of the protrusion 18. However, if the capturing force is weak, the disclination nucleus may move in a halftone or the like, which may reduce visibility. The inventor investigated the relationship between the disclination capturing force in the region of the cut 18A and the dimensions d3 and d4 of the cut 18A, and obtained a size range in which good visibility can be obtained.
Table 2 summarizes the relationship between the dimensions d3 and d4 of the cut 18A and the disclination capturing force (ease of movement of disclination). In this embodiment, when the dimension d3 in the vertical direction is 10 μm and the dimension d4 in the horizontal direction is 12 μm, good visibility is obtained in both the reflective display and the transmissive display. If the dimension d4 is within the range shown in the examples of Table 2, generally good visibility can be obtained. According to Table 2, the lower limit of the vertical dimension d3 is between 7 μm and 10 μm (generally 8 μm), and the upper limit is about 20 μm. The lower limit of the horizontal dimension d4 is about 5 μm, and the upper limit is about 20 μm. That is, if the vertical dimension d3 is 8 μm or more and 20 μm or less and the horizontal dimension d4 is 5 μm or more and 20 μm or less, generally good visibility can be obtained. For this reason, by defining the dimensions d3 and d4 of the protrusions 18 within this range, the alignment state can be maintained satisfactorily without providing an alignment regulating means such as protrusions in the reflective display region R.

Next, referring to the cross-sectional structure shown in FIG. 6, the liquid crystal display device 200 includes an element substrate 25 and a counter substrate 10 disposed to face the element substrate 25, and an initial alignment state between these substrates is a vertical alignment state. A liquid crystal layer 50 made of liquid crystal having negative dielectric anisotropy is sandwiched. A backlight (not shown) having a light source, a reflector, a light guide plate, and the like is provided as illumination means outside the liquid crystal cell corresponding to the outer surface side of the element substrate 25.

  The element substrate 25 has a substrate body 25A made of a translucent material such as quartz or glass as a base, and includes a scanning line 13, a TFD element 40, and the like (see FIG. 5) on the inner surface side of the substrate body 25A. An interlayer insulating film 15 is formed so as to cover the scanning lines 13 and the like, and a pixel electrode 31 is formed on the interlayer insulating film 15. The pixel electrode 31 includes a light reflective electrode portion 31 a provided in the reflective display region R and a light transparent electrode portion 31 b provided in the transmissive display region T. The electrode portion 31b disposed in the transmissive display region T is provided with an opening 31A at the center, and the tilt direction of the liquid crystal can be controlled by the action of an oblique electric field generated at the edge of the opening 31A. ing. A contact hole C (see FIG. 5) is formed in the interlayer insulating film 15 at a position facing the protrusion 18, and the TFD element 40 and the electrode portion 31 b (pixel electrode 31) are connected through the contact hole C. Electrically connected. Although not shown, a vertical alignment film such as polyimide is formed so as to cover the pixel electrode 31 and the interlayer insulating film 15, and the initial alignment of the liquid crystal molecules is aligned perpendicular to the substrate surface. A phase difference plate 36 and a polarizing plate 37 are sequentially stacked on the outer surface side of the substrate body 25A. 5 is provided between the interlayer insulating film 15 and the substrate body 25A.

  The counter substrate 10 has a substrate body 10A made of a translucent material such as quartz or glass as a base, and a color filter (color filter) is formed on the inner surface side of the substrate body 10A across the reflective display region R and the transmissive display region T. Layer) 22 is provided. The color filter 22 is composed of a plurality of types of color filters (colored layers) having different colors, and a light shielding layer BM (black matrix) made of black resin or the like between the color filters constituting the color filter layer 22 as necessary. ) Is arranged. An insulating film 81 is selectively formed on the inner surface side of the color filter 22 corresponding to the reflective display region R. As described above, the insulating film 81 partially formed in the dot region makes the thickness of the liquid crystal layer 50 different between the reflective display region R and the transmissive display region T. The insulating film 81 is formed using an organic material film such as an acrylic resin. The insulating film 81 is formed to have a thickness of, for example, about 2 μm ± 1 μm. The thickness of the liquid crystal layer 50 where the insulating film 81 does not exist is about 2 μm to 6 μm, and the thickness of the liquid crystal layer 50 in the reflective display region R is transmissive. This is about half the thickness of the liquid crystal layer 50 in the display region T. That is, the insulating film 81 functions as a liquid crystal layer thickness adjusting layer that varies the thickness of the liquid crystal layer 50 in the reflective display region R and the transmissive display region T according to its own film thickness, thereby realizing a multi-gap structure. It has become. The liquid crystal display device 200 of this example is configured so that a bright and high-contrast display can be obtained.

Further, the counter electrode 9 is formed on the inner surface side of the substrate body 10 </ b> A so as to cover the surfaces of the color filter 22 and the insulating film 81. The counter electrode 9 is a striped transparent conductive film made of ITO or the like, and an annular protrusion 18 made of a dielectric material is disposed on the counter electrode 9 along the edge of the transmissive display region T. As described above, the protrusion 18 constitutes an alignment regulating means for controlling the alignment of the transmissive display region T together with the electrode slit 31A on the element substrate side. Further, this alignment regulating force can be applied to the reflective display region R by the protrusions 18 arranged at the boundary with the reflective display region R. Further, the protrusion 18 is provided with a cut 18A (see FIG. 5) having the above-described dimensions at the boundary between the reflective display region R and the transmissive display region T, and the disclination is formed in the region where the cut 18A is formed. Can be fixed. Although not shown, a vertical alignment film is formed so as to cover the counter electrode 9 and the color filter 22, and the initial alignment of the liquid crystal molecules 51 is aligned perpendicular to the substrate surface. A phase difference plate 16 and a polarizing plate 17 are laminated on the outer surface side of the substrate body 10A.

  As described above, since the multi-gap structure is also adopted in this embodiment, a high-contrast display can be obtained in both the reflective display and the transmissive display. In the present embodiment, since the size and shape of the cut 18A of the projection 18 provided at the boundary between the reflective display region R and the transmissive display region T are defined as described above, the core of the disclination is the boundary of the cut 18A. It is fixed to the formation area and does not move. For this reason, the rough display defect which arises when the said nucleus moves is improved, and a reflective display with sufficient visibility comes to be obtained. In this configuration, since structures such as protrusions are not arranged in the reflective display area, the display area is increased correspondingly and a bright reflective display can be obtained. Further, in the present embodiment, the protrusion 18 and the contact hole C are arranged so as to overlap in a planar manner, so that light leakage caused by disclination occurring in the contact hole portion can be blocked.

[Third Embodiment]
Hereinafter, a third embodiment of the present invention will be described with reference to FIGS.
FIG. 7 shows a plan view of one pixel in the liquid crystal display device of the present embodiment, and is a schematic view corresponding to FIG. 3 of the first embodiment. FIG. 8 is a schematic diagram showing a cross section along DD ′ of FIG. 7 and corresponds to FIG. 4 of the first embodiment. In FIG. 8, the upper side in the drawing is the viewing side. The basic configuration of the liquid crystal display device of this embodiment is the same as that of the first embodiment, except that the number of connecting portions connecting island-like portions and the positions of contact holes connecting pixel electrodes and TFD elements are different. It is. Therefore, in FIG. 7 and FIG. 8, the same reference numerals are given to the same components as those in FIG. 3 and FIG.

  As shown in FIG. 7, the pixel electrodes 31 provided in the dot regions D1 to D3 in the present embodiment have a plurality of substantially the same size and shape due to the slits (openings 31B) formed in each dot region. It is divided into (in this embodiment, three) island-shaped portions (sub-pixels) 31a, 31b, 31b, and each island-shaped portion is connected at the central portion (connecting portion 31c). Each of the island portions 31a, 31b, and 31b constitute sub-dot regions S1, S2, and S3, and each of the dot regions D1, D2, and D3 is divided into three sub-dot regions S1, S2, and S3. ing. Each island-shaped part 31a, 31b, 31b and the connection part 31c which connects these island-shaped parts are integrally formed by transparent conductive films, such as ITO (indium tin oxide). The upper island portions 31a in the drawing are arranged in the formation region of the reflective film 80 partially provided in each dot region, and the remaining lower island portions 31b and 31b are non-reflective of the reflective film 80. Arranged in the formation area. The planar area of the island-shaped portion 31a arranged in the formation area of the reflective film 80 is the reflective display area R in the present liquid crystal display device 100, and the remaining planar areas of the lower island-shaped sections 31b and 31b are transmissive display areas. T. The surface of the reflective film 80 is provided with an uneven shape, and reflected light is scattered by the unevenness, whereby a display with good visibility can be obtained. That is, the liquid crystal display device 300 of the present embodiment is a transflective liquid crystal display device including a reflective display region R that performs reflective display and a transmissive display region T that performs transmissive display within one dot region. Approximately 1/3 of the displayable area contributes to reflective display, and the remaining approximately 2/3 of the area contributes to transmissive display.

  In the present embodiment, a plurality of connecting portions 31c are provided between adjacent island portions, and the plurality of connecting portions 31c include the adjacent island portions and the island portions. Are arranged so as to be symmetric with respect to a line connecting the central portions of the two. In the example of FIG. 7, two connecting portions 31 c are provided, one at each of the left and right ends of the island-shaped portion. The dimension of the connecting portion 31c is set such that the vertical dimension d1 extending in the arrangement direction (the vertical direction in the figure) of the island-shaped portions is 10 μm, and the horizontal dimension d2 orthogonal to the island-shaped arrangement direction is 10 μm. Has been. By adopting such a dimensional shape, the disclination nucleus can be firmly fixed to the connecting portion 31c (see Table 1). In addition, the dimension shape of the connection part 31c is not limited to this. If the vertical dimension d1 is not less than 8 μm and not more than 20 μm and the lateral dimension d2 is not less than 5 μm and not more than 20 μm, the disclination core can be firmly fixed and good visibility can be obtained. .

  The TFD element 40 is a switching element that connects the scanning line 13 and the pixel electrode 31, and is illustrated between the first metal film 41 extending along the scanning line 13 and the two second metal films 42 and 43. It has a structure in which a substantially insulating film is sandwiched. A first element portion 40 a is formed at the intersection of the second metal film 42 formed by branching the scanning line 13 and the first metal film 41, and the intersection of the first metal film 41 and the second metal film 43. The second element part 40b is formed in the part. The second metal film 43 of the second element portion 40b is connected to the routing wiring 46 directly or through a contact hole (not shown). The routing wiring 46 extends to the central portion of the island-shaped portion 31b, and the routing wiring 46 and the island-shaped portion 31b (pixel electrode 31) are connected through a contact hole C provided in the central portion of the island-shaped portion 31b. ) And are electrically connected. The leading end of the routing wiring 46 has a circular shape having a diameter slightly larger than the diameter of the contact hole C, and functions as a light shielding portion for blocking light leakage caused by disclination occurring in the contact hole portion.

Next, the sectional structure shown in FIG. 8, a liquid crystal display device 3 00, and a counter substrate 10 disposed opposite to the element substrate 25, the initial alignment state, vertical orientation state between the substrates A liquid crystal layer 50 made of a liquid crystal having negative dielectric anisotropy is sandwiched. A backlight (not shown) having a light source, a reflector, a light guide plate, and the like is provided as illumination means outside the liquid crystal cell corresponding to the outer surface side of the element substrate 25.

  The element substrate 25 has a substrate body 25A made of a translucent material such as quartz or glass as a base, and the scanning line 13, the TFD element 40, the lead wiring 46, etc. (see FIG. 7) are provided on the inner surface side of the substrate body 25A. I have. An interlayer insulating film 15 is formed so as to cover these scanning lines 13 and the like, and a pixel electrode 31 is formed on the interlayer insulating film 15. The pixel electrode 31 includes a light-reflecting electrode portion 31a provided in the reflective display region R, a light-transmitting electrode portions 31b and 31b provided in the transmissive display region T, and these electrode portions 31a, 31b, and 31b. It is comprised by the connection part 31c for connecting. The electrode portions 31b and 31b are made of a transparent conductive material such as ITO, and a connecting portion 31c is formed by providing slit-shaped openings (electrode slits) 31B in the rectangular electrode portions 31b and 31b. The opening 31B functions as an alignment regulating means for controlling the alignment of the liquid crystal. That is, the tilting direction of the liquid crystal can be controlled by the action of the oblique electric field generated at the side edge of the opening 31B. The size of the opening 31B is adjusted so that the dimension of the connecting part 31c is within the above-described dimension range, and the nucleus of the disclination can be fixed in the region where the connecting part 31c is formed. ing. In the interlayer insulating film 15, a contact hole C is formed at a position corresponding to the central portion of the island-shaped portion 31b. The contact hole is routed through the C to connect the wiring 46 (TFD element 40) and the island-shaped portion 31b. The (pixel electrode 31) is electrically connected. Although not shown, a vertical alignment film such as polyimide is formed so as to cover the pixel electrode 31 and the interlayer insulating film 15, and the initial alignment of the liquid crystal molecules is aligned perpendicular to the substrate surface. A phase difference plate 36 and a polarizing plate 37 are sequentially stacked on the outer surface side of the substrate body 25A. Note that the TFD element 40 shown in FIG. 7 is provided between the interlayer insulating film 15 and the substrate body 25A.

  The counter substrate 10 has a substrate body 10A made of a translucent material such as quartz or glass as a base, and a color filter (color filter) is formed on the inner surface side of the substrate body 10A across the reflective display region R and the transmissive display region T. Layer) 22 is provided. The color filter 22 is composed of a plurality of types of color filters (colored layers) having different colors, and a light shielding layer BM (black matrix) made of black resin or the like between the color filters constituting the color filter layer 22 as necessary. ) Is arranged. An insulating film 81 is selectively formed on the inner surface side of the color filter 22 corresponding to the reflective display region R. As described above, the insulating film 81 partially formed in the dot region makes the thickness of the liquid crystal layer 50 different between the reflective display region R and the transmissive display region T. The insulating film 81 is formed using an organic material film such as an acrylic resin. The insulating film 81 is formed to have a thickness of, for example, about 2 μm ± 1 μm. The thickness of the liquid crystal layer 50 where the insulating film 81 does not exist is about 2 μm to 6 μm, and the thickness of the liquid crystal layer 50 in the reflective display region R is transmissive. This is about half the thickness of the liquid crystal layer 50 in the display region T. That is, the insulating film 81 functions as a liquid crystal layer thickness adjusting layer that varies the thickness of the liquid crystal layer 50 in the reflective display region R and the transmissive display region T according to its own film thickness, thereby realizing a multi-gap structure. It has become. The liquid crystal display device 300 of this example is configured to obtain a bright and high-contrast display.

Further, the counter electrode 9 is formed on the inner surface side of the substrate body 10 </ b> A so as to cover the surfaces of the color filter 22 and the insulating film 81. The counter electrode 9 is a striped transparent conductive film made of ITO or the like, and a projection 18 made of a substantially conical dielectric is disposed at a position facing the island portions 31b, 31b on the counter electrode 9. ing. The protrusion 18 constitutes an alignment regulating means for controlling the alignment of the transmissive display region T together with the electrode slit 31B on the element substrate side. Although not shown, a vertical alignment film is formed so as to cover the counter electrode 9 and the color filter 22, and the initial alignment of the liquid crystal molecules 51 is aligned perpendicular to the substrate surface. A phase difference plate 16 and a polarizing plate 17 are laminated on the outer surface side of the substrate body 10A.

  As described above, since the multi-gap structure is also adopted in this embodiment, a high-contrast display can be obtained in both the reflective display and the transmissive display. In the present embodiment, the dimensions of the connecting portion 31c that connects the island-like portions 31a, 31b, and 31b are defined as described above. Therefore, the core of the disclination is fixed to the formation region of the connecting portion 31c. And never move. For this reason, the rough display defect which arises when the said nucleus moves is improved, and a reflective display with sufficient visibility comes to be obtained. In this configuration, since structures such as protrusions are not arranged in the reflective display area, the display area is increased correspondingly and a bright reflective display can be obtained.

[Fourth Embodiment]
The fourth embodiment of the present invention will be described below with reference to FIGS.
The liquid crystal display device of the present embodiment is an example of an active matrix type liquid crystal display device using a thin film transistor (hereinafter abbreviated as TFT) as a switching element, and particularly capable of reflective display and transmissive display. This is an example of a transflective liquid crystal display device. 9 to 11, the same components as those in FIGS. 1 to 4 are denoted by the same reference numerals, and detailed description thereof is omitted.

  FIG. 9 shows an equivalent circuit for the liquid crystal display device 400 of the present embodiment. As shown in FIG. 9, a pixel electrode 31 and a TFT 30 that is a switching element for controlling the pixel electrode 31 are formed on a plurality of dots arranged in a matrix constituting the image display area. The data line 6a to which the image signal is supplied is electrically connected to the source of the TFT 30. Image signals S1, S2,..., Sn to be written to the data line 6a are supplied line-sequentially in this order, or are supplied for each group to a plurality of adjacent data lines 6a. Further, the scanning line 3a is electrically connected to the gate of the TFT 30, and the scanning signals G1, G2,..., Gm are applied to the plurality of scanning lines 3a in a pulse-sequential manner at a predetermined timing. Further, the pixel electrode 31 is electrically connected to the drain of the TFT 30, and by turning on the TFT 30 as a switching element for a certain period, the image signals S1, S2,... Sn supplied from the data line 6a are predetermined. Write at the timing. Image signals S1, S2,..., Sn written to the liquid crystal via the pixel electrode 31 are held for a certain period with the common electrode formed on the counter substrate side. The liquid crystal modulates light by changing the orientation and order of the molecular assembly according to the applied voltage level, thereby enabling gradation display. Here, in order to prevent the held image signal from leaking, a storage capacitor 70 is added in parallel with the liquid crystal capacitor formed between the pixel electrode 31 and the common electrode. Reference numeral 3b denotes a capacity line.

Next, a pixel configuration of the liquid crystal display device 400 of the present embodiment will be described based on FIGS. 10 and 11. FIG. 10 shows a pixel configuration of the liquid crystal display device 400 , particularly a planar configuration of the pixel electrode 31, and is a schematic view corresponding to FIG. 3 of the first embodiment. Figure 11 is a schematic view showing the E-E 'cross section in FIG. 10 is a view corresponding to Figure 4 of the first embodiment. In FIG. 11, the upper side in the drawing is the viewing side.

As shown in FIG. 10, in the liquid crystal display device 400 of the present embodiment, a plan view surrounded by scanning lines 3a extending in parallel with each other and data lines 6a extending crossing these scanning lines. The rectangular regions are the dot regions D1 to D3, and one color filter (colored layer) of the three primary colors is formed corresponding to one dot region, and the three dot regions D1 to D3 have three colors. A pixel region including a filter is formed. Each of these color filters is formed in a stripe shape extending in the vertical direction in the drawing, and is formed across a plurality of dot regions in the extending direction, and is periodically arranged in the horizontal direction in the drawing. .

  The pixel electrodes 31 provided in the dot regions D1 to D3 are divided into a plurality (two in this embodiment) of island-like portions (subpixels) 31a and 31b by slits (opening portions 31B) formed in each dot region. It divides | segments and each island-like part is connected by the center part (connection part 31c). Each of the island portions 31a and 31b constitutes sub-dot regions S1 and S2, and each of the dot regions D1, D2 and D3 is divided into two sub-dot regions S1 and S2. The upper island-shaped portion 31a shown in the drawing is made of a light-reflective metal film such as Al (aluminum) or Ag (silver) or a laminated film of these metal films and a transparent conductive film such as ITO (indium tin oxide). The island portion 31a functions as a reflective electrode, and a region where the island portion 31a is formed becomes a reflective display region R. The surface of the reflective electrode is provided with a concavo-convex shape, and reflected light is scattered by the concavo-convex so that a display with good visibility can be obtained. The lower island portion 31b is made of a transparent conductive film such as ITO (indium tin oxide), and a region where the island portion 31b is formed becomes a transmissive display region T. That is, the liquid crystal display device 400 of the present embodiment is a transflective liquid crystal display device including a reflective display region R that performs reflective display and a transmissive display region T that performs transmissive display within one dot region. Approximately 1/3 of the displayable area contributes to reflective display, and the remaining approximately 2/3 of the area contributes to transmissive display.

  In the present embodiment, a plurality of connecting portions 31c are provided between the adjacent island-shaped portions 31a and the island-shaped portions 31b, and the plurality of connecting portions 31c include the adjacent island-shaped portions and the island-shaped portions. Are arranged so as to be symmetric with respect to a line connecting the central portions of the two. In the example of FIG. 10, a total of two connecting portions 31c are provided, one at each of the left and right ends of the island-shaped portion. The dimension of the connecting portion 31c is set such that the vertical dimension d1 extending in the arrangement direction (the vertical direction in the figure) of the island-shaped portions is 10 μm, and the horizontal dimension d2 orthogonal to the island-shaped arrangement direction is 10 μm. Has been. By adopting such a dimensional shape, the disclination nucleus can be firmly fixed to the connecting portion 31c (see Table 1). In addition, the dimension shape of the connection part 31c is not limited to this. If the vertical dimension d1 is not less than 8 μm and not more than 20 μm and the lateral dimension d2 is not less than 5 μm and not more than 20 μm, the disclination core can be firmly fixed and good visibility can be obtained. .

  Each pixel electrode 31 is provided with an opening (electrode slit) 31A at a position that is the central portion of the transmissive display region T, and on the opposite substrate side facing the pixel electrode 31 with the liquid crystal layer interposed therebetween. The protrusion 18 made of a dielectric is provided in an annular shape along the edge of the transmissive display region T. The protrusions 18 and the electrode slits 31A function as alignment regulating means for controlling the tilting direction of the liquid crystal molecules when a voltage is applied. When the opening 31A is provided in the pixel electrode 31 in this manner, an oblique electric field is generated perpendicular to the edge of the opening 31A around the opening 31A, and the liquid crystal molecules 51 are perpendicular to the outline of the opening 31A. Tilt in the direction. In the vicinity of the protrusion 18, the liquid crystal molecules 51 are aligned perpendicularly to the inclined surface of the protrusion 18 when no voltage is applied, and the liquid crystal molecules 51 are tilted outward from the protrusion 18 when a voltage is applied. The liquid crystal molecules 51 are aligned. Therefore, in the transmissive display region T, the director of the liquid crystal molecules 51 is directed in all directions when a voltage is applied, and a display with a very wide viewing angle is realized. Furthermore, since the protrusion 18 is also arranged at the boundary portion of the reflective display region R, the alignment regulating force by the protrusion 18 can be greatly exerted on the reflective display region R.

  The protrusion 18 is formed in an open ring shape having a cut 18A at the boundary between the reflective display region R and the transmissive display region T. The size of the protrusion 18 is the width d3 of the protrusion 18 (of the island portions 31a and 31b). The vertical dimension of the cut 18A extending in the arrangement direction is set to 10 μm, and the width d4 of the cut 18A (the horizontal dimension perpendicular to the arrangement direction of the islands 31a and 31b) is set to 12 μm. By adopting such a dimension and shape, the nucleus of the disclination can be more firmly fixed to the portion of the cut 18A of the protrusion 18 (see Table 2). The dimensional shape of the cut line 18A is not limited to this. If the dimension d3 in the vertical direction is 8 μm or more and 20 μm or less and the dimension d4 in the horizontal direction is 5 μm or more and 20 μm or less, the disclination core can be firmly fixed and good visibility can be obtained. .

  The TFT 30 is interposed between the island-like portion 31b on the lower side in the figure, the scanning line 3a, and the data line 6a. The TFT 30 includes a semiconductor layer 33, a gate electrode portion 32 provided on the lower layer side (substrate body 25 </ b> A side) of the semiconductor layer 33, a source electrode portion 34 provided on the upper layer side of the semiconductor layer 33, and a drain electrode portion 35. And is configured. A channel region of the TFT 30 is formed in a region facing the gate electrode portion 32 of the semiconductor layer 33, and a source region and a drain region are formed in the semiconductor layers on both sides thereof.

The gate electrode portion 32 is formed by branching a part of the scanning line 3a in the extending direction of the data line 6a, and is opposed to the semiconductor layer 33 via an insulating film (not shown) on the tip side. The source electrode portion 34 is formed by branching a part of the data line 6a in the extending direction of the scanning line 3a, and is electrically connected to the source region of the semiconductor layer 33 through a contact hole (not shown). Yes. One end side of the drain electrode 35 is electrically connected to the drain region through a contact hole (not shown), and the other end side of the drain electrode 35 is connected to the island portion 31b (directly or through the contact hole C). The pixel electrode 31) is electrically connected.
The TFT 30 is turned on only for a predetermined period by a gate signal input via the scanning line 3a, so that an image signal supplied via the data line 6a can be written to the liquid crystal at a predetermined timing. It is like that.

  On the other hand, when viewing the cross-sectional structure shown in FIG. 11, the liquid crystal display device 400 includes the element substrate 25 and the counter substrate 10 disposed to face the element substrate 25, and the initial alignment state is vertically aligned between the substrates 10 and 25. A liquid crystal layer 50 made of liquid crystal having negative dielectric anisotropy is sandwiched. A backlight (not shown) having a light source, a reflector, a light guide plate, and the like is provided as illumination means outside the liquid crystal cell corresponding to the outer surface side of the element substrate 25.

  The element substrate 25 has a substrate body 25A made of a translucent material such as quartz or glass as a base, and the scanning lines 3a are formed on the inner surface side (liquid crystal layer side) of the substrate body 25A. Then, a gate insulating film is formed so as to cover the scanning line 3a, a data line 6a and the like are formed on the gate insulating film, and the pixel electrode 31 is interposed via an interlayer insulating film 15 formed so as to cover the data line and the like. Is formed. The pixel electrode 31 connects the light-reflective island portion 31a provided in the reflective display region R, the light-transmissive island portion 31b provided in the transmissive display region T, and the electrode portions 31a and 31b. It is comprised by the connection part 31c for. The electrode portions 31b and 31b are made of a transparent conductive material such as ITO, and a connecting portion 31c is formed by providing a slit-like opening (electrode slit) 31B in the rectangular electrode portion 31b. The electrode portion 31b disposed in the transmissive display region T is provided with an opening 31A at the center. The opening 31A and the opening 31B function as alignment regulating means for controlling the alignment of the liquid crystal. That is, the tilt direction of the liquid crystal can be controlled by the action of the oblique electric field generated at the edges of the openings 31A and 31B. The size of the opening 31B is adjusted so that the dimension of the connecting part 31c is within the above-described dimension range, and the nucleus of the disclination can be fixed in the region where the connecting part 31c is formed. ing. A contact hole C (see FIG. 10) is formed in the interlayer insulating film 15 at a position facing the protrusion 18, and the TFT 30 and the island portion 31 b (pixel electrode 31) are electrically connected to the contact hole via C. Connected. Although not shown, a vertical alignment film such as polyimide is formed so as to cover the pixel electrode 31 and the interlayer insulating film 15, and the initial alignment of the liquid crystal molecules is aligned perpendicular to the substrate surface. A phase difference plate 36 and a polarizing plate 37 are sequentially stacked on the outer surface side of the substrate body 25A. The TFT 30 shown in FIG. 10 is provided between the interlayer insulating film 15 and the substrate body 25A.

  The counter substrate 10 has a substrate body 10A made of a translucent material such as quartz or glass as a base, and a color filter (color filter) is formed on the inner surface side of the substrate body 10A across the reflective display region R and the transmissive display region T. Layer) 22 is provided. The color filter 22 is composed of a plurality of types of color filters (colored layers) having different colors, and a light shielding layer BM (black matrix) made of black resin or the like between the color filters constituting the color filter layer 22 as necessary. ) Is arranged. An insulating film 81 is selectively formed on the inner surface side of the color filter 22 corresponding to the reflective display region R. As described above, the insulating film 81 partially formed in the dot region makes the thickness of the liquid crystal layer 50 different between the reflective display region R and the transmissive display region T. The insulating film 81 is formed using an organic material film such as an acrylic resin. The insulating film 81 is formed to have a thickness of, for example, about 2 μm ± 1 μm. The thickness of the liquid crystal layer 50 where the insulating film 81 does not exist is about 2 μm to 6 μm, and the thickness of the liquid crystal layer 50 in the reflective display region R is transmissive. This is about half the thickness of the liquid crystal layer 50 in the display region T. That is, the insulating film 81 functions as a liquid crystal layer thickness adjusting layer that varies the thickness of the liquid crystal layer 50 in the reflective display region R and the transmissive display region T according to its own film thickness, thereby realizing a multi-gap structure. It has become. The liquid crystal display device 200 of this example is configured so that a bright and high-contrast display can be obtained.

  Further, the counter electrode 9 is formed on the inner surface side of the substrate body 25 </ b> A so as to cover the surfaces of the color filter 22 and the insulating film 81. The counter electrode 31 is a transparent conductive film made of flat solid ITO or the like, and an annular projection 18 made of a dielectric material is disposed on the counter electrode 9 along the edge of the transmissive display region T. . As described above, the protrusion 18 constitutes an alignment regulating means for controlling the alignment of the transmissive display region T together with the electrode slits 31A and 31B on the element substrate side. Further, this alignment regulating force can be applied to the reflective display region R by the protrusions 18 arranged at the boundary with the reflective display region R. Further, the projection 18 is provided with a cut 18A (see FIG. 10) having the above-described dimensions at the boundary between the reflective display region R and the transmissive display region T, and the disclination is formed in the region where the cut 18A is formed. Can be fixed. Although not shown, a vertical alignment film is formed so as to cover the counter electrode 9 and the color filter 22, and the initial alignment of the liquid crystal molecules 51 is aligned perpendicular to the substrate surface. A phase difference plate 16 and a polarizing plate 17 are laminated on the outer surface side of the substrate body 10A.

  As described above, since the multi-gap structure is also adopted in this embodiment, a high-contrast display can be obtained in both the reflective display and the transmissive display. In the present embodiment, the dimensional shape of the connecting portion 31c is defined as described above, and the dimensional shape of the cut 18A of the protrusion 18 provided at the boundary between the reflective display region R and the transmissive display region T is defined as described above. Therefore, the core of the disclination is fixed to the formation region of the connecting portion 31c and the cut 18A, and does not move. For this reason, the rough display defect which arises when the said nucleus moves is improved, and a reflective display with sufficient visibility comes to be obtained. In this configuration, since structures such as protrusions are not arranged in the reflective display area, the display area is increased correspondingly and a bright reflective display can be obtained. Further, in the present embodiment, the protrusion 18 and the contact hole C are arranged so as to overlap in a planar manner, so that light leakage caused by disclination occurring in the contact hole portion can be blocked.

[Electronics]
FIG. 12 is a perspective view showing an example of an electronic apparatus according to the present invention. A cellular phone 1300 shown in this figure includes the liquid crystal display device of the present invention as a small-sized display portion 1301 and includes a plurality of operation buttons 1302, an earpiece 1303, and a mouthpiece 1304.
The display device of each of the above embodiments is not limited to the mobile phone, but is an electronic book, a personal computer, a digital still camera, a liquid crystal television, a viewfinder type or a monitor direct view type video tape recorder, a car navigation device, a pager, and an electronic notebook. , Calculators, word processors, workstations, video phones, POS terminals, devices equipped with touch panels, etc., and can be suitably used as image display means. In any electronic device, it is bright, has high contrast, and has a wide viewing angle. Transmissive / reflective display is possible.

The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but it goes without saying that the present invention is not limited to such examples. Various shapes, combinations, and the like of the constituent members shown in the above-described examples are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.
For example, the liquid crystal layer thickness adjusting layer 81 may be disposed on either the element substrate or the counter substrate, or may be disposed on both substrates. In the embodiment, the liquid crystal layer thickness adjusting layer is disposed in the reflective display area. However, the liquid crystal layer thickness adjusting layer may be disposed in both the transmissive display area and the reflective display area. In this case, for example, the liquid crystal layer thickness can be balanced by making the liquid crystal layer thickness adjusting layer in the reflective display region thicker than the liquid crystal layer thickness adjusting layer in the transmissive display region. The color filter 22 may be disposed on either the element substrate or the counter substrate as long as it is disposed on the observation side of the reflective film (reflective electrode). In each embodiment, the switching element may be either a TFT or TFD. In the first to third embodiments, the switching element may be a TFT element, or in the fourth embodiment, the switching element may be a TFD element. It is. In addition, the arrangement of constituent members such as electrode slits and protrusions can be freely changed. Furthermore, in the above-described embodiment, an example in which the present invention is applied to an active matrix liquid crystal display device has been described. However, the present invention can also be applied to a passive matrix liquid crystal display device that does not include a switching element.

The circuit block diagram of the liquid crystal display device which concerns on 1st Embodiment. The top view which shows the structure of the dot area | region of a liquid crystal display device similarly. FIG. 3 is a plan configuration diagram of one pixel region. FIG. 4 is a cross-sectional configuration diagram taken along line A-A ′ of FIG. 3. FIG. 6 is a plan configuration diagram of one pixel region of a liquid crystal display device according to a second embodiment. FIG. 6 is a cross-sectional configuration diagram taken along line B-B ′ of FIG. 5. FIG. 10 is a plan configuration diagram of one pixel region of a liquid crystal display device according to a third embodiment. FIG. 8 is a cross-sectional configuration diagram taken along line D-D ′ in FIG. 7. The circuit block diagram of the liquid crystal display device which concerns on 4th Embodiment. FIG. 3 is a plan configuration diagram of one pixel region. FIG. 11 is a cross-sectional configuration diagram taken along line E-E ′ of FIG. 10. FIG. 11 is a perspective configuration diagram illustrating an example of an electronic device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 9 ... Counter electrode, 10 ... Counter substrate, 15 ... Interlayer insulation film, 18 ... Protrusion (orientation control means), 18A ... Break, 25 ... Element substrate, 30 ... TFT (switching element), 31 ... Pixel electrode, 31A, 31B ... electrode slits (alignment regulating means), 31a, 31b ... island parts (subpixels), 31c ... connecting parts, 40 ... TFD elements (switching elements), 50 ... liquid crystal layers, 51 ... liquid crystal molecules, 81 ... insulating films ( (Liquid crystal layer thickness adjusting layer), 100, 200, 300, 400 ... liquid crystal display device, 1300 ... electronic device, C ... contact hole, D1, D2, D3 ... dot region, R ... reflection display region, T ... transmission display region

Claims (9)

A vertical alignment mode liquid crystal display device having a liquid crystal layer sandwiched between a pair of substrates and having a reflective display region and a transmissive display region in one dot region,
The liquid crystal layer is made of a liquid crystal having a negative dielectric anisotropy,
A liquid crystal layer thickness adjusting layer is provided between at least one of the pair of substrates and the liquid crystal layer so that the liquid crystal layer thickness of the reflective display region is smaller than the liquid crystal layer thickness of the transmissive display region. And
Each of the pair of substrates is provided with an electrode for driving the liquid crystal,
At least one of the electrodes of the pair of substrates has a plurality of island portions provided in the dot region and a connecting portion that electrically connects the adjacent island portions to each other. ,
The plurality of island-shaped portions are arranged in an integer number in each of the transmissive display area and the reflective display area,
The dimension of the connecting part is such that the dimension extending in the arrangement direction of the island-shaped parts is 8 μm or more and 20 μm or less, and the dimension perpendicular to the arrangement direction of the island-shaped parts is 5 μm or more and 20 μm or less. A liquid crystal display device.   A plurality of the connecting portions are provided between the adjacent island-shaped portions, and the plurality of connecting portions are symmetrical with respect to a line connecting the central portions of the adjacent island-shaped portions. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is arranged as described above.   The other substrate facing the substrate provided with the island-shaped portion has an alignment regulating means for regulating the alignment state of the liquid crystal when an electric field is applied at a position facing the island-shaped portion in the transmissive display region. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is provided.   The said orientation control means is the protrusion provided with the opening part provided in the electrode of said other board | substrate, or the dielectric material provided on the electrode of this other board | substrate. Liquid crystal display device. The substrate provided with the island-shaped portion is provided with a switching element electrically connected to the island-shaped portion through a contact hole,
5. The liquid crystal display device according to claim 3, wherein the contact hole and the alignment regulating means are arranged so as to overlap in a plane.   The liquid crystal display device according to claim 1, wherein the island-shaped portion has a substantially circular shape or a substantially regular polygonal shape in a plan view. A vertical alignment mode liquid crystal display device having a liquid crystal layer sandwiched between a pair of substrates and having a reflective display region and a transmissive display region in one dot region,
The liquid crystal layer is made of a liquid crystal having a negative dielectric anisotropy,
Between the liquid crystal layer and at least one of the pair of substrates, there is a liquid crystal layer thickness adjusting layer for making the liquid crystal layer thickness of the reflective display region smaller than the liquid crystal layer thickness of the transmissive display region. Provided,
On at least one of the pair of substrates, a protrusion made of a dielectric material is provided along an edge of the transmissive display region,
The protrusion is formed in an open ring shape having a cut at a boundary portion between the reflective display area and the transmissive display area,
The liquid crystal display device is characterized in that the projection has a width of 8 μm or more and 20 μm or less and a width of the cut of 5 μm or more and 20 μm or less. Each of the pair of substrates is provided with an electrode for driving the liquid crystal,
The other substrate facing the substrate provided with the protrusion is provided with a switching element electrically connected to an electrode provided in the transmissive display region of the other substrate through a contact hole. ,
The liquid crystal display device according to claim 7, wherein the contact hole is disposed so as to overlap the protrusion in a planar manner.   An electronic apparatus comprising the liquid crystal display device according to claim 1.

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