JP2005258183A - Liquid crystal display device and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transflective type liquid crystal display device, the liquid crystal display device capable of obtaining bright high-contrast display with a wide viewing angle. <P>SOLUTION: This liquid crystal display device employs a homeotropic alignment mode whose initial alignment is homeotropic alignment and which uses a liquid crystal layer 509, a transmission display area T is halved by a reflection display area R and arranged in a one-dot area, and an insulating film 21 for making the liquid crystal layer 50 thinner in a reflection display area R than in the transmission display area T is provided in the area of a dot center part which corresponds to the transmission display area T. In the transmission display area T and reflection display area R, sub-pixels are arranged in a corresponding state and also electrically connected. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a liquid crystal display device and an electronic apparatus, and more particularly to a technique capable of obtaining a display with a high contrast and a wide viewing angle in a transflective liquid crystal display device that performs display in both a reflection mode and a transmission mode. .

  Reflective liquid crystal display devices have low power consumption because they do not have a light source such as a backlight, and are conventionally widely used in various portable electronic devices. However, since the reflective liquid crystal display device performs display using external light such as sunlight or illumination light, it is difficult to visually recognize the display in a dark place. Therefore, a liquid crystal display device has been proposed in which external light is used in a bright place in the same manner as a normal reflective liquid crystal display device, and in a dark place, the display can be visually recognized by an internal light source such as a backlight. In other words, this liquid crystal display device employs a display method that combines both a reflective type and a transmissive type. By switching between the reflective mode and the transmissive mode depending on the ambient brightness, power consumption can be reduced. Even when the surroundings are dark, the display can be clearly displayed. Hereinafter, in this specification, this type of liquid crystal display device is referred to as a “transflective liquid crystal display device”.

  Such a transflective liquid crystal display device includes a configuration in which a liquid crystal layer is sandwiched between an upper substrate and a lower substrate, and a reflection in which a light transmission window is formed on a metal film such as aluminum. A liquid crystal display device has been proposed in which a film is provided on the inner surface of the lower substrate and this reflective film functions as a semi-transmissive reflective film. 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.

  By the way, the alignment mode of the liquid crystal includes a twisted nematic (hereinafter abbreviated as TN) mode in which liquid crystal molecules are twisted in a direction substantially parallel to the substrate surface and perpendicular to the substrate in the absence of voltage. And a vertical alignment mode in which liquid crystal molecules are aligned vertically. Conventionally, the TN mode has been the mainstream from the viewpoint of reliability and the like, but the vertical alignment mode liquid crystal device has attracted attention because the vertical alignment mode has some excellent characteristics.

  For example, in the vertical alignment mode, the state in which liquid crystal molecules are aligned perpendicular to the substrate surface (no optical retardation viewed from the normal direction) is used as black display, so the quality of black display is good and high. Contrast is obtained. Further, in the vertical alignment type LCD having excellent front contrast, the viewing angle range in which a constant contrast can be obtained is wider than that of the TN liquid crystal in the horizontal alignment mode. Furthermore, if an alignment division (multi-domain) technique for dividing the alignment direction of the liquid crystal in the pixel is employed, a very wide viewing angle can be obtained.

  In the transflective liquid crystal display device having the above-described configuration, for example, when the thickness of the liquid crystal layer is d, the refractive index anisotropy of the liquid crystal is Δn, and the retardation of the liquid crystal expressed as an integrated value thereof is Δn · d, the reflective display The retardation of the liquid crystal in the region is represented by 2 × Δn · d because the incident light reaches the observer after passing through the liquid crystal layer twice. On the other hand, the retardation of the liquid crystal in the transmissive display region is 1 × Δn · d because light from the backlight passes through the liquid crystal layer only once.

  As described above, when the alignment of the liquid crystal molecules in the liquid crystal layer is controlled while the reflection display area and the transmissive display area have different retardation values, an electric field is applied to the liquid crystal with the same driving voltage in each display mode. The orientation is controlled by application. In this case, high-contrast display cannot be obtained by aligning liquid crystals having different display forms in the liquid crystal, in other words, liquid crystals having different retardations in the transmissive display area and the reflective display area with the same driving voltage. There was a problem. In order to solve this problem, a liquid crystal display device having a structure in which the thickness of the liquid crystal layer is changed in the transmissive display region and the reflective display region has been proposed (for example, see Patent Document 1).

Japanese Patent Laid-Open No. 11-242226

  As described above, the use of the vertical alignment mode is also one method for achieving high contrast, and there is also a demand for configuring a liquid crystal display device by combining the transflective liquid crystal display device with the vertical alignment mode. However, it solves the problem of contrast reduction due to retardation difference in both the reflection and transmission display modes, the problem of resolution, the problem of alignment control in the vertical alignment mode (decrease in transmittance, spots, unevenness), and the problem of alignment division. At present, there are problems that have not been realized.

  The present invention has been made in order to solve the above-described problems, and is a transflective liquid crystal display device that is bright and has high contrast, and can obtain a wide viewing angle display. The purpose is to provide.

  In order to achieve the above object, a liquid crystal display device of the present invention comprises a liquid crystal layer having negative dielectric anisotropy sandwiched between a pair of substrates, and the opposing surface side of one of the pair of substrates. A plurality of dot regions corresponding to regions where the electrode formed on the substrate and the pixel electrode formed on the opposite surface side of the other substrate overlap each other, and a transmissive display region for performing transmissive display and a reflective display in one dot region A liquid crystal display device in which the thickness of the liquid crystal layer in the transmissive display region is set to be thicker than the layer thickness of the liquid crystal layer in the reflective display region. The pixel electrode in one dot region is configured to have subpixels arranged in at least three or more regions in the longitudinal direction of the pixel electrode, and each subpixel has the transmissive display. Territory And the sub-pixel corresponding to the transmissive display region, the sub-pixel corresponding to the reflective display region, and the sub-pixel corresponding to the transmissive display region, respectively. In this order, one dot region is arranged in the longitudinal direction of the pixel electrode.

  The liquid crystal display device of the present invention is a combination of a transflective liquid crystal display device and a vertical alignment mode liquid crystal. In recent years, in a transflective liquid crystal display device, for example, an insulating film having a predetermined thickness in a reflective display region on a lower substrate is used to solve the above-described problem of a decrease in contrast due to a retardation difference in both reflective and transmissive display modes. Has been proposed in which the thickness of the liquid crystal layer is changed between the reflective display region and the transmissive display region. The present applicant has already filed many applications for this type of liquid crystal display device. According to this configuration, since the thickness of the liquid crystal layer in the reflective display region can be made smaller than the thickness of the liquid crystal layer in the transmissive display region due to the presence of the insulating film, the retardation in the reflective display region and the retardation in the transmissive display region are sufficient. , Or substantially equal to each other, thereby improving the contrast.

  Therefore, the present inventors have found that the alignment direction when an electric field is applied to a vertical alignment mode liquid crystal can be controlled by combining the liquid crystal display device having the above insulating film with a vertical alignment mode liquid crystal layer. In other words, when the vertical alignment mode is adopted, a negative type liquid crystal is generally used. However, in the initial alignment state, liquid crystal molecules standing perpendicular to the substrate surface are defeated by applying an electric field. If the device is not devised (if pretilt is not applied), the direction in which the liquid crystal molecules fall cannot be controlled, and the alignment will be disturbed (disclination), resulting in display defects such as light loss, and the display quality will be degraded. . Therefore, in adopting the vertical alignment mode, the control of the alignment direction of the liquid crystal molecules when an electric field is applied is an important factor. Therefore, in a liquid crystal display device having an insulating film in which the liquid crystal layers of the transmissive display region and the reflective display region have different thicknesses, the insulating film protrudes toward the liquid crystal layer. After exhibiting vertical alignment in the initial state, it has a pretilt corresponding to the surface of the stepped portion or the inclined portion. This action makes it possible to control the alignment direction of the liquid crystal molecules when an electric field is applied, so that a display with high contrast can be realized without display defects such as light leakage.

  That is, according to the configuration of the present invention, by providing an insulating film in a transflective liquid crystal display device in a vertical alignment mode, both reflection and transmission have been a fundamental problem in the conventional transflective liquid crystal display device. It is possible to solve the problem of contrast reduction due to the retardation difference in the display mode, and at the same time, it is possible to suppress display defects caused by the fact that the alignment direction of the liquid crystal molecules in the vertical alignment mode cannot be controlled. As a result, it is possible to take advantage of both the advantages of the vertical alignment mode and the transflective type, and to realize a liquid crystal display device with excellent display quality.

  In addition, the first subpixel corresponding to the transmissive display area, the second subpixel corresponding to the reflective display area, and the third subpixel corresponding to the transmissive display area are arranged in this order in the pixel electrode. Therefore, the resolution is improved by dividing the reflection display area into two in the longitudinal direction of the pixel electrode.

  Further, the stepped portion or the inclined portion by the insulating film that makes the liquid crystal layer thicknesses of the reflective display region and the transmissive display region different from each other is between the first subpixel and the second subpixel, and between the second subpixel and the second subpixel. The pretilt of the liquid crystal molecules provided at the stepped portion or the inclined portion is defined in the longitudinal direction of the pixel electrode, and the alignment control has not been possible so far. Therefore, the stepped portion or the inclined portion that has not contributed to the display can be effectively used as the starting point of the alignment division (or as an operation to supplement the alignment control). That is, the two pre-tilts generated in the two stepped portions or inclined portions existing in the longitudinal direction of the pixel electrode are arranged in alignment with the alignment directions of the liquid crystal molecules in the two transmissive display regions. The stepped portion or the inclined portion at the location can be used as a region having an alignment direction by pretilt, and a wide viewing angle can be achieved by realizing an alignment division structure.

  The liquid crystal display device of the present invention includes a switching element that drives the pixel electrode for each pixel electrode, and each subpixel of the pixel electrode in one dot region is electrically connected. The electrical connection between the pixel electrode and the switching element is achieved in the sub-pixel formed of a reflective film corresponding to the reflective display region.

  According to this configuration, the same drive voltage can be easily applied simultaneously to the electrode (subpixel) in the reflective display area and the electrode (subpixel) in the transmissive display area.

  In the liquid crystal display device of the present invention, the electrical connection between the switching element and the sub-pixel formed of a reflective film corresponding to the reflective display area is wired from the switching element toward the reflective display area. The wiring portion is connected to the reflective display region through a contact hole.

  In the liquid crystal display device of the present invention, a liquid crystal layer is sandwiched between a pair of substrates, and the electrodes formed on the opposing surface side of one of the pair of substrates and the opposing surface side of the other substrate are formed. A plurality of dot areas corresponding to areas overlapping with the pixel electrodes formed, and a transmissive display area for performing transmissive display and a reflective display area for performing reflective display are individually provided in the dot area, and A liquid crystal display device in which a layer thickness of the liquid crystal layer in the display region is set to be thicker than a layer thickness of the liquid crystal layer in the reflective display region, and the liquid crystal layer on the surface of the one substrate on the liquid crystal layer side A stepped portion or an inclined portion exists between the reflective display region and the transmissive display region having different layer thicknesses, and each pixel electrode is provided with a switching element for driving the pixel electrode, and the pixel electrode and the switching Electrical connection to the child, characterized in that it is connected through a contact hole provided in the stepped portion or inclined portion.

  According to the above configuration, the electrical connection between the switching element and the pixel electrode is a region that does not contribute to display (a region that cannot be used as a display region by controlling the orientation of liquid crystal molecules), that is, a reflective display region. Since it is performed through the contact hole at the stepped portion or the inclined portion generated at the boundary of the transmissive display region, the opening efficiency is not reduced. In addition, since contact holes are originally formed in regions that do not contribute to display, alignment control such as vertical alignment is not affected.

  In the liquid crystal display device according to the present invention, the electrode formed on the opposite surface side of the one substrate is formed with a slit that opens the electrode corresponding to each subpixel. To do.

  In the liquid crystal display device of the present invention, the electrode formed on the opposite surface side of the one substrate is provided with a protrusion made of a dielectric on the electrode corresponding to each subpixel. It is characterized by.

  The liquid crystal display device of the present invention is characterized in that the protrusion or the slit is planarly arranged at a substantially central portion of the subpixel.

  In the liquid crystal display device of the present invention, a stepped portion or an inclined portion is provided on the surface of the one substrate on the liquid crystal layer side between the reflective display region and the transmissive display region having a different layer thickness of the liquid crystal layer. The electrical connection of the sub-pixels of the pixel electrode in one dot region is connected by a wiring formed on the stepped portion or the inclined portion.

In the liquid crystal display device of the present invention, the shape of the subpixel in the one dot region is a regular polygon or a circle.
According to this configuration, the liquid crystal molecules are evenly divided in each direction in each subpixel. That is, since the alignment of the liquid crystal molecules is controlled radially, the viewing angle at which the contrast is good can be expanded isotropically.
Furthermore, by providing circularly polarized light incident means for making circularly polarized light incident on the one substrate and the other substrate, it is possible to perform good display for both reflective display and transmissive display.

According to another aspect of the invention, an electronic apparatus includes the above-described liquid crystal display device.
According to this configuration, it is possible to provide an electronic device including a liquid crystal display unit that is bright, has high contrast, and has a wide viewing angle regardless of the use environment.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
The liquid crystal display device of this embodiment is an example of an active matrix liquid crystal display device using a thin film transistor (hereinafter abbreviated as TFT) as a switching element.

  FIG. 1 is an equivalent circuit diagram of a plurality of dots arranged in a matrix constituting the image display area of the liquid crystal display device of this embodiment, and FIG. 2 shows the structure of one dot area formed on the TFT array substrate. FIG. 3 is a plan view showing a cross-sectional structure of the same dot region, and is a cross-sectional view taken along the line AA ′ of FIG. In each of these drawings, the scale of each layer and each member is different in order to make each layer and each member recognizable on the drawing.

  In the liquid crystal display device according to the present embodiment, as shown in FIG. 1, a pixel electrode 9 and switching for driving and controlling the pixel electrode 9 are provided for a plurality of dots arranged in a matrix that forms an image display area. The TFT 30 as an element is formed, and the data line 6a to which an image signal is supplied is electrically connected to the source 30S 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 30G 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. . The pixel electrode 9 is electrically connected to the drain 30D of the TFT 30, and the image signals S1, S2,..., Sn supplied from the data line 6a are obtained by turning on the TFT 30 as a switching element for a certain period. Write at a predetermined timing.

  A predetermined level of image signals S1, S2,..., Sn written to the liquid crystal via the pixel electrode 9 is held for a certain period with the common electrode described later. 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 9 and the common electrode. Reference numeral 3b denotes a capacity line.

Next, the planar structure of the TFT array substrate constituting the liquid crystal device of the present embodiment will be described with reference to FIG.
As shown in FIG. 2, on the TFT array substrate, a plurality of TFTs 30 and pixel electrodes 9 are formed corresponding to the intersections between the data lines 6a and the scanning lines 3a, and the pixel electrodes 9 are provided in a matrix. Here, the pixel electrode 9 is composed of a plurality of island-like subpixels (5a, 5b, 5c), and each subpixel is electrically connected. That is, the sub-pixel 5a and the sub-pixel 5b, and the sub-pixel 5b and the sub-pixel 5c are electrically connected through the connection portion 8, respectively, and form a longitudinal direction in which they are connected. Here, the sub-pixel 5a and the sub-pixel 5c are formed of a transparent electrode and are a transmissive display region T. The subpixel 5b located between the subpixel 5a and the subpixel 5c is a reflective electrode formed of a reflective metal (for example, aluminum, silver, or a metal film containing these as a main component). . In the lower layer of the reflective subpixel 5b, the capacitor line 3b is provided so as to extend substantially linearly in a direction intersecting with the longitudinal direction of the pixel electrode. In the present embodiment, the inside of each pixel electrode 9 and the region where the data line 6a, the scanning line 3a, the capacitance line 3b, etc., which are arranged so as to surround each pixel electrode 9 are formed is one dot region, The display is made possible for each dot area arranged in a matrix.

  The data line 6a is electrically connected to a source region 30S, which will be described later, of the semiconductor layer that constitutes the TFT 30, for example, a polysilicon film, and the pixel electrode 9 is a drain region 30D, which is described later, of the semiconductor layer. Is electrically connected. In the semiconductor layer, the scanning line 3a is disposed so as to face the channel region, and the scanning line 3a functions as the gate electrode 30G in a portion facing the channel region.

  Further, the pixel electrode 9 and the TFT 30 are electrically connected to each other in the sub pixel 5b arranged in the reflective display region R through the wiring portion 34 derived from the drain region 30D and the contact hole 7. As shown in the drawing, the wiring part 34 is wired by sewing the substantial center of the subpixel 5c arranged in the transmissive display region T in plan view, and is electrically connected through the contact hole 7 at the substantial central part of the subpixel 5b of the reflective electrode. It is connected to the.

As shown in FIG. 2, a circular reflective electrode sub-pixel 5b is formed at the center of one dot region, and the region in which the sub-pixel 5b is formed becomes the reflective display region R, and the connecting portion 8 A region where the sub-pixels 5a and 5c made of transparent electrodes electrically connected to both sides of the sub-pixel 5b of the reflective electrode are formed as a transmissive display region T. In addition, the insulating film 21 is formed so as to be wider than the formation region of the sub-pixel 5b of the reflective electrode in a band shape in one dot region in a direction along the capacitance line 3b when viewed in plan.
Further, since the portion where the connecting portion 8 for connecting each subpixel is present has a shape (notched portion K) that is notched to divide each subpixel, this notched portion K is a vertical that will be described later. It has a function as a slit for controlling the alignment of the liquid crystal molecules 50 ′ in the alignment (VA) mode.

  Next, a cross-sectional structure of the liquid crystal display device of the present embodiment will be described based on FIG. FIG. 3 is a cross-sectional view taken along the line AA ′ in FIG. 2 (one dot region or the longitudinal direction of the pixel electrode). The present invention is characterized by the configuration of the insulating film 21 in the center of the dot region D. Furthermore, the connection structure for electrically connecting the TFT 30 and the pixel electrode 9 is characterized.

  As shown in FIG. 3, a liquid crystal layer 50 made of liquid crystal having an initial alignment state of vertical alignment is sandwiched between the TFT array substrate 10 and a counter substrate 25 disposed so as to be opposed thereto. In the TFT array substrate 10, scanning lines (gate lines) 3a and capacitance lines 3b are formed on the surface of a substrate body made of a translucent material such as quartz or glass. Further, a wiring portion 34 formed by wiring from the TFT 30 (drain 30D) is routed through the insulating film to the reflective display region R on the capacitor line 3b. Further, an insulating film 21 that substantially varies the thickness (dt, dr) of the liquid crystal layer 50 in each of the reflective display region R and the transmissive display region T is formed on the wiring portion 34. The reflective display region R is arranged at substantially the center of D, and the layer thickness dr of the liquid crystal layer 30 in the reflective display region R is made smaller than the layer thickness dt of the liquid crystal layer 50 in the transmissive display region T corresponding to this region ( An insulating film 21 is formed. The insulating film 21 may be formed integrally with the half-tone mask (gray mask) after the formation of the capacitor line 34 or by gradation exposure, or a portion protruding substantially toward the liquid crystal layer 50 (substantially). Only the portions where the thicknesses of the liquid crystal layers are different may be formed separately in separate steps. A portion protruding toward the liquid crystal layer 50 (a portion where the thickness of the liquid crystal layer is substantially different) corresponds to the reflective display region R, and the transmissive display region T is divided into two in the dot region D. The insulating film 21 is made of an organic film such as acrylic resin having a film thickness of about 2 to 3 μm, for example, and is inclined so that its layer thickness continuously changes in the vicinity of the boundary between the reflective display region R and the transmissive display region T. An inclined region (stepped portion or inclined portion) S provided with Since the thickness of the liquid crystal layer 50 in the portion where the insulating film 21 does not exist is about 4 to 6 μm, the thickness of the liquid crystal layer 50 in the reflective display region R is about half of the thickness of the liquid crystal layer 50 in the transmissive display region T. That is, the insulating film 21 functions as a liquid crystal layer thickness control layer that varies the thickness of the liquid crystal layer 50 between the reflective display region R and the transmissive display region T depending on its own film thickness. Further, the angle θ formed by the plane and the inclined surface of the insulating film 21 is about 10 ° to 50 °.

Therefore, the surface on the liquid crystal layer side of the insulating film 21 corresponding to the reflective display region R is provided with irregularities and is subjected to a rough surface treatment. Therefore, when the sub-pixel 5b functioning as a reflective electrode is formed on the aluminum (reflecting metal material) described later, the roughened unevenness is reflected on the surface, which is bright and good. Reflective characteristics can be obtained. However, at the interface with the alignment film on the liquid crystal layer side, the roughened unevenness is very fine so as not to affect the alignment control.
Here, the portion protruding from the insulating film 21 toward the liquid crystal layer 50 (the portion where the thickness of the liquid crystal layer is substantially different) is led out from the TFT 30 (drain 30D) described above, and wiring is formed. A contact hole 7 having a depth reaching the wiring portion 34 is formed. Therefore, the contact hole 7 and the wiring part 34 are electrically connected to the pixel electrode 9 and the TFT 30 by forming a subpixel 5b made of aluminum (a reflective metal material) described later. That is, the electrical connection between the TFT 30 and the pixel electrode 9 is such that the sub-pixel 5b of the reflective display region R that bisects the transmissive display region T by the wiring portion 34 and the contact hole 7 derived from the TFT 30 (drain 30D). It is the structure made in.

  Then, on the surface of the TFT array substrate 10 including the surface of the insulating film 21, island-shaped circular subpixels 5 a and 5 c are formed at positions corresponding to the transmissive display region T with indium tin oxide (Indium Tin Oxide, (Hereinafter abbreviated as ITO) or the like, and at the position corresponding to the reflective display region R, an island-like circular subpixel 5b is formed as a reflective electrode with aluminum (a metallic material having reflectivity). ing. At this time, the contact hole 7 described above is arranged substantially at the center of the sub-pixel 5b. Each sub-pixel is electrically connected, and the connection between the sub-pixel 5c arranged in one transmissive display region T and the sub-pixel 5b arranged in the reflective display region R, and the sub-pixel arranged in the reflective display region R. The connection between the pixel 5b and the sub-pixel 5a disposed in the other transmissive display region T is illustrated by a connection portion 8 formed in a linear shape. And all this connection part 8 is located in the inclination area | region (step part or inclination part) S provided with the above-mentioned inclined surface. Further, the connection portion 8 may be formed integrally with these subpixels by the same ITO material as that of the subpixel 5a and the subpixel 5c, and aluminum (having reflectivity) integrally with the subpixel 5b. (Metal material). In the latter case, light leakage from the inclined region (stepped portion or inclined portion) S that does not contribute to display can be prevented. In addition, in the electrical connection between the connection portion 8 for connecting the subpixels and / or the subpixel formed of ITO and the subpixel formed of aluminum (a reflective metal material), ITO and aluminum are used. An electrical connection can be easily achieved by superimposing one of the (reflective metal material) on the other. Thus, in one dot region D, the pixel electrode 9 composed of these subpixels 5a, 5b, and 5c is formed, and the vertical alignment film 12 is further formed thereon.

  On the other hand, the counter substrate 25 is provided with a color filter CFR for reflection display in a position overlapping in a plane in the reflection display region R, and a color filter CFT in transmission display in a position overlapping in a plane in the transmission display region T. Is provided. In general, in a transflective liquid crystal display device, light is transmitted twice through a color filter in reflective display, but is transmitted only once in transmissive display. Therefore, the saturation of display colors in reflective display and transmissive display. There is a problem that is different. In view of this, the present applicant has proposed a technique for changing the color purity of the dye layer of the color filter between the reflective display region R and the transmissive display region T and improving the balance of display colors between the reflective display and the transmissive display. In addition, the color purity of the color filter formed in the reflective display region R is formed by forming a non-colored region while keeping the color purity of the color layer of the color filter in the reflective display region R and the transmissive display region T the same. It is also possible to adopt a method of realizing a visually bright color display although it decreases and becomes light. Each of the dye layers of the reflective display color filter CFT and the transmissive display color filter CFT employs this technique.

  A transparent common electrode 11 made of ITO or the like is formed on the pigment layer of the color filter CFR for reflection display and the color filter CFT for transmission display. Here, the common electrode 11 is provided with alignment control means for controlling the alignment of the liquid crystal molecules 50 ′ of the liquid crystal layer 50. The orientation control means is provided at a planar position corresponding to the substantially center (center) portion of each subpixel formed on the TFT array substrate 10 side in the common electrode 11. This is due to the protrusion 13 made of a dielectric or the slit 14 having the common electrode 11 opened. In FIG. 3, the protrusions 13 made of a dielectric are shown as the orientation control means. Here, as shown in FIG. 4, the shape of the protrusion 13 or the slit 14 used as the orientation control means may be circular in the center with respect to the subpixel in plan view, and may be polygonal or cross-shaped. However, it may be X shape. In particular, the liquid crystal molecules are continuously aligned if they are circular protrusions or slits in plan view, that is, the occurrence of disclination in which the alignment direction becomes discontinuous is suppressed, and it does not exist on the subpixel, so the transmittance A liquid crystal display device having a high viewing angle and a wide viewing angle can be provided.

  Although not shown, a circularly polarizing plate is provided on the outer surface side of the TFT array substrate 10, and a circularly polarizing plate is also provided on the outer surface side of the counter substrate 25. Further, although not shown, a backlight (illuminating device) is actually arranged on the back side of the TFT array substrate 10, and reflection display using external light (reflection arranged in the reflection display region R) is performed. It is a liquid crystal display device that realizes both display (display by subpixels made of electrodes) and transmissive display using light emitted from the backlight (display by subpixels made of ITO arranged in the transmissive display region T). Yes.

  Further, as shown in FIGS. 6 and 7, the shape of each sub-pixel may be a square or an octagon. In this case, since the above-mentioned alignment control means is arranged in the center of each subpixel in a plane, in the case of a subpixel polygonal shape, the liquid crystal molecules tilt from the center in the subpixel toward each side. Will do.

  Furthermore, as another embodiment, as shown in FIG. 8, in the configuration of the pixel electrode 9, a plurality of subpixels in the reflective display region R and a plurality of subpixels in the transmissive display region T are provided. 5) in a grid pattern. Accordingly, the sub-pixels arranged in the vertical and horizontal directions as the pixel electrode 9 are electrically connected to the adjacent sub-pixels in the vertical and horizontal directions by the connecting portions 8, and there are a plurality of electrical connection paths. In addition, when the pixel electrode 9 is configured by a plurality of subpixels in this way, the electrical connection between the wiring portion 34 drawn out from the TFT 30 and the pixel electrode 9 in the reflective display region R is performed by a plurality of contact holes 7. It is preferable to carry out by. According to such a configuration, display can be performed with normal subpixels without sacrificing the entire dot region D exhibiting display defects in each of the reflective display region R and the transmissive display region T. Since a plurality of domains can be formed in each of the reflective display region R and the transmissive display region T in a lattice shape, the orientation of the liquid crystal layer is stabilized throughout the dot region D, and the viewing angle dependency of display quality is improved. Can be improved.

Here, the alignment control by the protrusions 13 and the slits 14 of the liquid crystal layer having negative dielectric anisotropy will be briefly described with reference to FIGS.
FIG. 5A shows the action of alignment control by the slit 14, and schematically shows the state of the liquid crystal molecules 50 ′ in a state where the electric field action is applied (that is, a state where a voltage is applied to the electrode). It is a thing. The liquid crystal molecules 50 ′ of the liquid crystal layer having negative dielectric anisotropy exhibit an alignment in which the major axes of the liquid crystal molecules 50 ′ are aligned in a direction substantially perpendicular to the substrate in the initial alignment state when no voltage is applied. When an electric field action acts between the pixel electrode 9 and the common electrode 11 with the layers sandwiched, that is, when a potential difference is generated between the pixel electrode 9 and the common electrode 11, an electric field acts on the liquid crystal molecules 50 '. The major axis tends to fall in a direction that intersects the direction. The direction in which the electric field acts when the slit 14 is formed is that the lateral electric field component across the slit 14 acts, so that the direction from the center of the slit 14 toward the outside depends on the electric field strength due to the applied voltage. As a result, the liquid crystal molecules 50 ′ are gradually tilted.
Next, FIG. 5B shows the effect of orientation control by the protrusions 13 made of a dielectric, and the liquid crystal molecules 50 ′ in a state where an electric field action is applied (that is, a state where a voltage is applied to the electrode). Is schematically shown. The liquid crystal molecules 50 ′ of the liquid crystal layer having negative dielectric anisotropy exhibit an alignment in which the major axes of the liquid crystal molecules 50 ′ are aligned in a direction substantially perpendicular to the substrate in the initial alignment state when no voltage is applied. When an electric field action acts between the pixel electrode 9 and the common electrode 11 with the layers sandwiched, that is, when a potential difference is generated between the pixel electrode 9 and the common electrode 11, an electric field acts on the liquid crystal molecules 50 '. The major axis tends to fall in a direction that intersects the direction. Here, since the surface of the protrusion 14 on the liquid crystal layer side is inclined, a pretilt is given to the liquid crystal molecules 50 '. That is, in the case of the projection 14 provided in a hemispherical shape, the surface is inclined outward from the central portion of the projection 14, so that the liquid crystal molecules 50 ′ are radially (axially symmetric) outward from the central portion of the projection 13. The liquid crystal molecules 50 ′ are gradually tilted. That is, the tilted surface of the protrusion 13 defines the tilting direction of the liquid crystal molecules 50 ′ when a voltage is applied.

  According to the liquid crystal display device of the present embodiment, by providing the insulating film 21 in the reflective display region R, the thickness of the liquid crystal layer 50 in the reflective display region R is approximately half the thickness of the liquid crystal layer 50 in the transmissive display region T. Since it can be made smaller, the retardation in the reflective display region R and the retardation in the transmissive display region T can be made substantially equal, thereby improving the contrast. Further, since the insulating film 21 protrudes toward the liquid crystal layer 50 and the insulating film 21 forms an inclined region (stepped portion or inclined portion) S having an inclined surface, the liquid crystal molecules 50 ′ are vertically aligned in the initial state. And a pretilt corresponding to the shape of the inclination of the inclined region. By this action, the orientation direction of the liquid crystal molecules 50 ′ when an electric field is applied can be controlled, so that a display with high contrast can be realized without display defects such as light leakage.

  That is, according to the configuration of the present embodiment, by providing the insulating film 21 in the transflective liquid crystal display device in the vertical alignment mode, it is possible to solve the problem of contrast reduction due to the retardation difference in both the reflective and transmissive display modes. At the same time, it is possible to suppress display defects due to the fact that the alignment direction of the liquid crystal molecules in the vertical alignment mode cannot be controlled. As a result, it is possible to take advantage of both the advantages of the vertical alignment mode and the transflective type, and to realize a liquid crystal display device with excellent display quality.

  In the present embodiment, the reflective display region R is provided at the center of one dot region D, and the insulating film 21 is provided at a location corresponding to the reflective display region R at the center of the dot region. Since the display area T can be distributed in two places, the apparent resolution can be improved. In addition, since the sub-pixels are arranged in each of the transmissive display region T and the reflective display region R, the alignment direction of the liquid crystal molecules is radial (starting from the alignment control means arranged in the center of each sub-pixel in a plane. Axis symmetry). As a result, an alignment division structure can be realized by forming three divided domains (one in the reflective display region R and two in the transmissive display region T) in one dot region. A wide viewing angle can be achieved.

  Further, the insulating film 21 has an inclined region S in the vicinity of the boundary between the reflective display region R and the transmissive display region T, and the alignment state of the liquid crystal molecules 50 ′ is also continuous according to the position of the inclined surface of the insulating film 21. And continuously changing in the direction (longitudinal direction) along the tilt direction of the liquid crystal molecules 50 ′ in the transmissive display region T in the vicinity of the boundary. It can be avoided.

[Second Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
The liquid crystal display device of this embodiment is an example of an active matrix liquid crystal display device using a thin film transistor (hereinafter abbreviated as TFT) as a switching element.

  9 is a plan view showing the structure of one dot region formed on the TFT array substrate, and FIG. 10 is a cross-sectional view showing the cross-sectional structure of the same dot region, which is a cross section taken along the line AA ′ of FIG. FIG. In each of these drawings, the scale of each layer and each member is different in order to make each layer and each member recognizable on the drawing.

Based on FIG. 9, the planar structure of the TFT array substrate constituting the liquid crystal device of the present embodiment will be described.
As shown in FIG. 9, a plurality of TFTs 30 and pixel electrodes 9 are formed on the TFT array substrate corresponding to the intersections of the data lines 6a and the scanning lines 3a, and the pixel electrodes 9 are provided in a matrix. Here, the pixel electrode 9 is composed of a plurality of island-like subpixels (5a, 5b, 5c), and each subpixel is electrically connected. That is, the sub-pixel 5a and the sub-pixel 5b, and the sub-pixel 5b and the sub-pixel 5c are electrically connected through the connection portion 8, respectively, and form a longitudinal direction in which they are connected. Here, the sub-pixel 5a and the sub-pixel 5c are formed of a transparent electrode and are a transmissive display region T. The subpixel 5b located between the subpixel 5a and the subpixel 5c is a reflective electrode formed of a reflective metal (for example, aluminum, silver, or a metal film containing these as a main component). . In the lower layer of the reflective subpixel 5b, the capacitor line 3b is provided so as to extend substantially linearly in a direction intersecting with the longitudinal direction of the pixel electrode. In the present embodiment, the inside of each pixel electrode 9 and the region where the data line 6a, the scanning line 3a, the capacitance line 3b, etc., which are arranged so as to surround each pixel electrode 9 are formed is one dot region, The display is made possible for each dot area arranged in a matrix.

  The data line 6a is electrically connected to a source region 30S, which will be described later, of the semiconductor layer that constitutes the TFT 30, for example, a polysilicon film, and the pixel electrode 9 is a drain region 30D, which is described later, of the semiconductor layer. Is electrically connected. In the semiconductor layer, the scanning line 3a is disposed so as to face the channel region, and the scanning line 3a functions as the gate electrode 30G in a portion facing the channel region.

  Further, the electrical connection between the pixel electrode 9 and the TFT 30 is arranged in an inclined region (stepped portion or inclined portion) S having an inclined surface through the wiring portion 34 derived from the drain region 30D and the contact hole 7. The connection is made at the connection portion 8 of the subpixel. As shown in the figure, the wiring section 34 is arranged in the reflective display area R and the subpixel 5c arranged in one transmissive display area T by sewing the substantial center of the subpixel 5c arranged in the transmissive display area T in a plane. The sub-pixel 5b is connected to the sub-pixel 5b and the sub-pixel 5a disposed in the other transmissive display region T and the sub-pixel 5b disposed in the reflective display region R. In the inclined region (stepped portion or inclined portion) S, the sub-pixel connection portion of the pixel electrode 9 is electrically connected through the contact hole 7.

As shown in FIG. 9, a circular reflective electrode sub-pixel 5b is formed at the center of one dot region, and the region where the sub-pixel 5b is formed becomes a reflective display region R, and the connecting portion 8 A region where the sub-pixels 5a and 5c made of transparent electrodes electrically connected to both sides of the sub-pixel 5b of the reflective electrode are formed as a transmissive display region T. In addition, the insulating film 21 is formed so as to be wider than the formation region of the sub-pixel 5b of the reflective electrode in a band shape in one dot region in a direction along the capacitance line 3b when viewed in plan.
Further, since the portion where the connecting portion 8 for connecting each subpixel is present has a shape (notched portion K) that is notched to divide each subpixel, this notched portion K is a vertical that will be described later. It has a function as a slit for controlling the alignment of the liquid crystal molecules 50 ′ in the alignment (VA) mode.

  Next, a cross-sectional structure of the liquid crystal display device of the present embodiment will be described based on FIG. FIG. 10 is a cross-sectional view taken along the line AA ′ in FIG. 9 (one dot region or the longitudinal direction of the pixel electrode). The present invention is characterized by the structure of the insulating film 21 in the center of the dot region D. Furthermore, the connection structure for electrically connecting the TFT 30 and the pixel electrode 9 is characterized.

  As shown in FIG. 10, a liquid crystal layer 50 made of liquid crystal having an initial alignment state of vertical alignment is sandwiched between the TFT array substrate 10 and a counter substrate 25 disposed opposite thereto. In the TFT array substrate 10, scanning lines (gate lines) 3a and capacitance lines 3b are formed on the surface of a substrate body made of a translucent material such as quartz or glass. Further, the wiring portion 34 formed by wiring from the TFT 30 (drain 30D) through the insulating film is pulled to an inclined region (stepped portion or inclined portion) S having an inclined surface beyond the reflective display region R on the capacitor line 3b. It has been turned. Further, an insulating film 21 that substantially varies the thickness (dt, dr) of the liquid crystal layer 50 in each of the reflective display region R and the transmissive display region T is formed on the wiring portion 34. The reflective display region R is arranged at substantially the center of D, and the layer thickness dr of the liquid crystal layer 30 in the reflective display region R is made smaller than the layer thickness dt of the liquid crystal layer 50 in the transmissive display region T corresponding to this region ( An insulating film 21 is formed. The insulating film 21 may be formed integrally with the half-tone mask (gray mask) after the formation of the capacitor line 34 or by gradation exposure, or a portion protruding substantially toward the liquid crystal layer 50 (substantially). Only the portions where the thicknesses of the liquid crystal layers are different may be formed separately in separate steps. A portion protruding toward the liquid crystal layer 50 (a portion where the thickness of the liquid crystal layer is substantially different) corresponds to the reflective display region R, and the transmissive display region T is divided into two in the dot region D. The insulating film 21 is made of an organic film such as acrylic resin having a film thickness of about 2 to 3 μm, for example, and is inclined so that its layer thickness continuously changes in the vicinity of the boundary between the reflective display region R and the transmissive display region T. An inclined region (stepped portion or inclined portion) S provided with Since the thickness of the liquid crystal layer 50 in the portion where the insulating film 21 does not exist is about 4 to 6 μm, the thickness of the liquid crystal layer 50 in the reflective display region R is about half of the thickness of the liquid crystal layer 50 in the transmissive display region T. That is, the insulating film 21 functions as a liquid crystal layer thickness control layer that varies the thickness of the liquid crystal layer 50 between the reflective display region R and the transmissive display region T depending on its own film thickness. Further, the angle θ formed by the plane and the inclined surface of the insulating film 21 is about 10 ° to 50 °.

Therefore, the surface on the liquid crystal layer side of the insulating film 21 corresponding to the reflective display region R is provided with irregularities and is subjected to a rough surface treatment. Therefore, when the sub-pixel 5b functioning as a reflective electrode is formed on the aluminum (reflecting metal material) described later, the roughened unevenness is reflected on the surface, which is bright and good. Reflective characteristics can be obtained. However, at the interface with the alignment film on the liquid crystal layer side, the roughened irregularities are very fine so as not to affect the alignment control.
Further, the inclined region (stepped portion or inclined portion) S having an inclined surface of a portion protruding to the liquid crystal layer 50 side of the insulating film 21 (portion in which the layer thickness of the liquid crystal layer is substantially different) is provided. A contact hole 7 having a depth reaching the wiring portion 34 formed by wiring from the TFT 30 (drain 30D) is formed. Therefore, the contact hole 7 and the wiring portion 34 are electrically connected to the pixel electrode 9 and the TFT 30 by forming the connection portion 8 that electrically connects each subpixel. That is, the electrical connection between the TFT 30 and the pixel electrode 9 is such that the sub-pixel 5b of the reflective display region R that bisects the transmissive display region T by the wiring portion 34 and the contact hole 7 derived from the TFT 30 (drain 30D). It is the structure made | formed in the connection part 8 located in the both ends.

  Then, on the surface of the TFT array substrate 10 including the surface of the insulating film 21, island-shaped circular subpixels 5 a and 5 c are formed at positions corresponding to the transmissive display region T with indium tin oxide (Indium Tin Oxide, (Hereinafter abbreviated as ITO) or the like, and at the position corresponding to the reflective display region R, an island-like circular subpixel 5b is formed as a reflective electrode with aluminum (a metallic material having reflectivity). ing. Each sub-pixel is electrically connected, and the connection between the sub-pixel 5c arranged in one transmissive display region T and the sub-pixel 5b arranged in the reflective display region R, and the sub-pixel arranged in the reflective display region R. The connection between the pixel 5b and the sub-pixel 5a disposed in the other transmissive display region T is illustrated by a connection portion 8 formed in a linear shape. At this time, the contact hole 7 described above is arranged in the connection portion 8. And all this connection part 8 is located in the inclination area | region (step part or inclination part) S provided with the above-mentioned inclined surface. Further, the connection portion 8 may be formed integrally with these subpixels by the same ITO material as the subpixel 5a and subpixel 5c, and aluminum (having reflectivity) integrally with the subpixel 5b. (Metal material). In the latter case, light leakage from the inclined region (stepped portion or inclined portion) S that does not contribute to display can be prevented. In addition, in the electrical connection between the connection portion 8 for connecting the subpixels and / or the subpixel formed of ITO and the subpixel formed of aluminum (a reflective metal material), ITO and aluminum are used. An electrical connection can be easily achieved by superimposing one of the (reflective metal material) on the other. Thus, in one dot region D, the pixel electrode 9 composed of these subpixels 5a, 5b, and 5c is formed, and the vertical alignment film 12 is further formed thereon.

  On the other hand, the counter substrate 25 is provided with a color filter CFR for reflection display in a position overlapping in a plane in the reflection display region R, and a color filter CFT in transmission display in a position overlapping in a plane in the transmission display region T. Is provided. In general, in a transflective liquid crystal display device, light is transmitted twice through a color filter in reflective display, but is transmitted only once in transmissive display. Therefore, the saturation of display colors in reflective display and transmissive display. There is a problem that is different. In view of this, the present applicant has proposed a technique for changing the color purity of the dye layer of the color filter between the reflective display region R and the transmissive display region T and improving the balance of display colors between the reflective display and the transmissive display. In addition, the color purity of the color filter formed in the reflective display region R is formed by forming a non-colored region while keeping the color purity of the color layer of the color filter in the reflective display region R and the transmissive display region T the same. It is also possible to adopt a method of realizing a visually bright color display although it decreases and becomes light. Each of the dye layers of the reflective display color filter CFT and the transmissive display color filter CFT employs this technique.

  A transparent common electrode 11 made of ITO or the like is formed on the pigment layer of the color filter CFR for reflection display and the color filter CFT for transmission display. Here, the common electrode 11 is provided with alignment control means for controlling the alignment of the liquid crystal molecules 50 ′ of the liquid crystal layer 50. The orientation control means is provided at a planar position corresponding to the substantially center (center) portion of each subpixel formed on the TFT array substrate 10 side in the common electrode 11. This is due to the protrusion 13 made of a dielectric or the slit 14 having the common electrode 11 opened. In FIG. 10, the protrusions 13 made of a dielectric are shown as the orientation control means. Here, as shown in the first embodiment, the shape of the protrusion 13 or the slit 14 used as the orientation control means may be circular in the center with respect to the subpixel in a plane, or polygonal. The shape, cross shape, or x shape may be used. In particular, the liquid crystal molecules are continuously aligned if they are circular protrusions or slits in plan view, that is, the occurrence of disclination in which the alignment direction becomes discontinuous is suppressed, and it does not exist on the subpixel, so the transmittance A liquid crystal display device having a high viewing angle and a wide viewing angle can be provided.

  Although not shown, a circularly polarizing plate is provided on the outer surface side of the TFT array substrate 10, and a circularly polarizing plate is also provided on the outer surface side of the counter substrate 25. Further, although not shown, a backlight (illuminating device) is actually arranged on the back side of the TFT array substrate 10, and reflection display using external light (reflection arranged in the reflection display region R) is performed. It is a liquid crystal display device that realizes both display (display by subpixels made of electrodes) and transmissive display using light emitted from the backlight (display by subpixels made of ITO arranged in the transmissive display region T). Yes.

  Further, as shown in the first embodiment, the shape of each subpixel may be a square or an octagon. In this case, since the above-mentioned alignment control means is arranged in the center of each subpixel in a plane, in the case of a subpixel polygonal shape, the liquid crystal molecules tilt from the center in the subpixel toward each side. Will do.

  According to the liquid crystal display device of the present embodiment, the following effects are obtained in addition to the effects exhibited in the first embodiment. When the contact hole is formed in the center of the sub-pixel 5b in the reflective display region R as in the first embodiment, the flatness is impaired due to at least the influence of the depression of the contact hole when the alignment film is formed. As a result, the surface in contact with the liquid crystal layer is depressed, making it difficult to stably control the alignment of the liquid crystal molecules. However, by providing contact holes in the inclined region (stepped portion or inclined portion) S that does not contribute to display, reflection is achieved. The flatness of the surface on the liquid crystal layer side of the subpixel 5b in the display region R is ensured, and the liquid crystal molecules can be stably controlled even in the reflective display region R.

[Electronics]
Next, specific examples of the electronic apparatus including the liquid crystal display device according to the above embodiment of the present invention will be described.
FIG. 11 is a perspective view showing an example of a mobile phone. In FIG. 11, reference numeral 500 denotes a mobile phone body, and reference numeral 501 denotes a display unit using the liquid crystal display device.

  FIG. 12 is a perspective view showing an example of a portable information processing apparatus such as a word processor or a personal computer. In FIG. 12, reference numeral 600 denotes an information processing apparatus, reference numeral 601 denotes an input unit such as a keyboard, reference numeral 603 denotes an information processing apparatus body, and reference numeral 602 denotes a display unit using the liquid crystal display device.

  FIG. 13 is a perspective view showing an example of a wristwatch type electronic device. In FIG. 13, reference numeral 700 denotes a watch body, and reference numeral 701 denotes a display unit using the liquid crystal display device.

  Since the electronic apparatus shown in FIGS. 11 to 13 includes a display unit using the liquid crystal display device of the above embodiment, the liquid crystal display unit is bright, has high contrast, and has a wide viewing angle regardless of the use environment. The provided electronic device can be realized.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in the above embodiment, an example in which the present invention is applied to an active matrix liquid crystal display device using TFTs as switching elements has been described. However, an active matrix liquid crystal display device using thin film diode (TFD) switching elements, The present invention can also be applied to a passive matrix liquid crystal display device or the like. In addition, specific descriptions regarding materials, dimensions, shapes, and the like of various components can be appropriately changed.

  As described above in detail, according to the present invention, in the transflective liquid crystal display device, the problem of contrast reduction due to retardation difference in both the reflection and transmission display modes can be solved, and the liquid crystal molecules in the vertical alignment mode can be solved. Display defects due to the inability to control the orientation direction can be suppressed, and as a result, a liquid crystal display device with excellent display quality can be realized. Further, depending on the arrangement of the insulating film, an alignment division structure can be realized, and a wide viewing angle can be achieved.

FIG. 3 is an equivalent circuit diagram of a plurality of dots arranged in a matrix that forms an image display area of the liquid crystal display device according to the first embodiment of the present invention. 2 is a plan view showing the structure of a dot region of a TFT array substrate constituting the liquid crystal display device. FIG. FIG. 3 is a cross-sectional view showing the structure of the liquid crystal display device, taken along line A-A ′ of FIG. 2. It is the top view which showed the planar shape of the orientation control means (a slit or protrusion) arrange | positioned in the center part of a sub pixel planarly. 5 is a cross-sectional view showing alignment control by protrusions 13 and slits 14 of a liquid crystal layer having negative dielectric anisotropy. FIG. It is a top view which shows the structure of the dot area | region of the TFT array substrate of the other example of 1st Embodiment. It is a top view which shows the structure of the dot area | region of the TFT array substrate of the further another example of 1st Embodiment. It is a top view which shows the structure of the dot area | region of the TFT array substrate of the example which has arrange | positioned several sub pixel in each of a transmissive display area | region and a reflective display area | region in 1st Embodiment. It is a top view which shows the structure of the dot area | region of the TFT array substrate which comprises the liquid crystal display device of the 2nd Embodiment of this invention. FIG. 5 is a cross-sectional view showing the structure of the liquid crystal display device, taken along line A-A ′ of FIG. 4. It is a perspective view which shows an example of the electronic device of this invention. It is a perspective view which shows the other example of the electronic device of this invention. It is a perspective view which shows the further another example of the electronic device of this invention.

Explanation of symbols

9 pixel electrode 10 TFT array substrate 21 insulating film S inclined surface 25 counter substrate 11 common electrode 50 liquid crystal layer R reflective display area T transmissive display area

Claims (10)

A liquid crystal layer having negative dielectric anisotropy is sandwiched between a pair of substrates, and the electrodes formed on the opposing surface side of one of the pair of substrates and the opposing surface side of the other substrate are formed. A plurality of dot areas corresponding to the area overlapping with the pixel electrode are provided, and in each of the dot areas, a transmissive display area for performing transmissive display and a reflective display area for performing reflective display are individually provided, and the transmissive area is provided. A liquid crystal display device in which a layer thickness of the liquid crystal layer in the display region is set to be thicker than a layer thickness of the liquid crystal layer in the reflective display region,
The pixel electrode in one dot region is configured to have subpixels arranged in at least three or more regions in the longitudinal direction of the pixel electrode, and each subpixel has the transmissive display. A subpixel corresponding to the transmissive display region, the subpixel corresponding to the reflective display region, and the subpixel corresponding to the transmissive display region. Are arranged in this order in the longitudinal direction of the pixel electrode within one dot region.   Each pixel electrode is provided with a switching element that drives the pixel electrode, and each subpixel of the pixel electrode in one dot region is electrically connected, and the pixel electrode and the switching element 2. The liquid crystal display device according to claim 1, wherein electrical connection is made in the sub-pixel formed of a reflective film corresponding to the reflective display region.   The electrical connection between the switching element and the sub-pixel formed of a reflective film corresponding to the reflective display area is provided in a wiring portion wired from the switching element toward the reflective display area and the reflective display area. The liquid crystal display device according to claim 2, wherein the liquid crystal display device is connected through a contact hole. A liquid crystal layer is sandwiched between a pair of substrates, and corresponds to a region where an electrode formed on the opposite surface side of one substrate of the pair of substrates and a pixel electrode formed on the opposite surface side of the other substrate overlap. A plurality of dot areas, a transmissive display area for performing transmissive display and a reflective display area for performing reflective display are individually provided in the dot area, and the thickness of the liquid crystal layer in the transmissive display area is A liquid crystal display device set thicker than a layer thickness of the liquid crystal layer in the reflective display region,
On the surface of the one substrate on the liquid crystal layer side, there is a stepped portion or an inclined portion between the reflective display region and the transmissive display region having a different layer thickness of the liquid crystal layer. A switching element for driving the pixel electrode is provided, and the electrical connection between the pixel electrode and the switching element is connected through a contact hole provided in the stepped portion or the inclined portion. Liquid crystal display device.   5. The liquid crystal according to claim 1, wherein the electrode formed on the opposite surface side of the one substrate is formed with a slit that opens the electrode corresponding to each subpixel. Display device.   5. The electrode formed on the opposite surface side of the one substrate has a protrusion made of a dielectric formed on the electrode corresponding to each subpixel. The liquid crystal display device described.   The liquid crystal display device according to claim 5, wherein the protrusion or the slit is arranged in a plane at a substantially central portion of the subpixel.   On the surface of the one substrate on the liquid crystal layer side, there is a stepped portion or an inclined portion between the reflective display region and the transmissive display region having different layer thicknesses of the liquid crystal layer, and within one dot region 4. The liquid crystal display device according to claim 2, wherein the electrical connection of the sub-pixels of the pixel electrode is connected by a wiring formed on the stepped portion or the inclined portion.   9. The liquid crystal display device according to claim 1, wherein a shape of the sub-pixel in the one dot region is a regular polygon or a circle. An electronic apparatus comprising the liquid crystal display device according to claim 1.

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