CN100576035C - Semi-transmissive liquid crystal display device and color liquid crystal display device - Google Patents

Abstract

A semi-transmissive liquid crystal display device and a color liquid crystal display device are provided. The device seals a vertical alignment type liquid crystal layer between a first substrate with a first electrode and a second substrate with a second electrode; each pixel area has a reflective region and the transmissive region; on the first substrate side or the second substrate side, a gap adjustment part is provided, and the gap adjustment part makes the gap (dr) in the reflective region smaller than the gap (dt) in the transmissive region, and the gap (thickness of the liquid crystal layer, d) controls the retardation of light incident on the liquid crystal layer. In the pixel area, an alignment control unit that divides the liquid crystal alignment in a pixel area is provided on one or both of the first substrate side and the second substrate side. In addition, it is possible to optimize the gap by changing the gap with R, G, and B.

Description

Semi-transmissive liquid crystal display device and color liquid crystal display device

This application is a divisional application of the Chinese patent application with the application number 200510072215.5 and the filing date of May 23, 2005, and the invention title is "semi-transmissive liquid crystal display device and color liquid crystal display device".

field of invention

The present invention relates to a semi-transmissive liquid crystal display device in which each pixel is provided with a reflective area and a transmissive area.

Background technique

Liquid crystal display devices (hereinafter referred to as LCDs) are characterized by thinness and low power consumption, and are now widely used in displays such as computer monitors and portable information devices. This type of LCD seals liquid crystals between a pair of substrates, and displays by controlling the alignment of liquid crystals located between the substrates through electrodes formed on each substrate. This LCD is compatible with a CRT (cathode ray tube) display, electroluminescence (hereinafter Unlike EL) displays, which cannot emit light by themselves in principle, a light source is required in order to display an image to a viewer.

Therefore, in a transmissive LCD, a transparent electrode is used as an electrode formed on each substrate, and a light source is arranged on the back and side of the liquid crystal display panel, and the liquid crystal panel controls the light transmission amount of the light source, so even if the surrounding light is dark, Can also be displayed brightly. However, since the light source is always turned on for display, power consumption due to the light source cannot be avoided, or sufficient contrast cannot be ensured in an environment with strong light such as outdoors during the day.

On the other hand, in reflective LCDs, external light such as the sun or indoor lamps is used as a light source, and the ambient light incident on the liquid crystal panel is reflected by reflective electrodes formed on the substrate on the non-viewing surface side. Then, the amount of emitted light emitted from the liquid crystal panel by the light incident on the liquid crystal layer and reflected by the reflective electrode is controlled for each pixel to perform display. This kind of reflective LCD uses external light as the light source, so unlike the transmissive LCD, it has very low power consumption because there is no power consumption of the light source, and it can obtain sufficient power when it is bright outside the house. Contrast, on the other hand, has the property of not being able to see the display in the absence of external light.

Therefore, a kind of display that can be easily viewed outdoors and also observed in a dark place has recently been proposed, and has attracted attention, such as Japanese Patent Early Publication No. Hei 11-101992, Japanese Patent Early Publication No. 2003-255399, etc. The disclosed transflective LCD has reflection function and light transmission function. In the transmissive LCD, a transmissive area and a reflective area are provided in one pixel area, so as to simultaneously have a transmissive function and a reflective function.

In this way, it is very useful to use the above-mentioned transflective LCD as a display of, for example, a portable information device, because it can have both outdoor visibility and dark visibility.

However, in this portable information device and the like, various observation states are assumed, and in order to realize high-quality display even in various observation states (especially, various observation angles), it is necessary to expand the viewing angle.

In addition, since the semi-transmissive LCD divides a pixel into a transmissive area and a reflective area to achieve semi-transmissiveness, the transmissive and reflective properties of a pixel are lower than those of transmissive or reflective LCDs. , so in order to improve the display quality of each display area (transmissive area, reflective area), no matter which area must have a higher contrast.

However, with respect to transflective LCDs, improvements have been made only in structures that have both a transmissive function and a reflective function, and no attempt has been made to expand the field angle or improve the contrast in order to improve display quality.

Contents of the invention

The present invention aims at realizing high display quality of semi-transmissive LCD and color LCD.

(means to solve the problem)

The present invention can realize the aforementioned transflective LCD, and has the following features.

That is, it is a liquid crystal display device having a plurality of pixels, and a vertical alignment type liquid crystal layer is sealed between a first substrate having a first electrode and a second substrate having a second electrode; each pixel region has a reflective region and Penetrating region; in the aforementioned reflective region, at least one of the aforementioned first substrate side or the aforementioned second substrate side has a gap adjustment portion, in order to make the gap (gap) in the aforementioned reflective region larger than the gap in the aforementioned transmissive region Small, wherein the aforementioned gap controls the phase difference of incident light entering the liquid crystal layer and is regulated by the thickness of the liquid crystal layer; It has an alignment control section that divides the alignment direction of liquid crystal in one pixel area.

In this way, by using a vertically aligned liquid crystal layer in a transflective LCD, compared with, for example, well-known twisted nematic (TN, Twisted Nematic) liquid crystals, the responsiveness can be improved, and high-contrast display can be realized. Moreover, compared with the above-mentioned TN liquid crystals and the like that perform alignment control on the premise of adding a pretilt, in the vertical alignment type liquid crystal, since the alignment of the liquid crystal is controlled to be parallel or perpendicular to the plane of the substrate, the visual dependence is low in principle, Compared with TN liquid crystal, it can expand its viewing angle. Moreover, since the present invention is provided with an alignment control section that divides the liquid crystal alignment direction in a pixel area, even in the case of viewing the LCD from various angles, any divided area falls into The probability that the observation position is within the range of the most suitable viewing angle increases, and the viewing angle of one pixel can be further expanded. Therefore, regardless of whether the surrounding is dark or bright, high-speed and wide viewing angles can be used to achieve higher-contrast display.

In addition, even by simple calculation, it can be known that the total optical path length in the liquid crystal layer is different in the reflective region where the incident light passes through twice and the transmissive region where the incident light passes only once. In the pixel area, the most suitable liquid crystal layer thickness (cell gap) can be obtained in the reflective area and the transmissive area respectively. Therefore, there is no color shift or the like in the reflective area or the transmissive area, and optimal reflectance and transmittance can be realized, enabling a bright display with good color reproducibility.

In another aspect of the present invention, in the transflective LCD, the alignment control section includes an electrodeless section formed on either side of the first electrode or the second electrode, or both.

Alternatively, the alignment control unit may include a protruding portion that protrudes toward the liquid crystal layer from either or both of the first substrate side and the second substrate side. In addition, the electrodeless part and the protruding part can also be provided in one pixel area at the same time as the alignment control part.

In the transflective LCD, the end face of the gap adjustment part in the pixel region may further function as the alignment control part.

In other aspects of the present invention, in the aforementioned transflective LCD, the angle difference between the liquid crystal alignment azimuth controlled by the aforementioned alignment control unit in the pixel region and the liquid crystal alignment azimuth controlled by other alignment control units is less than 90 degrees, wherein the other alignment control portion has a projection line intersecting the projection line of the alignment control portion to the substrate plane.

By setting it to be less than 90 degrees, it is possible to reliably prevent the generation of disclination lines (disclination lines) (boundaries of regions with different alignment directions) at unspecified positions in one region divided by the alignment control unit, thereby preventing display irregularities. Qi et al.

In other aspects of the present invention, in the above-mentioned transflective LCD, the above-mentioned plurality of pixels include pixels for red, green, and blue, and in either or both of the transmissive area or the reflective area of each pixel , at least one of the pixels for red, green, and blue has a different gap from pixels of other colors.

In each pixel of red, green, and blue, the transmittance of light of different colors (R, G, B), that is, of different wavelengths is controlled by the liquid crystal layer. Therefore, the most suitable gap (thickness of the liquid crystal layer) varies according to the transmitted wavelength. In this case, a full color LCD having good color reproducibility without wavelength dependence can be easily obtained by changing pixels of different colors among R, G, and B pixels and their gaps. In addition, since the wavelength dependence can be reduced, the driving conditions of each pixel can be made equal, and the processing load on the driving circuit side can be reduced.

In another aspect of the present invention, in the transflective LCD, a quarter-wavelength plate and a half-wavelength plate are provided on the first substrate and the second substrate, respectively.

In this way, a quarter-wavelength plate and a half-wavelength plate are installed at the same time, combined with a linear polarizing plate, and used as a circular polarizing plate in a wide-wavelength band area, regardless of R, G, or B polarizing plates with different wavelengths. In any of the lights, necessary circularly polarized light can be more reliably obtained with respect to the vertical alignment type liquid crystal layer, and the wavelength dependence of the LCD can be further reduced.

In another aspect of the present invention, in the aforementioned transflective LCD, among the aforementioned first substrate and second substrate, on the side of the substrate opposite to the substrate disposed close to the light source, a phase element having a negative refractive index anisotropy is provided. bad board.

By setting this retardation plate (negative retarder, negative retarder) with negative refractive index anisotropy (optical anisotropy), the liquid crystal layer (liquid crystal unit) of the vertical alignment type can be optically compensated, and can further Expand the viewing angle of the LCD.

In another aspect of the present invention, in the transflective LCD, a biaxial retardation plate is provided on at least one of the first substrate or the second substrate. By adopting this kind of two-axis retardation plate, the functions of such as the aforementioned negative retarder (negative retarder), the aforementioned quarter-wavelength plate and the half-wavelength plate can be realized by this one retardation plate, and can realize It is thinner and minimizes light loss.

In another aspect of the present invention, in the aforementioned transflective LCD, the aforementioned first electrodes formed on the side of the aforementioned first substrate are formed in individual patterns in each pixel, and a plurality of them are formed on the side of the first substrate. The first electrodes are respectively connected to the thin film transistors, the second electrode formed on the second substrate side is formed as a common electrode common to each pixel, and the gap adjustment part is formed on the second substrate side.

If the gap adjustment part is formed on the second substrate, even in the case where thin film transistors and the like are formed on the first substrate side, the first substrate side can be formed by a common process for each pixel. Manufacturing of the first substrate is carried out in parallel, and it is suitable to form a gap adjustment portion on the side of the second substrate having a simpler structure than that of the first substrate, thereby improving the manufacturing efficiency.

In another aspect of the present invention, it is a liquid crystal display device including a plurality of pixels, and a vertical alignment type liquid crystal is sealed between a first substrate having a first electrode and a second substrate having a second electrode; The pixel region has a reflective region and a transmissive region, and at least one of the first substrate side or the second substrate side has a gap adjustment part for making the gap in the reflective region smaller than the gap in the transmissive region, wherein The gap controls the phase difference of incident light entering the liquid crystal layer and is defined by the thickness of the liquid crystal layer. The side surface of the gap adjustment layer has a tapered shape that expands in width toward the formation substrate of the gap adjustment layer.

By forming the side surface of the gap adjustment layer into a forward-slope taper shape in this way, it is possible to prevent disorder of liquid crystal alignment on the side surface, and to use the side surface as an inclined surface for alignment control.

As mentioned above, the present invention can obtain the enlargement of the viewing angle of the semi-transmissive LCD, and the improvement of the contrast ratio and the response speed, etc., so as to realize an LCD with high display quality.

In another aspect of the present invention, in a vertical alignment type liquid crystal display device having R, G, and B pixels for displaying the three primary colors of red, green, and blue, a first substrate on which pixel electrodes are formed for each of the pixels is provided. ; a second substrate configured opposite to the aforementioned first substrate and having a common electrode; a liquid crystal with negative dielectric anisotropy sealed between the aforementioned first substrate and the second substrate; on the aforementioned second substrate, corresponding to the aforementioned R, G , the R color filter layer, the G color filter layer and the B color filter layer configured for each pixel of B; the first vertical alignment film formed to cover the aforementioned pixel electrode; and the aforementioned common electrode and the aforementioned R, G, and B color filter layer to form the second vertical alignment film on the liquid crystal side. If the thicknesses of the aforementioned R-color filter layer, G-color filter layer and B-color filter layer are expressed as D-red, D-green, and D-blue respectively, then D-blue≥D-green≥D-red .

In another aspect of the present invention, it is a vertical alignment type liquid crystal display device provided with R, G, and B pixels for displaying the three primary colors of red, green, and blue. the first substrate; the second substrate configured opposite to the first substrate and having a common electrode; the liquid crystal with negative dielectric anisotropy sealed between the first substrate and the second substrate; on the second substrate, the corresponding The R color filter layer, the G color filter layer and the B color filter layer configured by the aforementioned R, G, and B pixels; the gap layer selectively formed on the aforementioned G color filter layer and the B color filter layer a first vertical alignment film formed to cover the aforementioned pixel electrodes; and a second vertical alignment film formed on the side of the liquid crystal layer relative to the aforementioned common electrode, the aforementioned R, G, and B color filter layers, and the aforementioned gap layer.

By adopting such a relationship and configuration, in a color vertical alignment type liquid crystal display device having pixels for displaying R, G, and B, low power consumption can be realized regardless of any of the three primary colors of R, G, and B, and Display without color shift.

Description of drawings

1 is a schematic diagram showing a schematic cross-sectional structure of a vertical alignment type transflective LCD according to a first embodiment of the present invention;

2 is a schematic diagram showing other schematic cross-sectional configurations of the vertical alignment type transflective LCD according to the first embodiment of the present invention;

3 is a schematic plan view showing a more specific transflective LCD according to the first embodiment of the present invention;

Fig. 4 is a schematic diagram of a schematic cross-sectional view of a transflective LCD at a position along the line A-A' of Fig. 3;

Fig. 5 is a schematic diagram of a schematic cross-sectional view of a transflective LCD at a position along the B-B' line of Fig. 3;

6 is a schematic cross-sectional view showing the configuration of a pixel electrode of the transflective LCD shown in FIG. 3 and a TFT connected thereto;

FIG. 7 is a schematic plan view of a transflective LCD different from FIG. 3 according to an embodiment of the present invention;

Fig. 8 is a schematic diagram of a schematic cross-sectional configuration of a transflective LCD at a position along the line C-C' of Fig. 7;

9 is a schematic diagram showing a schematic planar configuration of a modified example of the transflective LCD of FIG. 3;

10 is a schematic diagram showing a schematic planar configuration of another modified example of the transflective LCD of FIG. 3;

11 is a schematic diagram of the relationship between the transmittance characteristics of the vertical alignment transflective LCD with respect to the applied voltage and the cell structure according to the first embodiment of the present invention;

12 is a schematic diagram of the wavelength dependence of the transmittance characteristics of the vertical alignment semi-transmissive LCD with respect to the applied voltage according to the first embodiment of the present invention;

13 is a schematic diagram of the wavelength dependence of the transmittance characteristic with respect to the applied voltage after adjusting the liquid crystal cell gap with R, G, and B in the vertical alignment transflective LCD according to the first embodiment of the present invention;

14 is a chromaticity coordinate showing the dependence of the chromaticity on the applied voltage of the vertical alignment type transflective LCD according to the first embodiment of the present invention;

15 is the chromaticity coordinates of the dependency of the chromaticity with respect to the applied voltage after adjusting the liquid crystal cell gap by R, G, and B in the vertical alignment transflective LCD according to the first embodiment of the present invention;

16 is a cross-sectional view of a vertical alignment liquid crystal display device according to a second embodiment of the present invention;

17A, 17B, and 17C are schematic diagrams showing the relationship between the V-T characteristics of each RGB pixel and the gap between liquid crystal cells;

18 is a cross-sectional view of a vertical alignment liquid crystal display device according to a third embodiment of the present invention;

19A, 19B, and 19C are schematic diagrams showing the relationship between the V-T characteristics of RGB pixels and the gap between liquid crystal cells.

[Description of main component symbols]

20 active layer 30 gate insulating film

32 Gate electrode 34 Interlayer insulating film

36 drain electrode 38 planarization insulating film

40 source electrode 42 metal layer

44 reflective layer 100 first glass substrate

110 circular polarizer 111λ/4 plate

112 polarizer 200 second glass substrate

210 transparent electrode 220 reflective electrode

260 alignment film 300 second glass substrate

310 phase difference plate 320 transparent common electrode

330, 330r, 330g, 330b color filter layer

330BM black light shielding layer 340 clearance adjustment part

400 liquid crystal layer 410 liquid crystal pointing

500 (530) alignment control part 510, 510t, 510r protrusion

520 inclined part 600 light source

Detailed ways

Preferred embodiments of the present invention (hereinafter referred to as "embodiments") will be described below using the drawings.

first embodiment

FIG. 1 shows a basic cross-sectional configuration when a semi-transmissive active matrix (Active matrix) LCD is used as the transflective LCD of this embodiment. The transflective LCD of this embodiment has a plurality of pixels, and the first and second substrates on which the first electrode 200 and the second electrode 320 are formed on opposite sides of each other are arranged with the liquid crystal layer 400 interposed therebetween. It is formed by sticking together, and at the same time, a transmissive area 210 and a reflective area 220 are formed in each pixel area.

A vertically aligned liquid crystal with negative dielectric anisotropy is used as the liquid crystal layer 400, and an alignment control part 500 (alignment control part 500) for dividing one pixel region into a plurality of alignment regions is provided on the second substrate side or the first substrate. Division). The alignment control unit 500 is composed of, for example, a protruding portion 510 protruding toward the liquid crystal layer 400 as shown in FIG. described).

Transparent substrates such as glass are used for the first and second substrates 100 and 300 . On the side of the first substrate 100, a pixel electrode 200 in an individual pattern of each pixel is formed using transparent conductive metal oxides such as indium tin oxide (ITO, Indium Tin Oxide) and indium zinc oxide (IZO, Indium Zinc Oxide). As the first electrode, and a switching component such as a thin film transistor connected to the pixel electrode 200 (not shown. Refer to FIG. 5 described later). A vertical alignment type alignment film 260 is formed on the entire surface of the first substrate 100 covering the pixel electrodes 200 . The alignment film 260 is made of, for example, polyimide. In this embodiment, a rubbingless type is used, and the initial alignment of the liquid crystal (alignment in a state where no voltage is applied) is perpendicular to the plane direction of the film. Moreover, with the structure shown in FIG. 5 (details will be described later), a transparent region 210 composed only of the above-mentioned transparent electrodes can be provided in the formation region of one pixel electrode 200, and a transparent region 210 formed by laminating with the above-mentioned transparent electrodes can be formed. The reflective film or the reflective region 220 of the reflective electrode.

In the second substrate 300 bonded to the first substrate 100 with the liquid crystal layer 400 interposed therebetween, the R, G, and B color filter layers 330r, 330g, and 330b are first placed on the side opposite to the liquid crystal. formed at corresponding predetermined positions. Furthermore, a light shielding layer (here, a black color filter layer) 330BM for preventing light leakage between pixels is provided in the gaps (gap between pixel regions) of the color filter layers 330r, 330g, and 330b.

A gap adjustment portion 340 made of a light-transmitting material is formed on the color filter layers 330r, 330g, and 330b, so that the thickness of the liquid crystal layer (cell gap) dr It is a desired value (dr<dt) smaller than the thickness of the liquid crystal layer (cell gap) dt in the transmissive region 210 . The thickness of the gap adjustment part 340 corresponds to the thickness of the liquid crystal layer required to obtain the most suitable transmittance and reflectance in the transmissive region 210 where the incident light passes through the liquid crystal layer 400 once and the reflective region 220 where it passes twice. It is set according to different situations of d. Therefore, for example, the thickness d of the liquid crystal layer is determined so that the most suitable transmittance can be obtained in the transmissive region 210 where the gap adjusting part 340 is not provided, and in the reflecting region 220, by setting the gap adjusting part with a desired thickness 340, so that the thickness d of the liquid crystal layer smaller than that of the penetrating region 210 can be obtained.

An electrode (common electrode) 320 common to each pixel is formed as a second electrode so as to cover the entire surface of the second substrate 300 having the gap adjustment portion 340 . The common electrode 320 is the same as the pixel electrode 200 described above, and can be formed using transparent conductive metal oxides such as ITO and IZO.

In this embodiment, the protrusion 510 is formed on the common electrode 320 as the alignment control portion 500 that divides the liquid crystal alignment direction in one pixel region to form a plurality of regions with different alignment directions. The protruding portion 510 protrudes toward the liquid crystal layer 400 and may be conductive or insulative. Here, an insulating resin such as acrylic resin can be formed into a desired pattern and used. Moreover, the protruding part 510 is respectively formed in the transmissive area 210 and the reflective area 220 in each pixel area.

A frictionless type alignment film 260 must be formed to cover the protruding portion 510 and the common electrode 320 , which is the same vertical alignment type as that on the first substrate side. As described above, the alignment film 260 aligns the liquid crystal in a direction perpendicular to the plane direction of the film, and a slope reflecting the shape of the protrusion 510 is formed at the position covering the protrusion 510 . Therefore, at the position where the protrusion 510 is formed, the liquid crystal is aligned in a vertical direction with respect to the slope of the alignment film 26 covering the protrusion 510 , and the alignment direction of the liquid crystal is divided by the protrusion 510 . In addition, in this embodiment, the side surface of the gap adjustment portion 340 disposed on the second substrate side is inclined into an oblique cone shape, and the alignment film 260 covering the gap adjustment portion 340 is also formed with a slope extending from the slope. The liquid crystal is also controlled to be perpendicular to the slope on the slope, and the slope of the gap adjustment part 340 is also used as the alignment control part 500 .

In the transflective LCD shown in FIG. 1 , a linear polarizer (first polarizer) 112, and a λ/4 phase difference plate and a λ/2 The wide-wavelength band λ/4 plate (first retardation plate) 111 constituted by a combination of retardation plates, and the wide-wavelength band circular polarizing plate 110 is composed of the linear polarizer 112 and the retardation plate 111 .

On the outer side (observation side) of the second substrate 300, a retardation plate 310 having a negative refractive index anisotropy is provided as an optical compensation plate, and a wide-angle plate composed of a combination of a λ/4 phase plate and a λ/2 phase plate is also provided. The wavelength band λ/4 plate (second retardation plate) 111 and the linear polarizer (second polarizer) 112 are the same as the first substrate side, and the linear polarizer 112 and the retardation plate 111 form a wide band region. Circular polarizer 110. Here, the configuration relationship of these optical components can be shown as an example in the lower part of Fig. The retardation axes of the two λ/4 plates are arranged at 180°, and the axis of the second polarizing plate is arranged at 135°.

The linearly polarized light emitted from the light source 600 and passing through the linear polarizing plate 112 on the side of the first substrate 100 along the polarization axis direction of the polarizing plate 112 is obtained by shifting the phase difference by λ/4 at the first λ/4 plate 111. become circularly polarized. Here, in this embodiment, in order to ensure circularly polarized light for at least any components of R, G, and B with different wavelengths, and to improve the light utilization efficiency (transmittance) in the liquid crystal cell, λ is used Both the /4 phase plate and the λ/2 phase plate serve as the wide wavelength band λ/4 plate 111 . The obtained circularly polarized light penetrates the pixel electrode 200 in the transmission area 210 and enters the liquid crystal layer 400 .

In the transflective LCD of this embodiment, as described above, the vertical alignment type liquid crystal having negative dielectric anisotropy (Δε<0) is used for the liquid crystal layer 400 , and the vertical alignment type alignment film 260 is used.

Therefore, in the state where the voltage is not applied, they are respectively aligned in a direction perpendicular to the plane direction of the alignment film 260, and as the applied voltage increases, the long axis direction of the liquid crystal is in the same direction as that formed between the pixel electrode 200 and the common electrode 320. The electric field is tilted in a vertical (parallel to the plane direction of the substrate) manner. When no voltage is applied to the liquid crystal layer 400 , the polarization state does not change in the liquid crystal layer 400 , and the circularly polarized light reaches the second substrate 300 directly, and the circularly polarized light is eliminated by the second λ/4 plate 111 to become linearly polarized light. At this time, because the second polarizer 112 is arranged so that it is perpendicular to the direction of the linearly polarized light from the second λ/4 plate 111, the linearly polarized light cannot pass through the direction perpendicular to the first polarizer 112. The second polarizer 112 of the transmission axis (polarization axis) makes the display black.

After a voltage is applied to the liquid crystal layer 400, the liquid crystal layer 400 causes the incident circularly polarized light to generate a phase difference, for example, to become reversed circularly polarized light, elliptically polarized light, or linearly polarized light, and the obtained light is further polarized by the second λ/4 plate 111 Shift the phase by λ/4 to become linearly polarized light (parallel to the transmission axis of the second polarizer), elliptically polarized light, and circularly polarized light. These polarized lights have components along the polarization axis of the second polarizer 112, and the light corresponding to this component is The second polarizer 112 emits light toward the observation side, and is recognized as a display (white or halftone).

Furthermore, the phase difference plate 310 is a negative retarder, which can improve the optical characteristics when viewing the LCD from an oblique direction, thereby increasing the viewing angle. Furthermore, instead of the negative retarder (310) and the above-mentioned λ/4 plate 111, a single two-axis retardation plate having both functions can be used, thereby realizing thinning of LCD and improvement of transmittance.

In this embodiment, as described above, the thickness d of the liquid crystal layer 400 (cell gap) that substantially controls the transmittance of light is set to have a difference between the transmissive region 210 and the reflective region 220 through the gap adjusting part 340 . expected gap. The main reason is that, in the penetrating region 210, the light source 600 that is arranged on the back side of the LCD (the first substrate 100 side in FIG. 1 ) penetrates the liquid crystal layer 400 and is emitted from the second substrate 300 side to the outside. The amount of light (transmittance) is controlled to display, and in the reflective area 220, the light incident on the liquid crystal layer 400 from the viewing side of the LCD is reflected by the reflective film provided in the area where the pixel electrode 200 is formed, and then again The amount of light (reflectivity of the LCD) that penetrates the liquid crystal layer 400 and exits from the second substrate side to the viewing side is controlled to perform display, and the number of times the light passes through the liquid crystal layer varies. That is, since the light in the reflective region 220 passes through the liquid crystal layer 400 twice, the cell gap dr must be set smaller than the cell gap dt in the transmissive region 210 . In this embodiment, as shown in FIG. 1 , the aforementioned dr<dt is achieved by disposing the gap adjusting portion 340 with a desired thickness only in the reflection region 220 of each region. The gap adjusting part 340 is not particularly limited as long as it has light transmission and can be formed into a desired thickness. For example, acrylic series resin used as a planarization insulating layer and the like can be used.

When the side surface of the gap adjustment part 340 is used as a part of the alignment control part 500 (inclined part 520) as described above, at least the taper angle must be less than 90 degrees with respect to the substrate plane. The reason is that if the oblique cone angle is more than 90 degrees, the alignment of the liquid crystal will be disturbed on the side of the gap adjustment part 340, and the coverage of the common electrode 320 and the alignment film 260 formed on the gap adjustment part 340 will also become insufficient. full. In addition, the side surface of the gap adjustment part 340 has no effect on the display itself. If the oblique cone angle is too small, the area of the side surface of the gap adjustment part 340 will be increased, resulting in the aperture ratio of the pixel, especially the reflective area where it is desired to increase the brightness. The opening rate decreased. Therefore, the oblique taper angle of the side surface of the gap adjustment part 340 is preferably an angle that does not reduce the coverage of the upper layer of the second electrode 320 and the alignment film 260, and enables alignment and division of liquid crystals, and reduces the aperture ratio less. . Specifically, a range of 30° to 80° is preferable.

The inclined portion 520 can be, for example, the aforementioned acrylic resin containing a photosensitive agent as the gap adjusting portion 340 having a taper angle in this range. Then, the gap adjustment material can be formed into an arbitrary forward taper angle by adjusting the content of the polymerization initiator added to the acrylic resin as a gap adjustment agent and the content of the photopolymerizable monomer in accordance with the manufacturing conditions and the characteristics of the exposure device. . In order to make the side surface of the gap adjustment part 340 into a forward-sloping cone, in addition to adjusting the containing material in this way, for example, the following methods can also be used alone or in combination: using the photopolymerization inhibitory effect caused by the oxygen present in the surroundings, using the light during exposure The expansion of the pattern caused by continuous shooting, the use of melt flow caused by resin baking, etc., can form a beveled cone with a desired angle.

The photopolymerization inhibitory effect is obtained by the oxygen in the atmosphere near the surface of the gap adjustment part 340. Conversely, since the substrate side farther from the surface has less oxygen, there is no inhibitory effect and the hardening due to polymerization continues. Therefore, it is easy to remove the surface side of the planarizing insulating layer 38 during development, and form a forward-slope cone whose width becomes narrower as it goes upward.

Diffraction of light during exposure is also used in the exposure device. For example, in a proximity exposure device, etc., an oblique cone is formed in the gap adjustment part 340 by the gap adjustment part forming region and the removal region by utilizing the large diffraction effect.

In the melt flow, after the development is completed, for example, bake at a temperature of 80° C. to 180° C. for 1 to 20 minutes (for example, at 120° C. for 8 minutes), so that the upper surface and side surfaces of the gap adjustment portion 340 are melted, While smoothing the surface, the shape of the side surface changes depending on the surface tension of the molten material itself to form a forward-sloping cone.

Here, the organic material used for the gap adjustment part and the like is a known material having sensitivity to g-line (436nm), h-line (405)nm, i-line (248nm) of the exposure light source, etc. The oblique cone angle of sensitive organic materials is generally more than 90 degrees (reverse oblique cone). Therefore, in this embodiment, the gap adjustment part is made of acrylic resin that is sensitive to g-line and h-line and can easily form a forward-sloping cone.

In this embodiment, in a pixel area, the thickness d of the liquid crystal layer is changed in the transmissive area 210 and the reflective area 220, and at the same time, the thickness d of the liquid crystal layer is changed in the R, G, and B pixels with different wavelengths ( However, it is also possible to set a common gap for R, G, and B according to the characteristics of the LCD). In the example of FIG. 1, by changing the thicknesses of the color filter layers 330r, 330g, and 330b of R, G, and B respectively formed on the second substrate 300 side, it is possible to realize the gap between all R, G, and B. d. It is not limited to the structure of changing the thickness of the color filter layer, and the above-mentioned gap adjustment part 340 can also be provided in the transmission area 210, and the gap adjustment part 340 can be changed between the transmission area 210 and the reflection area 220 of each R, G, and B. thickness. In addition, in all R, G, and B, even if the thickness d of the liquid crystal layer is not made different from each other, it is also possible to use the same liquid crystal layer thickness for G and B according to the characteristics of the LCD, and only for R and the other two. It is also possible to change only d for B if the thickness is different.

FIG. 2 shows another configuration in which pixels for R, G, and B have different gaps (in FIG. 2 , the same configuration as that in FIG. 1 will not be repeated). In the configuration of FIG. 2 , the gaps of R, G, and B are not changed on the second substrate side, and the thickness of the planarizing insulating layer 38 formed on the lower layer of the pixel electrode 200 is changed to R, G, and B on the first substrate 100 side. Adjustment. The method of changing the thickness of the planarizing insulating layer 38 includes, for example: using a single or multiple half-exposure masks corresponding to the opening amount of the target thickness to expose the planarizing insulating material containing the photosensitive material without adding a special process. A planarization insulating layer 38 having a different thickness is formed at each of the R, G, and B pixels. Furthermore, in FIG. 2 , the reflection region is formed with unevenness on the planarization insulating layer 38 . The irregularities on the surface of the planarizing insulating layer 38 can make the reflective layer 44 formed on the planarizing insulating layer 38 in the reflective region continue this shape, and form irregularities on the surface of the reflective layer 44, so that the incident light incident on the liquid crystal layer Scattering, improves the display quality of reflective areas. In addition, the half-exposure for forming the planarization insulating layer 38 to have different thicknesses in the above-mentioned R, G, and B can also be used to form together without adding a process. A contact hole is formed through the planarization insulating layer 38 to connect the pixel electrode 200 and the TFT.

Next, the specific structure of each pixel of the transflective LCD of this embodiment will be described. Fig. 3 is an example of the basic plane constitution of the transflective LCD of the present embodiment, Fig. 4 is the basic sectional structure along the A-A ' line of Fig. 3, and Fig. 5 is the basic sectional structure along the B-B' line of Fig. 3, Fig. 6 represents the specific configuration of the pixel electrode 200 in FIG. 3 and the thin film transistor connected thereto.

In the planar structure shown in FIG. 3, the pixel electrode 200 of the individual pattern of each pixel has an elongated hexagonal pattern in the vertical scanning direction of the screen (up and down direction in FIG. In the quadrangular (rhombic or square in the figure) area surrounded by oblique lines in the figure, as shown in FIG. 6 , a reflective film is selectively formed, and a reflective area 220 is provided. In addition, the rest of the hexagonal pixel electrode 200 which is roughly arrow-feather-shaped becomes the penetrating region 210 .

As can also be understood from FIG. 4 , in order to make the thickness (cell gap) dr of the liquid crystal layer in the reflective region 220 smaller than the gap dt in the transmissive region 210, the gap adjustment layer 340 is formed on the second substrate 300, In the example of FIG. 4 , it is formed on the common electrode 320 .

The end portion of the gap adjustment layer 340 in the pixel is arranged along the lower two sides of the quadrangular reflective region 220 substantially line-symmetric to the two upper sides of the hexagonal pixel electrode 200 . In addition, the reflective region 220 is divided into upper and lower parts in the horizontal scanning direction by connecting the opposing vertices of the quadrangular reflective region 220 in the horizontal scanning direction (left and right directions in the figure). 4 is the gap adjustment part 340) formed with a triangular cross-sectional protrusion 510r.

Also, although omitted in FIG. 4 , as shown in FIGS. 1 and 2 , the entire surface of the second substrate 300 including the protruding portion 510 and the gap adjusting portion 340 is covered with the vertical alignment film 260 . Of course, the vertical alignment film 260 is also formed on the entire surface side of the pixel electrode 200 including the side of the first substrate 100 as in FIG. 1 and FIG. 2 . Therefore, in a state where no voltage is applied between the pixel electrode 200 and the common electrode 320 , the long axis direction (liquid crystal director) 410 of the liquid crystal is vertically aligned with respect to the plane direction of the vertical alignment film 260 . Thus, on the side of the second substrate 300, on the slopes of the protruding portion 510 and the gap adjusting portion 340, the liquid crystal pointing 410 is vertically aligned with respect to the slope of the alignment film 260 formed on the side opposite to the liquid crystal along these slopes. . Therefore, as shown in FIG. 3 and FIG. 4 , regions in which alignment angles (orientation orientations) of liquid crystals differ by 180° from each other are formed on the boundary of protrusions 510 r that divide reflection region 220 into upper and lower positions.

Next, as shown in FIG. 3 and FIG. 5 , in the penetrating region 210 in the shape of an arrow feather, in the vertical scanning direction, the elongated hexagonal pixel electrode 200 is equally divided into left and right sides (horizontal scanning direction) in the vertical scanning direction (equivalent to At the center of the fletch), a protrusion 510 t having a triangular cross-section is formed on the second substrate 300 side (specifically, on the common electrode 320 ). Although omitted in FIG. 5 as in FIG. 4 , a vertical alignment film 260 as shown in FIGS. In the penetrating region 210, the alignment direction (orientation orientation) of the liquid crystal pointer 410 is divided into directions different from each other by 180° with the protrusion 510t formed on the second substrate 300 as a boundary.

In addition, in this embodiment, not only the above-mentioned protrusions and slopes are used, but also the non-electrode region 530 is used as the alignment control part 500. In the examples shown in FIGS. The gap part is used as the electrodeless part 530 for alignment control. The alignment division by the electrodeless portion 530 utilizes the inclination of the weak electric field when the voltage application starts between the pixel electrode 200 and the common electrode 320 . Under this weak electric field, as shown in FIGS. 4 and 5 , the lines of electric force indicated by dotted lines incline so as to widen from the end of the electrodeless part (that is, the end of the electrode) toward the center of the electrodeless part. Then, the short axis of the liquid crystal having negative dielectric anisotropy is aligned along the inclined electric force lines, and therefore, the direction of the gradient in which the liquid crystal molecules rise from the initial homeotropic alignment state to the applied voltage of the liquid crystal is determined by the inclined electric field.

In the hexagonal pixel electrode 200 shown in FIG. 3 , there is an end portion of the pixel electrode 200 , that is, an electrodeless portion 530 having at least six sides. Therefore, due to the effects of the protrusions 510 (510r, 510t) and slopes 520 and the electrodeless portion 530 around the pixel electrode 200 in the liquid crystal pointing 410, at least two alignment regions are formed in the reflective region 220 in a pixel region. The penetrating region 210 forms two alignment regions having different alignment azimuths from any of the two regions of the reflection region 220 described above, that is, four regions having different alignment directions are formed in total.

More precisely, the liquid crystal pointing 410 is controlled so that its plane component (orientation azimuth) is perpendicular to the extending direction of the protrusion 510 and the extending direction of the edge of the electrode (electrodeless portion). Therefore, even in the above-mentioned four alignment regions, the alignment azimuth angles of liquid crystals in one region are not completely the same. For example, in FIG. 3 , in the middle of the vertical scanning direction of the penetrating region 210 , the liquid crystal pointing 410 is aligned vertically with respect to the protrusion 510 t extending along the vertical scanning direction and the edge of the pixel electrode 200 . However, at the boundary of the penetrating area 210 with the reflective area 220, for example, the inclined part (protrusion) 520 of the gap adjustment part 340 intersects the protruding part 510t of the penetrating area 210 at an angle greater than 90 degrees. The alignment azimuth of the liquid crystal near the intersection is changed from the direction perpendicular to the extending direction of the protrusion 510 to the direction perpendicular to the extending direction of the inclined portion 520 by the inclined portion 520 of the gap adjusting portion 340 . However, in an alignment region, as will be described later, the extension direction of the alignment control part 500 is set so that the degree of change (or maximum angle) of the alignment azimuth angle of the liquid crystal is small, so that it is possible to prevent the An indeterminate position of an alignment region produces a junction (disclination line) of regions with different alignment azimuths of the liquid crystal.

Next, the relationship between the extending direction of the alignment control unit 500 and the alignment azimuth angle of the liquid crystal in each position in one pixel region of the present embodiment will be described.

Since the liquid crystal molecules have no difference in vertical characteristics in the long axis direction, the alignment azimuth of the liquid crystal controlled by the protrusion 510t of the transmissive region 210 and the orientation angle of the liquid crystal controlled by the slope 520 of the gap adjustment part 340 intersecting the protrusion 510t The angle difference of alignment azimuth angle is smaller than 90 degree, in the example of Fig. 3, the intersecting angle of protruding part 510 and the inclined part 520 of utilization gap adjustment part 340 is about 135 degree, and to this, the difference of the alignment azimuth angle of liquid crystal is 45 degree. Furthermore, here, the protruding portion 510t intersects with the gap adjustment portion 340 as an example for description, but there are also cases where they do not physically intersect. In this specification, the so-called intersecting refers to the intersecting of the respective extension lines. In addition, when When they are provided on different substrates, it means that the projection lines of the respective extension lines to the plane of the same substrate intersect.

In addition, the crossing angle between the inclined portion 520 of the gap adjusting portion 340 and the side of the pixel electrode 200 in the penetrating region 210 is used (however, since the inclined portion 520 and the pixel electrode 200 are not actually formed on the same substrate, they are respectively In the example of FIG. 3 , the intersection angle of projection lines directed to the same substrate plane is about 45 degrees. The angle between the alignment azimuth angle of the liquid crystal controlled by the slope portion 52 and the alignment azimuth angle of the liquid crystal controlled by the edge of the pixel electrode 200 is still less than 90 degrees, which is an angle smaller than 45 degrees here.

The intersecting angle between the projected portion 510t near the lower end of the penetrating region 210 and the projection line of the edge of the pixel electrode 200 toward the substrate plane is 45 degrees here. Since the liquid crystal molecules have no vertical difference similar to the above, the cross attachment The difference in alignment azimuth angles of liquid crystals is smaller than 90 degrees, and here is 45 degrees or less.

There is also a region where the sides of the pixel electrode 200 cross each other in the penetration region 210 . In the example of FIG. 3 , it refers to the side extending along the vertical scanning direction, and the side extending from the apex intersecting with the above-mentioned protrusion 510 toward the side extending along the vertical scanning direction, and the intersection angle of the two sides is larger than 90 degrees. is 135 degrees. However, the difference in alignment azimuth angle of the liquid crystal at the crossing portion is also 45 degrees, which is smaller than 90 degrees here, because the liquid crystal molecules have no vertical difference.

Similarly, in the reflective region 220, in the region where the projection line (including the extension line) of the alignment control part 500 toward the substrate plane intersects the projection lines (including the extension line) of other alignment control parts 500 toward the same substrate plane, so that the liquid crystal The alignment control unit 500 is provided so that the difference between the alignment azimuth angles is smaller than 90 degrees. That is, first, the protrusion 510 r that divides the alignment direction up and down in the reflective region 220 intersects the inclined portion 520 of the gap adjustment portion 340 intersecting at the end of the pixel electrode 200 at an angle smaller than 90 degrees. The angle difference of the alignment azimuth angle of the liquid crystal is controlled to be 45 degrees or less which is smaller than 90 degrees.

The intersecting angle (the intersecting angle of the projection line toward the substrate plane) between the protruding portion 510r and the edge of the pixel electrode 200 in the reflective region 220 is also controlled to be less than 90 degrees, and the angle difference between the alignment azimuth angles of the liquid crystals at these intersecting portions is also equal to The above-mentioned same control is below 45 degrees which is smaller than 90 degrees.

As described above, when the projection lines of the alignment control sections 500 on the substrate plane intersect each other, the alignment control section is determined so that the difference between the alignment azimuth angles of the liquid crystals controlled by these alignment control sections 500 is less than 90 degrees. 500 (projection portion 510, slope portion 520, electrodeless portion (in the example of FIG. 3, the shape of the pixel electrode 200) 530). Accordingly, it is possible to reliably prevent disclination lines from being generated at indeterminate positions within a region divided by the alignment control unit 500 .

Furthermore, in the position where the sides of the pixel electrode 200 in the reflective region 220 intersect each other (in FIG. In the example of Fig. 3, the crossing angles between the intersections (near the V-shaped joints) are all 90 degrees. Of course, it is better to set the intersection angle to be smaller than 90 degrees or larger than 90 degrees from the above-mentioned point of view, but since the area of the rhombic reflection region 220 itself is smaller than that of the transmission region 210, it is possible to prevent the occurrence of a crossover angle at an indeterminate position. disclination line.

Since the liquid crystal in the reflective area 220 is strongly controlled by the alignment of the protruding portion 510r, the inclined portion 420, and the side of the pixel electrode 200, the intersection point connecting the side of the electrode 200 of the reflective area 220 and the inclined surface of the gap adjustment portion 340 There is no physical alignment control part 500 on the oblique line of the rhombic reflective region 220 at the intersection point of the part 520 . However, receiving equal control from the adjacent alignment control unit 500 and the influence of both the continuum of the liquid crystal controlled to be perpendicular to the extending direction of the protrusion 510r, the plane component of the liquid crystal pointing 410 at this position As shown in FIG. 3 , it becomes a direction along the vertical scanning direction. Then, as the position approaches the end of the pixel electrode in the horizontal scanning direction, the liquid crystal is controlled by the side (530) of the pixel electrode 200, the direction in which the slope 520 of the gap adjustment part 340 extends, and the protrusion 510r. The orientation is slightly deviated from the direction perpendicular to these extending directions (less than 90 degrees, less than 45 degrees in the example of FIG. 3 ). Therefore, generation of disclination lines at indeterminate positions can be prevented even in the reflection region 220 .

Next, as shown in FIG. 6 , the configuration and manufacturing method of the pixel electrode 200 and the thin film transistor TFT connected to the pixel electrode will be described. In this embodiment, as described above, it is a so-called active matrix type LCD in which each pixel has a thin film transistor, and as shown in FIG. Thin film transistor TFT. In addition, because it is to arrange the transmissive region 210 and the reflective region 220 as efficiently as possible in a pixel region, especially not to reduce the aperture ratio of the transmissive region 210, it is generally formed in a light-shielding area in a transmissive LCD. The TFTs in the region are arranged in the reflective region 220 which does not affect the aperture ratio even if the TFTs are provided.

In this embodiment, a top gate type TFT is used, and polycrystalline silicon (p-Si) obtained by polycrystallizing amorphous silicon (a-Si) by laser annealing is used as the active layer 20 . Of course, the TFT is not limited to p-Si of the top gate type, but may also be of the bottom gate type, and a-Si may also be used for the active layer. The impurity doped in the source and drain regions 20s and 20d of the active layer 20 of the TFT can be any of n conductivity type and p conductivity type, but in this embodiment, n An n-oh type TFT with conductive impurities.

The active layer 20 of the TFT is covered with a gate insulating film 30 on which a gate electrode 32 made of a refractory metal material such as Cr or Mo and serving as a gate line is formed. And, after the gate electrode 32 is formed, the gate electrode 32 is used as a shield to form the source and drain regions 20s, 20d doped with the above impurity in the active layer 20, and form the source and drain regions 20s and 20d not doped with the impurity. channel region 20c. Next, an interlayer insulating film 34 is formed to cover all the TFTs 110. After forming a contact hole in the interlayer insulating film 34, an electrode material is formed, and the source electrode 40 is respectively connected to the above-mentioned p-Si electrode through the contact hole. source region 20s of the source layer 20, and connects the drain electrode 36 to the drain region 20d. Furthermore, in this embodiment, the drain electrode 36 also serves as a signal line for supplying data signals corresponding to display contents to each TFT 110. On the other hand, the source electrode 40 is connected to the first electrode 200 which is a pixel electrode as will be described later. In addition, for both the drain electrode 36 and the source electrode 40 , a highly conductive material such as Al or the like is used.

After the source electrode 40 and the drain electrode 36 are formed, the planarization insulating film 38 made of a resin material such as acrylic resin is formed to cover the entire substrate. Next, a contact hole is formed in the region where the source electrode 40 is formed in the planarizing insulating film 38 , and a connecting metal layer 42 is formed in the contact hole to connect the source electrode 40 and the metal layer 42 . When Al or the like is used for the source electrode 40 , by using a metal material such as Mo for the metal layer 42 , the connection between the source electrode 40 and the metal layer 42 becomes a good ohmic contact. Furthermore, the source electrode 40 may also be omitted. In this case, the metal layer 42 is in contact with the silicon active layer 20 of the TFT 110, and metal such as Mo can establish ohmic contact with such a semiconductor material.

After lamination and patterning of the metal layer 42 for connection, firstly, a reflective material layer with good reflective properties such as Al—Nd alloy and Al for the reflective layer is laminated on the entire surface of the substrate by vapor deposition, sputtering, or the like. The laminated reflective material layer is etched and removed from the vicinity of the source region of the TFT (the area where the metal layer 42 is formed), so as not to hinder the contact between the metal layer 42 and the pixel electrode 200 formed later and the TFT, and at the same time, it is etched and removed to The reflective layer 44 does not remain in the transmissive region 210 , but forms a rhombus pattern in the reflective region 220 of each pixel as shown in FIG. 3 . Furthermore, in order to prevent leakage current from being irradiated with light to the TFT (especially the channel region 20c), and in order to maximize the reflective region (that is, the display region), in this embodiment, as shown in FIG. 1 , The reflective layer 44 is also actively formed in the region above the channel of the TFT 110 .

When patterning the reflective layer 44, the metal layer 42 made of the aforementioned Mo or the like has a sufficient thickness (for example, 0.2 μm) and has sufficient resistance to an etching solution. Therefore, after the reflective layer 44 on the metal layer 42 is etched and removed, the metal layer 42 may not be completely removed and remain in the contact hole. In addition, in many cases, the source electrode 40 etc. is made of the same material (Al etc.) Corrosion caused disconnection, etc. However, in this embodiment, by providing the metal layer 42 , the patterning of the reflective layer 44 can be tolerated, and good electrical connection with the source electrode 40 can be maintained.

After the reflective layer 44 is patterned, the entire surface of the substrate including the reflective layer 44 is covered by laminating a transparent conductive layer by sputtering. Here, as described above, the surface of the reflective layer 44 made of Al or the like is covered with an insulating natural oxide film at this time, and the surface of high melting point metals such as Mo is not oxidized even if it is exposed to a sputtering environment. Therefore, the metal layer 42 exposed in the contact region can be in ohmic contact with the transparent conductive layer for pixel electrodes stacked on the metal layer 42 . Furthermore, after the film is formed, the transparent conductive layer is independent of each pixel, and shares the reflective area and the transmissive area in a pixel area, and is patterned into an elongated hexagonal shape as shown in FIG. 3 above, for example. Thus, the pixel electrode 200 is obtained. In addition, after the pixel electrode 200 is patterned, an alignment film 260 made of polyimide or the like is formed covering the entire surface of the substrate, thereby completing the first substrate side. Then, on the second substrate 300, the color filter layers of R, G, and B shown in FIG. 1 and FIG. The alignment film 260 formed by assembly, the second substrate 300 and the first substrate 100 are separated at a certain interval and bonded on the peripheral parts of the substrates, and liquid crystal is sealed between the substrates to obtain an LCD.

In addition, in the example of FIG. 1 and FIG. 2 , the common electrode 320 formed on the second substrate 300 side is formed on the upper layer of the gap adjustment part 340 , and the protrusion 510 is formed at a desired position of the common electrode 320 . In contrast, as shown in FIG. 4 , the common electrode 320 may also be formed under the gap adjustment portion 340 as shown in FIG. 340). When the gap adjustment part 340 is very thick, as shown in FIG. In the case between the electrode 320 and the pixel electrode 200, or in the case where the gap adjustment portion 340 is not too thick, the configuration shown in FIG. 4 can also be adopted.

Another example of the structure of each pixel of the transflective LCD of this embodiment will be described below. FIG. 7 shows the basic planar configuration of a transflective LCD of another example, and FIG. 8 shows the basic cross-sectional structure along line C-C' in FIG. 7 . In addition, the basic cross-sectional structure along the line D-D' in FIG. 7 is the same as the basic cross-sectional structure shown in FIG. 5 described above.

The difference from the structure shown in FIG. 3 above is that firstly, the shape of the pixel electrode 240 is a rectangle in the example in FIG. Protruding portions 510 t and 510 r in the shape of an X are formed at the positions of the hypotenuses of the quadrangle as the alignment control portion 500 . With the alignment control unit 500 of this kind, four regions with different alignment directions of liquid crystals are formed in the transmissive region 210 and the reflective region 220 with the protrusions 510t and 510r as boundaries, thereby further expanding the viewing angle.

In addition, at the boundary of the transmissive region 210 in one pixel region, as described above, the alignment control part 500 using the slope part 520 of the gap adjustment part 340 is formed on the side of the second substrate 300. The electrodeless portion (slit: window 530 s ) 530 extending in the horizontal scanning direction is formed on the pixel electrode 200 . Therefore, in the boundary region between the transmissive region 210 and the reflective region 220, on the side of the second electrode, the initial alignment of the liquid crystal is controlled to a direction perpendicular to the slope by the slope (slope 520) of the gap adjustment part 340, and at the same time On the first substrate side, the alignment of the liquid crystal is controlled to different orientation angles with the electrodeless portion 530s as a boundary by tilting the electrodeless portion 530s in a weak electric field as shown in FIG. 8 . Therefore, the alignment division of the liquid crystal near the boundary between the transmissive region 210 and the reflective electrode 220 can be performed more reliably.

As mentioned above, each pattern and the number of alignment divisions of the alignment control part 500 composed of the edge of the pixel electrode 200, the above-mentioned protrusion part 510, the electrodeless part 530s, etc. are also different from the form shown in FIG. 3 above, but in the figure In the form shown in 7, the alignment azimuth angle of the liquid crystal controlled by a certain alignment control unit 500 is also controlled by another alignment control unit 500 having a projection line intersecting the projection line of the alignment control unit 500 on the substrate plane. The angle difference of the alignment azimuth angles of the liquid crystals was less than 90 degrees at any intersection point. Therefore, generation of disclination lines at indeterminate positions within each divided alignment region can be reliably prevented. In addition, by adopting the pattern of the alignment control portion 500 shown in FIG. 3 and FIG. 7 , the maximum number of alignment divisions can be achieved with the minimum formation of the alignment control portion 500 and the alignment division can be performed reliably. In the vertical alignment type liquid crystal used in this embodiment, in order to display black in the voltage non-applied state (that is, the vertical alignment state), not only directly above the gap of the pixel electrode 200, but also in other alignment control parts 500 (protruding parts) 510, the inclined portion 520 and the slit 530s), even if a sufficient voltage is applied between the common electrode 320 and the pixel electrode 200, the alignment state of the liquid crystal will hardly change from the vertical alignment state without affecting show. Therefore, useless disposition of the alignment control unit 500 reduces the aperture ratio of the LCD. However, according to the design shown in Fig. 3 and Fig. 7 described above, the aperture ratio can be kept to a minimum, and the viewing angle can be enlarged and the display quality can be improved.

9 and 10 show other modification examples of the above-mentioned structure shown in FIG. 3, respectively.

First, in FIG. 9, all the pixel electrodes 250 are formed in the shape of arrow feathers, and the shape and structure of the reflective region 220 are the same as those in FIG. The drum shape or slightly hourglass shape, or the shape of the upper and lower sides of the M letter. Both sides of the pixel electrode 250 of the transparent region 210 where the projected line of the protrusion 510t intersects the projected line on the same plane and the projected line on the same plane are formed at an angle larger than 90 degrees.

(here 135 degrees) cross. As described above, since the liquid crystal molecules have no characteristic difference up and down in the major axis direction, the angle difference of the alignment azimuth angles of the liquid crystals in the intersecting region is still less than 90 degrees. In addition, the two sides of the lower part of the pixel electrode 250 extending from the intersecting position with the above-mentioned protrusion 510t to the lower ends of the two sides of the pixel electrode 250 extending along the vertical scanning direction respectively, and the sides of the pixel electrode 250 along the vertical scanning direction. The intersecting angle of the sides is less than 90 degrees, and in this region, the maximum difference in alignment azimuth angles of the liquid crystals is also less than 90 degrees (less than 45 degrees in the example of FIG. 9 ). Therefore, generation of disclination lines at indeterminate positions can also be prevented in the two alignment regions in the penetrating region 210 .

In FIG. 10, the shape of the pixel electrode 252 is an arrow-feather shape, and the shape (arrow-feather shape) and structure of the penetrating region 210 are the same as those in FIG. And the formation positions of the protrusions 510r for dividing the alignment of the liquid crystal in the region are different. That is, in the example of FIG. 10 , the reflective region 220 is also in the shape of an arrow-feather with a short length, and the boundary between the reflective region 220 and the transmissive region 210 is divided by the alignment division by the V-shaped inclined part 520 of the gap adjustment part 340, A protrusion 510r is formed on the second substrate side (on the gap adjusting portion) on a line along the vertical scanning direction connecting the V-shaped apex and the same V-shaped apex of the pixel electrode 252 in the reflective region 220, so that The protruding portion 510r is a boundary forming two left and right alignment regions in the reflection region 220 in the horizontal scanning direction. In this configuration, the alignment azimuth angle of the liquid crystal controlled by which alignment control unit 500 is different from that of the liquid crystal controlled by the other alignment control unit 500 having a projection line intersecting the projection line of the alignment control unit 500 toward the substrate plane. Since the angle difference of the alignment azimuth angles satisfies a relationship of less than 90 degrees, good alignment division can be performed.

Next, the driving voltage, transmittance and wavelength dependence of the vertical alignment type transflective LCD of this embodiment will be described.

Figure 11 shows the relationship between the applied voltage (V) applied to the liquid crystal and the transmittance (arbitrary unit), but the optical characteristics of the vertical alignment liquid crystal cell represented by (del-n)d/wl...(i), In other words, it is the relationship between the applied voltage and the transmittance when changing the structure of the liquid crystal cell. Among them, in FIG. 11, wl is 550 nm (green). In the above formula (i), (del-n) is birefringence (ie, refractive index anisotropy) (Δn) of the liquid crystal layer, d is the thickness of the liquid crystal layer (cell gap), and wl is the wavelength of incident light. In small-sized LCDs mounted on portable devices such as mobile phones, it is desired to further reduce power consumption and drive voltage, etc., and as can be seen from FIG. The applied voltage to realize the maximum penetration rate is about 3V. If the value is increased to 1.1 or 1.2, the driving voltage can be less than 3V. When using the same liquid crystal material and the same light source by adjusting the d value, it can also be driven at a very low voltage. The d value can be determined by the gap adjustment part 340, the color filter layer 330 or the flat The thickness of the insulating layer 38 is adjusted.

In addition, it can be seen from the fact that the formula (i) has the "wl" component that, in the LCD of this embodiment, the transmittance characteristic is wavelength-dependent. In Fig. 12, when the thickness (cell gap) d of the entire liquid crystal layer of each pixel of R, G, and B is set constant, the transmittance characteristics with respect to the applied voltage are different for R (630nm), G (550nm) , The difference between B (460nm) light. In contrast, FIG. 13 shows that the liquid crystal cell gap is adjusted by changing the thickness of the color filter layers 330r, 330g, and 330b (which can be adjusted by the thickness of the gap adjusting part 340) in each R, G, and B as shown in FIG. The relationship between LCD applied voltage and transmittance for the value of d. It can be seen from Fig. 13 that by setting the cell gap d to desired values in R, G, and B respectively, the transmittance characteristics of any light of R, G, and B to the corresponding applied voltage of each pixel can be uniform. same. Therefore, with this configuration, it can be seen that R, G, and B can be driven with display signals of the same amplitude by an applied voltage of less than 3 V as shown in FIG. 11 above.

14 and 15 show the applied voltage dependence of chromaticity (X-Y coordinates of CIE). Among them, Fig. 14 is as shown in Fig. 12, when the liquid crystal cell gap is set to be the same in R, G, and B in the LCD, when the voltage applied to the liquid crystal is set to 1.5V, 2.0V, 2.3V, 2.6V, and 3.0V The change of the chromaticity, Figure 15 is shown in Figure 13, in the LCD in which the gap of the liquid crystal cell is adjusted separately for R, G, and B, and the transmittance of the applied voltage changes, the chromaticity dependence of the applied voltage will be applied to the liquid crystal Changes in chromaticity when the voltage of the same is set to 1.5V, 2.0V, 2.3V, 2.6V, and 3.0V. From the comparison of Figure 14 and Figure 15, it can be seen that by adjusting the liquid crystal cell gaps in R, G, and B respectively, the applied voltage dependence of changing the chromaticity can be improved, that is, the chromaticity deviation when the voltage is applied, and in various voltage ranges LCDs with less chromaticity deviation can be realized when driving.

second embodiment

Next, a second embodiment of the present invention, that is, an aspect of improving display quality in color display, will be described. Hereinafter, the color display of a vertical alignment type liquid crystal display device will be described as an example.

The vertical alignment type liquid crystal display device has the characteristics of wide viewing angle and high contrast ratio, and has the advantage of not requiring rubbing treatment of the alignment film.

In the related vertical alignment liquid crystal display device, since the liquid crystal has the characteristic of negative dielectric anisotropy, the liquid crystal molecules constituting the liquid crystal have the characteristic of orienting in a direction perpendicular to the direction of the electric field. This liquid crystal display device uses a vertical alignment film as the alignment film to control the initial alignment of liquid crystals, and uses organic materials such as polyimide and polyamide as the material of the vertical alignment film. In a vertical alignment type liquid crystal display device, when no electric field is applied to the liquid crystal, the liquid crystal molecules are controlled by the vertical alignment film to face the normal direction of the substrate formed by the vertical alignment film. When a voltage is applied between the pixel electrode and the common electrode to generate an electric field in the normal direction of the substrate, the liquid crystal molecules in the area controlled by these electric fields will fall in a direction perpendicular to the electric field.

As a result, the phase of incident light transmitted to the liquid crystal changes. When the distance (gap) between the substrates sandwiching the liquid crystal is d, the refractive index of the liquid crystal is Δn, and the wavelength of light is λ, the phase change of incident light transmitted to the liquid crystal is Δnd/λ. Then, by passing the light passing through the liquid crystal through the polarizing plate attached to the aforementioned substrate, the transmittance of the incident light can be changed, and a desired liquid crystal display can be obtained. In this case, for example, the aforementioned polarizing plate is set so as to perform black display when no voltage is applied, and to maximize the transmittance of incident light at a certain voltage (white voltage White) when voltage is applied.

Regarding such a vertical alignment type liquid crystal display device, a full-color vertical alignment type liquid crystal display device also having pixels of RGB3 primary colors has recently been developed.

However, in a full-color vertical alignment type liquid crystal display device, since the wavelength λ of the light passing through the color filter layer of the color filter layer of each pixel of RGB3 primary colors is different according to each pixel, it is impossible to adjust the transmittance with a certain voltage. is the maximum. That is, as shown in FIG. 17C , V-T characteristics (characteristics of transmittance to liquid crystal applied voltage) are different for each RGB pixel. In the V-T characteristic, the transmittance T increases with the increase of the voltage V applied to the liquid crystal, and if it exceeds the maximum value, it turns to decrease. Generally, in RGB, white voltage Vwhite is set as liquid crystal application voltage V in accordance with B (blue) whose transmittance T becomes high at the lowest voltage.

When the white voltage Vwhite is applied, since the transmittance of G (green) and R (red) does not reach 100%, there is a problem that white is perceived as bluish. Therefore, increasing the voltage applied to the liquid crystal (driving voltage) of the R pixel can improve such a problem of color shift, but causes the problem of increased power consumption of the liquid crystal display device.

16 is a cross-sectional view of a vertical alignment liquid crystal display device according to a second embodiment of the present invention. Among them, the same symbols are assigned to the same configurations as those of the aforementioned first embodiment (particularly FIG. 1 ), and description thereof will be omitted. The second embodiment is the same as the aforementioned first embodiment, in that each corresponding pixel used as RGB3 primary color display has a transmissive area and a reflective area, and the semi-transmissive area that is convenient to observe no matter whether the surrounding environment is bright or dark A type LCD is used as an example for description, but it is also applicable to a transmissive type LCD or a reflective type LCD having pixels of RGB3 primary colors.

On the first glass substrate 100, TFTs 20 for liquid crystal driving are respectively formed in each pixel of RGB3 primary colors, and an interlayer insulating film covering these TFTs 20 for liquid crystal driving is formed (it is better to form a planarizing insulating film thereon). )34. A pixel electrode 200 is formed in each pixel region on the interlayer insulating film 34 . In the transmissive area, the transparent electrode 210 made of ITO forms the pixel electrode 200 , and in the reflective area, the reflective electrode 220 made of a material with good reflective properties such as aluminum forms the pixel electrode 200 .

In the B pixel, the reflective electrode 220 (b) is connected to the source or drain of the liquid crystal driving TFT 20 through the contact hole formed in the interlayer insulating film 34, and the reflective electrode 220 is in contact with the transparent electrode 210 and is electrically connected. . Similarly, in the G pixel and the R pixel, the reflective electrode 220 is also connected to the source or drain of the liquid crystal driving TFT 20 through the contact hole formed in the interlayer insulating film 34, and the reflective electrode 220 is in contact with the transparent electrode 210 and electrical connection. When it is difficult to directly contact the reflective electrode 220 with the transparent electrode 210, as described above with respect to FIG. A transparent electrode 210 made of a transparent conductive metal oxide is formed, and the transparent electrode 210 is connected to the TFT 20 through a contact hole.

A first vertical alignment film 262 made of organic materials such as polyimide and polyamide is formed to cover the transparent electrode 210 and the reflective electrode 220 of each pixel.

In addition, the second glass substrate 300 opposite to the aforementioned first glass substrate 100 is arranged parallel to the substrate 100 . On the surface opposite to the first glass substrate 100 of the second glass substrate 300, corresponding to each pixel of RGB3 primary colors, the light source from the second substrate 300 side or from the first substrate 100 side as shown in FIG. , or the incident light from the light source of the external light from the second substrate 300 side that enters the liquid crystal layer 400 and enters the second glass substrate 200 is filtered. In addition, a B-color filter layer 332b that transmits blue light, a G-color filter layer 332g that transmits green light, and an R-color filter layer 332r that transmits red light are formed.

In addition, in each reflective region of each pixel, a protruding portion 340b made of optically sensitive resin is formed in a region corresponding to the reflective region of the B color filter layer 332b, and a protrusion 340b formed of optically sensitive resin is formed in a region corresponding to the reflective region of the G color filter layer 332g. There is a protruding portion 340g formed of an optically sensitive resin, and a protruding portion 340r formed of an optically sensitive resin is formed in a region corresponding to the reflective region of the R color filter layer 332r. These protrusions 340 (340b, 340g, 340r) are gap adjustment layers (protrusions for gap adjustment) for adjusting the required gap in the reflective region and the transmissive region, which were also described in the first embodiment. The gap adjustment layer 340 is selectively arranged in the reflective area, so that the distance (gap) between the first glass substrate 100 and the second glass substrate 300 in the reflective area is smaller than that in the transparent area, so that the reflective characteristics are good (in the reflective area). display properties). In addition, in the present embodiment, the thickness of the protruding portion 340 is made common to the R, G, and B pixels.

Furthermore, the B color filter layer 332b, the G color filter layer 332g, and the R color filter layer 332r respectively provided with the protruding portion 340 are covered to form a transparent common electrode 320 made of ITO, and then the common electrode 320 is covered and formed. A second vertical alignment film 264 made of organic materials such as polyimide and polyamide is formed. Then, liquid crystal 400 having negative dielectric anisotropy is sealed in the space between the first glass substrate 100 and the second glass substrate 300 .

A λ/4 plate 111 as a retardation plate and a polarizing plate 112 are attached to the back surface (light emitting surface) of the first glass substrate 100 . Similarly, a λ/4 plate 111 and a polarizing plate 112 as a retardation plate are attached to the back surface (light exit surface) of the second glass substrate 200 . Therefore, it is set so that according to the voltage setting of the pixel electrode and the common electrode 214, when no voltage is applied to the liquid crystal 400, the incident light incident on the liquid crystal layer 400 will not pass through the second glass substrate 300 side to the outside. In this way, black display is realized; and when a voltage is applied to the liquid crystal layer 400, the light emitted from the side of the second glass substrate 300 corresponding to the voltage will increase, that is, the transmittance of the incident light on the liquid crystal layer will increase.

In the second embodiment of the present invention, the feature is that the thicknesses of the color filter layers 332b, 332g, and 332r of B, G, and R are set. When the thickness of the B-color filter layer 332b is D-blue, the thickness of the G-color filter layer 332g is D-green, and the thickness of the R-color filter layer 332r is D-red, D-blue≥D- The relational expression of green>D-red. In the transmissive area of each pixel of RGB, the gap (thickness of the liquid crystal sandwiched between the two substrates) has an inverse relationship with the size of each color filter layer. That is, when the gap of the transparent area of the B pixel is G-blue (T), the gap of the transparent area of the G pixel is G-green (T), and the gap of the transparent area of the R pixel is G-red (T), The relationship is G-red(T)≥G-green(T)>G-blue(T). In this way, the thicknesses of the B-color filter layer 201, the G-color filter layer 202, and the R-color filter layer 203 are set to be different, so that the gaps of the pixels (also called liquid crystal cell gaps) are different, and RGB The V-T characteristics of each pixel are uniformed.

Next, V-T characteristics of each pixel of RGB will be described based on the experimental results shown in FIG. 2 . In FIGS. 17A to 17C , the horizontal axis represents the voltage applied to the liquid crystal 300 , and the vertical axis represents the transmittance of incident light.

First, as shown in FIG. 17C, in the case of D-blue=D-green=D-red (the same thickness of all color filter layers), the V-T characteristics of each RGB are greatly different. As shown in FIG. 17A, if set Assuming that D-blue>D-green>D-red, then the V-T characteristics of B and R pixels are close to the V-T characteristics of G pixels. And, by setting the thicknesses of the B color filter layer 332b, the G color filter layer 332g, and the R color filter layer 332r, the respective gaps of RGB are set to G-red(T)=4.8 μm, G-green (T) = 4.0 μm, G-blue (T) = 3.3 μm, so that the V-T characteristics of RGB can be made approximately the same. Therefore, by selecting an appropriate white voltage White (for example, a voltage v that maximizes the transmittance), a display without color shift can be obtained under low-voltage driving.

In addition, as shown in Figure 17B, if D-blue=D-green>D-red is set, the V-T characteristics of B and G pixels are the same as those in Figure 17C, while the V-T characteristics of R pixels are close to the V-T characteristics of G pixels. In this way, compared with the V-T characteristic of FIG. 17C , since the R pixel can obtain high transmittance with a lower voltage V, the problem of color shift can be improved.

On the other hand, in the reflective area, the gap adjustment layers (protrusions) 340r, 340g, and 340b of the RGB pixels are provided, and the color filter layers 332b, 332g, and 332r of the aforementioned B, G, and R are simultaneously present in the transmissive area. area and reflection area. Therefore, by setting the thicknesses of these color filter layers 332b, 332g, and 332r respectively as described above, the relationship between the size of the gap in the reflective region and the relationship in the transmissive region will be the same. That is, if the B pixel gap in the reflection area is G-blue (R), the G pixel gap is G-green (R), and the R pixel gap is G-red (R), the protrusions 211, 212, 213 If the heights are the same, the relationship is G-red(R)>G-green(R)≥G-blue(R). Therefore, according to the second embodiment, the V-R characteristic (reflection ratio versus liquid crystal applied voltage characteristic) of each pixel of RGB is also more uniform, so the display without color shift under low voltage driving can also be obtained.

Next, the method for forming the color filter layers 332r, 332g, and 332b of the aforementioned R, G, and B colors will be described. For each color filter layer, basically, the optically active resin containing the color pigment is spin-coated on the second glass substrate 300, and the pattern is left in a predetermined area through exposure and development. However, in the second embodiment, since the thicknesses of the color filter layers are not exactly the same, if the thicker color filter layer, such as the B-color filter layer 332b, is formed first, the unevenness on the surface of the second glass substrate 300 will become larger. This makes it difficult to form other color filter layers, such as the R color filter layer 332r.

Here, the thinnest R color filter layer 332r is formed first, and then the G color filter layer 332g and the B color filter layer 332b are formed in sequence. This manufacturing step is easier to implement and is ideal. In the case where the B color filter layer 332b and the G color filter layer 332g have the same thickness, the two color filter layers with the same thickness can be formed in any order.

third embodiment

Next, a description will be given of a third embodiment of the present invention with reference to the drawings. FIG. 18 is a schematic cross-sectional structural view of a vertical alignment type liquid crystal display device according to a third embodiment. Components common to those of the aforementioned second embodiment are given the same reference numerals, and description thereof will be omitted.

In the third embodiment, in each pixel of R, G, and B, in order to set each gap G to an optimum different thickness, except for the color filter layers of R, G, and B formed on the second glass substrate 300 side, 330r, 330g, 330b, and the protruding portion 340 (340r, 340g, 340b) for adjusting the gap difference between the transmissive area and the reflective area, it also has an adjustment layer ( interstitial layer) 350. Specifically, in the B and G pixel areas where the liquid crystal cell gap G is required to be smaller than the R pixel area, each optically sensitive resin layer 350b, 350g is selectively formed on the B color filter layer 330b, and the G color filter layer 330b. The color filter layer 330g is used as the adjustment layer 350 . Here, let the thickness of the optically sensitive resin 350b on the B color filter layer 330b be t1, and the thickness of the optically sensitive resin 350g on the G color filter layer 330g be t2. In addition, if the gap (thickness of the liquid crystal between the two substrates) of the transmissive region of the B pixel is G-blue(T), then t1≥t2 is set. If the gap of the penetrating region of the G pixel is G-green(T), and the gap of the penetrating region of the R pixel is G-red(T), then the following conditions are satisfied:

The relationship of G-red(T)>G-green(T)≥G-blue(T).

In addition, in the third embodiment, as shown in FIG. 18 , when the thicknesses of the color filter layers 330r, 330g, and 330b are respectively the same, and the thicknesses of the protruding portions 340r, 340g, and 340b are also respectively the same, at t1 =t2, the liquid crystal cell gap satisfies G-green=G-blue.

In this way, the optically sensitive resin layer 350 is selectively formed in the necessary color area, and the gap between each pixel (also called the liquid crystal cell gap) is set to different optimum values according to R, G, and B respectively, so that the color of RGB can be adjusted. The V-T characteristics of each pixel are uniform.

Next, based on the experimental results shown in FIGS. 19A to 19C , the V-T characteristics of each pixel for RGB will be described. In FIGS. 19A to 19C , the horizontal axis is the voltage applied to the liquid crystal 400 , and the vertical axis is the transmittance of incident light.

First, as shown in FIG. 19C, in the case of G-red(T)=G-green(T)=G-blue(T) (the case where no optically sensitive resin layers 250g and 250b are provided), each RGB The V-T characteristics of the V-T are quite different. In contrast, as shown in FIG. 19A, if the setting is G-red(T)>G-green(T)>G-blue(T), the V-T characteristics of B and R pixels are close to those of G pixels (without correction In this case, the respective characteristics of R, G, and B are shown in Fig. 19A, respectively). More specifically, by setting the respective gaps of RGB to G-red=4.8 μm, G-green=4.0 μm, and G-blue=3.3 μm, the V-T characteristics of RGB can be made substantially the same. In this way, by selecting an appropriate white voltage Vwhite (for example, the voltage V at which the transmittance becomes the maximum), a display without color shift can be obtained under low-voltage driving.

In addition, as shown in Figure 19B, if G-red(T)>G-green(T)=G-blue(T) is set, the V-T characteristics of B and G pixels are the same as those in Figure 19C, while the R pixel's The V-T characteristic is close to that of the G pixel. In this way, in the R pixel, since a high transmittance can be obtained at a lower voltage V, the problem of color shift can be improved compared with the V-T characteristic of FIG. 19C.

On the other hand, in the reflective area, each pixel of RGB is provided with a protruding portion 340. Since the thickness of the protruding portion 340 is set to be equal according to R, G, and B, the relationship between the size of the gap in the reflective area is also related to the transmission. The same relationship as the preceding relationship for the region. That is, if the gap of the B pixel in the reflective area is G-blue (R), the gap of the G pixel is G-green (R), and the gap of the R pixel is G-red (R), it becomes: G-red ( R)>G-green(R)≥G-blue(R) relationship.

Therefore, according to the embodiment of the present invention, since the V-R characteristic (reflectance versus liquid crystal applied voltage characteristic) of each RGB pixel is more uniform, a display without color shift can also be obtained under low voltage driving.

Claims (18)

1. A vertical alignment type liquid crystal display device has R, G and B pixels for displaying red, green and blue primary colors, and the display device has: a first substrate with a pixel electrode formed on each of the pixels; A second substrate disposed opposite to the first substrate and having a common electrode; A liquid crystal having a negative dielectric anisotropy sealed between the first substrate and the second substrate; On the second substrate, an R color filter layer, a G color filter layer, and a B color filter layer are arranged corresponding to the R, G, and B pixels; a first vertical alignment film formed to cover the pixel electrodes; and A second vertical alignment film formed on the liquid crystal side relative to the common electrode and the R, G, and B color filter layers; in, A transparent electrode is used in the penetrating region in the pixel of the formation region of the pixel electrode, and a reflective electrode or a reflective layer is used in the reflective region in the pixel of the formation region of the pixel electrode; Protrusions for gap adjustment are formed on the second substrate in each reflective region in the pixel; The common electrode is formed to cover the gap adjustment protrusion; An alignment control portion for controlling the alignment direction of the liquid crystal is formed on the second substrate on which the gap adjustment protrusion is formed; If the thicknesses of the R-color filter layer, G-color filter layer and B-color filter layer are D-red, D-green, and D-blue respectively, D-blue≥D-green>D-red . 2. The vertical alignment type liquid crystal display device according to claim 1, wherein the pixel electrode is a transparent electrode. 3. The vertical alignment liquid crystal display device according to claim 1, wherein the pixel electrode is a reflective electrode. 4. The vertical alignment type liquid crystal display device as claimed in claim 1, wherein said R, G, B color filter layers use photosensitive resin. 5 . The vertical alignment type liquid crystal display device according to claim 1 , wherein the side surface of the gap adjusting protrusion has a forward tapered shape whose width increases toward the formation substrate of the gap adjusting protrusion. 6 . 6. A method for manufacturing a vertical alignment type liquid crystal display device, the vertical alignment type liquid crystal display device is provided with R, G, and B pixels for displaying the three primary colors of red, green, and blue, and has: a first substrate with a pixel electrode formed on each of the pixels; A second substrate disposed opposite to the first substrate and having a common electrode; A liquid crystal having a negative dielectric anisotropy sealed between the first substrate and the second substrate; On the second substrate, an R color filter layer, a G color filter layer, and a B color filter layer are arranged corresponding to the R, G, and B pixels; a first vertical alignment film formed to cover the pixel electrodes; and A second vertical alignment film formed on the liquid crystal side relative to the common electrode and the R, G, and B color filter layers; in, A transparent electrode is used in the penetrating region in the pixel of the formation region of the pixel electrode, and a reflective electrode or a reflective layer is used in the reflective region in the pixel of the formation region of the pixel electrode; Protrusions for gap adjustment are formed on the second substrate at least in each reflective region in the pixel; The common electrode is formed to cover the gap adjustment protrusion; An alignment control portion for controlling the alignment direction of the liquid crystal is formed on the second substrate on which the gap adjustment protrusion is formed; And if the thicknesses of the R-color filter layer, G-color filter layer and B-color filter layer are respectively D-red, D-green, and D-blue, D-blue≥D-green>D- red; In the manufacturing method of the vertical alignment liquid crystal display device, among the R, G, and B color filter layers, the thinnest material for the R color filter layer is prior to the B color filter layer and the material for the B color filter layer. The G color filter layer is formed on the side of the second substrate; Afterwards, any one of the B-color filter layer material or the G-color filter layer material is formed on the side of the second substrate. 7. the manufacture method of vertical alignment type liquid crystal display device as claimed in claim 6, wherein the filter material that is used for described R, G, B color filter layer is photosensitive resin, is coated on the substrate corresponding After the filter material is exposed and developed, it is patterned into the desired shape. 8. A method for manufacturing a vertical alignment type liquid crystal display device, the vertical alignment type liquid crystal display device is provided with R, G, and B pixels for displaying the three primary colors of red, green, and blue, and has: a first substrate with a pixel electrode formed on each of the pixels; A second substrate disposed opposite to the first substrate and having a common electrode; A liquid crystal having a negative dielectric anisotropy sealed between the first substrate and the second substrate; On the second substrate, an R color filter layer, a G color filter layer, and a B color filter layer are arranged corresponding to the R, G, and B pixels; a first vertical alignment film formed to cover the pixel electrodes; and A second vertical alignment film formed on the liquid crystal side relative to the common electrode and the R, G, and B color filter layers; in, A transparent electrode is used in the penetrating region in the pixel of the formation region of the pixel electrode, and a reflective electrode or a reflective layer is used in the reflective region in the pixel of the formation region of the pixel electrode; Protrusions for gap adjustment are formed on the second substrate at least in each reflective region in the pixel; The common electrode is formed to cover the gap adjustment protrusion; On the second substrate on which the protrusion for gap adjustment is formed, an alignment control portion for controlling the alignment direction of the liquid crystal is formed; and If the thicknesses of the R-color filter layer, G-color filter layer and B-color filter layer are D-red, D-green, and D-blue respectively, D-blue≥D-green>D-red , In the method of manufacturing the vertical alignment type liquid crystal display device, coating a first filter material containing an R-color pigment on the surface of the second substrate, and patterning the first filter material to form the R-color filter layer; Afterwards, coating a second filter material containing a G-color pigment on the surface of the second substrate, and patterning the second filter material to form the G-color filter layer; Next, coating a third filter material containing a B-color pigment on the surface of the second substrate, and patterning the third filter material to form the B-color filter layer. 9. The method of manufacturing a vertical alignment liquid crystal display device according to claim 8, wherein the first to third filter materials are photosensitive resins. 10. The method for manufacturing a vertical alignment liquid crystal display device according to claim 9, wherein the photosensitive resin coated on the forming surface of the second substrate forms the Desired patterned color filter layer. 11. A vertical alignment liquid crystal display device, equipped with R, G, and B pixels for displaying the three primary colors of red, green, and blue, and the display device has: a first substrate with a pixel electrode formed on each of the pixels; A second substrate disposed opposite to the first substrate and having a common electrode; A liquid crystal having a negative dielectric anisotropy sealed between the first substrate and the second substrate; On the second substrate, an R color filter layer, a G color filter layer, and a B color filter layer are arranged corresponding to the R, G, and B pixels; a gap layer formed only on the G color filter layer and the B color filter layer; a first vertical alignment film formed to cover the pixel electrodes; and A second vertical alignment film is formed on the liquid crystal side relative to the common electrode, the R, G, B color filter layers and the gap layer. 12. The vertical alignment liquid crystal display device according to claim 11, wherein the gap layer is made of a photosensitive resin material. 13. The vertical alignment type liquid crystal display device as claimed in claim 11, wherein the gap layer formed on the B color filter layer is larger than the gap layer formed on the G color filter layer The layers are still thick. 14. The vertical alignment type liquid crystal display device according to claim 11, wherein the pixel electrode is a transparent electrode. 15. The vertical alignment liquid crystal display device of claim 11, wherein the pixel electrode is a reflective electrode. 16. The vertical alignment liquid crystal display device according to claim 11, wherein in the transmissive area in the pixel, the pixel electrode uses a transparent electrode, and in the reflective area in the pixel, the pixel electrode uses a reflective electrode. electrode or reflective layer. 17. The vertical alignment type liquid crystal display device as claimed in claim 16, wherein On the R color filter layer, the G color filter layer, and the B color filter layer, at least in each reflection area, a gap adjustment protrusion formed of a photosensitive resin is formed; The common electrode is formed to cover the gap adjusting protrusion. 18. The vertical alignment liquid crystal display device according to claim 11, wherein said R, G, B color filter layers use photosensitive resin.

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