JP2003161943A - Reflective liquid crystal display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reflective liquid crystal display element excellent in contrast and color compensation. <P>SOLUTION: In the reflective liquid crystal display element provided with an optical retardation plate 12 and a polarizing plate 13 disposed in this order on an outer surface of a front surface side substrate 2, the element is characterized by having 65-75 nm optical retardation value of the optical retardation plate 12 and making parameters α, β and γ satisfy inequalities 10°≤α≤20°, 115°≤β≤135° and 80°≤γ≤90°, representing angles, measured clockwise seen from the front surface side of the liquid crystal display element, which a rubbing direction of an alignment layer 7 of the front surface side substrate 2, taken as a reference direction, forms with an absorption axis of the polarizing plate 13, with a slow axis of the optical retardation plate 12 and with a rubbing direction an alignment layer 8 of the rear surface side substrate 3 as α, β and γrespectively. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflective liquid crystal display device using a nematic liquid crystal, and more particularly to a reflective liquid crystal display device using a retardation plate for color compensation, viewing angle expansion and the like. .

[0002]

2. Description of the Related Art Conventionally, liquid crystal display devices using nematic liquid crystals have been popularly used for large panels such as personal computer displays and televisions, but in recent years, small electronic devices such as mobile phones, personal digital assistants, Demand for small and medium-sized panels is increasing as the market for in-vehicle TVs, car navigation systems, etc. expands. Since these small electronic devices are often used outdoors and need to be driven by a battery, it has been required to reduce power consumption as much as possible. Therefore, also for the liquid crystal display element, the development of a technique for reducing the power consumption at the same time as having high definition is being advanced. In order to reduce the power consumption of the liquid crystal display element, in order to reduce the power consumption by the backlight, a reflection type lighting system in which light incident from the front side of the liquid crystal display element is reflected and used is effective. In the present specification, the side closer to the viewer of the liquid crystal display element is the front side, and the far side is the back side.

FIG. 6 shows a conventional reflective liquid crystal display element 10.
1 is a schematic view of a sectional structure of FIG. The liquid crystal display element 101 is
An electrode 105 and an alignment film 107 are provided on the inner surface of the front substrate 102, and the reflective layer 1 is provided on the inner surface of the rear substrate 103.
04, the electrode 106, and the alignment film 108. The front substrate 102 and the rear substrate 103 are opposed to each other such that the electrodes 105 and 106 face each other, and spacers 109 are scattered in order to maintain a constant distance (cell gap) therebetween. , 103 are surrounded by a sealing material 110. Furthermore, both substrates 1
A nematic liquid crystal material 111 is enclosed in a space formed by 02 and 103 and the sealing material 110. In addition, a quarter-wave retardation plate 112a, a half-wave retardation plate 112b, and a polarizing plate 113 are provided in this order on the outer surface of the front substrate 102.

In this way, the reflective layer 104 is formed on the rear substrate 1
03, and only one polarizing plate 113 is used on the outer surface of the front substrate 102 to form an SPD (Single).
By adopting the Polarizer Display mode, it is possible to eliminate parallax due to the rear substrate 103.

The retardation plate has a function of changing the polarization state of light (the shape of polarization of the polarization plane of light). In a liquid crystal display element, circularly polarized light is changed to linearly polarized light and linearly polarized light is changed to circularly polarized light. It is used for optical compensation such as color compensation and widening of viewing angle. In this case, wavelength 400 to 7
It has been considered desirable to convert linearly polarized light into circularly polarized light and circularly polarized light into linearly polarized light in the visible light region of 70 nm.

If a quarter-wave retarder is used, linearly polarized light and circularly polarized light can be converted at that wavelength. However, since the conventional retardation film could not be converted over the entire wavelength in the visible light region, as shown in FIG.
A structure in which two retardation plates of the wavelength retardation plate 112b are attached so that their slow axes intersect at an appropriate angle has been used.

[0007]

However, although the conventional liquid crystal display element 101 uses the quarter-wave retardation plate 112a and the half-wave retardation plate 112b, the contrast and color compensation are sufficient. Turned out not to be. Particularly, in the case of black display, a bluish black color is generated, and a higher quality image is displayed. Therefore, a purer black (achromatic black) display in which other colors are not mixed is required. . Further, since two retardation plates are used, the number of parts is increased, leading to an increase in the number of processes and an increase in cost.

An object of the present invention is to solve the above problems and to provide a reflective liquid crystal display device excellent in contrast and color compensation.

[0009]

In order to achieve the above-mentioned object, a reflective liquid crystal display device of the present invention has a front side substrate and a back side substrate having electrodes and an alignment film provided on the inner surface, A negative liquid crystal display device in which a nematic liquid crystal is sealed between a front substrate and the rear substrate, and a retardation plate and a polarizing plate are provided in this order on the outer surface of the front substrate, wherein the rear substrate Has a reflective layer that reflects light incident from the front side, the retardation value of the retardation plate is 65 to 75 nm, and the front side of the liquid crystal display device is based on the rubbing direction of the alignment film of the front side substrate. The angle formed by the absorption axis of the polarizing plate is α, the angle formed by the slow axis of the retardation plate is β, and the angle formed by the rubbing direction of the alignment film of the back side substrate in the clockwise direction when viewed from the side. Is defined as γ,
α, β and γ are 10 ° ≦ α ≦ 20 °, 115 ° ≦ β
It is characterized by satisfying ≦ 135 ° and 80 ° ≦ γ ≦ 90 °.

By adopting such a structure, the liquid crystal display element of the present invention can display a more achromatic black color and can further increase the contrast.
We were able to display high quality images. Moreover, since the liquid crystal display element can be configured by one retardation plate, the number of parts can be reduced, and the number of steps and the cost can be reduced.

Particularly, in the liquid crystal display element of the present invention, the retardation value in the nematic liquid crystal is 234 to 273 nm.
And the cell gap between the front substrate and the rear substrate is more preferably 3.0 to 3.5 μm.

Further, it is preferable that the reflective layer also serves as an electrode provided on the inner surface of the rear substrate.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic view of a sectional structure of a negative type reflective liquid crystal display element 1 embodying the present invention. The front substrate 2 of the liquid crystal display element 1 has an electrode 5 and an alignment film 7 on its inner surface, and the back substrate 3 of the liquid crystal display element 1 has a reflective layer 4, an electrode 6 and an alignment film 8 on its inner surface. is doing.
Then, the front side substrate 2 and the back side substrate 3 are opposed to each other such that the electrodes 5 and 6 face each other, and spacers 9 for keeping a cell gap at a constant distance are scattered between the both substrates 2, 3 and 2. The periphery of is surrounded by a seal material 10. Further, a nematic liquid crystal material 11 is enclosed in a space formed by both the substrates 2 and 3 and the sealing material 10.
In addition, the retardation plate 12 and the polarizing plate 13 are provided in this order on the outer surface of the front substrate 2.

In the liquid crystal display element 1, the retardation value generated by the nematic liquid crystal material 11 is 234 to 273.
It is preferably nm. The cell gap between the front substrate 2 and the rear substrate 3 is preferably in the range of 3.0 to 3.5 μm, more preferably 3.15 to.
It is in the range of 3.35 μm. The retardation value of the liquid crystal material is Δ
It can be obtained by n · d (birefringence Δn × cell gap d). However, in the currently used liquid crystal material system, changing the birefringence (Δn) also changes other physical properties. It is preferable to adjust and control the cell gap rather than adjusting Δn).

In the liquid crystal display element 1 of FIG. 1, the reflective layer 4
The component positioned on the front side of the structure needs to be transparent at least in the visible light region. Therefore, a transparent glass substrate or a synthetic resin substrate is usually used for the front substrate 2, and a transparent conductive film such as ITO is used for the electrodes 5 and 6. Note that color display can be performed by disposing a color filter on the front side of the reflective layer 4.

The reflective layer 4 is made of a material having a function of reflecting light incident from the front side, and a metal material such as aluminum (Al) or silver (Ag) can be used. When the reflective layer 4 is formed of a conductive material, it is effective to use the electrode 6 of the rear substrate also as the component, the number of steps and the cost can be reduced. The reflective layer 4 may have minute irregularities formed on its surface in order to efficiently scatter incident light. Further, a flattening layer having a flat surface may be formed so as to cover the reflective layer 4.

The alignment films 7 and 8 have been rubbed, and the nematic liquid crystal material 11 near the substrate is aligned along the rubbing direction of the alignment films 7 and 8. Therefore, the twist angle of the nematic liquid crystal material 11 is determined by the rubbing direction of the alignment film 7 and the rubbing direction of the alignment film 8.

The phase difference plate 12 has a phase difference value of 65 to 7
The range is 5 nm, and more preferably the range is 68 to 72 nm. The retardation value was measured by the Senarmont method at room temperature. As the retardation plate 12, a polyether sulfone type,
Polycarbonate type, polymethylmethacrylate type,
A transparent polymer material such as polyvinyl alcohol-based, norbornene-based, polypropylene-based or the like can be used.
In particular, a retardation plate using a polymer material of polycarbonate type or norbornene type (for example, Arton material manufactured by JSR Co., Ltd.) is preferable because the retardation value hardly changes with temperature and wavelength.

The retardation plate is usually obtained by mechanically stretching a polymer material, and the slow axis of the retardation plate coincides with the stretching direction. The retardation plate 12 is arranged outside the front substrate 2 so that the angle between the slow axis and the rubbing direction of the alignment film 7 of the front substrate 2 satisfies the condition described later.

The polarizing plate 13 has its absorption axis and the front substrate 2
The alignment film 7 is disposed on the retardation plate 12, that is, on the front surface side of the liquid crystal display element so that the angle with the rubbing direction of the alignment film 7 satisfies the condition described later.

Next, the arrangement relationship between the rubbing directions of the alignment films 7 and 8, the slow axis of the retardation plate 12 and the absorption axis of the polarizing plate 13 will be described with reference to FIG. FIG. 2 shows the absorption axis 15 of the polarizing plate 13 and the slow axis of the retardation plate 12 with reference to the rubbing direction 14 of the alignment film 7 of the front substrate 2 when the liquid crystal display element 1 is viewed from the front side. 16 and the alignment film 8 on the rear substrate 3
It is a figure showing the arrangement relation of the rubbing direction 17 of FIG.

As shown in FIG. 2, in the present specification, the rubbing direction 14 of the alignment film 7 of the front substrate 2 is used as a reference (0 °), and the rubbing direction 14 of the alignment film 7 of the front substrate 2 is set.
The clockwise angle between the absorption axis 15 of the polarizing plate 13 and α
And β is the clockwise angle between the rubbing direction 14 and the slow axis 16 of the retardation plate 12, and is the clockwise angle between the rubbing direction 14 and the rubbing direction 17 of the alignment film 8 of the rear substrate 3. The angle is γ.

The angle α is an intersection angle between the rubbing direction 14 of the alignment film 7 and the absorption axis 15 of the polarizing plate 13, and 10 ° ≦ α ≦
The range of 20 ° is preferable, and most preferably 13 ° ≦ α ≦
It is 17 °. The angle β is determined by the rubbing direction 14 of the alignment film 7.
And the slow axis 16 of the retardation plate 12 intersects at 115 °
The range of ≦ β ≦ 135 ° is preferable, and most preferably 12
3 ° ≦ β ≦ 127 °. The angle γ is an intersection angle between the rubbing direction 14 of the alignment film 7 and the rubbing direction 17 of the alignment film 8, and is preferably in the range of 80 ° ≦ γ ≦ 90 °, and most preferably 84 ° ≦ γ ≦ 86 °.

Under these conditions, the liquid crystal display element 1 of the present invention can display a more achromatic black color and can further increase the contrast, so that a high quality display can be performed. did it. Moreover, since the liquid crystal display element can be formed by one retardation plate 12, the number of parts can be reduced, and the number of steps and the cost can be reduced.

Next, the color liquid crystal display element 31 embodying the present invention will be described with reference to FIG. FIG. 3 is a schematic diagram of a cross-sectional structure of the liquid crystal display element 31, in which a color filter 32 and a flattening layer 33 are added between the reflective layer 4 and the electrode 6 of the rear substrate 3 of the liquid crystal display element 1 of FIG. It has a different structure. 3, the same components as those in FIG. 1 are designated by the same reference numerals.

The rear substrate 3 of FIG. 3 has a reflective layer 4, a color filter 32, a flattening layer 33, an electrode 6 and an alignment film 8 in this order on its inner surface. The configuration other than the color filter 32 and the flattening layer 33 in FIG. 3 is as described in FIG.

The color filter 32 is constructed by providing filters of three primary colors of RGB (Red, Green, Blue) corresponding to each dot of the pixel, and controls the transmittance of each primary color for each dot. This allows color display. As the color filter 32, it is preferable to use one having a lower absorbance than a normal transmissive LCD color filter. Filters with low absorbance are used because in a reflection type liquid crystal display device, light passes through the color filter twice at the time of incidence and at the time of reflection, so that light passes twice even if the predetermined color is not obtained at one time. By doing so, a predetermined color is obtained and high color reproducibility is obtained. When the color filter used in the transmissive liquid crystal display element is used for the reflective liquid crystal display element, the light loss becomes large and the image becomes dark by passing through the color filter twice.

The position of the color filter 32 is provided close to the reflection layer 4 in FIG. 3, but it may be arranged at any position on the front side of the reflection layer 4, for example, the front substrate 2 and the transparent electrode. It may be provided between the five.

In the liquid crystal display element 31 shown in FIG. 3, the cell gap, the retardation value of the retardation plate 12, the angle α, the angle β and the angle γ are set in the same manner as in FIG. Since black can be displayed and the contrast can be increased, high-quality display can be performed. Moreover, since the liquid crystal display element can be configured by one retardation plate 12, the number of parts can be reduced, and the number of steps and the cost can be reduced.

Further, a liquid crystal display element 41 of the active matrix type in which the present invention is embodied, in which the reflective layer also serves as an electrode, will be described with reference to FIG. FIG. 4 is a schematic diagram of a cross-sectional structure of the liquid crystal display element 41. In order to perform active matrix driving, a TFT (Thin Film Transistor) is used as an active element on the rear substrate 3 of the liquid crystal display element of FIG.
(tor: thin film transistor) 42 is provided.
In addition, FIG. 4 shows the reflective layer 43 and the insulating layer 44 which also serve as the pixel electrode connected to the TFT. Figure 4
In FIG. 1, the same components as those in FIG. 1 are designated by the same reference numerals.

The rear substrate 3 of FIG. 4 has a T-shaped surface on its inner surface.
It has an FT 42, a pixel electrode 43, an insulating layer 44, and an alignment film 8. The configuration other than the TFT 42, the pixel electrode 43, and the insulating layer 44 in FIG. 4 is as described in FIG.

The TFT 42 is an active element which is provided for each pixel in order to perform active matrix driving and functions so that different voltages can be applied to each pixel. Currently, TFTs using amorphous silicon or polycrystalline silicon are widely used. TFT in the present invention
The structure of is not limited to the inverted stagger type shown in FIG. 4, and a conventionally used structure can be used. Further, as an active element, a TFD (Thin Fi
lm Diode (thin film diode) may be used.

The reflective layer 43 is connected to the drain of the TFT 42 and also serves as the pixel electrode of each pixel. Similar to the reflective layer of FIG. 1, it is preferable to use a metal material for the reflective layer 43, and it is particularly preferable to use aluminum having both high conductivity and high reflectance.

The insulating layer 44 is composed of a stack of a plurality of insulating films, and the TFTs are formed between the respective constituent parts of the TFT 42.
It has a function of insulating between 42 and the reflective layer 43 and between TFTs. Also, as shown, the insulating layer 44
It is preferable to flatten the surface and form the alignment film 8 on the flat surface because the nematic liquid crystal material 11 can be regularly aligned. As the insulating layer 44,
An inorganic insulator such as silicon oxide, silicon nitride, or silicon oxynitride, or an organic insulator such as an acrylic type, an epoxy type, or an imide type can be used. Particularly for planarization, it is preferable to spin coat using an organic insulator.

A color filter may be provided between the insulating layer 44 and the alignment film 8 or between the front substrate 2 and the electrode 5 in order to display the liquid crystal display element 41 shown in FIG. 4 in color. .

In the liquid crystal display element 41 shown in FIG. 4, the cell gap, the retardation value of the retardation plate 12, the angles α, β and γ are set in the same manner as in FIG. Since black can be displayed and the contrast can be enhanced, high-quality display can be achieved. Moreover, since the liquid crystal display element can be formed by one retardation plate 12, the number of parts can be reduced, and the number of steps and the cost can be reduced.

The present invention is not limited to the above-mentioned embodiment, but various modifications can be made if necessary.

[0039]

EXAMPLES Next, a negative reflection type liquid crystal display device embodying the present invention is manufactured and evaluated by comparing with the optical characteristics of the conventional liquid crystal display device.

In this embodiment, the liquid crystal display element 1 shown in FIG.
To manufacture. First, a transparent glass substrate manufactured by the float method was used as the front substrate 2, and an ITO film was formed on one surface (a surface to be an inner surface later) of the transparent glass substrate and patterned into a predetermined shape to form an electrode 5. . Then, an alignment film 7 was formed on the electrode 5, and the alignment film 7 was rubbed.

Next, a transparent glass substrate manufactured by the float method is used as the rear substrate 3, and a reflective layer 4 made of aluminum is formed on one surface (a surface which will be an inner surface later) of the transparent glass substrate. An acrylic resin was spin-coated on the above to form a flattening layer (not shown). Then, an ITO film was formed on the flattening layer and patterned into a predetermined shape to form the electrode 6. An alignment film 8 was formed on the electrode 6, and the alignment film 8 was rubbed.

The spacers 9 are dispersed so that the cell gap becomes 3.25 μm, and the front substrate 2 and the front substrate 2 are arranged so that the crossing angle γ between the rubbing direction of the alignment film 7 and the rubbing direction of the alignment film 8 is 85 °. The inner surface of the rear substrate 3 was made to face each other, and the periphery was surrounded by the sealing material 10. Then, the nematic liquid crystal material 11 is injected into the space formed by the two substrates and the sealing material, and the injection hole is sealed to seal the nematic liquid crystal material 11. Here, the twist angle of the nematic liquid crystal material 11 was about 95 °, and the pretilt angle was about 1 °.

Then, on the outer surface of the front substrate 2, a retardation plate 12 made of JSR's Arton material having a retardation value of 70 nm is provided. Further, the polarizing plate 13 is provided on the retardation plate 12 so that the crossing angle β with the slow axis of the polarizing plate 13 becomes 125 °, and the rubbing direction of the alignment film 7 of the front substrate 2 and the absorption axis of the polarizing plate 13. The reflection type liquid crystal display element 1 was completed by arranging so that the intersection angle α with and was 15 °.

[Comparative Example 1] As one comparative example, FIG.
A liquid crystal display element 101 having the structure shown in (1) and the following design conditions was prepared. The cell gap of the liquid crystal display element 101 is 3.5 μm, the pretilt angle is about 1 °, and the phase difference value of the ¼ wavelength phase difference plate 112 a is 140 n.
m, and the retardation value of the half-wave retarder 112b is 2
70 nm.

When the liquid crystal display element 101 is viewed from the front side, the clockwise angle between the rubbing direction of the alignment film 107 and the rubbing direction of the alignment film 108 is 109 °, and 1 / The clockwise angle with the slow axis of the 4-wavelength phase difference plate 112a is 34 °, the clockwise angle with the slow axis of the ½ wavelength phase difference plate 112b is 114 °, The clockwise angle between the absorption axis of the polarizing plate 113 and the absorption axis is 14 °.

[Comparative Example 2] As another comparative example,
A liquid crystal display element 101 having the structure shown in FIG. 6 and the following design conditions was prepared. The liquid crystal display element 101 has a cell gap of 3.25 μm and a pretilt angle of about 1
And the phase difference value of the quarter-wave retarder 112a is 1
40 nm, and the retardation value of the half-wave retardation plate 112b is 270 nm.

When the liquid crystal display element 101 is viewed from the front side, a clockwise angle between the rubbing direction of the alignment film 107 and the rubbing direction of the alignment film 108 is 114 °, and 1 / The clockwise angle between the four-wavelength phase difference plate 112a and the slow axis is 127 °, which is 1/2
The clockwise angle with the slow axis of the wavelength retardation plate 112b is 27 °, and the clockwise angle with the absorption axis of the polarizing plate 113 is 107 °.

With respect to the liquid crystal display element 1 which is an example of the present invention and the liquid crystal display elements 101 of Comparative Examples 1 and 2, the chromaticity coordinates, reflectance and contrast during black display and white display were measured. The measurement of chromaticity coordinates and reflectance is
A ring light with a diameter of 100 mm was adjusted to a position of 187 mm above the liquid crystal display element so that light was incident at an angle of 15 ° with respect to the vertical direction of the liquid crystal display element.
Performed using an S-1000 spectrophotometer.

FIG. 5 is a chromaticity diagram showing the measurement result of the above chromaticity coordinates. In FIG. 5, the chromaticity coordinates of the liquid crystal display element 1 (embodiment) embodying the present invention are (0.316, 0.331) during white display (displayed with a circle in the figure) and during black display ( (Indicated by ● in the figure) is (0.313, 0.2
63). The chromaticity coordinates of the liquid crystal display element 101 of Comparative Example 1 (Comparative Example 1) are (0.316, 0.323) when white is displayed (displayed by Δ in the figure) and when black is displayed (▲ in the figure).
(Displayed with) was (0.295, 0.225). The chromaticity coordinates of the liquid crystal display element 101 (Comparative Example 1) of Comparative Example 2 are
White display (indicated by □ in the figure) is (0.325, 0.34
0), and during black display (displayed with ■ in the figure) is (0.28
8, 0.250). Further, in FIG. 5, the coordinates (0.310, 0 ..
316) is shown for reference.

From FIG. 5, in white display, the chromaticity coordinates (◯) of the example are the chromaticity coordinates (Δ, □) of Comparative Examples 1 and 2.
And both are almost the same white,
It can be seen that in the black display, the chromaticity coordinates of the two are distant from each other, and the black displays of the both are different. Regarding the black display, the chromaticity coordinates (●) of the example are closer to the chromaticity coordinates (*) of the C light source than the chromaticity coordinates (▲, ■) of Comparative Examples 1 and 2, and thus are more achromatic. Has become. By visual observation, it was confirmed that the black color of the liquid crystal display element 101 was more bluish than the black color of the liquid crystal display element 1.

Next, Table 1 shows the reflectance and the contrast during black display and white display.

[0052]

[Table 1]

From Table 1, in white display, the reflectance of the embodiment is close to that of Comparative Examples 1 and 2, and the brightness of both is almost the same, but in the black display, the reflectance of the embodiment is compared. It can be seen that the reflectance of the liquid crystal display element 1 is darker, which is about half the reflectance of Examples 1 and 2. As a result, the liquid crystal display element 1 embodying the present invention was able to obtain about twice the contrast of the conventional liquid crystal display element 101.

[0054]

As described above, the liquid crystal display device of the present invention can display a more achromatic black color and can also increase the contrast, and thus can display a high quality image. Moreover, since the liquid crystal display element can be configured by one retardation plate, the number of parts can be reduced, and the number of steps and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic view of a cross-sectional structure of a liquid crystal display device using the present invention.

FIG. 2 is a diagram showing a positional relationship among a rubbing direction of an alignment film, a slow axis of a retardation plate and an absorption axis of a polarizing plate of a liquid crystal display device using the present invention.

FIG. 3 is a schematic view of a cross-sectional structure of a liquid crystal display device using the present invention.

FIG. 4 is a schematic view of a cross-sectional structure of a liquid crystal display device using the present invention.

FIG. 5: Chromaticity diagram showing the measurement results of chromaticity coordinates

FIG. 6 is a schematic view of a cross-sectional structure of a conventional liquid crystal display element.

[Explanation of symbols]

1, 31, 41, 101 Liquid crystal display element 2, 102 Front side substrate 3, 103 Back side substrate 4, 104 Reflective layer 5, 6, 105, 106 Electrode 7, 8, 107, 108 Alignment film 9, 109 Spacer 10, 110 Sealing Material 11, 111 Liquid Crystal Material 12 Phase Difference Plate 13, 113 Polarizing Plate 14 Rubbing Direction of Alignment Film of Front Side Substrate 15 Absorption Axis 16 of Polarizing Plate Slow Phase Axis 17 of Phase Difference Plate 17 Rubbing Alignment Film of Back Side Substrate Direction 32 Color filter 33 Flattening layer 42 TFT 43 Pixel electrode 44 Insulating layer 112a 1/4 wavelength retardation plate 112b 1/2 wavelength retardation plate

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2H088 GA02 HA02 HA03 HA15 HA18                       HA21 JA04 KA02 KA07 KA17                       MA07                 2H090 LA01 LA06 LA09 LA20 MA02                       MB01                 2H091 FA08X FA11X FA14Y FD09                       FD10 GA02 GA06 HA06 KA02                       KA10 LA19

Claims (4)

[Claims] 1. A front side substrate and a rear side substrate each having an electrode and an alignment film on an inner surface thereof, wherein a nematic liquid crystal is sealed between the front side substrate and the rear side substrate, and the front side substrate is provided. In a negative type liquid crystal display device having a retardation plate and a polarizing plate on the outer surface of the substrate in this order, the back side substrate has a reflective layer that reflects light incident from the front side, The retardation value is 65 to 75 nm, and the rubbing direction of the alignment film on the front substrate is used as a reference.
The angle formed by the absorption axis of the polarizing plate is α, the angle formed by the slow axis of the retardation plate is β, and the rubbing of the alignment film of the rear substrate is clockwise when viewed from the front side of the liquid crystal display element. When the angle formed by the direction is γ, α, β and γ are 10
° ≦ α ≦ 20 °, 115 ° ≦ β ≦ 135 ° and 80 °
A reflection type liquid crystal display device characterized by satisfying ≦ γ ≦ 90 °. 2. A reflective liquid crystal display device according to claim 1, wherein the nematic liquid crystal has a retardation value of 234 to 273 nm. 3. The reflective liquid crystal display element according to claim 2, wherein the cell gap between the front substrate and the rear substrate is 3.0 to 3.5 μm. 4. The reflective type structure according to claim 1, wherein the reflective layer also serves as the electrode provided on the inner surface of the rear substrate. Liquid crystal display device.