JP2930517B2 - Method for manufacturing reflective liquid crystal display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflection type liquid crystal display device which performs display by reflecting incident polarized light on a reflection plate.

[0002]

2. Description of the Related Art The most important performance required for a reflective LCD (Liquid Crystal Display) is how to effectively utilize ambient light. At present, a display mode generally used for calculators, word processors, and the like is a TN (twisted nematic) system in which two polarizing plates and a reflecting plate are combined.

However, in such a system using two polarizing plates, one of a circularly polarized light or an elliptically polarized reflected light obtained by reflecting incident light on a reflecting plate is orthogonal to the linearly polarized light component. Either one of the linearly polarized light components and the linearly polarized light component in the direction is blocked by the polarizing plate.
Thereby, since the loss of light by the polarizing plate is large,
There is a problem that a bright display cannot be obtained.

Therefore, a reflection type LCD using a WT (white tailor) type display mode in which a dichroic dye and a liquid crystal are combined has been proposed as a display mode without using a polarizing plate. However, since this display mode is based on the cholesteric-nematic phase transition of the liquid crystal, a domain is formed in the liquid crystal at a voltage halfway until the drive voltage applied to the liquid crystal reaches the saturation voltage, and the domain forms an optical signal. Because of scattering, gradation display is difficult.

[0005] As a display mode in which a gray scale display is possible and a bright display is obtained, an ECB (Electric Field Controlled Birefringence) mode using one polarizing plate (Nakamura et al., 18th Liquid Crystal Discussion 3D110) has been proposed. I have.

FIG. 8 shows the operation principle of this display mode.
The liquid crystal display device 1 shown in FIG. 8 includes a polarizing plate 2, a retardation plate 3, a liquid crystal layer 4, and a reflecting plate 5. Fig. 8 (1)
In the dark state shown in FIG. 7, the apparent retardation Δn · d when the liquid crystal layer 4 and the phase difference plate 3 are combined is λ / 4
Since the condition is satisfied, the linearly polarized light incident as shown by the arrow A1 passes through the liquid crystal layer 4 and the phase difference plate 3 and then passes through the arrow A2.
After being reflected by the reflection plate 5, the light becomes circularly polarized light in the opposite direction to the direction of the arrow A2 as shown by the arrow A3. Further, after passing through the liquid crystal layer 4 and the phase difference plate 3, the light becomes a linearly polarized light rotated by 90 ° from the direction of the linearly polarized light at the time of incidence, and the light is blocked by the polarizing plate 2.

On the other hand, in the bright state shown in FIG.
Since the apparent retardation Δn · d is 0, the incident linearly polarized light does not change its polarization state even after being reflected by the reflector 5, and the reflected light passes through the polarizer 2. In this manner, display can be realized in the ECB mode.

[0008]

By the way, as a reflector used in this display mode, even if linearly polarized light incident in a bright state is reflected, it is retained as linearly polarized light, and circularly polarized light incident in a dark state is reflected. Even if they are not kept in circularly polarized light, good contrast cannot be obtained,
The display quality will be degraded. Therefore, in order to improve the display quality of the reflection type liquid crystal display device, as described above, the incident linearly polarized light is favorably maintained as the linearly polarized light even after the reflection, and the incident elliptically polarized light remains the same after the reflection. Need to be held to be

The present invention has been made to solve such a problem, and an object of the present invention is to provide a reflection plate whose display quality is remarkably improved by providing a reflection plate having a good polarization degree after reflection. It is an object of the present invention to provide a reflective liquid crystal display device, and to provide a method of manufacturing a reflective liquid crystal display device capable of significantly improving the display quality of the manufactured reflective liquid crystal display device.

[0010]

[0011]

[0012]

[0013]

[0014]

[0015]

[0016]

[0017]

[0018]

[0019]

[0020]

According to a method of manufacturing a reflection type liquid crystal display device of the present invention, the reflection type liquid crystal display device is arranged on a light incident side, has electrical insulation and translucency, and has a transparent electrode formed on one side. A first substrate, a second substrate having electrical insulation, and a second substrate having a light reflecting member disposed opposite to the first substrate via a liquid crystal layer and reflecting incident light; Reflective liquid crystal display device comprising: a polarizing plate provided on the light incident side
In the manufacturing method, the liquid crystal layer on the second substrate is
Applying an edge film, and exposing and developing the organic insulating film
Processing to form a plurality of irregularities, and the plurality of irregularities
Heat-treating to form smooth irregularities ;
Organic insulating film on the smooth irregularities along the smooth irregularities
Forming a light reflecting member on the organic insulating film
And a step of, degree of polarization V of the following formulas of the reflected light by the light reflecting member

[0021]

(Equation 4)

S ₀ , S ₁ , S ₂ , S ₃ : Stokes parameters of reflected light obtained by making circularly polarized light incident on the light reflecting member.

S ₁ : horizontal linearly polarized light component, S ₂ : 45 ° linearly polarized light component, S ₃ : right circularly polarized light component, S ₀ : light intensity is selected so as to be at least 50% or more.
It achieves the above-mentioned object.

[0024]

By using a light-reflecting member having the characteristics of the present invention in a reflection-type liquid crystal display device, the degree of polarization of the light-reflecting member can be significantly improved, and after the incident linearly polarized light is reflected by the reflecting member. Are also favorably held in linearly polarized light, and are favorably maintained such that incident elliptically polarized light remains the same elliptically polarized light even after reflection. As a result, the present invention can realize a reflective liquid crystal display device having a better contrast than ever before.

Further, when parallax is a problem, the reflecting member having the reflecting function is arranged on the liquid crystal layer side of the second substrate, that is, at a position substantially adjacent to the liquid crystal layer. be able to.

The reflecting member having the reflecting function is:
It may be an insulating thin film of a notch type filter using a dielectric mirror or cholesteric liquid crystal, but may be a metal thin film. Further, in this case, a function as an electrode opposed to the transparent electrode formed on the light-transmitting first substrate with the liquid crystal layer interposed therebetween can be provided.

[0027]

【Example】

(Example 1) Hereinafter, Example 1 of the present invention will be specifically described. FIG. 5 shows a manufacturing process of the reflective liquid crystal display device used in the first embodiment of the reflective liquid crystal display device of the present invention.
As shown in FIG. 5A, a glass substrate 5 having a thickness of 1.1 mm
1 (trade name 7059, manufactured by Corning Incorporated)
As a resist material, for example, a resist layer 52 made of OFPR-800 (manufactured by Tokyo Ohka Co., Ltd.) is preferably used.
r. p. m-3000 r. p. Spin coat at a rotation speed of m. In this embodiment, first, 3000r. p. The resist layer 52 is applied at a rotation speed of m for 30 seconds.
2 was formed in a thickness of 1.2 μm. Next, at 100 ° C., 3
After pre-baking for 0 minutes, a photomask 53 having a predetermined pattern formed thereon is arranged, exposed, and developed (NMD-
3, 2.3% by Tokyo Ohka Co., Ltd.) to form fine irregularities on the surface of the glass substrate 51 (FIG. 5 (3)).

The unevenness on the glass substrate 51 is preferably
When heat treatment is performed at 20 to 250 ° C., the corners of the irregularities are deformed by heat to form smooth irregularities (FIG. 5).
(4)). In this embodiment, first, heat treatment was performed at 180 ° C. for 30 minutes. Further, a polyimide resin is preferably used as the organic insulating film 54 on the glass substrate 51 on which the concave and convex portions are formed.
3500r. p. Spin coat at a rotation speed of m for 20 seconds. In this embodiment, first, 2200 r. p. The coating was performed at a rotation speed of m for 20 seconds to form an organic insulating film 54 having a thickness of 1 μm, thereby forming a smoother uneven portion in which the difference in height of the unevenness was suppressed. Further, a metal thin film 55 was formed on the organic insulating film 54 (FIG. 5 (5)). Examples of the material of the metal thin film 55 include Al, Ni, Cr, and Ag. The thickness of the metal thin film 55 is suitably about 0.01 to 1.0 μm. Preferably, it is 0.1 to 0.5 μm. In this example, a metal thin film was formed by vacuum deposition of Al.

Several types of reflectors were manufactured under conditions other than the resist application conditions, heat treatment conditions, and polyimide resin application conditions described above.

The reflector obtained as described above is used as the reflector 21 in FIG.
And the Stokes parameter of the reflected polarized light was measured.

FIG. 2 shows a method for measuring the degree of polarization of light reflected by the reflector 21. 20 from the perpendicular to the reflector 21
The light source 22 is placed at an angle of ゜, and the light is
The light is converted into circularly polarized light by the four-wavelength plate 24 and is incident on the reflection plate 21.
The regular reflection direction is set to 0 °, and the power meter 25 is placed at an angle θ (θ = 30 °) shifted from the regular reflection. Power meter 25
A polarizing plate 26 and a quarter-wave plate 27 are placed between the reflector and the reflecting plate 21. The Stokes parameters are measured by changing the directions of the transmission axis of the polarizing plate 26 and the optical axis of the quarter-wave plate 27.
Here, the display and measurement method of Stokes parameters and the degree of polarization are described in detail in the following documents. The degree of polarization expressed here is based on the Stokes parameter described on pages 137 to 140 of “Latest Applied Physics Series 1 Crystal Optics” (editor, Japan Society of Applied Physics, Optical Society, published by Morikita Publishing). It is the same as the degree of polarization used. This document describes in detail the method of measuring the Stokes parameter and the definition formula of the degree of polarization using the Stokes parameter. The Stokes parameters are shown below.

[0032]

S ₀ = <| E _x | ² > + <| E _y | ² >

[0033]

S ₁ = <| E _x | ² >-<| E _y | ² >

[0034]

S ₂ = <2E _x E _y cos δ>

[0035]

S ₃ = <2E _x E _y sin δ> where δ = ψ _y −ψ _x S ₀ , S ₁ , S ₂ , and S _{3 in the} above _equations 5 to 8 are Stokes parameters. Variable E _x, the E _y is the X-axis direction, the light intensity of the Y-axis direction, variable phi _x, phi _y are the X-axis direction, Y axis direction of the light wave phase. Also, the meaning of each Stokes parameter is a horizontal linear polarization component of S ₁ , S ₂ is a 45 ° linear polarization component,
S ₃ is the right circularly polarized light component, S ₀ is the light intensity. The following Expression 9 shows an example of a typical polarization state.

[0036]

(Equation 9)

Vertical linearly polarized light orthogonal to these states,
The 45 ° linearly polarized light component and the left circularly polarized light component are expressed as negative quantities of the Stokes parameters S ₂ , S ₃ and S ₄ , respectively.

For perfectly polarized light,

[0039]

S ₀ ² = S ₁ ² + S ₂ ² + S ₃ ² , and all four parameters are not independent. For partially polarized light,

[0040]

Equation 11] _{^{S 0 2> S 1 2 +}} S 2 2 + S 3 2 , and the degree of polarization is calculated as follows as the ratio of full polarization component intensity of the total intensity.

[0041]

(Equation 12)

The state vector of natural light is x,
Since the intensity of the y component is equal and both components are not correlated with each other,

[0043]

(Equation 13)

Is obtained.

The method of measuring the Stokes parameter is as follows.
On pages 106 to 107 of "Optical Technology Handbook" (edited by Hiroshi Kubota, Asakura Shoten Publishing Co., Ltd.), the transmission axis of the polarizing plate and the optical axis of the quarter-wave plate are shown. The measurement method is described below.

Here, the parameter of Stokes is I,
It is represented using the symbols Q, U and V. Although the symbol is different from that of the above-mentioned document "Latest Applied Physics Series 1 Crystal Optics", the following table shows a comparison with Stokes parameters in particular.

[0047]

[Table 1]

Based on the above, the measurement method is represented by the following scheme.

FIG. 3 shows a measurement system.

The Stokes parameters I, Q, U and V are not measured independently, but are shown in FIGS.
As shown in (d), the Stokes parameter can be obtained by measuring the light intensity while changing the optical axis of the quarter-wave plate and the transmission axis of the polarizing plate, and solving the simultaneous equations of the following equations (14) to (17).

[0051]

１４ (I + Q) = i (a)

[0052]

１５ (I−Q) = i (b)

[0053]

１６ (I + U) = i (c)

[0054]

１７ (I + V) = i (d) That is, the functions i (a) to i (d) were measured with the polarizing plate and the phase difference plate in the state shown in FIGS. Figure 4
The Stokes parameters I, Q, U, and V in Table 1 can be obtained by performing the measurements (a) to (d) and solving the simultaneous equations of Equations 14 to 17 above.

Next, the structure of a reflection type liquid crystal cell using the reflection plate produced by the above-mentioned production method and the production method will be described. In FIG.
1 is a cross-sectional view of a reflection type liquid crystal display device according to the present embodiment using a reflection plate 75. FIG. ITO (Indium Tin Ox)
a) a glass substrate 71 on which a transparent electrode 72 made of ide) is formed, and a reflection plate 75 including the glass substrate 51, the resist layer 52, the organic insulating film 54, and the metal thin film 55.
A polyimide resin was formed as the liquid crystal alignment film 73, and baked at 200 ° C. for 1 hour. Thereafter, a rubbing process is performed on the liquid crystal alignment film 73 to align the liquid crystal molecules,
A 5 μm spacer was sprayed and bonded so as to form a parallel alignment cell. These two glass substrates 51,
Between 71, a liquid crystal sealing layer (omitted in the figure) is formed. This liquid crystal satire layer is formed by screen-printing an adhesive sealant mixed with a 5.5 μm spacer. The liquid crystal layer 74 is a liquid crystal sealing layer (omitted in the drawing).
, And then sealed by vacuum degassing. In the present embodiment, the liquid crystal layer (ZLI, trade name, manufactured by Merck Ltd.)
2459) was used. The optical anisotropy Δn of the liquid crystal is 0.1
1. Since the cell thickness d is about 5 μm, the retardation Δn · d of this liquid crystal layer is 550 nm.

FIG. 6 shows a method of applying a voltage to the reflective liquid crystal cell 61 to measure the ratio of the reflectance (contrast ratio) between the on state and the off state. The incident light 62 enters the liquid crystal cell 61 at an angle of 20 ° from the vertical direction, passes through the polarizing plate 63 and the phase difference plate 64, passes through the liquid crystal phase and is reflected by the reflection plate, and the liquid crystal phase and the phase difference plate 67 The maximum value (ON state) and the minimum value (OFF state) of the reflected light are measured by the power meter 65 after passing through the polarizing plate 66. The measurement angle θ is θ = 30
°.

FIG. 1 shows the degree of polarization of several types of reflectors and the contrast characteristics of an ECB mode reflective LCD using the reflectors and using one polarizer.

As described above, maintaining the degree of polarization in this display mode is the point of improving the contrast. From FIG. 1, it can be seen that a sharp change in contrast appears after the polarization degree exceeds 50%.
If the contrast is 4 or less as a practical reflection type LCD, it cannot be put to practical use because of the deterioration of display quality. Therefore, the degree of polarization is required to be 50% or more from FIG. Preferably, a contrast ratio of 7 or more is required, and the degree of polarization is 7
0% or more is required.

(Embodiment 2) FIG. 9 shows a manufacturing process of an active matrix substrate used in this embodiment. First, on an insulating substrate made of glass, 3
A Ta metal layer having a thickness of 00 nm was formed, and the metal layer was patterned by photolithography and etching to form a gate bus wiring and a gate electrode.
Incidentally, for example, Ta ₂ O ₅ may be provided on the upper portion to protect the gate bus wiring and the gate electrode (S1). Next, 400 nm is formed by a plasma CVD (chemical vapor deposition) method.
A gate insulating film (S2) made of SiN _x having a thickness of 100 nm, an a-Si layer having a thickness of 100 nm to be a semiconductor layer later, and an n ⁺ -type a-Si layer having a thickness of 40 nm to be a contact layer later. They were formed continuously in this order (S3). Next, the n ⁺ type a
The contact layer and the semiconductor layer were formed by patterning the -Si layer and the a-Si layer (S3).

Next, the entire surface of the substrate is coated with a thickness of 200 n.
m Mo metal was formed by a sputtering method, and the Mo metal layer was patterned to form a source electrode, a drain electrode, and a source bus wiring (S4). As described above, the TFT is completed. Next, the unevenness is formed on the substrate on which the TFT is formed by the method and the material described in the first embodiment (S5 to S5).
S8) Further, a contact hole was formed in the organic insulating layer by photolithography in the organic insulating layer (S8).
6). Further, an aluminum film was formed on the entire surface on the irregularities (S9) to obtain a reflective electrode.

FIG. 10 is a sectional view of a reflection type color liquid crystal display device manufactured using the reflection type active matrix substrate 81 according to the present embodiment. For example, the surface of the complementary color filter 96 for magenta and green is entirely covered with ITO.
A transparent electrode 97 made of (Indium Tin Oxide) was formed with a thickness of 100 nm. Liquid crystal alignment films 94 and 98 are provided on the surfaces of the transparent electrode 97 of the reflective active matrix substrate 81 and the complementary color filter substrate 95, respectively.
Was applied and then fired. Between these two substrates, a liquid crystal sealing layer (omitted in the figure) is formed by screen printing an adhesive sealant mixed with a 5 μm spacer. The liquid crystal layer 99 is a liquid crystal sealing layer (omitted in the figure).
, And then sealed by vacuum degassing. The liquid crystal used was the same as the liquid crystal used in Example 1. Alternatively, cyan and red, blue and yellow, or an RGB system may be used for the color filter.

The same polarization degree-contrast characteristics as in Example 1 were measured using the reflection type liquid crystal display device prepared as described above, and it was confirmed that the same result as in FIG. 1 was obtained.

In the reflection type liquid crystal display device of this embodiment, the reflection electrode 8 of the reflection type active matrix substrate 81 is used.
Since the surface on which 8 is formed is disposed on the liquid crystal layer side, there is no parallax, and a good display screen can be obtained.

Although a glass substrate is used as a substrate in this embodiment, an opaque substrate such as a Si substrate has a similar effect. In this case, there is an advantage that circuits can be integrated on the substrate.

(Embodiment 3) FIG. 11 shows a manufacturing process of a reflection plate used in the reflection type liquid crystal display device shown in this embodiment.
As shown in FIG. 11A, an organic insulating film 112 made of a polyimide resin is preferably formed on the TFT element side of the active matrix substrate 111 described in the second embodiment.
500r. p. Spin coat at a rotation speed of m for 20 seconds. On the upper surface, for example, OFPR-8 as a resist material
00 (manufactured by Tokyo Ohkasha Co., Ltd.), preferably 500 r. p. m-3000 r. p. Spin coat at a rotation speed of m. In this embodiment, 3000 r. p.
m at a rotation speed of 30 m, and the resist layer 113
The film was formed with a thickness of 2 μm. Next, after prebaking at 100 ° C. for 30 minutes, a photomask 114 on which a predetermined pattern is formed is arranged, exposed, and developed (NMD-3, 2.3).
8% (manufactured by Tokyo Ohkasha Co., Ltd.) to form fine irregularities on the surface (FIG. 11 (4)). Glass substrate 1
When the unevenness on the surface 11 is heat-treated at preferably 120 to 250 ° C., a smooth uneven surface is formed as described above (FIG. 1 (5)). 180 ° C. in this embodiment
For 30 minutes.

Further, the glass substrate 111 having the uneven portions formed thereon
Dry etching process from the upper surface of the organic insulating film 1
15 is formed into the shape shown in FIG. An organic insulating film 115 made of a polyimide resin is again preferably formed on the smooth and uneven organic insulating film 115, preferably at 920 to 3500 rpm.
p. Spin coat at a rotation speed of m for 20 seconds. In this embodiment, 2200 r. p. The coating was performed at a rotation speed of m for 20 seconds, the organic insulating film 115 was formed to a thickness of 1 μm, and smoother projections were formed. Further, a metal thin film 116 was formed on the organic insulating film 115 (FIG. 11 (8)). Examples of the metal thin film 116 include A1, Ni, Cr, and Ag. The thickness of the metal thin film 116 is 0.01 to
1.0 μm is suitable. In this example, a metal thin film was formed by vacuum deposition of Al.

A reflection type liquid crystal cell was prepared in the same manner as in Example 2 by using the active matrix substrate having the unevenness as described above, and the polarization degree-contrast characteristics were measured. It was confirmed that the result was good.

Embodiment 4 FIG. 12 shows a reflection type liquid crystal display device shown in this embodiment. This corresponds to FIG. 7 described in the first embodiment.
Is an example in which the light reflecting plate 85 is disposed outside a pair of light-transmitting substrates that are disposed to face each other with a liquid crystal layer interposed therebetween. In the case of this reflection type liquid crystal display device, parallax occurs because the light reflection plate is not in direct contact with the liquid crystal layer, but as a result of measuring the contrast by the measurement method of FIG.
A contrast characteristic was obtained.

(Embodiment 5) In this embodiment, the case where the phase difference plate is not used in the display mode shown in Embodiment 1 (method of displaying by the measurement system of FIG. 6 using the liquid crystal cell of FIG. 7) will be described. I do. FIG. 13 is a sectional view of the reflection type liquid crystal display device of the present embodiment. When the phase difference plates 64 and 67 in FIG. 6 are not used, the twist angle of the liquid crystal layer, the angle of the polarizer, and the like are set so that only the liquid crystal layer 61 becomes circularly polarized light. When the contrast of the display device thus manufactured was measured, the same degree of polarization-contrast characteristics as in Example 1 were obtained. However, in the contrast measurement, the polarizing plate of FIG. 13 was removed.

(Embodiment 6) In this embodiment, a case will be described in which the reflector is disposed outside the liquid crystal cell in the display mode shown in Embodiment 5. FIG. 14 is a sectional view of the liquid crystal display device shown in this embodiment. In this case, Example 4
However, when the contrast was measured, the same degree of polarization-contrast characteristics as in Example 1 were obtained. However, in the contrast measurement, the polarizing plate in FIG. 14 was removed.

(Embodiment 7) In the above embodiment, a display mode in which one polarizing plate and one polarizing plate are aligned in parallel using a retardation plate is taken as a display mode, but in this embodiment, one polarizing plate is used as a display mode. The STN mode in which the phase difference plate and the liquid crystal layer are twisted by about 240 ° will be described.

A transparent electrode ITO (Indium) is provided on the opposite substrate.
A polyimide resin was formed as a liquid crystal alignment film on the glass substrate on which Tin Oxide was formed and the reflection plate prepared in Example 1, and baked at 200 ° C. for 1 hour. After that, a rubbing process is performed to align the liquid crystal molecules, and the rubbing process is performed at about 240 °.
A liquid crystal cell is created by bonding both substrates in a twisted manner. Between these two substrates, a liquid crystal sealing layer is screen-printed with an adhesive sealant mixed with a spacer having a diameter of 6.5 μm. Is formed by The liquid crystal layer is sealed by vacuum degassing after forming the liquid crystal sealing layer. In this embodiment, the liquid crystal layer has a trade name of ZLI4
427 (Merck) was used. The retardation of the liquid crystal layer is 650 nm, the same polarizing plate as that used in Example 1 is used, and the retardation of the retardation plate is 350.
nm.

The angle β between the transmission axis of the polarizing plate and the arrangement direction of the liquid crystal molecules adjacent to the polarization plate, and the angle between the slow axis of the retardation plate and the alignment direction of the liquid crystal molecules adjacent to the retardation plate γ is

[0074]

[Expression 18] 0.5β + 45 ° m + 7.5 ° ≦ γ ≦ 0.5
Each axis was set so as to satisfy the relationship of β + 45 ° m + 27.5 ° (m is an integer). When the contrast of the display device thus manufactured was measured, the same degree of polarization-contrast characteristics as in Example 1 were obtained. However, in contrast measurement, FIG.
The polarizing plate of No. 3 has been removed. In the above-described embodiment, a display mode in which one polarizing plate is aligned in parallel by using one polarizing plate and a phase difference plate, and a mode in which twist alignment is performed are taken as examples of the display mode. The reflection type active matrix substrate according to the present invention, such as a birefringence display mode used in an LCD, and its application to a panel configuration method are possible.

The case where a TFT is used as a switching element has been described below. However, for example, an MIM (Metal
-Insulator-Metal) can be applied to an active matrix substrate using an element, a diode, a varistor, or the like.

The method of patterning a photosensitive resin as a reflection plate and the method of dry etching have been described.
In addition, a sandblasting method, a wet etching method, and the like are also effective production methods and can be applied.

[0077]

According to the present invention, by using a light reflecting member having the features of the present invention in a reflection type liquid crystal display device, the degree of polarization of the light reflecting member can be remarkably improved, and incident linearly polarized light can be reduced. Even after being reflected by the reflecting member, it is satisfactorily maintained as linearly polarized light, and the elliptically polarized light that is incident is well maintained so as to be the same elliptically polarized light even after reflection. As a result, the present invention can realize a reflective liquid crystal display device having a better contrast than ever before.

[Brief description of the drawings]

FIG. 1 is a diagram showing a degree of polarization-contrast characteristic of a reflection type liquid crystal display device of the present invention.

FIG. 2 is a system diagram showing a method for measuring a Stokes parameter of light reflected by a reflector.

FIG. 3 is a system diagram showing a measurement system of Stokes parameters.

FIG. 4 is a diagram showing the principle of measurement of Stokes parameters.

FIG. 5 is a cross-sectional view showing one embodiment of a method for producing a reflector according to the present invention.

FIG. 6 is a system diagram showing a method for measuring the contrast of the reflective liquid crystal display device of the present invention.

FIG. 7 is a sectional view showing one embodiment of the reflection type liquid crystal display device of the present invention.

FIG. 8 is a diagram showing an operation principle of one embodiment of the reflection type liquid crystal display device of the present invention.

FIG. 9 is a process chart showing a manufacturing process of the reflective active matrix substrate of the present invention.

FIG. 10 is a sectional view of a reflective liquid crystal display device using the reflective active matrix substrate of the present invention.

FIG. 11 is a cross-sectional view showing one embodiment of a method for producing a reflector according to the present invention.

FIG. 12 is a sectional view showing one embodiment of the reflection type liquid crystal display device of the present invention.

FIG. 13 is a sectional view showing one embodiment of the reflection type liquid crystal display device of the present invention.

FIG. 14 is a sectional view showing one embodiment of the reflection type liquid crystal display device of the present invention.

[Explanation of symbols]

21, 61, 75, 128, 136, 147 Reflecting plate 22, 62 Light source 23, 26, 33, 63, 66, 121, 131, 14
DESCRIPTION OF SYMBOLS 1 Polarizing plate 24, 27, 36, 64, 67, 122 Quarter-wave plate 25, 65 Light receiver 31 Incident light 32 Outgoing light 34 Slow axis of polarizing plate 35 Fast axis of polarizing plate 37 Optical axis 51, 71 , 81, 95, 111, 123, 126,
132, 142, 145 Glass substrates 52, 113 Resist films 53, 114 Photomasks 54, 112, 115 Organic insulating films 55, 116 Reflective films 72, 97, 124, 133, 143 Transparent electrodes 73, 93, 98, 125, 134 , 144 alignment film 74, 99, 129, 135, 148 liquid crystal layer 96 color filter 88 reflective electrode 90 TFT (thin film transistor) 92 irregularity forming resin 96 a transmitting part 96 b light shielding layer 127, 146 transparent resin

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G02F 1/1335 520 G02F 1/13 101 G02F 1/1343

Claims (1)

(57) [Claims] A first substrate having an electrical insulation property and a light-transmitting property, and a transparent electrode formed on one side; and a first substrate and a liquid crystal layer interposed therebetween. A reflection type liquid crystal display comprising: a second substrate having electrical insulation provided with a light reflection member disposed to face and reflecting incident light; and a polarizing plate provided on the first substrate on a light incident side. apparatus of
A step of applying an organic insulating film on the liquid crystal layer side on the second substrate in the manufacturing method
Exposing and developing the organic insulating film to form a plurality of irregularities.
Forming a plurality of irregularities and heat-treating the plurality of irregularities to form smooth-shaped irregularities.
And removing the organic material along the smooth irregularities on the smooth irregularities.
Forming a Enmaku, and forming a light reflecting member on the organic insulating film, [2 Number] polarization degree V of the following formulas of the reflected light by the light reflecting member S ₀ , S ₁ , S ₂ , S ₃ : Stokes parameters of reflected light obtained by making circularly polarized light incident on the light reflecting member. S ₁ : horizontal linearly polarized light component, S ₂ : 45 ° linearly polarized light component, S ₃ : right circularly polarized light component, S ₀ : light intensity is selected to be at least 50% or more.
A method for manufacturing a reflective liquid crystal display device.