JPH06175126A - Reflection type liquid crystal display device and its production - Google Patents

Abstract

PURPOSE:To make bright display by obtaining scattered light having directivity. CONSTITUTION:An org. insulating film 42 is formed to cover gate bus wirings, source bus wirings and TFTs 40 formed on one substrate 31 of the reflection type liquid crystal display device 30. Projecting parts 42a which are convergent and are formed to a spherical shape at the fronts are formed in the regions of this org. insulating film 42 where reflection electrodes 38 are formed. These projecting parts 42a are so patterned that the average angle; thetaAV of inclination is within a 4 to 15 deg. range. The scattered light having the directivity is obtd. by deciding the average angle thetaAV of inclination is within the 4 to 15 deg. range and, therefore, the extremely bright display is realized.

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 for displaying by reflecting incident light and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, application of liquid crystal display devices to word processors, laptop personal computers, pocket televisions, etc. has been rapidly progressing. Among the liquid crystal display devices, a reflective liquid crystal display device that reflects light incident from the outside to perform display is particularly noteworthy because it does not require a backlight and thus consumes less power and can be thin and lightweight. ing.

Conventionally, a TN has been used for a reflective liquid crystal display device.
The (twisted nematic) method and the STN (super twisted nematic) method are used, but in these methods, 1/2 of the light intensity of natural light is not necessarily used for display due to the linear polarizer, and the display is There is a problem that it gets dark.

To solve such a problem, a display mode has been proposed in which natural light is effectively used without using a polarizing plate. An example of such a mode is the phase transition type guest-host method (DLWhite and GNTayl
or: J.Appl.Phys.45 4718 1974). In this display mode, the cholesteric / nematic phase transition phenomenon due to the electric field is used. A reflective multicolor display in which a micro color filter is further combined with this phase transition type guest-host system has been proposed (Tohru Ko
izumi and Tatsuo Uchida, Proceedins of the SID, Vol.
29,157,1988).

In order to obtain a brighter display in a display mode that does not require such a polarizing plate, it is necessary to increase the intensity of light scattered in a direction perpendicular to the display screen with respect to incident light from all angles. is there. For that purpose, it is necessary to control the surface state of the reflection plate to produce a reflection plate having optimum reflection characteristics. In the above-mentioned document, the surface of the substrate made of glass or the like is roughened with an abrasive, and the unevenness of the surface is controlled by changing the etching time with hydrofluoric acid, and a silver thin film is formed on the unevenness. A reflector is described. Further, Japanese Patent Application No. 3-230608 proposes a reflection plate for providing good reflection characteristics by providing irregularities on a portion having a reflection function.

[0006]

The shape of the unevenness formed by the conventional manufacturing method as described above cannot be said to be the optimum uneven shape, and a reflector having good reflection characteristics cannot be obtained. In addition, literature on the above-mentioned reflective multi-color display (Tohru Koizumi and Tatsuo Uchida, Proceedins
of the SID, Vol.29, 157, 1988), the reproducibility of the uneven shape is poor and the thin film transistor (hereinafter referred to as “TFT”) is used because it is roughened with an abrasive or etched with hydrofluoric acid. There is also a risk of damaging (abbreviated).

An object of the present invention is to solve the above problems and provide a reflection type liquid crystal display device provided with a reflection plate having better reflection characteristics and a manufacturing method thereof.

[0008]

According to the present invention, of a pair of translucent substrates which are opposed to each other with a liquid crystal layer interposed therebetween, a plurality of picture element electrodes and another A reflective film that reflects incident light from the substrate side and an alignment film are formed,
On the other hand, in a reflective liquid crystal display device in which a transparent common electrode and an alignment film are formed on almost the entire surface of the substrate on the liquid crystal layer side, the reflective surface of the reflective film is a smooth uneven surface. In addition, the reflective liquid crystal display device is characterized by satisfying a predetermined average tilt angle.

According to the present invention, the average tilt angle is 4 °.
It is characterized in that it is selected to be -15 °.

Further, the present invention is characterized in that the reflection film functions as a pixel electrode.

The present invention also provides, among the pair of translucent substrates,
On the other hand, an organic insulating film and a photoresist layer to be laminated thereon are formed on the surface of the substrate, and patterned to form a photoresist layer on a smooth uneven surface having a predetermined average inclination angle, and then subjected to an etching treatment to form an organic insulating film. The film is formed on a smooth uneven surface having the predetermined average inclination angle, a reflective film is formed on the uneven surface, and a plurality of pixel electrodes and an alignment film are further formed on the surface of the reflective film. Among the translucent substrates, a common electrode having a translucency and an alignment film are formed on almost the entire surface of the other substrate, and the pair of translucent substrates are attached so that the electrode forming surfaces face each other, and A method of manufacturing a reflection type liquid crystal display device, characterized in that liquid crystal is injected between the optical substrates.

The present invention also provides, among the pair of translucent substrates,
On the other hand, the surface of the substrate is coated with a photosensitive resin and patterned to form a smooth uneven surface having a predetermined average inclination angle, a reflective film is formed on the uneven surface, and a plurality of reflective films are formed on the surface of the reflective film. A pixel electrode and an alignment film are formed, and a common electrode having a light-transmitting property and an alignment film are formed over the entire surface of the other substrate of the pair of light-transmitting substrates. A method for manufacturing a reflection type liquid crystal display device, characterized in that the substrates are attached so that the electrode formation surfaces face each other, and liquid crystal is injected between the translucent substrates.

According to the present invention, the average tilt angle is 4 °.
It is characterized in that it is selected to be -15 °.

Further, the present invention is characterized in that the plurality of picture element electrodes have a function as a reflection film and are directly formed on the uneven surface.

[0015]

According to the present invention, the reflective liquid crystal display device has a pair of translucent substrates which are opposed to each other with a liquid crystal layer interposed therebetween, and the liquid crystal on one of the pair of translucent substrates. On the layer side surface, a plurality of pixel electrodes and a reflection film and an alignment film for reflecting incident light from the other substrate side are formed, and the reflection surface of the reflection film is a smooth uneven surface and has a predetermined average. It is formed so as to satisfy the inclination angle. In addition, a light-transmitting common electrode and an alignment film are formed on almost the entire surface of the other substrate on the liquid crystal layer side. The intensity of scattered light in the normal direction of the substrate surface can be increased by forming the reflecting surface of the reflecting film into a smooth uneven surface that satisfies a predetermined average inclination angle.

The average tilt angle of the reflecting film is preferably 4 ° to 15 °, which makes it possible to increase the directivity of scattered light, that is, the intensity of scattered light in the normal direction of the substrate surface. .

Furthermore, by causing the reflective film to function as a pixel electrode, it is possible to prevent display shift due to parallax.

According to the invention, an organic insulating film and a photoresist layer are laminated on the surface of one of the pair of translucent substrates, and the photoresist layer is smooth with a predetermined average inclination angle. It is formed on a rough surface. Then, an etching process is performed to form an organic insulating film on a smooth uneven surface having a predetermined average inclination angle. A reflective film is formed on the uneven surface, and a plurality of picture element electrodes and an alignment film are further formed on the reflective film. On the other surface of the other substrate, a light-transmitting common electrode and an alignment film are formed over almost the entire surface. Such a pair of translucent substrates are attached so that their electrode formation surfaces face each other, and liquid crystal is injected between the translucent substrates to manufacture a reflective liquid crystal display device.

Therefore, since the reflecting surface of the reflecting film is formed as a smooth uneven surface satisfying a predetermined average inclination angle, the intensity of scattered light in the normal direction of the substrate surface can be increased.

Further, according to the present invention, a photosensitive resin is applied to the surface of one of the pair of translucent substrates and patterned to form a smooth uneven surface having a predetermined average inclination angle. A reflective film is formed on the uneven surface,
Further, a plurality of picture element electrodes and an alignment film are formed thereon.
On the other surface of the other substrate, a light-transmitting common electrode and an alignment film are formed over almost the entire surface. Such a pair of translucent substrates are attached so that their electrode formation surfaces face each other, and liquid crystal is injected between the translucent substrates to manufacture a reflective liquid crystal display device.

Therefore, since the reflecting surface of the reflecting film is formed as a smooth uneven surface satisfying a predetermined average inclination angle, the intensity of scattered light in the normal direction of the substrate surface can be increased.

The smooth uneven surface is formed so that the average inclination angle is 4 ° to 15 °. Thereby, the intensity of scattered light in the normal direction of the substrate can be further increased.

Furthermore, the plurality of picture element electrodes have a function as a reflection film and are directly formed on the uneven surface. Therefore, it is possible to prevent a display shift caused by parallax.

[0024]

1 is a sectional view of a reflective liquid crystal display device 30 according to an embodiment of the present invention, and FIG. 2 is a plan view of a substrate 31 shown in FIG. A plurality of gate bus wirings 32 made of chromium, tantalum, or the like are provided in parallel with each other on an insulating substrate 31 made of glass or the like, and a gate electrode 33 is provided from the gate bus wirings 32 functioning as scanning lines. It is branched.

Silicon nitride (Si) is formed on the entire surface of the substrate 31 so as to cover the gate bus wiring and the gate electrode 33.
A gate insulating film 34 made of N _X ), silicon oxide (SiO _X ) or the like is formed. Amorphous silicon (hereinafter referred to as “a-Si”), polycrystalline silicon, CdSe is formed on the gate insulating film 34 above the gate electrode 33 in FIG.
A semiconductor layer 35 made of, for example, is formed. Contact electrodes 41 made of a-Si or the like are formed on both ends of the semiconductor layer 35 in the left-right direction in the plane of FIG. A source electrode 36 made of titanium, molybdenum, aluminum, or the like is superposed on one of the contact electrodes 41a at both ends, and titanium, molybdenum, aluminum, or the like is formed on the other contact electrode 41b similarly to the source electrode 36. A drain electrode 37 composed of is formed so as to overlap.

As shown in FIG. 2, the source electrode 36 is connected to the source bus line 39 which intersects the gate bus line 32 and functions as a signal line. Source bus wiring 39
Is also made of the same metal as the source electrode 36. The gate electrode 33, the gate insulating film 34, the semiconductor layer 35, the source electrode 36, and the drain electrode 37 form a TFT 40, and the TFT 40 has a function of a switching element.

Gate bus wiring 32, source bus wiring 39
An organic insulating film 42 is formed on the entire surface of the substrate 31 so as to cover the TFT 40. In the region on the organic insulating film 42 where the reflective electrode 38 is formed, a tapered convex portion 42a having a spherical tip is formed, and a contact hole 43 is formed in the drain electrode 37 portion. Has been formed. A reflective electrode 38 made of aluminum, silver, or the like is formed on a region where the convex portion 42a of the organic insulating film 42 is formed, the reflective electrode 38 is connected to the drain electrode 37 in the contact hole 43, and the alignment film 4 is formed thereon.
4 is formed.

With the above structure, the reflective electrode 38
Since the gate bus line 32 and the source bus line 39 can be overlapped with each other, the space between the reflective electrode 38 and the gate bus line 32 and the source bus line 39 can be eliminated to reduce the area of the reflective electrode 38. Can be large. When the area of the reflective electrode 38 is large, the aperture ratio of the display screen is large, and bright display is possible. At this time, if insulation failure becomes a problem in the portion where the reflective electrode 38 and the gate bus wiring 32 and the source bus wiring 39 overlap, the problem is solved by not forming the convex portion 42a in the overlapping portion. .

A complementary color filter 46 is provided on the substrate 45.
Is formed. The color filter 46 has a magenta or green filter 46 at a position facing the reflective electrode 38.
a is formed, and a black light shielding layer 46b is formed at a position not facing the reflective electrode 38. Color filter 4
An ITO (indium tin oxide) film is formed on the entire surface of 6
The transparent common electrode 47 is formed to a thickness of 00Å, and the alignment film 48 is formed by applying polyimide and then baking.

The substrates 31 and 45 are laminated so that the reflective electrode 38 and the filter 46a are opposed to each other, and a liquid crystal injection space is formed by screen-printing an adhesive sealant (not shown) containing a spacer of 7 μm. Are formed, and the liquid crystal 49 is injected by degassing in vacuum to complete the reflective liquid crystal display device 30. As the liquid crystal 49, a guest-host liquid crystal mixed with a black dye (Merck, trade name ZL12327) mixed with 4.5% of an optically active substance (Merck, trade name S811) was used.

FIG. 3 is a sectional view for explaining a general manufacturing method for manufacturing the reflection plate 29. As shown in FIG. 3B, an acrylic resin (Japan Synthetic Rubber) is provided on an insulating substrate 25 (Corning Co., Ltd., product name 7059) having a thickness of 1.1 mm and made of glass or the like shown in FIG. 3A. , Product name JSS
-7215) to 1200 r. p. The organic insulating film 26 is formed by spin coating at m for 20 seconds.

Subsequently, as shown in FIG. 3C, a photoresist 22 is applied on the organic insulating film 26, and as shown in FIG. 3D, circular through holes are regularly or irregularly arranged. The mask 23 is used to selectively irradiate light 24 to remove unnecessary photoresist portions, thereby forming columnar convex portions 22a as shown in FIG. 3 (e). Further, heat treatment is performed in a range of 120 ° C. to 250 ° C. with a hot plate, an oven, or the like in order to remove the corner of the tip portion of the convex portion 22a, and
As shown in (f), the desired average tilt angle (4 ° -15
) Is formed on the smooth uneven surface. After that, FIG.
As shown in (g), the organic insulating film 26 is etched using the convex portions 22a, and a desired average inclination angle (4 ° to 15 °) is obtained.
To form a convex portion 26a having the angle .degree.). Also, the convex portion 26a
In order to adjust the average inclination angle of the protrusions 26a after formation,
Further, the organic insulating film 26b may be applied.

Further, as shown in FIG. 3 (h), after forming the organic insulating film 26b, aluminum is vacuum-deposited to a thickness of 0.01 to 1.0 μm as shown in FIG. 3 (i). The metal thin film is formed to form the reflection film 27. Reflective film 2
In addition to aluminum, nickel, chromium, silver or the like may be used for 7. The reflector 29 is formed by the above steps. The reflecting surface 28 of the reflecting film 27 is formed on the uneven surface having the average inclination angle.

FIG. 4 shows the substrate 3 shown in FIGS. 1 and 2.
FIG. 5 is a process diagram for explaining the manufacturing method of No. 1, and FIG. 5 is a sectional view showing the process. In step s1, 30 is formed on the insulating substrate 31 made of glass or the like by the sputtering method.
A tantalum metal layer having a thickness of 00 Å is formed, and the metal layer is patterned by photolithography and etching to form a gate bus wiring 32 and a gate electrode 33.
To form. In step s2, the gate insulating film 34 made of silicon nitride having a thickness of 4000 Å is formed by the plasma CVD method.

In step s3, the thickness of the semiconductor layer 35 is 1
A 000 Å a-Si layer and a 400 Å thick n ⁺ -type a-Si layer to be the contact layer 41 are continuously formed in this order. The formed n ⁺ -type a-Si layer and a-Si layer are patterned to form the semiconductor 35 and the contact layer 4.
1 is formed. In step s4, a thickness of 2 is formed on the entire surface of the substrate 31.
000 Å molybdenum metal is formed by the sputtering method, and the molybdenum metal layer is patterned to form the source electrode 36, the drain electrode 37 and the source bus wiring 39, and the TFT 40 is completed. Figure 4 (a)
It is sectional drawing of the board | substrate 31 in which TFT40 was formed after the process to process s4 is complete | finished. Hereinafter, the reflective electrode is formed according to the method for manufacturing the reflective plate described above with reference to FIG.

In step s5, a polyimide resin having a thickness of 2 μm is formed on the entire surface of the substrate 31 on which the TFT 40 is formed.
The organic insulating film 42 is formed. In step s6, the contact hole 43 is formed in the organic insulating film 42 by using the photolithography method and the dry etching method. In step s7, a photoresist 50 is applied on the organic insulating film 42, and a convex portion 50a is patterned in the reflection electrode 38 formation region using a mask. Furthermore, in order to remove the corner of the convex portion 50a, 12
Heat treatment is performed in the range of 0 ° C to 250 ° C to form a smooth uneven surface having a desired average inclination angle (4 ° to 15 °). In this example, heat treatment was performed at 200 ° C. for 30 minutes. Figure 4
A sectional view of the substrate 31 after the steps up to step s7 is shown in (b).

In step s8, as shown in FIG. 4C, the organic insulating film 42 is etched in accordance with the photoresist 50 to form a convex portion 42a having a desired average inclination angle (4 ° to 15 °). . At this time, heat treatment is applied to the convex portion 5
Since the corner of 0a is formed and formed at a predetermined average inclination angle, the convex portion 42a also has an angle and is formed at the predetermined average inclination angle. Further, the contact hole 43 and the organic insulating film 42 on the TFT 40 are protected by the photoresist 50 and are not etched.

In step s9, an aluminum layer is formed on the entire surface of the organic insulating film 42 and then patterned to form a reflection electrode 38 on the convex portion 42a as shown in FIG. 4D.
To form. The reflective electrode 38 is connected to the drain electrode 37 of the TFT 40 via a contact hole 43 formed in the organic insulating film 42.

The shape of the convex portion 42a on the organic insulating film 42 is
It has been confirmed that it can be controlled by the shape of the mask, the thickness of the photoresist 50, and the dry etching time. In the above manufacturing process, the organic insulating film 4
The substrate 31 in which the average inclination angle of the convex portions 42a is 4 ° to 15 ° can be obtained by lengthening the dry etching time of 2 in FIG.

FIG. 6 is a diagram for explaining the average tilt angle. The inclination angle θ _AV of the convex portion 42a is a plane D including the straight line C connecting the vertex A and the point B having no inclination closest to the vertex A with respect to the convex portion 42a and the plane D including the points B in the other plural convex portions. It is the angle formed by and. In this embodiment, the inclination angle θ _AV is set to a value within a predetermined range to obtain scattered light having directivity.

FIG. 7 shows substrates 19 and 2 having a reflective film 13.
It is sectional drawing which shows the measuring method of the reflection characteristic of 0,21. Substrate 1 having reflective film 13 formed on organic insulating film 12
The glass substrate 15 is adhered onto 9, 20, 21 via the ultraviolet curable adhesive resin 14 to form the measuring device 10. In the reflection type liquid crystal display device 30 described above, since the refractive indexes of the substrate 45 and the liquid crystal 49 are both about 1.5, the refractive indexes of the ultraviolet curing adhesive resin 14 and the substrate 15 are about 1.5. ing. A photomultimeter 18 for measuring the intensity of light is arranged above the substrate 15. The photomultimeter 18 uses the reflection film 13 to reflect the incident light 16 incident on the surface of the substrate 15 at the incident angle θ.
In order to detect the scattered light 17 reflected in the normal direction of 5,
It is fixed in the direction normal to the substrate 15.

The reflection characteristic of the reflective film 13 is obtained by changing the incident angle θ of the incident light 16 incident on the measuring device 10 and measuring the scattered light 17 by the reflective film 13. It has been confirmed that this measurement result is similar to the reflection characteristic at the boundary between the reflective electrode 38 and the liquid crystal 49 layer in the reflective liquid crystal display device 30.

FIGS. 8, 9 and 10 are graphs showing the reflection characteristics of the substrates 19, 20, and 21 having the above-mentioned reflection film 13, respectively, and the average inclination angle θ _AV of the uneven surface is 8 ° and 3 respectively. The results are measured at 18 °. Board 1
The reflection characteristic of 9 is shown by curve 1 in FIG. 8, the reflection characteristic of the substrate 20 is shown by curve 2 in FIG. 9, and the reflection characteristic of the substrate 21 is shown by curve 3 in FIG.

In FIGS. 8 to 10, the reflection intensity of the light incident at the incident angle θ is represented as the distance from the origin 0 in the direction of the angle θ with respect to the straight line of θ = 0 °. Further, in FIGS. 8 to 10, a curved line 4 indicated by a broken line shows the reflection characteristic measured on the standard white plate (magnesium oxide).

According to the curve 1 in FIG. 8, the reflectance at ± 30 ° evaluated as the viewing angle was 120% of the reflectance of the standard white plate. Further, the reflectance at ± 40 ° or more is suppressed to several percent to several tens of percent, which is a good reflection characteristic with directivity.

Next, in the curve 2 in FIG. 9, the directivity is too strong, and the surface becomes a specular reflection. With such a concavo-convex shape, white light due to scattering cannot be obtained, and the metallic color of aluminum of the reflection film 13 used in this example appears, so that bright and clear white display cannot be realized. Further, in the curve 3 in FIG. 10, the reflected light, which is scattered by the reflection film 13 because the degree of scattering is too large, passes through the liquid crystal layer and the glass substrate, and a large amount of light is emitted in a direction other than the viewing angle. The reflected light does not collect in the corner. Therefore, bright display cannot be performed and clear white display cannot be performed.

FIG. 11 shows the average inclination angle θ _AV of the uneven surface and ±
It is a graph which shows the relationship with the reflected light intensity of a reflecting plate in 30 degrees. Average tilt angle θ _AV (= 4 ° ~
15 °) has a reflectance of 8 with respect to a standard white plate.
It was 0% or more, and it was confirmed that it was extremely bright. By appropriately selecting the type and film thickness of the photosensitive resin and the heat treatment temperature, the average inclination angle θ _AV of the uneven surface is 4 ° to 15 °.
It is possible to have an optimal angle of °.

In the reflective liquid crystal display device of this embodiment, since the surface of the reflective active matrix substrate 31 on which the reflective electrodes 38 are formed is disposed on the liquid crystal layer side, parallax is eliminated and a good display screen is obtained. To be Further, in this embodiment, since the reflective electrode 38 of the reflective active matrix substrate 31 is arranged on the liquid crystal layer side, that is, at a position substantially adjacent to the liquid crystal layer, the height of the convex portion 42a is the liquid crystal layer thickness. The average tilt angle of 4 ° to 15 °, which is selected smaller than the above, is a moderate angle that does not disturb the alignment of the liquid crystal molecules.

Further, although the patterning of the organic insulating film 42 is performed by the dry etching method in this embodiment, when the organic insulating film 42 is a polyimide resin, it may be patterned by the wet etching method using an alkaline solution. Further, the polyimide resin is used as the organic insulating film 42,
Other organic materials such as acrylic resin can also be used. Further, although the glass substrate is used as the substrate 31 in the present embodiment, an opaque substrate such as a silicon substrate exhibits the same effect, and in this case, there is an advantage that the circuit can be integrated on the substrate.

Although the phase transition type guest-host mode is taken as the display mode in the above-mentioned embodiments, the present invention is not limited to this, and other light absorption modes such as a two-layer guest-host mode and polymer dispersion may be used. The present invention can be applied to a reflective active matrix substrate according to the present invention and a panel structure thereof, such as a light-scattering display mode such as a type LCD and a birefringence display mode used in a ferroelectric LCD. Although the case where the TFT is used as the switching element has been described, for example, MIM (Metal-Insulator-
It can also be applied to an active matrix substrate using a metal) element, a diode, a varistor, or the like.

FIG. 12 is a process chart for explaining another embodiment of the present invention. A substrate 71 made of glass or the like and having a thickness of 1.1 mm shown in FIG.
59) On the surface, as shown in FIG. 12B, a photosensitive resin (Tokyo Ohka, trade name OFPR-800) was applied for 1500 r.p.
p. of 20 μm for 20 seconds and 1.7 μm film 72
To form. As shown in FIG. 12C, light 74 is emitted by using a mask 73 in which circular through holes are regularly or irregularly arranged.
Are selectively irradiated to remove unnecessary portions to form convex portions 72a as shown in FIG.

Further, in order to remove the corners of the convex portion 72a, the convex portion 7
2a on a hot plate or oven at 120 ° C-25
Heat treatment is performed in the range of 0 ° C. to form a smooth convex portion 72a having a desired angle (4 ° to 15 °) as shown in FIG. Further, as shown in FIG.
After forming the organic insulating film 75, aluminum is vacuum-deposited to form a metal thin film 76 having a thickness of 0.01 to 1.0 μm as shown in FIG. As the metal thin film 76, nickel, chromium, silver, or the like may be used as in the first embodiment. The reflector is formed by the above steps. This reflector also has an average inclination angle θ _AV of the convex portion 72a of 4 ° to 15 °.
The effect similar to that of the first embodiment can be obtained by adjusting to.

[0053]

As described above, according to the present invention, a reflective film having a concave-convex surface is formed on the liquid crystal layer side surface of one of a pair of translucent substrates constituting a reflective liquid crystal display device, and the average inclination angle thereof is formed. Are formed to be selected from 4 ° to 15 °. Therefore, scattered light having directivity in the direction normal to the display surface can be obtained, and extremely bright white display can be performed, and clear color display can be performed by disposing the color filter.

[Brief description of drawings]

FIG. 1 is a sectional view of a reflective liquid crystal display device 30 according to an embodiment of the present invention.

FIG. 2 is a plan view of a substrate 31 shown in FIG.

FIG. 3 is a cross-sectional view showing a general process for forming a reflection plate 29.

4A to 4C are process diagrams illustrating a method of manufacturing the substrate 31 shown in FIGS.

5A to 5D are cross-sectional views of steps showing a method for manufacturing the substrate 31 shown in FIGS.

FIG. 6 is a diagram for explaining an average tilt angle.

FIG. 7 is a cross-sectional view showing a method for measuring the reflection characteristic of a reflection plate.

FIG. 8 is a graph showing reflection characteristics of a substrate 19 having a reflection film 13 with an average inclination angle θ _AV = 8 °.

FIG. 9 is a graph showing the reflection characteristics of the substrate 20 having the reflection film 13 with the average inclination angle θ _AV = 3 °.

FIG. 10 is a graph showing the reflection characteristics of the substrate 21 having the reflection film 13 having an average inclination angle θ _AV = 18 °.

FIG. 11 is a graph showing the relationship between the average tilt angle θ _AV and the reflected light intensity at ± 30 °.

FIG. 12 is a sectional view illustrating another embodiment of the present invention.

[Explanation of symbols]

11, 15, 19, 20, 21, 31, 45, 52, 7
1 Substrate 12, 26, 26a, 42, 42a, 72, 72a Organic Insulating Film 13, 38, 78 Reflective Electrode 27, 76 Metal Thin Film 29 Reflector 30 Reflective Liquid Crystal Display Device 49 Liquid Crystal Layer θ _AV Average Inclination Angle θ Normal Angle to direction

Claims (7)

[Claims] 1. A pair of translucent substrates which are opposed to each other with a liquid crystal layer interposed therebetween, wherein a liquid crystal layer side surface of one substrate reflects a plurality of pixel electrodes and incident light from the other substrate side. A reflective liquid crystal display device in which a reflective film and an alignment film are formed, and a common electrode having a light-transmitting property and an alignment film are formed on almost the entire surface of the other substrate on the liquid crystal layer side. The reflective liquid crystal display device, wherein the reflective surface of the film is a smooth uneven surface and satisfies a predetermined average tilt angle. 2. The reflective liquid crystal display device according to claim 1, wherein the average tilt angle is selected from 4 ° to 15 °. 3. The reflective liquid crystal display device according to claim 1, wherein the reflective film functions as a pixel electrode. 4. An organic insulating film and a photoresist layer to be laminated thereon are formed on the surface of one of the pair of translucent substrates, and patterned to form a smooth photoresist layer having a predetermined average inclination angle. Formed on a rough surface and subjected to etching to form an organic insulating film on the smooth uneven surface having the predetermined average inclination angle, a reflective film is formed on the uneven surface, and a plurality of films are formed on the surface of the reflective film. Forming a pixel electrode and an alignment film, and forming a transparent common electrode and an alignment film over substantially the entire surface of the other substrate of the pair of light-transmitting substrates. A method for manufacturing a reflection type liquid crystal display device, which comprises sticking a transparent substrate so that electrode forming surfaces face each other, and injecting liquid crystal between the translucent substrates. 5. A photosensitive resin is applied to the surface of one of the pair of translucent substrates, and patterning is performed to form a smooth uneven surface having a predetermined average inclination angle. A reflective film is formed, a plurality of picture element electrodes and an alignment film are further formed on the surface of the reflective film, and a common electrode having a translucent property over substantially the entire surface of the other substrate of the pair of translucent substrates. And an alignment film are formed, the pair of translucent substrates are attached so that the electrode formation surfaces face each other, and liquid crystal is injected between the translucent substrates. 6. The method of manufacturing a reflective liquid crystal display device according to claim 4, wherein the average tilt angle is selected to be 4 ° to 15 °. 7. The method of manufacturing a reflective liquid crystal display device according to claim 4, wherein the plurality of pixel electrodes have a function as a reflective film and are directly formed on the uneven surface. .