JPH0895071A - Reflection type liquid crystal display device - Google Patents

Abstract

PURPOSE: To provide a reflection type liquid crystal display device which is bright and does not deteriorate display grade due to peeling of a reflection electrode. CONSTITUTION: A plurality of gate bus wirings 52 and source bus wirings 53 are formed on the surface on the liquid crystal layer side of an insulating substrate 78 constituting one substrate 51 of a pair of substrates oppositely arranged through a liquid crystal layer, so that they are squarely crossed with each other while holding insulation. A reflection electrode 54 is formed in the rectangular area formed by crossing the wirings 52, 53 with each other. The reflection electrode 54 and the wirings 52, 53 are connected together through a TFT element 55. The reflection electrode 54 is provided with recessed and projecting surface, and the ratio of the territory removing recessed parts 60a, 60b to the marginal part area is selected in the range of 60%-100% in the marginal part 54a of the reflection electrode 54.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a portable information terminal device,
The present invention relates to a reflection type liquid crystal display device which is suitably used as a display means of a portable word processor, a personal computer or the like and which displays by reflecting incident light from the outside.

[0002]

2. Description of the Related Art Since a liquid crystal display device is relatively thin, lightweight and has low power consumption, it has been widely used as a display means for personal computers, word processors, electronic notebooks and other information terminal devices, and portable televisions. It is used.

In a liquid crystal display device for displaying in black and white,
TN (Twisted Nematic) type liquid crystal display device is used as an electronic device such as an electronic desk calculator and a clock that displays a relatively small amount of information, and STN (Super Twisted) is used as an electronic device such as a word processor that displays a relatively large amount of information. A nematic type liquid crystal display device is used. The TN type and STN type liquid crystal display devices require two polarizing plates, and the utilization efficiency of light incident from the outside is 30% or less. Therefore, when it is used as a reflection type liquid crystal display device provided with a reflection plate, a display image becomes dark. A backlight may be provided to make the displayed image brighter, but this causes inconveniences such as an increase in power consumption and an increase in weight, which is not suitable for a portable electronic device.

In a liquid crystal display device for color display, a liquid crystal display device in which a color filter is combined with the TN type and STN type liquid crystal display devices is used. Such a liquid crystal display device for color display realizes color display by color mixing. Even when realizing color display, since two polarizing plates are used as in the case of performing monochrome display, the utilization efficiency of incident light is low. Also,
In order to realize color display, three pixels of red, green and blue are used.
Since the light is divided into colors, the light utilization efficiency is further reduced by the pixel division. Furthermore, in an actual display panel, the aperture ratio of the pixel, that is, the ratio of the region that actually contributes to the display in the pixel region of one unit is also related to the light utilization efficiency, and when the aperture ratio becomes smaller, the light utilization efficiency becomes smaller. Also decreases. Although the pixel area becomes smaller when the display is made finer, there is a limit to the reduction of the area that does not contribute to the display, for example, the area required for the switching element or the wiring that supplies the voltage for the display. Get smaller. For this reason, in a liquid crystal display device that performs color display, the display image becomes darker. For example, the utilization efficiency of light is several percent. Therefore, a backlight is required, which hinders low power consumption and weight reduction.

To solve such problems, the efficiency of light utilization is
Investigations are being made to improve it. For example, liquid crystal
Mixing a dichroic dye in the layer and aligning the liquid crystal molecules
Having a Lull structure, that is, a white tailor type
By setting the guest / host mode,
A bright, high-contrast display image is obtained.
, D.L.White and G.N.Taylor; J.Appl.Phys.
45No. 11 4718 (1974) "
It According to this method, along the liquid crystal molecules that are twisted and aligned,
The dichroic dye also twists and aligns and enters such a liquid crystal layer.
The emitted light is polarized by the dichroic dye regardless of the direction of polarization.
Is absorbed. This allows, for example, a black and white display.
Black display can be realized. On the other hand, when applying a voltage, the electric field
Liquid crystal molecules and dichroic dye are oriented in the opposite direction, and incident light is transmitted.
To do. As a result, white display can be realized.

Further, for example, the method of using only one polarizing plate is "18th Liquid Crystal Conference 3D-110 (1992)".
Have been proposed in. According to this method, the liquid crystal display device has a structure of polarizing plate / liquid crystal layer / reflecting plate or polarizing plate / retardation plate / liquid crystal layer / reflecting plate, and display is performed by a phase change of light incident on the liquid crystal layer. Done. Since only one polarizing plate is used, a relatively bright display image can be obtained.

With these two methods, it is possible to improve the light utilization efficiency of 30% or less to about 50%. Further, it has been proposed to improve the aperture ratio of pixels, for example. This is disclosed, for example, in Japanese Patent Application Laid-Open No. 6-75238 by the present applicants.

FIG. 21 shows one substrate 3 of the reflection type liquid crystal display device 30 disclosed in Japanese Patent Laid-Open No. 6-75238.
1 is a plan view of FIG. 1, and FIG. 22 is a cross-sectional view of the reflective liquid crystal display device 30. A plurality of gate bus wirings 32 made of chromium, tantalum, or the like are provided in parallel with each other on one substrate 31 made of glass or the like and having an insulating property, and a gate electrode 33 branches from the gate bus wiring 32. The gate bus line 32 functions as a scanning line.

Gate bus wiring 32 and gate electrode 33
To cover the entire surface of the substrate 31 with silicon nitride (Si
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-S”) is formed on the gate insulating film 34 above the gate electrode 33.
i ”. ), Polycrystalline silicon, and a semiconductor layer 35 made of CdSe or the like. Contact electrodes 41 made of a-Si or the like are formed on both ends of the semiconductor layer 35. A source electrode 36 made of titanium, molybdenum, aluminum, or the like is superposed on one contact electrode 41, and a drain electrode made of titanium, molybdenum, aluminum, or the like is formed on the other contact electrode 41, like the source electrode 36. 37 is formed in an overlapping manner.

As shown in FIG. 21, the source electrode 36 has
A source bus line 39 that intersects with the gate insulating film 34 is connected to the gate bus line 32. The source bus line 39 functions as a signal line. The source bus line 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 thin film transistor (hereinafter referred to as “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. Reflective electrode 3 of organic insulating film 42
In a region where 8 is formed, a convex portion 42a having a height H and having a tapered tip end formed in a spherical shape is formed, and a predetermined portion on the drain electrode 37 of the organic insulating film 42 is formed. A contact hole 43 is formed. In order to reduce the problems in the method of forming the organic insulating film 42, the process of forming the contact holes 43 in the organic insulating film 42, and the variation in the thickness of the liquid crystal layer when the liquid crystal display device 30 is formed, the height H of the convex portion 42a is reduced. Is preferably 10 μm or less. Generally, the thickness of the liquid crystal layer is 10 μm or less. 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, and the reflective electrode 38 is connected to the drain electrode 37 through a contact hole 43. Further, an alignment film 44 is formed on it.

The color filter 4 is provided on the other substrate 45.
6 are formed. In the color filter 46, a magenta or green filter 46a is formed in a region facing the reflective electrode 38 of the substrate 31, and a black filter 46b is formed in a region not facing the reflective electrode 38. ITO (Indium Tin Oxide) is formed on the entire surface of the color filter 46.
A transparent electrode 47 made of, for example, is formed, and an alignment film 48 is further formed thereon.

The two substrates 31 and 45 are the reflection electrodes 3
8 and the filter 46a are bonded so as to face each other so as to match each other, and liquid crystal is injected between the substrates to form a liquid crystal layer 49. In this way, the reflective liquid crystal display device 30 is completed.

FIG. 23 is a plan view of a substrate 12 having TFTs 11 used in the active matrix system disclosed in Japanese Patent Laid-Open No. 6-75238 as a prior art, and FIG. 24 is a sectional plane X28- shown in FIG. X2
FIG. 8 is a cross-sectional view seen from 8. A plurality of gate bus wirings 13 made of chromium, tantalum, or the like are provided in parallel with each other on a substrate 12 having an insulating property such as glass, and gate electrodes 14 are branched from the gate bus wirings 13. The gate bus line 13 functions as a scanning line.

A gate insulating film 15 made of silicon nitride, silicon oxide or the like is formed on the entire surface of the substrate 12 so as to cover the gate electrode 14. A semiconductor layer 16 made of a-Si or the like is formed on the gate insulating film 15 above the gate electrode 14. At both ends of the semiconductor layer 16, a
A contact layer 17 made of —Si or the like is formed. A source electrode 18 is superposed on one contact layer 17, and a drain electrode 19 is superposed on the other contact layer 17. For the source electrode 18,
The source bus line 23, which functions as a signal line, intersects the gate bus line 13 and the gate insulating film 15 described above. The gate electrode 14, the gate insulating film 15, the semiconductor layer 16, the contact layer 17, the source electrode 18, and the drain electrode 19 form the TFT 11.

Further, an organic insulating film 20 having a plurality of convex portions 20a thereon and having a contact hole 21 on the drain electrode 19 is formed. A reflective electrode 22 is formed on the organic insulating film 20, and the reflective electrode 22 is connected to the drain electrode 19 via a contact hole 21. An alignment film is further formed on the reflective electrode 22,
Similar to the one substrate 31 as described above, it is bonded to the other substrate, and liquid crystal is injected between the substrates.

In the examples shown in FIGS. 21 to 24, since the reflective electrodes 38 and 22 are formed on the organic insulating films 42 and 20, one of the gate bus wirings 32 and 13 and the source bus wirings 39 and 23 is formed. It becomes possible to superimpose on the part. Therefore, the areas of the reflective electrodes 38 and 22 are increased, the aperture ratio is improved, and the light utilization efficiency is improved, so that a bright display image can be obtained. Further, in this method, since the reflective electrodes 38 and 22 made of a material having reflectivity are formed as the pixel electrodes and the reflective electrodes 38 and 22 are used as the reflectors, the opposite side of the substrates 31 and 12 from the liquid crystal layer. Parallax is reduced as compared with a reflection type liquid crystal display device in which a reflection plate is provided on the. By combining the liquid crystal display device having such a structure with the above-mentioned white teller type guest-host mode, a brighter reflection type liquid crystal display device can be realized.

[0018]

21 to 24, the utilization efficiency of light is improved and a bright display image can be obtained. However, the unevenness as described above causes the following problems. Inconvenience occurs. That is, the convex portions 42 a, 2 are formed on the surfaces of the organic insulating films 42, 20.
0a is formed, and the reflective electrodes 38 and 22 are provided on the organic insulating films 42 and 20 having the convex portions 42a and 20a.

The reflective electrodes 38 and 22 are first formed in the reflective electrode 3
It is formed by forming a metal film to be 8, 22 on the entire surface and then patterning it into a predetermined shape. An etching method is used for this pattern formation. At the time of etching, an unnecessary portion of the metal film is dissolved and removed by the etching liquid. At this time, the etching liquid permeates between the metal film to be left as the reflective electrodes 38 and 22 and the organic insulating films 42 and 20. . The penetration of the etching solution is more remarkable as the number of interfaces between the metal film and the organic insulating films 42 and 20 is larger at the edge portion of the metal film to be left, and by providing the convex portions 42a and 20a as described above, Apparently, the number of interfaces increases, and the penetration of the etching solution becomes remarkable. Although the metal film is formed by, for example, a sputtering method, the penetration of the etching solution becomes remarkable when the coverage of the metal film is poor.

When the etching solution thus permeates, the formed reflective electrodes 38 and 22 are separated from the edge portions thereof. The picture element from which the reflective electrodes 38 and 22 are peeled off becomes a defective picture element, and the display quality is significantly deteriorated. Also,
Since the peeled reflective electrodes 38 and 22 are present in the liquid crystal layer, this may cause a short circuit between the other reflective electrodes 38 and 22 and the transparent electrode facing the reflective electrodes 38 and 22.

In the examples shown in FIGS. 21 and 22, in order to avoid a short circuit between the reflective electrode 38 and the gate and source bus wirings 32, 39, the surface of the organic insulating film 42 on the wirings 32, 39 is covered. Does not provide the convex portion 42a, but does not define a region in which the convex portion 42a for preventing peeling as described above is not provided.

An object of the present invention is to provide a reflective liquid crystal display device which is bright and which does not deteriorate the display quality due to peeling of the reflective electrode.

[0023]

According to the present invention, a liquid crystal layer side surface of one of a pair of substrates, which are opposed to each other with a liquid crystal layer interposed therebetween and at least one of which has a light-transmitting property, comprises:
In a reflective liquid crystal display device having a light-transmitting electrode for reflecting incident light from the other substrate side, and having a light-transmitting electrode on the liquid crystal layer side surface of the other substrate, the reflection electrode is uneven. In the peripheral portion of the reflective electrode, the ratio of the region excluding the recesses or protrusions of the uneven surface to the peripheral region is selected in the range of 60% to 100%. And a reflective liquid crystal display device.
Further, according to the present invention, a liquid crystal layer side surface of one substrate of a pair of substrates, which are opposed to each other with a liquid crystal layer interposed therebetween and at least one of which has a light transmitting property, is provided from a side of the other substrate having a light transmitting property. A plurality of reflective electrodes which are display picture elements for reflecting incident light, a drawing electrode supplied with a display voltage applied to each reflecting electrode, and a voltage from the drawing electrode to the plurality of reflecting electrodes. In a reflective liquid crystal display device having a plurality of switching elements for individually supplying / cutting off, and a liquid crystal layer side surface of the other substrate having a translucent common electrode covering substantially the entire liquid crystal layer side surface. The reflective electrode has a concave-convex surface, and in the peripheral portion of the reflective electrode, the ratio of the region excluding the concave portion or the convex portion of the concave-convex surface to the peripheral region is 60% or more and 100% or less. Anti-characterized by being selected in range It is the type liquid crystal display device. In the present invention, the reflective electrode has a rectangular or substantially rectangular shape, and one of a direction parallel to the direction of the peripheral edge of the reflective electrode with respect to a length in a direction parallel to the opposite ends of the reflective electrode. The width ratio is selected in the range of 0.3% to 10%. Further, the concave portions or the convex portions in one reflective electrode of the present invention are characterized by being irregularly arranged. Furthermore, the recess or protrusion of the present invention is 1
It is characterized by being formed of two or more shapes having different kinds or sizes. Further, the arrangement pattern of the recesses or protrusions of the present invention is characterized in that it is selected in each reflection electrode. Furthermore, the arrangement pattern of the recesses or protrusions of the present invention is characterized in that they are selected so as to be mutually inverted between adjacent reflective electrodes. Further, the reflective electrode and the routing electrode of the present invention are characterized in that they are formed on the surface of one substrate on the liquid crystal layer side with a space therebetween that maintains their insulating properties.

[0024]

According to the present invention, the reflection type liquid crystal display device is constructed by arranging a pair of substrates, at least one of which has a light-transmitting property, facing each other with a liquid crystal layer interposed therebetween. The liquid crystal layer side surface of the substrate has a reflective electrode, while the liquid crystal layer side surface of the substrate has a translucent electrode. A portion where the reflective electrode and the strip-shaped electrode overlap is a display picture element, and light incident from the other transparent substrate side is reflected by the reflective electrode.

According to the invention, the reflective liquid crystal display device is constructed by arranging a pair of substrates, at least one of which has a light-transmitting property, facing each other with a liquid crystal layer interposed therebetween. The liquid crystal layer side surface of the one substrate has a plurality of reflection electrodes, a routing electrode and a plurality of switching elements, and the liquid crystal layer side surface of the other substrate has a common electrode.

The reflective electrode is a display picture element that reflects the incident light from the other substrate side having a light-transmitting property, and the routing electrode includes
The voltage for display applied to each reflective electrode is supplied,
The voltage is supplied / interrupted to / from the reflective electrodes by a switching element individually provided for the plurality of reflective electrodes. The common electrode covers almost the entire surface of the other substrate on the liquid crystal layer side and has a light-transmitting property.

In such a reflective liquid crystal display device,
The reflective electrode has an uneven surface, and in the peripheral portion thereof, that is, in an area having a predetermined length inward from the peripheral edge of the reflective electrode surface, an area excluding a recess or a convex portion with respect to the peripheral area. The proportion occupied by is selected from the range of 60% to 100%. The above ratio of 100% means that there are no recesses or protrusions in the peripheral portion.
In order to make the surface of the reflective electrode uneven, the surface on which the reflective electrode is to be formed is made uneven, and a metal film to be the reflective electrode is formed on the entire surface of the surface, and then the metal film is patterned. Thereby forming a reflective electrode. Etching is used to form the pattern of the metal film, and the unnecessary metal film is dissolved and removed.

In the reflective liquid crystal display device, the peripheral portion of the reflective electrode has relatively few or no recesses or protrusions, and therefore corresponds to the peripheral portion of the reflective electrode on the surface where the reflective electrode is to be formed. There are also relatively few or no recesses or protrusions formed in the part. Therefore, in the edge portion of the metal film remaining as the reflective electrode, the interface between the surface on which the reflective electrode is to be formed and the metal film becomes relatively small, and an etching solution is used during etching for patterning the metal film. The amount of permeation from the interface between the two becomes smaller.

Therefore, peeling from the edge portion of the reflective electrode is prevented, and the generation of defective picture elements is reduced. Also,
The peeled reflective electrode also prevents a short circuit from occurring between the other reflective electrode and the strip electrode or the common electrode facing the reflective electrode. Further, the reflective electrode functions as a reflective plate, which reduces parallax as compared with a reflective liquid crystal display device in which the reflective plate is provided on the side opposite to the liquid crystal layer side of the one substrate.

It was confirmed that peeling of the edge portion of the reflective electrode did not occur by setting the ratio of the region excluding the recess or the convex portion in the peripheral portion of the reflective electrode within the range of 60% or more and 100% or less. .

Further, according to the invention, the reflective electrode has a rectangular shape or a substantially rectangular shape, and a direction parallel to the direction of the peripheral portion of the reflective electrode with respect to a length of the reflective electrode in a direction parallel to the opposite ends. The ratio of one width is 0.3% or more 10
% Or less. The above-described recesses or protrusions are formed on the peripheral portion selected to have such a size.

Further, according to the present invention, the recesses or protrusions in one reflective electrode are arranged irregularly. Also preferably, the recesses or protrusions are formed of one type or two or more types having different sizes. Further, preferably, the arrangement pattern of the recesses or the protrusions is the same in each reflective electrode. Further, preferably, the arrangement patterns of the recesses or the protrusions are mutually inverted between adjacent reflective electrodes. Since all of them have the same reflection characteristic in any picture element, it is possible to obtain a uniform and high-contrast bright display image.

Further, according to the present invention, the reflective electrode and the lead-out electrode are formed on the liquid crystal layer side surface of the one substrate at an interval such that they maintain insulating properties. Thus, even when the reflective electrode and the routing electrode are formed, by making the reflective electrode surface uneven as described above,
A reflective liquid crystal display device that is relatively bright and has excellent display quality without peeling of the reflective electrode can be produced.

[0034]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows one substrate 5 of a reflection type liquid crystal display device 61 of an active matrix type which is an embodiment of the present invention.
It is a top view which expands and shows 1. Reflective liquid crystal display device 6
1 is configured by interposing a liquid crystal layer between a pair of substrates 51 and 71, at least one of which has translucency.

A plurality of gate bus lines 52 are provided in parallel with each other on an insulating substrate 78 made of, for example, glass, which constitutes one of the pair of substrates 51 and 71. A gate electrode 56 branches off from the gate bus line 52. Further, a plurality of source bus wirings 53 are provided so as to maintain insulation from the plurality of gate bus wirings 52 and in directions orthogonal to each other. A source electrode 57 branches off from the source bus line 53. A reflective electrode 54 is formed in a rectangular region on the substrate 51, which is formed by intersecting the plurality of gate bus lines 52 and the plurality of source bus lines 53. The reflective electrode 54 includes a gate bus line 52 and a source bus line 53.
Are provided at intervals W1 to W4 in order to maintain insulation between them.

The reflective electrode 54 and the gate bus wiring 52
The source bus line 53 and the source bus line 53 are connected via a TFT element 55 which is a switching element. TFT element 55
Includes a gate electrode 56 and a source electrode 57, and a drain electrode 58 connected to the reflective electrode 54. The drain electrode 58 and the reflective electrode 54 are connected by a contact hole 59 as described later.

A plurality of recesses 60a and 60b are provided on the surface of the reflective electrode 54, so that the surface is uneven. Although the plurality of recesses 60a and 60b are formed on almost the entire surface of the reflection electrode 54, the recesses 60a and 60b are provided in the peripheral portion 54a of the reflection electrode 54 shown by hatching in FIG. To be That is, the recess 60 with respect to the entire area of the peripheral portion 54a.
The ratio of the area excluding a and 60b is 60% or more 100
% Or less. What is shown is 100%
When selecting, that is, the recess 60 in the peripheral portion 54a.
This is the case where a and 60b were not formed at all. The peripheral portion 54a is a region having a predetermined length inward from the peripheral edge of the surface of the reflective electrode 54, and in the present embodiment, the predetermined length is represented by A2 and B2.

Further, in the present embodiment, a plurality of recesses 60a, 6
0b are randomly arranged in one reflective electrode 54,
And the plurality of recesses are two types of recesses 60a having different sizes,
It is composed of 60b. It should be noted that the plurality of recesses may be of one type, and that it is also within the scope of the present invention that the recesses are formed of three or more shapes having different sizes.

Further, the depth H of the recesses 60a and 60b is preferably 10 μm or less. Generally, the thickness of the liquid crystal layer is 10 μm or less, and the variation of the liquid crystal layer thickness can be reduced by selecting the depth H as described above. In this embodiment, the sizes of the recesses 60a and 60b are such that the maximum diameters D1 and D2 of the sectional shape are 10 μm and 5 μm, respectively.
m and the depth H was 0.6 μm.

FIG. 2 is a sectional view showing the reflection type liquid crystal display device 61. A method of manufacturing the reflective liquid crystal display device 61 will be described with reference to FIG. For example, the gate bus wiring 52 and the gate electrode 56 are formed on the insulating substrate 78 made of glass or the like, which is manufactured by Corning and has a trade name # 7059. This is, for example, an insulating substrate 78.
A Ta film having a thickness of 3000 Å is formed on the entire surface of the film by sputtering, and the Ta film is patterned by photolithography and etching.

Next, a gate insulating film 62 is formed so as to cover the gate bus line 52 and the gate electrode 56. This is, for example, plasma CVD (Chemical Vapor Deposit).
Ion) method to form a 4000 N thick SiN _x film. In addition, the gate bus wiring 52
Also, the gate electrode 56 can be formed by anodizing to form a Ta ₂ O ₅ film. In this embodiment, the SiN _x film is further formed by the plasma CVD method.
00Å thick a-Si layer and 400Å thick n ⁺
The mold a-Si layer was continuously formed in this order. the a-Si layer and the n ⁺ -type a-Si layer are simultaneously patterned,
The semiconductor layer 63 is formed by the a-Si layer, and the contact layers 64, 65 are formed by the n ⁺ -type a-Si layer.

Then, the entire surface of the insulating substrate 78 is covered with the formed member by a sputtering method at 2000 Å.
A Mo film having a thickness of 1 is formed, and the Mo film is patterned to form the source bus line 53, the source electrode 57, and the drain electrode 58. In this way
The TFT element 55 is created.

Insulating substrate 7 on which TFT element 55 is formed
An organic insulating film 66 having an uneven surface is formed on the entire surface of 8 by the method described later.
The reflective electrode 54 is formed thereon, and the surface of the reflective electrode 54 is also uneven due to the uneven surface of the organic insulating film 66. Therefore, recesses corresponding to the recesses 60a and 60b of the surface of the reflective electrode 54 as described above are formed in the region of the organic insulating film 66 where the reflective electrode 54 is to be formed.
Further, the contact hole 5 for connecting the reflective electrode 54 to the drain electrode 58 is formed in a predetermined region of the organic insulating film 66.
9 are provided. An alignment film 67 is formed on the organic insulating film 66 having the reflective electrode 54 formed thereon so as to cover the reflective electrode 54. In this way, the one substrate 51 is prepared.

A color filter 72 is formed on an insulating substrate 79 made of glass, for example, like the insulating substrate 78. The color filter 72 is, for example, a cyan filter 72a provided corresponding to each picture element.
And a red filter 72b. Color filter 7
A common electrode 73 having a thickness of 1000 Å and formed of ITO, for example, is formed on the second electrode 2. Furthermore, the common electrode 73
An alignment film 74 is formed on the top. In this way, the other substrate 71 is created.

The alignment film 67 of the one substrate 51 and the alignment film 74 of the other substrate 71 are first formed into a resin film, the resin film is baked at, for example, 180 ° C., and a rubbing treatment is performed in one direction. After that, it is created by performing rubbing cleaning. The rubbing cleaning is a processing of ultrasonically cleaning the surface of the substrate subjected to the rubbing treatment with an organic solvent such as isopropyl alcohol, and is a processing for removing dirt and the like generated during the rubbing.

The one and the other substrates 51 and 71 on which the respective members are formed as described above are the alignment films 6 of the respective substrates.
The surfaces of 7, 74 are arranged so as to face each other, and are bonded by an adhesive containing a spacer of 4.5 μm, for example. The adhesive is formed on the peripheral portion of either one of the substrates by a screen printing method. At this time, an injection hole for injecting liquid crystal is provided, and the liquid crystal material is injected through the injection hole by a vacuum injection method. As a result, the liquid crystal layer 75 interposed between the pair of substrates 51 and 71 is formed.

As the liquid crystal material, for example, a guest-host type material in which a black dichroic dye is mixed in nematic liquid crystal is used. In this embodiment, a nematic liquid crystal manufactured by Merck & Co., Inc. under the trade name ZLI4792 (refractive index anisotropy Δ
n = 0.13) was used as a dichroic dye, and a mixture of an azo dye and an anthraquinone dye was used. Further, 1.3% of a chiral agent was mixed in the liquid crystal material. As the chiral agent, S-811 manufactured by Merck & Co. was used. With this chiral agent, the twist pitch P of liquid crystal molecules is
Since 0 is set to 5 μm and the thickness d of the liquid crystal layer 75 is set to 4.5 μm by the spacer, d / P0 is set to about 0.9.

FIG. 3 shows each alignment film 67, when the substrates are bonded together.
It is a figure which shows the relationship of the rubbing process directions 67a and 74a given to 74. In this way, the substrates 51 and 71 are bonded so that the rubbing treatment direction 67a applied to the alignment film 67 and the rubbing treatment direction 74a applied to the alignment film 74 are opposite to each other. Therefore, the twist angle of the liquid crystal molecules between the substrates is about 360 °. The reflection type liquid crystal display device 61 having such a structure performs display according to an operation principle substantially similar to that of the white-tailer type guest-host mode liquid crystal display device. In the white-tailor type guest-host mode liquid crystal display device, the twist angle of the liquid crystal molecules between the substrates is 720 ° or more.

The picture element 76a shown in FIG. 2 shows the alignment state of the liquid crystal molecules 75a and the dichroic dye 77 when no voltage is applied. In this case, the liquid crystal molecules 75a are the substrates 51 and 7.
The twisted orientation is 360 ° between 1 and the dichroic dye 77 is also oriented along the liquid crystal molecules 75a. At this time, the other substrate 71
The incident light that has entered from the side is absorbed by the dichroic dye 77 even if it is light of any polarized light, resulting in black display.

On the other hand, the picture element 76b shows the alignment state of the liquid crystal molecules 75a and the dichroic dye 77 when a voltage is applied. In this case, the liquid crystal molecules 75a have a comparatively large alignment regulating force of the alignment films 67 and 74. In the portions apart from the weak alignment films 67 and 74, the dichroic dye 77 is aligned along the liquid crystal molecules 75a in the electric field direction. At this time, the incident light incident from the other substrate 71 side is not absorbed by the dichroic dye 77 but reflected by the reflective electrode 54 and emitted, so that color display based on the color filter 72 is performed.

The structure of the TFT element 55 is not limited to the bottom gate structure as described above, and it is also within the scope of the present invention to provide a TFT element having a top gate structure, for example. Further, as the gate, source and drain electrodes 56 to 58, in addition to the above-mentioned metal materials, metals such as Al and Ti, alloys of Al and Si, and K.
It is also within the scope of the present invention to use an alloy of r and Ta. Further, as the gate insulating film 62, S
It is also possible to use an insulating material such as iO ₂ . Further, in this embodiment, the TFT element 55 is an a-Si TFT.
Although the device has been described, it is also possible to use a p-SiTFT device.

Further, in this embodiment, since the refractive index anisotropy Δn of the liquid crystal material is set to 0.13 and the thickness d of the liquid crystal layer is set to 4.5 μm, Δn · d is about 0.585 μm. Δ
The value of n · d is not limited to the above value, but is preferably 1.0 μm or less, more preferably 0.6 μm or less. If Δn · d is too large, light is rotated by the liquid crystal layer 75, and the absorption of the dichroic dye 77 becomes insufficient.

FIG. 4 is a cross-sectional view showing stepwise a method of forming the recesses 60a and 60b on the surface of the reflective electrode 54 of the one substrate 51. As described above, the TFT is formed on the insulating substrate 78.
After the element 55 is formed, a resist film 81 is formed on the surface of the insulating substrate 78 so as to cover the TFT element 55, as shown in FIG. The resist film 81 is realized by, for example, a product name OFPR-800 manufactured by Tokyo Ohka Co., Ltd.,
The resist film material is applied by a spin coating method in which the rotation speed is set to 500 rpm to 3000 rpm. In this embodiment, the resist film material is applied at a rotation speed of 3000 rpm for 30 seconds to form a resist film 81 having a film thickness of 1.2 μm.
It was created. After application, prebaking treatment (heat treatment) is performed at 100 ° C. for 30 minutes.

Next, as shown in FIG. 4B, a light transmitting region 82 is formed in a predetermined pattern on the resist film 81 applied.
A mask 82 on which a and the light shielding region 82b are formed is arranged, and an exposure process is performed by the light 83. After that, for example, manufactured by Tokyo Ohka Co., Ltd., product name NMD-3 (2.38%)
The development processing is performed by. This allows the mask 82
A convex portion corresponding to the pattern is formed.

A substrate as described above is formed, for example, at 120.degree.
By performing the heat treatment at ˜250 ° C., the convex portion 84 having sharpened corners and smoothed is formed as shown in FIG. In this example, heat treatment was performed at 180 ° C. for 30 minutes. Further, a resist material similar to the resist film 81 described above is applied to cover the formed convex portions 84, and an organic insulating film 66 composed of the resist material and the convex portions 84 is formed. The application of the resist material is performed by, for example, a spin coating method under the conditions of 920 rpm to 3500.
It is selected for 20 seconds at rpm. In this embodiment, the resist material is applied at 2200 rpm for 20 seconds, and 1 μm is applied.
An organic insulating film 66 having a thickness of 3 was formed. The surface of the formed organic insulating film 66 becomes uneven due to the convex portion 84.

Subsequently, a contact hole 59 is formed in the organic insulating film 66 by exposure and development processing. Further, the metal film used as the reflective electrode 54 is the organic insulating film 6.
6 is formed. As the metal film, for example, Al, N
i, Cr and Ag can be used. The thickness of the metal film is selected to be about 0.01 μm to 1.0 μm. In this example, Al was formed by a vacuum evaporation method. Further, the formed metal film is exposed, developed and etched to form a reflective electrode 54 as shown in FIG. 4 (4). Since the surface of the organic insulating film 66 is uneven on the surface of the reflective electrode 54, the recess 6
0a and 60b are formed to be uneven.

FIG. 5 is a plan view showing a mask 82 used when forming the organic insulating film 66 having an uneven surface. A plurality of convex portions 84 made of a resist material are formed using the mask 82 as described above, and the organic insulating film 66 is formed by coating the convex portions 84 with a resist material. The shape and arrangement pattern of the protrusions 84 are determined by the light-transmitting area 82a and the light-shielding area 82b of the mask 82, and thus the shape and arrangement pattern of the recesses 60a and 60b on the organic insulating film 66 are also determined. The array pattern of the translucent regions 82a of the mask 82 is, for example, as shown in the drawing, each of the picture elements 76c to 76.
It is arranged the same in f.

FIG. 6 is a plan view showing another mask 85. In the mask 85, the adjacent picture elements are arranged to be inverted with respect to each other, as shown in the drawing. That is, picture element 7
6c, the arrangement pattern of the picture element 76c and the picture elements 76d and 76e has a line-symmetrical relationship, and the other picture elements 76d to 7d.
The same applies to 6f.

As the mask used when forming the organic insulating film 66 having the uneven surface, the mask 8 is used.
In addition to 2,85, the following masks 86 to 90 can be used.

FIG. 7 is a plan view showing the distance r between the plurality of recesses 60 on the surface of the reflective electrode 54. Further, FIG. 8 is a graph showing the relationship between the distance r and the number of existing distances r on the surface of one reflective electrode 54. In this embodiment, preferably, the plurality of recesses 60 are formed by one reflective electrode 54.
However, in order to arrange the recesses 60 in a true sense, the recesses 60 as shown in FIG.
The distances r1 to r7 must be present at the same frequency. In the case of an ideal array, the symbol L1 in FIG. 8 is obtained, but in practice, when the distance r is infinitely close to 0, there are few or no symbols.
It becomes like 2. For this reason, interference of reflected light occurs, resulting in deterioration of display quality.

In order to eliminate the interference of the reflected light as described above, a mask is used to form the recesses 60 that overlap each other.

FIG. 9 is a plan view showing still another mask 86-90. The mask 86 shown in FIG. 9 (1) has a light-transmitting region 86a of one size formed therein, and has a region where the light-transmitting region 86a overlaps. The other area is a light shielding area 86b. In the mask 87 shown in FIG. 9 (2), the translucent regions 87a and 87b of two sizes are provided.
Is formed, and has a region where the translucent regions 87a and 87b overlap. The other area is a light shielding area 87c. The mask 88 shown in FIG. 9C has light-transmitting regions 88a, 88b, and 88c of three sizes, and the other regions are light-shielding regions 88d. Figure 9 (4)
The light-transmissive regions 89a, 89b, 89c of three sizes are formed on the mask 89 shown in FIG. 3, and the light-transmissive regions 89a, 89b, 89c overlap each other. The other area is a light shielding area 89d. In the mask 90 shown in FIG. 9 (5), the light-transmitting regions 90a having two different sizes,
90b is formed, and the other regions are light-shielding regions 90.
c.

Any of the above-mentioned masks 82, 85-90
Even if the reflective electrode 5 is used,
4 can be formed. The masks 82 and 8
For the light-transmitting and light-shielding regions formed in 5 to 90, light-transmitting / light-shielding portions are selected according to the photosensitivity (negative or positive type) of the resist material used. In order to eliminate the interference of the reflected light as described above, FIGS. 9 (1), 9 (2) and 9 (4) are used.
Masks 86, 87, 89 as shown in FIG.

FIG. 10 is a sectional view showing the projections 84a and 84b formed on the insulating substrate 78 as described above. FIG. 10A shows the case where a mask in which the convex portions do not overlap is used, and FIG. 10B shows the case where a mask in which the convex portions overlap. As shown in FIG. 10 (1), all the protrusions 84a formed by using a mask such that the protrusions do not overlap each other have a height h1 and protrude from the surface of the substrate 51 and the surface of the substrate 51. The angle formed with the straight line assumed along the inclination of the portion 84a is the angle α1.

On the other hand, as shown in FIG. 10B, the protrusions 84a formed by using a mask in which the protrusions overlap each other,
One convex portion 84a of 84b is similar to the convex portion 84a shown in FIG. 10 (1), and the other convex portion 84b is formed by the overlapping region of the light-transmitting region of the mask used. A recess 84c is formed. The length from the most recessed point of the recess 84c to the apex of the protrusion 84b is h2, is parallel to the surface of the substrate 51, and has a plane having the most recessed point of the recess 84c and the protrusion from the plane. The angle formed with the straight line assumed along the inclination of 84b is the angle α2.

As shown in FIG. 1, the reflective electrode 54 in this embodiment has a substantially rectangular shape, and the length in the longitudinal direction of the reflective electrode 54 excluding the TFT element 55 portion is A1, and the longitudinal length excluding the TFT element 55 portion is the same. The length in the lateral direction orthogonal to the direction is B1, the width of one side of the peripheral edge portion 54a of the reflective electrode 54 in the direction parallel to the longitudinal direction is A2, and the width in the lateral direction of the peripheral edge portion 54a of the reflective electrode 54 is defined as If one width in the parallel direction is B2, (A2 / A1) × 100, and (B2
/ B1) × 100 is selected in the range of 0.3% or more and 10% or less.

In this embodiment, A1 is set to 300 μm and B1
1 was 150 μm. A2 and B2 are both 3μ
m, and (A2 / A1) × 100 = 1%,
(B2 / B1) × 100 = 2%. In the case of this embodiment, if A2 is in the range of 0.9 μm to 30 μm, B2 is
Satisfies the above-mentioned condition in the range of 0.5 μm to 15 μm. When the range of A2 and B2 is smaller than the above range,
It was confirmed that peeling of the reflective electrode 54 occurs due to permeation of the etching liquid during etching when forming the reflective electrode 54. Further, if the range of A2 and B2 is larger than the above range, the effect of reflecting light in all directions in the direction perpendicular to the display screen becomes low, and the brightness of the display image cannot be improved.

The following Table 1 shows X ((A2 / A1) × 10
The relationship between the value of 0 or (B2 / B1) × 100), the display state of the reflective liquid crystal display device, and the occurrence of peeling of the reflective electrode 54 is shown. When X = 0%, the display state is good, but peeling of the reflective electrode 54 occurs,
When X = 20%, peeling does not occur, but the specularity is too strong, so even if light from any direction is reflected, the effect of reflecting it in a direction substantially perpendicular to the display screen may not be sufficiently obtained. confirmed. X = 0.3%,
In the cases of 5% and 10%, it was confirmed that the display state was almost good, and the peeling of the reflective electrode 54 did not occur, or almost never occurred.

[0069]

[Table 1]

FIG. 11 is a plan view showing another example of the recess 60a formed in the reflective electrode 54. Although the above-described example is an example in which the recess 60a is not provided at all in the peripheral portion 54a, an example in which the recess 60a is formed in the peripheral portion 54a as shown in the figure also belongs to the scope of the present invention. However, as described above, the recess 60 with respect to the entire area of the peripheral portion 54a is formed.
The area except a, that is, the area shown by hatching in FIG. 11, is selected to be 60% or more and 100% or less. When the ratio is less than 60%,
It was confirmed that the etching liquid penetrated between the reflective electrode 54 and the organic insulating film 66 during the etching for forming the reflective electrode 54, and the reflective electrode 54 was peeled off.

FIG. 12 shows another one substrate 6 according to the present invention.
It is a top view which shows 9. The one substrate 69 is made of the same material as the one substrate 51, but the reflective electrode 54
Instead of the recesses 61a, 61b, the protrusions 68a, 6b
8b is provided. Convex portions 68a, 68b
Are provided under the same conditions as described above and in the same manner as the recesses 61a and 61b. Convex portions 68a, 68b
By providing the above, the same effect as described above can be obtained.

FIG. 13 is a sectional view showing another embodiment of the present invention, which is a simple matrix type reflection type liquid crystal display device 91 in which the surface of the reflection electrode is made uneven by another method. FIG. 14 is a plan view showing a mask 99 used when forming the recess 92a in the insulating substrate 123 of the reflective liquid crystal display device 91. The reflective liquid crystal display device 91 includes a pair of substrates 92, 9 at least one of which is transparent.
5 is formed via the liquid crystal layer 98.

An insulating substrate 123 which is made of glass and constitutes one substrate 92 of the pair of substrates 92 and 95.
Although a plurality of strip-shaped reflective electrodes 93 arranged in parallel with each other at intervals are formed on the surface of,
A recess 92a is formed in a predetermined area of the insulating substrate 123 where the reflective electrode 93 is to be formed. This recess 92a is
First, a photoresist film is formed on the insulating substrate 123,
The mask 99 shown in FIG. 14 is formed by arranging it on the photoresist film, exposing it, developing it, and etching it with hydrofluoric acid, for example. The mask 99 shown in FIG. 14 has a light-transmitting region 99a and a light-shielding region 99b similar to the masks 82, 85 to 90 in a region corresponding to one reflective electrode having a size of A1 × B1. Further, since a recess is formed in the peripheral portion having a predetermined length inward from the peripheral edge of the reflective electrode under the same conditions as described above, the lengths A2 and B2 of the mask 99 are correspondingly formed. The arrangement of the light-transmitting region 99a and the light-shielding region 99b in the peripheral portion having the is selected.

Insulating substrate 123 having recess 92a formed therein
An Al film having a thickness of 0.5 μm is formed on the upper surface by, for example, a vacuum deposition method. Next, the Al film is exposed and developed,
By further etching, the reflective electrode 93 is formed at a predetermined position. A recess 93 a is formed on the surface of the reflective electrode 93 by the recess 92 a of the insulating substrate 123. Further, an alignment film 94 is formed on the insulating substrate 123 so as to cover the reflective electrode 93. In this way, the one-sided substrate 92 is produced.

On the insulating substrate 124 made of, for example, glass, a plurality of translucent strip electrodes 96 are formed which are arranged in a direction orthogonal to the reflective electrodes 93, and the alignment film 97 is further formed. Is formed. In this way, the other substrate 95 is formed, and a pair of such substrates 92,
95 are arranged so that the alignment films 94 and 97 face each other, and are bonded to each other with the liquid crystal layer 98 interposed therebetween in the same manner as in the reflective liquid crystal display device 61. The portion where the reflective electrode 93 and the strip electrode 96 overlap is a display pixel. The liquid crystal layer 98 is realized by the same material as the liquid crystal layer 75. Also,
The alignment treatment directions of the alignment films 94 and 97 are also the same as those of the alignment films 67 and
It is arranged similarly to 74.

By directly forming the recess 92a in the insulating substrate 123 made of glass as described above, the reflective electrode 93 can be formed.
The surface of can be made uneven.

When the recess 93a is not formed in the peripheral edge of the reflective electrode 93, the portion of the glass insulating substrate 123, which corresponds to the peripheral edge of the area where the reflective electrode 93 is to be formed, is covered. It is also possible to use a mask to form the recess 92a on the surface of the insulating substrate 123 as described above by a known sandblast method or polishing method.
Also, it can be formed by sprinkling beads. Furthermore, to form the Al-Si alloy film, a method for etching the alloy film, a method of forming a SiO ₂ film having an uneven surface by a CVD method or a SiO ₂ film is formed, etching the SiO ₂ film It can also be formed by a method such as.

FIG. 15 is a sectional view showing the steps of the polishing method step by step. By the polishing method, spherical beads 121 are dispersed on the surface of an insulating substrate 123 as shown in FIG. 15A, and insulating substrate 123 on which beads 121 are dispersed as shown in FIG. 15B. The plate-shaped member 122 is arranged on the surface of, and rubbed while applying pressure and shifting it to the left and right and diagonally, and finally to FIG.
As shown in (3), the plate member 122 and the beads 1
This is a method of forming a recess 92a on the surface of the insulating substrate 123 by removing 21.

The bead spraying method is a method disclosed in Japanese Patent Application Laid-Open No. 4-308816 by the applicants of the present invention, in which an organic insulating resin containing fine particles is applied to the substrate surface and baked. This is a method of forming a large number of fine irregularities by using.

FIG. 16 shows an active matrix type reflection type liquid crystal display device 11 which is still another embodiment of the present invention.
It is a top view which expands and shows one board | substrate 101 of 9. The reflective liquid crystal display device 119 is configured by interposing a liquid crystal layer between a pair of substrates 101 and 112, at least one of which is translucent.

A plurality of signal wirings 102 are provided in parallel with each other on an insulating substrate 125, which constitutes one of the pair of substrates 101 and 112 and is made of, for example, glass. From the signal wiring 102 to the lower electrode 10
5 is branched. Further, a plurality of substantially rectangular reflecting electrodes 103 are arranged in a matrix. The distance W between the reflective electrode 103 and the signal line 102 is such that they maintain insulation.
It is provided with 5 open. Reflection electrode 103 and signal wiring 10
2 is connected via a two-terminal element 104 which is a switching element. The two-terminal element 104 includes the lower electrode 105, the upper electrode 106, and the electrodes 105 and 10.
It is configured to include an insulating layer 109 interposed between the six. The upper electrode 106 and the reflective electrode 103 are connected by the contact hole 107 as described later.

A plurality of recesses 111a and 111b are provided on the surface of the reflective electrode 103, so that the surface is uneven. A plurality of recesses 111a,
Although 111b exists on almost the entire surface of the reflective electrode 103, the reflective electrode 1 shown by hatching in FIG.
03 in the peripheral portion 103a, that is, a region having a predetermined length inward from the peripheral edge of the reflective electrode 103,
The recesses 111a and 111b are formed under the same conditions as in the above-described embodiment.
Is provided. What is illustrated is the case where no recesses 111a and 111b are provided in the peripheral edge portion 103a.
In this embodiment, the predetermined length is A2, B2.
It is represented by.

FIG. 17 is a sectional view showing the reflective liquid crystal display device 119. A method of manufacturing the reflective liquid crystal display device 119 will be described with reference to FIG. For example, the base coat film 1 is first formed on the insulating substrate 125 made of glass or the like.
08 is formed. The base coat film 108 is realized by forming a Ta ₂ O ₅ film having a thickness of 5000Å by a sputtering method. In addition, the insulating substrate 1
As 25, non-alkali glass, borosilicate glass, soda glass, or the like can be used. In this example, Corning's trade name # 7059 was used. Although formation of the base coat film 108 can be omitted, by forming the base coat film 108, contamination from the insulating substrate 125 can be prevented and good display characteristics can be obtained.

Next, the signal wiring 102 and the lower electrode 105 are formed on the base coat film 108. First,
For example, by the reactive sputtering method, 3
A Ta film having a thickness of 000Å is formed, and the Ta film is patterned into a predetermined shape by photolithography. At the time of sputtering the Ta film, Ta having a purity of 99.99% was used as a target. A mixed gas of argon and nitrogen was used as the reaction gas. The nitrogen content can be adjusted by adjusting the nitrogen gas flow rate with respect to the total flow rate of the argon gas and the nitrogen gas. In this embodiment, the nitrogen concentration is 4.3%. By selecting the nitrogen concentration in the range of 3% to 7%, the two-terminal element 104 having good non-linear characteristics can be obtained, and more preferably 4% to 5.5%.

The patterned Ta film is anodized using a 1% ammonium tartrate solution as an electrolytic solution. As a result, the oxidized portion of the surface of the Ta film is covered with the insulating layer 109.
Becomes Moreover, the signal wiring 1 is formed by the portion which is not oxidized.
02 and the lower electrode 105 are formed. Insulating layer 109
The thickness is selected to be, for example, 600Å.

Further, a metal film to be the upper electrode 106 is formed on the base coat film 108 on which the insulating layer 109 is formed. The metal film is formed by, for example, a sputtering method and patterned by a photolithography method to form the upper electrode 106. Upper electrode 106
For example, Ta, Cr, Ti, Al, or the like can be used, and Ti is used in this embodiment. In this way, the two-terminal element 104 is formed.

On the base coat film 108 on which the two-terminal element 104 is formed, the organic insulating film 110 having an uneven surface is formed in the same manner as in the above-mentioned embodiment. Further, the reflective electrode 103 is formed on the organic insulating film 110, and the recesses formed on the surface of the organic insulating film 110 also form recesses 111a and 111b on the surface of the reflective electrode 103. Therefore, the reflective electrode 1 of the organic insulating film 110
In the area where 03 is to be formed, the reflective electrode 1 as described above
The recesses corresponding to the recesses 111a and 111b of the surface 03 are formed. Further, the organic insulating film 110 is provided with a contact hole 107 for connecting the reflective electrode 103 to the upper electrode 106. An alignment layer 120 is formed on the organic insulating layer 110 having the reflective electrode 103 formed thereon to cover the reflective electrode 103. In this way, the first substrate 1
01 is created.

On the insulating substrate 126 which constitutes the other substrate 112, the color filter 1 is formed in the same manner as in the above embodiment.
13 is formed. The color filter 113 includes, for example, a cyan filter 113a and a red filter 113b provided corresponding to each picture element. Color filter 1
A common electrode 114 having a thickness of 2000 Å realized by, for example, ITO is formed on the layer 13. The common electrode 114 is patterned in a stripe shape by using a photolithography method. An alignment film 115 is formed on the color filter 113 so as to cover the patterned common electrode 114. In this way, the other substrate 112 is created.

The one and the other substrates 101 and 112 on which the respective members are formed in this manner are bonded together with the liquid crystal layer 116 interposed therebetween in the same manner as in the above embodiment. Liquid crystal layer 11
6 is realized by the same material as the liquid crystal layer 75. The reflection type liquid crystal display device 11 configured in this way
When the voltage of 9 is not applied and the voltage is applied, display is performed according to the same operation principle as that of the reflective liquid crystal display device 61. A picture element 117a shown in FIG. 17 shows a time when no voltage is applied, and a picture element 117b shows a time when a voltage is applied.

As described above, according to this embodiment, the reflective electrodes 54, 93 and 103 have uneven surfaces, and the peripheral portions 54a and 103a thereof are provided with relatively few unevenness.
Alternatively, no unevenness is formed. Reflective electrode 54,
In order to make the surfaces of 93 and 103 uneven, the surface on which the reflective electrodes 54, 93 and 103 are to be formed is made uneven, and after forming a metal film to be a reflective electrode on the entire surface, The reflective electrodes 54, 93 and 103 are formed by patterning the metal film. Etching is used to form the pattern of the metal film, and the unnecessary metal film is dissolved and removed. The reflective liquid crystal display device 61, 9 described above
1, 119, there are relatively few or no recesses or protrusions provided on the peripheral portions of the reflective electrodes 54, 93, 103, and therefore the reflective electrodes on the surface on which the reflective electrodes 54, 93, 103 are formed. There are relatively few or no recesses or protrusions formed in the portion corresponding to the peripheral portion. Therefore, in the edge portion of the metal film to be left, the interface between the metal film and the surface on which the reflective electrode is to be formed becomes relatively small, and the etching solution is not removed during the etching for patterning the metal film. The amount that permeates from the interface between the two decreases.

Therefore, the reflective electrodes 54, 93, 103
Is prevented from being peeled off from the edge portion, and generation of defective picture elements is prevented. Further, the peeled reflective electrode prevents a short circuit from occurring between another reflective electrode and the common electrode facing the reflective electrode.

Further, since the surfaces of the reflection electrodes 54, 93, 103 are uneven, even if incident light from any direction can be reflected in a direction substantially perpendicular to the display screen, a bright display image can be obtained. Is obtained. Further, the reflective electrodes 54, 93, 103 function as a reflective plate, and as a result, parallax is improved when compared with a reflective liquid crystal display device in which a reflective plate is provided on the opposite side of the substrates 51, 92, 101 from the liquid crystal layer side. Does not occur.

Although the TFT element 55 and the two-terminal element 104 are provided as the switching elements in the above-described embodiments, the two-terminal element 104 is, for example, M.
It is realized by IM element. Also, a varistor element, a diode ring element, or the like can be used as the two-terminal element.

Although the guest-host mode has been described as the display mode of the liquid crystal display device in this embodiment, in addition to the guest-host mode, PDLC (PolymerDis
Persed Liquid Crystal) mode, a mode using one polarizing plate, a phase transition mode, and a mode using ferroelectric liquid crystal are also applicable. Further, in the above-described embodiment, an example in which a complementary color filter is used as a color filter has been described, but it is also possible to use red, green, and blue filters, and a liquid crystal display device that performs monochrome display without using color filters. It is also possible to apply to.

In this embodiment, the reflective electrodes 54, 103
Although the wirings 52, 53, 102 are formed on the organic insulating films 66, 110 with a space W1 to W5 therebetween, the organic insulating films 66, 1 cover the wirings 52, 53, 102.
10 is formed, the reflective electrodes 54 and 103 are connected to the wiring 5
It is also possible to provide them so as to overlap with 2, 53 and 102. In this case, the reflective electrodes 54 and 103 are provided at intervals such that adjacent reflective electrodes maintain insulation. As a result, the areas of the reflective electrodes 54 and 103 are enlarged, and a brighter display image can be obtained.

18 and 19 show the two-terminal element 1
4 is a plan view showing one substrate 101 provided with 04 and the reflective electrode 103 so as to overlap the signal wiring 102. FIG. As shown in FIG. 18, in the overlapping portion of the signal wiring 102 and the reflective electrode 103, the signal wiring 102 is formed.
When the length C1 in the direction orthogonal to the longitudinal direction of is selected to be a relatively large value, the peripheral edge portion 103 of the reflective electrode 103 is
The boundary line between a and the other area (in FIG. 18,
A line indicated by a chain double-dashed line) is selected at a length C2 (<C1) from the overlapping end of the signal wiring 102 on the side of the reflective electrode 103 toward the inside of the signal wiring 102. For example, when the length C1 is 2 μm, the length C2 is selected to be 0.5 μm.

Further, as shown in FIG. 19, at the overlapping portion of the signal wiring 102 and the reflective electrode 103, the length C3 in the direction orthogonal to the longitudinal direction of the signal wiring 102 is obtained.
Is selected to be a relatively small value, the reflective electrode 103
From the periphery of the inside of the reflective electrode 103 to the length C4 (>
The region having C3) is the peripheral edge portion 103a. For example, when the length C3 is 0.1 μm, the length C4 is 0.
5 μm is selected.

The adjacent reflective electrodes 103 are provided with the intervals W5 and W6. The distance between the reflective electrodes 103 in the direction perpendicular to the longitudinal direction of the signal wiring 102 is W5.
In addition, the distance between the reflective electrodes 103 in the parallel direction is selected as W6.

FIG. 20 is a plan view showing the one substrate 51 in which the TFT element 55 is provided and the reflective electrode 54 is provided so as to overlap the gate bus wiring 52 and the source bus wiring 53. For example, the gate bus wiring 52 and the reflective electrode 5
When the length E1 in the direction orthogonal to the longitudinal direction of the gate bus line 52 is selected to be a relatively large value in the overlapping portion with 4, the length from the peripheral edge of the reflective electrode 54 toward the inside of the reflective electrode 54 is increased. A region having a height E2 (<E1) is the peripheral edge portion 54a. For example, when the length E1 is 3 μm, the length E2 is selected to be 0.5 μm.

Further, when the length E3 in the direction orthogonal to the longitudinal direction of the source bus line 53 is selected to be a relatively small value in the overlapping portion of the source bus line 53 and the reflective electrode 54, for example, the reflective electrode 54. A region having a length E4 (> E3) from the peripheral edge toward the inside of the reflective electrode 54 is defined as the peripheral edge portion 54a. For example, when the length E3 is 0.2 μm, the length E4 is selected to be 0.5 μm.

It should be noted that the distance W between adjacent reflective electrodes 54 is W.
It is provided with 7, W8 open. The distance between the reflection electrodes 54 in the direction parallel to the longitudinal direction of the source bus line 53 is W7.
In addition, the distance between the reflective electrodes 54 in the direction parallel to the longitudinal direction of the source bus line 52 is selected as W8.

[0102]

As described above, according to the present invention, the reflective electrode has an uneven surface, and the peripheral portion having a predetermined length from the peripheral edge of the reflective electrode toward the inside has a relatively irregular surface. There are few. Or not provided at all. Therefore, when patterning the reflective electrode, the interface between the metal film and the surface on which the reflective electrode is to be formed is relatively small at the edge portion of the metal film that remains as the reflective electrode, and the etching liquid is used as an interface between the two. The amount that permeates through is reduced.
Therefore, peeling from the edge portion of the reflective electrode is prevented, and generation of defective picture elements is prevented. In addition, the peeled reflective electrode also prevents a short circuit from occurring between the other reflective electrode and the strip electrode or the common electrode. Further, since the surface of the reflective electrode is uneven, any pixel shows the same reflective characteristic, and a uniform and high-contrast bright display image can be obtained. Furthermore, since the reflective electrode functions as a reflective plate, parallax does not occur.

Further, according to the present invention, the recesses or protrusions in one reflective electrode are arranged irregularly. The recesses or protrusions are formed of one type or two or more types having different sizes. In addition, the arrangement pattern of the recesses or the protrusions is the same in each reflective electrode. Also,
The arrangement pattern of the recesses or the protrusions is arranged so as to be inverted between adjacent reflective electrodes. Since all of them have the same reflection characteristic in any picture element, it is possible to obtain a bright display image with uniform and high contrast.

According to the present invention, the reflective electrode and the lead-out electrode are formed on the surface of one substrate on the liquid crystal layer side with an interval for maintaining insulation therebetween. Also, it is possible to produce a reflective liquid crystal display device which is relatively bright and has excellent display quality with less peeling of the reflective electrode.

[Brief description of drawings]

FIG. 1 is a reflection type liquid crystal display device 6 which is an embodiment of the present invention.
It is a top view which expands and shows the one board | substrate 51 of 1.

FIG. 2 is a cross-sectional view showing a reflective liquid crystal display device 61.

FIG. 3 is a diagram showing a relationship between rubbing processing directions 67a and 74a applied to respective alignment films 67 and 74 when substrates are bonded together.

FIG. 4 is a cross-sectional view showing stepwise a method of forming recesses 60a and 60b on the surface of a reflective electrode 54 on the one substrate 51.

FIG. 5 is a plan view showing a mask 82 used when forming an organic insulating film 66 having an uneven surface.

FIG. 6 is a plan view showing another mask 85.

7 is a plan view showing a distance r between a plurality of recesses 60 on the surface of the reflective electrode 54. FIG.

8 is a graph showing a relationship between the distance r and the number of existing distances r existing on the surface of one reflective electrode 54. FIG.

FIG. 9 is a plan view showing still another masks 86 to 90.

FIG. 10 shows protrusions 84a, 8 formed on the insulating substrate 78.
It is sectional drawing which shows 4b, respectively.

11 is a plan view showing another example of a recess 60a formed in the reflective electrode 54. FIG.

FIG. 12 is a plan view showing another one substrate 69 according to the present invention.

FIG. 13 is a cross-sectional view showing another embodiment of the present invention, a reflective liquid crystal display device 91 in which the surface of the reflective electrode 54 is made uneven by another method.

FIG. 14 is an insulating substrate 1 of the reflective liquid crystal display device 91.
A mask 99 used when forming the recess 92a in the groove 23.
FIG.

FIG. 15 is a cross-sectional view showing the processing steps of the polishing method step by step.

FIG. 16 is an enlarged plan view showing one substrate 101 of a reflective liquid crystal display device 119 which is another embodiment of the present invention.

FIG. 17 is a cross-sectional view showing a reflective liquid crystal display device 119.

FIG. 18 is a plan view showing one substrate 101 in which a reflective electrode 103 is provided so as to overlap a signal wiring 102.

FIG. 19 is a plan view showing another one substrate 101 in which a reflective electrode 103 is provided so as to overlap a signal wiring 102.

FIG. 20 is a plan view showing one substrate 51 in which a reflective electrode 54 is provided so as to overlap with gate and source bus wirings 52 and 53.

FIG. 21: One substrate 3 of a conventional reflective liquid crystal display device 30
It is a top view which shows 1.

FIG. 22 is a cross-sectional view showing the reflective liquid crystal display device 30.

FIG. 23 is a plan view showing a substrate 12 having TFTs 11 used in still another conventional active matrix system.

24 is a cross-sectional view of the substrate 12 shown in FIG.
28-X28 is a cross-sectional view when viewed from 28-X28.

[Explanation of symbols]

 51, 69, 92, 101 One-sided substrate 52 Gate bus wiring 53 Source bus wiring 54, 93, 103 Reflective electrode 55 TFT element 59, 107 Contact hole 60a, 60b, 111a, 111b Recess 61, 91, 119 Reflective liquid crystal display Device 66,110 Organic insulating film 68a, 68b Convex portion 71,95,112 Other substrate 73,114 Common electrode 75,98,116 Liquid crystal layer 96 Strip electrode 102 Signal wiring 104 Two-terminal element

Claims (8)

[Claims] 1. A liquid crystal layer-side surface of one substrate of a pair of substrates, which are opposed to each other with a liquid crystal layer interposed therebetween and at least one of which has a light-transmitting property, is provided from a side of the other substrate having a light-transmitting property. The liquid crystal layer side surface of the other substrate has a reflective electrode that reflects the incident light, in a reflective liquid crystal display device having a translucent electrode, the reflective electrode has an uneven surface, The reflective liquid crystal display device is characterized in that, in the peripheral portion, the ratio of the region excluding the concave portions or the convex portions of the uneven surface to the peripheral region is selected in the range of 60% or more and 100% or less. 2. A liquid crystal layer side surface of one substrate of a pair of substrates, which are opposed to each other with a liquid crystal layer interposed therebetween and at least one of which has a light transmitting property, is provided from a side of the other substrate having a light transmitting property. A plurality of reflective electrodes which are display picture elements for reflecting incident light, a drawing electrode supplied with a display voltage applied to each reflecting electrode, and a voltage from the drawing electrode to the plurality of reflecting electrodes. In a reflective liquid crystal display device having a plurality of switching elements for individually supplying / cutting off, and a liquid crystal layer side surface of the other substrate having a translucent common electrode covering substantially the entire liquid crystal layer side surface. The reflective electrode has a concave-convex surface, and in the peripheral portion of the reflective electrode, the ratio of the region excluding the concave portion or the convex portion of the concave-convex surface to the peripheral region is 60% or more and 100% or less. Anti-characterized by being selected in range Type liquid crystal display device. 3. The reflection electrode has a rectangular shape or a substantially rectangular shape, and one of a direction parallel to the direction of the peripheral edge portion of the reflection electrode with respect to a length of the reflection electrode in a direction parallel to the opposite ends of the reflection electrode. The reflection type liquid crystal display device according to claim 1 or 2, wherein the width ratio is selected in a range of 0.3% to 10%. 4. The reflective liquid crystal display device according to claim 1, wherein the concave portions or the convex portions of one reflective electrode are irregularly arranged. 5. The reflection type liquid crystal display device according to claim 4, wherein the recess or the protrusion has one type or two or more types having different sizes. 6. The arrangement pattern of the recesses or protrusions is
The reflective liquid crystal display device according to claim 4, wherein the reflective electrodes are selected in the same manner. 7. The arrangement pattern of the recesses or protrusions is
The reflective liquid crystal display device according to claim 4, wherein the reflective liquid crystal display devices are selected so as to be mutually inverted between adjacent reflective electrodes. 8. The reflective type electrode according to claim 2, wherein the reflective electrode and the lead-out electrode are formed on the surface of the one substrate on the liquid crystal layer side with a space therebetween for maintaining insulation therebetween. Liquid crystal display device.