JP2001091939A - Reflection type liquid crystal display device and electronic appliance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reflection type liquid crystal display device which can be made lightweight, small-sized and thin and which gives a bright display by using a metal substrate for one substrate, and to provide a reflection type liquid crystal display device which makes a color display possible by coloring an anodically oxidized film in the region corresponding to a pixel electrode. SOLUTION: In the liquid crystal device of this invention, a liquid crystal layer 15 is held between a metal substrate 14 and a transparent substrate facing the metal substrate, and a reflection face having a rugged pattern is formed on the liquid crystal layer side of the metal substrate to form a light-reflecting and diffusing face 14A. The light-reflecting and diffusing face 14A is coated with an anodically oxidized film 25, and further a plurality of transparent pixel electrodes 32 are formed on the anodically oxidized film. The anodically oxidized film in the region corresponding to each pixel electrode is colored. A counter electrode 18 is formed on the liquid crystal layer side of the transparent substrate.

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 having a pair of substrates provided with a liquid crystal layer interposed therebetween and an electronic device having the same, and more particularly, to a metal substrate or a pixel electrode having an anodized film. The present invention relates to a structure which is formed, colored, and used as a color filter.

[0002]

2. Description of the Related Art Various electronic devices such as a notebook personal computer, a portable game machine, and an electronic organizer often use a liquid crystal display device with low power consumption as a display unit. In particular, in recent years, demand for a liquid crystal display device capable of performing color display has been increasing with the frequent use of display contents. In addition, in response to a demand for extending the battery driving time of the electronic device, a reflective color liquid crystal display device that does not require a backlight device has been developed.

FIG. 10 is an enlarged schematic sectional view showing a main part of an example of a conventional reflection type color liquid crystal display device. The reflective color liquid crystal display device illustrated in FIG. 10 has a structure called an inner surface scattering type, and includes a pair of glass substrates 100 and 101,
A liquid crystal layer 102 sandwiched therebetween is provided, and a pixel electrode 107 made of an Al thin film or the like also serving as a reflection plate is provided on the surface of the glass substrate 100 on the liquid crystal layer 102 side with irregularities for irregularly reflecting light. It is formed in a state where it is set. Note that a sealing material is actually formed between the peripheral portions of the glass substrates 100 and 101 so as to be sandwiched between the glass substrates 100 and 101 to seal the liquid crystal layer 102. In FIG. Is omitted.

Here, a color filter 104 is formed on the surface of the glass substrate 101 on the light incident side on the liquid crystal layer 102 side, and a polarizing plate 106 is provided on the upper surface side of the glass substrate 101. In such an inner surface scattering plate type liquid crystal display device, the incident light L1 is diffusely reflected on the surface of the pixel electrode 107 after passing through the polarizing plate 106, the glass substrate 101, the color filter 104, and the liquid crystal layer 102.
After the polarization is changed according to the state, the reflected light passes through the color filter 104 and the glass substrate 101, and the polarization plate 10
6, the light is transmitted or not transmitted depending on the polarization state of the reflected light,
In the case of transmission, the color of the color filter 104 is made visible, and in the case of non-transmission, the color of the color filter 104 enters the observer's naked eye E as scattered light L2 in a state where the color is not directly visible. It is visually recognized as a display.

[0005]

In this type of conventional reflection type color liquid crystal display device, the substrates 100 and 101 for sandwiching the liquid crystal layer 102 are generally formed of glass substrates. . In recent years, further reduction in size, weight, and thickness has been required for portable telephone devices or portable information terminal devices to which this type of reflective color liquid crystal display device is applied. There is a demand for further reduction in the weight of the type color liquid crystal display device itself.

Considering the weight of this type of conventional reflection type color liquid crystal display device, the weight of the glass substrates 100 and 101 occupying the largest volume ratio occupies most of the weight. In order to reduce the weight of the display device, it is considered most effective to reduce the thickness of the glass substrate. However, the current glass substrate is sufficiently thin and has a thickness of about 0.3 mm, and it is difficult to further reduce the thickness in view of the strength of the glass itself.

Further, unlike the structure shown in FIG. 10, a light scattering / reflecting layer 108 is provided on the back side of the glass substrate 100 as shown by a two-dot chain line, and a pixel electrode 107 is formed in a flat surface without unevenness. Is also known.

With this structure, the light scattering / reflecting layer 108 manufactured in a separate process is formed on the back side of the glass substrate 100.
By sticking a light scattering reflection surface can be configured,
Although the layer structure formed on the upper surface side of the glass substrate 100 has an advantage that it can be simplified, since light is reflected on the rear surface side of the glass substrate 100, the reflection efficiency is poor, and a bright display can be obtained as a reflective liquid crystal display device. There was a difficult problem.

Further, in this type of conventional reflection type liquid crystal display device, a color filter 104 is generally provided on the surface of the glass substrate 101 on the light incident side on the liquid crystal layer 102 side for color display. This color filter 10
If the pixel electrode 4 is formed separately on the glass substrate 101 side, a step for forming the color filter 104 is separately required, which complicates the manufacturing process and the pixel electrode 10 serving as a light reflecting surface.
Since the distance from the surface 7 increases, there is a problem that color shift easily occurs according to the incident angle of the incident light.

The present invention has been made in view of the above-mentioned problems, and is intended to reduce the weight, thickness, and size of the entire device by using one of the substrates sandwiching the liquid crystal layer as a metal substrate.
An object is to provide a reflective liquid crystal display device in which a color display function is imparted to a metal substrate by coloring an anodized film formed on the metal substrate. In addition, the color display function formed on the metal substrate is made to correspond to each pixel electrode so that three primary colors can be displayed. Another object is to provide a reflective liquid crystal display device which is omitted.

Further, the present invention provides a pixel electrode having at least a surface on a liquid crystal layer side as a metal electrode provided with a colored anodic oxide film, and imparting a color filter function to the metal electrode itself. A reflective liquid crystal that eliminates the color shift of reflected light by omitting the color filter and providing a color filter function on the surface side of the light reflective pixel electrode so that the color filter can be arranged directly above the light reflective surface. An object is to provide a display device.

Another object of the present invention is to provide an electronic apparatus provided with a reflection type liquid crystal display device having the above-mentioned excellent characteristics.

[0013]

According to a first aspect of the present invention, there is provided a reflective liquid crystal display comprising a liquid crystal layer sandwiched between a metal substrate and a transparent substrate opposed to the metal substrate. A reflection surface having an uneven portion is formed on a surface of the metal substrate on the liquid crystal layer side to form a light reflection / diffusion surface; an anodic oxide film is coated on the light reflection / diffusion surface; A plurality of transparent pixel electrodes for driving the liquid crystal are formed,
The anodic oxide film at a position corresponding to each pixel electrode is colored, and an electrode on the opposite side is formed on the liquid crystal layer side of the transparent substrate.

In the anodic oxide film on the metal substrate, the anodic oxide film at the position corresponding to the pixel electrode is colored, so that the reflected light can be colored just above the reflecting surface of the metal substrate that reflects light. When the light transmission state of the liquid crystal layer is controlled by the pixel electrode and the electrode on the opposite side, the color of the anodic oxide film at the position corresponding to the pixel electrode can be displayed in color as a display color.

Further, if a metal substrate is used instead of the conventional glass substrate used in the reflection type liquid crystal display device,
Even if the strength is equivalent to that of the glass substrate, the metal substrate can be made thinner than the glass substrate. Therefore, it is possible to reduce the thickness, weight, and size as compared with the conventional structure using the glass substrate. Next, since the surface on the liquid crystal side of the metal substrate is directly used as the reflection surface, the reflection efficiency is good, and a bright high-quality display can be obtained.

Further, in the reflection type liquid crystal display device of the present invention, a liquid crystal layer is sandwiched between a pair of substrates, a plurality of pixel electrodes for driving liquid crystal are formed on the one substrate, and the other substrate is formed on the other substrate. An electrode on the opposite side for driving liquid crystal is formed opposite to the pixel electrode. At least a surface of the pixel electrode on the liquid crystal layer side is formed of a light-reflective metal electrode, and an anode is formed on a surface of the metal electrode on the liquid crystal layer side. An oxide film is formed, and the anodic oxide film is colored.

Since the anodic oxide film on the pixel electrode is colored, coloring can be performed by the anodic oxide film directly above the pixel electrode that reflects light, and the liquid crystal layer is formed by the pixel electrode and the electrode on the opposite side. When the light transmission state is controlled, the color of the anodic oxide film immediately above the pixel electrode can be displayed in color as a display color.

In the above-mentioned reflection type liquid crystal display device of the present invention, the anodic oxide film comprises a nonporous barrier layer and a porous cell layer, and a dye is injected into the pores of the cell layer. Alternatively, the structure may be characterized in that the anodic oxide film is colored.

In the above-mentioned reflection type liquid crystal display device of the present invention, the structure may be characterized in that the anodized film is colored by electrodeposition with a pigment.

In the above-mentioned reflection type liquid crystal display device of the present invention, the anodic oxide film may be colored by electrolytic coloring.

The coloring structure of the anodic oxide film can take various forms, whether it is a structure in which a dye is injected into the pores of the cell layer, a structure in which the pigment is colored by electrodeposition, or a color by electrolytic coloring. In any case, color display becomes possible with any structure.

In the above-mentioned reflection type liquid crystal display device of the present invention, the anodic oxide film corresponding to each of the pixel electrodes is colored with any one of the three primary colors so that the anodic oxide film corresponding to each of the pixel electrodes is formed. A structure provided with a color filter function can be employed.

Since the anodic oxide film on the metal substrate corresponding to the pixel electrode formation position or the anodic oxide film on the pixel electrode also serves as a color filter, the color filter conventionally provided on the counter substrate can be omitted. In addition, since the metal substrate or pixel electrode has a light reflecting surface and a colored anodic oxide film is formed on the light reflecting surface, the color filter is more reflective than the conventional structure where the color filter is provided on the opposite substrate. The distance between the surface and the colored anodic oxide film is reduced, and a bright display with less color shift can be obtained.

In the reflection type liquid crystal display device of the present invention, at least the surface of the metal substrate on the liquid crystal layer side is made of Al, Mg,
It is possible to adopt a structure made of an alloy mainly composed of at least one of Ti and Be or each of these metal elements, and an insulating layer coated on the metal substrate made of an anodic oxide film of these metals or alloys. If these metal anodic oxide films are used, a uniform insulating layer can be formed on the metal substrate with good adhesion and insulating properties.

In these metals, if the substrate is made of Al, the specific gravity is about the same as that of glass.
Since it has a specific gravity of about 2.7 and is higher in strength than glass, if the strength is about the same as that of a glass substrate, a metal substrate having a thickness of about 1/2 to 1/3 of the thickness of the glass substrate is used. The substrate portion can be made thinner or lighter. The same applies to Mg, Ti, and Be. By using a substrate made of such a metal material instead of a glass substrate, the thickness and weight can be reduced.

An electronic apparatus according to the present invention includes the above-mentioned various reflection type liquid crystal display devices as a display section.
If the electronic device is provided with the above-described excellent reflection type liquid crystal display device, it is possible to promote a reduction in thickness, weight, and size, and obtain a display device with high display quality. Further, if the electronic apparatus is provided with the above-described excellent reflective liquid crystal display device, a structure in which the configuration of the color filter portion is simplified can be provided.

[0027]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment of a Reflective Liquid Crystal Display) A liquid crystal panel of a first embodiment of a reflective liquid crystal display according to the present invention will be described below with reference to FIGS.
FIG. 1 shows a reflection type TFD (Thin Film Diode) according to the present invention.
FIG. 2 is an exploded perspective view showing a first embodiment applied to a (type) liquid crystal panel, FIG. 2 is a cross-sectional view of the first embodiment, and FIG. 3 is an enlarged cross-sectional view of a pixel electrode portion of the first embodiment. FIG. 4 is an enlarged sectional view of a switching element portion according to the first embodiment.

By mounting auxiliary elements such as a liquid crystal driving IC and a support on the liquid crystal panel 10 of this embodiment, a reflection type liquid crystal display device as a final product is constituted.

The liquid crystal panel 10 of this embodiment has a pair of a rectangular transparent substrate 13 and a metal substrate 14 that are substantially rectangular in plan view and are attached to each other via an annular sealing member 12 so as to face each other. And the sealing material 1 between them.
The liquid crystal layer 15 is sandwiched between the liquid crystal layer 2 and a polarizing plate 16 provided on the upper surface side (observer side) of one of the transparent substrates 13. Of the substrates 13 and 14,
The transparent substrate 13 is made of transparent glass and is a front substrate provided to face the observer, and the metal substrate 14 is a thin substrate made of opaque metal provided on the opposite side, in other words, on the back side. In this embodiment, only one polarizing plate 16 is provided. However, it is needless to say that a required number of polarizing plates may be separately provided. In addition to the polarizing plate, a retardation plate or the like is also necessary. Needless to say, it may be provided accordingly.

The transparent substrate 13 has a thickness of, for example, 300 μm.
m (0.3 mm) glass substrate,
It may be equivalent to various glass substrates that have been widely used in reflection type liquid crystal display devices. In addition, the thickness of the transparent substrate 13 is an example,
Needless to say, a thinner glass substrate may be applied as appropriate. The back side of the transparent substrate 13 (in other words, the liquid crystal layer 15
An electrode 18 is formed on the (side) side. In an actual liquid crystal display device, an alignment film is provided on the liquid crystal layer 15 side to cover the electrodes 18..., But is omitted in FIG. Although an alignment film is also provided in FIGS. 1 and 2, the description is omitted in FIGS. 1 and 2 and the description of the alignment film is also omitted.

The liquid crystal driving electrode 18 on the liquid crystal layer 15 side of the substrate 13 is formed of a transparent conductive material such as ITO (Indium Tin Oxide: indium tin oxide) in a stripe shape in plan view.

On the other hand, in this embodiment, the metal substrate 14
It is made of at least one of l, Mg, Ti, and Be or an alloy mainly containing each of these metal elements, for example, any of Al alloy, Mg alloy, Ti alloy, Ag alloy, and Be alloy. Since the metal substrate 14 may be a laminated body, at least one of Al, Mg, Ti, Be or each of these metal elements is mainly formed on a thin metal plate having a high strength and a specific gravity as small as possible. It is a matter of course that a laminate having a coating layer of an alloy may be used.

Then, the upper surface of the metal substrate 14 (the liquid crystal layer 15
(A side surface) is subjected to a light diffusion process described below to form a light diffusion / reflection surface 14A.

The light diffusion process is a process for scattering the light reflected by the metal substrate 14 after passing through the liquid crystal layer 15, and the surface of the metal substrate 14 is plastically deformed by a plastic working tool such as a mold. A process of forming a large number of irregularities on the surface of the metal substrate 14, a process of forming irregularities on the surface of the metal substrate 14 by mechanical processing means such as mechanical cutting, and a process of applying a resist to the surface of the metal substrate 14 and etching the surface. Removal of necessary parts and removal of resist to process unevenness, processing such as sandblasting to spray abrasive grains for grinding, and surface roughening of metal substrate by electrolytic polishing This is a process performed by performing one or more methods. The metal substrate 14 that has been subjected to these treatments has irregularities, has a surface gloss, and diffusely reflects light, and thus can be used as a reflector of a reflective liquid crystal display device.

In the above-mentioned various methods, light can be scattered by dimple processing by cutting the surface of the metal substrate 14, light can be scattered by finish polishing, and a mixture of phosphoric acid and sulfuric acid can be obtained by acidic etching. Light scattering can also be performed by treating with a liquid at a treatment temperature of 105 to 120 ° C. for a necessary time. In addition, the light diffusion reflection surface can be formed by electropolishing. In this case, the basic methods include a perchloric acid acetic acid method, a phosphoric acid phosphoric acid method, a concentrated phosphoric acid method, a vibrating electric field polishing method, a fluoroborate method, and an alkaline method. Any method such as a phosphate method, a sulfuric acid bath method, and an alkali method may be used. Electropolishing is a method of anodizing a metal such as Al anodically under a predetermined condition in an electrolyte of an oxidizing agent.
In particular, it is possible to adopt an electroluminescent process performed at a relatively high temperature and a high current density. As a more specific method, a phosphoric acid bath method described in Japanese Patent No. 1288891 (20 to 60 A /
By applying (electrolysis at a current density of dm2 at a bath temperature of 50 to 70 ° C. for about 3 to 20 minutes), an electrolytically polished surface having irregularities can be easily obtained.

The irregularities on the surface of the metal substrate 14 subjected to the light diffusion treatment by these various methods have, for example, a surface roughness Ra of about 0.03 to 0.25 μm.

Further, in the structure of this embodiment, the metal substrate 14
Is coated with an anodic oxide film 25 having a thickness of about 1500 to 4000 angstroms on the upper surface side (the liquid crystal layer 15 side). Here, if the anodic oxide film of Al is made of an anodic oxide film using sulfuric acid as an electrolyte,
Since a colorless and transparent material having good adhesion to the metal substrate 14 can be easily obtained, there is no adverse effect on the light reflection / scattering performance of the metal substrate 14. If an anodic oxide film of Al is used as this anodic oxide film, the Al is sulfuric acid 10 to 30.
% Immersion in a solution having a voltage of about 15 V to 50 V to obtain a pseudo γ film. In addition,
AA standard 1070 alloy, 11
A colorless and transparent anodic oxide film can be obtained from alloys 00, 3004, 5052, 5005, and 7072. The color changes under electrolysis conditions such as current density and bath temperature when an anodic oxide film is formed using these alloys, but the bath temperature is about 15 to 25 ° C and the current density is 60 to
A colorless and transparent anodic oxide film can be easily obtained under the condition of about 300 A / m3. The anodic oxide film is excellent in electrical insulation and has a volume resistivity of about 5 × 10 12 Ω · cm.

When the anodic oxide film 25 is formed on an alloy containing 0.5 to 2.0% of Mg in Al, the light reflectance is reduced according to the thickness of the anodic oxide film 25. The decrease in light reflectance is 5% when the thickness of the anodic oxide film 25 is 2 μm and 10% when the thickness of the anodic oxide film 25 is 10 μm. If the thickness of the anodic oxide film is in the above range (from 1500 to 4000 angstroms: at most 0.4 μm), there is no adverse effect even from the viewpoint of (1).

Next, in order to color the anodic oxide film 25, the following three methods can be mainly used.

One is to use the above-mentioned 10% to 30% sulfuric acid bath and apply a voltage of 15 to 50 V to a film thickness of 1500 to 400%.
A pseudo γ film of about 0 Å is produced. The anodic oxide film 25 formed under such conditions is, for example, as shown in FIG.
As shown in FIG. 5, the cell layer 25B has a structure including a nonporous barrier layer 25A and a porous cell layer 25B. The cell layer 25B has a large number of holes 25C which are vertically long in the thickness direction of the cell layer 25B. Structure. By injecting a dye of a desired color into a large number of holes 25C of such a cell layer 25B, the anodic oxide film 25 can be colored in a desired color, and after coloring, the holes 25C are sealed. By forming the sealing portion 25D, the colored anodic oxide film 25 having the cross-sectional structure shown in FIG. 3 is obtained. The sealing treatment can be performed by boiling with hot water or exposing to hot steam after the formation of the anodic oxide film.

In the structure of this embodiment, the anodic oxide film 25
Is partially colored, and the colored portion is colored in any of R (red), G (green), or B (blue) for each formation position of the pixel electrode 32 provided as described later. Is colored. In other words, when an electric field is applied to the liquid crystal layer 15 by the pixel electrode 32 to control the alignment of the liquid crystal molecules to switch display, non-display, or gradation, the anodic oxide film 25 corresponds to a pixel serving as one display unit. Is 3
Colored by primary color.

The portions corresponding to the pixel electrodes 32...
The first method of coloring by coloring into any one of (red), G (green), or B (blue) uses a photolithography process to open only a part to be colored in one specific color. ,
A first resist that covers other parts is applied, and a part to be colored is colored with one of the three primary colors. Then, the first resist is peeled off, and another specific one color is again applied. A second resist is applied so as to open a portion to be colored, and a second resist is applied to cover the other portion to color the required colored portion with another color, the second resist is peeled off, and finally, the remaining resist is removed. A part to be colored one color is opened, and a third resist is applied so as to cover the other part, and the remaining one color is colored.
A method of removing the resist may be performed.

Since the holes 25C... Of the cell layer 25B need to be closed after coloring, a sealing process is performed after coloring to seal the holes 25C to form a sealing portion 25D. deep.

A second method for coloring the anodic oxide film 25 is a method using an electrolytic coloring method. Al
(NH4) 2
It can be colored by AC electrolysis at 25 V in an electrolytic bath having 30 g / l of SO4 and 2 g / l of CuSO4. To color blue, a [K3Fe (CN) 6] electrolytic bath may be used. For coloring red, an electrolytic bath containing 7 g / l of H2 SO4 and 20 g / l of CuSO4 may be used. A resist covering the part other than the part to be colored is applied and formed, and only the necessary part is subjected to electrolytic coloring.
Can be partially colored.

A third method for coloring the anodic oxide film 25 is as follows: a 20 to 50% phosphoric acid solution;
After forming a pseudo-γ film at about 60 V and forming a cell layer,
Perform secondary electrolysis, cover the necessary parts with the previous resist,
A method of electrodepositing any one of R (red), G (green), and B (blue) pigments in the pores of the cell layer using a method of electrolytically treating only a necessary portion can be adopted.

Anodized film 2 colored by these methods
The surface of No. 5 may be subjected to a polishing process or the like, to provide a flatness and a gloss.

Next, on the upper side of the anodic oxide film 25 (on the side of the liquid crystal layer 15), a TFD type switching element and a pixel electrode described below are formed.

The data lines 30 are formed on the anodic oxide film 25 in a direction perpendicular to the stripe-shaped electrodes 18 at predetermined intervals and are arranged between the data lines 30. A plurality of pixel electrodes 32 made of a transparent conductive material such as ITO are formed via a two-terminal non-linear element 31 so as to be aligned. In this embodiment, the two-terminal linear element 31 is composed of a wiring element portion 33 drawn from the data line 30 such as Ta and a conductive film 34 such as Cr formed by partially overlapping the wiring element portion 33. And a connection portion of the pixel electrode 32 formed by partially overlapping the conductive film 34. As a two-terminal nonlinear element, as shown in the second example in FIG.
T formed by partially overlapping the wiring element portion 33 made of
a first conductive film 35 made of Cr or the like, a second conductive film 34 ′ made of Cr or the like formed by partially overlapping the first conductive film 35, An element structure including a connection portion of the pixel electrode 32 formed by overlapping portions may be employed.

The liquid crystal panel 10 according to the first embodiment described above
According to the description, after passing through the substrate 13 and the liquid crystal layer 15, the incident light L1 passes through the anodic oxide film 25 colored in any one of R (red), G (green), and B (blue). Is diffusely reflected by the light diffusion / reflection surface 14A on the surface of the metal substrate 14, passes through the colored portion of the anodic oxide film 25 and the liquid crystal layer 15 again, is emitted from the liquid crystal panel 10 through the polarizing plate 16, and is observed as emitted light L2. Reaches the naked eye E of the person. Then, by adjusting the voltage applied to the electrodes 18 and 32, the alignment of the liquid crystal molecules in the liquid crystal layer 15 is controlled, and the liquid crystal layer 1 is controlled.
5 is switched between display and non-display by adjusting the light transmission state. Further, since the anodic oxide film 25 is classified into three primary colors of R (red), G (green) and B (blue), a color display can be obtained.

In the liquid crystal panel 10 of the first embodiment, the substrate on the back side as viewed from the observer is formed of the metal substrate 14, which is thinner than the conventional glass substrate. It is lighter and thinner than the liquid crystal panel having the conventional structure. In the case of a normal glass substrate, the specific gravity is 2.5 to 2.7.
If the metal substrate is Al, the specific gravity of Al is 2.7.
Considering that the strength of Al is several times the strength of glass, it is clear that an Al substrate can be made thinner in order to obtain a substrate of the same strength, and in addition to Al, the specific gravity is smaller. If Mg (specific gravity: 1.7) is selected as the substrate constituent material, the substrate can be further reduced in weight.

Further, the surface of the metal substrate 14 is a light diffusion / reflection surface 14A having an uneven portion and is coated with an anodic oxide film 25 having an appropriate thickness. Since the reflected light can be irregularly reflected without deteriorating the high light reflectivity, a uniform, bright, high-quality display can be obtained without causing light unevenness such as interference light. Further, since the light diffusion / reflection surface 14A and the anodic oxide film 25 for color display are formed very close to each other, unlike the conventional structure in which a color filter is provided on the glass substrate 13 side on the opposite side. The problem of color misregistration is unlikely to occur.

(Second Embodiment of Reflective Liquid Crystal Display) FIG. 6 is a sectional view showing a liquid crystal panel 36 of a second embodiment of the reflective liquid crystal display according to the present invention.

Since the liquid crystal panel 36 of this embodiment has a structure obtained by partially changing the structure of the liquid crystal panel 10 of the first embodiment, the same components as those of the liquid crystal panel 10 are denoted by the same reference numerals. The description will be simplified.

In the liquid crystal panel 36 of the second embodiment, the pixel electrodes 37 are formed of metal electrodes. The material forming the pixel electrodes 37... Made of metal electrodes is made of the same material as the metal substrate 14 described above. Specifically, A
It is made of at least one of l, Mg, Ti, and Be or an alloy mainly containing each of these metal elements, for example, any of Al alloy, Mg alloy, Ti alloy, Ag alloy, and Be alloy.

The surfaces of the pixel electrodes 37... On the liquid crystal layer 15 side are subjected to light diffusion processing equivalent to that performed on the metal substrate 14 to form a light diffusion surface 37A.

Further, an anodic oxide film 37B is formed on the surface of the light diffusion surface 37A on the liquid crystal layer 15 side, and these anodic oxide films 37B are different from the structure of the anodic oxide film 25 of the structure of the first embodiment. Similarly, the three primary colors R (red) and G
(Green) or B (blue).

The upper surface side of the metal substrate 14 (the liquid crystal layer 15
Side) is subjected to light diffusion processing to form a light diffusion / reflection surface 14A.
Are formed, but the anodic oxide film 25 'formed thereon is not colored.

The liquid crystal panel 36 of the second embodiment described above
According to the method, after passing through the substrate 13 and the liquid crystal layer 15, the incident light L1 passes through the portion of the anodic oxide film 37 colored in any one of R (red), G (green), and B (blue). Is diffusely reflected by the light diffusion / reflection surface 37A on the surface of the metal pixel electrode 37, passes through the colored portion of the anodic oxide film 37B and the liquid crystal layer 15 again, is emitted from the liquid crystal panel 36 via the polarizing plate 16, and is emitted light L2 To the observer's naked eye E. Then, by adjusting the voltage applied to the electrodes 18 and 37, the alignment of the liquid crystal molecules in the liquid crystal layer 15 is controlled,
Display and non-display are switched by adjusting the light transmission state of the liquid crystal layer 15. The anodic oxide film 37B has R (red), G
Since the colors are classified into three primary colors (green) and B (blue), a color display can be obtained.

The other effects are the same as the effects obtained in the first embodiment. For example, the effects of thinning, lightening, and miniaturization by using the metal substrate 14 are equivalent to the first embodiment, and the effect that the problem of color misregistration hardly occurs is also equivalent to the first embodiment. is there.

In addition, in the structure of the second embodiment, the surface of the metal substrate 14 on the liquid crystal layer 15 side is
4A, the reflected light from the light diffusing / reflecting surface 14A can be used in addition to the light reflected from the light diffusing / reflecting surface 37A of the pixel electrode 37, and the uniformity can be achieved without causing light unevenness such as interference light. It is possible to obtain an even brighter high-quality display.

In the second embodiment, the entire pixel electrode 37 is a metal electrode. However, if only the upper surface of the pixel electrode 37 is made of metal, the object can be achieved.
The bottom side of the pixel electrode 37 may be formed of a transparent conductive material such as ITO, and a pixel electrode having a double structure in which a metal layer is formed thereon may be used.

(Third Embodiment of a Reflective Liquid Crystal Display) FIG. 7 is a sectional view showing a liquid crystal panel 40 of a third embodiment of the reflective liquid crystal display according to the present invention.

The liquid crystal panel 40 of this embodiment is a reflection type having one polarizing plate 16 like the liquid crystal panel 10 of the first embodiment described above with reference to FIGS.
The electrodes for driving the liquid crystal are of a simple matrix type.
However, since other basic structures are the same as those of the first embodiment or the second embodiment, the same components are denoted by the same reference numerals, and the description of those components will be omitted. Will be described.

The liquid crystal panel 40 of the present embodiment comprises a metal substrate 14 on the back side of which a light diffusion process has been performed, similarly to the structure of the first embodiment. An anodic oxide film 25 'is formed on the light diffusion / reflection surface 14A of the metal substrate 14, and a stripe-shaped pixel electrode extends in a direction perpendicular to the stripe-shaped electrode 18 on the transparent substrate 13 side on the viewer side. 41 are formed at regular intervals.

The liquid crystal panel 40 according to the second embodiment is different from the liquid crystal panel 10 according to the first embodiment in the driving method for driving the liquid crystal. However, the voltage applied to the electrodes 18 and 41 and the timing thereof are adjusted. The control of the orientation of the liquid crystal molecules located between the intersections of the electrodes 18 and 41 is performed by controlling the light transmission state of the liquid crystal layer 15 to switch between display and non-display.

The liquid crystal panel 40 according to the second embodiment can obtain the same effect as the liquid crystal panel 36 according to the second embodiment. That is, the liquid crystal panel 40 shown in FIG. 7 can be made thinner, lighter, and smaller. Further, it is possible to obtain a uniform, bright, high-quality display without causing light unevenness such as interference light.

(Fourth Embodiment of Reflective Liquid Crystal Display) FIG. 8 is a sectional view showing a liquid crystal panel 50 of a fourth embodiment of the reflective liquid crystal display according to the present invention.

The liquid crystal panel 50 of this embodiment is a reflection type having one polarizing plate 16 like the liquid crystal panel 10 of the first embodiment described above with reference to FIGS.
The switching element for driving the pixel electrode 32 is constituted by a thin film transistor T. However, since other basic structures are the same as those of the first embodiment, the same components are denoted by the same reference numerals, and the description of those components is omitted. The following mainly describes different components.

The thin film transistor T as a switching element is formed by forming scanning lines 51 in a matrix on an anodic oxide film 25 (having R, G, B colored portions) as an insulating layer formed on a metal substrate 24. A signal line 52 is formed, and a pixel electrode 52 is provided for each region surrounded by the scanning line 51 and the signal line 52. A corner portion of each pixel electrode 52, the scanning line 51, the signal line 52, A thin film transistor having a source electrode 53, a drain electrode 54, a semiconductor 55, and a gate electrode 56 is incorporated in a portion between them, and the thin film transistor T is turned on / off by applying a signal to the scanning line 51 and the signal line 52. Pixel electrode 5
2 can be controlled. Further, in this embodiment, the electrode 57 formed on the transparent substrate 13 on the opposite side is a full-surface electrode covering the entire pixel electrode formation region.

In the liquid crystal panel 50 of the present embodiment, the back substrate is formed of the metal substrate 14 as in the structure of the first embodiment. The anodic oxide film 2 is formed on the metal substrate 14.
5 are formed.

The liquid crystal panel 50 of the fourth embodiment is different from the liquid crystal panel 10 of the first embodiment in the configuration of the switching elements. However, by adjusting the voltage applied to the electrodes 57 and 52, the orientation of the liquid crystal molecules is adjusted. Control the liquid crystal layer 15
Switching between display and non-display by adjusting the transmission state of light is the same.

The liquid crystal panel 50 of the fourth embodiment can obtain the same effects as those of the liquid crystal panel 10 of the first embodiment. That is, in the liquid crystal panel 50 shown in FIG. 8, since the metal substrate 14 is used, a reduction in thickness, weight, and size can be realized. In the structure of the fourth embodiment, the metal substrate 1
Since the light can be diffusely reflected on the light diffusion / reflection surface 14A on the upper surface of the display 4, a uniform, bright, high-quality display can be obtained without generating light unevenness such as interference light.

(Embodiment of Electronic Apparatus) Next, the liquid crystal panels 10, 36, 4 of the first, second and third embodiments will be described.
A specific example of an electronic device provided with either 0 or 50 will be described.

FIG. 9A is a perspective view showing an example of a mobile phone.

In FIG. 9A, reference numeral 200 denotes a main body of the mobile phone, and reference numeral 201 denotes the liquid crystal panels 10 and 3.
6 shows a liquid crystal display unit using any one of 6, 40, and 50.

FIG. 9B is a perspective view showing an example of a portable information processing device such as a word processor or a personal computer.

In FIG. 9B, reference numeral 300 denotes an information processing device, reference numeral 301 denotes an input unit such as a keyboard, and reference numeral 3 denotes an input unit.
Reference numeral 03 denotes an information processing apparatus main body, and reference numeral 302 denotes a liquid crystal display unit using any one of the liquid crystal panels 10, 36, 40, and 50.

FIG. 9C is a perspective view showing an example of a wristwatch-type electronic device.

In FIG. 9C, reference numeral 400 denotes a watch main body, and reference numeral 401 denotes the liquid crystal panels 10, 36,
A liquid crystal display unit using any one of 40 and 50 is shown.

Each of the electronic devices shown in FIGS. 9A to 9C includes a liquid crystal display unit using any one of the liquid crystal panels 10, 40, and 50. Reflection type liquid crystal display devices 10, 36, 40, 5 of the fourth embodiment
Since the reflective liquid crystal display device has the feature of No. 0, the electronic device can be made thinner, smaller, and lighter, and has an excellent effect of bright display quality, using any of the reflective liquid crystal display devices.

[0082]

As described above, according to the liquid crystal device of the present invention, since a metal substrate is used as one of the substrates sandwiching the liquid crystal layer, a metal thinner than the glass substrate even if having the same strength as the glass substrate. A substrate can be used, and it can be made thinner, lighter, and smaller than a reflective liquid crystal display device having a conventional structure using a glass substrate. Next, since the surface of the metal substrate on the liquid crystal side is a direct reflection surface capable of diffusing light, the reflection efficiency is good, and a bright high-quality display can be obtained.

At least the surface of the metal substrate preferably has A
If the substrate is made of l, the specific gravity is about the same as glass,
For example, it has a specific gravity of about 2.7 and strength is higher than glass, so if the strength is about the same as a glass substrate,
A metal substrate having a thickness of about 1/2 to 1/3 of the thickness of the glass substrate can be employed, and the substrate portion can be made thinner or lighter. The same applies to Mg, Ti, and Be. By using a substrate having at least a surface made of such a metal material instead of a glass substrate, a reduction in thickness, weight, and size can be achieved.

Further, in the present invention, the anodic oxide film on the metal substrate or the metal electrode is colored in three primary colors and provided with a color filter function, so that the color filter conventionally provided separately on the counter substrate side can be eliminated. In both cases, color display is possible. And, by having a color filter function on the anodic oxide film on the metal substrate or the metal electrode, an anodic oxide film having a color filter function is provided immediately above the light reflection surface, so that color shift is less likely to occur and high display quality is obtained. A bright display can be obtained.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a liquid crystal panel according to a first embodiment of the present invention.

FIG. 2 is a sectional view of the liquid crystal panel of the first embodiment.

FIG. 3 is an enlarged sectional view of an anodic oxide film on a metal substrate provided in the liquid crystal panel.

FIG. 4 is a sectional view showing a structure of a connection portion between a pixel electrode and a two-terminal linear element of the liquid crystal panel according to the first embodiment of the present invention.

FIG. 5 is a plan view showing a second example of a two-terminal linear element used in the liquid crystal panel according to the present invention.

FIG. 6 is a sectional view of a liquid crystal panel according to a second embodiment of the present invention.

FIG. 7 is a sectional view of a liquid crystal panel according to a third embodiment of the present invention.

FIG. 8 is a sectional view of a liquid crystal panel according to a fourth embodiment of the present invention.

9A and 9B show application examples of the electronic apparatus of the present invention. FIG. 9A is a perspective view showing a portable telephone, and FIG. 9B is a perspective view showing an example of a portable information processing device. FIG. 9C is a perspective view showing an example of a wristwatch-type electronic device.

FIG. 10 is a sectional view showing an example of a conventional reflection type liquid crystal display device.

[Explanation of symbols]

 10, 36, 40, 50: Liquid crystal panel 13: Transparent substrate 14: Metal substrate 14A, 37A: Light reflection / diffusion surface 15: Liquid crystal layer 18, 32, 37 ... Electrode 25, 25 ': Anodized film 25A: Barrier layer 25B ... Cell layer 25D ... Sealing part 31 ... Switching element of two-terminal linear element T ... Thin film transistor 200 ... Mobile phone main body 300 ... Portable information processing device 400 ... Watch type electronic device

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H048 BA02 BA15 BA19 BA20 BA24 BA62 BB02 BB12 BB43 BB44 2H091 FA14Y FA16Y FC01 FC05 FC06 FC28 GA01 GA02 GA07 GA13 LA11 2H092 HA05 JB07 MA11 MA24 NA01 PA01 PA08 5G435 AA03 BB03 GG12 HH02 HH12 LL07 LL09 LL10

Claims (11)

[Claims] 1. A liquid crystal layer is sandwiched between a metal substrate and a transparent substrate opposed to the metal substrate, and a reflection surface having an uneven portion is formed on a surface of the metal substrate on the liquid crystal layer side to form a light source. A reflection diffusion surface is formed, an anodic oxide film is coated on the light reflection diffusion surface, and a plurality of transparent pixel electrodes for driving liquid crystal are formed on the absolute anodic oxide film. A reflective liquid crystal display device, wherein an electrode on the opposite side is formed on the liquid crystal layer side of the transparent substrate while the anodized film is colored. 2. A liquid crystal layer is sandwiched between a pair of substrates, a plurality of pixel electrodes for driving liquid crystal are formed on the one substrate, and a counter electrode for driving liquid crystal is disposed on the other substrate to face the pixel electrodes. Side electrode is formed, at least a liquid crystal layer side surface of the pixel electrode is made of a light-reflective metal electrode, and an anodic oxide film is formed on the liquid crystal layer side surface of the metal electrode, and the anode A reflective liquid crystal display device characterized in that the oxide film is colored. 3. The reflection substrate according to claim 2, wherein, of the pair of substrates, a substrate on which a pixel electrode is formed is formed of a metal substrate, and an insulating layer is formed on the metal substrate. Liquid crystal display device. 4. A light reflecting / diffusing surface is formed by forming a reflecting surface having irregularities on a surface of the metal substrate on a liquid crystal layer side, and an insulating layer is coated on the light reflecting / diffusing surface. 4. The reflection type liquid crystal display device according to claim 3, wherein a pixel electrode is formed on the reflection type liquid crystal display device. 5. The method according to claim 1, wherein the anodized film comprises a non-porous barrier layer and a porous cell layer, and a dye is injected into the pores of the cell layer to color the anodized film. The reflective liquid crystal display device according to claim 1, 2, 3, or 4. 6. The reflection type liquid crystal display device according to claim 1, wherein said anodized film is colored by electrodeposition with a pigment. 7. The method according to claim 1, wherein the coloring of the anodic oxide film is performed by electrolytic coloring.
5. The reflective liquid crystal display device according to 2, 3, or 4. 8. An anodic oxide film corresponding to each of said pixel electrodes is colored in any one of three primary colors, and a color filter function is provided to an anodic oxide film corresponding to each of said pixel electrodes. The reflective liquid crystal display device according to claim 1. 9. The method according to claim 1, wherein the metal substrate or the metal electrode is Al,
9. The reflection type liquid crystal display device according to claim 1, wherein the reflection type liquid crystal display device is made of an alloy mainly composed of at least one of Mg, Ti, and Be or each of these metal elements. 10. The reflection according to claim 1, wherein a switching element formed of a two-terminal linear element or a thin film transistor is formed together with the pixel electrode on the other substrate. Liquid crystal display device. 11. An electronic apparatus comprising the reflective liquid crystal display device according to claim 1 as a display unit.