JPH0990351A - Production of reflection type liquid crystal display element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a bright reflection type liquid crystal display element having a high use efficiency of light and a high contrast ratio. SOLUTION: This element has a liquid crystal compsn. 15 held between two electrode substrates 11, 12 disposed in the observer side and the counter side. The element has a modulating part (A) where the liquid crystal compsn. responds to electric signals from electrodes to modulate the degree of reflection for the incident light, and a non-modulating part (B) except for the modulating part (A). A white reflection layer 20 is formed in the area of the non-modulating part (B) on the substrate 11. The white reflection layer 20 consists of, for example, a resist material with dispersion of a TiO2 white pigment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a reflective liquid crystal display device.

[0002]

2. Description of the Related Art A liquid crystal display element (hereinafter abbreviated as LCD) is a word processor, a personal computer, a projection type T
Widely used for V, small TV, etc.

In recent years, a reflective LCD that does not require a backlight has been receiving attention. The reflective LCD does not require a backlight for displaying on an OA device or the like, and thus can reduce power consumption and is suitable for portable use. The reflective LCD is
Since the light of the outside light is used, it poses a practical problem unless the reflectance of the LCD itself is high.

When the reflective LCD is classified from the viewpoint of the reflectance of the LCD itself, a display mode using two polarizing plates,
It can be classified into three display modes, one using a sheet and one not using it.

As a display mode using two polarizing plates,
For example, the TN type LCD shown in FIG.
Reference numeral 2 has transparent electrodes 3 and 4, respectively, and a liquid crystal composition layer is sandwiched between these substrates. Polarizing plates 61 and 62 are attached to the outer surfaces of the upper and lower substrates 1 and 2, and the polarizing plate 62 on the lower substrate 2 side is attached.
It has a structure in which a diffuse reflection plate 7 is attached to the outer surface, and the optical path L of this TN LCD passes through the polarizing plate four times and through the substrate four times. Among these transmittances, the transmittance of the polarizing plate is 50% or less in principle at least once, and is actually 40% or more. Since other polarizing plates and substrates also have their own absorption, the reflectance is extremely low.

As a display mode using one polarizing plate,
For example, a polarizing plate single mode ECB type LCD having only the polarizing plate 61 shown in FIG. 21, which is the TN type LCD of FIG.
In comparison with the optical path, the polarizing plate only passes twice and the substrate passes only twice. Note that, in the following drawings, the same reference numerals denote the same parts. As in the case of the TN LCD, the transmittance of the polarizing plate is 50% or less in principle at least once, and is actually 40% or more. However, in terms of the optical path, it is possible to reduce the light absorption for two polarizing plates and two substrates, so that the TN
The reflectance is slightly higher than that of the type LCD.

In comparison with these, a display mode not using a polarizing plate is, for example, a polymer polymer PC-GH type LCD having a liquid crystal composition layer 51 of a guest-host liquid crystal shown in FIG.
GH having guest-host liquid crystal composition layer 52 shown in FIG.
A HOMO type LCD and a two-layer guest-host liquid crystal composition layer 52 shown in FIG.
There is a layer type GH-HOMO type LCD and the like. Since neither method uses a polarizing plate, in principle, when the transmittance is at least once as in the display mode using the polarizing plate described above,
It is 0% or less, and it is bright because it does not use a polarizing plate, which is actually 40%. Further, if the reflection plate is provided on the inner surface of the cell as in the case of the one-polarizing plate mode ECB type LCD, the light absorption for two times of the substrate can be reduced. Therefore, the reflectance is significantly higher than that in the display mode using the polarizing plate.

Further, the reflection type LCD shown in FIG. 25 is shown in FIG.
In the GH-HOMO LCD shown in FIG. 1, a quarter wave plate 9 is inserted between the reflection plate 7 and the liquid crystal cell, and incident light passing through the liquid crystal cell passes through the quarter wave plate 9. The light is reflected by the reflection plate 7 and transmitted through the quarter-wave plate 9 again, so that the phase is shifted by a half wavelength and the function of entering the liquid crystal cell again is obtained.

This structure has a two-layer type GH-HO shown in FIG.
The same light control as that of the MO type LCD is obtained by a single liquid crystal layer and a single liquid crystal cell.

Now, these reflection type LCDs are displays, and generally display is performed by applying voltage to the liquid crystal layer, flowing current, or applying magnetic field, using electrodes. Since electrodes are used, an insulating region (a place without electrodes) is always required. In particular, in the case of an element that displays various characters, pictures, images, and other patterns, electrodes are formed in a matrix. When electrodes are formed in a matrix, wiring is generally required in addition to the electrodes for the purpose of applying a voltage to the liquid crystal layer. Even if the electrodes are not formed in the matrix, if the pattern is complicated to some extent (for example, 7-segment display applied to calculators, watches, etc.), wiring is required. As described above, the LCD is formed by three regions of an electrode and an insulating region (where there is no electrode) for the purpose of applying a voltage to the liquid crystal layer, and a wiring in some cases.

In the present invention, a region in which the liquid crystal responds by an electrode for the purpose of applying a voltage to the liquid crystal layer and the amount of light reflection is modulated is called a modulation part, and the other region is called a non-modulation part. In the non-modulation section, the insulating area is referred to as a space section, and the area where the wiring is provided is referred to as a wiring section.

Incidentally, in a transmissive LCD, a light shielding layer is often provided in the non-modulation portion. In the case of a matrix display element, this light shielding layer is generally a black matrix (B
M). This light shielding layer is provided for the purpose of improving the contrast ratio characteristic of display. LC
When the display mode of D is classified from the viewpoint of display control (not limited to the transmissive type and the reflective type), it is applied in the opposite manner to the normally white mode (referred to as NW mode) in which a bright state is obtained in the absence of voltage application. It can be roughly classified into a normally black mode (referred to as NB mode) in which a bright state is obtained. In the NW mode, the non-modulation section is almost always in the bright state regardless of the state of the modulation section. Therefore, in the case where the light shielding layer is not provided, the luminance in the dark state as a whole (modulation portion and non-modulation portion) is higher than that in the case where the light shielding layer is provided. Therefore, the contrast ratio (brightness in the bright state / luminance in the dark state) is improved by providing the light shielding layer. In the NB mode, the non-modulation section is almost always in the dark state regardless of the state of the modulation section. Therefore, as compared with the NW mode, the brightness in the dark state as a whole (modulation section and non-modulation section) becomes darker. However, in the generally known dark state of the NB mode, a sufficiently dark display is not obtained. Therefore, by providing the light-shielding layer, the brightness of the non-modulation portion is surely reduced to zero and a high contrast is obtained. However, the provision of this light shielding layer lowers the overall display brightness (brightness). Although this is a drawback, in the case of a transmissive LCD, since a backlight is used, display brightness (brightness) can be maintained by improving the brightness of this backlight. Thus, a light-shielding layer is often provided to obtain contrast.

On the other hand, in the reflective LCD, the light used is external light, and the amount of incident light cannot be controlled on the display side. Therefore, when the light-shielding layer is applied to the reflective type, the display brightness is significantly lowered, and thus it is not generally used (T which has an influence of light as a driving element).
For the purpose of preventing the influence of FT and the like, a light shielding layer may be provided only in a necessary portion of the non-modulation portion. ). In the first place, in the case of a reflective LCD, the light used is external light, and the amount of incident light cannot be controlled on the display side. Therefore, the most important characteristic is brightness (luminance). For these reasons, the general conventional reflective LCD does not have a light-shielding layer in the non-modulation part.

However, even if the light-shielding layer is not provided, the display brightness of the conventional reflective LCD is not sufficiently bright. In the NW mode, since the non-modulation part is almost always in the bright state, the whole display brightness can be obtained to some extent. However, the reflective LCD uses the polarizing plate and the dye to obtain the dark state. Some light absorption is unavoidable even in the bright state. Therefore, as a result, sufficient brightness cannot be obtained. In the NB mode, the non-modulation section is almost always in the dark state, and the entire display brightness is naturally dark.

[0015]

As described above, the conventional reflection type liquid crystal display device, when used as a display,
The reflectance is low even in the non-modulation portion, and particularly in the normally black mode, the influence is remarkable, and the overall display brightness is significantly reduced. It is an object of the present invention to solve these problems and to obtain a method of manufacturing a reflective liquid crystal display device having a novel structure that raises the overall reflectance regardless of the normally black mode and the normally white mode.

[0016]

As a means for solving the above-mentioned problems, the present invention provides a method for producing a reflection type liquid crystal display device comprising a liquid crystal composition sandwiched between two substrates with electrodes, which is transparent. A step of depositing a transparent conductive layer on one of the substrate surfaces, and a step of depositing a resist film on the transparent conductive layer and removing the resist film leaving a portion to be an electrode pattern of the transparent conductive layer, A step of etching the transparent conductive layer using the resist film as a mask to form an electrode pattern by the transparent conductive layer, and a white layer in which a white pigment is mixed in the resist on the substrate surface while leaving the resist film on the electrode pattern. The step of depositing and exposing the white layer from the surface of the one transparent substrate opposite to the surface on which the electrode pattern is formed, using the transparent electrode and the resist film on the transparent electrode as a mask. And a step of removing the resist film and the white layer on the transparent electrode and forming a white reflective layer in all or a part of the area other than the electrode pattern. A method for manufacturing an element is obtained.

Further, in a method of manufacturing a reflective liquid crystal display device in which a liquid crystal composition is sandwiched between two substrates with electrodes, a step of depositing a transparent conductive layer on the surface of one transparent substrate, and the transparent layer. A step of depositing a resist film on a conductive layer and removing the resist film leaving a portion to be an electrode pattern of the transparent conductive layer, and etching the transparent conductive layer using the resist film as a mask and using it as a mask A step of removing the resist film to form an electrode pattern by a transparent conductive layer; a step of applying a white layer mixed with a white pigment to the resist on the substrate surface while leaving the resist film on the electrode pattern; A step of selectively exposing a region of the white layer other than the transparent electrode from the surface opposite to the electrode pattern forming surface of the transparent one substrate, and removing the white layer on the transparent electrode, It is intended to obtain a manufacturing method of a reflection type liquid crystal display element characterized by comprising a step of forming a white reflective layer on all or part of the region other than the electrode pattern.

Further, in a method of manufacturing a reflection type liquid crystal display device in which a liquid crystal composition is sandwiched between two substrates with electrodes having a color filter on one substrate, a colored layer is coated on one transparent substrate surface. And a step of depositing a resist film on the colored layer and removing the resist film leaving a portion of the colored layer to be a color filter, and etching and coloring the colored layer using the resist film as a mask. A step of forming a color filter pattern by layers,
The step of depositing a white layer in which a white pigment is mixed in a resist on the surface of the substrate having the color filter pattern, the step of exposing the white layer from the back surface of the transparent substrate, and the white layer on the color filter pattern. And a step of forming a white reflective layer on a region other than the colored layer, the method for producing a reflective liquid crystal display device.

Further, the present invention provides a method for manufacturing a reflection type liquid crystal display element, characterized in that a white reflective layer is formed in a region other than the pixel electrode and the wiring layer.

[0020]

The operation of the present invention will be described below with reference to the drawings.
This will be described in detail. In addition, in each figure, the part of the same code | symbol shows the same part.

The liquid crystal display device obtained by the manufacturing method of the present invention is related to the prior application Japanese Patent Application No. 6-251771. That is, this liquid crystal display element is characterized in that the white reflective layer is provided in a part or the whole of the substrate region of the non-modulation portion formed around the pixel electrode which is the light modulation portion.

The present invention is characterized by a method of manufacturing such a reflective liquid crystal display element, in which a white reflective layer is applied to a substrate by using a backside exposure means.

Here, the white reflective layer means a layer which is diffusely reflected with a reflectance substantially higher than that of the reflection of the pixel electrode portion which is the light modulation portion, and specifically, a white pigment or a pigment having a power close to white. A resist material such as photoresist is used as a binder for a pigment such as a material in which a white pigment and a colored pigment are mixed.

FIG. 1 illustrates a cell structure in which the white reflective layer is provided in a part or the whole of the non-modulation section. That is, the upper substrate 11 on the observation side has the white reflective layer 20 and the stripe-shaped transparent electrode 13 on the inner surface thereof, and the lower substrate 12 which is the counter substrate is on the surface of the MIM switching element 1.
A large number of pixel electrodes 14 having 8 are arranged. Alignment films 16 and 17 are formed on the electrode side surfaces of both substrates, and a liquid crystal layer 15 is sandwiched between the substrates. Further, a diffuse reflection plate 30 is attached to the outer surface of the lower substrate 12, and the reflection type liquid crystal display element 10
Is configured.

The electrode region is a region where the liquid crystal responds to the applied voltage and modulates the amount of light reflection, and constitutes the modulator A. The other part is a region where the light reflection amount cannot be controlled and constitutes the non-modulation part B. The non-modulation section B is an area occupied by a space section 21 which is a gap between electrodes and a wiring section 22 which operates the electrodes 13. The white reflective layer 20 is provided between the striped electrodes 13 on the inner surface of the upper substrate of the non-modulation portion B. The white reflective layer 20 is, for example, a white pigment whose main component is MgO, and it is desirable that the white reflective layer 20 exhibit a reflection characteristic close to so-called perfect diffuse reflection. The perfect diffuse reflection refers to a reflection characteristic in which the reflected light Lr is uniformly reflected at various angles regardless of the incident angle of the incident light Li, regardless of the environment (distance of incident light depending on the direction). It refers to the reflection characteristic that obtains high brightness even at various angles. That is, the white reflective layer used in a part or the whole of the non-modulation part of the liquid crystal display element of the present invention is the non-modulation part of the conventional reflection type LCD (a light shielding layer is provided or nothing is provided (wiring or liquid crystal layer). Occupies the area))), a higher reflectance is obtained.

As described above, the most required performance of the reflective LCD is brightness, that is, reflectance. Conventionally, in a transmissive LCD, a light-shielding layer is provided in the non-modulation portion in order to improve the contrast ratio characteristic.
No measures have been taken to improve the brightness, that is, the reflectance characteristic. For this reason, the total reflectance of the modulated portion and the non-modulated portion was low. On the other hand, in the present invention, the non-modulation portion is provided with a white reflective layer having a significantly high reflectance,
The non-modulation section always obtains high reflection regardless of the state of the modulation section. Therefore, the overall reflectance is significantly improved as compared with the case where the white reflective layer is not provided.

As described above, the above-mentioned effect can be obtained by arranging the layer thickness and arrangement of the white reflective layer so as to obtain a reflectance higher than that of the non-modulation portion of the conventional reflective LCD. For example,
As shown in FIG. 2, when applied to a character display consisting of 7 segments 23 having a relatively large display pattern,
The white reflective layer 20 may be provided on the outer surface of the observation side substrate 11 of the non-modulation section B with a layer thickness that can obtain sufficient complete diffuse reflection characteristics. However, in the case where the display pattern is a high-definition pattern that is finer than the plate thickness of the substrate 11, it is desirable to provide the white reflective layer 20 on the inner surface of the substrate as shown in FIG. 1 in order to prevent parallax due to the substrate thickness.

As described above, the effect of the present invention can be obtained irrespective of the layer thickness by configuring the layer thickness and arrangement of the white reflective layer so as to obtain a higher reflectance than the non-modulation part of the conventional reflective LCD. Therefore, the layer thickness does not have to extend to the liquid crystal layer thickness (substrate gap), and in the case of the manufacturing method in which the white reflective layer is formed on one of the substrates in the substrate manufacturing step, light absorption in the liquid crystal layer is avoided. Therefore, it is better to provide it on the inner surface of the substrate on the observation side.
Especially, a dye-added reflective LCD with a large amount of light absorption in the liquid crystal layer
In the above, the effect of the above configuration is large, and in the NB mode which shows a dark state when no voltage is applied, the light absorption amount in the liquid crystal layer is extremely high, and therefore the effect is large.

When the present invention is applied to the matrix type LCD, the non-modulation section B is necessarily provided with wiring. Here, the wiring is a conductor provided for connecting the outside of the cell and the electrode of the modulation section in order to apply a voltage or the like to the modulation section. For example, in the case of an electrode structure having a simple matrix structure, as shown in FIG. 3A, among the electrode patterns in the region 24 forming one pixel, the upper and lower electrodes 13,
Conductor regions 131, 1 other than the intersection of 14 (modulation section A)
Refers to 41. In order to maximize the above-mentioned overall reflectance, the white reflective layer should be provided in the entire non-modulation section B in the display area in plan view.

However, as shown in FIG.
When using the matrix substrate 11 with the MIM element 18,
Generally, the wiring 22 has a light-shielding conductive material (for example, A
l) is used. In order to provide the white reflective layer 20 on the substrate so as to function over the entire non-modulation section B in the display area, a white reflective layer is provided under the wiring as described above. There must be. However, in order to provide the wiring as a lower layer, it is necessary to form the wiring layer 22 on the white reflective layer 20, and resistance to the white reflective layer material is required in the wiring pattern forming step. Therefore, in the matrix type LCD, as shown in FIG. 3B, the non-modulation part B in the display area is practically used.
Among the (regions other than the pixel electrode 13), only the region other than the wiring portion 22, that is, the space portion 21, has the white reflective layer 20.
With the structure provided with, it is not necessary to have resistance to the white reflective layer material in the wiring pattern forming step.

Needless to say, the white reflective layer used in the present invention can obtain the effect as long as strong diffuse reflection can be obtained. Alumina (aluminum oxide), the above-mentioned MgO (magnesium oxide), or the like can be applied as the material capable of obtaining such a strong diffuse reflection. Particularly, when a resist material in which a white pigment is dispersed is used as the material, the white reflective layer In the pattern forming step, the white reflective layer material itself can be formed simply by exposing and developing it. Therefore, the process can be simplified as compared with a material that requires etching after exposure and development using a resist material separately. As a material used for this white pigment, TiO2 is particularly excellent in terms of dispersibility. TiO2 is also particularly excellent when a resist material having a white pigment dispersed therein is used in the white reflective layer of the present invention.

When the present invention is applied to a reflection type LCD for displaying a color by using a color filter, a colored layer having substantially the same shape as the modulating portion is formed, and the white reflective layer is provided in a region other than the colored layer. In this case, it is possible to eliminate the surface step caused by the thickness of the colored layer by the white reflective layer. Further, when the white reflective layer is formed of a resist material in which a white pigment is dispersed, it is possible to perform patterning by back surface exposure using the colored layer itself as a photomask. Further, by providing the white reflective layer in the area other than the colored layer, in addition to the effect of improving the overall reflectance described above, the effect of preventing coloring of the non-modulated portion can be obtained.

The effect of the present invention can be obtained in various reflective LCDs. In particular, a method in which a dye is added to the liquid crystal layer (a guest-host (GH) type LCD is generally used because a dye is added to the liquid crystal material). Called)), the effect is great. The reason why the dye is added to the liquid crystal layer is that the degree of light absorption in the liquid crystal layer is high because the dye is added.

As described above, the GH type LCD shown in FIGS. 11 and 12 of the related art has a single liquid crystal layer (one cell), a high contrast ratio, and a display with a single liquid crystal layer. Since it has a function, the reflectance of the modulator is also high. Therefore, a black dye is used as the dye, and as the quarter wavelength plate, a quarter wavelength plate (for example, two different types) that can obtain a phase difference of a quarter wavelength of each wavelength with respect to the entire visible light wavelength range. It suffices to stack stretched films made of the above material by shifting the optical axis and combine the wavelength dependences of the respective retardations so that a quarter wavelength retardation can be obtained for all wavelengths. ), An extremely high contrast ratio and reflectance can be obtained in the modulator. In this display mode, the non-modulation section is always in the dark state regardless of the state of the modulation section. That is, it is the NB mode. Therefore, when the white reflective layer is provided on the non-modulation portion as in the present invention, the overall reflectance is significantly improved.

The structure shown in FIG. 3B has a substrate 11 on the observation side.
As a dot matrix substrate with MIM elements, a white reflective layer 20 is provided in a region other than the wiring portion and the modulation portion, that is, the entire space portion 21. In one configuration example of the present invention, the substrate 11 with the white reflective layer 20 is produced by the manufacturing method shown in FIG.

Step (I) M on one surface of the observation side substrate 11
The IM element 18 and the wiring 22 are formed.

Step (II) An indium tin oxide (ITO) film 13a is formed on the surface of the substrate by the sputtering method. A resist film 25a is deposited on the ITO film 13a by coating.

Step (III) The resist film 25a is exposed to ultraviolet UV through the mask pattern 26, and is developed while leaving only the resist film 23 on the ITO film which will be the pixel electrode 13 in a later step.

Step (IV) Next, using the resist film 25 as a mask, the ITO film 13a is etched to form an electrode pattern consisting of only pixel electrode portions.

Step (V) A resist film 20a mixed with TiO2 is applied to the entire surface of the substrate by coating.

Step (VI) The substrate 11 on which the pixel electrode 13 and the switching element 18 are formed and which is coated with the white layer 20a is irradiated with ultraviolet rays UV from the surface 11a on the opposite side, and the pixel electrode serving as a mask for this ultraviolet ray is irradiated. 13 and switching element 18 (and wiring layers such as address lines, data lines, storage capacitance lines) on layers 20a2 other than layer 20a1
Harden the part.

Step (VII) White layers 20a1, 20a on the uncured pixel electrode 13 and the switching element 18
2 and the resist film 25 on the pixel electrode is peeled and removed. As a result, the pixel electrode 13 and the switching element 1
The white reflective layer 20 is formed in a region other than the top 8, that is, in a portion excluding the switching element 18 and the wiring layer 22 in the non-modulation portion B.

As described above, the patterning of the wiring 22 and the pixel electrode 13 is performed by photolithography, and the resist used is a positive type (a resist of a type in which only the region irradiated with ultraviolet rays is removed in the developing process). ), And the resist material used for the white reflective layer is a negative type. The feature of the manufacturing method shown in FIG. 4 (a) is that the resist used in the pattern forming process of the wiring portion and the modulation portion is not peeled off, the material of the white reflective layer is applied thereon, and then the white layer is partially removed. Then, the white reflective layer is patterned in a region other than the wiring part and the modulation part by peeling the uncured white layer together with the resist used in the pattern forming step of the wiring part and the modulation part. You can

Partial curing of the white reflective layer by backside exposure has the effect of making the edge of the white reflective layer a smooth curved surface, as shown in FIG. 4 (b).

As shown in FIG. 4C, when the white reflective layer is provided only on the non-modulation portion, the resist film 25 as an electrode pattern forming mask is left only on the pixel electrode 13 and the entire surface is left. After applying a white layer to the white layer, the resist film is removed by the wrist-off method to remove the white layer on the electrode.
0a can be removed. However, the boundary edge that is in contact with the electrode 13 of the layer that remains in the non-modulation portion as the white reflective layer is the protrusion 2
Since 0b is formed, it becomes easy to form an undesired uneven surface on the substrate.

On the other hand, according to the present invention, since the above-mentioned wrist-off is not performed, the resist film on the electrode can be thin, and the edge of the white reflective layer in contact with the boundary of the electrode has a smooth curved surface. It is easy to ensure the uniformity of the gap between the substrates.

FIG. 5 shows another structural example of the present invention. The difference from the structural example shown in FIG. 4A is that the resist film 25 on the pixel electrode 13 is removed in the step (IV). Then, in step (V), a white layer is applied on the entire surface. In the figure, the parts having the same reference numerals indicate the same parts as in FIG. According to this step, since the resist film 25 does not cause the list-off, the white reflective layer can be thinned and the surface of the substrate having the electrode pattern can be made smooth. When the ITO electrode does not sufficiently function as a backside exposure mask, a mask 27 matching the pixel electrode is disposed on the surface side opposite to the surface of the substrate on which the white reflective layer is formed.

Although the manufacturing method of the present invention has been described above, the functions and effects of the present invention are not limited to these examples, and any structure and material that achieve the characteristics of the present invention can be used.
It goes without saying that similar actions and effects can be obtained. For example, as a substrate to be used, the same action and effect can be obtained with respect to a dot matrix substrate having a TFT element. Further, even if the white reflective layer is gray or slightly tinted, various materials can be used as long as they can obtain the reflectance in the bright state of the modulation section or the reflectance higher than that of the non-modulation section of the prior art, The present invention can also be applied to various types of liquid crystal display elements typically described as prior art.

[0049]

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

Example 1 FIGS. 7 to 10 show a liquid crystal display element of this example.

Two 0.7 mm thick glass substrates were used, and a pattern of the electrode 13 having the MIM element 18 as shown in FIGS. 7A and 7B was formed on the upper substrate 11 on one observation side. . FIG. 7A shows an electrode shape of one pixel, and each pixel has dimensions of 180 μm × 180 μm in length and width. FIG. 7B shows the shape of the effective display area of the upper substrate 11, in which the pixels are arranged in a matrix. 57.
The number of pixels of 480 × 320 is arranged within 6 mm × 86.4 mm.

As shown in FIG. 8, the upper substrate 11 on the observation side is M
The IM element 18, the wiring 22 and the transparent electrode 13 are formed, and the white reflective layer 20 is formed in the region excluding the transparent electrode 13 and the position of the non-modulation part B.

On the other hand, the lower substrate 12 on the opposite side is formed by arranging a plurality of stripe-shaped transparent electrodes 14 in parallel so as to correspond to the pixel electrodes. Alignment films 16 and 17 are deposited on these electrodes 13 and 14, and the liquid crystal composition layer 15 is sandwiched between the substrates.

In the manufacturing method of this embodiment, the first Ta layer 181 (the surface has a total film thickness of TaO2 of 1000 angstrom (hereinafter abbreviated as A)) is formed by oxidizing the surface on the upper substrate shown in FIG. 7 (a). Is formed in a pattern as shown in the drawing, and then the second Ta layer 22 (thickness 1000 A) is formed in a wiring pattern partially covering the first Ta film as shown in the drawing. An ITO film having a thickness of 2000 A is formed on the positive electrode and a positive resist material (O
FPR-5000, manufactured by Tokyo Ohka Co., Ltd. is applied to the entire surface, and calcination is performed at 60 ° C. for 30 minutes, followed by exposure using a mask so that a pixel electrode pattern can be formed.
After developing with a solution (manufactured by Tokyo Ohka Co., Ltd.) to form a structure in which the resist is coated only on the ITO film indicated by reference numeral 13 in FIG. 7A, hydrochloric acid / nitric acid aqueous solution (mixing ratio hydrochloric acid 10 / nitric acid 1. Etching was carried out with water 10).

Thereafter, without removing the resist, TiO 2 is formed on the entire surface of the effective display area 111 shown in the substrate of FIG. 7B.
Negative resist material in which 2 is dispersed (TiO2 dispersion:
A product of Nippon Synthetic Rubber Co., Ltd. was spin-coated to a film thickness of 1 μm and baked at 80 ° C. for 10 minutes. Next, back exposure was performed from the back surface of the substrate using the ITO film 13 serving as an electrode and the resist on the mask as a mask so that the negative resist material (white layer) in which TiO2 was dispersed was irradiated with light only at a desired place. After that, the developer JCR for negative resist material
The white layer was peeled off with CD-150CR (trade name, manufactured by Nippon Synthetic Rubber Co., Ltd.), and then the resist left only on the ITO film was peeled off with an ST10 solution (trade name, manufactured by Tokyo Ohka Co., Ltd.). . As a result, the white layer was patterned in the area of the non-modulation part other than the pixel electrode 13 in FIG. 7A in the effective display area of the substrate.

Next, in order to completely cure the white layer, the substrate is baked at 100 ° C. for 30 minutes, and white reflection is performed on the area other than the pixel electrode 13 and the switching element and the wiring portion in the effective display area when viewed from the back surface of the substrate. The layer 20 could be formed.

Further, as the substrate 12 to be opposed to the substrate shown in FIG.
ITO stripe pattern electrode 1 shown in (c) and (d)
A substrate on which No. 4 was formed was prepared. Here, FIG. 7C shows a pattern shape corresponding to one pixel, and FIG.
Indicates the shape of the effective display area 121.

On the two substrates thus obtained, the alignment film 1
Alignment agent (AL-1051, manufactured by Japan Synthetic Rubber Co., Ltd.) as Nos. 6 and 17 was printed on the effective display area and fired to obtain the ITO
Rubbing is performed in a direction parallel to the stripe pattern and opposite to each other by 180 ° between opposing substrates, and then a substrate gap material having a particle size of 5 μm (Micropearl SP, Sekisui Fine Chemical Co., Ltd.) is attached to the observation side substrate. Was applied at a spraying density of 100 / mm ^2, and a peripheral seal pattern having an opening with a width of 5 mm was formed around the effective display area of the counter substrate by a screen printing method. The seal material used here is a one-component epoxy resin (XN-21, manufactured by Mitsui Toatsu Chemicals, Inc.).

Next, the two substrates 11 and 12 are connected to the electrode 1
An empty cell used for the liquid crystal display device of the present embodiment by stacking them so that the 3rd and 14th surfaces face each other and baking at 180 ° C. for 2 hours while applying pressure so that the substrate gap becomes equal to the particle size of the substrate gap material. Got Thereafter, a nematic liquid crystal material ZL showing a positive dielectric anisotropy as a liquid crystal material in the empty cell.
A liquid crystal composition layer 15 was prepared by adding 2.0 wt% of black dye LA103 / 4 (manufactured by Mitsubishi Kasei Co., Ltd.) 152 to I-2293 (manufactured by Merck Japan Ltd.) 151 by a reduced pressure injection method. Then, the opening of the peripheral seal pattern was sealed with an ultraviolet curable resin UV-1000 (manufactured by Sony Chemical Co., Ltd.) to obtain a liquid crystal cell used in the liquid crystal display device of this example. Then, as shown in FIG. 8, a quarter-wave plate 31 and a reflector 30 were attached to each other to obtain a liquid crystal display element of this example. The reflection plate 30 used here is an M type diffusion reflection plate (manufactured by Nitto Denko Corporation), which is an Al vapor deposition type diffusion reflection plate, and the quarter-wave plate 31 is a laminated-type full-wavelength region of four minutes. 1 wavelength plate (manufactured by Nitto Denko Co., Ltd.), each with a paste.

As a structure, the liquid crystal display device of this embodiment has a white reflective layer 20 in the space portion of the viewing side substrate 11, and uses a white pigment resist material made of TiO2 as its material. This is based on the lift-off method using the resist pattern used in the ITO electrode pattern forming step. The liquid crystal display mode is a GH type using a liquid crystal composition to which a dye is added,
In addition, the display mode has the configuration shown in FIG. 9 in which a quarter-wave plate is added. That is, in the state where no voltage is applied, FIG.
As shown in, the unpolarized incident light Li passes through the liquid crystal composition layer 15, becomes linearly polarized light, becomes circularly polarized light at the quarter-wave plate 31, reaches the reflection plate 30, and is reflected as circularly polarized light again. Although passing through the quarter-wave plate 31, the direction of the linearly polarized light at this time is rotated by 90 ° with respect to the incident time, so that it is blocked by the liquid crystal composition layer 15 and the reflected light Lr is blocked. On the other hand, when a voltage is applied, as shown in FIG. 9B, the unpolarized light of the incident light Li is directly reflected and the reflected light Lr passes through the liquid crystal composition layer 15.

The reflectance and contrast ratio of the liquid crystal display element of this example obtained as described above were measured by the measuring device shown in FIG. For the measurement, a luminance meter 40 is arranged at a distance of 30 cm from the center of the sample in the direction of the normal line, and light is emitted at three wavelengths of red, green, and blue at approximately the same height in a direction forming an angle of 30 ° with the normal line. High color rendering fluorescent lamp 4
Two lamps 1 and 42 are arranged so that the illuminance of the sample 43 portion becomes 580 lux, and the standard diffuser plate (MgO
The brightness of the plate) is measured, and this brightness is set to 100% reflectance,
The reflectance and contrast of the sample were measured.

The results are shown in the table below (the same applies to the following examples).

[0063]

[Table 1]

By the way, the contrast ratio means a portion in the dark state (black portion) with respect to a portion in the bright state (white portion).
Is a parameter that indicates how distinctive it looks.
Consider the parameter of this contrast ratio in a reflective LCD that is configured to contribute the non-modulation part to the overall brightness as in the present invention. The actual contrast ratio that can be visually perceived is as follows. The brightness actually perceived in the case of the bright state portion is determined by the sum of the reflectances of the non-modulation section and the modulation section. This is because the brightness of the non-modulation part is brighter than that of the modulation part in the dark state, and as a result, the difference in brightness between the non-modulation part and the modulation part is
Relatively small. This is because the reflectances of the non-modulation section and the modulation section are mixed and are recognized by the eyes as a unit. On the other hand, as for the darkness that is actually visually perceived in the dark portion as in the dark state, only the darkness of the modulation portion is recognized. This is because the modulation part is darker than the non-modulation part, and as a result, the difference in brightness between the non-modulation part and the modulation part is not small as in the case of the bright state part. Therefore, they cannot be recognized by the eyes as a unit. Therefore, the darkness and blackness of the appearance are the darkness of the modulation part,
It depends heavily on blackness. Furthermore, as the non-modulation part is actually brighter, the darkness and blackness are more noticeable, so the darkness that is actually perceived in the dark part is darker as the brightness of the non-modulation part is brighter. You will be able to see it.

From the above, the contrast ratio CRL which is actually perceived in the reflection type LCD configured to contribute the non-modulation part to the overall brightness is defined by the equation (a) and evaluated. I decided to use it.

[0066]

[Equation 1]

In the dark state, the measurement diameter of the luminance meter was set to be less than the pixel modulation portion.

MI is applied so that the applied voltage to the liquid crystal layer becomes 4V.
The reflectance obtained by applying a voltage to the entire surface (all pixels) by using the M element is 80%, which is an extremely high value, and the entire surface (all pixels by using the MIM element so that the applied voltage to the liquid crystal layer is 0V and 4V). When a contrast ratio was measured by applying a voltage to (pixel), it was an extremely high value of 13: 1 as shown in the table.

Comparative Example 1 A liquid crystal display device having a structure without the white reflective layer in Example 1 was prepared. The structure was the same except that the white reflective layer was not provided, and the material and manufacturing method were the same as in Example 1. When the reflectance and the contrast ratio were measured in the same manner as in Example 1, the reflectance was 60%, which was a remarkably low value as compared with Example 1. Further, the contrast ratio was 9: 1, and it was found that the liquid crystal display element of the present invention of Example 1 obtained a sufficient value even if the white reflective layer was provided.

(Embodiment 2) FIGS. 11 and 12 show an active matrix liquid crystal display device having an MIM switching device having a color filter of this embodiment.

Two 0.7 mm thick glass substrates 11 and 12 are used.
A substrate with MIM element 18 as shown in FIGS. 11A and 11B was formed on one of the lower substrates 12 by using one sheet. FIG.
(A) shows the electrode shape of one pixel, 180 μm × 180
An electrode 14Y for yellow, an electrode 14M for magenta, and an electrode 14C for cyan are arranged in one pixel area of .mu.m.
FIG. 11B shows the shape of the effective display area 122. The number of pixels is 480 (× 3) × 320. This substrate 12 is used as a counter substrate of the observation side substrate. In this example, the lift-off method was not used for any of the patterns, and the resist was peeled off.

After that, as the observation side substrate 11, FIG.
The substrates with color filters shown in (c) and (d) were prepared. Yellow 27 as shown in FIGS. 11 (c) and 11 (d)
An ITO film having a film thickness of 2000 A was formed on the entire surface of the substrate using a substrate with a color filter 27 composed of three colored layers of Y 2, magenta 27M and cyan 27C. The film thickness of each color filter is 18000A. After a while
Positive resist material (OFPR-
5000, manufactured by Tokyo Ohka Co., Ltd. is applied to the entire surface, and 60
After calcination at 30 ° C. for 30 minutes, the ITO film 13 having the shape shown in FIG. 11C is exposed using a mask so that the pattern can be formed, and NMD3 solution (manufactured by Tokyo Ohka Co., Ltd.) is used.
After the development, the ITO film 13 of FIG. 11C was coated with the resist only, and then etching was performed with an aqueous hydrochloric acid / nitric acid solution (mixing ratio hydrochloric acid 10, nitric acid 1, water 10).

Then, a resist material (TiO2 dispersion, manufactured by Nippon Synthetic Rubber Co., Ltd.) in which TiO2 is dispersed over the entire effective display area of the substrate shown in FIG. 11 (d) is formed into a white layer having a film thickness of 20000A. To print 100
It was calcined at 30 ° C. for 30 minutes.

Next, the white layer is exposed to ultraviolet rays from the back surface of the substrate to remove the shadowed portion on the ITO film which will be the pixel electrode.
Cured.

Then, the ITO film 13 shown in FIG.
The resist coated only on a is ST10 solution ((Ltd.)
Peeled off by Tokyo Ohka. As a result, the resist material in which the TiO2 is dispersed is shown in FIG.
The pattern could be formed only in the area other than the ITO film 13 in (c). After that, the substrate is baked at 180 ° C. for 30 minutes for the purpose of completely curing the resist material in which the TiO 2 is dispersed, and when viewed from the back surface of the substrate, the present invention is formed in an area other than the colored portion of the color filter in the effective display area. The white reflective layer 20 having the characteristics of 1.

In the effective display area of this substrate, both the film thickness of the white reflective layer and the film thickness of the colored portion of the color filter (color filter film thickness + ITO film thickness) are 20000 A, and no surface step is formed. . Moreover, the boundary between the white reflective layer and the pixel electrode was a smooth edge.

As described above, in this embodiment, the white reflective layer is configured to eliminate the step between the colored portion of the color filter and the other regions.

The two substrates thus obtained were made into cells by using the same material and manufacturing method as in Example 1 as shown in FIG.
A quarter wave plate 31 and a reflection plate 3 are made of the same material and manufacturing method.
0 was attached to obtain a liquid crystal display device.

The reflectance and the contrast ratio of the liquid crystal display device of this example thus obtained were measured by the same method as in Example 1. The reflectance was 50% despite the absorption by the color filter. It was a very high value, and when the contrast ratio was measured, it was a very high value of 12: 1.

(Comparative Example 2) A liquid crystal display device having a structure without the white reflective layer in Example 2 was prepared. The structure was the same except that the white reflective layer was not provided, and the material and the manufacturing method were the same as in Example 2. When the reflectance and the contrast ratio were measured in the same manner as in Example 1, the reflectance was 25%, which was a significantly low value as compared with Example 2. Further, the contrast ratio was 6: 1, and it was found that the liquid crystal display element of the present invention of Example 2 obtained a sufficient value even if the white reflective layer was provided.

(Embodiment 3) FIG. 13 shows a liquid crystal display element of this embodiment.

Two glass substrates having a thickness of 0.7 mm were used, and one substrate 11 had a TF as shown in FIGS. 13 (a) and 13 (b).
A substrate with T18 was prepared. FIG. 13A shows the electrode shape of one pixel, and FIG. 13B shows the shape of the effective display area. One pixel is 180 μm × 180 μm, the number of pixels is 480
X320. This substrate 11 is used as an observation side substrate. First, TF is formed on the substrate 11 in the same manner as shown in FIG.
The T switching element 18 is formed, and thereafter, an ITO film is formed on the entire surface of the substrate with a film thickness of 2000 A, and a positive resist material: OFPR-5000 is used as a resist material.
(Manufactured by Tokyo Ohka Co., Ltd.) is applied over the entire surface, pre-baked at 60 ° C. for 30 minutes, and then exposed using a mask so that a pattern can be formed in the square shape shown in the drawing, and NMD3 solution (Tokyo, Inc.) is used. ITO developed and left as an electrode
After the resist is coated only on the film 13, a hydrochloric acid / nitric acid aqueous solution (mixing ratio hydrochloric acid 10 / nitric acid 1 / water 1
Etching was performed in 0). Thereafter, without removing the resist, a resist material (Ti 2) in which TiO 2 is dispersed over the entire effective display area 113 of the substrate 11 shown in FIG.
O2 dispersion: Nippon Synthetic Rubber Co., Ltd. film thickness 2000A
Was printed so as to form a white layer, and pre-baked at 100 ° C. for 30 minutes.

The ITO film 13 and the resist film thereon are used as a mask to perform back surface exposure with ultraviolet light from the back surface of the substrate so that the light is applied only to the areas of the white layer that should remain.

Then, a developing solution JCR for negative resist is used.
CD-150CR (trade name, manufactured by Nippon Synthetic Rubber Co., Ltd.) was used to peel off the white layer in the insufficiently cured region, and
The resist coated only on the ITO film 13 of (a) is treated with S
It was peeled off with a T10 solution (trade name, manufactured by Tokyo Ohka Co., Ltd.). As a result, the white layer made of the resist material in which TiO2 is dispersed is shown in FIG. 13 (a) in the effective display area 113.
The pattern could be formed only in the area other than the ITO film 13.

After that, the substrate was heated at 180 ° C. for 3 hours in order to completely cure the resist material in which the TiO 2 was dispersed.
After baking for 0 minutes, when viewed from the back surface of the substrate, the pixel electrode (ITO film 13 in FIG. 13A), the wiring portion (gate line, signal line) 22, and the space area other than the TFT element 18 are formed in the effective display area. The white reflective layer 20, which is a feature of the invention, could be formed.

Further, a substrate (not shown) having an ITO solid electrode was used as a counter substrate, and AL-1 was used as an alignment film.
051 (manufactured by Japan Synthetic Rubber Co., Ltd.) is printed and fired in the effective display area, and rubbed in a direction in which the facing substrates are 180 ° opposite to each other. Micropearl SP (manufactured by Sekisui Fine Chemical Co., Ltd.) having a diameter of 8 μm was sprayed at a spraying density of 100 / mm ^2, and a peripheral seal pattern with an opening of 5 mm width was formed around the effective display area of the counter substrate by the screen printing method. Formed. The seal material used here is XN-21 (manufactured by Mitsui Toatsu Chemicals, Inc.), which is a one-component epoxy resin.

Then, the two substrates are stacked so that their electrode surfaces face each other, and baked at 180 ° C. for 2 hours while pressurizing so that the substrate gap becomes equal to the grain size of the substrate gap material. An empty cell used for the liquid crystal display device of the invention was obtained. Thereafter, a nematic liquid crystal material (ZLI-2293;
Chiral material (S101 manufactured by Merck Japan Co., Ltd.)
1, 2% by weight of Merck Japan Co., Ltd., and 2.0% of black dye (LA103 / 4, manufactured by Mitsubishi Kasei Co., Ltd.)
% Addition is performed by a reduced pressure injection method, and the opening of the peripheral seal pattern is filled with an ultraviolet curable resin UV-1000.
A liquid crystal cell used in the liquid crystal display device of this example was obtained by sealing with (manufactured by Sony Chemical Co., Ltd.). The liquid crystal display device produced in this example is a PC-GH type LCD, and the helical pitch of the liquid crystal material used is set to 1.4 μm (controlled by the addition amount of the chiral material). Since the helical pitch is sufficiently shorter than the liquid crystal layer thickness (set to 8 μm), the spiral axis deviates from the normal direction, and the orientation of the dye molecules becomes practically random when no voltage is applied, resulting in a sufficient light absorption effect. (The effect of obtaining a dark state) is obtained.

As in Example 1, an M type diffuse reflector (manufactured by Nitto Denko Corporation) was attached to the outer surface of the counter substrate of the liquid crystal cell thus obtained to obtain a liquid crystal display element of this example.

The reflectance and contrast ratio of this liquid crystal display element were measured by the same method as in Example 1. As a result, a voltage was applied to the entire surface (all pixels) by using a TFT element so that the applied voltage to the liquid crystal layer was 14V. When applied, the reflectance is as high as 80%, and the applied voltage to the liquid crystal layer is 0V and 14V.
When the contrast ratio was measured by applying a voltage to the entire surface (all pixels) using the TFT element so that the voltage would be V, it was 15: 1.
It was an extremely high value. Here, the contrast ratio is higher than that of the first embodiment because the TFT element is used as the switching element, which enhances the effect together with the action of the present invention.

(Example 4) A liquid crystal display device of the present invention was prepared in the same manner as in Example 3 except that MgO was used as the white pigment for forming the white reflective layer. Created.

Similar to Example 3, the reflectance and the contrast ratio were measured at the driving voltage of 14 V by the same method as in Example 1. The reflectance was 78%, which was a very high value, and the contrast ratio was measured. , 15: 1, which was an extremely high value.

(Embodiment 5) FIGS. 14 and 15 show a liquid crystal display device for displaying characters such as numbers in this embodiment.

Two 0.7 mm thick glass substrates 11 and 1
2 is used, the segment electrode pattern 14 shown in FIG.
FIG. 8B shows the counter substrate 12 on which the ITO film is formed, and the observation-side substrate 11 on which the electrode pattern 13 of the ITO film is formed. Alignment films 16, 17 are formed on the electrode surfaces of these substrates as shown in FIG.
As a result, AL-1051 (manufactured by Nippon Synthetic Rubber Co., Ltd.) is printed in an effective display area and baked, and arrow directions r1 and r2 shown in FIGS. Rubbing in the opposite direction), then,
A space agent (Micropearl SP, manufactured by Sekisui Fine Chemical Co., Ltd.) having a particle size of 2.5 μm was sprayed on the observation side substrate 11 as a substrate spacing material at a spraying density of 100 / mm ² to form a counter substrate 1.
A peripheral seal pattern having a 5 mm wide opening around the effective display area 2 was formed by screen printing. The sealing material 28 used here is a one-component epoxy resin (XN-
21, manufactured by Mitsui Toatsu Chemicals, Inc.

Then, as shown in FIG.
The substrates 11 and 12 are superposed so that their electrode surfaces face each other, and baked at 180 ° C. for 2 hours while applying pressure so that the substrate gap becomes equal to the grain size of the substrate gap material, and the liquid crystal display of this embodiment is displayed. An empty cell used for the device was obtained. Next, a nematic liquid crystal material (ZLI-2293, manufactured by Merck Japan Co., Ltd.) exhibiting positive dielectric anisotropy as a liquid crystal material is injected into the empty cell as a liquid crystal composition 15 by a reduced pressure injection method to form the peripheral seal. The opening of the pattern is made of UV curable resin (UV
-1000, manufactured by Sony Chemical Co., Ltd., was sealed to obtain a liquid crystal cell used in the liquid crystal display device of this example. Then, LL is used as the polarizing plate 32 so that the structure shown in FIG. 15 is obtained.
C298-18SF (manufactured by Sanritsu Co., Ltd.) was attached to the outer surface of the observing side substrate 11 so that the absorption axis would be in a direction forming an angle of 45 ° with the rubbing direction, and the reflection plate 30 was an M type diffuse reflection plate ( ) Nitto Denko) counter substrate 1
2 pasted on the outer surface, and then, on the surface of the polarizing plate 32,
Resist material in which TiO2 is dispersed (TiO2 dispersion:
14C is printed so as to form a white layer having a film thickness of 2000 A, and the temperature is 70 ° C.
Then, the white reflective layer 20 was formed on the surface of the polarizing plate as seen in a cross section in a region which is a non-modulation part when seen in plan view.

In this embodiment, since the display pattern is not on a pixel-by-pixel basis, it is not possible to view the modulation section and the non-modulation section as one display unit. Therefore, the contrast ratio of the modulation section and the non-modulation section is discussed. Not worth. Therefore, in this example, only the reflectance was measured by the same method as in Example 1. When no voltage was applied, the reflectance was 50%, which was an extremely high value despite the use of the polarizing plate. Further, when a voltage of 5 V was applied to make the modulation portion in a dark state, the display was extremely good in visibility.

Example 6 FIG. 16 shows a liquid crystal display device of this example.

Two electrodes-attached substrate 1 used in Example 1
1 and 12 were used. The white reflective layer 20 formed in Example 1 is provided around the electrode 13 of the viewing side substrate 11. Next, alignment films (AL-1051, made by Japan Synthetic Rubber Co., Ltd.) 16 and 17 are printed on the surfaces of the electrodes 13 and 14 in the effective display area and fired so that the two substrates 11 and 12 face each other. Rubbing is performed so that the rubbing direction forms an angle of 90 ° when superposed, and then Micropearl SP (manufactured by Sekisui Fine Chemical Co., Ltd.) having a particle size of 4.5 μm is dispersed as a substrate gap material on the observation side substrate. It was sprayed at 100 / mm ^2, and a peripheral seal pattern having an opening with a width of 5 mm was formed around the effective display area of the counter substrate by a screen printing method. The seal material used here is a one-component epoxy resin X
N-21 (manufactured by Mitsui Toatsu Chemicals, Inc.).

Then, the two substrates are stacked so that their electrode surfaces face each other, and baked at 180 ° C. for 2 hours while pressurizing so that the substrate gap becomes equal to the particle size of the substrate gap material, and then the substrate is emptied. I got a cell. Then, a nematic liquid crystal material ZLI-2293 (manufactured by Merck Japan Co., Ltd.) showing a positive dielectric anisotropy as a liquid crystal material is injected into the empty cell as a liquid crystal composition layer 15 by a reduced pressure injection method to form the peripheral seal. The opening of the pattern is made of UV curable resin (UV-100
0, manufactured by Sony Chemical Co., Ltd., to obtain a liquid crystal cell used in the liquid crystal display device of this example. Then, a polarizing plate (LLC298-18SF, manufactured by Sanritsu Co., Ltd.) 3
2, 33 are attached to the outer surfaces of the two substrates so that the absorption axis is parallel to the rubbing direction, and an M type diffuse reflection plate (manufactured by Nitto Denko Corporation) is used as the reflection plate 30 on the outside of the polarizing plate of the opposite substrate. The liquid crystal display element of this example was obtained by pasting.

As in Example 1, the reflectance and the contrast ratio were measured by the same method as in Example 1 at a driving voltage of 4 V. The reflectance was 40% even though two polarizing plates were used. It was an extremely high value, and when the contrast ratio was measured, it was an extremely high value of 22: 1.

(Embodiment 7) As shown in FIG. 17, 0.7
Two glass substrates 11 and 12 having a thickness of mm were used, and a substrate with an MIM element as shown in FIGS. 7A and 7B was formed on one substrate 12. Unlike the substrate of FIG. 7A, this substrate 12 is used as the counter substrate of the observation side substrate. That is, the present example has the configuration of Example 1 shown in FIG. 7 and has the opposite surface of the cell as the observation side.

As the observing side substrate 11, as shown in FIG.
The ITO stripe pattern electrode substrate shown in (d) was prepared. In this example, the lift-off method was not used for any of the patterns, and the resist was peeled off. Thereafter, a resist material in which TiO2 is dispersed over the entire effective display area shown in FIG. 7 (d) on the surface of the ITO stripe pattern electrode substrate shown in FIGS. 7 (c) and 7 (d) (TiO2 dispersion liquid: manufactured by Nippon Gosei Co., Ltd.) (Made of rubber) so as to have a film thickness of 2000 A, and after provisional baking at 60 ° C. for 30 minutes, the pixel electrode 14 of the counter substrate 12 (ITO film 13 of FIG. 7A)
7C is exposed from the back side using a mask so that a pattern can be formed in the corresponding region of the observation substrate of FIG. 7C (that is, only the non-modulation part B can be formed), and the NMD3 solution (available from The product was developed by Tokyo Ohka Co., Ltd., and the white reflective layer 20 of the present invention was formed on the entire non-modulated portion of the viewing side substrate. Using the two substrates thus obtained, a liquid crystal cell was prepared by using the same material and manufacturing method as in Example 1, and the same material as in Example 1 (quarter The one-wave plate 31 and the reflection plate 30) were attached to the outer surface of the counter substrate 12 to obtain a liquid crystal display element according to this example.

In this embodiment, as compared with the first embodiment, the lift-off method is not used for the pattern formation of the white reflective layer 20, but the photolithography method is used. Although the number of manufacturing processes increases, the white reflective layer can be easily provided over the entire non-modulation portion, and further improvement in reflectance can be expected.

When the reflectance and the contrast ratio were measured by the same method as in Example 1 at a driving voltage of 4 V as in Example 1, the reflectance was 85%, which was a value extremely higher than that in Example 1, and the contrast When the ratio was measured, it was an extremely high value of 14: 1.

(Embodiment 8) In FIG. 19, (a) shows the counter substrate 12, (b) shows the observation side substrate 11, and (c) shows the cell cross section.

The counter substrate 12 has an IIM having a MIM element 18.
The TO pixel electrodes 14 are arranged in a matrix, and the wirings 22 extending in the row direction are provided between the pixel electrodes 14 arranged vertically, and the entire surface is covered with the alignment film 17.

The observing side substrate 11 has a plurality of stripe electrodes 13 made of ITO and extending in the column direction, and the white reflective layer 20 is formed in the gap separating the stripe electrodes 13. The white reflective layer 20 also serves as a substrate gap material, and has a thickness that allows the layer thickness of the liquid crystal composition 15 to be determined. Furthermore, an alignment film 16 is deposited on the entire surface of the substrate.

The white reflective layer 20 is formed by forming a resist material in which TiO2 is dispersed on the substrate 11 on which the stripe electrode 13 is formed (TiO2 dispersion liquid: manufactured by Nippon Synthetic Rubber Co., Ltd.).
Is printed to have a film thickness of 5 μm, and calcination is performed at 60 ° C. for 30 minutes, and then exposed using a mask so as to form a partially cut rod-shaped pattern shown in FIG.
Develop with D3 solution (Tokyo Ohka Co., Ltd.), 150 ° C 12
After baking for 0 minutes, the white reflective layer 20 of the present invention having the function of a substrate gap material was formed on a part of the non-modulated portion of the observation side substrate by backside exposure.

Using the two substrates thus obtained, a liquid crystal cell was prepared using the same material and manufacturing method as in Example 1, and as shown in FIG.
The same materials (quarter wave plate 31, reflection plate 30) as in Example 1 were attached to the outer surface of the counter substrate so that the structure as shown in (c) was obtained, and the liquid crystal display element of this example was obtained.

As in Example 1, the reflectance and the contrast ratio were measured at the driving voltage of 4 V by the same method as in Example 1. The reflectance was as high as 45%, and the contrast ratio was measured. It was a very high value of 10: 1.

Further, the thickness of the liquid crystal layer was measured by an interference film thickness meter, and it was found that the variation over the entire cell surface was ± 0.05 μm, which was a substantially uniform cell thickness.

[0111]

In the liquid crystal display device of the present invention, since the non-modulation portion is the white reflective layer in the dark state, the darkness and the blackness of the modulation portion can be seen conspicuously, and the non-modulation portion can be seen even in the bright state. Since it is a white reflective layer, the brightness is improved, the contrast ratio actually perceived is remarkably high, and a bright reflective liquid crystal display element can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view illustrating a configuration example of a liquid crystal display element of the present invention.

FIG. 2 is a plan view illustrating another configuration example of the liquid crystal display element of the present invention.

3A and 3B are plan views illustrating an example of a modulation section and a non-modulation section of the liquid crystal display element of the present invention.

FIG. 4 is a plan view illustrating another configuration example of the liquid crystal display element of the present invention.

FIG. 5 is a process diagram illustrating a method for manufacturing a liquid crystal display element of the present invention.

FIG. 6 is a cross-sectional view illustrating another configuration example of the liquid crystal display element of the present invention.

FIG. 7 is a view for explaining an electrode structure of a substrate of Example 1 of the present invention, (a) and (b) are observation side substrates, (c) and (d).
Is a plan view of the counter substrate

FIG. 8 is a sectional view illustrating an element according to Example 1 of the present invention.

9A and 9B are schematic diagrams for explaining the display principle of the liquid crystal display element of the embodiment of the present invention.

FIG. 10 is a diagram illustrating a reflectance measurement system of a liquid crystal display device.

11 (a), (b), (c), and (d) are plan views illustrating an electrode structure of a substrate and a planar structure of a color filter used in Example 2 of the present invention.

FIG. 12 is a sectional view illustrating an element of Example 2 of the present invention.

13 (a) and 13 (b) are plan views illustrating a substrate used in Example 3 of the present invention.

14 (a), (b) and (c) are the sixth embodiment of the present invention.
Plan view for explaining the electrodes of the substrate used for

FIG. 15 is a sectional view illustrating an element of Example 6 of the present invention.

FIG. 16 is a sectional view illustrating an element of Example 7 of the present invention.

FIG. 17 is a sectional view illustrating an element of Example 8 of the present invention.

FIG. 18 illustrates Example 90 of the present invention, in which (a)
Is a plan view of the electrode of the substrate, (b) is a cross-sectional view

FIG. 19 illustrates Example 100 of the present invention.
(A) and (b) are plan views of the electrodes on the substrate, and (c) is a cross-sectional view of the device.

FIG. 20 is a cross-sectional view illustrating a conventional two-polarization plate reflective TN-LCD.

FIG. 21 is a conventional single-polarizer-type reflective ECB-LCD.
Sectional view explaining

FIG. 22 is a sectional view illustrating a conventional reflective GH-PC-LCD.

FIG. 23 is a cross-sectional view illustrating a conventional reflective GH-HOMO-LCD.

FIG. 24 is a conventional two-layer reflective GH-HOMO-L.
Sectional view illustrating a CD

FIG. 25 is a reflection type G using a quarter-wave plate of the prior art.
Sectional drawing explaining H-HOMO-LCD

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Upper substrate 12 ... Lower substrate 13 ... Transparent electrode 14 ... Pixel electrode 15 ... Liquid crystal composition 18 ... Switching element 20 ... White reflective layer 22 ... Wiring layer 30 ... Reflector A ... Modulation part B ... Non-modulation part

 ─────────────────────────────────────────────────── ─── Continued front page (72) Inventor Hitoshi Hato 8 Shinsita-cho, Isogo-ku, Yokohama-shi, Kanagawa Stock company Toshiba Yokohama office (72) Inventor Hiro Morita 8 Shinsugita-cho, Isogo-ku, Yokohama, Kanagawa Company Toshiba Yokohama Office

Claims (4)

[Claims] 1. A method of manufacturing a reflective liquid crystal display device, comprising a liquid crystal composition sandwiched between two substrates with electrodes,
A step of depositing a transparent conductive layer on one transparent substrate surface, and a step of depositing a resist film on the transparent conductive layer and removing the resist film leaving a portion to be an electrode pattern of the transparent conductive layer. A step of etching the transparent conductive layer using the resist film as a mask to form an electrode pattern by the transparent conductive layer, and a white layer in which a white pigment is mixed in the resist on the substrate surface while leaving the resist film on the electrode pattern And a step of exposing the white layer using the transparent electrode and the resist film on the transparent electrode as a mask from the surface opposite to the surface on which the electrode pattern of the transparent one substrate is formed, Removing the resist film and the white layer on the transparent electrode, and forming a white reflective layer in all or a part of the area other than the electrode pattern. Method for producing a type liquid crystal display device. 2. A method of manufacturing a reflection type liquid crystal display device comprising a liquid crystal composition sandwiched between two substrates with electrodes,
A step of depositing a transparent conductive layer on one transparent substrate surface, and a step of depositing a resist film on the transparent conductive layer and removing the resist film leaving a portion to be an electrode pattern of the transparent conductive layer. A step of etching the transparent conductive layer using the resist film as a mask and removing the resist film used as the mask to form an electrode pattern of the transparent conductive layer; and a substrate surface with the resist film left on the electrode pattern. A step of depositing a white layer mixed with a white pigment on the resist, and selectively exposing the area of the white layer other than the transparent electrode from the surface opposite to the electrode pattern forming surface of the transparent one substrate. A reflective liquid crystal display comprising: a step of removing the white layer on the transparent electrode and forming a white reflective layer in all or a part of the area other than the electrode pattern. Method of manufacturing a child. 3. A method for producing a reflective liquid crystal display device, comprising a liquid crystal composition sandwiched between two substrates with electrodes having a color filter on one substrate, and a colored layer is coated on one transparent substrate surface. And a step of depositing a resist film on the colored layer and removing the resist film leaving a portion of the colored layer to be a color filter, and etching and coloring the colored layer using the resist film as a mask. A step of forming a color filter pattern by layers, a step of applying a white layer in which a white pigment is mixed in a resist to the surface of the substrate having the color filter pattern, and a step of exposing the white layer from the back surface of the transparent substrate And a step of removing the white layer on the color filter pattern and forming a white reflective layer in a region other than the colored layer. Display element manufacturing method. 4. The method of manufacturing a reflective liquid crystal display element according to claim 1, wherein the white reflective layer is formed in a region other than the pixel electrode and the wiring layer.