JPH11202326A - Reflection type liquid crystal display element, and substrate for the reflection type liquid crystal display element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a pixel electrode and a reflection layer by a simple method in a reflection type liquid crystal display element capable of preventing the projection of the scene of a front surface and improving the contrast of images by providing the pixel electrode or the reflection layer with a light diffusion pattern. SOLUTION: An underlying layer 28 is formed by press-molding resin such as ultraviolet ray setting resin on the inner surface of a transparent substrate 22a for constituting the back surface side substrate of this reflection type liquid crystal display element, and simultaneously, an irregular pattern 31 fine compared to a pixel size is formed on the surface of the layer 28. An electrode martial is deposited in uniform thickness on the layer 28 by a vapor deposition method or a sputtering method and the pixel electrode 29 is formed for respective pixel areas. On the surface of the pixel electrode 29, by surfacing the pattern 31 of the layer 28, the light diffusion pattern 32 for scattering and reflecting external light is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a reflective liquid crystal display device and a substrate for the reflective liquid crystal display device. More specifically, the present invention relates to an improvement in reflected light characteristics in a reflective liquid crystal display device.

[0002]

2. Description of the Related Art A liquid crystal display device is a device in which liquid crystal molecules are sealed in a space called a liquid crystal cell formed between a pair of transparent substrates such as a glass substrate and a film substrate. By applying a voltage to the liquid crystal molecules in the liquid crystal layer to change the state of the liquid crystal molecules, an image is obtained by changing the optical refractive index of the liquid crystal cell for each pixel.

Further, since the liquid crystal display element itself has a feature of low power consumption, application to portable applications (for example, a display portion of a portable telephone) has been actively promoted. Further, as such a liquid crystal display element, a transmission type liquid crystal display element and a reflection type liquid crystal display element are generally known.

However, in a transmissive liquid crystal display device that uses a backlight as a light source and transmits light emitted from a backlight light source disposed on the back of the liquid crystal display device to the liquid crystal display device, thereby generating an image, Even if the power consumption is reduced by the liquid crystal display element, much power is consumed by the backlight as the light source. Therefore, there is a disadvantage that the power consumption as a whole increases and the characteristics of the liquid crystal display element cannot be utilized.

Therefore, in applications where power consumption is a problem, such as for portable use, a reflection type liquid crystal display element utilizing external light incident on the liquid crystal display element is often used. There are roughly two types of external light reflection methods in such a reflection type liquid crystal display element. As shown in FIG. 1, one type of reflective liquid crystal display element 1 (for example, TN type LCD)
Of the two transparent substrates 2a and 2b enclosing the liquid crystal layer 3, the color filter 4 and the transparent electrode 5 are formed on the inner surface of the front transparent substrate 2b, and the transparent electrode 6 is also formed on the inner surface of the rear transparent substrate 2a. Are formed, polarizers 7a and 7b are arranged on the outer surfaces of both transparent substrates 2a and 2b, and a reflector 8 is attached to the outside of the polarizer 7a on the back side. In the reflection type liquid crystal display element 1 of this system, in a bright pixel portion,
External light transmitted through the liquid crystal display element 1 from the front side to the back side is reflected by the reflection plate 8 on the back side, and the reflected light is transmitted from the back side to the front side of the liquid crystal display element 1 again.

Another type of reflection type liquid crystal display element 9
As shown in FIG. 2, a color filter 4 and a transparent electrode 5 are provided on the inner surface of the front transparent substrate 2b among the two transparent substrates 2a and 2b enclosing the liquid crystal layer 3 as shown in FIG. The pixel electrode 10 having a high surface reflectance is formed on the inner surface of the rear transparent substrate 2a with aluminum or the like, and the polarizing plate 7b is disposed on the outer surface of the front transparent substrate 2b. In the liquid crystal display element 9 of this type, in a bright pixel portion, external light incident from the front transparent substrate 2b is reflected by the pixel electrode 10, and the reflected light is returned to the front surface of the liquid crystal display element 9 again. I have.

In the former method, the manufacturing cost is reduced, but outside light incident on the liquid crystal display element 1 in the bright pixel portion is transmitted four times by reciprocating the front and back polarizing plates 7a and 7b, and the transparent substrate 2a and 2b must also pass four times in total. Here, the ideal transmittance of the polarizing plates 7a and 7b is 50%, and may actually be reduced to 43 to 45%. Even when the transparent substrates 2a and 2b are also glass substrates, the transmittances are high. Does not average more than 98% of visible light. For this reason, the reflection type liquid crystal display element 1 of the former type is used.
In this case, there is a problem in that the amount of reflected light that is reflected and returns to the front side of the incident external light is extremely small, and the contrast of an image is significantly reduced.

In the latter method, the number of manufacturing steps is increased and the cost is higher than in the former method. However, the number of times that external light transmits through the polarizing plate 7b and the number of times that the external light transmits through the transparent substrate 2b are also increased. Since it is performed twice, a loss of external light is small, the contrast of the image is high, and a bright and easy-to-view display is obtained.

However, in a reflection type liquid crystal display device, if the reflectance of external light is low, the contrast of an image is low, it is difficult to see the image, and practical use is difficult. The method of making it dominant is the mainstream.

[0010]

As described above, most of the conventional reflection type liquid crystal display elements reflect external light inside the liquid crystal cell. However, when the pixel electrode 10 serving as a reflector that reflects external light is flat, external light (that is, a front view) is reflected on the liquid crystal display element 9 as shown in FIG. In the direction deviating from the regular reflection direction, there is a problem that the contrast of the image is reduced and good visibility cannot be obtained. In particular, when the intensity of the incident light is high, the visibility is extremely deteriorated.

For this reason, the reflector (pixel electrode) used in the reflection type liquid crystal display element needs to have a certain degree of diffusion. Actually, as shown in FIG. 4, a light diffusion pattern 11 having a rounded and smooth uneven shape is formed on the surface of the pixel electrode 10 so as to have a light diffusion property, and as shown in FIG. The corner is widened.

As a conventional method of forming a pixel electrode having a light diffusion pattern, when depositing an electrode material such as aluminum on a transparent substrate as a base by a vacuum evaporation method or a sputtering method, a desired light diffusion There is a method of forming a pixel electrode having a light diffusion pattern by finely changing the deposition thickness of an electrode material film so as to form a pattern. Specifically, the electrode material that has passed through the opening of the mask is deposited on the transparent electrode, and the moving speed of the mask is accelerated or decelerated to finely control the moving speed, thereby forming an electrode material coating. Then, a light diffusion pattern is formed on the surface of the electrode material film, and then the electrode material film is divided for each pixel by etching to form a pixel electrode.

Alternatively, on a transparent substrate serving as a base,
After a thick electrode material such as aluminum is deposited, the surface of the electrode material film is etched using a resist to form a light diffusion pattern having fine irregularities on the pixel electrode.

Conventionally, an electrode material is deposited on a transparent substrate while the deposition thickness is finely changed as described above, or an electrode material is deposited thick on a transparent substrate, and then the electrode material film is formed by etching. Although irregular processing is performed, it takes too much time to form a pixel electrode having light diffusing property on each transparent substrate in any of the methods, and the manufacturing efficiency is poor. In addition, due to poor manufacturing efficiency,
The cost was high.

In the latter method, in which the surface of the electrode material film is made uneven by etching, a light diffusion pattern is formed on the surface of the pixel electrode by etching each transparent substrate. However, it is easily affected by whether the atmosphere is uniform or not, and is not suitable for forming a pixel electrode on a large-sized transparent substrate.

The present invention has been made in view of the above-mentioned drawbacks of the prior art, and has as its object to provide a pixel electrode having a light diffusion pattern or a reflective layer which can be provided by a simple manufacturing method. To provide a liquid crystal display device and a substrate for the display device.

[0017]

In the reflection type liquid crystal display element according to the present invention, a transparent substrate on the front side on which a transparent electrode is formed is opposed to a substrate on a rear side on which a pixel electrode is formed, and liquid crystal is sealed between the two substrates. In the reflection type liquid crystal display device described above, an uneven pattern finer than a pixel size is formed on the back side substrate, and a light reflective pixel electrode is formed on the uneven pattern in each pixel region.

In the liquid crystal display device according to the first aspect, since a concave and convex pattern finer than the pixel size is formed on the surface of the back side substrate, a pixel electrode having a uniform thickness is formed thereon. For example, a light diffusion pattern is formed on the surface of the pixel electrode. External light entering the reflective liquid crystal display element from the front side is reflected by the pixel electrode, but the reflected light is scattered because the light diffusion pattern is formed on the surface of the pixel electrode. Therefore, external light is no longer specularly reflected,
The reflection of the scenery on the front side is prevented, the contrast of the reflection type liquid crystal display element is improved, and the screen is easy to see.

In addition, since the pixel electrode may be formed on the underlayer with a uniform thickness, the electrode material deposited on the substrate may be etched to form a light diffusion pattern.
As compared with the conventional method of forming a light diffusion pattern by controlling the moving speed of the mask to change the deposition thickness of the electrode material, the fabrication of the pixel electrode becomes extremely simple.
The underlayer can be easily manufactured by embossing the resin.

According to a third aspect of the present invention, there is provided a substrate for a reflection type liquid crystal display element comprising a substrate for enclosing a liquid crystal and a concavo-convex pattern formed on the surface of the substrate and smaller than the pixel size of the display element. Since the light-reflective pixel electrode is formed on the concave / convex pattern, the substrate on the back side of the reflective liquid crystal display element according to the first aspect can be easily manufactured.

According to a second aspect of the present invention, there is provided a reflection type liquid crystal display device.
In a reflective liquid crystal display device in which a front transparent substrate on which a transparent electrode is formed and a rear substrate on which a pixel electrode is formed are filled with liquid crystal between the two substrates, the rear substrate has a smaller size than the pixel size. Forming an uneven pattern, forming a light reflection layer on the uneven pattern in each pixel region,
A transparent pixel electrode is formed corresponding to the light reflection layer.

In the reflection type liquid crystal display element according to the present invention, if a reflection layer having a uniform thickness is formed on the uneven pattern of the underlayer, a light diffusion pattern is formed on the surface of the reflection layer. . Therefore, the external light incident on the reflective liquid crystal display element is scattered and reflected, and the reflection of the scenery on the front side is prevented,
The contrast of the reflection type liquid crystal display element becomes good, and the screen becomes easy to see.

Moreover, in this case, since the reflective layer may be formed to a uniform thickness on the underlayer, the fabrication of the reflective layer and the pixel electrode becomes extremely simple.

According to a fourth aspect of the present invention, there is provided a substrate for a reflection type liquid crystal display element, comprising: a substrate for enclosing a liquid crystal; 3. The substrate on the back side of the reflective liquid crystal display device according to claim 2, wherein the substrate is constituted by a reflective layer formed on the surface of the concave and convex pattern, and a transparent pixel electrode is formed corresponding to the reflective layer. Can be easily manufactured.

[0025]

FIG. 6 is a partially broken sectional view showing the structure of a reflective liquid crystal display device 21 according to one embodiment of the present invention. In this reflective liquid crystal display element 21, a liquid crystal layer 23 is sealed between a pair of transparent substrates 22a and 22b, and a glass substrate or a film substrate is used as each of the transparent substrates 22a and 22b. Front side transparent substrate 22b
A color filter 24, a transparent electrode 25, and an alignment film 26 are formed on the inner surface of the substrate, a polarizing plate 27 is provided on the outer surface of the front transparent substrate 22b, and an underlayer 28 is formed on the inner surface of the rear transparent substrate 22a. A pixel electrode 29 and an alignment film 30 are formed.

FIG. 7 shows the structure (for one pixel) of the transparent substrate 22a disposed on the back side in detail. On a transparent substrate 22a made of a glass plate, a plastic film or the like, a base layer 28 made of a synthetic resin is formed for each pixel region, and a plurality of base layers 28 are formed on the surface of each base layer 28 as shown in FIG. The uneven pattern 31 in which the fine unevenness is uniformly and orderly arranged is formed. A pixel electrode 29 made of aluminum or the like having a uniform film thickness is formed on the uneven pattern 31 of the underlayer 28. The pixel electrode 29 also functions as a reflection plate, and a light diffusion pattern 32 having fine irregularities is formed on the surface of the pixel electrode 29 because of the irregularity pattern 31 of the underlayer 28. Also,
The base layer 28 and the pixel electrode 29 are provided corresponding to the display pixels, and the base layer 28 and the pixel electrode 29 in each adjacent pixel region are separated from each other.

On the transparent substrate 22a on the back side, polyimide, over the pixel electrode 29, is applied to the entire transparent substrate 22a.
An alignment film 30 made of an organic polymer such as polyamide, polyamide imide, polystyrene, epoxy acrylate or polyurethane is uniformly applied, and rubbed with a cloth or a brush. Similarly, the alignment film 26 is applied from above the transparent electrode 25 to the front transparent substrate 22b having the surface on which the color filter 24 and the transparent electrode 25 are formed, and rubbed. Next, a liquid crystal layer 23 is provided between the transparent substrates 22a and 22b.
Is assembled, and the reflection type liquid crystal display element 21 is assembled.

In such a reflective liquid crystal display element 21, in a dark pixel portion, external light enters from the front through the polarizing plate 27, is reflected by the pixel electrode 29, and returns to the polarizing plate 27. The light cannot be transmitted through the polarizing plate 27 because the polarization plane is rotated by 90 °, and becomes dark. On the other hand, in a bright pixel portion, external light that has entered from the front through the polarizing plate 27 is reflected on the surface of the pixel electrode 29 and is again reflected on the liquid crystal display element 2.
Get out of the front of 1. Moreover, the incident external light is reflected by the pixel electrode 29 and further scattered and reflected by the light diffusion pattern 32 on the surface.
Screen becomes brighter and the contrast of the image becomes better. In addition, the reflection of the scenery is also eliminated.

In addition, in the reflection type liquid crystal display element 21, a base layer 28 is formed on the surface of the transparent substrate 22a by embossing a resin or the like, and then a pixel electrode having a uniform thickness is formed on the base layer 28. Since it is only necessary to form the pixel electrode 29, the fabrication of the pixel electrode 29 can be facilitated and the cost can be reduced.

(Method of Forming Underlayer and Pixel Electrode) Next, the underlayer 28 is formed on the transparent substrate 22a by a so-called 2P (Photo-Polymerization) method using an ultraviolet curable resin which is cured by irradiation with ultraviolet rays. The method will be described. As shown in FIGS. 9 (a) and 9 (b), after supplying a transparent and transparent ultraviolet curable resin 33 onto the transparent substrate 22a, the stamper is moved from above the ultraviolet curable resin 33 toward the transparent substrate 22a. 34 is lowered [FIG. 9 (c)]. On the lower surface of the stamper 34, the uneven pattern 3 of the underlayer 28 is formed.
A plurality of inversion patterns 35 corresponding to 1 are formed at the same pitch as the pixel pitch. The stamper 34 is sufficiently pressed against the transparent substrate 22a, and the stamper 34 and the transparent substrate 22 are pressed.
a, an ultraviolet curable resin 33 is sandwiched between
After embossing the ultraviolet curable resin 33 with the inverted pattern 35 of No. 4, the ultraviolet curable resin 33 is irradiated with ultraviolet light (UV light) by an ultraviolet lamp or the like through the transparent substrate 22a as it is [FIG. ]. The ultraviolet-curable resin 33 irradiated with ultraviolet light undergoes a curing reaction when exposed to ultraviolet light, and is cured. Therefore, the reverse pattern 35 of the stamper 34 is transferred to the ultraviolet-curable resin 33 and is molded. An underlayer 28 is formed on the transparent substrate 22a, and an uneven pattern 31 is formed on the surface of the underlayer 28 (FIG. 9E). When the underlayer 28 is formed in this manner, an electrode material 36 such as aluminum is deposited on the uneven pattern 31 to a uniform thickness by a vacuum evaporation method, a sputtering method, or the like (FIG. 9F). Next, the deposited layer of the electrode material 36 is patterned by etching according to the pattern of the pixel electrode 29, and the electrode material is separated for each pixel region to form the pixel electrode 29 (FIG. 9G). At this time, the concavo-convex pattern 31 of the underlying layer 28 emerges on the surface of the pixel electrode 29 to become a light diffusion pattern 32.

As described above, the base layer 28 and the pixel electrode 2
9, the transparent substrate 22a is formed using the stamper 34.
The base layer 28 and the pixel electrode 29 can be easily formed on the substrate, and the base layer 28 is formed by curing the ultraviolet curable resin 33 by irradiating ultraviolet rays.
No need for curing time for resin curing, simple process,
In addition, the underlayer 28 can be formed in a short time, and the pixel electrode 29 only needs to be deposited to a uniform thickness, which is suitable for mass production.

The reason will be described in detail below. According to the 2P method, the underlayer 28 having the fine concavo-convex pattern 31 can be easily formed by transferring the reverse pattern 35 of the stamper 34 to the ultraviolet curable resin 33. By depositing an electrode material having a uniform thickness on the ground layer 28, the pixel electrode 29 having the light diffusion pattern 32 can be easily manufactured. In particular, by using a relatively low-viscosity ultraviolet-curable resin 33, pressing the mold with a stamper 34, and then irradiating and curing the resin, the reverse pattern 35 of the stamper 34 can be transferred with high accuracy. Large numbers of copies can be made. Further, in the 2P method, the ultraviolet irradiation light source is set to the transparent substrate 2.
The base layer 28 is formed only by performing the collective exposure on the entire area 2a, and only one processing step is required.

On the other hand, in the etching method, even if the same mask and the same setting conditions (for example, temperature, gas atmosphere, time, etc.) are used, depending on how light hits and the density distribution of the temperature and gas atmosphere concentration at that time, Variations increase. This is not suitable for a liquid crystal display element in which the height must be severely controlled on the order of 0.01 mm. Further, if a pixel electrode having a complicated shape is to be formed by controlling the moving speed by using a mask as in the related art, very complicated mask control is required, and the processing time becomes extremely long.

Also, since the base layer 28 can be formed only by embossing with the stamper 34 and then irradiating ultraviolet rays to cure the ultraviolet curable resin 33, the transparent layer is more transparent than a method using a thermosetting resin or an etching method. The processing time per substrate can be reduced. The processing time per substrate is inevitably time-consuming in principle, as long as a conventional etching method is used, for example.
It was a big neck.

Further, in the conventional method, the thickness of the pixel electrode itself becomes non-uniform, so that if the driving method of the liquid crystal display element is not devised, unevenness may occur in the pixel in some cases.
On the other hand, in the liquid crystal display element 21 of the present invention, such a problem can be solved because the thickness of the pixel electrode 29 can be made uniform.

Therefore, according to the present invention, the liquid crystal display element 2
(1) It is possible to easily and mass-produce a substrate with a pixel electrode, which greatly contributes to the demand for a wide viewing angle and the smoothness of the surface of the pixel electrode 29 sufficiently satisfies the requirement for the liquid crystal display element 21. Become. Further, according to the present invention, since there is little variation in manufacturing (variation within the same liquid crystal display element 21 and variation between the liquid crystal display elements 21), the above-described effects (for example, wide viewing angle) can be stably achieved. And excellent industrial productivity.

In the 2P method according to the present invention, an etching method is used for patterning a pixel electrode. However, this method is only used to obtain a planar pattern of a pixel electrode. There is no such problem. In particular, since the patterning of the pixel electrode can be collectively etched over the entire surface of the transparent substrate using a mask having a sufficiently large dimension, the number of steps is not significantly increased.

(Method of Manufacturing Stamper) The stamper 34
10 is shown in FIG. First, a glass plate 37 having a flat plate shape as shown in FIG. 10A is prepared, and the surface of the glass plate 37 is irradiated with laser light focused by an imaging lens 38 as shown in FIG. The glass plate 37 is evaporated and removed to a depth indicated by a two-dot chain line (39) by laser processing (laser lithography), and a desired concavo-convex pattern 39 (that is, the same shape as the concavo-convex pattern 31 of the underlayer 28) is formed on the surface of the glass plate 37. , Which is stored in a computer that controls the laser processing apparatus in advance). A master 40 made of the glass plate 37 is formed by forming a desired concavo-convex pattern 39 on the surface of the glass plate 37.
Nickel is deposited on the substrate, and a nickel master 41 which is an inverted type of the master 40 is manufactured by a nickel electroforming method [FIG.
0 (c)], the nickel master 41 is peeled off from the master 40 [FIG. 10 (d)]. When preparing the nickel master 41 by the nickel electroforming method, the master 40 is made conductive by, for example, a vapor deposition method or an electroless plating method, and the surface of the conductive master 40 is used as a cathode. The nickel master 41 is manufactured by electroplating in a nickel bath.

Since the nickel master 41 thus obtained also has the same pattern 42 as the inverted pattern 35 of the stamper 34, the nickel master 41 can be used as the stamper 34, but usually (industrial) this nickel master 41 is used. A stamper 34 is obtained by further copying 41 by nickel electroforming. When duplicating the nickel master 41, an oxide film is formed on the surface of the nickel master 41 using, for example, a potassium dichromate solution, and then a mother 43 (replica of the master) whose unevenness is reversed by nickel electroforming is again produced. [FIG. 10 (e)] Further, the mother 43 is formed by nickel electroforming.
Then, a stamper 34, which is a copy of the nickel master 41, is manufactured [FIG. 10 (f)]. Therefore,
When the stamper 34 is worn, it can be reproduced again from the mother 43.

In order to manufacture the stamper 34, FIG.
As shown in FIGS. 2A to 2F, the master 40 may be manufactured by laser processing the resist 44 applied to the surface of the glass plate 37. When the resist 44 is used, for example, a silane coupling agent is applied to the surface of the glass plate 37 as a bonding agent between the glass plate 37 and the resist 44, and after the laser processing, exposure, development and cleaning steps are performed. After that, the uneven pattern 3 by the resist 44
9 is formed on the surface of the glass plate 37 [FIG.
(B)]. Subsequent processing is performed in the same manner as in FIG. 10C and thereafter [FIGS. 12C to 12F].

(Second Embodiment) In the embodiment of FIG.
The projections forming each of the concavo-convex patterns 31 of the underlayer 28 appear to be separated from each other (actually, 0.5 to 0.5).
There is a thin resin layer of about 2 μm). In the structure shown in FIG. 13, the thickness of the underlayer 28 is increased (for example, several tens μm).
Degree), and the convex portions of the concave / convex pattern 31 are continuous.

The underlayers 28 provided in the respective pixel regions may be continuous as shown in FIG.
However, the pixel electrode 29 is divided for each pixel region.

When the underlayer 28 having such a shape is formed, as shown in FIGS. 15A to 15G, a sufficient amount of the ultraviolet curable resin 33 is supplied onto the transparent substrate 22a. By setting the lower limit position for lowering the stamper 34, a predetermined space may be left between the lowered stamper 34 and the transparent substrate 22a.

When the base layer 28 is transferred and formed on the transparent substrate 22a by the 2P method, the formed base layer 28
Is difficult to separate from the stamper 34, so that the transparent substrate 22a
There is a risk of peeling from. Therefore, in order to improve the releasability of the underlayer 28 from the stamper 34, the underlayer 2
A release agent (release agent) 45 may be mixed in advance with the ultraviolet-curable resin 33 for forming 8 (FIG. 1).
6). Alternatively, a chemical (primer, coupling agent) 46 having a function of improving the adhesion between the transparent substrate 22a and the base layer 28 may be applied in advance to the surface of the transparent substrate 22a (FIG. 17). Alternatively, the above methods may be used in combination.

(Third Embodiment) FIG. 18 is a partially cutaway sectional view showing the structure of a rear transparent substrate 22a used in a reflection type liquid crystal display device according to still another embodiment of the present invention. In this embodiment, after the base layer 28 is formed on the transparent substrate 22a, aluminum or an aluminum alloy or the like is deposited in a uniform thickness on the concave / convex pattern 31 of the base layer 28 by an evaporation method, a sputtering method, or the like. The reflection layer 47 is formed for each pixel region. Therefore, the reflection layer 4
On the surface of 7, a light diffusion pattern 48 in which the concavo-convex pattern 31 protrudes and has a concavo-convex shape is formed. Further, the reflection layer 4
A transparent pixel electrode (transparent electrode) 49 made of ITO or the like is formed on the substrate 7 so as to have a uniform thickness. In this case, as shown in FIG. 19, the underlying layer 28 of each pixel region may be continuous.

In the case where the reflection layer 47 is used, FIG.
As shown in FIG. 0, a base layer 28 is formed on the outer surface of the transparent substrate 22a, and a reflection layer 47 made of aluminum or an aluminum alloy is formed on the uneven pattern 31 of the base layer 28 in each pixel region. A transparent pixel electrode 49 made of ITO or the like may be formed flat on the inner surface of the transparent substrate 22a so as to face the same.

In each of the above embodiments, the case where the underlayer is formed on the surface of the transparent substrate by forming the underlayer on the surface of the transparent substrate by the 2P method or the like has been described. A base may be integrally formed by pressing a heating mold against the surface, or a concave portion may be formed on the surface of a transparent substrate made of a glass plate by etching or the like. However, the former method has poor shape stability and is easily deformed, and it is difficult to perform fine processing. Further, in the latter method, the accuracy (shape, height, flatness, and the like) of the etching of the glass plate is further poor, and cannot be said to be a good method. Therefore, it can be said that the 2P method of forming a base layer on the surface of a transparent substrate using an ultraviolet curable resin is the best.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a conventional reflective liquid crystal display device.

FIG. 2 is a schematic sectional view showing another conventional reflection type liquid crystal display device.

FIG. 3 is a schematic diagram showing reflection of incident light by a flat reflector.

FIG. 4 is a cross-sectional view showing a transparent substrate on which a pixel electrode having a light diffusion pattern is formed.

FIG. 5 is a cross-sectional view showing a state in which external light is scattered and reflected in a liquid crystal display device using a pixel electrode having a light diffusion pattern.

FIG. 6 is a partially broken sectional view showing a reflective liquid crystal display device according to an embodiment of the present invention.

FIG. 7 is an enlarged cross-sectional view showing a base layer and a pixel electrode formed on the transparent substrate of the above.

FIG. 8 is a plan view showing a concavo-convex pattern of the underlayer according to the third embodiment.

FIGS. 9A to 9G are schematic diagrams illustrating a method of forming a base layer and a pixel electrode on a transparent substrate.

FIGS. 10A to 10F are diagrams illustrating a method of manufacturing a stamper for forming an underlayer.

FIG. 11 is a diagram showing a state in which a glass plate is laser-processed.

FIGS. 12A to 12F are diagrams illustrating another method for manufacturing a stamper for forming an underlayer.

FIG. 13 is a cross-sectional view showing an underlayer and a pixel electrode formed on a transparent substrate according to another embodiment of the present invention.

FIG. 14 is a cross-sectional view showing a base layer and a pixel electrode formed on a transparent substrate in still another embodiment of the present invention.

FIGS. 15A to 15G are schematic views illustrating a method of forming an underlayer and a pixel electrode on a transparent substrate.

FIG. 16 is a diagram illustrating a method for improving the releasability of a stamper and an underlayer.

FIG. 17 is a diagram illustrating another method for improving the releasability of the stamper and the underlayer.

FIG. 18 is a cross-sectional view showing a base layer, a reflective layer, and a transparent pixel electrode formed on a transparent substrate according to still another embodiment of the present invention.

FIG. 19 is a cross-sectional view showing a base layer, a reflective layer, and a transparent pixel electrode formed on a transparent substrate according to still another embodiment of the present invention.

FIG. 20 is a cross-sectional view showing a base layer, a reflective layer, and a transparent pixel electrode formed on a transparent substrate according to still another embodiment of the present invention.

[Explanation of symbols]

 22a, 22b Transparent substrate 28 Underlayer 29 Pixel electrode 31 Concavo-convex pattern 32 Light diffusion pattern of pixel electrode 33 Ultraviolet curing resin 34 Stamper 47 Reflective layer 48 Light diffusion pattern of reflective layer 49 Pixel electrode (transparent electrode)

Claims (4)

[Claims] 1. A reflective liquid crystal display device in which a front transparent substrate on which a transparent electrode is formed and a rear substrate on which a pixel electrode is formed are opposed to each other, and a liquid crystal is sealed between the two substrates. A reflection type liquid crystal display device, wherein a concave / convex pattern finer than a pixel size is formed, and a pixel electrode having light reflectivity is formed on the concave / convex pattern in each pixel region. 2. A reflective liquid crystal display device in which a front transparent substrate on which a transparent electrode is formed and a rear substrate on which a pixel electrode is formed are opposed to each other, and a liquid crystal is sealed between the two substrates. A reflection pattern characterized by forming a concavo-convex pattern finer than the pixel size, forming a light reflection layer on the concavo-convex pattern in each pixel region, and forming a transparent pixel electrode corresponding to the light reflection layer. Liquid crystal display device. 3. A substrate for a reflective liquid crystal display device, comprising: a substrate for enclosing liquid crystal; and a concavo-convex pattern formed on the surface of the substrate and smaller than the pixel size of the display device. . 4. A substrate for enclosing liquid crystal, a concavo-convex pattern formed on the surface of the substrate, which is finer than a pixel size of a display element, and a reflective layer formed on the surface of the concavo-convex pattern. A substrate for a reflection type liquid crystal display device, characterized in that: