JP4028290B2 - Liquid crystal display device and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid crystal display device, and more particularly to a technique suitable for use in a transflective liquid crystal display device including a backlight and a reflective layer.
[0002]
[Prior art]
Currently, mobile phones and personal digital assistants are equipped with liquid crystal display devices in almost all products. Recently, many of these portable electronic devices have color display transflective liquid crystal display devices. .
The transflective liquid crystal display device includes a reflective layer for reflecting light incident from the outside on the inside or the outside of a pair of transparent substrates constituting the liquid crystal display device, and a backlight on the back side thereof. It can be used while switching between a reflection mode as a reflection type liquid crystal display device using sunlight or external illumination as a light source and a transmission mode as a transmission type liquid crystal display device using light from a backlight as a light source. It is possible.
[0003]
FIG. 11 is a diagram showing an example of a partial cross-sectional structure of a conventional transflective liquid crystal display device. In this figure, a conventional transflective liquid crystal display device 100 has a configuration in which a lower substrate 110 made of a transparent material such as glass and an upper substrate 120 are arranged to face each other, and a liquid crystal layer 130 is sealed therebetween. It is.
A transparent electrode 115 and an alignment film 116 are sequentially stacked on the surface of the lower substrate 110 on the liquid crystal layer 130 side. A transparent electrode 125 and an alignment film 126 are sequentially stacked on the surface of the upper substrate 120 on the liquid crystal layer 130 side.
A polarizing plate 118 is provided on the surface of the lower substrate 110 opposite to the liquid crystal layer 130 side (that is, the outer surface side of the substrate 110), and a reflection having a metal reflective layer 119a formed on the outer surface thereof. A layer 119 is attached with the reflective layer 119a facing the polarizing plate 118 side. A polarizing plate 128 is provided on the outer surface side of the upper substrate 120. On the back side of the liquid crystal display device 100, a backlight 105 for performing transmissive display in the liquid crystal display device 100 is provided.
The transflective liquid crystal display device 100 having the above configuration is used as a display unit of a mobile phone, for example, and operates in a reflection mode in which the backlight 105 is not turned on when sufficient external light is obtained. In an environment where it cannot be obtained, the backlight 105 is turned on to operate in the transmission mode.
[0004]
The reflection layer 119a is provided to reflect and scatter light incident on the liquid crystal layer 130 so that a bright display can be obtained. The reflective layer 119a is preferably made of a highly reflective metal material such as Al or Ag, and can be formed by a film formation method such as sputtering or vacuum evaporation.
If the film thickness of the metal reflection layer 119a is 80 to 500 mm, the light of the backlight can be guided to the liquid crystal layer 130 through the metal layer, and a bright display can be obtained. When the film thickness is thinner than 80 mm, the display in the reflection mode becomes dark because the reflectance of light by the metal reflection layer 119a is too small.
When the thickness of the metal reflection layer 119a is increased, the reflectance is increased and the display in the reflection mode is brightened. However, since the light in the transmission mode is insufficient and the display becomes dark, in order to secure the transmitted light, a fine hole for transmitting the light is provided in the metal reflection layer 119a to obtain a predetermined transmittance. Yes. In an LCD having these pores, a pore pattern is formed on the metal reflective layer by a photolithography method using a predetermined mask.
[0005]
[Problems to be solved by the invention]
However, when regular pores are provided in the metal reflective layer of each pixel using a mask, the transmitted light interferes with the thin film such as the transparent electrodes and color filters that make up the LCD, and a rainbow shape with directionality. There is a disadvantage that a beautiful display screen cannot be obtained due to the so-called moire pattern. When using a regular pattern, a slight twist may occur, and it is difficult to completely prevent the occurrence of moire.
The present invention has been made to solve the above-described drawbacks, and an object of the present invention is to provide a liquid crystal display device having a clear display screen free from moiré.
[0006]
[Means for Solving the Problems]
  In order to solve the above-described problem, the present invention includes a pair of substrates opposed to each other with a liquid crystal layer interposed therebetween, and a light source disposed on one outer side of the pair of substrates, and one of the pair of substrates. At least an organic film, a reflective layer, an overcoat film, an electrode layer, and an alignment film are formed on the surface on the liquid crystal layer side.The plurality of pores arranged in each pixel are provided on any one of the fixed points arranged in a matrix in the pixel, and are randomly selected from the fixed points arranged in the pixels. Selected and placedA liquid crystal display device was obtained.
  By disposing the plurality of pores in each pixel in a planar arrangement different from each other, a liquid crystal display device having a clear display screen in which interference of transmitted light by the thin film does not occur and no moiré occurs.
[0007]
  In the present invention, the plurality of pores arranged in each pixel are provided on fixed points arranged in advance in a matrix in the pixel.Therefore, when disposing at random with different planar arrangements, if they are arranged on fixed points arranged in a matrix in the pixel, random arrangement can be easily made by selecting random fixed points for providing pores. Convenient because it can be achieved. Then, the random arrangement of the pores is repeated over the entire display area, and the arrangement of the pores is randomly arranged over the entire pixel area. By adopting such means, it becomes possible to easily achieve random arrangement of pores in the entire display area.
[0008]
  In the present invention, the number of the fixed points arranged in each pixel is 3PiecesAbove, preferably 5 or more. The number of the plurality of pores arranged in each pixel is suitably 50% or more and 80% or less of the number of fixed points. This is because if a sufficient number of pores are provided, regularity can be eliminated so as not to cause light interference while securing a hole area for obtaining transmitted light.
[0009]
In the present invention, it is appropriate that the ratio of the sum of the areas of the plurality of pores to the area of one pixel is 10 to 30%, more preferably 15 to 30%.
This is to ensure high reflectivity in the reflection mode and to secure a sufficient amount of transmitted light in the transmission mode to balance the screen brightness in the reflection mode and the transmission mode.
[0010]
In the present invention, it is possible to use a reflective layer in which a large number of recesses whose inner surface forms part of a spherical surface are formed continuously on the metal reflective layer.
By using such a reflective layer, it is possible to effectively use the reflected light even when the external light is weak.
[0011]
  One of the methods for producing a liquid crystal display device according to the present invention is a transflective liquid crystal display device comprising at least a light source, a reflective layer, an electrode layer, and an alignment film on a pair of substrates facing each other with a liquid crystal layer interposed therebetween. A method of directly forming random array of pores in the reflective layerThe plurality of pores in each pixel are arranged in different planes, and the plurality of pores arranged in each pixel are arranged on a fixed point arranged in a matrix in the pixel. And fixedly selected from the fixed points arranged in each pixel and arranged.
  Directly form randomly arranged pores in the reflective layer using computer control of laser beamIt is possibleThe
  As another method, it is possible to create a photomask in which pores are randomly arranged, and to use the photomask to randomly form pores in the reflective layer by photolithography. In this case, a direct random sequencepluralForming poresIn this case, the planar arrangement of the plurality of pores in each pixel is different from each other, and the plurality of pores arranged in each pixel are on fixed points arranged in a matrix in the pixel. By forming a pore pattern using a photomask that is arranged at random and selected from the fixed points arranged in each pixel, as provided in any one of the above,A pore pattern can also be formed by randomly selecting from fixed points arranged in advance. If a photomask is used, it is possible to form randomly arranged pores in the reflective layer in the entire pixel region simply by transferring the mask pattern only by randomly arranging the pores for a specific block.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Next, the present invention will be specifically described with reference to the drawings. The present invention is not limited to the following embodiments. In the following drawings, the scale is not necessarily drawn accurately in order to make the configuration of the members easy to understand.
FIG. 1 is a perspective view of the entire liquid crystal display device 1 of the present invention as viewed from the upper surface side.
As shown in FIG. 1, a lower substrate 10 (first substrate) and an upper substrate 20 (second substrate) are arranged to face each other, and liquid crystal is interposed between substrates surrounded by a sealing material (not shown in FIG. 1). Layers (not shown in FIG. 1) are sandwiched. As the lower substrate 10 and the upper substrate 20, transparent substrates made of transparent glass, polycarbonate, polyethersulfone, acrylic resin, or the like are used. A phase difference plate 27 (for example, a typical λ / 4 plate, or a phase difference of about 100 to 200 nm deviating from λ / 4 depending on the phase difference of the panel or the setting of the angle of the polarization axis, etc.) The polarizing plate 28 is sequentially attached.
A large number of transparent electrodes 25 serving as signal electrodes are provided on the inner surface of the lower substrate 10 in stripes, and a large number of scans extending in a direction perpendicular to the transparent electrode 25 are formed on the inner surface of the upper substrate 20 facing the transparent electrodes 25. Transparent electrodes 15 serving as electrodes are provided in stripes. A portion where the transparent electrode 25 and the transparent electrode 15 intersect is an individual pixel 17, and a region where a large number of pixels 17 are arranged in a matrix is a display region 19.
An optical film in which a polarizing plate 18 and a phase substrate similar to the above are laminated is attached to the outside of the lower substrate 10, and a backlight 5 is further attached.
[0013]
FIG. 2 is a perspective view showing the structure of the reflective substrate 31 and the counter substrate 32 of the liquid crystal display device 1 shown in FIG.
As shown in FIG. 2, a reflective layer 12 made of a metal thin film such as aluminum is provided on the surface of the transparent lower substrate 10 made of glass or the like on the liquid crystal layer side, and the reflective layer 12 and the reflective layer 12 are directly above the reflective layer 12. Color filters 13B, 13G, and 13R are arranged so as to be in contact with each other. Each of the color filters 13B, 13G, 13R is formed in a matrix at a position facing the transparent electrode 25 of the other upper substrate 20. Each color filter is composed of a blue color filter ("B" in the figure), a green color filter ("G" in the figure), and a red color filter ("R" in the figure). Each color filter 13B, 13G, 13R is composed of three primary colors (B, G, R) of light. 1 and 2, the color filters 13B, 13G, and 13R are arranged with a certain interval.
[0014]
FIG. 3 is a diagram schematically showing a partial cross-sectional structure including an end portion of the liquid crystal display device of the present invention shown in FIG. In FIG. 3, a transflective liquid crystal display device 1 according to the present invention includes a lower substrate (first substrate) 10 made of transparent glass and the like, which is opposed to each other with a liquid crystal layer 30 interposed therebetween, and an upper substrate (second substrate). Of the two substrates 10 and 20 are bonded and integrated with a sealing material 40 provided in an annular shape on the periphery of the two substrates 10 and 20.
On the liquid crystal layer 30 side of the lower substrate 10, an organic film 11 for imparting an uneven shape to the reflective layer 12, a reflective layer 12 for reflecting light incident on the liquid crystal display device 1, and color display are sequentially provided. The color filters 13B, 13G, and 13R for performing, the organic film 11 and the reflective layer 12 are covered and protected, and the overcoat film 14 for flattening the unevenness due to the organic film 11 and the color filter, and the liquid crystal layer 30 are provided. A transparent electrode 15 serving as a signal electrode for driving and an alignment film 16 for controlling the alignment of liquid crystal molecules constituting the liquid crystal layer 30 are laminated. In addition, a transparent electrode 25 serving as a scanning electrode, an overcoat film 24, and an alignment film 26 are laminated in order on the liquid crystal layer 30 side of the upper substrate 20.
A polarizing plate 18 is provided on the side opposite to the liquid crystal layer 30 side of the lower substrate 10 (the outer surface side of the lower substrate 10), and the side opposite to the liquid crystal layer 30 side of the upper substrate 20 (the outer surface side of the upper substrate 20). ), A retardation plate 27 and a polarizing plate 28 are laminated in this order.
A backlight 5 is disposed outside the polarizing plate 18 of the lower substrate 10 as a light source for performing transmissive display in the liquid crystal display device 1.
[0015]
The organic film 11 is provided in order to give a concavo-convex shape to the reflective layer 12 made of a metal film formed thereon and to efficiently scatter reflected light. Thus, by providing the metal reflective layer 12 with a concavo-convex shape, light incident on the liquid crystal display device 1 can be efficiently reflected, so that bright display in the reflection mode can be realized.
[0016]
FIG. 4 is a diagram showing a pixel arrangement (usually called an oblique arrangement) in the display area of the liquid crystal display device shown in FIG. As shown in the figure, pixels 17 having color filters of the three primary colors (B, G, R) of light are arranged in a matrix in the display area 19. In addition to such diagonal arrangements, stripes, staggered lattices, delta arrangements, etc., which are mainly used for simple matrix types, are known, but the present invention is applicable to any of these arrangements. Is available. For example, in the figure, A × I is one pixel 17 indicating red (R). In the liquid crystal display device of the present invention, moire is prevented by randomly arranging the pores provided in the reflective layer. As an example of a method of randomizing the arrangement of the pores provided in the reflective layer, in FIG. 4, 16 pixels 17 surrounded by a thick line are made one block, and the arrangement of the pores is randomly arranged for these 16 pixels. . Then, this block is allocated to the entire display area 19, and the arrangement of the pores is randomly arranged over the entire pixel area by repeating the random arrangement of the pores. By adopting such means, random arrangement of the pores can be easily achieved.
[0017]
As a method of randomly arranging the pores in one block, a method of directly forming the pores directly in the metal film serving as the reflective layer can be used.
The pores of the reflection layer can be opened by irradiating the reflection layer made of a metal thin film with a laser beam or the like. The laser beam is controlled and scanned by random position information by a computer.
As another method, a photomask in which pores are randomly arranged in a plurality of pixels is created, and a plurality of mask patterns are transferred to a metal film serving as a reflective layer by using the photomask, and photolithography is performed. A method of forming pores can be used. In this case, when creating a photomask, a method of forming a pore pattern by randomly selecting a position for narrowing from a fixed point arranged in advance can be used.
[0018]
FIG. 5 is a diagram illustrating an example in which a randomly arranged pore pattern is provided in one pixel using fixed points arranged in advance. For example, 6 × f = 36 fixed points are assigned in a matrix in the A × I pixel 17 indicating red (R) in FIG. The pores are provided on this fixed point. The fixed points at which the pores are provided are randomly assigned using, for example, a random number table. The pores are randomly assigned to the 16 pixels shown in FIG.
FIG. 6 shows an example in which the pores 33 are randomly assigned to the 16 pixels in one block of the reflective layer using the random number table. In each pixel 17, 36 fixed points are arranged in a matrix, and among these, 18 fixed points have pores 33 opened. Moreover, the positions of the fixed points at which the pores 33 are opened for 16 pixels are all different, and the pores 33 are arranged at random.
[0019]
In order to determine the number of pores and the total opening area, it is important to consider the balance between the area of the reflective layer in the reflection mode and the area through which transmitted light passes in the transmission mode. In order to select the total opening area appropriately, the number of fixed points arranged in each pixel is preferably 3 or more. This is because if the number is too small, it is difficult to perform random arrangement. In addition, when the number of fixed points is too large, the opening area per piece becomes small and it becomes difficult to actually perform processing, so the number of fixed points is about 5 to 40, preferably about 7 to 30. Up to.
The number of the plurality of pores arranged in one pixel is preferably 50% or more and 80% or less of the number of the fixed points. Although it depends on the diameter of the pores, it is convenient for maintaining the balance between reflection and transmission of light and scattering randomly.
Under the above settings, the diameter and number of the pores are set so that the ratio of the sum of the areas of the plurality of pores to the area of one pixel is 10 to 30%.
[0020]
Through the above procedure, pores randomly arranged for one block of pixels are provided, and the pores of this block are transferred to the entire display area of the liquid crystal display device, thereby completing the random arrangement of the pores.
[0021]
In the present invention, in order to increase the light reflection efficiency in the reflection layer, a reflection layer in which a large number of recesses whose inner surface forms a part of a spherical surface can be used.
FIG. 7 is a perspective view showing an embodiment of the reflective layer of the present invention. The organic film 11 has a continuous surface such that a large number of recesses 12A whose inner surface forms a part of a spherical surface overlap each other on the left and right. The reflective layer 12 made of a metal thin film is laminated on the surface. The reflective layer 12 has pores 33 formed therein.
[0022]
The depth of the recess 12A is randomly formed in the range of 0.1 μm to 3 μm, the pitch of the adjacent recess 12A is randomly arranged in the range of 2 μm to 50 μm, and the inclination angle of the inner surface of the recess 12A is −30 degrees to It is desirable to set in the range of +30 degrees.
In particular, it is particularly important that the inclination angle distribution of the inner surface of the recess 12A is set in the range of −30 degrees to +30 degrees, and the pitch of the adjacent recess 12A is randomly arranged in all directions in the plane. This is because if there is regularity in the pitch of the adjacent recesses 12A, there is a problem that the interference color of light appears and the reflected light is colored. On the other hand, when the inclination angle distribution on the inner surface of the recess 12A exceeds the range of -30 degrees to 30 degrees, the diffusion angle of the reflected light is excessively widened, the reflection intensity is lowered, and a bright display cannot be obtained (the diffusion angle of the reflected light is This is because it becomes 36 degrees or more in the air, the reflection intensity peak inside the liquid crystal display device decreases, and the total reflection loss increases.
[0023]
If the depth of the recess 12A exceeds 3 μm, the top of the projection cannot be filled with the planarizing film (overcoat film 14) when the recess 12A is planarized in a later step, and desired flatness is obtained. This will cause display unevenness.
When the pitch of the adjacent recesses 12A is less than 2 μm, there is a restriction on the production of the transfer mold used to form the organic film 11, and the processing time is extremely long, and a shape capable of obtaining desired reflection characteristics is formed. Inability to generate interference light occurs. In practice, when a cemented carbide or diamond indenter having a diameter of 10 μm to 100 μm that can be used for manufacturing the transfer mold is used, it is desirable that the pitch of the adjacent recesses 12A be 2 μm to 50 μm.
[0024]
The most preferable liquid crystal display element of the present invention is a liquid crystal panel combined with a liquid crystal panel in which the reflection luminance-viewing angle characteristic of the liquid crystal panel has an asymmetric shape with respect to the light receiving angle. FIG. 8 is a diagram schematically showing the state of light reflection in the reflective liquid crystal panel. Light from the light source is incident on the normal line of the liquid crystal panel at an angle of −θ and reflected at an angle of + θ. Go. At this time, θ is the light receiving angle. FIG. 9 is a diagram showing the relationship between the light receiving angle θ and the reflected luminance. In the figure, a curve A is a case where the peak of the reflection luminance characteristic is in a certain angle range, and shows an asymmetric distribution with respect to the light receiving angle. A curve B is a case having a substantially flat reflection luminance characteristic in a certain angle range, and shows a distribution close to the object with respect to the incident angle. Curve C shows the reflection luminance characteristic of a conventional general liquid crystal panel. The curve C has a Gaussian distribution reflection luminance characteristic with respect to a certain light receiving angle. It is limited to a narrow range.
[0025]
Examples of such a reflection type liquid crystal panel exhibiting an asymmetric shape of reflection luminance characteristics are disclosed in Japanese Patent Application Nos. 2000-201530, 2001-197360 and 2000-201529 by the present applicant. In other words, when observing the liquid crystal panel surface by operating the information terminal device, it is often used at an angle relatively close to the normal line of the liquid crystal panel surface (for example, a light receiving angle of 0 degrees to 30 degrees), and the reflection characteristic is also this. Making it bright at such an angle is important in obtaining a bright reflective liquid crystal display device.
In this way, the reflective surface whose reflection characteristics are controlled is such that the inclination angle distribution of the concave (or convex) surface is in a direction in which the panel is expected in the randomly arranged minute concaves (or convexes) formed on the reflective surface. It can be realized with an asymmetry with respect to the vertical section along.
[0026]
FIG. 10 is a cross-sectional process diagram schematically illustrating a process of forming the organic film 11 of the reflective liquid crystal display device illustrated in FIG. 7, and reference symbols A to D indicate a process order.
First, as shown in FIG. 10A, a photosensitive resin liquid such as an acrylic resist is applied on the lower substrate 10 by spin coating or the like, and then pre-baked to form a photosensitive resin layer 11a.
Next, as shown in FIG. 10 (B), a transfer die 29 having a surface composed of an uneven surface 29a having an uneven shape and a flat surface 29b at the periphery thereof is pressed against the surface of the photosensitive resin layer 11a. Then, the shape of the uneven surface 29a of the transfer mold 29 is transferred to the surface of the photosensitive resin layer 11a.
The transfer die 29 has a surface shape shown in FIG. 7 by pressing a cemented carbide or diamond indenter on the surface of a flat base material made of brass, stainless steel, tool steel or the like. It is possible to produce a transfer mold base, and mold it with a material such as silicon resin using the transfer mold. Further, the transfer mold 29 has a concave and convex shape opposite to the surface shape of the many concave portions 12A shown in FIG.
[0027]
Next, as shown in FIG. 10C, a portion corresponding to the flat surface 29b on the periphery of the transfer mold 29 on the back surface 10a side of the lower substrate 10 on which the photosensitive resin layer 11a is formed is photo-processed. Cover with mask 21. Subsequently, light 22 such as ultraviolet rays (g, h, i rays) is irradiated from the back surface 10a side of the lower substrate to cure the photosensitive resin layer 11a.
Next, as shown in FIG. 10D, the photomask 21 is removed from the lower substrate 10, and the transfer mold 29 is removed from the photosensitive resin layer 11a. At this time, a portion of the photosensitive resin layer 11a corresponding to the flat portion 19b of the transfer mold 29 is not cured because it is masked by the photomask 21, and the transfer mold 29 is removed when the transfer mold 29 is removed. Will be removed. Thereafter, development and pure water rinsing are performed, and baking is performed by a heating means such as a heating furnace or a hot plate.
Through the above operation, the organic film 11 having an uneven shape on the surface is formed in a predetermined region on the lower substrate 10.
By forming the organic film 11 in the region excluding the peripheral portion of the substrate 10 in this way, it is possible to cover the end portion of the organic film 11 with the overcoat film 14 to be formed later. Thereby, it can prevent that the organic film 11 and external air touch directly, and can suppress deterioration of the organic film 11 by moisture.
[0028]
The reflective layer 12 made of a metal thin film is formed on the uneven surface of the organic film 11. The reflective layer 12 is preferably made of a highly reflective metal material such as Al or Ag, and can be formed by a film forming method such as sputtering or vacuum deposition.
In addition, since the metal material such as Al and Ag does not necessarily have good adhesion to the lower substrate 10 made of glass, a part of the reflective layer 12 is formed between the overcoat film 14 and the substrate 10. If it is, there is a risk of peeling of the metal film.
Therefore, when forming the metal film to be the reflective layer 12, the periphery of the lower substrate 10 on which the organic film 11 is not formed is covered with a mask material, and the mask material is removed after the film formation. It is preferable that the metal material film is not formed on the lower substrate 10.
The thickness of the reflective layer 12 is preferably in the range of 800 to 2500 mm. For example, a laser beam is irradiated to a predetermined position of the reflective layer 12 to provide the pores 33.
In the above embodiment, an example is shown in which a reflection film formed on a substrate of a panel is directly irradiated with a laser beam and processed, but the present invention also processes a pattern with random opening pattern positions with a laser beam. Then, after obtaining a photomask, the opening pattern may be formed by photolithography.
[0029]
[Action]
The present invention relates to a transflective color liquid crystal display device in which thin films such as a reflective layer, a transparent electrode, a color filter, and an alignment film are laminated, and light transmission pores provided in the reflective layer are randomly arranged in a plane. In order to prevent Moere caused by interference of transmitted light due to regularity.
[0030]
【The invention's effect】
  According to the present invention,The plurality of pores arranged in each pixel are provided on any one of the fixed points arranged in a matrix in the pixel, and are randomly selected from the fixed points arranged in the pixels. Are arranged,Since the pores provided in the reflective layer are randomly formed between each pixel, moiré occurs even for various pattern regularities such as transparent electrodes, color filters, reflective layers, etc. present in LCD panels. There are difficult advantages.
  In the present invention, the plurality of pores arranged in each pixel are provided on fixed points arranged in advance in a matrix in the pixel. Therefore, when the pixels are arranged randomly at different planar arrangements, If it arrange | positions on the fixed point arrange | positioned at matrix form, since random arrangement | positioning can be achieved easily by selecting the fixed point which provides a pore at random, it is convenient. Then, the random arrangement of the pores is repeated over the entire display area, and the arrangement of the pores is randomly arranged over the entire pixel area. By adopting such means, it becomes possible to easily achieve random arrangement of pores in the entire display area.
  In particular, by combining with a reflective layer whose reflection characteristics are controlled so as to be non-target, a bright reflective display can be obtained, and a liquid crystal display element with high display quality without any moire can be obtained.
  One of the manufacturing methods of the liquid crystal display device of the present invention is an arrangement in which the planar arrangement of the plurality of pores in each pixel is different from each other when the pores having a random arrangement are directly formed in the reflective layer. A plurality of pores arranged in each pixel are provided at any one of the fixed points arranged in a matrix in the pixel, and from among the fixed points arranged in the pixels Since the arrangement is selected at random, it is convenient because the random arrangement can be easily achieved by selecting a fixed point for providing the pores at random. Then, the random arrangement of the pores is repeated over the entire display area, and the arrangement of the pores is randomly arranged over the entire pixel area. By adopting such means, it becomes possible to easily achieve random arrangement of pores in the entire display area.
  Further, according to the present invention, it takes a little time to create a mask having a minimum repetitive pattern, but pores are randomly formed in the reflective layer by photolithography.In this case, the planar arrangement of the plurality of pores in each pixel is different from each other, and the plurality of pores arranged in each pixel are on fixed points arranged in a matrix in the pixel. A fine pattern provided in the reflective layer is formed by forming a pore pattern using a photomask arranged at random and selected from the fixed points arranged in each pixel. Holes can be formed randomly between each pixel.Once a pattern mask is created, random arrangement of pores can be easily achieved by photolithography. Furthermore, if the method of the present invention is routineized, it can be easily applied to LCD patterns having different repetition pitches.
[Brief description of the drawings]
FIG. 1 is a perspective view of an entire liquid crystal display device of the present invention as viewed from the upper surface side.
2 is a perspective view showing a structure of a reflective substrate and a counter substrate of the liquid crystal display device shown in FIG.
FIG. 3 is a diagram schematically showing a partial cross-sectional structure including an end portion of the liquid crystal display device shown in FIG.
4 is a diagram showing an arrangement of pixels in a display area of the liquid crystal display device shown in FIG.
FIG. 5 is a diagram illustrating an arrangement of fixed points provided on a reflective layer in one pixel.
FIG. 6 is a diagram showing an arrangement of transmission holes in one block of the reflective layer.
FIG. 7 is a perspective view showing an embodiment of a reflective layer of the present invention.
FIG. 8 is a diagram illustrating the definition of an incident angle.
FIG. 9 is a diagram illustrating a relationship between an incident angle and reflected luminance.
FIG. 10 is a cross-sectional process diagram illustrating an example of a method for forming a reflective layer according to the present invention.
FIG. 11 is a diagram showing a cross-sectional structure of a conventional liquid crystal display device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1,100 ... Liquid crystal display device, 5,105 ... Back light, 10,110 ... Lower substrate, 20, 120 ... Upper substrate, 30, 130, ..... Liquid crystal layer, 11 ... Organic film, 12, 119 ... Reflective layer, 12A ... Recess, 14, 24 ... Overcoat film, 15, 25 ... Transparent electrode 16, 26, 116, 126... Alignment film, 17... Pixel, 18, 28, 118, 128. ..Display area 31 .. reflective substrate 32. Counter substrate 33.

Claims (7)

A pair of substrates opposed to each other with a liquid crystal layer interposed therebetween, and a light source disposed on one outer side of the pair of substrates, wherein at least one of the pair of substrates has a surface on the liquid crystal layer side at least. An organic film, a reflective layer, an overcoat film, an electrode layer, and an alignment film are formed, and the reflective layer has a plurality of pores for transmitting light from the light source. The planar arrangement of the plurality of pores in each pixel is different from each other ,
The plurality of pores arranged in each pixel are provided at any one of fixed points arranged in a matrix in the pixel, and are randomly selected from the fixed points arranged in each pixel. A liquid crystal display device characterized in that the liquid crystal display device is arranged . The liquid crystal display device according to claim 1, wherein the number of the fixed points arranged in each pixel is three or more. 3. The liquid crystal display device according to claim 1, wherein the number of the plurality of pores arranged in each pixel is 50% to 80% of the number of the fixed points. The liquid crystal display device according to any one of claims 1 to 3 , wherein a ratio of a sum of areas of the plurality of pores to an area of one pixel is 10 to 30%. The liquid crystal display device according to any one of claims 1 to 4, wherein a plurality of depressions which form a part inner surface of the spherical to the reflective layer is formed continuously. A method of manufacturing a transflective liquid crystal display device comprising at least a light source, a reflective layer, an electrode layer, and an alignment film on a pair of substrates opposed to each other with a liquid crystal layer interposed therebetween, wherein the liquid crystal layer is directly arranged in random on the reflective layer matrix when forming a plurality of pores, planar arrangement of the plurality of pores in each pixel is different from an arrangement to each other, a plurality of pores wherein arranged in each pixel, the該画Motonai of A method of manufacturing a liquid crystal display device, wherein the liquid crystal display device is provided so as to be provided on any one of the fixed points arranged in a shape, and is randomly selected from the fixed points arranged in each of the pixels . A method of manufacturing a transflective liquid crystal display device comprising at least a light source, a reflective layer, an electrode layer, and an alignment film on a pair of substrates opposed to each other with a liquid crystal layer interposed therebetween, wherein pores are randomly arranged When creating a photomask and randomly forming pores in the reflective layer by photolithography using the photomask , the planar arrangement of the plurality of pores in each pixel is different from each other, A plurality of pores arranged in each pixel are provided on any one of fixed points arranged in a matrix in the pixel, and are randomly selected from the fixed points arranged in the pixels. A method of manufacturing a liquid crystal display device, wherein a pore pattern is formed using a photomask selected and arranged .

Images