JP2005241894A - Liquid crystal display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an internal reflection type liquid crystal display device capable of various displays according to applications.
A plurality of base layers 6a are arranged in an island shape in a predetermined arrangement on the surface of a rear glass substrate 2 facing the front glass substrate 1, and these base layers 6a are interposed between them. A surface reflection film 6b is deposited so as to cover the exposed surface of the rear glass substrate 2. The color filter layer 7 composed of the red, green, and blue color elements 7r, 7g, and 7b is formed on the surface of the surface reflection film 6b having an uneven surface according to the arrangement of the base layer 6a so that the surface is flat. Are stacked. As a result, even if the light rays a and b are incident and reflected on the color elements of the same color, the thicknesses of the incident color elements are different, so that the reflected light has different color purity and brightness.
[Selection] Figure 1

Description

  The present invention relates to a reflection type liquid crystal display device in which a light reflection film is provided on a liquid crystal sealing side surface (hereinafter referred to as an inner surface) of a substrate.

  The reflective liquid crystal display device includes an internal reflective type in which a light reflecting film is disposed on the inner surface of the rear substrate opposite to the front substrate on the display side, and an outer reflective type in which the light reflective film is disposed on the outer surface of the rear substrate. There are things.

  The external reflection type liquid crystal display device is easy to manufacture, but light is transmitted through two substrates that are much thicker than other members, and therefore, image blur due to parallax due to the thickness of the substrate is generated. It has a drawback that the display quality is deteriorated.

On the other hand, in the internal reflection type liquid crystal display device, as shown in Patent Document 1, since light only passes through one front substrate, image blur due to parallax is remarkably eliminated. However, reflective liquid crystal display devices that display using external light as a light source tend to be monotonous and plain compared to transmissive liquid crystal display devices that can use chromatic light as a light source. Has the disadvantage of being limited
JP 2002-214600 A

  An object of the present invention is to provide an internal reflection type liquid crystal display device that enables various displays depending on the application.

  In order to solve the above problems, a liquid crystal display device according to the present invention is a liquid crystal in which liquid crystal is sealed between a front substrate disposed on a display viewing side and a rear substrate on the side opposite to the display viewing side. In the display device, a light reflection film is provided on a surface of the rear substrate facing the front substrate, and the light reflection film has at least two kinds of light reflection different from each other in visual characteristics given to an observer of reflected light. It is characterized by having an area.

  According to the liquid crystal display device of the present invention, since the light reflecting film having at least two types of light reflecting areas having different visual characteristics given to the observer of reflected light is provided on the inner surface of the rear substrate, image blur due to parallax is caused. In addition to being remarkably improved, the plain and monotonous reflection display becomes a variety and varied display. As a result, the application as a reflective liquid crystal display device can be widely expanded to amusement equipment and the like.

  In the liquid crystal display device of the present invention, it is preferable that a color filter layer composed of a plurality of color elements and having a substantially flat surface is laminated on the surface of the light reflecting film. A display is obtained. In this case, it is preferable that the surface of the light reflecting film is a concavo-convex surface, whereby the concave and convex portions of the light reflecting film have different distances through which the light to be reflected passes through the color filter. Even if the light passes through the element, the hue of the reflected light is slightly different, and the color display becomes more diverse.

  In the liquid crystal display device of the present invention, it is preferable that the light reflecting film has at least two kinds of light reflecting areas having different light reflectances arranged side by side. A reflective display with a background pattern is obtained.

  Further, in the liquid crystal display device of the present invention, it is preferable that the light reflecting film is formed by arranging at least two kinds of light reflecting areas having different reflection angles with respect to the incident angle of light, and thereby the luminance depending on the viewing angle. Reflective display in which the background pattern consisting of the height of the pattern changes is obtained.

  Furthermore, in the liquid crystal display device of the present invention, it is preferable that the light reflecting film is formed by arranging at least two kinds of light reflecting areas having different colors of reflected light from each other. A unique reflective display with a background pattern consisting of the above differences can be obtained.

  Furthermore, in the liquid crystal display device of the present invention, the second reflective film may be laminated in a scattered state on the first reflective film having a constant film thickness. In this case, the first reflective film and the first reflective film As the reflective film 2, it is preferable to install reflective films having different reflectances, reflection angles, or colors, so that reflections having various background patterns with different brightness, viewing angle characteristics, and colors are the same color. A display is obtained.

  In addition, in the liquid crystal display device of the present invention, it is preferable that the light reflection film is a light transmission film disposed in a scattered state on a reflection film having a constant film thickness. A reflective display having a background pattern formed by the difference in both characteristics is obtained.

Hereinafter, preferred embodiments of the present invention will be described.
FIG. 1 is a schematic cross-sectional view showing a simple matrix reflective liquid crystal display device as a first embodiment of the present invention.

  In FIG. 1, a pair of glass substrates 1 and 2 are joined together with a predetermined gap through a sealing material (not shown) arranged in a frame shape. A liquid crystal Lc is sealed between the pair of glass substrates 1 and 2.

  A plurality of display electrodes 3 are arranged in parallel to each other in the direction perpendicular to the paper surface on the inner surface of a glass substrate 1 (hereinafter referred to as a front glass substrate) 1 positioned on the front side of the pair of glass substrates 1 and 2 for observing the display. It is installed. A black matrix 4 made of a light shielding material such as resin black is disposed between the display electrodes 3. An alignment film 5 is uniformly deposited over the display electrodes 3 and the black matrix 4. This alignment film 5 is subjected to an alignment process in a predetermined direction in order to regulate the alignment of liquid crystal molecules.

  On the other hand, a light reflecting film 6 is provided on the inner surface of the rear glass substrate 2 disposed to face the front glass substrate 1. The light reflecting film 6 includes a plurality of base layers 6a that are directly disposed on the inner surface of the rear glass substrate 2 in a predetermined arrangement, and a single-film surface reflective film 6b that is laminated so as to cover these base layers 6a. Consists of. Therefore. The surface of the light reflecting film 6 that reflects light, that is, the light reflecting surface is the surface of the surface reflecting film 6b, and this surface forms an uneven surface following the arrangement of the underlayer 6a.

  A color filter layer 7 having a substantially flat surface is laminated on the surface of the light reflecting film 6. The color filter layer 7 includes red, green, and blue color elements 7r, 7g, and 7b arranged in a predetermined arrangement. Each of the color elements 7r, 7g, and 7b is formed by applying each color element material uniformly on the surface of the light reflecting film 6 by a spin coat method or the like to form a color element film having a flat surface, and then by photolithography. Is patterned to a predetermined size.

  In the color filter layer 7 formed as described above, there are a thick portion and a thin portion even if the color elements have the same color. The color purity and brightness of each light incident on the different color layer portions of the same color and reflected by the surface of the surface reflecting film 6b are different from each other. That is, for example. Even if both rays are incident on the red element 7r, the rays b are incident on and reflected by the thin portion formed on the convex surface of the surface reflecting film 6b. Compared with the light ray b incident on and reflected by the thick portion formed on the surface, the color purity is inferior, but it is bright red light with higher brightness.

  A transparent protective film 8 is laminated on the color filter layer 7, and a plurality of scanning electrodes 9 are disposed on the color filter layer 7 in parallel to the direction orthogonal to the display electrodes 3 (paper surface direction). Then, the alignment film 10 is uniformly applied over the scan electrodes 9. The alignment film 10 is subjected to an alignment process in a predetermined direction.

  As described above, in the liquid crystal display device of this embodiment, the surface reflection film 6b is coated on the interspersed base layer 6a to form the light reflection film 6 with the uneven surface. By laminating a color filter layer having a flat surface on the surface, a portion having a different layer thickness exists in the color element of the same color, so that the color element of the same color of the color filter layer 7 is transmitted and reflected. Even if the light is different, color purity and luminance can be made different. As a result, a color display having various hues can be obtained. In addition, the light reflection film provided with the uneven reflection surface can also be obtained by individually forming a plurality of types of reflection films having different layer thicknesses by photolithography or the like in a predetermined arrangement.

  Next, a second embodiment of the present invention will be described based on the schematic cross-sectional view of FIG. FIG. 2 shows only the laminated structure on the rear glass substrate 2 in the simple matrix reflective liquid crystal display device, and the structure of other parts not shown is the same as that of the first embodiment. The same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. The same applies to the following embodiments.

  In FIG. 2, a light reflecting film 11 in which first reflecting films 11 a and second reflecting films 11 b having the same film thickness and different light reflectivities are alternately arranged in parallel on the inner surface of the rear glass substrate 2. Is installed. Therefore, the surface which becomes the light reflecting surface of the light reflecting film 11 is a flat surface.

  A color filter layer 12 having a constant thickness is laminated on the light reflection film 11 described above. The color filter layer 12 includes red, green, and blue color elements 12r, 12g, and 12b having the same layer thickness arranged in a predetermined arrangement.

  On the color filter layer 12, the transparent protective film 8, the scanning electrode 9, and the alignment film 10 are sequentially laminated as in the first embodiment.

  In the second embodiment configured as described above, since the thickness of the color filter layer 12 is constant throughout, the spectral transmission effect of the color element received by the light incident on the color element of the same color is the color. Even if the positions of the elements are different, the same is true, but the brightness of the reflected light differs if the light reflectance of the reflected light reflecting surface is different. For example, both the light ray A and the light ray B are incident on the red element 12g having the same layer thickness, but are reflected by the respective surfaces of the first reflection film 11a and the second light reflection film 11b having different light reflectivities. The light beams a and b emitted to the liquid crystal layer Lc side have the same brightness even though they exhibit the same red color.

  As described above, according to the liquid crystal display device of the present embodiment, reflected light having different luminance can be obtained even with the same color, and thus display light with various hues can be obtained, and the first reflective film 11a and the second reflective film 11b can be obtained. Various color displays with a background pattern according to the arrangement are possible.

  As a modification of the second embodiment, the first reflection film 11a and the second reflection film 11b may be light reflection films having different reflection angles with respect to the incident angle of light. Specifically, for example, the surface of the first reflective film 11a may be finished as a mirror surface, and the second reflective film 11b may be a surface as formed. In other words, the light reflecting film 11 is uniformly formed of the same material, and the treatment applied to the surface of the light reflecting film 11 is partially different to partition the first reflecting film 11a and the second reflecting film 11b. In addition to this, it is also possible to change the material of the reflective film, change the film formation method to the sputtering method and ion plating method using the same material, or change the film formation conditions such as temperature and degree of vacuum. The first reflection film 11a and the second reflection film 11b having different reflection angles with respect to the incident angle of light can be formed. According to the modified example configured as described above, a color display in which a background pattern composed of high and low luminance changes depending on the viewing angle can be obtained.

  As another modification, the first reflective film 11a and the second reflective film 11b may be formed of metal films having different colors. Metals and alloys such as gold, silver, copper, and brass each have a different color of reflected light, that is, gloss. Therefore, by configuring the light reflecting film 11 by combining these metals and alloys having different glossy colors, a color display having a background pattern made of reflected metal lights having different colors can be obtained. In this case, the first reflective film 11a and the second reflective film 11b having different colors of reflected light can be formed not only by a metal film but also by combining light reflective films of other various materials. .

Next, a third embodiment of the present invention will be described with reference to FIG.
On the inner surface of the rear glass substrate 2, a first reflective film 13 is uniformly applied with a constant film thickness. On the first reflective film 13, an acid-resistant transparent film 14 is uniformly laminated with a constant film thickness. On the acid-resistant transparent film 14, a plurality of second reflective films 15 are arranged in a predetermined arrangement. Then, the color filter layer 7 having the same configuration as that of the first embodiment is deposited so as to cover the second reflective film 15 and the acid-resistant transparent film 14 therebetween. That is, the color filter layer 7 is formed so that the surface is a flat surface, and therefore the layer thickness is different between the area where the second reflective film 15 is installed and the area where the second reflective film 15 is not installed.

  On the color filter layer 7, as in the first embodiment, a transparent protective film 8, a scanning electrode 9, and an alignment film 10 are sequentially laminated. The acid-resistant transparent film 14 is a film that protects the first reflective film 13 from being eroded by the etchant when the second reflective film 15 is formed by photolithography.

  Here, the first reflective film 13 and the second reflective film 15 are light reflective films having different light reflectivities. Therefore, the area where the second reflective film 15 is provided and the area where the second reflective film 15 is not provided are different in the thickness of the color filter layer 7 laminated thereon and in the light reflectance of the light reflecting surface. In the present embodiment, the light reflectance of the second reflective film 15 is set higher than the light reflectance of the first reflective film 13.

  In the liquid crystal display device of the present embodiment configured as described above, even in an area where color elements of the same color are provided, both the thickness of the color elements and the light reflectance of the light reflecting surface are different. Exists. Therefore, the difference in color purity and luminance of the reflected light transmitted through the portions where both the layer thickness and the light reflectance are different is more prominent in the present embodiment than in the first embodiment. For example, even if the light beam is incident on the same blue element 7b, the light beam A is incident on the thick portion formed on the surface of the first reflective film 13 and the first reflective film having a low light reflectance. 13 is reflected on the surface of the second reflective film 14, so that the color purity is higher than that of the light ray incident on the surface of the second reflective film 14 having a high light reflectivity. Is dark blue light with high brightness but much lower brightness. As described above, according to the liquid crystal display device of the third embodiment, the difference in luminance between the light with high color purity and the light with low color among the display light of the same color is increased, and as a result, the change is more varied. Color display with various hues can be obtained. In this case, if the light reflectance of the first reflective film 13 is set higher than the light reflectance of the second reflective film 15, the difference in luminance is suppressed.

  As a modification of the third embodiment, the first reflection film 13 and the second reflection film 15 may be light reflection films having different reflection angles with respect to the incident angle of light. In this case, the reflective film may be made of different materials, the film formation method may be changed to the sputtering method and ion plating method using the same material, or the film formation conditions such as temperature and degree of vacuum may be changed. The first reflection film 11a and the second reflection film 11b having different reflection angles with respect to the incident angle can be formed. According to the modified example configured as described above, a color display in which the background pattern due to the difference between the luminance and the color purity changes depending on the viewing angle can be obtained.

  As another modification of the third embodiment, the first reflective film 13 and the second reflective film 15 may be formed of metal films having different colors. According to this modification, a color display having a background pattern made of various metal reflected lights having different color purity, brightness, and color can be obtained.

Next, 4th Embodiment of this invention is described based on FIG.
On the inner surface of the rear glass substrate 2, a light reflecting film 16 is uniformly deposited with a constant film thickness. On the light reflecting film 16, a plurality of highly light transmissive films 17 made of a material having a high light transmittance are arranged in a predetermined arrangement in an island shape. As a material for the high light-transmitting film 17, a transparent metal film such as ITO (Indium Tin Oxide) or a transparent organic film such as an acrylic resin is preferably used. Then, the color filter layer 7 having a flat surface composed of the color elements 7r, 7g, and 7b of each color of red, green, and blue is covered by covering the high light-transmitting film 17 and the light reflecting film 16 exposed between them. It is formed. Here, the high light transmission film 17 and the color filter layer 7 laminated thereon have different refractive indexes. On the color filter layer 7, as in the first embodiment, a transparent protective film 8, a scanning electrode 9, and an alignment film 10 are sequentially stacked.

  In the fourth embodiment configured as described above, the thickness of the color filter layer 7 laminated differs between the area where the high light transmission film 17 is provided and the area where it is not provided. Accordingly, even if the light beam is incident on the red element 7r, the light beam A is incident on the thick red element 7r and reflected by the light reflecting film 16, so that it is formed on the surface of the high light transmitting film 17. Compared with the light beam B which is incident on the thin portion of the red element 7r, which is incident on the thin layer, is transmitted through the high light-transmitting film 17 and is reflected by the light reflecting film 16, it is dark red light having high color purity but low luminance. .

  The light rays A and B are incident on the alignment film 10 at the same incident angle. However, since the light rays B are subjected to the photorefractive action when passing through the high light-transmitting film 17, the light reflecting film 16 The incident angle is different from that of the light beam a that does not pass through the high light-transmitting film 17. Therefore, the direction reflected by the light reflecting film 16 is different between the light ray A and the light ray B.

  Therefore, both the light rays A and the light rays B are red light having different color purity, luminance, and emission direction even though the light is incident on the alignment film 10 from the same direction and passes through the red element 7r. As a result, according to the liquid crystal display device of the present embodiment, a color display having extremely various hues and unique viewing angle characteristics can be obtained. If a plurality of types of high light-transmitting films having different refractive indexes are provided as the high light-transmitting film 17, more various viewing angle characteristics can be obtained.

  Note that the present invention is not limited to the first to fourth embodiments described above. For example, the first reflective film and the second reflective film are not limited to metal films, but may be inorganic films such as ceramics, or organic films made of resin or the like.

  Further, the present invention can be applied to a liquid crystal display device for monochrome reflection display in which no color filter layer is provided. In this case, a black and white reflective display having a background pattern due to a difference in luminance can be obtained.

In addition, the present invention is not limited to the simple matrix type, and can be applied to various other liquid crystal display devices such as a segment type and an active matrix type.

1 is a schematic cross-sectional view showing a simple matrix liquid crystal display device as a first embodiment of the present invention. It is typical sectional drawing which shows the laminated structure of the back side glass substrate in the liquid crystal display device as 2nd Embodiment of this invention. It is typical sectional drawing which shows the laminated structure of the back side glass substrate in the liquid crystal display device as 3rd Embodiment of this invention. It is typical sectional drawing which shows the laminated structure of the back side glass substrate in the liquid crystal display device as 4th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Front side glass substrate 2 Rear side glass substrate 3 Display electrode 4 Black matrix 5, 10 Orientation film 6, 11, 16 Light reflection film 6a Underlayer 6b Surface end film 11a, 13 1st reflection film 11b, 15 2nd reflection film 7 , 12 Color filter layer 7g, 12g Green element 7b, 12b Blue element 8 Transparent protective film 9 Scanning electrode 14 Acid-resistant transparent film 17 High light-transmitting film

Claims (11)

A liquid crystal display device in which liquid crystal is sealed between a front substrate disposed on the observation side of the display and a rear substrate opposite to the display observation side;
A light reflecting film is disposed on a surface of the rear substrate facing the front substrate;
The liquid crystal display device, wherein the light reflecting film includes at least two kinds of light reflecting areas having different visual characteristics given to an observer of reflected light.   2. The liquid crystal display device according to claim 1, wherein a color filter layer comprising a plurality of color elements and having a substantially flat surface is laminated on the surface of the light reflecting film.   The liquid crystal display device according to claim 2, wherein a surface of the light reflecting film is uneven.   3. The liquid crystal display device according to claim 1, wherein the light reflecting film includes at least two types of light reflecting areas having different light reflectivities.   3. The liquid crystal display device according to claim 1, wherein the light reflecting film includes at least two types of light reflecting areas having different reflection angles with respect to an incident angle of light.   3. The liquid crystal display device according to claim 1, wherein the light reflecting film includes at least two kinds of light reflecting areas having different colors of reflected light.   3. The light reflecting film according to claim 1, wherein a plurality of second reflecting films are disposed in a scattered state on the first reflecting film having a constant film thickness. Liquid crystal display device.   The liquid crystal display device according to claim 7, wherein the first reflective film and the second reflective film have different light reflectivities.   The liquid crystal display device according to claim 7, wherein the first reflection film and the second reflection film have different reflection angles with respect to an incident angle of light.   The liquid crystal display device according to claim 7, wherein the first reflective film and the second reflective film have different colors of reflected light. 3. The liquid crystal display device according to claim 1, wherein the light reflecting film is formed by disposing a light transmissive film in a scattered state on a reflecting film having a constant film thickness.

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