JP3214742B2 - Liquid crystal display - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device using a liquid crystal / polymer composite film having an electric field and thermal response and capable of displaying and recording information. Can be widely applied to character information displays, image information displays, measurement meters, and the like.

[0002]

2. Description of the Related Art Conventionally, a liquid crystal display has characteristics such as low power consumption, light weight and thinness, and thus has been widely used as a display medium for characters and images in watches, calculators, personal computers, televisions, and the like. . General, TN- and ST
The N-liquid crystal display has a structure in which liquid crystal is sealed in a liquid crystal cell in which a predetermined seal or the like is provided between glass plates having transparent electrodes, and is further sandwiched by polarizing plates from both sides. However, these liquid crystal displays require (1) a backlight having high power consumption because of a narrow viewing angle and insufficient brightness because two polarizing plates are required, and (2) a cell thickness. (3) There is a problem that the structure is complicated and the manufacturing cost is high, and the liquid crystal display is reduced in weight, thickness, increased in area, reduced in power consumption, and reduced in cost. Has limitations.

As a liquid crystal display device which solves such problems, application of a liquid crystal / polymer composite film in which liquid crystal is dispersed in a polymer matrix is expected, and research and development thereof have been activated. The main configuration of such a liquid crystal display device is a combination of a liquid crystal / polymer composite film layer sandwiched between transparent electrode substrates and a reflector or a background plate. The technique described in Japanese Patent Application Laid-Open (JP-A) No. 3-175421 can be used as a technique for utilizing the cloudiness caused by the above.

[0004]

Problems of the prior art relating to the liquid crystal display include the following. (1) In the light scattering state of the liquid crystal / polymer composite film, the reflection plate can be seen through the cloudy liquid crystal / polymer composite film layer. Or it looks colored by the color of the background plate. If the thickness of the liquid crystal / polymer composite film is increased in order to prevent these by increasing the scattering intensity, the driving voltage will increase. (2) In order to prevent coloring by the background plate, if the device is configured to have a space between the liquid crystal / polymer composite film layer and the background plate, a portion corresponding to the display pattern adjacent to the background plate or the reflection plate depending on the viewing angle. , The wide viewing angle characteristic of the liquid crystal / polymer composite film cannot be fully utilized. Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art and to display a clear image with a wide viewing angle and no color mixing without increasing the thickness and driving voltage of the liquid crystal / polymer composite film. It is to provide a liquid crystal display device capable of performing the above.

[0005]

The above object is achieved by the present invention described below. That is, the present invention relates to a liquid crystal display device including a pair of electrode substrates, a liquid crystal / polymer composite film sandwiched between the pair of electrode substrates, and a background plate or a reflection plate provided on the back surface of one of the electrode substrates. The surface of the plate or reflector is formed into a curved or square shape consisting of a wall and a bottom
And the wall is at the boundary of each pattern of the liquid crystal display device.
A liquid crystal display device, which is coincident .

[0006]

According to the present invention, a barrier having an appropriate height is formed at the boundary of each pattern of the background plate or the reflection plate by the above structure, and preferably, the inner surface is colored to the same hue as the display color of the pattern. By arranging this at an appropriate distance on the back surface of the liquid crystal / polymer composite film, it is possible to eliminate the influence of the display color of the adjacent pattern in each pattern,
It is possible to provide a liquid crystal display device capable of displaying a clear image with a wide viewing angle and no color mixture without raising the thickness of the liquid crystal / polymer composite film and the driving voltage.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be specifically described with reference to preferred embodiments shown in the drawings. 1A is a plan view schematically showing a liquid crystal display device of the present invention, FIG. 1B is a partially enlarged sectional view taken along the line AA of FIG. 1A, and FIG. 1C is a partially enlarged sectional view of another embodiment. It is.

As shown in the figure, the liquid crystal display device of the present invention is provided on a pair of electrode substrates 1 and 1 ', a liquid crystal / polymer composite film 2 sandwiched between the pair of electrode substrates 1 and 1', and on the back surface of one of the electrode substrates 1 '. In the liquid crystal display device including the background plate or the reflection plate 3, the surface of the background plate or the reflection plate surface 3 is formed in a curved shape or a square shape 5 corresponding to each pattern 4 of the liquid crystal display device. It is characterized by. The electrode substrates 1 and 1 ′ according to the present invention are the same as the electrode substrates of a conventionally known liquid crystal display device.
It is a transparent substrate such as a glass or a polymer film provided with transparent conductivity such as O, SnO ₂ and ZnO.

As the liquid crystal / polymer composite film used in the present invention, any conventionally known liquid crystal / polymer composite film may be used. For example, polyvinyl alcohol (PVA) or a crosslinked product thereof may be prepared by an emulsion method. Liquid crystal / polymer composite film formed as matrix, liquid crystal / polymer composite film formed using epoxy resin, ultraviolet curable resin, electron beam curable resin, acrylic resin, cellulose acetate resin, etc. as matrix by phase separation method Any liquid crystal / polymer composite film may be used. Further, the liquid crystal dispersed in the matrix resin is an organic mixture showing a liquid crystal state at around normal temperature, a nematic liquid crystal,
Cholesteric liquid crystals and smectic liquid crystals are included. Among them, nematic liquid crystals or nematic liquid crystals to which cholesteric liquid crystals are added, and those obtained by microencapsulating these liquid crystals can be used.

[0010] In order to improve the contrast or color tone of the liquid crystal, a dye may be contained. When a dichroic dye is added, it can be used not only as a scattering-transmission type composite film, but also as a composite film that switches between light absorption (coloring) and a transparent state due to the guest-host effect of the dye. . The usage of these liquid crystals
Matrix resin / liquid crystal mixture ratio (weight ratio) is 5 / 95-
When the amount of the liquid crystal used is too small, the transparency at the time of turning on the voltage is insufficient, and in addition, a large voltage is required to make the film transparent. On the other hand, if the amount of the liquid crystal used is too large, not only scattering (turbidity) at the time of turning off the voltage is insufficient, but also the strength of the film is reduced, or a coating liquid is applied to an appropriate substrate. It is not preferable because it sometimes causes playing. The thickness of these liquid crystal / polymer composite films is generally about 5 to 10 μm.

The background plate or reflecting plate 3 which mainly characterizes the present invention is formed from a glass, a metal plate, a synthetic resin or the like by a general forming technique. For example, thermoplastic resin polymethyl methacrylate (thickness of about 75 to 125 μm
By heating and embossing the plate, a desired curved shape or square shape 5 corresponding to the pattern 4 of the liquid crystal display device can be provided. Such a background plate or the reflection plate 3 is interposed between the one electrode surface of the liquid crystal display device at a certain distance, for example, a distance from the bottom of the concave portion of the background plate or the reflection plate 3 to several mm, and is interposed through the spacer 10. They are joined Te.

A bay provided on the surface of the background plate or reflector 3
As shown in FIGS. 1B and 1C, the curved or square-shaped shape 5 has a concave portion 6 corresponding to the size and shape of each pattern 4 of the liquid crystal display device.
Match In the embodiment shown in FIG. 1a, bay Kyoku凹 portion 6 facing the respective pattern 4 is formed, the boundary of each bay Kyoku凹 unit 6 is coincident with a wall portion 7 on the boundary of each pattern 4 . Such a background plate or a reflection plate 3 serves as one electrode substrate 1 '.
By being arranged on the side, the visible light rays 9 reflected / emitted from each pattern 4 are limited to the visible light rays of the hue of the pattern 4, and the hues of the adjacent patterns are not mixed due to parallax. In this case, it is colored display hue and the same color of the pattern on the surface thereof to the inner surface of the bay Kyoku凹 section 6 (e.g., Y, Bk, B, C, M, etc.) and, further display hue and sharpness Become.

In the example shown in FIG. 1C , the square shape 5 is
This is an example in which the shape is a square shape composed of a wall portion 7 and a bottom portion 8, and the wall portion 7 matches a boundary portion between the patterns 4. In this case as well, it is preferable to provide the same operation and effect as described above, and to similarly color the inner surface of the square (for example, Y, Bk, B, C, M, etc.). The method of providing the curved shape or the square shape 5 on the surface of the background plate or the reflecting plate 3 is preferably an arbitrary curved shape or square shape by embossing when the background plate or the reflecting plate 3 is made of plastic or the like. 5 can be easily formed, and the concave portion 6 can be colored simultaneously with the embossing process by applying coloring ink to the convex portion of the embossing roll. According to injection molding,
Any thermoplastic resin (e.g., A acrylate resins, polycarbonate resins, polystyrene, ABS resin, etc.) previously loaded can be formed from, in advance in the mold to match the transfer film to the molding die in this case Thereby, a desired portion of the background plate or the reflecting plate 3 can be colored to an arbitrary hue at the same time as molding.

When the background plate or the reflection plate 3 is a metal plate, an etching technique or the like can be used in addition to the similar embossing process. In addition, as a method of providing the curved shape or the square shape 5, as described above, the curved shape or the square shape is used.
The background plate or reflection plate 3 on which the shape 5 is formed is used as a molding die, for example, a photocurable resin is applied thereto, a transparent film is laminated on the application surface, the resin is photocured, and the background used as the mold is used. It can also be formed by peeling off from the plate or the reflection plate 3. The depth of the curved portion or concave portion 6 of the background plate or the reflecting plate 3 formed in this way is adjusted by the thickness of the liquid crystal / polymer composite film and the distance from the liquid crystal display device.
Generally, about 2-3 mm is preferable.

[0015]

According to the present invention as described above, even when the thickness of the liquid crystal / polymer composite film is reduced in order to reduce the driving voltage, a pattern having an arbitrary shape which is not affected by the adjacent pattern can be formed. Since it can be configured, it is possible to provide a display device which does not impair the wide viewing angle characteristic which is a feature of the liquid crystal / polymer composite film. On the other hand, when the display device is configured with a flat background plate or a reflection plate which is generally used in the related art, when the selected pattern is made transparent, the display content corresponding to the adjacent pattern may be changed depending on the viewing angle. Appears and display quality is remarkably low.

[0016]

[Brief description of the drawings]

FIG. 1 is a diagram schematically illustrating a configuration and an effect of a display device of the present invention.

[Explanation of symbols]

1, 1 ': a pair of electrode substrates 2: a liquid crystal / polymer composite film 3: a background plate or a reflection plate 4: a pattern 5: a curved shape or a square shape 6: a curved portion or a concave portion 7: a wall portion 8: a bottom portion 9: Visible light 10: Spacer

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Masayuki Ando 1-1-1, Ichigaya-Kaga-cho, Shinjuku-ku, Tokyo Inside Dai Nippon Printing Co., Ltd. (56) References JP-A-2-3011 (JP, A) ( 58) Field surveyed (Int.Cl. ⁷ , DB name) G02F 1/1334 G02F 1/1335 520

Claims (2)

(57) [Claims] 1. A liquid crystal display device comprising a pair of electrode substrates, a liquid crystal / polymer composite film sandwiched between the pair of electrode substrates, and a background plate or a reflection plate provided on a back surface of one of the electrode substrates. or the surface of the reflection plate, it from the wall portion and the bottom portion
A liquid crystal display device, wherein the wall portion is formed in a curved shape or a square shape, and the wall portion coincides with a boundary portion of each pattern of the liquid crystal display device. 2. The liquid crystal display device according to claim 1, wherein the inner surface of the curved or square shape is colored in the same color as the display color of the corresponding pattern.