JPS6249325A - Liquid crystal display element - Google Patents

Abstract

PURPOSE:To improve productivity and to prevent moisture resistance from reduction by forming coloring layers containing a diffusing agent in contact with the lower surface of a low polarizing plate. CONSTITUTION:The 1st coloring layer 12, a diffusing layer 13 and the 2nd coloring layer 14 are successively laminated in contact with the lower surface of the lower polarizing plate 8. The coloring layer 12 is formed by printing the mixture of a coloring agent, a diffusing agent and a bonding agent and drying these agents. Since the coloring layers are formed in contact with the lower surface of the lower polarizing plate, the loss of reflected light due to reflection is not generated between the lower polarizing plate and the coloring layers and clear color display can be attained in relfection type display. Since the coloring layers are directly formed on the lower polarizing plate, the number of parts can be reduced and the productivity is also improved. The display element is prevented from moisture infiltration into the gap between the lower polarizing plate and the coloring layers, so that its moisture resistance is also improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a color liquid crystal display element having a colored layer on the lower surface of a lower polarizing plate.

"Prior Art and its Problems" Conventionally, for example, a twisted nematic type (hereinafter referred to as TN type) liquid crystal display element is known in which a colored film is provided on the lower surface of a lower polarizing plate in order to display color.

FIGS. 3 and 4 show specific examples of the above-mentioned TN type color liquid crystal display element. That is, an upper substrate 2 with display electrodes 1 formed on the inner surface and a lower substrate 4 with counter electrodes 3 formed on the inner surface are arranged facing each other, and their peripheral edges are fixed with a sealing material 5, and a TN type is formed inside. Liquid crystal 8 is injected. Polarizing plates 7.8 are attached to the outer sides of the upper substrate 2 and the lower substrate 4, respectively. A colored film 9, in which colored films 8 are disposed at predetermined intervals on the lower surface of the lower polarizing plate 8, is made up of a transparent film 1O and a colored layer 11 formed on the upper surface of this film 10. The resin component in the fluorescent pigment is contained in the colored layer 11 as a diffusing agent.

In this color liquid crystal display element, external light can be reflected by the colored film 9 to perform a reflective display, or a light source placed on the rear side can perform a transmissive display. Since the reflected light and the transmitted light are colored by the colored film 9, color display is possible.

However, in the conventional color liquid crystal display element described above, when performing reflective display, as shown in FIG.
After the light beam is reflected by the colored layer 11 of the colored film 3,
There is a problem in that the light is re-reflected on the lower surface of the lower polarizing plate 8, causing a loss of light, and the reflected light that contributes to display becomes dark, resulting in a decrease in visibility due to the so-called "0 washout" phenomenon. Since the colored film 9 is supported at a predetermined distance from the polarizing plate 8, three structural members are required, including a means for fixing the glass colored film with a polarizing plate with a gap of 10, which increases parts cost and complicates the structure. Productivity was also poor.Furthermore, moisture etc. easily entered between the lower polarizing plate 8 and the colored film 9, resulting in low moisture resistance.

``Object of the Invention'' In view of the problems of the prior art described above, the object of the present invention is to clarify the color display in the reflective type, reduce the number of parts, improve productivity, and provide a color display that does not reduce moisture resistance, etc. An object of the present invention is to provide a liquid crystal display element.

"Structure of the Invention" The present invention provides a liquid crystal display element in which a liquid crystal is sealed between at least upper and lower substrates facing each other, and polarizing plates are provided on the outside of the upper and lower substrates. It is characterized by forming a colored layer containing.

In this way, since the colored layer is formed in contact with the lower surface of the lower polarizing plate, there is no loss of reflected light due to re-reflection between the lower polarizing plate and the colored layer, making it clear in reflective display. Displayed in color.

Furthermore, since the colored layer is directly formed on the lower polarizing plate, the number of parts can be reduced and productivity can be improved. Furthermore, since moisture does not enter between the lower polarizing plate and the colored layer, moisture resistance is also improved.

In the present invention, the upper substrate means the substrate on the display side, and the lower substrate and lower polarizing plate mean the substrate and polarizing plate on the back side.

"Embodiments of the Invention" FIGS. 1 and 2 show embodiments of a color liquid crystal display element according to the present invention. In addition, Figures 3 and 4
Components that are substantially the same as those of the color liquid crystal display element shown in the drawings will be given the same reference numerals and their description will be omitted.

In this color liquid crystal display element, a first colored layer 12, a diffusion layer 13, and a second colored layer 14 are sequentially laminated in contact with the lower surface of the lower polarizing plate 8.

The colored layer 12 is formed by, for example, printing a mixture of a coloring agent, a diffusing agent, and a binder and drying it.

In this case, the coloring agent used is Burr pigment, fluorescent pigment, color dye, etc., and the diffusing agent is polymer fine powder,
A white pearl pigment or the like is used, and as a binder, a vinyl chloride resin, a vinyl chloride-acrylic copolymer resin, a vinyl chloride-vinyl acetate copolymer resin, or the like is used. The content of the diffusing agent in the binder is preferably 0.5 to 7% by weight, more preferably 0.5 to 5%, and 0.5 to 3%.
is the most preferable. If the content of the diffusing agent is less than 0.5%, there will be a problem that sufficient reflection cannot be obtained, and if it exceeds 7%, there will be a problem that the color tone will change due to the diffusing agent. Further, the thickness of the colored layer 12 is preferably 3 to 20 μm, and 5 μm to 20 μm.
-15 ILll is more preferable.0 If the thickness of the colored layer 12 is less than 3 μm, there will be a problem that sufficient reflection and diffusion cannot be obtained, and if it exceeds 20 pm, there will be a problem that the brightness in the transmission state will be insufficient.

The diffusion layer 13 is a colorless layer for adjusting light transmittance when a transmission type is used, and is formed by, for example, applying a mixture of a diffusion agent and a binder and drying it. As the diffusing agent, the same ones as mentioned above are used. In addition, the second colored layer 1
4 is a layer for adjusting color tone when using a transmission type, for example, a mixture of a colorant and a binder is applied,
As the coloring agent formed by drying, the same ones as mentioned above are used. In addition, in the present invention, the diffusion layer 13 and the second M color layer 14 are formed as necessary, and do not need to be provided in particular.
The colored pattern of the second colored layer 14 is printed so as to form a predetermined pattern depending on the pattern of the display electrodes l.

In this color liquid crystal display element, when negative type reflective display is performed, external light incident from the display surface is reflected by the first colored layer 12. Then, one reflected light becomes a predetermined color by the coloring agent of the first colored layer 12, and is transmitted from the portion where voltage is applied between the electrodes 1 and 3, thereby producing a negative type color display.

In this case, there is no loss of light due to re-reflection between the first colored layer 12 and the lower polarizing plate 8, so a clear display can be achieved. Further, when a negative type transmission type display is performed using this color liquid crystal display element, a light source is installed on the back side. The light from the light source is colored M14. The light passes through the diffusion layer 13 and the first colored layer 12 in order to obtain a predetermined color, and further passes through the portion where voltage is applied between the electrodes 1 and 3, producing a negative type color display.

"Effects of the Invention" As explained above, according to the present invention, a colored layer containing a diffusing agent is formed in contact with the lower surface of the lower polarizing plate, so that reflected light is Since there is no loss due to re-reflection between the colored layer and the lower polarizing plate, a 2g brighter display can be achieved. Furthermore, since the colored layer is formed integrally with the lower polarizing plate, the number of parts can be reduced, and productivity can be improved. Furthermore, since moisture does not enter between the first colored layer and the lower polarizing plate, #humidity is also improved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of a color liquid crystal display element according to the present invention, FIG. 2 is a partially enlarged sectional view of the same color liquid crystal display element, and FIG. 3 is a sectional view showing an example of a conventional color liquid crystal display element. , FIG. 4 is a partially enlarged sectional view of the same color liquid crystal display element. In the figure, l is a display electrode, 2 is an upper substrate, 3 is a counter electrode, 4 is a lower substrate, 5 is a sealant, 6 is a liquid crystal, 7 is an upper polarizing plate, 8 is a lower polarizing plate, 12 is a first colored layer , 13 is a diffusion layer, and 14 is a second colored layer.

Claims (1)

[Claims] At least a liquid crystal is sealed between upper and lower substrates facing each other,
A liquid crystal display element in which polarizing plates are provided on the outside of the upper and lower substrates, characterized in that a colored layer containing a diffusing agent is formed in contact with the lower surface of the lower polarizing plate.