JPH022132B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a color liquid crystal display device having a colored film inside the cell, and more particularly to a color liquid crystal cell in which the colored film is made of a transition metal oxide.

In a conventional color liquid crystal cell having a colored film inside the cell, a metal oxide is formed on a glass substrate by vacuum evaporation or sputtering. However, the vapor deposition method or the sputtering method has the disadvantage that it is expensive, and etching is required afterward to create a fine pattern, making the process complicated.

In order to eliminate the above-mentioned drawbacks when producing a color liquid crystal cell, the present invention uses a printing paste containing an organic transition metal compound that is soluble in an organic solvent. The formation method will be explained.

Organometallic compounds of elements belonging to groups a, a, a, and b of the periodic table with a boiling point of 200
Dissolved in organic solvents at temperatures of about A paste is prepared by adding and mixing a cellulose compound such as nitrocellulose or ethylcellulose as an agent. When this paste is screen printed onto a substrate such as glass and fired at a temperature of 400°C or higher, a beautiful colored film in the desired shape is formed. The colored film formed has different properties such as coloring state, resistivity, film strength, etc. depending on the type of metal of the organometallic compound used.

Examples of the liquid crystal cell according to the present invention will be described in detail below.

Example 1 FIG. 1 shows a sectional view of this example. A paste containing an organometallic complex of Fe〓(acac) ₃ coordinated with acetylacetone (Hacac) and using nitrocellulose as a viscosity agent was printed on one of the two insulating substrates 1, 1 and heated at 500℃. A yellow-orange colored film 2 is formed by firing. On this substrate and the other substrate, transparent electrodes 3, 3 made of indium oxide and oxide films 4, 4 made of SiO ₂ were formed thereon by a general method, and after horizontal alignment treatment was performed using a silane coupling agent,
After rubbing, a nematic liquid crystal GR-61 (manufactured by Chitsuso Corporation) having a positive dielectric anisotropy was sealed in the space 5 to form a twisted nematic (TN) liquid crystal cell.

In this cell, a black pattern appears when a voltage is applied to a yellow-orange background, and a color liquid crystal cell with good visibility can be formed, especially when used as a reflective display.

Example 2 In FIG. 1, one, for example, the lower insulating substrate 1 is made into a white substrate by the following method. In other words, a mixed paste containing organometallic compounds such as aluminum and indium and fine white powder such as alumina or titanium oxide is applied onto a glass substrate, pre-dried, and then fired in a furnace at around 500°C to form a glass substrate. A white film is formed on top, forming a white substrate. On this white substrate, a paste containing an organometallic complex of Cr〓(acac) ₃ and using nitrocellulose as a viscous agent was printed and baked at 500℃ to form a green colored film on the part 2 in Figure 1. Form. After forming transparent electrodes 3, 3 of indium oxide on this substrate and the other transparent substrate and oxide films 4, 4 of SiO ₂ thereon by a general method, a silane coupling agent is applied.
Vertical alignment treatment using DMOAP (manufactured by Chitsuso Corporation)
Assemble the liquid crystal cell. blue pigment in this cell
Nematic liquid crystal EN30 (manufactured by Chitsuso) with negative dielectric anisotropy containing 1wt% of D5 (manufactured by BDH) and 1.5wt% of chiral nematic liquid crystal CM20 (manufactured by Chitsuso)
If it is sealed in 5 in FIG. 1, it becomes a positive display phase change type guest host cell. The pale blue color when no voltage is applied when the colored film 2 is not applied overlaps with the pale green colored film, and the background color appears to be close to white. This cell has a blue pattern when voltage is applied, and a color close to white when no voltage is applied, resulting in a positive display with good visibility.

Example 3 A paste containing an organometallic complex of Mn〓(acac) ₃ and using nitrocellulose as a viscous agent was printed on one of the two insulating substrates, an opaque white substrate, and baked at 500°C. and forms a brown to black colored film. On this substrate and the other transparent substrate, a transparent electrode of indium oxide and an oxide film of SiO ₂ are formed on it by a general method, and then vertical alignment treatment is performed using a silane coupling agent DMOAP (manufactured by Chitsuso Corporation) to form a liquid crystal. Assemble the cells. A nematic liquid crystal N-31 (manufactured by Chitsuso Corporation) having negative dielectric anisotropy to which 0.05 wt % of ion doping agent TBAB (tetrabutylammonia bromide) was added was sealed in this cell.
When a voltage is applied, it becomes a color liquid crystal cell in which a white pattern scattered by the dynamic scattering mode appears on a brown to black background.

Example 4 Cr〓(acac) ₃ , Fe〓(acac) ₃ , Co〓(acac) ₂ green, on one side of two insulating substrates, at least one of which is transparent.
Three colored metal oxide films: yellow-orange and brown Y ₁ , Y ₂ , Y ₃
are formed in order in regular stripes, and 3n transparent electrodes of indium oxide are formed in stripes on the colored films Y ₁ , Y ₂ , Y ₃ along the pattern using a general method. On the other substrate, n transparent electrodes X are formed in stripes at the same pitch. A SiO ₂ insulating film is formed on both of these substrates using a general method, horizontally aligned using a silane coupling agent, and then rubbed. Polarizing plates are pasted on the front and back of the cell, and the so-called TN Assemble the cells. Note that the stripes of transparent electrodes superimposed on the colored films Y ₁ , Y ₂ , and Y ₃ are assembled so that they are orthogonal to the transparent electrode on the other substrate. Figure 2 shows the state of the colored film seen from above the transparent substrate.
The j-th colored film Yj ₁ formed on one substrate,
This is an enlarged view of the intersection between one set of Yj ₂ and Yj ₃ and the i-th transparent electrode Xi on the other substrate. If you want to display the desired position of this cell in the desired color, apply voltage to the stripes appears. If you apply voltage to the stripes X and Y so that a color close to the desired color appears in the three color areas that make up the unit picture element shown in Figure 2 where you want to display,
A multi-color liquid crystal display cell is obtained.

Example 5 In this example, at least one of two substrates is a transparent substrate, and one of the substrates is coated with three colored coatings X ₁ , X ₂ , and X _{3 .}
and a colored film consisting of the same combination on the other side.
Y ₁ , Y ₂ , and Y ₃ are arranged perpendicularly to the above-mentioned X ₁ , X _{2 ,} and In the figure, the ith of X..., Y... (i.e. Xi ₁ , Xi ₂ ,
Xi ₃ ) and the j-th (ie, Yj ₁ , Yj ₂ , Yj ₃ ) intersection position. Cr on both boards
(acac) ₃ , Fe (acac) ₃ , Co〓 (acac) ₂ green, yellow-orange,
3n colored metal oxide films of three colors of brown are formed regularly in stripes in order, and on these stripes,
3n indium oxide NESA films are formed along the pattern using a general method, and a SiO ₂ film is further formed on the entire surface using a vacuum evaporation method. These two substrates are vertically aligned using a silane coupling agent SH6040 (Toray Silicone) and then rubbed in the stripe direction. A cell is assembled so that the stripes on these two substrates are perpendicular to each other, and a nematic liquid crystal with positive dielectric anisotropy is created by adding dichroic black dye inside the cell.
Enclose ROSA653 (manufactured by Rotsuyu Co., Ltd.), attach one polarizing plate so that the polarization axis is parallel to one stripe, and use it as a transmission type. If you want to produce a certain color among the nine points that make up the picture element in Figure 3, you can apply a voltage to the upper and lower electrodes corresponding to that point, and the overlapping color of the upper and lower colored films at that point will be changed. Points that are not applied are shown in black. A multicolor liquid crystal display can be obtained by applying voltages to the stripes X and Y so that a color close to the desired color appears at nine points in the unit picture element shown in FIG. 3 as a whole.

As described above, the liquid crystal cell on which a colored film is formed according to the present invention can be applied to various color liquid crystal displays to improve visibility, etc., as described above, and the field of application thereof is wide. It is extremely wide.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a liquid crystal display cell according to an embodiment of the present invention, FIG. 2 is a plan view of a main part showing the arrangement shape of picture elements formed by a striped colored film in another embodiment, and FIG. 3 is a further another embodiment. FIG. 2 is a plan view of essential parts of a colored film picture element in an example. 1... Insulating substrate, 2... Colored metal oxide film, 3...
Transparent electrode, 4... oxide film subjected to orientation treatment, 5...
liquid crystal substance.

Claims (1)

[Claims] 1. A color liquid crystal display device in which a liquid crystal is sealed between two insulating substrates, and a colored film made of a metal oxide is formed on the inner surface of one of the insulating substrates, wherein the colored film is arranged in the periodic table a and a. , a, and b
A color characterized in that it is formed by printing and baking a printing paste obtained by dissolving an organometallic compound of at least one metal belonging to any one of the groups and a viscosity agent of a cellulose compound in a high boiling point organic solvent. LCD display device.