JPH0437719A - Color liquid crystal panel and its manufacture - Google Patents

Abstract

PURPOSE:To prevent the black state of the color liquid crystal panel from becoming blueish and to improve the color display quality of the color liquid crystal panel by making a liquid crystal layer different in twist angle or pretilt angle among positions corresponding to the respective colors of color filters. CONSTITUTION:An orienting film 28 has an orienting direction at a uniform angle of, for example, 35 deg. to rays X parallel to one side of the panel. An orienting film 27 facing the orienting film 28, on the other hand, has different orienting directions at positions corresponding to the color filters R, G, and B. Namely, the twisting angle is made large for blue(B) which is high in threshold voltage when the twisting angle is equal and the twisting angle is made small for red(R) which is low in threshold voltage when the twisting angle is equal to make the threshold voltages of red, green, and blue nearly equal. Consequently, the quantities of transmitted light becomes equal among the respective colors and the black state does not turn bluish.

Description

[Detailed Description of the Invention] [Summary] Regarding a color liquid crystal panel and a method for manufacturing the same, the purpose is to improve the color reproducibility of a color liquid crystal panel using a color filter. with R,G
, B, in a liquid crystal panel that performs color display using color filters, the portion corresponding to R of the color filter, G
It has a structure in which the twist angle or pretilt angle of the liquid crystal in the part corresponding to B and the part corresponding to B are made different so that the amount of transmitted light of each color is equal. A resist is applied to the liquid crystal layer side of one of the transparent insulating substrates sandwiching the transparent insulating substrate, and the resist in the area corresponding to a certain color is peeled off by exposure, and a color filter of a certain color is applied or printed on the peeled part and the remaining resist. and laminating an electrode on the substrate, and depositing SiO as an alignment film on the substrate in this state, diagonally with respect to the normal direction of the substrate and at a predetermined angle with respect to a certain side of the substrate. The first step consists of a step of vapor depositing the resist, a color filter, an electrode, and an alignment film stacked on the substrate, and a step of removing the laminate of the resist, color filter, electrode, and alignment film stacked on the substrate. the vapor deposition angle is the same with respect to the normal direction of the substrate, and the vapor deposition angle with respect to a certain side of the substrate is different; The step of making the angle different for each color can be changed to the step of applying a rubbing treatment in the alignment direction corresponding to each color after coating the alignment film on the substrate.

[Industrial application field]

The present invention relates to a color liquid crystal panel and a method for manufacturing the same.

In recent years, liquid crystal display devices, which are lightweight, thin, and can be powered by batteries, have been increasingly used as display devices for personal computers, word processors, and the like, instead of CRTs, which are large and consume a lot of power. In this liquid crystal display device, there is an increasing demand for a color display instead of a black and white display, and furthermore, a high quality color display is also required.

[Conventional technology]

By the way, on the liquid crystal panel of a color liquid crystal display device, red (
The polarization direction of each color of light (R), blue (G), and green (B) can be changed by the birefringence of the liquid crystal, and the magnitude is Δn−d
/λ, so blue light with a shorter wavelength has a greater effect. For this reason, there is a problem in that blue light sensitively reacts to changes in birefringence, that is, changes in the alignment of liquid crystals, and when a voltage is applied to a color liquid crystal panel, blue light is transmitted first, giving it a bluish tint.

This means that if the liquid crystal of each color is placed under the same conditions, that is, the liquid crystal has a constant pretilt angle and twist angle, the transmittance of each color (
The T)-voltage (V) characteristic is as shown in FIG. 14, and the transmittance of blue light increases even when the voltage is low, so the amount of blue light transmitted increases.

Conventionally, a countermeasure called multi-gap has been taken to deal with such problems. This multi-gap method
As shown in FIG. 3, a liquid crystal layer 131 is formed on a glass substrate 1 on which an alignment film 132 and a transparent electrode (IT 0) 133 are laminated.
In the liquid crystal panel sandwiched by 34, one IT 01
A color filter 135 of three colors R, G, and B is inserted between the glass substrate 134 and the glass substrate 134, and its thickness is B, G, and R.
The thickness d of the blue liquid crystal cell layer is made small and the thickness d of the red liquid crystal cell layer is made large. That is, in this method, the thickness of the liquid crystal cell layer of each color is adjusted to d++ < d according to the wavelength lengths of blue, green, and red light, λ8 〈λ, 〈λ8
c < dR, and set the ΔL・d/λ value of each color to λ8
λ6 λ, which is approximately constant regardless of the wavelength, and the amount of light transmitted through the liquid crystal panel is made constant for each color.

(Problem to be Solved by the Invention) However, with this conventional method, there is a problem in that it is quite difficult to make the thickness of the color filter different for each color.This is due to the required thickness of the color filter. The accuracy is approximately 0.1°, and it is difficult to maintain this accuracy by forming color filters by coating resin.

An object of the present invention is to solve the above-mentioned conventional problems in color liquid crystal panels, and to be able to more easily and reliably control the amount of transmitted light of each color in the color liquid crystal panel.
To improve the color display quality of a color liquid crystal panel by making the amount of transmission of each color substantially constant and preventing the black state of the color liquid crystal panel from becoming bluish.

[Means to solve the problem]

The structure of a color liquid crystal panel of the present invention that achieves the above object is shown in FIG. As shown in this figure, in the present invention, a plurality of transparent electrodes (data electrodes 2
In a liquid crystal panel that performs color display using color filters 4 of three colors RG and B, the color filter 4 has a portion corresponding to R, a portion corresponding to G, and a portion corresponding to B. A color liquid crystal panel is constructed by varying the twist angle or pretilt of the liquid crystal in the corresponding portions so that the amount of transmitted light of each color is equal.

This color liquid crystal panel is manufactured by applying a resist to the liquid crystal layer side of one of the transparent insulating substrates sandwiching the liquid crystal layer, and peeling off only the portion corresponding to a certain color by exposing this resist, and removing the peeled portion and the remaining resist. A color filter of a certain color is provided by coating or printing on the substrate, and an electrode is laminated thereon. SiO is applied as an alignment film on the substrate in this state, diagonally with respect to the normal direction of the substrate, and in the direction of the substrate. A first step consisting of a step of vapor deposition at a predetermined angle with respect to a certain side, and a step of removing the stack of resist, color filter, electrode, and alignment film stacked on the substrate from the substrate. Then, repeat the above process for each of the remaining two colors to create S
The deposition angle of iO with respect to the normal direction of the substrate is the same, and the deposition angle with respect to a certain side of the substrate is different.
, and the third step. Note that the step of depositing SiO as an alignment film on the substrate on which the electrodes are stacked is oblique to the normal direction of the substrate and at a predetermined angle to a certain side of the substrate. It is also possible to apply the alignment film on the laminated substrate, and then perform a rubbing process in the alignment direction corresponding to each color after the coating.

[Function] According to the color liquid crystal panel of the present invention, by varying the twist angle or pretilt angle of the liquid crystal layer in the portion corresponding to each color of the color filter, the Δn of the liquid crystal layer in the portion corresponding to each color of the color filter is changed. Since the value of -d/λ is approximately the same for all colors and the value of the threshold voltage is approximately the same, there is no difference in the amount of transmitted light for each color of red, green, and blue. As a result, it becomes possible to change the black level from a bluish color to an achromatic color, improving color reproducibility.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 2 is a sectional view showing the structure of a color liquid crystal panel 20 according to an embodiment of the present invention. In the color liquid crystal panel 20 of this embodiment, the liquid crystal layer 21 is formed on two substrates 20A, the first and second substrates.
, 20B. The first substrate 20A includes a glass substrate 25 and an ITO 23 serving as a scanning electrode.
and an alignment film 28, and the ITO 23 and the alignment film 28 are laminated in this order inside the glass substrate 26. Second
The substrate 20B consists of a glass substrate 25, R, G, and B color filters 24, ITO 22 serving as data electrodes, and an alignment film 27.The color filter 24 is first provided on the glass substrate 25, and this color filter Separate ITO layers 27 for each color of R, G, and B are laminated on the ITO layer 24, and an alignment film 27 is laminated thereon.

The alignment film 28 in this embodiment has an alignment direction isx parallel to one side of the panel as shown in FIG.
For example, it has 356 uniform angles.

On the other hand, the orientation film 27 facing the orientation film 28 has different orientation directions at the portions corresponding to the color filters R, G, and B, as shown in FIG.

For example, the alignment film 27 in the portion corresponding to color filter R has an angle of 25° with respect to the line Y parallel to the aforementioned line , B has an angle of 45°. This is because the alignment angle of the liquid crystal corresponding to G is made line symmetrical with the alignment angle of 35° in the alignment film 28 in consideration of symmetry.

Therefore, the twist angle φ8 of the liquid crystal in the portion corresponding to the color filter 270B (blue) is 3 as shown in FIG.
5°+180°+45°=260°. Similarly, the twist angle φ of the liquid crystal at the portion corresponding to G (green) of the color filter 27. becomes 250°, and the R of the color filter 27
The twist angle φ8 of the liquid crystal in the part corresponding to (red) is 240
It becomes °. Figure 5 shows T-V depending on the twist angle of green light.
It shows the characteristics.

As can be seen from this figure, the smaller the twist angle, the more T-
The threshold voltage of the V characteristic becomes lower. Therefore, when the twist angle is the same, the twist angle is set larger for blue (B), which has a high threshold voltage, and when the twist angle is the same, the twist angle is set smaller for red (R), which has a low threshold voltage. By doing so, the threshold voltages for each color of red, blue, and blue will be almost the same.

As explained above, in the color liquid crystal panel 20 of the present invention, since the threshold (I!if pressure) of each color of red, green, and blue is almost the same, the amount of transmitted light for each color is equal, and the black state becomes bluish. It's not expensive.

Next, a method of manufacturing a color liquid crystal panel by changing the twist angle corresponding to each color of the color filter 27 as described above will be described. In this manufacturing method, the second substrate 20B is manufactured through three steps, first to third.

First, in the first step, a resist 62 is applied onto a glass substrate 61 as shown in FIG. is removed by exposure (buttering),
The state shown in FIG. 6(b) is established. Subsequently, as shown in FIG. 6(C), an R color filter layer 63 is formed thereon, and ITO 65 is further laminated thereon. Then, SiO is diagonally deposited on the ITO 64 of the substrate in this state. This state is shown in FIG. 6 (6). As shown in FIG. 8, the method of diagonally depositing SiO is to eject SiO from a shrinkage source 81 linearly through a slit hole 82 and deposit it onto an obliquely inclined substrate 83. Good. After this, the glass substrate 6 is removed by a method called lift-off.
When the portion of the resist 62 remaining at
) is created.

Next, in the second step, as shown in FIG. 7(a), a resist 62 is again applied onto the glass substrate 61, and then,
Only the portion of the resist 62 corresponding to the next color (for example, C) of the color filter is removed (patterned) by exposure to form the state shown in FIG. 7(b). Subsequently, as shown in FIG. 7(C), a G color filter layer 63 is formed thereon, and a TO 64 is further laminated thereon. Then, SiO is obliquely vapor-deposited on the IT○64 of the substrate in this state. This state is shown in FIG. 6(d). Note that the in-plane direction of SiO vapor deposition at this time is different from that in the first step shown in FIG. This can be achieved by rotating the substrate 83 within its plane while keeping the angle of the substrate 83 the same in FIG. Thereafter, the portions of the resist 62 remaining on the glass substrate 61 and the alignment film 65 are removed by a quick-off process, creating the state shown in FIG. 7(e).

Furthermore, in the third step, the steps shown in FIGS. 7(a) to (e) may be repeated to form a B color filter layer instead of the G color filter layer. Further, the in-plane direction of SiO vapor deposition is made different from that in the first and second steps shown in FIGS. 6 and 7. This can also be realized by rotating the substrate 83 within its plane while keeping the angle of the substrate 83 the same in FIG.

Then, the second substrate 20B made by the above manufacturing method and the first substrate 2O made by the normal manufacturing method.
If the liquid crystal layer 21 is sandwiched between A and A, the color liquid crystal panel 20 shown in FIG. 2 is manufactured.
0, the orientation direction of the alignment film 65 is different in the portions corresponding to each color of the color filters R, G, and B, so the twist angles of the liquid crystal in those portions are different.

In addition to the manufacturing method described above, there is a manufacturing method in which the alignment direction of the alignment film 65 is made different in the portions corresponding to each color of the color filters R, G, and B by rubbing.

In this method, in the first step, an alignment film 65 is formed by a normal method instead of the oblique vapor deposition of SiO shown in FIG. 6(C), and then an alignment film 65 is formed as shown in FIG. Rubbing is performed in a predetermined direction. In the second and third steps, an alignment film 65 is formed by a normal method, and then rubbing is performed in directions different from the directions shown in FIG. 6(C).

In this way, in each step, by changing the rubbing direction for each color of the color filter 24 on the second substrate 20B, it is possible to change the twist angle of the liquid crystal layer 21 in the portion of the color filter 24 corresponding to each color. can.

FIG. 10 shows a color liquid crystal panel 30 according to another embodiment of the present invention.
FIG. In the color liquid crystal panel 30 of this embodiment, the liquid crystal layer 31 is formed on two substrates 3, a first and a second substrate.
It is enclosed between 0A and 30B. The first substrate 30A includes a glass substrate 35 and an ITO film serving as a scanning electrode.
33 and an alignment film 38.
are laminated in this order inside the glass substrate 36.

The second substrate 30B consists of a glass substrate 35, R, G, and B color filters 34, ITO 32 serving as data electrodes, and an alignment film 37. The color filter 34 is first provided on the glass substrate 35, and then Separate ITO layers 37 for each color of R, G, and B are laminated on the color filter 34, and an alignment film 37 is laminated thereon.

The first substrate 30A in this embodiment has exactly the same configuration as a conventional liquid crystal panel. On the other hand, the second group Fi
In 30B, the alignment film 27 is formed so that pretilt angles θ8, θ6, and θ8 of liquid crystal molecules are different at portions corresponding to color filters R, G, and B, respectively. The magnitude of this pretilt angle is θ8>θ. > Set it to θ8. The reason for this will be explained using FIG. 11.

FIG. 11 shows T-■ characteristics depending on the pretilt angle of green light. As can be seen from this figure, the larger the pretilt angle, the lower the threshold voltage of the TV characteristic.

Therefore, if the pretilt angle is the same, the pretilt angle is set small for blue (B), which has a low threshold voltage, and at the same pretilt angle, the pretilt angle is set large for red (R), which has a high threshold voltage. By doing so, the threshold voltages of each color of R, G, and B will be almost equal.

As explained above, the color liquid crystal panel 3 of this embodiment
In the case of 0, the threshold voltages of red, green, and blue are almost the same, so the amounts of transmitted light for each color are equal, and the black state does not have a bluish tinge.

The method of manufacturing a color liquid crystal panel by changing the pretilt angle corresponding to each color of the color filter 37 as described above is the same as the method explained in FIGS. 6, 7, and 9. That is, by performing the oblique vapor deposition of SiO, the SiO crystal molecules 37m adhere obliquely to the ITO 32, as shown in FIG. Therefore, the alignment film 27 can be formed so that the pretilt angles θ, θ6, and θ of the liquid crystal molecules are different at the portions corresponding to the color filters R1G and B, respectively. Furthermore, by changing the rubbing direction, the angle at which the fibrous member coming out of the alignment film 37 extends changes, as shown in FIG. 12(b), and the pretilt angle of the liquid crystal molecules 31m changes according to this angle. Therefore, the alignment film 27 can be formed so that the pretilt angles θ8, θ6, and θ of the liquid crystal molecules are different at the portions corresponding to the color filters R, G, and B, respectively.

〔Effect of the invention〕

As explained above, according to the present invention, the amount of transmitted light of each color on a color liquid crystal panel can be controlled more easily and more reliably, and the amount of transmitted light of each color is made almost constant, and the black state of the color liquid crystal panel is maintained. Since bluishness can be prevented, the color display quality of the color liquid crystal panel can be improved.

[Brief explanation of the drawing]

1(a) and 1(b) are diagrams explaining the principle of the color liquid crystal panel of the present invention, FIG. 2 is a sectional view showing the configuration of an embodiment of the color liquid crystal panel of the present invention, and FIG. FIG. 4 is an explanatory diagram showing the magnitude of the twist angle of blue light. FIG. 5 is a diagram showing the TV characteristics according to the twist angle of green light. Figures (a) to (e) are process diagrams showing the first step of the method of manufacturing a color liquid crystal panel of the present invention, and Figures 7(a) to (e) are process diagrams showing the first step of the method of manufacturing a color liquid crystal panel of the present invention FIG. 8 is an explanatory diagram showing the oblique vapor deposition method of SiO, FIG. 9 is a diagram showing another manufacturing method of the present invention, and FIG. 10 is a diagram showing another manufacturing method of the color liquid crystal panel of the present invention. 11 is a diagram showing the TV characteristics according to the pretilt angle of green light; FIGS. 12(a) and 12(b) are diagrams explaining the method of controlling the pretilt angle; FIG. 13 is a sectional view showing the structure of a conventional color liquid crystal panel, and FIG. 14 is a characteristic diagram showing TV characteristics of each color under the same conditions. 1.21.31...Liquid crystal layer, 2.3...Electrode, 4.24.34.63...Color filter, 5...
Polarity conversion circuit, 22.23.32.33.64...ITO125,2
6, 35, 36, 61... glass substrate, 27.28.
37.38.65...Alignment film, 62...Resist,

Claims (1)

[Claims] 1. A plurality of transparent electrodes (2
), (3), and performs color display using a color filter (4) of three colors R, G, and B, in which a portion corresponding to R and a portion corresponding to G of the color filter (4) are provided. A color liquid crystal panel characterized in that the twist angles of the liquid crystal in a portion corresponding to B and a portion corresponding to B are made different so that the amount of transmitted light of each color is equal. 2. A plurality of transparent electrodes (2) intersecting with the liquid crystal layer (1) in between
), (3), and performs color display using a color filter (4) of three colors R, G, and B, in which a portion corresponding to R and a portion corresponding to G of the color filter (4) are provided. A color liquid crystal panel characterized in that the pretilt angles of the liquid crystal in a portion corresponding to B and a portion corresponding to B are made different so that the amount of transmitted light of each color is equal. 3. A resist is applied to the liquid crystal layer side of one of the transparent insulating substrates sandwiching the liquid crystal layer, and this resist is peeled off by exposure to only a portion corresponding to a certain color, and a certain color is applied to the peeled portion and the remaining resist. Provide a filter by coating or printing,
a step of laminating an electrode thereon; and depositing SiO as an alignment film on the substrate in this state at an angle to the normal direction of the substrate and at a predetermined angle to a certain side of the substrate. step, and a laminate of resist, color filter, electrode, and alignment film layered on the substrate,
The first step consists of removing the SiO from the substrate, and the above steps are performed for the remaining two colors.
A method for manufacturing a color liquid crystal panel, comprising second and third steps in which the deposition angle with respect to the normal direction of the substrate is the same, and the deposition angle with respect to a certain side of the substrate is made different. 4. Applying a resist to the liquid crystal layer side of one of the transparent insulating substrates sandwiching the liquid crystal layer, and peeling off only the part corresponding to a certain color by exposing this resist, and applying a certain color to the peeled part and the remaining resist. Provide a filter by coating or printing,
a step of laminating an electrode thereon, a step of applying an alignment film on the substrate in this state, and a step of performing a rubbing treatment in an alignment direction corresponding to the certain color after coating; a step of laminating a resist and a color filter on the substrate; ,electrode,
The first step consists of removing the laminate of the alignment film and the alignment film from the substrate, and the second step consists of performing the above steps for each of the remaining two colors, and changing the rubbing direction for each color after applying the alignment film. 2
, a third step; and a method for manufacturing a color liquid crystal panel.