JPH07159770A - LCD panel - Google Patents

Abstract

(57) [Summary] [Object] It is an object of the present invention to provide a multi-gap type liquid crystal panel capable of improving not only chromaticity of display colors but also contrast. [Structure] First polarizing plate 20 on which backlight light is incident
A multi-gap color filter 22 including R, G, and B filters having different thicknesses is installed on the upper side, and a second polarizing plate 26 is installed in parallel so as to face the first polarizing plate 20. There is. First and second alignment films 24 and 2 between the multi-gap color filter 22 and the second polarizing plate 26.
A liquid crystal having a refractive index anisotropy Δn = 0.094 is filled in the gap 8 to form a multi-gap type liquid crystal layer 30. The thickness d of the liquid crystal layer 30 on each of the R, G, and B filters
R, dG, and dB are 5.6 μm, 5.0 μm, and
It is 4.8 μm. This is retardation Δn
・ When expressed by d, 0.53 μm, 0.47 μm,
It becomes 0.45 μm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal panel, and more particularly to a multi-gap type liquid crystal panel capable of displaying a color image by using three primary color filters of red, green and blue. 2. Description of the Related Art In recent years, liquid crystal panels have been thin and lightweight and have high display quality, and thus have been attracting attention as a display device replacing CRTs. The mainstream these days is the active matrix type, which has a high display quality. Further, as a display mode of the liquid crystal panel, a TN (twisted nematic) type having a high display quality is mainly used.

[0002]

2. Description of the Related Art Generally, a TN type liquid crystal panel is roughly divided into two display modes, NW (normally white) and NB (normally black). In the NW mode, two polarizing plates sandwiching the liquid crystal are made to cross each other,
This is a mode in which the transmittance is maximized when the applied voltage is low, the liquid crystal is twisted by 90 °, and the tilt is small. On the other hand, the NB mode is a mode in which two polarizing plates sandwiching a liquid crystal are parallel to each other so that the transmittance is minimized in the same state. In addition, when a sufficient voltage is applied to the liquid crystal, the liquid crystal tilts largely, so that the optical rotatory power is lost, and the transmittance becomes the minimum in the NW mode.
Maximum in B mode.

However, there is generally a phenomenon called wavelength dispersion, which deteriorates the display quality in both modes. This wavelength dispersion is a phenomenon in which the angle of rotation of the polarized light incident on the panel is slightly different depending on the wavelength when the polarized direction is rotated by 90 ° along the twist of the liquid crystal. This chromatic dispersion is a particular problem in the NB mode. Coloring due to wavelength dispersion in the dark state of NB mode is shown in FIG.
3 will be used for the explanation.

As shown in FIG. 13 (a), the incident light passes through the first polarizing plate 50, and R (red), G (green), B
The liquid crystal layer 5 passes through the color filter 52 made of (blue).
After passing through 4, it reaches the second polarizing plate 56. At this time, the polarization axis of the second polarizing plate 56 is parallel to the polarization axis of the first polarizing plate 50, and when the light passes through the liquid crystal layer 54, its plane of polarization is rotated by 90 °. Therefore, the light transmitted through the liquid crystal layer 54 is blocked by the second polarizing plate 56. Thus, the dark state of the NB mode is realized.

However, how the transmittance changes depending on the wavelength of each color with respect to the retardation Δn · d, which is the product of the refractive index anisotropy Δn of the liquid crystal and the thickness d of the liquid crystal layer, was calculated by a computer. When the result is shown in the graph of FIG. 14, the retardation Δn · d at which the transmittance of green light having the highest human visibility is the lowest is about 0.475, and the contrast is maximized at this time. Then, it can be seen that the blue light and the red light are slightly transmitted.

Therefore, when a panel is manufactured so that when light passes through the liquid crystal layer 54, it is rotated by 90 ° about green light, blue light is rotated by 90 ° or more, and red light is rotated by 90 °. Only rotates below ゜. Therefore, as shown in FIG. 13A, while the green light is blocked by the second polarizing plate 56, the leakage light of blue and red is generated, so that the contrast is lowered and the color is purple. Become. That is, in the NB mode, there is no condition for obtaining black even if the retardation Δn · d of the liquid crystal layer 54 is changed.

As a method for improving this problem, FIG.
As shown in (b), R of the color filter 52,
A multi-gap method has been considered in which the thickness of the liquid crystal layer 54 corresponding to G and B is increased in the order of R, G, and B. For example, the thicknesses of the liquid crystal layers 54 corresponding to R, G, and B of the color filter 52 are 5.4 μm and 4.8 μm, respectively.
m of 3.7 μm has been proposed (Japanese Patent Laid-Open Publication No. Sho 6).
0-15982). Thereby, in principle, coloring due to wavelength dispersion can be considerably eliminated.

[0008]

However, even in the above-mentioned conventional multi-gap type liquid crystal panel, the light transmitted through the R, G and B color filters of the backlight actually used is not a single wavelength, respectively. As shown in FIGS. 2 and 5, there is a problem that coloring occurs due to the difference in optical activity even among the steps of the liquid crystal layer 54 corresponding to each of R, G, and B because of a certain spread.

Although the chromaticity of the display color of the liquid crystal panel of the multi-gap system is very close to an achromatic color as compared with the panel without the multi-gap, the brightness in the dark state is very high and the color is not black. There was also a problem that it became bright black (grayish color) and the contrast was almost the same as in the case of a panel without multi-gap. Therefore, an object of the present invention is to provide a multi-gap type liquid crystal panel that can improve the chromaticity of display colors and the contrast.

[0010]

The present inventors have investigated the cause of low contrast in a conventional multi-gap type liquid crystal panel. As shown in the schematic view of the multi-gap type liquid crystal panel of FIG.
The backlight light L1 emitted from 0 is transmitted through the multi-gap color filter 12 including the R, G, and B dot filters having different thicknesses, and transmitted through the red color filter transmitted light TR and the green color filter transmitted light TG. , Blue color filter transmitted light TB. These color filter transmitted lights TR, TG and TB have thicknesses dR, dG and dB, respectively.
And passes through the liquid crystal layer 14 to become red dot transmitted light UR, green dot transmitted light UG, and blue dot transmitted light UB. Then, the unit light L2 composed of these dot transmitted lights UR, UG, UB is emitted.

Therefore, the display color of the liquid crystal panel is determined by the combination of the emission spectrum of the backlight 10, the transmission spectrum of the multi-gap color filter 12, and the transmission spectrum of the liquid crystal layer 14. Therefore, when determining the step condition of the multi-gap, it is necessary to consider all of these conditions. Now, the thicknesses dR, dG, and dB of the liquid crystal layer 14 corresponding to the R, G, and B pixels are respectively set to dR.
= 5.4 μm, dG = 4.8 μm, dB = 3.7 μm, and assuming that the backlight 10 has an emission spectrum shown in the graph of FIG. 2, R, G, and Transmitted light from each pixel of B,
That is, the transmitted light spectra of the dot transmitted light UR, UG, UB in FIG. 1 are as shown in the graph of FIG.

That is, the R pixel well suppresses the transmission of red light near the wavelength of 600 nm, but the leakage light at the wavelength of 710 nm is rather large. The G pixel also well suppresses the peak near the wavelength of 550 nm. However, the B pixel has a wavelength of 435
Although it suppresses the blue peak near nm very well,
The transmission of green light with a wavelength of 545 nm and blue-green light with a wavelength of about 490 nm is very large.

By the way, the human eye's perception of brightness varies depending on the wavelength even with equal energy light stimulation,
While the yellow-green light with a wavelength of 555 nm seems to be the brightest, it feels so dark that the wavelength deviates from it, and the wavelength is 380 nm.
The light below and the wavelength of 780 nm or more are not felt at all. For this reason, the transmission of green light that is most bright to the human eye, here, the blue light and the green light of wavelength 490 and wavelength 545 nm from the B pixel is very large, which increases the brightness in the dark state. This is considered to be the main cause of the decrease in contrast.

As described above, it was found that the display color and the contrast of the liquid crystal panel are greatly changed depending on the thickness dR, dG and dB of the liquid crystal layer 14 corresponding to the respective R, G and B pixels. Therefore, the present inventors have found a means for solving the above problems by variously changing the thicknesses dR, dG, and dB of the liquid crystal layer 14 corresponding to the R, G, and B pixels, respectively. .

That is, the above problem is in a multi-gap type liquid crystal panel having red, green and blue color filters, in which at least the liquid crystal layer on the red filter is thicker than the liquid crystal layer on the blue filter. , The retardation of the liquid crystal layer on the blue filter is 0.38 μm to 0.46 μm
It is achieved by a liquid crystal panel characterized by being m.

In the above liquid crystal panel, the thickness of the liquid crystal layer on the red filter is thicker than the thickness of the liquid crystal layer on the green filter, and the thickness of the liquid crystal layer on the green filter is on the blue filter. This is achieved by a liquid crystal panel characterized by being thicker than the thickness of the liquid crystal layer. In the above liquid crystal panel, it is achieved by a liquid crystal panel characterized in that the thickness of the liquid crystal layer on the red filter is equal to the thickness of the liquid crystal layer on the green filter.

The above liquid crystal panel is achieved by a liquid crystal panel characterized in that the thickness of the liquid crystal layer on the green filter is equal to the thickness of the liquid crystal layer on the blue filter. In the above liquid crystal panel, the liquid crystal panel is a normally black mode liquid crystal panel. In the above liquid crystal panel,
The liquid crystal panel is achieved in a normally white mode.

[0018]

According to the present invention, the conventional multi-gap type liquid crystal panel is designed such that the thickness of the liquid crystal layer is suppressed so as to suppress the transmission of the peak wavelengths of R, G and B lights. , G, and B are not monochromatic (single wavelength light) but have respective spreads, B
The thickness of the liquid crystal layer corresponding to the pixel is thicker than the conventional one, and the step condition is determined so that the retardation Δn · d is 0.38 μm to 0.46 μm.

As a result, in the NB mode, although the chromaticity of the display color is almost the same as that of the conventional one, the transmission of green light, which is most bright to the human eye, can be suppressed, so that the contrast is made larger than that of the conventional one. Can be improved.
Therefore, the display color and the contrast can be compatible with each other, and the contrast can be improved while maintaining the chromaticity of the display color in a good condition.

Further, in the NW mode which has been the mainstream of liquid crystal panels in the past, the panel transmittance can be greatly improved.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on illustrated embodiments. FIG. 4 shows N according to the first embodiment of the present invention.
It is a schematic sectional drawing which shows the liquid crystal panel of the multi-gap system of B mode. Backlight light having the spectral characteristics shown in the graph of FIG. 2 is incident on the first polarizing plate 20. A multi-gap color filter 22 composed of R, G, and B filters having different thicknesses is installed on the first polarizing plate 20, and the multi-gap color filter 22 shown in FIG. It has a transmission characteristic as shown in the graph. The first alignment film 24 is formed on the multi-gap color filter 22.
Is provided.

Further, a second polarizing plate 26 having a polarization axis parallel to the polarizing axis of the first polarizing plate 20 is installed facing the first polarizing plate 20. And this second polarizing plate 26
The second alignment film 28 is provided below. Also,
A liquid crystal having a refractive index anisotropy Δn = 0.094 (ZLI-4792 manufactured by Merck Ltd.) is filled in a gap between the first alignment film 24 and the second alignment film 28, and a liquid crystal of a multi-gap system is formed. The layer 30 is formed. And color filter 2
2, the thickness dR of the liquid crystal layer 30 on each of the R, G, and B filters
, DG and dB are dR = 5.6 μm and dG =
The present embodiment is characterized in that 5.0 μm and dB = 4.8 μm. If this is represented by retardation Δn · d, Δn · dR = 0.53 μm and Δn · dG, respectively.
= 0.47 μm, Δn · dB = 0.45 μm.

The NB mode multi-gap type liquid crystal panel according to this embodiment is manufactured by the same manufacturing method as that of a normal multi-gap type liquid crystal panel.
That is, for example, a red pigment-added resin is applied to the first polarizing plate 20 to a predetermined thickness, and then patterned into a predetermined shape by selective exposure and development to form an R having a predetermined thickness. To form a filter. Then, in the same procedure, a G filter and a B filter each having a predetermined thickness are sequentially formed by applying a resin added with a predetermined pigment, selectively exposing it, and developing it. By controlling the thickness of each R, G, B filter in this manner, the thickness dR, dG, dB of the liquid crystal layer 30 on each R, G, B filter is controlled.

When the present inventors made a prototype of the NB mode liquid crystal panel according to this embodiment, a contrast of 90 or more could be obtained. The above-mentioned conventional gap condition, that is, d
R = 5.4 μm, dG = 4.8 μm, dB = 3.7 μm
Compared with the case where the contrast is 50 or less, the brightness in the dark state is low and the contrast is remarkably high. This is B of the color filter 22.
Retardation Δn · d of the liquid crystal layer 30 on the filter
Is 0.45 μm, which suppresses the transmission of blue-green light near the wavelength of 490 nm. However, since the blue light near the wavelength of 435 nm is transmitted, the chromaticity of the display color is more bluish than in the case of the conventional gap condition.

As described above, according to this embodiment, in the NB mode multi-gap type liquid crystal panel, the retardation Δn · d of the liquid crystal layer 30 on each of the R, G, and B filters of the color filter 22 is set. 0.53 μm,
By setting 0.47 μm and 0.45 μm, wavelength 4
Since the transmission of blue-green light near 90 nm is suppressed, the brightness in the dark state can be lowered and the contrast can be remarkably improved.

Next, a NW mode liquid crystal panel according to a second embodiment of the present invention will be described with reference to FIG. FIG. 6 is a schematic sectional view showing a NW mode multi-gap type liquid crystal panel according to a second embodiment. The above-mentioned FIG.
The same components as those of the liquid crystal panel shown in FIG.

In this embodiment, instead of the second polarizing plate 26 in the first embodiment, a second polarizing plate 32 having a polarization axis perpendicular to the polarization axis of the first polarizing plate 20 is installed. The difference is the same as the case of the first embodiment except for the difference. Therefore, the thicknesses dR, dG and dB of the liquid crystal layer 30 on the R, G and B filters of the color filter 22 are dR = 5.6 μm and dG, respectively.
= 5.0 .mu.m and dB = 4.8 .mu.m. That is,
In the present embodiment, the multi-gap method, which has been conventionally used only in the NB mode, is applied to the NW mode under the above gap condition.

When the inventors of the present invention prototyped the NW mode liquid crystal panel according to this embodiment, the brightness in the bright state was increased, the panel transmittance was improved by 10% or more, and the contrast was not the multi-gap type. When it was 100, it was improved to 110. This is because the retardation Δn · d of the liquid crystal layer 30 on the B filter of the color filter 22 is set to 0.45 μm. This is because light can now be transmitted well. Also, the chromaticity in the dark state was almost achromatic.

As described above, according to this embodiment, in the NW mode multi-gap type liquid crystal panel, the retardation Δn · d of the liquid crystal layer 30 on each of the R, G, and B filters of the color filter 22 is set. 0.53 μm,
By setting 0.47 μm and 0.45 μm, wavelength 4
Since blue-green light near 90 nm is well transmitted, the brightness in the bright state can be increased to improve the panel transmittance, and also the contrast can be improved. In addition, the chromaticity in the dark state can be almost achromatic. Therefore, it is possible to realize a panel having high transmittance, high contrast, and very excellent display color.

For example, the NW mode liquid crystal panel according to this embodiment is considered to be very effective for a notebook computer. Laptop computers need to reduce power consumption as much as possible because they are battery-operated, and the panel transmittance is 1
0% improvement means that the backlight brightness is 10%
This is because it means that the same image quality as the conventional one can be obtained even if the image is darkened.

Next, an NB mode liquid crystal panel according to the third embodiment of the present invention will be described with reference to FIG. FIG. 7 is a schematic sectional view showing an NB mode multi-gap type liquid crystal panel according to a third embodiment. The above-mentioned FIG.
The same components as those of the liquid crystal panel shown in FIG.

This embodiment is basically the same as the structure in the first embodiment, except that the thicknesses dR and d of the liquid crystal layer 30 on the R, G and B filters of the color filter 22 are the same.
G and dB are dR = 5.0 μm and dG = 5.0 μm, respectively
The only difference is that m and dB = 4.8 μm. That is, this embodiment is characterized in that the thicknesses dR and dG of the liquid crystal layer 30 on the R and G filters of the color filter 22 are made equal.

When the present inventors made a prototype of the NB mode liquid crystal panel according to this embodiment, the red light around the wavelength of 600 nm is slightly transmitted, and the chromaticity of the display color is better than that of the liquid crystal panel having no step. However, the contrast was improved to 60 or more. Further, since the thickness dR and dG of the liquid crystal layer 30 on each of the R and G filters are made equal, the step provided on the color filter 22 can be improved by one step, and therefore the manufacturing was very easy.

As described above, according to this embodiment, in the NW mode multi-gap type liquid crystal panel, the retardation Δn · d of the liquid crystal layer 30 on each of the R, G, and B filters of the color filter 22 is set. 0.47 μm,
By setting 0.47 μm and 0.45 μm, wavelength 4
Since the transmission of blue-green light near 90 nm is suppressed, the same effect as in the case of the first embodiment can be obtained, and the number of steps provided in the color filter 22 is reduced, so that the manufacturing is very easy. This makes it easier to reduce manufacturing unevenness.

Next, a liquid crystal panel according to a fourth embodiment of the present invention will be described with reference to FIG. FIG. 8 is a schematic sectional view showing a NW mode multi-gap type liquid crystal panel according to a third embodiment. The same components as those of the liquid crystal panel shown in FIG. 6 are designated by the same reference numerals and the description thereof will be omitted.

This embodiment is basically the same as the structure of the second embodiment, except that the thicknesses dR and d of the liquid crystal layer 30 on the R, G and B filters of the color filter 22 are the same.
G and dB are dR = 5.0 μm and dG = 5.0 μm, respectively
The only difference is that m and dB = 4.8 μm. That is, this embodiment is characterized in that the thicknesses dR and dG of the liquid crystal layer 30 on the R and G filters of the color filter 22 are made equal.

When the present inventors made a prototype of the NW mode liquid crystal panel according to this embodiment, the red transmitted light around the wavelength of 600 nm was slightly reduced, and the improvement of the transmittance was about 5%. The chromaticity in the dark state was almost achromatic. Further, the thickness dR, d of the liquid crystal layer 30 on each of the R and G filters is
By setting G to be equal, the step provided on the color filter 22 can be improved by one step, so that the manufacturing was very easy.

As described above, according to the present embodiment, in the NW mode multi-gap type liquid crystal panel, the retardation Δn · d of the liquid crystal layer 30 on each of the R, G and B filters of the color filter 22 is respectively set. 0.47 μm,
By setting 0.47 μm and 0.45 μm, wavelength 4
Since blue-green light near 90 nm is well transmitted,
It is possible to obtain the same effects as in the case of the embodiment described above, and since the number of steps provided in the color filter 22 is reduced, manufacturing is very easy and manufacturing unevenness can be reduced.

Next, a liquid crystal panel according to a fifth embodiment of the present invention will be described with reference to FIG. FIG. 9 is a schematic sectional view showing an NB mode multi-gap type liquid crystal panel according to a fifth embodiment. The same components as those of the liquid crystal panel shown in FIG. 4 are designated by the same reference numerals, and the description thereof will be omitted.

This embodiment is basically the same as the structure in the first embodiment, except that the thicknesses dR and d of the liquid crystal layer 30 on the R, G and B filters of the color filter 22 are the same.
G and dB are dR = 5.6 µm and dG = 5.0 µm, respectively.
The only difference is that m and dB = 5.0 μm. That is, this embodiment is characterized in that the thicknesses dG and dB of the liquid crystal layer 30 on the G and B filters of the color filter 22 are made equal.

When the present inventors made a prototype of the NB mode liquid crystal panel according to this embodiment, almost the same results as in the case of the third embodiment were obtained. However, the third embodiment is different in that the red light around the wavelength of 600 nm is slightly transmitted, whereas the blue light around the wavelength of 435 nm is slightly transmitted in the present embodiment. As described above, according to this embodiment, in the NW mode multi-gap type liquid crystal panel, the retardation Δn · d of the liquid crystal layer 30 on each of the R, G and B filters of the color filter 22 is 0.53 μm. , 0.47 μm, and 0.47 μm, the effect is slightly insufficient, but the same effect as the case of the first embodiment can be obtained, and the same as the case of the third embodiment. In addition, manufacturing becomes extremely easy, and manufacturing unevenness can be reduced.

Next, a liquid crystal panel according to a sixth embodiment of the present invention will be described with reference to FIG. FIG. 10 shows the third
FIG. 3 is a schematic cross-sectional view showing a NW mode multi-gap type liquid crystal panel according to the example of FIG. The same components as those of the liquid crystal panel shown in FIG. 6 are designated by the same reference numerals and the description thereof will be omitted.

This embodiment is basically the same as the structure of the second embodiment, except that the thicknesses dR and d of the liquid crystal layer 30 on the R, G and B filters of the color filter 22 are the same.
G and dB are dR = 5.6 µm and dG = 5.0 µm, respectively.
The only difference is that m and dB = 5.0 μm. That is, this embodiment is characterized in that the thicknesses dG and dB of the liquid crystal layer 30 on the G and B filters of the color filter 22 are made equal.

When the inventors of the present invention prototyped the NW mode liquid crystal panel according to the present embodiment, almost the same results as in the case of the fourth embodiment were obtained. However, in the fourth embodiment, the red transmitted light around the wavelength of 600 nm is slightly reduced, whereas the present embodiment is different in that the blue transmitted light around the wavelength of 435 nm is slightly reduced. As described above, according to this embodiment, in the NW mode multi-gap type liquid crystal panel, the retardation Δn · d of the liquid crystal layer 30 on each of the R, G and B filters of the color filter 22 is 0.53 μm. , 0.47 μm, and 0.47 μm, blue-green light around a wavelength of 490 nm is well transmitted, so that the effect is somewhat insufficient, but the same effect as in the case of the second embodiment can be obtained. In addition to the above, the manufacturing becomes very easy as in the case of the fourth embodiment, and the manufacturing unevenness can be reduced.

Next, a liquid crystal panel according to a seventh embodiment of the present invention will be described with reference to FIG. FIG. 11 is the seventh
FIG. 3 is a schematic cross-sectional view showing an NB mode multi-gap type liquid crystal panel according to the example of FIG. The same components as those of the liquid crystal panel shown in FIG. 4 are designated by the same reference numerals, and the description thereof will be omitted.

This embodiment is basically the same as the structure in the first embodiment, except that the thicknesses dR and d of the liquid crystal layer 30 on the R, G and B filters of the color filter 22 are the same.
G and dB are dR = 5.6 µm and dG = 5.0 µm, respectively.
The only difference is that m and dB = 4.2 μm. That is, the liquid crystal layer 30 on the B filter of the color filter 22
The thickness dB of the above is an intermediate value between the conventional condition that the chromaticity of the display color is good, that is, dB = 3.7 μm, and the condition of the first embodiment that the contrast is good, that is, dB = 4.8 μm. The feature of this embodiment lies in that.

When the inventors of the present invention made a prototype of the NB mode liquid crystal panel according to this embodiment, the blue light near the wavelength of 435 nm and the blue-green light near the wavelength of 490 nm are slightly transmitted, but the chromaticity in the dark state is considerably high. It was close to achromatic and had a contrast of 80. In this case, the chromaticity in the dark state is almost equal to that in the conventional multi-gap system, and the contrast is improved to 1.6 times.

The transmitted light spectrum from the B pixel at this time is shown in the graph of FIG.
For comparison, the spectrum of transmitted light from the B pixel in the case of the above-described conventional gap condition is shown by a broken line in the graph. From this graph, the transmission of blue light near the wavelength of 435 nm is slightly larger than that under the conventional condition,
It can be seen that the transmission of the blue-green light near m and the green light near the wavelength of 545 nm is significantly suppressed as compared with the case of the conventional condition. Therefore, the thickness dB of the liquid crystal layer 30 on the B filter is
It was confirmed that there is a condition that the chromaticity of the display color and the contrast are compatible with each other by making the thickness thicker than the conventional one.

As described above, according to this embodiment, in the NB mode multi-gap type liquid crystal panel, the retardation Δn · d of the liquid crystal layer 30 on each of the R, G and B filters of the color filter 22 is respectively set. 0.53 μm,
By setting the thickness to 0.47 μm and 0.39 μm, the contrast can be improved while maintaining the chromaticity of the display color in a good condition.

In the first, third, fifth and seventh embodiments, the thicknesses dR, dG and dB of the liquid crystal layer 30 on the R, G and B filters of the color filter 22 are respectively set. Although it is set to a predetermined value, it goes without saying that the value is not limited to these values. Generally, when the chromaticity of the display color of the liquid crystal panel is emphasized, the contrast is lowered, and when the emphasis is placed on the contrast, the chromaticity tends to be deteriorated. Therefore, the retardation of the liquid crystal layer on the B filter is 0.38 μm.
Within the range of .about.0.46 .mu.m, the thickness dR, d of the liquid crystal layer 30 on each of the R, G, and B filters depends on how much importance is placed on chromaticity and contrast, and the intended use.
It is desirable to control G and dB respectively.

[0051]

As described above, according to the present invention, red, green,
In a multi-gap type liquid crystal panel that has a blue color filter and at least the thickness of the liquid crystal layer on the red filter is greater than the thickness of the liquid crystal layer on the blue filter, the retardation of the liquid crystal layer on the blue filter is , 0.38 μm to 0.46 μm, in the NB mode, it is possible to suppress the transmission of green light, which is the brightest to the human eye, so that the chromaticity of the display color is kept good. , It is possible to significantly improve the contrast.
In the case of NW mode, on the contrary, the green light is well transmitted, so that the panel transmittance can be improved. Therefore, NB is a method that is expected to make further progress in the future.
It can make a great contribution to the promotion of the mode,
Further, the NW mode, which has been the mainstream of liquid crystal panels in the past, can be very effectively utilized especially in the field where low power consumption is required by improving the panel transmittance.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a multi-gap type liquid crystal panel.

FIG. 2 is a graph showing an emission spectrum of a backlight.

FIG. 3 is a diagram illustrating a dot-transmitted light UR, UG, from each pixel of R, G, and B in a conventional multi-gap type liquid crystal panel.
It is a graph which shows the transmitted light spectrum of UB.

FIG. 4 is a schematic cross-sectional view showing an NB mode multi-gap type liquid crystal panel according to a first embodiment of the present invention.

FIG. 5 is a graph showing transmission characteristics of a color filter including R, G, and B filters.

FIG. 6 is a schematic cross-sectional view showing a NW mode multi-gap type liquid crystal panel according to a second embodiment of the present invention.

FIG. 7 is a schematic cross-sectional view showing an NB mode multi-gap type liquid crystal panel according to a third embodiment of the present invention.

FIG. 8 is a schematic cross-sectional view showing a NW mode multi-gap type liquid crystal panel according to a fourth embodiment of the present invention.

FIG. 9 is a schematic cross-sectional view showing an NB mode multi-gap type liquid crystal panel according to a fifth embodiment of the present invention.

FIG. 10 is a schematic cross-sectional view showing a NW mode multi-gap type liquid crystal panel according to a sixth embodiment of the present invention.

FIG. 11 is a schematic cross-sectional view showing an NB mode multi-gap type liquid crystal panel according to a seventh embodiment of the present invention.

12 is a graph showing a transmitted light spectrum from a B pixel in the liquid crystal panel shown in FIG.

FIG. 13 is a schematic diagram for explaining the conventional coloring by wavelength dispersion in the dark state of the NB mode and elimination of coloring by the multi-gap method.

FIG. 14 is a graph showing changes in transmittance depending on the wavelength of each color with respect to retardation Δn · d of liquid crystal.

[Explanation of symbols]

 10 ... Backlight 12 ... Multigap color filter 14 ... Liquid crystal layer 20 ... First polarizing plate 22 ... Multigap color filter 24 ... First alignment film 26 ... Second polarizing plate 28 ... Second alignment film 30 ... Liquid crystal layer 32 ... Second polarizing plate L1 ... Backlight light TR ... Red color filter transmitted light TG ... Green color filter transmitted light TB ... Blue color filter transmitted light dR, dG, dB ... Liquid crystal layer thickness UR ... Red dot transmitted light UG ... Green dot transmitted light UB ... Blue dot transmitted light L2 ... Unit light 50 ... First polarizing plate 52 ... Color filter 54 ... Liquid crystal layer 56 ... Second polarizing plate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kunihiro Tashiro 1015 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited (72) Inventor Tadashi Hasegawa, 1015, Kamedotachu, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited

Claims (6)

[Claims] 1. A multi-gap type liquid crystal panel having red, green and blue color filters, wherein the liquid crystal layer on the red filter is thicker than the liquid crystal layer on the blue filter. The retardation of the upper liquid crystal layer is 0.3
A liquid crystal panel having a thickness of 8 μm to 0.46 μm. 2. The liquid crystal panel according to claim 1, wherein the thickness of the liquid crystal layer on the red filter is larger than the thickness of the liquid crystal layer on the green filter, and the thickness of the liquid crystal layer on the green filter is A liquid crystal panel characterized by being thicker than the thickness of the liquid crystal layer on the blue filter. 3. The liquid crystal panel according to claim 1, wherein the thickness of the liquid crystal layer on the red filter is equal to the thickness of the liquid crystal layer on the green filter. 4. The liquid crystal panel according to claim 1, wherein the thickness of the liquid crystal layer on the green filter is equal to the thickness of the liquid crystal layer on the blue filter. 5. The liquid crystal panel according to claim 1, wherein the liquid crystal panel is a normally black mode. 6. The liquid crystal panel according to any one of claims 1 to 4, wherein the liquid crystal panel is a normally white mode.