JPS6169091A - Matrix type liquid crystal color display - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a matrix type liquid crystal color display device using color filters.

(Structure of Conventional Example and its Problems) Hereinafter, a conventional matrix type liquid crystal color display device will be described with reference to the drawings.

FIG. 1 is a plan view schematically showing the configuration of a conventional matrix type liquid crystal color display device, and FIG. 2 is an A-A in FIG.
FIG. 1 is the front board.

2 is a back substrate, 3 is a transparent electrode provided on the front substrate, 4 is a transparent electrode provided on the back substrate 2 facing the transparent electrode 3, 5 is a color filter, and 6 is the front side. A polarizing plate, 7 is a back polarizing plate, 8 is a sealing member, and 9 is a liquid crystal layer. FIG. 3 is a plan view showing a conventional example of a mosaic filter arrangement, and FIG. 4 is a plan view showing a conventional example of a striped filter arrangement. -B indicates red, green, and blue filters, respectively.

A conventional matrix type liquid crystal color display device configured as described above will be explained. Light is input from the back side of the device, and the light is converted into linearly polarized light by the back side polarizing plate 7.

Provided on the front substrate 1 and the rear substrate 2, facing each other,
By applying a voltage between the transparent electrodes 3 and 4, the alignment state of liquid crystal molecules in the liquid crystal layer 9 changes, and the polarization state of light passing through the liquid crystal layer 9 changes. The above light is analyzed by the front flange polarizing plate 6, and the amount of transmitted light is changed. At this time.

Color display is performed when light passes through a color filter 5 placed on the optical path, and a filter of a different color is used for each minute pixel in close proximity, and the color mixing effect of the transmitted light is used to create a filter. Full-color display is achieved by displaying colors other than color and white.

In general, in negative-tone LCD panels using twisted nematics when color filters are not used,
The light transmittance of white light is not constant with respect to wavelength, but is
As an example is shown in the figure, the light transmittance on the short wavelength side is smaller than the light transmittance on the long wavelength side.

Therefore, in a negative liquid crystal display device using color filters and twisted nematics in the conventional configuration, the amount of transmitted light from green to red is greater than the amount of transmitted light of blue, so the reproducibility of one color is limited by the xy chromaticity coordinates. As an example, as shown in Fig. 6, even if the color mixing effect of red, green, and blue shown by R-G-B is used, the color will be biased towards the red side, and the white point W will also be CIE shown by the Δ mark. It has the disadvantage of being on the greenish-red side of the color of the standard light Dls of daylight. This significantly degrades the display quality of a full-color display device.

(Object of the Invention) An object of the present invention is to provide a matrix-type liquid crystal color display device for full-color display that has a wide one-color reproduction range and has good white display quality.

(Structure of the Invention) The structure of the matrix type liquid crystal color display device according to the present invention is as follows: - In the matrix type liquid crystal color display device equipped with color filters of at least three colors, the area of the filter is different for each color. This structure improves the color reproduction range and white point of the display, and enables good full-color display.

(Description of Examples) Examples of the present invention will be described below with reference to the drawings.

FIG. 7 shows an embodiment of the filter arrangement of a matrix type liquid crystal color display device according to the present invention.

In FIG. 7, R represents a red filter, G represents a green filter, and B represents a blue filter. In this example, the area of the green filter is equal to the area of the red filter, and the area of the blue filter is twice the area of the red filter.
This is an example in which the number is doubled.

A matrix type liquid crystal color display device according to an embodiment of the present invention constructed as shown in FIG. 7 will be described. A white fluorescent lamp having the spectral distribution shown in FIG. 8 is used as a light source, and a voltage is applied between the opposing transparent electrodes 9 and 10 of the matrix type liquid crystal color display device. The color reproduction range and the xy chromaticity coordinates of the white point of the matrix type liquid crystal color display device according to the present invention in this case are shown in FIG. 9 together with the conventional example. In FIG. 9, R-G・B
-W indicates red, green, blue, and white, respectively, O mark indicates an embodiment according to the present invention, 10 mark indicates a conventional example, Δ mark indicates CIE daylight standard luminance, and the chromaticity coordinates of In the embodiment according to the present invention, the reproduction range of one color is expanded compared to the conventional example, the reproducibility of blue is good, and the chromaticity coordinate of white is close to that of standard light (color of D6). It can be seen that the whiteness is also improved.

As described above, according to this embodiment, in a matrix type liquid crystal color display device equipped with a color filter, the area of the filter is configured to be different for each color, thereby improving the color reproduction range and white point. Improvements have been realized.

Furthermore, in order to further clarify the effects of the present invention, other embodiments according to the present invention will be described with reference to figures.

When the filter arrangement shown in Fig. 7 is applied to a matrix type liquid crystal color display device, the area of the green filter is 0.8 times, 1 time, and 1.25 times the area of the red filter, and the area of the blue filter is 0.8 times, 1 time, and 1.25 times the area of the red filter. Examples will be described in which the area is 1.2 times, 1.5 times, 2 times, 2.5 times, and 3 times the area of the red filter. A white fluorescent lamp having the spectral distribution shown in No. 8@ is used as a light source, and a voltage is applied between the opposing transparent electrodes 3 and 4 of the matrix type liquid crystal color display device. Table 1 shows the xy chromaticity coordinates of red, green, blue, and white in this example together with the conventional example. As is clear from Table 1, in each of the embodiments of the present invention, the color reproduction range is wider than in the conventional example, the blue reproducibility is good, and the chromaticity coordinates of the white point are the CIE daylight standard. The light O@S
Chromaticity coordinate x=0.3127. y: approaching 0.3290.

As described above, according to the embodiment of the present invention, in a matrix type liquid crystal color display device equipped with a color filter, the area of the filter is configured to be different for each color, thereby improving single color reproducibility. The white point has been improved.

Next, in order to further clarify the effects of the present invention, other embodiments will be described with reference to charts.

In the matrix type liquid crystal color display device having the filter arrangement shown in FIG. 7, the area of the green filter is 0.8 times, 1 time, and 1.25 times the area of the red filter, and the area of the blue filter is is 1.2 times, 1.5 times, 2 times, 2.5 times, 3 times the area of the red filter
An example in which the number is twice as large will be described. As a light source, a CIE daytime standard light source Di having the spectrum shown in Fig. 9 is used.
sk, a voltage is applied between the opposing transparent electrodes 3 and 4 of the above matrix type liquid crystal color display device. The second table is
The xy chromaticity coordinates of the embodiment according to the present invention are shown together with the conventional example. Also in the embodiment of the shift according to the present invention, compared to the conventional example, the color reproduction range is widened, the reproducibility of blue color is good, and the chromaticity coordinate of the white point is CUE, which is equivalent to m of daylight. The chromaticity coordinate of X=0.3127. y=0.3
It's approaching 290.

As described above, according to this embodiment, in a matrix type liquid crystal display device equipped with a color filter, the area of the filter is configured to be different depending on the filter color, thereby improving the color reproduction range and white point. Improvements have been realized.

In the above embodiment, the filters were arranged in a mosaic arrangement as shown in FIG. The effects of the present invention can be obtained with any shape as long as it has the function of performing. For example, similar effects can be obtained by making the area of the filter different for each color in the striped arrangement shown in FIG. 11 or in other predetermined geometric shapes.

Furthermore, in the above embodiments, the light sources were a white fluorescent lamp having the spectral spectrum shown in FIG. 8 and an aSS light source having the spectral spectrum shown in FIG. The same effect can be obtained using a white light source having one or both of the two spectrums.

In addition, in the above example, the color of the filter is red, green,
Although the three colors of blue are used, the filter colors are not limited to red, green, and blue, but can be a combination of at least three types of filters that can display full colors, including white, through color mixing effects. For example, a combination of cyan, magenta, and yellow filters can be used.

(Effects of the Invention) As is clear from the above embodiments, the present invention employs a structure in which the area of the filter is different for each color in a matrix type liquid crystal display device equipped with color filters of at least three colors. This compensates for the wavelength distribution of the light transmittance of the liquid crystal layer, widening the color reproduction range.
This provides excellent blue reproducibility and a white point close to that of a standard light source. The effect of improving visibility in a full-color display device is very useful, and has great industrial value.

[Brief explanation of drawings]

Fig. 1 is a plan view of a matrix type liquid crystal color display device, Fig. 2 is a sectional view taken along line A-A in Fig. 1, Fig. 3 is a plan view of a conventional example of a mosaic filter arrangement, and Fig. 4 is a plan view of a matrix type liquid crystal color display device. A plan view of a conventional example of a striped filter array, Figure 5 is an example of the white light transmittance of a negative type liquid crystal display panel using twisted nematic, and Figure 6 is a matrix type liquid crystal color display device with a conventional configuration. FIG. 7 is a plan view of a mosaic filter array according to an embodiment of the present invention, and FIG. 8 is a spectral distribution of a light source used in an embodiment of the present invention. FIG. 9 is an xy chromaticity coordinate diagram according to an embodiment of the present invention, and FIG. 10 is a spectral distribution of CIE standard midday light. FIG. 11 is a plan view of a striped filter array according to an embodiment of the present invention. 1...Front side board, 2...Back side board, 3...
- Transparent electrode on the front substrate, 4... Transparent electrode on the back substrate, 5... Color filter, 6... Front polarizing plate, 7... Back polarizing plate, 8... Seal member, 9. ...Liquid crystal layer. Patent applicant Matsushita Electric Industrial Co., Ltd. Figure 1 Figure 2 et al Figure 5 Figure 5 Radiation (nm) Figure 6 (,30, + 0.2 0.3 0.4 0
．． 5 0.6 0.7 Figure 7 Figure 8 Figure 9 Figure 10 400 500, 600
700 800 liquid length + nm) Figure 11

Claims (5)

[Claims] (1) A matrix type liquid crystal display device comprising color filters for at least three colors, characterized in that the area of the filter is different for each color. (2) A matrix type liquid crystal color display device according to claim (1), wherein the color filters are arranged in a mosaic pattern. (3) A matrix type liquid crystal color display device according to claim (1), wherein the color filters are arranged in a stripe pattern. (4) A matrix type liquid crystal color display device according to claim (1), wherein the color filters are arranged in a predetermined geometric shape. (5) The area ratio of the three color filters of red, green, and blue is such that the area of the green filter is 0.8 to 1.25 times the area of the red filter, and
The matrix type liquid crystal color display device according to claim 1, wherein the area of the blue filter is 1.2 to 3 times as large as the area of the red filter.