JPH01293303A - Color filter - Google Patents

Abstract

PURPOSE:To satisfy the color purity of the primary colors until they are visually inconspicuous and to set the center of gravity of the chromaticity coordinates of the primary colors closer to blue than to a white point by adjusting the spectral transmission characteristics of a color separating element into specific areas. CONSTITUTION:The spectral transmission characteristics of the color separating element are adjusted into ranges of 440nm<=lambda1B<=470nm, 50%<=T1B<=90%, 490 nm<=lambda2B<=520nm, 520nm<=lambda1G<=540nm, 50%<=T1G<=90%, 490nm<=lambda2G<=510nm, 570nm<=#89l2G<=590nm, 620nm<=lambda1R<=700nm, 70%T1R<=95%, and 580nm<=lambda2R<=600 nm. Here, lambda1 is the maximum transmissivity wavelength, T1 the maximum transmissivity, lambda2 the half-value wavelength of transmissivity; and B as subscripts of T1 and lambda2 indicates blue, G green, and R red. Consequently, the color purity of the respective primary colors is satisfied until they are visually inconspicuous and the centers of the chromaticity coordinates of the primary colors become close to blue than to the white point.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a color filter used in an image display device such as a color liquid crystal display device, a fluorescent display device, or a plasma display device.

(Conventional technology) Red and blue are generally used in image display devices.

The spectral transmittance characteristics of the color separation element that constitutes the green primary color color filter are as follows: ■The color purity of each of the three primary colors is high, and the chromaticity coordinates of each color are similar to the chromaticity coordinates of the standard phosphor of color television receivers. Close to.

■The brightness of each of the three primary colors is high.

In order to satisfy the following, the center of gravity of the chromaticity coordinates of the three primary colors was shifted from the white point toward the red direction.

(Problem to be Solved by the Invention) However, recently, there has been a tendency to prefer display devices whose centers of gravity of the chromaticity coordinates of the three primary colors are slightly shifted in the blue direction from the white point.

However, due to the nature of the pigment, the transmittance of the red pigment is the highest among the three primary colors, and the transmittance of the red pigment is 600 to 70.
Even if the color density is changed in the wavelength range of 0 nm (red), the transmittance hardly changes. On the other hand, blue pigments and green pigments have lower transmittance than red even at their respective maximum transmittance wavelengths, and their transmittances attenuate gently at wavelengths other than the maximum transmittance wavelengths. Adjusting the transmittance of a blue or green dye necessarily affects the transmittance of other color regions.

Specifically, if an attempt is made to increase the transmittance of blue and green to the same level as that of red, the transmittance of other color regions will increase, resulting in a decrease in color purity.

Therefore, in the conventional concept of color filters, there is a problem in that no matter how the dye composition is adjusted, it is extremely difficult to shift the center of gravity of the chromaticity coordinates of the three primary colors in the blue direction from the white point.

Therefore, the present invention was made in consideration of the above circumstances and in light of colorimetry, and it satisfies the color purity of each of the three primary colors to the extent that it is not visually noticeable, and the brightness of each of the three primary colors is high. The purpose of this invention is to provide a color filter in which the center of gravity of the chromaticity coordinates of the three primary colors is slightly closer to the blue direction than the white point.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides a color filter in which color separation elements of three primary colors of red (R), blue (B), and green (G) are arranged on the same substrate. This is a color filter characterized in that the spectral transmittance characteristics of the color filter are adjusted to fall within the range of the following characteristics.

4401R10≦λ1. ≦470 nm50%≦TIM
≦90% 490nm ≦ λ21R ≦ 5 2 On1l1
5200 mountains≦λ1゜≦540 nm 50%≦TIG≦90% 490nm≦λ. ≦510 nn m570n≦λ2゜≦5 9 0 71R1R620n
ffl≦λ, l≦7 0 Or+m70%≦T1. ≦
95% 580nm≦λ2R≦6001m However, λ1 is the maximum wavelength of transmittance, TI is the maximum value of transmittance, λ2 is the half-value wavelength of transmittance, and λ.

, T1 or λ2, the subscript B is blue, G
indicates green, and R indicates red.

Further, in the present invention, in the color filter, barycenter point coordinates (xe, ye) in an international standard chromaticity diagram obtained using an international standard C light source are 0.27≦xc≦0.3.
2 0.25≦yc≦0631.

(Function) The pigments of the color separation elements of the three primary colors constituting the color filter of the present invention are adjusted so that the transmittance maximum wavelength, transmittance maximum value, and transmittance half value wavelength for each of the three primary colors fall within a predetermined range. By adjusting, the color purity of each of the three primary colors is satisfied to the extent that it is not visually noticeable, and the brightness of each of the three primary colors is high, and the center of gravity of the chromaticity coordinates of the three primary colors is lower than the white point. It becomes a little closer to blue.

(Example) The present invention will be described in further detail with reference to embodiments.

Table 1 shows the spectral characteristics of the R, G, and B color separation elements of the color filter arranged on the same substrate of the present invention. The chromaticity coordinates of the three primary colors should be close to the standard phosphor chromaticity coordinates, and the brightness of each of the three primary colors should be high. The spectral characteristics of the R, G, and B color separation elements are adjusted in consideration of the following.

Table 1 As a result, as is clear from Table 1, the coordinates of the center of gravity are slightly shifted in the blue direction from the white point.

FIG. 1 shows the measurement results of the spectral transmittance characteristics of the R, G, and B color separation elements adjusted as shown in Table 1. According to the figure, the transmittance at the intersection of the green curve and the blue curve is higher than the transmittance at the intersection of the red curve and the green curve. Therefore, when the color separation element of this embodiment is used as a color filter, the actual white point will be slightly shifted in the blue direction from the true white point.

In a color liquid crystal display screen using a color filter adjusted in this way, we visually evaluated the display screen when all pixels corresponding to the R, G, and B color separation elements were turned on to display a white color. It was confirmed that the color was white with a bluish tinge.

(Comparative Example) Table 2 shows the spectral characteristics of RlG and B color separation elements of a color filter arranged on the same substrate based on the design concept of color separation elements constituting a conventional three-primary color filter.

Table 2 As a result, as is clear from Table 2, the coordinates of the center of gravity are slightly shifted in the red direction from the white point.

FIG. 2 shows the measurement results of the spectral transmittance characteristics of the R, G, and B color separation elements adjusted as shown in Table 2. According to the figure, when the color separation element of the comparative example is used as a color filter, the actual white point is slightly shifted in the red direction from the true white point.

When we visually evaluated the display screen using the color filter of the comparative example when all the pixels corresponding to the R, G, and B color separation elements were turned on to display white, we found that no reddishness was observed. It was confirmed that it had a tinged white color.

FIG. 3 is a CIE chromaticity diagram (international standard chromaticity diagram) shown to explain the difference in the center of gravity between the above embodiment of the present invention and the comparative example.

According to the figure, the center of gravity of the example of the present invention is located toward the blue side of the white area, while the center of gravity of the comparative example is located toward the red side of the white area. .

〔Effect of the invention〕

According to the present invention, the pigments of the color separation elements of the three primary colors constituting the color filter are arranged so that the transmittance maximum wavelength, transmittance maximum value, and transmittance half value wavelength for each of the three primary colors fall within a predetermined range. By making the adjustment, it is possible to obtain a color filter in which the color purity of each of the three primary colors is satisfied to the extent that it is not visually noticeable, and the center of gravity of the chromaticity coordinates of the three primary colors is slightly closer to the blue direction than the white point.

Therefore, when this color filter is used in a color liquid crystal display element, an excellent display quality with good color reproducibility and white balance can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a characteristic diagram showing the spectral transmittance characteristics of a color separation filter element according to an embodiment of the present invention, FIG. 2 is a characteristic diagram showing spectral transmittance characteristics of a conventional color separation filter element, and FIG. FIG. 2 is a CIB chromaticity diagram showing the coordinates of the center of gravity of color separation filter elements according to an embodiment of the present invention and a conventional color separation filter element. Wavelength (1 plane) Wavelength (nm) Figure 3

Claims (1)

[Scope of Claims] (1) A color filter in which color separation elements for the three primary colors of red, blue, and green are arranged on the same substrate, wherein the spectral transmittance characteristics of the color separation elements are adjusted to the following characteristics. A color filter characterized by: 440nm≦λ_1_B≦470nm 50%≦T_1_B≦90% 490nm≦λ_2_B≦520nm 520nm≦λ_1_G≦540nm 50%≦T_1_G≦90% 490nm≦λ_2_G≦510 nm 570nm≦λ_2_G≦590nm 620nm≦λ_1_R≦700nm 70%≦T_1_R≦95 % 580nm≦λ_2_R≦600nm However, λ_1 is the maximum wavelength of transmittance, T_1 is the maximum value of transmittance, λ_2 is the half-value wavelength of transmittance, and the subscript B written on λ_1, T_1 or λ_2 is blue, and G is blue. green,
R represents red. (2) In the color filter according to claim 1, the barycenter point coordinates (x_c, y_c) in the international standard chromaticity diagram obtained using the international standard C light source are 0.27≦x_c≦0.32 0.25≦ A color filter characterized by being adjusted to satisfy y_c≦0.31.