US 7,248,313 B2Granted

Color filter and liquid crystal display device using the same

AssigneeSharp Kabushiki Kaisha

InventorsMasae Kitayama, Koji Matsuoka, Yukio Yoshida, Tsuyoshi Tokuda, Toshihide Tsubata

Life of this patent

Estimating the term…

Loading patent…

Abstract

A color filter of the present invention includes a large number of colored layers of a plurality of colors regularly arranged together. The color filter is such that xWH−0.05≦xB≦xWH+0.05 and yWH−0.05≦yB≦yWH+0.05 or xWH−0.10≦xB≦xWH and yWH−0.10≦yB≦yWH is satisfied, where (xWH, yWH) is the chromaticity in the CIE 1931 chromaticity diagram when the filter alone is irradiated with light to produce a white display, and (xB, yB) is the chromaticity in the CIE 1931 chromaticity diagram when the filter is irradiated with the same light while being interposed between a pair of polarization plates arranged in a crossed Nicols state each having a degree of polarization of 99.98% or more.

Claims8

Dependent claims

A color filter including colored layers of a number n of colors regularly arranged together, wherein:

1
2
×
Y
max
Y
max
′
≦
Y
min
Y
min
′
is satisfied, where Yi (i=1 to n) is a luminance of the colored layers of the n colors when the filter alone is irradiated with light, Yi′ (i=1 to n) is a luminance of the colored layers of the n colors when the filter is irradiated with the same light while being interposed between a pair of polarization plates arranged in a crossed Nicols state each having a degree of polarization of 99.98% or more, Ymax/Ymax′ is a maximum value of Yi/Yi′, and Ymin/Ymin′ is a minimum value of Yi/Yi′, and
Y
WH
Y
B
≧
4000
is satisfied, where YWH is a luminance when the filter alone is irradiated with light to produce a white display, and YB is a luminance when the filter is irradiated with the same light while being interposed between a pair of polarization plates arranged in a crossed Nicols state each having a degree of polarization of 99.98% or more and a transmittance of 36% when arranged in a parallel position.

19 more elements

A liquid crystal display device, comprising:

a liquid crystal cell including a first substrate, a second substrate provided so as to oppose the first substrate, and a liquid crystal layer provided between the first and second substrates, wherein a color filter including colored layers of a number n of colors regularly arranged together is provided on the first substrate;
and
a pair of polarization plates arranged in a crossed Nicols state and provided so as to interpose the liquid crystal cell therebetween, wherein:
the color filter is such that
1
2
×
Y
max
Y
max
′
≦
Y
min
Y
min
′
is satisfied, where Yi (i=1 to n) is a luminance of the colored layers of the n colors when the filter alone is irradiated with light, Yi′ (i=1 to n) is a luminance of the colored layers of the n colors when the filter is irradiated with the same light while being interposed between a pair of polarization plates arranged in a crossed Nicols state each having a degree of polarization of 99.98% or more, Ymax/Ymax′ is a maximum value of Yi/Yi′, and Ymin/Ymin′ is a minimum value of Yi/Yi′, and
Y
WH
Y
B
≧
4000
is satisfied, where YWH is a luminance when the filter alone is irradiated with light to produce a white display, and YB is a luminance when the filter is irradiated with the same light while being interposed between a pair of polarization plates arranged in a crossed Nicols state each having a degree of polarization of 99.98% or more and a transmittance of 36% when arranged in a parallel position.

23 more elements

A liquid crystal display device, comprising:

a liquid crystal cell including a first substrate, a second substrate provided so as to oppose the first substrate, and a liquid crystal layer provided between the first and second substrates, wherein a color filter including a large number of colored layers of red, green and blue regularly arranged together is provided on the first substrate;
and
a pair of polarization plates arranged in a crossed Nicols state and provided so as to interpose the liquid crystal cell therebetween, wherein:
the color filter is such that
1
2
×
T
G
T
G
′
≦
T
R
T
R
′
≦
2
×
T
G
T
G
′
and
1
2
×
T
B
T
B
′
≦
T
G
T
G
′
≦
2
×
T
B
T
B
′
and
1
2
×
T
R
T
R
′
≦
T
B
T
B
′
≦
2
×
T
R
T
R
′
is satisfied, where TR, TG and TB are transmittance values of the red, green and blue colored layers, respectively, when the filter alone is irradiated with light, and TR′, TG′ and TB′ are transmittance values of the red, green and blue colored layers, respectively, when the filter is irradiated with the same light while being interposed between a pair of polarization plates arranged in a crossed Nicols state each having a degree of polarization of 99.98% or more, and
Y
WH
Y
B
≧
4000
is satisfied, where YWH is a luminance when the filter alone is irradiated with light to produce a white display, and YB is a luminance when the filter is irradiated with the same light while being interposed between a pair of polarization plates arranged in a crossed Nicols state each having a degree of polarization of 99.98% or more and a transmittance of 36% when arranged in a parallel position.

77 more elements

Dependencies are inferred from the claim text.