External light shielding film and display filter having the same
View Patent ↗An external light shielding film including a lens pattern formed on a surface of a base substrate and including a plurality of aspheric lenses, and an external light shielding pattern formed on another surface of the base substrate, and a display filter having the same, are provided. The external light shielding film and the display filter having the same may increase a contrast ratio in a bright room, enhance brightness, and increase a viewing angle.
1. An external light shielding film comprising:
a lens pattern formed on a surface of a base substrate and including a plurality of aspheric lenses; and
an external light shielding pattern formed on another surface of the base substrate,
wherein an aspheric surface (Z) of each of the plurality of aspheric lenses is obtained by
z
(
r
)
=
Cr
2
1
+
1
-
(
1
+
k
)
C
2
r
2
+
Ar
4
+
Br
6
+
Cr
8
+
Dr
10
,
where ‘r’ denotes a radius of a spherical surface, ‘C’ denotes a spherical coefficient, ‘k’ denotes a conic constant, and ‘A’, ‘B’, ‘C’, and ‘D’ denote an integer of 2 through 7, respectively.
2. The external light shielding film of claim 1 , wherein the external light shielding pattern includes a plurality of external light shielding parts.
3. The external light shielding film of claim 2 , wherein a ratio of a number of the plurality of aspheric lenses to a number of the plurality of external light shielding parts is about 1:1 through about 1:4.
4. The external light shielding film of claim 2 , wherein each of the plurality of external light shielding parts is formed of an inclined surface defining a groove formed into the base substrate from a bottom surface of the base substrate, and a cross-sectional area of each of the plurality of light shielding parts is formed into any one of a wedge shape and a trapezoidal shape.
5. The external light shielding film of claim 2 , wherein each of the plurality of external light shielding parts includes at least one material selected from the group consisting of a black inorganic material, a black organic material, and a metal.
6. The external light shielding film of claim 1 , wherein an external light entering into the lens pattern has an incident angle of about 40 through about 60 degrees.
7. A display filter, comprising:
at least one external light shielding film formed between two successive layers of the display filter, the external light shielding film including a lens pattern formed on a surface of a base substrate and including a plurality of aspheric lenses, and an external light shielding pattern formed on another surface of the base substrate, wherein an aspheric surface (Z) of each of the plurality of aspheric lenses is obtained by
z
(
r
)
=
Cr
2
1
+
1
-
(
1
+
k
)
C
2
r
2
+
Ar
4
+
Br
6
+
Cr
8
+
Dr
10
,
where ‘r’ denotes a radius of a spherical surface, ‘C’ denotes a spherical coefficient, ‘k’ denotes a conic constant, and ‘A’, ‘B’, ‘C’, and ‘D’ denote an integer of 2 through 7, respectively.
8. The display filter of claim 7 , further comprising an anti-reflection film, wherein the external light shielding pattern is formed on a surface of the base substrate to face a direction opposite to the anti-reflection film.