External light shielding film and optical filter for display apparatus having the same
View Patent ↗Disclosed is an external light shielding film. The external light shielding film comprises a transparent substrate; and an external light shielding pattern formed on a surface of the transparent substrate and including a plurality of external light shielding parts. Each of the plurality of external light shielding parts has a polymer resin and at least one color-changeable colorant. The color of the plurality of external light shielding parts may vary according to an external heat source or vary depending on an intensity of an external light source, thereby improving a contrast ratio in a bright room, and a specific color may be visible even when the power of the display apparatus is OFF, thereby achieving an interior decorative effect.
1. An external light shielding film, comprising:
a transparent substrate; and
an external light shielding pattern formed on a surface of the transparent substrate and including a plurality of external light shielding parts,
wherein each of the plurality of external light shielding parts has a polymer resin and at least one color-changeable colorant.
2. The film of claim 1 , wherein the polymer resin includes at least one of an acrylic-based resin, a silicon resin, and a urethane resin.
3. The film of claim 1 , wherein the color-changeable colorant is a photochromic colorant whose color varies depending on a wavelength of an external light source.
4. The film of claim 3 , wherein the color of the photochromic colorant varies depending on a wavelength of a light in an ultraviolet ray range.
5. The film of claim 3 , wherein the photochromic colorant is irreversibly changed into a black color by irradiation of a light.
6. The film of claim 1 , wherein the color-changeable colorant includes at least one colorant selected from the group consisting of spiropyran-based colorants, thionine-based colorants, diarylethene-based colorants, and diazo-based colorants.
7. The film of claim 1 , wherein each of the plurality of external light shielding parts further includes a photochromic colorant and an ultraviolet initiator forming a radical by ultraviolet ray.
8. The film of claim 7 , wherein the ultraviolet initiator includes at least one substance selected from an oxide-based compound and an azo-based compound.
9. The film of claim 1 , wherein the color-changeable colorant is a thermochromic colorant whose color varies depending on an ambient temperature of the colorant.
10. The film of claim 1 , wherein each of the plurality of external light shielding parts includes 0.1 to 100 parts by weight of a color-changeable colorant with respect to 100 parts by weight of a solid content of the polymer resin.
11. The film of claim 1 , wherein each of the plurality of external light shielding parts has a wedge form in its cross-sectional shape, and a stripe form when viewed from the top.
12. The film of claim 1 , further comprising:
a support body adhered to a surface of the substrate.
13. An optical filter for a display apparatus, comprising:
a plurality of functional films; and
an external light shielding film disposed between at least two adjacent functional films, the external light shielding film comprising:
a transparent substrate; and
an external light shielding pattern formed on a surface of the transparent substrate and including a plurality of external light shielding parts,
wherein each of the plurality of external light shielding parts has a polymer resin and at least one color-changeable colorant.