Light blocking layer, display filter having the light blocking layer, and display apparatus having the display filter

1. An external light-shielding layer for a display filter, the external light-shielding layer comprising:

a base substrate comprising a transparent resin; and

wedge-shaped light-shielding patterns spaced apart from each other on a surface of the base substrate at predetermined intervals, and made of a resin comprising a coloring agent, the coloring agent having a concentration of about 0.5% to about 1.5% by weight in the wedge-shaped light-shielding patterns,

wherein each of the wedge-shaped light-shielding patterns comprises a bottom surface exposed on one surface of the substrate and inclined surfaces extending from the bottom surface and forming a wedge-shaped groove in the substrate, and the bottom surface faces a side opposite to a direction from which an external light comes,

wherein a refractive index difference between the base substrate and the light-shielding patterns is less than or equal to 0.05,

wherein an area ratio of the bottom surface of the light-shielding patterns to the surface of the base substrate corresponds to about 20% to 50% and a contrast ratio is greater than or equal to about 250:1 when the visible light transmittance is maintained to be greater than or equal to about 50%.

2. The external light-shielding layer of claim 1 , wherein an incident light on the external light-shielding layer is refracted via the light-shielding pattern without a total reflection in the light-shielding pattern, and passes through about 12 μm to about 20 μm of the light-shielding pattern.

3. The external light-shielding layer of claim 1 , wherein the coloring agent is carbon black, acetylene black, aniline black, and black metal.

4. The external light-shielding layer of claim 1 , wherein the external light-shielding layer has a transmittance greater than or equal to about 70% in a visible spectrum.

5. The external light-shielding layer of claim 1 , wherein the external light-shielding layer is shaped as black stripes.

6. The external light-shielding layer of claim 1 , wherein a pitch between the light-shielding patterns corresponds to about 70 μm to about 110 μm.

7. The external light-shielding layer of claim 1 , wherein the light-shielding pattern has a lower refractive index than the base substrate.

8. A display filter comprising:

a filter base; and

the external light-shielding layer according to claim 1 generated in a surface of the filter base.

9. The display filter of claim 8 , wherein the filter base has at least one of functions consisting of an antireflection, an electromagnetic shielding, a shielding of near infrared light, a color correction.

10. A display apparatus comprising:

panel assembly comprising a front substrate and a rear substrate which are coupled corresponding to each other and a plurality of cells between the front substrate and the rear substrate; and

the display filter of claim 8 located corresponding to the front substrate of the panel assembly.

11. A display apparatus comprising:

a panel assembly comprising a front substrate and a rear substrate which are coupled corresponding to each other and a plurality of cells between the front substrate and the rear substrate; and

a display filter located corresponding to the front substrate of the panel assembly, wherein:

the display filter comprises a filter base, and the external light-shielding layer according to claim 1 generated in a surface of the filter base, and

the display apparatus is a plasma display panel apparatus.