Automotive lamp

1. A vehicle lamp comprising:

a lamp chamber containing at least one light source in an interior thereof and having a light-emitting opening;

a lamp cover attached to said light-emitting opening, said lamp cover comprising a transparent cover body having a configuration and size capable of covering at least a light emission surface of said lamp; and

a polarizing film applied to an inner surface of said cover body, said polarizing film having fine textured structures on a surface thereof for changing color of the exterior of said lamp when the light source is in a lit condition compared to an unlit condition, wherein said fine textured structures includes prisms having a pitch p of not more than 1 mm and an apex angle α of said prisms is not more than 150°.

2. A vehicle lamp according to claim 1 , wherein said textured structures are fine textured structures exhibiting special optical characteristics such that the exterior of said lamp changes color when the light source is in a lit condition compared to an unlit condition.

3. A vehicle lamp according to claim 1 , wherein said textured structures are fine prisms and said polarizing film is a prism sheet such as that useful in a back light for a liquid crystal display panel.

4. A vehicle lamp according to claim 1 , wherein said lamp further comprises a cover color such that light from said light source acquires a predetermined functional color when emitted through said lamp cover out of said lamp chamber, and the functional color and the cover color are different from each other.

5. A vehicle lamp according to claim 1 , wherein said lamp further comprises a cover color, and said polarizing film is a prism sheet that prevents the recognition of the color of the light source under unlit conditions so that only the cover color can be seen under unlit conditions and a color difference can be seen under lit conditions.

6. A vehicle lamp according to claim 1 , wherein said polarizing film transmits P polarized heht and reflects S polarized light, and the reflected S polarzed light is transmitted through said polarizing film after the polarization is removed from the light upon its multiple reflection.

7. A vehicle lamp according to claim 1 , wherein said polarizing film is a prismatic-structured film and said fine textured structures are prismatic structures.

8. A vehicle lamp according to claim 1 , wherein said polarizing film is a luminance increasing film.

9. A vehicle lamp according to claim 1 , wherein said vehicle lamp further comprises a filter element between said light source and said lamp cover.

10. A vehicle lamp according to claim 1 , wherein the color of said cover body and the color of the light outwardly emitted through said polarizing film from said light source are different.

11. A vehicle lamp according to claim 1 , wherein said vehicle lamp is a separated chamber type lamp structure comprising at least two lamp chambers each having a light source, and the color of at least one lamp chamber is different under lit and unlit conditions.

12. A vehicle lamp according to claim 11 , wherein said vehicle lamp is used as a rear combination lamp of at least two lamps, from the group consisting of a brake lamp, a tail lamp, a brake and tail lamp, a turn-signal lamp and a back-up lamp, are contained in an opitonal pattern and combination, with the color of one of said lamps being different than the color of another of said lamps under lit conditions.

13. A vehicle lamp according to claim 12 , wherein said lamp includes a turn-signal lamp and a brake lamp, said turn signal lamp is the same color under lit and unlit conditions, and said brake lamp is a different color under lit and unlit conditions, with the color of said brake lamp being different than the color of said turn-signal lamp under lit conditions.

14. A vehicle lamp according to claim 13 , wherein the color of said brake lamp is the same as the color of said turn-signal lamp under unlit conditions.

15. A vehicle lamp according to claim 1 , wherein said polarizing film is a single polarizing layer.

16. A vehicle lamp according, to claim 15 , said single polarizing layer isa single selective polarizion layer.

17. A vehicle lamp according to claim 16 , wherein single selective polarizing layer is formed, in a predetermined pattern, with structure portions of a finely textured structural surface and non-structure portions not having such a textured structural surface.

18. A vehicle lamp according to claim 17 , wherein the inner surface of said lamp cover is formed with said selective polarizing layer by processing the patterns of said structure portions and said non-structure portions.

19. A vehicle, lamp according to claim 17 , wherein the transparency degree, defined as an area ratio between said structure portions and said non-structure potions, of said selective polarizing layer is the range of 5 to 90%.

20. A vehicle lamp according to claim 17 , wherein said structure portions or said non-structure portions of said selective polarizing layer are formed of a pattern of selected one of stripes, grids, dots and a combination thereof.

21. A vehicle lamp according to claim 1 , wherein said lamp cover is colored.

22. A vehicle lamp according to claim 1 , wherein said lamp cover has the function of a lens.

23. A vehicle lamp according to claim 1 , wherein said textured structures are located on only one surface of said polarizing film.

24. A vehicle lamp according to claim 1 , wherein said textured structures are located on only one surface of said polarizing film, which is facing toward said light source.

25. A vehicle lamp according to claim 1 , wherein said textured structures are located on only one surface of said polarizing film, which is facing toward said lamp cover.

26. A vehicle lamp according to claim 1 , wherein said textured structures are prism structures located on only one surface of said polarizing film.