Patent ID: 6747801
Filing Date: 2004-06-08
Classification: G02B

Abstract:
An optical film comprising:a transparent film comprising at least one layer forming at least one surface of said transparent film; an adhesive layer provided on said one surface of said transparent film, said adhesive layer having a refractive index different by 0.1 or less from a refractive index of said at least one layer of said transparent film; and a repetitive prismatic structure provided on the other surface of said transparent film, said repetitive prismatic structure having optical path changing slopes at least a portion of which are aligned in a substantially constant direction at an inclination angle in a range of from 35 to 48 degrees with respect to a plane of said transparent film, wherein a projected area, onto said film plane, of flat surfaces each having an inclination angle of not larger than 5 degrees with respect to said film plane is not smaller than 10 times as large as a projected area, onto said film plane, of the slopes each having an inclination angle of not smaller than 35 degrees with respect to said film plane.