Patent ID: 7768710

Claim:
An optical film having a uniform luminous flux, comprising a plurality of light-collecting units, wherein said plurality of light-collecting units has a symmetrical arrangement; wherein said plurality of light-collecting units has a first base angle and a second base angle; wherein each of said base angles is between 35 degrees (°) and 55°; wherein said light-collecting unit has a first apex angle, a second apex angle and a third apex angle; wherein each of said first, said second and said third apex angles is between 80° and 100°; wherein respective vertical distances between vertices of said first, said second and said third apex angles and a base of said light-collecting unit has a ratio of 22:21±60%:18; and wherein vertices of said first, said second and said third apex angles are straightly vertical to said base of said light-collecting unit at three points to obtain a length ratio of 22:15±60%:25±60%:18 by dividing said base of said light-collecting unit with said three points.