Patent ID: 8107164
Filing Date: 2012-01-31
Classification: G02B

Abstract:
1. A light guiding film comprising: a film base, having a first side and a second side opposite the first side; and at least one microstructure, disposed on the first side or the second side of the film base, and comprising a first surface and a second surface above the first surface, wherein a first inclination angle is between the first surface and a reference plane, the reference plane is perpendicular with the film base, a second inclination angle is between the second surface and the reference plane; whereby a plurality of incident light beams becomes a plurality of output light beams after passing through the light guiding film, an output angle is defined as the angle between the output light beam and the light guiding film, the output angle is defined as 0 degree when the output light beam is downward and parallel with the light guiding film, the output angle is defined as 180 degrees when the output light beam is upward and parallel with the light guiding film, the total energy of the output light beams with the output angles from 85 to 120 degrees is more than 40% of the total energy of the output light beams with the output angles from 0 to 180 degrees.