Patent ID: 6927919

Claim:
A collimating system comprising: a light source having at least one dominant emitting angle at which light having a light intensity distribution, which is relatively greater than a light intensity distribution at other various emitting angles, is emitted; and a collimating lens including at least one prism portion having an exit surface sloping at a prism angle corresponding to the dominant emitting angle, wherein the at least one prism portion satisfies the following relationship: tan ⁢ ⁢ α n = sin ⁢ ⁢ Ω n n 2 - sin 2 ⁢ Ω n - 1 where α n denotes the prism angle of the prism portion, Ω n denotes the dominant emitting angle of the light source, and n is a refractive index of the collimating lens.