Patent ID: 7120346

Claim:
A light tunnel comprising: a light guide path having a form of a hollow tube having inner surfaces to reflect and guide light; a light entrance, having an aperture, at one end of the light guide path to allow light to enter the light guide path; and a light exit, having an aperture, at the other end of the light guide path to emit the light guided by the light guide path, wherein of the inner surfaces of the light guide path comprise inclined surfaces inclined in a manner that aperture of the light guide path increases towards the light entrance, the inclined surfaces of the light guide path being connected to the light entrance, wherein the aperture of the light entrance is larger than the aperture of the light exit; and wherein the light tunnel has an A value of substantially ⅙, where A is ratio 1/L assuming that the light tunnel has a total length of L, and each of the inclined surfaces in the light tunnel in a direction parallel to a light guide path has a length of 1.