LIGHT TUNNEL AND PROJECTION APPARATUS HAVING THE SAME

摘要

A light tunnel (532) for standardising the intensity distribution of light emitted from a light source (520) comprises four trapezoidal reflective surfaces, an incident plane (532a) and an emitting plane (532b). The size of the emitting plane (532b) is larger than that of the incident plane (532a) and the emitting plane (532b) is inclined at a certain angle (¸) relative to the incident plane (532a). The degree of optical separation and image forming efficiency of an illumination light is improved relative to prior rectangular, wedge and taper type light tunnels. The improved optical separation also results in an improved contrast ratio, while allowing the optical system, and a projection apparatus comprising the optical system, to be compact.