AN OPTICAL ENGINE FOR MINIATURE PROJECTION UTILISING A RETRO-REFLECTIVE POLARISATION RECYCLING SYSTEM AND A REFLECTIVE FIELD SEQUENTIAL OR COLOUR FILTER LCOS PANEL

摘要

The present invention relates to an optical engine for a projection system and in particular for a miniaturised device in which a projected image is provided by the use of white or coloured light sources, a light collection system, a light shaping system, a polarisation recycling system, a polarising plate beam splitter, an LCoS (Liquid Crystal On Silicon) panel and an image projection system. The projection optics may also incorporate a cylindrical surface to compensate for aberrations caused by the plate beam splitter. The recycling system ensures the efficiency of the engine wherein light that does not pass through the pre-polariser is reflected back along the optical path to the light source where it is absorbed and re-emitted. This is achieved by having a symmetrical lenslet array that is closely coupled to the prepolariser.