LIGHT RECYCLING HOLLOW CAVITY TYPE DISPLAY BACKLIGHT

摘要

A front reflector (610) in a hollow cavity backlight (600) has asymmetrically reflective properties due to a film of alternating polymer layers recycling the light. The backlight addresses the need for thinner, lighter, large-area devices with fewer components but defined output polarisation and adequate viewing angles. A uniform light distribution in the guide and a directed output light (662) distribution are necessary. A front reflector (610) has a partial reflectivity for one polarisation state (662a) and a high reflectivity for the orthogonal state (666), wherein the partial reflectivities of the desired output polarisation state differ according to according to incident s- and p- polarisation states. There is also an asymmetric front reflector reflecting all light of one incidence angle distribution but partially reflecting & transmitting other light. A conversion structure in the cavity converts light of the first distribution into the second distribution. Application: displays or general lighting.