Backlight and display system using same

• Main Authors: DERKS, KRISTOPHER JAMES, WEBER, MICHAEL FRANCIS, SCHARDT, CRAIG RUSSELL, OUDERKIRK, ANDREW JOHN, FREIER, DAVID GEORGE, JORDAN, MYRON KENNETH, HEBRINK, TIMOTHY JOHN, KIVEL, EDWARD JAMES, NEVITT, TIMOTHY JOSEPH, BIERNATH, ROLF WERNER, YANG, ZHAOHUI, WHEATLEY, JOHN ALLEN, BRYAN, WILLIAM JAMES
• Format: Patent
• Language: Chinese; English
• Published: 11.08.2014
• Subjects: BLASTING; DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH ISMODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THEDEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY,COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g.SWITCHING, GATING, MODULATING OR DEMODULATING; FREQUENCY-CHANGING; FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMSTHEREOF; HEATING; LIGHTING; MECHANICAL ENGINEERING; NON-LINEAR OPTICS; NON-PORTABLE LIGHTING DEVICES; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICAL LOGIC ELEMENTS; OPTICS; PHYSICS; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHERARTICLES, NOT OTHERWISE PROVIDED FOR; SYSTEMS THEREOF; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLEEXTERIORS; WEAPONS

An asymetric reflective film is disclosed. Such a film can be used as the front reflector (610) in a hollow cavity backlight (600), which recycles the light. The film consists of alternating polymer layers, whose arrangement and refractive indices are appropriately tailored. Such a 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 cavity and a directed output light (662) distribution are necessary. The 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. A further backlight design is disclosed which comprises a front reflector, which reflects substantially all light of a first incidence angle distribution but partially reflects and transmits