摘要:
A backlight unit (10) has a hollow cavity (16) instead of employing a light guide. One or more light sources (24a-c), such as LEDs, are arranged to emit light into the cavity, which is formed by a front (12) and a back reflector (14). The backlight is typically of the edge-lit type. The backlight can have a large area, is thin and consists of fewer components than conventional devices. Its design permits light recycling. The unit emits light of a predefined polarisation and can be arranged to have desired horizontal/vertical viewing angle properties. Light is uniformly distributed within the guide and the light output (20b, 2Od) is substantially collimated. Such backlights occupy a specific region in a parameter space defined by two parameters: first, the ratio of the output emission area to the total source emission area should lie in the range 0.0001 to 0.1; and second, the ratio of the SEP to the height of the cavity (H) should be in the range 3 to 10, where the SEP is an average plan view source separation, a special measure of the average spacing of light sources in the plane of the unit. There is also a discussion on the required number of light sources N, their arrangement near the periphery of the cavity, as well as the shape and size of the output emission area. A required minimum brightness uniformity (VESA) value to be maintained, when a subset of Madjacent sources is switched off (where M is at least 0.1 N or M>2 or both), is also disclosed. The backlight can be used for a display or for general lighting purposes.
摘要:
An illumination system including a light source, light guides coupled to the light source, each including an input surface and an output surface, emissive material positioned to receive light from at least one light guide, and an interference reflector positioned such that the emissive material is between the output surfaces of the light guides and the interference reflector is disclosed. The light source emits light having a first optical characteristic. The emissive material emits light having a second optical characteristic when illuminated with light having the first optical characteristic. The interference reflector substantially transmits light having the second optical characteristic and substantially reflects light having the first optical characteristic.
摘要:
A light source including an LED that emits excitation light, a layer a phosphor material positioned to receive the excitation light, the phosphor material emitting visible light when illuminated with the excitation light, and a first non-planar flexible multilayer reflector that reflects the excitation light and transmits visible light. The non-planar flexible multilayer reflector is positioned to reflect LED light onto the phosphor material.
摘要:
An illumination system including a light source, a light guide including an output surface, emissive material positioned between the light source and the output surface of the light guide, and an interference reflector positioned between the emissive material and the output surface of the light guide is disclosed. The light source emits light having a first optical characteristic. The emissive material emits light having a second optical characteristic when illuminated with light having the first optical characteristic. The interference reflector substantially transmits light having the second optical characteristic and substantially reflects light having the first optical characteristic.
摘要:
An illumination system including a light source, a light guide including an output surface, emissive material positioned to receive light from the output surface of the light guide, and an interference reflector positioned such that the emissive material is between the output surface of the light guide and the interference reflector is disclosed. The light source emits light having a first optical characteristic. The emissive material emits light having a second optical characteristic when illuminated with light having the first optical characteristic. The interference reflector substantially transmits light having the second optical characteristic and substantially reflects light having the first optical characteristic.
摘要:
The present invention provides reflective films and other optical bodies which exhibit sharp bandedges on one or both sides of the main reflection bands. The optical bodies comprise multilayer stacks M.sub.1 and M.sub.2, each having first order reflections in a desired part of the spectrum and comprising optical repeating units R.sub.1 and R.sub.2, respectively. At least one of the optical repeating units R.sub.1 and R.sub.2 varies monotonically in optical thickness along the thickness of the associated multilayer stack.
摘要:
An edge-lit backlight comprises a front and back reflector forming a hollow light recycling cavity having a cavity depth H and an output region of area Aout, and one or more light sources disposed proximate a periphery of the backlight to emit light into the light recycling cavity. The light sources have an average plan view source separation of SEP collectively having an active emitting area Aemit, wherein a first parameter equals Aemit/Aout and a second parameter equals SEP/H. The first parameter is in a range from 0.0001 to 0.1, and by the second parameter is in a range from 3 to 10. The front reflector has a hemispherical reflectivity for unpolarized visible light of Rfhemi, and the back reflector has a hemispherical reflectivity for unpolarized visible light of Rbhemi, and Rfhemi*Rbhemi is at least 0.70.
摘要:
Multilayer optical films having one or more reflection bands are provided. The films include alternating polymeric layers configured to selectively reflect and transmit visible light at a design angle of incidence, where the selective reflection includes first and second visible reflection bands. At least one of the first and second visible reflection bands is a first-order reflection.
摘要:
Multilayer optical films having one or more reflection bands are provided. The films include alternating polymeric layers configured to selectively reflect and transmit visible light at a design angle of incidence, where the selective reflection includes first and second visible reflection bands. At least one of the first and second visible reflection bands is a first-order reflection.
摘要:
An illumination system including a light source, a light guide including an output surface, emissive material positioned to receive light from the output surface of the light guide, and a first interference reflector positioned between the output surface of the light guide and the emissive material is disclosed. The light source emits light having a first optical characteristic. The emissive material emits light having a second optical characteristic when illuminated with light having the first optical characteristic. The first interference reflector substantially transmits light having the first optical characteristic and substantially reflects light having the second optical characteristic.