Optical element for lateral light spreading in edge-lit displays and system using same
First Claim
1. An optical system, comprising:
- an image-forming panel having an illumination side and a viewing side;
a light guide disposed to the illumination side of the image-forming panel; and
an illumination light unit, where the light guide is optically between the illumination light unit and the image-forming panel, the illumination light unit comprising one or more light sources capable of generating illumination light and a controlled transmission mirror arranged to receive the illumination light from the one or more light sources, the controlled transmission mirror comprising an input coupling element comprising at least one of a bulk diffuser, a surface diffuser or a structured surface, an output coupling element comprising at least one of a bulk diffuser, a surface diffuser or a structured surface, and a first multilayer reflector disposed between the input and output coupling elements, the first multilayer reflector having a bandedge defined by angle θ
min, wherein the input coupling element diverts at least some of the illumination light incident thereon at an angle less than θ
min into an angle greater than θ
min so that the diverted light is transmitted through the multilayer reflector to the output coupling element, and further wherein illumination light from the output coupling element is coupled into the light guide.
1 Assignment
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Accused Products
Abstract
An illumination light unit has at least one light source that generates illumination light. The unit also includes a reflecting cavity having one or more reflectors and a controlled transmission mirror disposed at an output of the reflecting cavity. The controlled transmission mirror includes an input coupling element, an output coupling element and a first multilayer reflector disposed between the input and output coupling elements. At least some of the illumination light is reflected within the reflecting cavity by the one or more reflectors and is transmitted out of the reflecting cavity through the controlled transmission mirror. The illumination light unit may be used for generating light for space lighting, or for illuminating a display. For example, the unit may be used in a backlight to illuminate a lightguide placed behind a display panel.
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Citations
19 Claims
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1. An optical system, comprising:
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an image-forming panel having an illumination side and a viewing side; a light guide disposed to the illumination side of the image-forming panel; and an illumination light unit, where the light guide is optically between the illumination light unit and the image-forming panel, the illumination light unit comprising one or more light sources capable of generating illumination light and a controlled transmission mirror arranged to receive the illumination light from the one or more light sources, the controlled transmission mirror comprising an input coupling element comprising at least one of a bulk diffuser, a surface diffuser or a structured surface, an output coupling element comprising at least one of a bulk diffuser, a surface diffuser or a structured surface, and a first multilayer reflector disposed between the input and output coupling elements, the first multilayer reflector having a bandedge defined by angle θ
min, wherein the input coupling element diverts at least some of the illumination light incident thereon at an angle less than θ
min into an angle greater than θ
min so that the diverted light is transmitted through the multilayer reflector to the output coupling element, and further wherein illumination light from the output coupling element is coupled into the light guide. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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Specification