Brightness enhancement with directional wavelength conversion
First Claim
1. An optical illumination system comprising:
- one or more light sources each comprising one or more light emitting devices emitting light in a first wavelength range;
coupling optics that collects and collimates the light from the light sources;
one or more optical fibers or waveguides that couple the collimated light form each light source;
a light cycling cavity having at least one aperture, the light cycling cavity being formed by a wavelength conversion layer that converts the light from the light sources in the first wavelength range into light in a second wavelength range that is different from the first wavelength range;
a light selective filter that passes the collimated light in the first wavelength range and reflects the light in the second wavelength range; and
optics for introducing the collimated light from the optical fibers or waveguides onto an outside surface of the light recycling cavity.
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Accused Products
Abstract
An LED based illumination system with enhanced brightness is described. The system includes one or more light sources such as LEDs, one or more light couplers for efficiently collecting and collimating the light from the light sources, one or more wavelength selective filters, one or more light concentrators that focus the collimated light, and a cavity made of a layer of wavelength converting material such as a phosphorescent material located at the focus planes of the light concentrators. Each light coupler includes a light tunnel portion and a compound parabolic reflecting portion, and effectively collects and collimates light emitted by the LED in all directions. The wavelength selective filters pass the collimated light from the light sources and reflect light of a second wavelength generated by the phosphorescent material. The lights of both wavelengths exit the light cycling cavity through an aperture.
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Citations
17 Claims
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1. An optical illumination system comprising:
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one or more light sources each comprising one or more light emitting devices emitting light in a first wavelength range; coupling optics that collects and collimates the light from the light sources; one or more optical fibers or waveguides that couple the collimated light form each light source; a light cycling cavity having at least one aperture, the light cycling cavity being formed by a wavelength conversion layer that converts the light from the light sources in the first wavelength range into light in a second wavelength range that is different from the first wavelength range; a light selective filter that passes the collimated light in the first wavelength range and reflects the light in the second wavelength range; and optics for introducing the collimated light from the optical fibers or waveguides onto an outside surface of the light recycling cavity. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. An illumination device, comprising:
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a plurality of light emitting devices each emitting light in a first wavelength range; a light selective filter that transmits light in the first wavelength range and reflects light in a second, different wavelength range, the light selective filter placed in an optical path of the light from the light emitting devices; a light concentrator placed in the optical path to receive transmitted light through the light selective filter from the light emitting devices, the light concentrator configured to focus the light at a plane displaced from the light concentrator; and a wavelength conversion layer placed at the plane to receive the focused light from the light selective filter and the light concentrator, the wavelength conversion layer operable to absorb light in the first wavelength range and to emit light in the second wavelength range, wherein the light selective filter is located between the light emitting devices and the wavelength conversion layer to reflect light in the second wavelength range towards the wavelength conversion layer.
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Specification