LED LIGHT SOURCES FOR IMAGE PROJECTION SYTEMS

摘要

In accordance with the invention a light source for an image projection system comprises one or more LEDs packaged for high temperature operation. Advantageously, the LED die are disposed on a package comprising a ceramic coated metal base including one or more underlying thermal connection pads, and underlying electrical connection pads, each LEI) die thermally coupled through the metal base to a thermal connection pad and electrically coupled to electrical connection pads. The LED can be mounted directly on the metal of the base or on a thin coating of electrical insulator on the metal. Arrays of LED die thus packaged are advantageously fabricated by the low temperature co-fired ceramic-on-metal technique (LTTC-M) and can be referred to as LTTC-M packaged arrays. The LEDs are advantageously mounted in an array of cavities having tapered sides to reflect light from the LEDs. The high temperature LED light sources can substitute for HID lamps in a variety of front and rear projection systems and displays. They are particularly useful for rear projection systems.