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A clean room ceiling light fixture formed as a sealed housing with a downwardly-directed light emitting aperture. A heat sink fixed within and spaced from the housing defines a cable raceway inside the housing. A plurality of LEDs are mounted on the heat sink. A high refractive index (polycarbonate)

A clean room ceiling light fixture formed as a sealed housing with a downwardly-directed light emitting aperture. A heat sink fixed within and spaced from the housing defines a cable raceway inside the housing. A plurality of LEDs are mounted on the heat sink. A high refractive index (polycarbonate) reflector coupled to each LED efficiently directs the LED's light through the aperture into the clean room. The LEDs and/or reflectors can be anti-reflectively coated to improve light transmission efficiency. A refractive index matching compound applied between each LED-reflector pair further improves light transmission efficiency. A spectrally selective filter material prevents ultraviolet illumination of clean rooms used for lithographic processes which are compromised by ultraviolet rays. A holographic diffusion lens and/or variable transmissivity filter can be provided to uniformly distribute the LEDs' light through the aperture. The fixture can be sized and shaped for snap-fit engagement within the H-Bar type clean room ceiling.

대표청구항 ▼

1. A light fixture for a clean room ceiling formed by a plurality of frame members arranged in an H-Bar configuration, the light fixture comprising:(a) a sealed housing module sized and shaped for removably replaceable engagement within the ceiling frame members, the module having a downwardly-direc

1. A light fixture for a clean room ceiling formed by a plurality of frame members arranged in an H-Bar configuration, the light fixture comprising:(a) a sealed housing module sized and shaped for removably replaceable engagement within the ceiling frame members, the module having a downwardly-directed light emitting aperture; (b) a heat sink fixed within the module and spaced from an internal wall of the module to define a cable raceway between the heat sink and the internal wall; (c) a plurality of light-emitting diodes mounted within the module on the heat sink, each one of the light-emitting diodes having a lens for directing light emitted by the one of the light-emitting diodes through the aperture into the clean room; and, (d) a power supply for applying drive current to the light-emitting diodes. 2. A light fixture as defined in claim 1, each one of the light-emitting diodes further having a reflector for directing light emitted by the one of the light-emitting diodes through the aperture into the clean room.3. A light fixture as defined in claim 1, further comprising an anti-reflective coating on each one of the lenses.4. A light fixture as defined in claim 2, further comprising an anti-reflective coating on each one of the reflectors.5. A light fixture as defined in claim 2, wherein the reflectors are formed of a high refractive index material.6. A light fixture as defined in claim 5, wherein the high refractive index material is polycarbonate.7. A light fixture as defined in claim 2, further comprising, for each one of the lenses and an adjacent one of the reflectors, a refractive index matching compound applied between the one of the lenses and the adjacent one of the reflectors.8. A light fixture as defined in claim 7, wherein the refractive index matching compound is an elastomer.9. A light fixture as defined in claim 2, wherein the reflectors are formed of a spectrally selective filter material.10. A light fixture as defined in claim 9, wherein the spectrally selective filter material is a deep dyed polyester.11. A light fixture as defined in claim 9, wherein the spectrally selective filter material is a spectrally selective thin film filter material.12. A light fixture as defined in claim 1, further comprising, a holographic diffusion lens for uniformly distributing, through the aperture, the light emitted by the light-emitting diodes.13. A light fixture as defined in claim 12, wherein the holographic diffusion lens further comprises a structured surface prismatic film.14. A light fixture as defined in claim 1, further comprising; a variable transmissivity filter for uniformly distributing, through the aperture, the light emitted by the light-emitting diodes.15. A light fixture as defined in claim 1, wherein the module is removably magnetically attachable to the ceiling frame members.16. A light fixture as defined in claim 1, wherein the module is removably adhesively attachable to the ceiling frame members.17. A light fixture as defined in claim 1, wherein the power supply further comprises an uninterruptible power supply.18. A light fixture as defined in claim 1, wherein the power supply further comprises an in-line DC-DC converter coupled between a high voltage DC power supply and the fixture.19. A light fixture as defined in claim 17, wherein the power supply further comprises an in-line DC-DC converter coupled between the uninterruptible power supply and the fixture.20. A light fixture as defined in claim 17, wherein the uninterruptible power supply is located at a remote location from the fixture.21. A light fixture as defined in claim 19, wherein the uninterruptible power supply is located at a remote location from the fixture.22. A light fixture as defined in claim 18, wherein the DC-DC in-line converter is located closely proximate to the fixture.23. A light fixture as defined in claim 19, wherein the DC-DC in-line converter is located closely proximate to the fixture.24. A light fixture as defined in claim 21, wherein the DC-DC in-line converter is located closely proximate to the fixture.25. A light fixture as defined in claim 1, wherein the power supply further comprises a regulator for regulating the drive current as a function of time.26. A light fixture as defined in claim 25, further comprising a light sensor located in the clean room and electrically connected to the regulator, the light sensor producing an output signal representative of light intensity near the light sensor, and wherein the regulator further regulates the drive current as a function of the output signal.27. A light fixture as defined in claim 25, further comprising a light sensor located in the clean room and electrically connected to the regulator, the light sensor producing an output signal having a magnitude representative of light intensity near the light sensor, and wherein the regulator further regulates the drive current in inverse proportion to the output signal magnitude.28. A light fixture as defined in claim 1, further comprising a programmable controller electrically connected between the power supply and the light-emitting diodes, the programmable controller for programmatically regulating the drive current as a function of time.29. A light fixture as defined in claim 1, further comprising a programmable controller electrically connected between the power supply and the light-emitting diodes, the programmable controller for programmatically regulating the drive current as a function of time to maintain substantially constant light flux output of the light-emitting diodes.