TIR receives patent for LED-based clean-room illumination

April 5, 2005
TIR Systems Ltd. has been granted what it describes as a "milestone" patent by the US Patent & Trademark Office (USPTO).

US patent number 6,871,983 entitled "Solid-state continuous sealed clean room light fixture" was filed in October 201. The company describes it as the first to be granted to TIR from a growing portfolio of over 40 filed patent applications in the field of solid-state lighting (SSL) for general lighting applications.

The patent describes an LED ceiling light fixture for clean rooms, which are typically used in the manufacture of semiconductor ICs or other products which are highly sensitive to dust, moisture or other contaminants.

LEDs offer longer lifetimes than commonly-used fluorescent tubes, with consequent maintenance and replacement advantages. The risk of contamination through breakages is removed with LED fixtures, which also occupy much less space.

The invention described is 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, and 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. Furthermore, lens and/or filters 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.

TIR says that the patent covers lighting fixtures incorporating certain enabling technologies that are the basis of a universal platform which the company will make available to the lighting industry this year.

The platform is intended to provide superior performance in a standardized format, which can be adopted by TIR and its partners in products that utilize LEDs as a light source.

“This patent is a key piece of our intellectual property [IP] portfolio because it protects our technology in one of the important applications that will lead us directly into the mainstream of lighting,” said Brent York, Chief Technology Officer of TIR Systems.

York added, “While a substantial amount of our IP portfolio supports the technologies surrounding our universal platform for enabling SSL illumination, it is also critical to ensure that the products that will provide market access for the platform are also protected in the early days of a disruptive technology like SSL.”