'Health Physics' releases findings on safety of laser projectors

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The leading peer-reviewed journal for radiation safety, Health Physics, has reviewed and published a paper entitled Optical Safety of Comparative Theater Projectors in the recently released March 2014 edition. The study found that ocular hazards from projectors—professional to consumer-grade systems—are similar whether their illumination source is laser-based or lamp-based.

The study also points out that laser-illuminated projector emissions hold no resemblance to the optical hazards of collimated laser beams used in light shows and, therefore, laser-illuminated projector standards and regulations should be similar to those for lamp-based projectors, rather than those applied to laser light shows. The study was done to ensure that state-of-the-art laser-illuminated projectors (LIPs) pose no danger to theatre operators and moviegoers as they replace lamp-based systems in theatres and venues worldwide.

“Laser-illuminated projectors are expected to provide many benefits to theatre operators with longer lifetimes, cooler and less expensive operation, more uniform and brighter pictures, delivering a more enjoyable experience for moviegoers, particularly with respect to 3D films,” noted Heidi Hoffman, managing director of the Laser Illuminated Projector Association. “Similar advantages will come to large-venue operators of conference facilities, traffic-control facility operators, and anywhere images are projected onto screens or surfaces.”

The co-authors, a team of radiation and laser safety experts, include Dr. David Sliney, a leading medical physicist; David Schnuelle, Dolby Laboratories; Casey Stack, Laser Compliance; and Jay Parkinson, Phoenix Laser Safety. Measurements were taken of the irradiance and source size, as well as the ultraviolet and infrared emissions of the systems studied. The projectors spanned a wide variation in terms of lumen output, illumination method and beam angles. The beams of light were measured at distances ranging from .1 to 4.0 meters and for a duration of .25 seconds.