It's worth noting IMAX does in fact have a trademark in the relevant fields -
": Consumer electronic products, namely, headphones, earphones, cables, camcorders, DVD players and stereos; home theater systems comprised of a projector system, a surround sound system, a screen, media servers and control devices; and gaming equipment, namely, video game machines for use with televisions and computers; video game controllers; computer software for playing video games and for accessing and browsing global computer and communications networks; video game programs downloadable from global computer networks and global communications networks; and user manuals for all of the aforementioned software and devices sold as a unit therewith; devices used to facilitate interactive game play over computer networks; television and video converters; speakers, loudspeakers systems"
": Consumer electronic products, namely, headphones, earphones, cables, camcorders, DVD players and stereos; home theater systems comprised of a projector system, a surround sound system, a screen, media servers and control devices; and gaming equipment, namely, video game machines for use with televisions and computers; video game controllers; computer software for playing video games and for accessing and browsing global computer and communications networks; video game programs downloadable from global computer networks and global communications networks; and user manuals for all of the aforementioned software and devices sold as a unit therewith; devices used to facilitate interactive game play over computer networks; television and video converters; speakers, loudspeakers systems"
http://tmsearch.uspto.gov/bin/showfield?f=doc&state=4808:77u...