A long time ago (1995), in a far-away land (Canada), a vendor helped change the course of CTP history by thinking thermal. At that time, CTP was an emerging technology: After DRUPA 95, an international trade show, industry pundits speculated that the number of CTP vendors may have exceeded the number of actual users. Those platesetters utilized visible-light tech-nology—red or green lasers—for imaging. Even Creo (now CreoScitex), before it pioneered thermal CTP with plate partner Kodak (now Kodak Polychrome Graphics), marketed visible-light units.
A couple of years later, visible-light was still viable, but thermal was the hot technology. Soon, thermal offerings included a variety of solutions from numerous vendors.
By 2000, what went around came around. Despite thermal's dominance, visible-light is back, but in a new form: violet. This year, several companies launched or announced CTP solutions based on violet-laser-diode imaging technology.
Everything's coming up roses
So, why try violet CTP? "Violet offers some nice features over the other visible-light laser sources, [which require darkroom conditions for plate handling]," declares Frank Van Parys, product manager, imaging systems, BARCO Graphics, Gent, Belgium. "The plate suitable for this violet laser diode can be handled in bright-yellow safelight—actually the same environment as the conventional plateroom. In this respect, it's also becoming a competitor to thermal technology, which utilizes plates that can be handled in daylight."
Another appealing characteristic is laser cost. "Unlike thermal lasers, which are produced for a specific niche, violet lasers are mass produced for applications ranging from DVD players to medical research," reports Peter Kushnieruk, senior product marketing manager, output systems, AGFA, Ridgefield Park, NJ. "The more lasers that are produced, the lower the production cost."
Plus, he claims, violet lasers have a long life: "A violet laser is only on as long as it's actually imaging, so you're using less of the laser."