Lasers and optics bring high resolution to flat-panel displays
Lasers and optics bring high resolution to flat-panel displays
In early 1992, Advanced Laser Technologies (ALT; Carpinteria, CA) developed a laser-based beam actuator that was implemented in a prototype 120-page/minute document scanner. Now, the company is turning the technology toward high-resolution flat-panel displays with the introduction of Thinline, a laser-driven flat digital display. Accordingly, the company has developed a proof-of-concept, single-color model. The proto type, a 17-in.-diagonal, 8 1/4-in.-deep display provides an 8-bit gray scale and refresh rates of 60 frames per second.
"With a spot size of 100 µm," says Don Conne mack, the in ventor of the Thinline display and ALT vice president of research and development, "the prototype display has a resolution of 640 ¥ 480. However, we have de mon strated a de vice that is capable of 4-µm resolution, furnishing the user with a 6000-dot/in. resolution.
In operation, a laser beam is first focused simultaneously on multiple facets of a polygon. Then, a high-speed electronic control circuit focuses the main beam onto a facet of the rotating polygon, which, in turn, reflects the beam toward a target. The circuit is capable of controlling multiple beams and focusing them onto adjacent facets of the rotating polygon. Placing multiple beams on the polygon makes up the x axis of the display. And because each facet tilts around the circumference of the polygon, a y axis is also created.
"The number of facets on the polygon and the number of beams deep on each facet are directly related to the number of lines the display can have," remarks Connemack. The laser can be split wide or deep across the polygon or up and down to optimally write multiple lines of the image at a time. The only limit to resolution is how small the laser beam can be focused.
Currently, ALT is working on a 31-in.-diagonal ¥ 4-in.-deep preproduction, full-color model. Philip Eatherton, ALT president, expects to deliver this unit to licensee manufacturers by mid-1998, and lightweight monitors could be market-ready in 1999. For more information contact Philip Eatherton at (303) 979-6001.