Large Format Laser
Active Cooling in Large Format Laser Projectors
Digital Projection, Ltd is a digital imaging pioneer and manufacturer of high-performance DLP® projectors. Their products are used in a wide range of demanding applications, particularly for large-venues, such as live-event staging, command & control, digital cinema, and commercial entertainment. Notably, the company was recognized by the Academy of Television Arts and Sciences for winning two Emmy® Awards for Outstanding Achievement in Engineering Development. Digital Projection is uniquely the “first and only” projector manufacturer to win this prestigious award!
To achieve screen sizes of 30 meters or more requires high brightness diode laser arrays with red, green and blue wavelengths in order to project the RGB image onto the screen. High power lasers are used for large area illumination. These lasers require active cooling–not only for heat dissipation–but also to ensure stable light output.
We talked with Dermot Quinn, Chief Technical Officer, and Mark Wadsworth, Vice President of Global Marketing, from Digital Projection:
“In the first of the production versions of our Satellite platform, we built what we called our stage three version of the laser light source, but it didn’t have an integral chiller. It relied on some form of external cooling. And I made it one of the statements of success for our new laser light source, that in a 4U high rack mount enclosure, we would have integral cooling and an ultra-stable laser light source,” Quinn said.
He added, “And Aspen’s solution has helped us to do just that. So our production version of light source has your compact, liquid chiller module integrated, and it is instrumental in enabling us to achieve that goal. We’re using your chiller to cool our RGB diode lasers. And that gives us flexibility to run that liquid cooling around various places within our laser source.”
Quinn continued, “With the compact size of Aspen’s liquid chiller module (LCM) system, we’re able to integrate it into our 4U rack mount, which houses the lasers, power supplies and electronics. I think that’s the critical issue, where we set ourselves this integration goal, and you’ve helped us to achieve it. It’s a beautiful little compressor, it’s quiet, it’s got a good thermal ratio and it appears to be able to remove something like three times as much heat as it consumes. So it’s compact, efficient and quiet. And those things are instrumental in helping us to achieve our goal.
Wadsworth said, “Also, we offer our customers the ability to operate this laser projector at varying power levels. So from around 30% up to 100% power, and also in a range of ambient environments. We exploit the fact that the compressor is variable speed, where we can match the heat load to cooling power of the LCM. We have our own feedback loop within our system that enable us to control the compressor accordingly. The efficiency and light output of laser diodes has enabled us to create this compact light source. It is a real benefit for us to be able to maintain a stable temperature particularly for the red lasers.”
Quinn added, “So what Aspen has done is taken away the hard part for us, the refrigeration module, and obviously, the small size is quite unique. You guys are good to deal with, you know what you’re talking about, and if we ask a question, we get a clear answer.”
Based upon their experience and innovation, Digital Projection has a bright future.