CurtPalme.com Home Theater Forum

jbltecnicspro · Joined: 23 Apr 2016 Posts: 512

Do you all think we'll ever see OLED projectors? I think the idea, in theory at least, sounds like a kick-ass option. Self-illuminating panels, no lamps, pure blacks. It would essentially be what OLED is to CRT in the television realm - a smaller, quieter, more convenient CRT projector.

Now I think the biggest issue with this is that blue OLED's are pretty prone to burn-in. Kind of like how old CRT projectors wore out the blue tubes first. But I don't know - a man can dream.

dvh99 · Joined: 25 Dec 2009 Posts: 2158 Location: nederland

oled is a panel technology and blue lasts the longest.
did you ever own a crt pj? i guess not.

jbltecnicspro · Joined: 23 Apr 2016 Posts: 512

I guess I'm not following your answer. OLED is a panel technology, true - but so is LCD and LcOS - which are both found in projectors. I didn't know that blue lasts the longest - I always thought it was the other way around.

I'm not sure I understand your question about owning a CRT projector. I briefly owned a G70 projector. My comment about the blue tubes wearing out faster was in regards to older models like the Sony 127x projectors and Barco 801's. I'm aware that newer, brighter machines consumed the green tubes first.

cmjohnson · Joined: 03 Apr 2006 Posts: 5180 Location: Buried under G90s

There are difficulties involved with trying to make an active LED panel based projector.

First and foremost, the issue of thermal management rears its ugly head.

If the imaging device is also going to be the source of all the light in the projected image, then that immediately should alert you to the issue of power density and heat management issues.

To keep the cost of optical systems down to something reasonable, a smaller imaging device is desired. That increases the energy density of the imaging device. So it will run hotter.

To make it run cooler, make it larger. But that increases the cost of the optics.

Assume a happy medium, say an imaging device that's about an inch wide.

You've got to generate a high resolution, full color image that's bright enough to fill a good sized screen at a brightness level that satisfies the customers.

A 400 watt lamp is well within the typical power range of most digital projector lamps today. Assume half that power is wasted,
and you can do it with half that if the imaging devices are the light source as well.

That's still a 200 watt light source that's smaller than a lamp and it can't be allowed to run as hot as any lamp.

I don't expect to see any active emitter panels driving any projectors any time soon. Eventually, yes, but not for years to come.

jask · Joined: 17 Mar 2006 Posts: 10187 Location: kamloops BC

you are comparing low power emissive vs high power (lumen) transmissive imaging systems.... an image from a low emissive device can not emit enough light to project an image comparable to a system that works like a high power light passing through a transmissive colour panel. If you look at state of the art CREE type LEDs they require discreet lenses to focus. High power full spectrum emitters are not powerful enuough or compact enough to create an array that would render any kind of commercial quality image less than signboard or billboard size. The dominant hurdle- as has been mentioned, is heat. these diodes are resistive emitter diodes - current sinks, and if you can find a way to create the lumen output of a diode without the resistive loss( heat) you will be a very very rich person. Those efficiencies could change every aspect of how we use electricity... and defy the known laws of physics.