LED Lamp for Projector

[JSnigier]

First post from a long-time luker. Recently the UHP bulb on my projector burned out, and being the led fanatic I am deceided that I might be able to solve that problem once and for all.

What is the feasability of doing such a thing?

I understand color tempeture and size are going to be extremely important in this application.

I was thinking that the Rebels may be suitable, but they seem to be a real pain to work with.

There must be some other CPF-er who's contemplated the same thing, what is your take on it?

 

[RustyKnee]

First post from a long-time luker. Recently the UHP bulb on my projector burned out, and being the led fanatic I am deceided that I might be able to solve that problem once and for all.

What is the feasability of doing such a thing?

I understand color tempeture and size are going to be extremely important in this application.

I was thinking that the Rebels may be suitable, but they seem to be a real pain to work with.

There must be some other CPF-er who's contemplated the same thing, what is your take on it?

osram have a version of the OSTAR LED mounted on a board for use in projector applications.

http://www.osram-os.com/ostar-projection/index.php?lan=eng

might give you some ideas.

Stu

 

[txmatt]

I don't think a drop-in replacement is feasible although a projector designed around a specific LED would be doable. The lumen output of projector bulbs is still pretty high for LED-based devices. The projector was designed with a light source with a specific geometry in mind. How will the shape and size of an LED vs the shape and size of a filament or globe impact the image? Finally, the color isn't just color temperature but the entire spectrum. LED's aren't going to emit light with the same spectral output as the original bulb which will have unexpected consequences when it comes to color accuracy of the projected image.

 

[2xTrinity]

I don't think a drop-in replacement is feasible although a projector designed around a specific LED would be doable. The lumen output of projector bulbs is still pretty high for LED-based devices. The projector was designed with a light source with a specific geometry in mind. How will the shape and size of an LED vs the shape and size of a filament or globe impact the image? Finally, the color isn't just color temperature but the entire spectrum. LED's aren't going to emit light with the same spectral output as the original bulb which will have unexpected consequences when it comes to color accuracy of the projected image.

Good points. Also, the projects that use LEDs are more complicated than simply slapping a white LED in there. Most of them use high-powered separate red, green, and blue emitters -- and cycle them off and on in a specific order. This does away with the color wheel -- a rotating filter used in most projectors to rapidly switch between displaying red, green, and blue components of the image. LEDs offer the potential for more saturated color as they can offer more precise color differentiation, and a deeper red than the red/orange produced from the mercury lamp.

However, LEDs are a poor choice for a retrofit because the original projector optics are designed around the use of an ultra-high-pressure mercury lamp. There, the light is concentrated into a single tiny arc, much more concentrated than an incandescent filment, and much, much more concentrated than an LED die.

Even finding one LED is bright enough may not do the job, as the light will be distributed over a larger surface. Using multiple LEDs will be even more diffiuclt to collimate properly. For LEDs to work, all the optics in the entire device will most likely need to be designed with LEDs in mind.

 

[JSnigier]

Thanks so much for all of your replies, I really appreciate it.

I do remember someone overseas on LumenLab doing an LCD projector build using hundreds of 5mm's. The picturues of it did not actually look too bad.

FWIW I have a Canon LV-S1 http://www.projectorcentral.com/Canon-LV-S1.htm

I guess I will just have to wait till the LED projectors start coming out.

 

[IsaacHayes]

Photonic lattice LEDs. Take a look.
http://www.phlatlight.com/home-02.php#normal
http://www.luminus.com/phlatlight/
http://www.luminus.com/products/chipsets.php