LCD Projector light - LEDs / HID light?

[wechnivag]

I am in the position that i believe many have faced - LCD projector light has gone 'poof', and a quick check online shows that replacement bulbs are in the order of $200-300 dollars.

I was wondering if any LED / lighting experts here have tried or though about DIYing a LCD projector replacement light? Is it doable?

A quick read online suggested that the LCD panel only lets about 10% of light through, so for a 1000 lumen projector, we would need a 10,000 lumen light source. I believe that would rule out LEDs, what about other types, HID, etc?

Comments and advice appreciated!

 

[Paul Baldwin]

Hi wechnivag,
take a look at this thread for info http://www.lumenlab.com/forums/index.php?showtopic=24619

I'm just in the process of trying to improve on my first attempt using an Cree mc-e. It's already watchable in a dark room but I'd like it brighter

Paul.

 

[wechnivag]

Hi Paul,

Thanks for the reply. Did you use the original projector power supply for the original light, or an alternate power supply for the MC-E? Do you have optics in front of the MC-E?

I was thinking an array of Q5s close to the integrator to capture the max amount of light. 16 Q5s at 200 lumens each gives 3200 lumens. But this is still much less than the 10-10k lumens of the original bulb.

Can share some photos? Thanks!

PS: Saw some of the other lumen labs projects. Interesting!
PPS: Found this thread on CPF!! http://www.candlepowerforums.com/vb/showthread.php?t=206771

 

[Paul Baldwin]

Hi,
my first attempt was an mc-e with a 50mm aspheric lense. It was mounted to one of these http://www.ballicom.co.uk/cpu/heatsink--fans/startech-fans-chipsetvideo-card-orb-fan.p281971.html allowing me to keep everything inside the case. I used plumbing fittings to hold the lense. I also used a KD 230v 18w 700mA driver. I removed the original power supply for the lamp, and utilised it's 230v feed and mounted the KD driver in its place.
The current setup uses a 22mm lense mounted directly above the led and a 68mm lense approx 35mm infront of that. It's not permanently fixed yet though. For now I'm using a pc psu and some 10 ohm 10 watt resistors to supply 3.2ish amps. Definately not a long term fix tho as they get very, very hot, as in hot enough to melt paint on windowsills and the side on your light meter box lol!
I bought the mc-e when they first came out, I'm thinking a high bin sst-90 may well worth a try when they are more readily available.
I havent taken any photos as yet, I'll try and sort some out (it's not pretty tho lol!) and I'll have a look at that link now thanks

Paul.

 

[wechnivag]

Wow, nice! How many lumens do you reckon you are getting through the projector? Does the room have to be completely dark to be usable with one MC-E?

Electrodacus seems to be getting a usable picture with only 1-5 lumens (!!). Seems very odd to CPFer who are used to 200+ lumen LEDs, and 20k-50k lux throwing lights..

Sound's like a fun project!!

 

[Paul Baldwin]

Hi,
sadly one of the mc-e dies has gone so I've lost 25% of my light. Ah well I'll just use it for something else and get a brighter one . I think it was my own fault as all the insulation has melted off the resistors and I carried on playing lol.
Things started out roughly like this, with another shorter tube holding the 50mm lense. I found that using the tube to hold the lense actually reduced overall light output.

Things now look more like this, the lense can be locked in place by the small brass nuts I have ripped out of some socket back boxes. The large lens is mounted in an old pc fan shroud, the smaller in a plumbing joint. Extension socket pins with the heads cut off are handy all thread.

It's only showing 9 lux sadly on a 1m screen now

Roughly in place

A particularly dark screen saver

and a brighter one

and a still from Hancock which I watched a couple of evenings back.

The lighter section in the top left corner is light leaked out the projector as the cover is not on.

Paul.

 

[wechnivag]

Wow very nice! Where did you get the 68mm aspheric? Those photos are with a 3 die MC-E? Your lens holders and heatsink are very well done. So much heat from one MC-E?

I'm trying to figure if i should try a 3x3 Q5 WG with ~20mm optics on each one, or an MC-E/P7 with one large optic (like your 68mm lens) = smaller beam angle compared to 20mm optics.

Which setup would be more efficient in capturing and collimating the lumens? 9 Q5 will have about 1800 emitter lumens, but less captured by each 20mm optic, and larger beam angle. MC-E/P7 will have up to 800 emitter lumens, more captured and smaller beam angle due to larger optic diameter.

 

[bshanahan14rulz]

could you do something like evenly backlight a diffuse panel directly behind the lcd and focus the lenses on the lcd? I have no background with image projectors, but might that work?

 

[Paul Baldwin]

Hi bshanahan I honestly don't know the answer to your question as I have no knowledge with image projectors either. This one is the first I've ever owned and it didn't work when I bought it. All I know is it requires a very narrow beam of light to operate properly.
Wechnivag, I got the lense here http://www.dealextreme.com/details.dx/sku.13618 it's ok but not the best as there are some flaws in it but you can't really expect more for the price and it's 66mm btw. Electrodacus has found that his setup is twice as efficient with a single P7 compared to his multi-led one and it's easier to build. I went with the mc-e as opposed to the more powerfull P7 as I thought it would be easier to get a tighter focus.
The heatsink is overkill I admit but I had it lying around. It is also easier to mount and align the larger lense setup than with the smaller but just as effective fan cooler.
Electro estimates mine onscreen at a very lowly 6 lumens at the mo, apparently I should be achieving more like 20 even with only 3 dies!

Paul.

 

[Paul Baldwin]

It's still not very bright for some reason but I've now managed to register 17 lux on a white screen. All I did was clean most of the lenses and mirrors! It appears someone else has attempted this in the past by the fingerprints I found on the lenses. It's an improvement but theres still some more lumens to find yet.

Paul.

 

[Paul Baldwin]

Hi,
I've made some more progress by ditching the small lense and swapping it for the original 50mm aspheric I was using on its own. No matter what I seemed to try I cant seem to get the output to vary at different focal lengths :blink: I get the best output with the first lense touching the led and the second lense touching the first.

I cant get a perfect projection of the dies when using the second lense, I still think a higher quality one would get better results. The 50mm lense gives a crisp image of the dies when on its own.

I've now managed to get 25 lux on screen, a bit of an improvement on the 9 before and I should have 25% more light

There still seems to be quite a lot of dust in the projector nearer the main lense, I may get a can of spray air and see if it makes any more difference? Then decide on which led to replace the mc-e with when funds allow.
It's actually watchable now even with the led wall lights on, although they are best dimmed.

Paul.