# 365nm UV LED and DLP projector DMD chip life



## elite641 (Jun 28, 2013)

Hello everyone,

Working on a personal Lithography project, have plans to replace the LEDs of a Pico projector with an equivalent power 365nm LED. Actually I am divided between resin and curing light, the resin I could find seems to like shorter wavelength UV, cures well in 30sec under a 6watt nail polish curing lamp, but very poor under bright projector light (with color wheel and UV filter removed).

I am planning to try a 3W 365nm LED, the thing that is puzzling me if the 365nm UV light is going to damage the DMD chip quickly? 

I am new to the forum, if this is already discussed somewhere, help me out!

Cheers!


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## DIWdiver (Jun 28, 2013)

Sorry, that question is above MY pay grade!


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## mash.m (Jul 3, 2013)

why should uv light demage the dmd chip? its a mirror device so all light will reflected to the outside lenses. the ir is blocked cause thermal problems on the chip...

markus


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## bshanahan14rulz (Jul 3, 2013)

Don't forget to look into the UV transmissivity of the lenses used in your optical system, if you choose to reuse the projection optics. 

http://focus.ti.com/pdfs/dlpdmd/Digital_Projection_of_UV_Light_is_Enabling_New_Markets1.pdf < interesting read, but page 6 may have more info that might interest you.


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## MOGhouse (Jul 27, 2013)

Hi - also new here, and have also looked into converting a LED pico projector to UV.

Texas Instruments makes 2 versions of the DMD, one specially for UV and SILLY expensive, however the standard will work with over 400nm .... however TI also says that lots of 400mn UV will reduce lifetime and over time result in "stuck" pixels. The reason for this is supposed to that lots of UV will out-gas the lubrication used in the DMD. My best guess is the DMD will last quite long if you use 400nm

I do not believe the optics have UV filter in LED projectors - as they do not produce any UV at all (unlike bulb projectors), blue is produced typically around 470nm. Also the window on the DMD will let 400nm pass.
However, pico light engines use dialethic mirrors to produce red blue and green. Depending how the light engine is arranges and which colour you plan to replace - these mirrors may have to be removed - no big deal.

The replacement UV LED should be placed VERY close to the original position and size of the emitter - otherwise you will have problems with culmination of the light beam. 

I am trying to convert a Dell M110 (or Acer K130 which is the same) but have not yet found a good UV LED candidate to replace the blue (as I would want to do).
Please post if you find any good UV LEDS - thanks


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