Hello all. I will build a pocket sized projector. It is based on a 2.5'' screen (salvaged from an old xbox controller). And an led array for a backlight. My goal is to make this projector as small as possible with the option of battery power. I will be using a lenses from an ohp (not the frensel but the right angle triplet) as my condenser after the lcd and i will be using either a half inch triplet or a 1.5'' salvaged lense to focus my projector.


I will post pictures as soon as possible if requested.

Does any have any words of wisdom?

I have read the "968 led backlight post" & the "projector in pvc tube with 2.5'' lcd'' - any other recomended readings?

thanks


lcd : http://www.ghettohardware.com/articles/mcebathroom/ (rca input)
LEDs: http://cgi.ebay.com/New-Product-100X-5mm-W...1713.m153.l1262

Condenser lens (instead of a frensel) - look bottom right hand corner - will take apart: http://www.bytefixx.com/ebay/sox646.jpg



I have been researching the build of my projector for 2 months. I originally started with a over head projector that i planned to use a 15'' lcd on. Now after stripping the lcd and working back and forth, i have decided that the size of the unit is ridiculous and once the novelty has worn off, i will probably have no use for it. so that brings me to where i am now.

crazychen - Thanks for the reply! You are all over this forum - i saw your group buy page. Awsome community here.

Do you recommend me staying away from the 2.5'' screen due to poor resolution? have you seen this project: http://www.lumenlab.com/forums/index.php?showtopic=4415
http://www.lumenlab.com/forums/uploads/pos...-1114924600.jpg -immage quailty.

- he used a 2.5'' screen and was able to get results. (i am building more for novelty then anything else.)


Why do you recommend me staying away from 5mm leds?

thanks!

Interesting - so it is because of heat that these leds are not good. I did not know they heated up. I didint realize that the cree leds were more efficient, i actually thought they were very in-efficient.

so then how have people produced those led arrays such as in the photos below? http://translate.google.com/translate?u=ht...Flanguage_tools

also why did you recommend against the 2.5'' lcd?

Interesting. Thanks for all the feedback! Thats awsome that you built the led array! What was the mcd rating & angle of the leds you used? 55,000mcd is 2-4x brighter then most other leds. (Cetainly nothing compaired to the cree leds - but still significant. )


I know that no one likes the 2.5'' screens - but i actually have one available - which inspired the revamped build, so i want to try it.

So great news! I just picked up a 175 lumen led from a lantern in walmart. No idea of the viewing angle & no idea how to convert lumen to candella, but i am really excited. My design will change now to incorporate a condenser lense placed between the led and doublefresnel then out to my triplet. -ahh this is too complicated to explain - i will take some pictures and post.

any input with just the info above?

thanks

here is the design. I am trying to use what i have available to me. The first lense is a salvage - and i woant to use it to decrease the necessary distance between fresnel and light source. The fresnel lense is both a condenser and focuser - from an ohp that i will have to cut. the led will be mounted to a computer heat sink.

are there any flaws in my design?

Good that you used the power led the 5 or 10mm are not so good to hard to use the light for a projector.
see myPLOG
I see that you use the optic from an OHP this are heavy an if you need to be portable ....... The fresnel from OHP is big do you want to cut him.
For 2.5" you can use directly a lens not a fresnel.

I DIG THE IDEA OF POCKET PROJECTORS!!!

I'm still researching the potabilities including (but not limited to) 3D passive, short throw lens, slide in filters, usb flash drive input, usb video out, stand alone functionality, laser projection, and whatever else i can dream up. i see all these idea in existing retail products.and now theres some news about putting pico projectors in phones http://www.pcmag.com/article2/0,1895,2080442,00.asp

anyway, here is a site I've been drooling over
http://www.tekgear.com/index.cfm?pageID=1

very interesting mini-projector
Tanks for the links