How to make a small DIY LED Projector

Step 6 Measurements

Well Done! if you got this far let me tell you something... U CAN DO IT!

This step is very important, now u have to try to get the LED (with it's heatsink), the condensor lens, the fresnel lens, the LCD and the slide projector lens, in line. Pay good atention to the center of everything. and play with the distances between them until you happy with the output.

Once u have the distances 1, 2, 3 and 4 u can calculate the size of the box you'll be looking for.

To calculate the distance 4, try to project the screen size you want. And if u have enuf space it'll be nice if you can retract the lens all the way in without touching the LCD.

Note: Don't worry if u don't have the LCD connected and working, u don't need it working for this step as u will be able to see the dots of the screen in the projected image. Just make sure when fiting the LCD, that the image it shown upsidedown, so the projected image will be straight. what i usualy do is write on the LCD a word (like "hello") when u have it working. that way you make sure the LCD is in the right position without having to connect it all the time to make sure it's right. Just write with something u can erase later.

Note 2: If you're taking a bit of time to do this, have the fan working to avoid overheating the LED.

Comments

[10fellowsd]

you can get loads of condenser lenses at ebay

[supreme-ette]

could i get those from a disassembling a flashlight?

[10fellowsd]

no, flash lights dont have condenser lenses in them

[supreme-ette]

where do i get them?

[Daniel Deacon]

Hey, can the condenser lens be on the LED or does it have to be away from the LED also how would i mount it? thanks! :)

[Daniel Deacon]

Hello im really keen on this project well done and thanks for shareing i am going to buy LM350 and two 0.33 ohm resistors. however i dont know what lens i should buy can i get like a JML frenell lens that goes in your wallet? the LCD i have bought is on ebay it is a 12volt mp4 player 1.8 inch screen. i dont know what to do with the condenser lens i have seen http://www.dealextreme.com/details.dx/sku.13618 will that work. thanks for your pations! :)

[soaringchicken]

Hi newtonn, I am thinking of getting a 3.5 inch lcd is this possible? Do you know of any projector lenses that will work? Thanks

[newtonn2]

You could use it but, the box will be bigger, and the lens you need to look 4 will be a lot bigger too. You could use a OHP lens.

[jrpm1116]

WHAT YEAR AND MODEL BMW IS THE CONDENSER LENS FROM

[exilaus]

if you need a condener lens visit www.dealextreme.com in flashlight diy..i find on this site right diameter condenser lens for my project for very nice cost.

you need only wait....

newtonn2 for your battery external battery pack thinking on use of 18650 lithium cell (4.2v for 2.5mha)
 18650 lithium cell fin inside a battery of notebook or buy charge and battery on previous site.
nice job

i start my instructables i find 1.8" composite monitor 533x244 of resolution :)

[showup]

Can U post a link for the 1.8" composite monitor 533x244 of resolution that you are talking about? Does it have AV input too? Thanks.

[exilaus]

sharonind.com/LCD/LCD018/LCD018.htm  lcd 1.8 only videocomposite input.

[showup]

Thanks for your reply. I am aware of this one from ebay. I had a doubt because the resolutions are different (558x234 vs 533x244).  Thanks.

[showup]

Unlike many of us think this LCD is not a very high resolution one.  The 558 mentioned in this document indicate the number of dotes not the number of pixels. So, if we take each one for RGB 558/3 = 186 pixels horizontal. I just thought it may be useful to some one.

[newtonn2]

 Thank you for explain that, its good to know.

[exilaus]

sorry i wrong size dimension is 558x234

showup,i bought from it .

from document:
number of dots 558(H) X RGB X234 (V)  DOT

for line si  558 X 3  DOT and when you project you see it!!
because you see same this picture on wall .
resolution of this display are same digital camera back screen.
 
i stop my project because have some problem :(
but i think restart it .

[newtonn2]

Thank you for the tip.

All the cells I found inside a notebook battery are 3.7v.  It's a good idea. I used some of those cells to power some LED's You can see here.

Did you finish the projector?

[exilaus]

in finish .... need find good small frensel lens (my is too much opacue ) 45mm x 45mm

This now my tests :

http://picasaweb.google.com/lh/photo/snxoRQRKVKIrTF5NUf5etg?feat=directlink (ssc p4 at 850ma light sorce module)

http://picasaweb.google.com/lh/photo/hX_sgu4YDHUCuarITAQcfw?feat=directlink (in use lcd and 30° optics on ssc , in a shady day)

[newtonn2]

 I got not idea, is one of those that has 4 circular light at the front. There is a picture of the back of the headlight in the instructable. But you can find many condenser lens in other cars headlights.

[sreenvas]

shall I use KB2 photo enlarger condencers of 4" diameter and 3.5 lenses assembly for the projecter

[newtonn2]

 
Could you please send a picture or something? I don't really know what is a KB2 photo enlarger.

[gazoutg]

hello, I'm thinking of making my first projector project,
I tend to do a larger projector based on the infos on this project (the other one you posted seem too hard for me to understand and if i get it right I'll need to get a projector light wich cost hundreds (I cant find an ohp)

What I currently have is an emerson LCD-0700E LCD extra screen.
(http://www.propertyroom.com/itemdetails.aspx?l=5973700)

I was wondering if i could use parts of an old PJ768 Projecta scope I got when i was was 15 years old.(http://www.amazon.com/Project-A-Scope%C2%AE-Image-Projector/dp/B000RSKZ8C)

There is a small mirror inside About 2 inche by 2 inches inside
and a small lense.
Honestly I think my screen will be too large to use theses as parts.

Id like to have an expert opinion :P

Thanks

[newtonn2]

 
Hi there!

 For the size of you LCD, I really would go for the OHP project. 
I used the OHP because it's really easy to find them here and really cheap. 

You don't need to buy a projector light, you could use metal halide, they works very good, they last 100 times more than a conventional ohp light and they are a lot whiter.

I'm not sure about the mirror and lens, maybe once you have you LCD ready and the light source, you could try them to see if they work with your setting.

[gazoutg]

Thanks for the answer.

I see on this site that they sell a ballast to power the light.
Do you know if it's required?
As far as I know ballast are used to reduce intensity and thats bad in a projector ain't it?

Thanks again

[newtonn2]

All the DIY projectors that I've seen using that type of lamp uses the ballast. I also have an OHP witch uses the same type of lamp and is fitted with a ballast. 
But in the link you send me there is a Electronic Ballast, they are really expensive, you could use a normal ballast, there are more heavy and get hotter, but they are a lot cheaper. 

[jrpm1116]

I CANT FIGURE OUT THE RESOLUTION  OF THE TV . WHAT RESOLUTION WOULD U RECOMEND FOR A GOOD SCREEN AND WHAT IS THE MP4 U HAVE THAT HAS AV INPUTS

[newtonn2]

 That really depends on the size of the screen you want to project.

The one I'm using is not too good. It's really difficult to find a LCD that small with a lot of resolution. so... go ahead and use that TV you could always update later if you find something better.

[jrpm1116]

OK THANKS

[jrpm1116]

I FOUND A LENS LABELED 1:2,8/85 WILL THIS WORK ALSO WILL A SCREEN FROM A 2" PORTABLE TV WORK FOR THIS PROJECT

[newtonn2]

 The lens is perfect for a 2" screen, but maybe the tv wont have good quality? How many pixels does it has?

[taz3000nice]

If i only put the fresnel lens and not the condenser what  gonna happen ?

[newtonn2]

 There will be less light efficiency.

[sudhir.swarnkar]

Hi,

That's really cool. I have trouble finding all the lenses. Are all the lenses necessary? If all of them are necessary where did you get them from.

Will it do for fresnel lens
http://cgi.ebay.com/12x6%22-Recessed-Light-Fresnel-Shower-Baffle-6%22-Can.IN6F_W0QQitemZ260474375512QQcmdZViewItemQQimsxZ20090909?IMSfp=TL090909176001r5248

How about slide projector lense? Where did you get it from?

I was also wondering about mp4 player video input. Can you connect your laptop to it or can you only play videos stored on the memory of mp4 player?

[newtonn2]

Hi! I'm glad you like my instructable.
I did need all the lenses, but you could try without the condenser and see how it looks.

The condenser lens came from a headlamp of an old BMW.
The fresnel lens you show in the link I don't think will works.
The one i'm using is just a magnified fresnel lens like this one http://cgi.ebay.co.uk/XL-Magnifier-Fresnel-Lens-Full-Page-Magnifying-Sheet_W0QQitemZ160360480021QQcmdZViewItemQQptZLH_DefaultDomain_3?hash=item25563abd15&_trksid=p3286.c0.m14#ht_2006wt_1000

but i mine is hard, i don't know about that one.

The slide projector lens it's ok if you're using a LCD not bigger than 2.5"
I got it from a boot sale.
My mp4 has a AV in connector, so i can connect it to anything, but the pixels are not enuf to use it with a computer.

[19charbel96]

why to use FRESNEL LENS? can i not use it?

[newtonn2]

The fresnel lens helps to distribute the light evenly in the lcd, so you don have some parts of the projector image brighter than other.

[oli1122]

because it condenses the picture in to the correct format to be projected through a lens. without it you will probably end up with only parts of the picture being projected. but they dont cost much and you can always get a small pocket page magnafyer. I used a cheep JML one

[chenek2001]

HI! Can you tell me, why is better to use this kind of focal length 85-100mm?

[newtonn2]

it's because you will see a bigger screen. ej 85mm lens will give you a projected screen of about 2m diagonal if you use a 2.5" screen from 4 meter away. if you have a lens 200mm will be about 1m.

[chenek2001]

Fantastic! I'm going to start a project like yours soon. Thanks for your reply and your instructable!! :-D