Introduction: Cheap Improved LCD Overhead Projector

This is an other Instructable about how to build your own cheap LCD projector, but with some improvements.

More information about this project here, here and here

The Make Class
Willem de Kooning Academy Rotterdam

Step 1: Parts, Tools & Links


# Overhead projector - 20~50 Euro
One of the main parts is a overhead projector. You can find these things at schools, secondhand shops and websites like or eBay.

Tips for buying:
1) Look for an brand projector, like 3M
2) Choose one with a high wattage lamp. I used a 250watt lamp, thats in daylight a bit weak, you can better look for an 400watt lamp.
3) A bigger glass plate can hold bigger LCD screens
4) Check the glass plate on damages

# LCD monitor - 25~50 Euro
The second main part is a LCD screen. I used a TFT computer monitor. There are a lot of screen sizes. Look for one that fits on the glass plate of your overhead projector. Bigger works too, but then you will lose some screen edges.

A lot of screens got a short FFC cable, thats called a 'FFC issue'. You need to extend the cable by replace it with a longer cable or extend the FFC cable with a solder iron. The easiest way is to find a screen with no FFC issues.

Tips for buying:
1) Search for one that fits on you overhead projector.
2) TFT computer screens are the easiest way. Laptop screens needs a controller, they are hard to find in Europe.
3) Look for screens with a broken backlight. You don't need that component for this projector.
4) Search on the internet for a type with no FFC issues. You can look in the database of Lumenlab or search with Google "LCD brand + model + ffc issue"

# Wood - 2~5 Euro
For making a frame that will hold the LCD screen.

# FFC cable - 15 Dollar
Only if you have a screen with a FFC issue. You can buy this one at the Lumenlab Store.

# UV & IR filter - 20 Euro
This will help cooling down the screen and prevents the screen is getting yellow.

# 2x Cooling fans - 10 Euro
These will help to keep the LCD screen cool. Simple computer fans, you can get these from old computers or buy it at a local computer shop.

# Gaffer tape - 10 Euro
This tape could be used for screen protection at the wooden frame.

# Aluminum foil - 1 Euro
To improve the light reflection.


# Screwdrivers
# Solder iron
# Iron saw
# Glue


Please read before you start a lot of information about building a projector. It prevents a lot of problems.

# Information about overhead projectors:

# Information about LCD screens

# Other overhead projector projects:
- (Dutch)

# Communities
- (Dutch)
- (Dutch)

# Shops

Step 2: Stripping the LCD Screen

Start stripping the LCD screen. There are a lot of different screens, it could have different parts and and look not exactly the same. I describing here the basic steps.

Tips before you start:
- Make pictures to remind
- Watch out and be carefully

1) Disconnect all cables and wait a few minutes.
2) Put a towel or pillow on your desk for protecting the LCD screen from scratches.
3) Remove all screws, usually you can find these only at the back.
4) Lay down the screen on the towel on your desk and remove first the back cover and then the front cover.
5) You will have now something like this:
6) Disconnect all cables and remove the tape if needed. Do this with your hand and not with tools. It's very fragile.
7) Use a screwdriver to remove the power supply, the lcd controller and the OSD controller.
8) Remove the tiny screws from each side.
9) Remove carefully the plastic from the print, watch out for the brown plastic wires. If you damage this, your screen is dead.
10) Now you can remove safely the frame. (it's a 'click' system)
11) Wipe the LCD screen carefully out the white backlight plate.
12) Finished!

- An other guide for Dutch readers

Step 3: Testing

Now we can test the screen on the overhead projector.

1) Lay down the screen on the overhead projector. Use something between the LCD screen and the glass plate to create some space. Watch out for scratches on the screen.
2) Connect the screen to the power supply, LCD controller and OSD controller.
3) Connect the LCD controller to your computer.
4) Turn it all on to test it.

Do this only a few minutes !!! Otherwise the screen gets very hot and will die !!!

Step 4: Making the Frame

Because all overhead projectors and screens got different sizes are there many ways to make a frame. I'll give here some tips:

1) Important is the cooling of the screen. Create enough space between the LCD screen and the glass plate (between 6-8cm). In my design I placed at the left and right side a 80x80mm cooling fan. To create a good airflow, one will blow in and the other blow out.
2) Make the screen hole in the middle.
3) Think about where you can place the power supply, LCD controller and OSD controller.
4) Paint it a nice color.
5) To improve the light reflection place some aluminum foil inside.
6) I placed some gaffer tape on the edges of the screen hole to protect the LCD screen.
7) Place the cooling fans on the frame and connect these wires together.

Step 5: The IR+UV Filter

To protect the LCD screen you'll need a IR (against heat) + UV (against fade) filter. You can buy these separately or an all in one glass. I've used the all in one. It's a small glass that needs to be placed a few centimeters above the lamp.

The easiest way to create a frame that will hold the glass above the lamp. Use iron or aluminum to make the frame. Don't use plastic or wood, because the frame gets very hot!

Open your overhead projector to look what the best way is to fit a frame above the lamp.

I've used a part from an old ATX computer power supply and made with a iron saw a hole for the filter.

Step 6: Building the Projector

Everything is now finished to build your projector.

1) Open the overhead projector to place the IR+UV filter with frame above the lamp.
2) Clean the glass plate.
3) Place the wooden frame at the projector.
4) Place the LCD screen on the frame.
5) Place the power supply, LCD controller and OSD controller on the frame.
6) Connect these to the screen.
7) Connect the wires from the cooling fans to the power supply. Do this only if there is a 12volt connector on it. Otherwise you need a universal 12volt adapter.
8) Connect the LCD controller to a computer.
9) You're done! The projector is finished.

Step 7: End Result

See the pictures below :)


london made it!(author)2015-07-22

Late in the game, I know, but anyone still having this issue. I looked everywhere and finally gave up searching online for this thing. It doesn't exist cheaply. However, I found a solution. Hardware stores sell low-E glass/film for like $40/roll. Also just fyi, water will absorb IR and UV.

AdilR2 made it!(author)2015-07-16

Pacon Overhead Projector Caddy, 12"X7.5" Each Side, Blue can i use this one

vushan made it!(author)2013-11-24

what kind of light is it? can i use cfl high power i actualy need the freshnel lens , what will happen when without freshnel lens projector runs ? (y)

jokakid made it!(author)2011-12-31

Ok after a headache trying to find a cheap filter online. Success

DaMachk made it!(author)2010-10-12

Can't find any UV & IR filters... any chance you have an store/dealer?

mrkobayashi made it!(author)2011-12-22

for anyone else with this question, check alibaba:

tten+eyck made it!(author)2011-10-04

same problem. Anyone have an answer?

mattadamsnet made it!(author)2011-12-21

google "hot mirror" the 0 degree one is more like the glass you see above.

There are IR, UV and IR/UV hot mirrors, a 2" square is somewhere around $40

mattadamsnet made it!(author)2011-12-21

Also, found this site:

AKA+the+A made it!(author)2011-12-21

If you search for "LVDS" on ebay, you'll find a shop that sells LCD panel controllers (they have cables as well!) at an unbeatable price, for $25 you can get a controller suitable for most LCDs up to 19'', it even has 2 inputs - analog VGA & DVI...
The more expensive ones can include a composite input &/or a TV tuner...

liammk made it!(author)2010-07-24

How many fans would i need to replicate the function of the ir/uv filter. I was thinking 3 blowing in 3 blowing out for smooth air flow.

mattadamsnet made it!(author)2011-12-20

I know I'm replying more than a year later, for for anyone else who stumbles upon this.... The filter is to remove the IR and UV wavelengths from the light, no amount of breeze can do this...

And the filter is to mainly protect the LCD.

Exiumind made it!(author)2011-10-14

image looks kind of dead to me.. any way to enhance it? maybe the contrast or brightness of the lcd matrix itself?

afunkle made it!(author)2011-12-06

the only area you will want light to come out of is the main lense area/mirror top.

afunkle made it!(author)2011-12-06

im posting up top as a reply, you should improve image quality of these projectors by building a cardboard box over the top of the projection unit. light bleed out into the room from the main projector unit itself is probably causing the image to look faded. obviously leave a hole where the glass mirror is so the projector image will go through the box. you may have to monitor for heat, you will want to make the room light tight as possible, even if you have to put a blanket over the window at night and cover clock radio led's etc. because even a small bit of light will wash out the projector image. make sure you monitor for heat when you put the cardboard box over the unit and watch for heat dammage as this is untested, you may have to put small fans in the unit to blow out hot air if thats the case. hope this helps, i experimented with a non projector and simple cardboard box and mirror and lense and got ok results along time ago. havent had the funds to try a projector modification.

Exiumind made it!(author)2011-10-14

just the lcd matrix? no..

Olga_16 made it!(author)2010-12-14

We just finished our DIY-projector until this step. Everthing works, but the light is really bad. We have an OH-projector with quite a decent lamp so it seems strange. Someone who can support us?

bwrussell made it!(author)2011-04-01

Here's a couple things to check.
1. Make sure everything is clean. The bulb, the mirror (if your OH uses one), the glass pane, the screen, and the lenses and mirrors in the focus unit.
2. Make sure there aren't any of the clear or (especially) opaque plastic sheets on the LCD panel. These were there originally to help diffuse and spread the light from the backlights but they cut down on the amount of light that makes it through the screen.
3. Play with the display controls on the OSD controller. (Brightness, contrast etc.)
4. Leaking light. Make sure you aren't letting any light out of the edges of the screen. Also make sure the room you are projecting in is dark.

If none of that improves the brightness you could try a new bulb or wiring a second bulb.

animefanatic made it!(author)2008-08-10

Is it at all possible to use an old CRT monitor instead of lcd for something like this? I have 3 CRT's just sitting around and need to do something with them.

porksmash made it!(author)2008-09-02

No, CRTs work very differently and can't be used like an LCD screen. Check em out on Wikipedia and you can see why.

slimguy379 made it!(author)2008-12-25

hence my 12 gauge theory... make them useful

rrrmanion made it!(author)2010-10-31

add to the fun: hook them up to a computer displaying an image of someone you don't like

slimguy379 made it!(author)2008-10-05

take a 12 gauge, to them i rarely use crts anymore and doubt anybody would like to buy them/ take them

tomtortoise made it!(author)2010-10-25

so i got a screen and unlike you my power supply is the middle of the base and screen in the arm thing and so i opened it and i see a HUGE transformer and a MOFING BIG capacitor so i wanted to make this a small portable ish screen but idk how or what i can put the power supply into. or if i can use a wall wart please tell me how

GreenD made it!(author)2010-10-10

Is it possible to use an LCD that has no power supply or controller ? Mine came from a lap top, thus its power supply and controller were left in the lap top (I don't have the lap top)

Pondering+It+All made it!(author)2010-10-01

Light coming from multiple directions (like from an LED array or a CFL ends up projecting each LCD pixel to multiple points on the screen. The result is a blurry image. There is a basic law of optics (conservation of etendue) that says you can't overcome that with lenses, reflectors, etc. This is the reason all types of commercial projectors use lamps that have a very small, very bright, single point source. You can use halogen bulbs (like most overhead projectors), a DIY carbon arc (VERY messy and dangerous!), or a metal halide HID lamp. A 250 watt MH lamp gives a very nice image, but 400 watt is much brighter for a large (EG. 100") image. You could get by with less if you can make the room totally dark, project a smaller image, squint,etc. A single super-bright white LED could be used but compare its lumen rating to the MH lamps (13,000 - 20,000!): You will get a very dim or very small image. BTW: It is an urban myth that LEDs are "super efficient". They are not much better than a halogen bulb, and much less efficient than metal halide.
A piece of clear polycarbonate (from Home Depot or Lowes) makes a very good UV filter, which you will need if you go with a MH lamp. You can buy heat filter (IR filter) from places like BH Photo for a reasonable price.

studnt made it!(author)2010-08-15

Im very much concerned about LCD display and the heat which can completly distroy the lcd.I've got a OHP but its projecting yellow light :( Is there any thing i can do to obtain a white light?Why can't we use CFL bulbs for the Project. I found out that 13w one has at least 840 lumens.Will 23w CFL do the job?. or can i use 2 of these 13w bulbs.Also they don't heat up very much(also have long lifetime).Im thinking if the light can be concentrated by using a reflector it might be fit in to the OHP by doing nessasory alternation to the OHP.plz help meout guys. Hoping a positive reply. By the way instructables rocks {:{)@=

kolokoydog made it!(author)2008-08-21

can the projector bulb be remove since it only generates heat not the brightness or improvement of the quality of the picture of the lcd?

1337chaos made it!(author)2008-08-26

you dont understand how overhead projectors, or LCD's work. let me put it simply: an LCD screen itself is a thin piece of almost glass-like material, behind that is a backlight. without the backlight, you cant see the screen. the backlight pushes its light THROUGH the LCD screen, and into your eyes. without the backlight, the screen just looks black. a overhead projector uses its lamp as a backlight. which is why you use clear pieces of paper to write on. the light goes through the paper, into the mirror, and onto the wall. in this project, he's using the LCD screen itself, with the backlight removed (if the backlight was still attached to the LCD, it wouldnt work, because the lamp from the projector cant go through metal ;) he's using the lamp from the projector as a replacement backlight, which is about 30x stronger than the LCD's original backlight. the projector lamp supplies enough light that it can project it onto a wall in a not-overly-dark room. otherwise you'd just be... well... it would be like taking a monitor, putting it in front of a mirror, and trying to watch the reflected screen on your wall, and it wouldnt be bright at all... hope this answered your question!

kolokoydog made it!(author)2008-09-08

well couldnt u just max out the brightness n contrast of ur lcd to make a good pic out of the projector?

rujoesmith made it!(author)2009-01-22

how are you going to max out the brightness with no backlight?

vonFelsenheim made it!(author)2010-06-25

I think the question was something like: can you leave the monitor intact with the brightness turned up and just project the image with the OHP turned off? The OHP lamp is a heck of a lot brighter than an LCD monitor, of course. But even in a nice dark room, you need the OHP's fresnel to collimate the light so it will project without blurring. Interesting. Could you remove the frensel, place it in a frame OVER your intact LCD and have that project? Time for experiments, I think.

1337chaos made it!(author)2010-06-25

It's not going to project unless you have a lamp large enough to actually project the image. Placing a fresnel lens in front of a monitor will do nothing but make the image look larger than the monitor is. It's the same concept that's used in DLP and older bigscreen tv's. It's nothing more than a reverse OHP. It uses the OHP glass lens and mirror on the inside, and the fresnel as the screen.

linkaylomen made it!(author)2009-02-12

I think you really need to learn how an OHP works before you could start this project, its very simple and easy to understand how they work and why.

OHPs are very basic in design so I trust you will understand this article:

I know Wiki isn't concrete for info but this article is good for the intended purpose.

bwpatton1 made it!(author)2009-01-23

a good way to demonstrate a back-light is take a laptop, find the small button at the top right or left of the keyboard (all the way up almost to the screen) and push it down. this will make the screen go "black". thus demonstrating a screen without a backlight

jordster1998 made it!(author)2010-06-11

how much in total would it cost to build this projector

locumdoctor made it!(author)2010-04-25

Yes you can plug any games console to a projector as long as you have the relevant cables.

Gizmotech made it!(author)2010-01-15

The halogen lamps last about 100 hours which is poor. You can convert the OHP using a ballast and UHP/SHP burner which will last about 4000 hours. Parts are available at if anyones interested.

locumdoctor made it!(author)2010-04-25

which bulb do I need for a Infocus LP70+?

eviltaco13 made it!(author)2010-03-21

 is there a way to like plug your xbox 360 into the projector?

streetsign made it!(author)2010-04-11

 ya they sell a vga cord the xbox 360 at game stop, just search vga at

soyviejodeme made it!(author)2010-03-27

 I found that the screen stays much cooler if you place it directly on top of the glass plate, instead of leaving a space of 1-2 cm. I think this is because the fresnel lens focuses the light towards the mirror and consequently the higher you place the screen, the more light and heat concentrates on it (if you try it with your hand you'll see that the further away you get from the glass plate, the hotter it gets)

And with this set-up you also don't need a fan to keep it cool, in my case much cooler than with the spacing and fan.

eviltaco13 made it!(author)2010-03-21

 nevermind i just realized that this is a overhead projector haha

floryzzz made it!(author)2010-03-03

Dit is pas de 2de keer dat ik ene nederlander hier zie
mooi gemaakt 

Gazatteer made it!(author)2010-02-16

Is anybody there to answer my questions in my previous comment?

pyromaniaman made it!(author)2010-02-21

 It looks like he's used a monitor with a built in power supply, in the first picture you can see the first board (for video processing) with a VGA input and a second board, with a kettle lead style input for the power supply.

Gazatteer made it!(author)2010-02-12


Looks like a standard fan that you get with most computers.

What power supply did you connect to? Does the power comes from the LCD display or the mains? Could you perhaps show me a photo?

Where did you place the powersupply for the lcd? Difficult to track in the photos.

I have peeled ;) the lcd monitor. Yes, successfully. Tested the lcd on the projector and it works.

I now need to make a frame and get a blackout cloth for the screen.


tokooloshe made it!(author)2010-02-06

Would it be possible to replace the bulb inside the overhead with several energy saving light bulbs? That would certainly solve the heat issue. Would you still need the UV filter?

porra made it!(author)2010-02-04
porra made it!(author)2010-02-04

Hi, attempting this instructable, could you possibly elaberate on the
"UV & IR filter" and where to find one, i live in Cape Town, South Africa.

Thanks in Advance

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