Cheap Improved LCD Overhead Projector

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Posted in WorkshopHome-theater

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
http://blog.wdka.nl/make

Step 1: Parts, Tools & Links

SHOPPINGLIST

# 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 Marktplaats.nl 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.

TOOLS

# Screwdrivers
# Solder iron
# Iron saw
# Glue

HELPFUL LINKS

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

# Information about overhead projectors:
- http://louisville.edu/~wchall01/diyprojector/overheads.htm

# Information about LCD screens
- http://www.lumenlab.com/forums/index.php?showtopic=4
- http://baseportal.com/cgi-bin/baseportal.pl?htx=/Lumenlab/main&localparams=1
- http://www.dity.nl/forum/schermen/324-tft-ffc-issue-lijst-en-overige-info.html
- http://ecrans.energie-libre.net/

# Other overhead projector projects:
- http://www.neoweb.nl/tftbeamer/index.html (Dutch)
- https://www.instructables.com/id/LCD-Overhead-Projector/

# Communities
- http://www.dity.nl/forum/ (Dutch)
- http://gathering.tweakers.net/forum/list_messages/1091930 (Dutch)
- http://www.lumenlab.com/forums/

# Shops
- http://www.diy-beamer.com/EN/store/comersus_listCategories.asp
- https://secure.lumenlab.com/estore/home.php?cat=252
- http://www.gadaffy.ch.vu/

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!

Links:
- 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 :)

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    131 Comments

    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.

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

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

    Ok after a headache trying to find a cheap filter online. Success http://www.stagelightingstore.com/Rosco-Permacolor-2x2-Square-38000-IR-UV-Filter.html

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

    4 replies

    for anyone else with this question, check alibaba: http://www.alibaba.com/trade/search?SearchText=ir+uv+filter&Country=&IndexArea=product_en&fsb=y

    same problem. Anyone have an answer?

    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

    Also, found this site:

    http://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=897

    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...

    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.

    1 reply

    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.

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

    2 replies

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

    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.

    just the lcd matrix? no..

    hi.
    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?

    1 reply

    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.

    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.

    1 reply

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