Wednesday, May 19, 2010

Make A Simple Overhead Projector

Make a simple projector by mounting an LCD screen on top of an overhead projector.


You can make a simple LCD overhead projector from readily available parts to enjoy the big-screen experience at home. Building an LCD overhead projector entails mounting a stripped LCD screen on top of a standard overhead projector. This allows the setup to project the images on the LCD screen on a wall, similar to how transparencies are projected. Although a homemade projector may lack many of the advanced features or options of a branded projector, building a projector at home will be considerably cheaper than buying one. Before you begin, make sure the LCD screen and the projector's bed -- the light window -- are the same size. If you have either one of the two devices (the projector or the LCD screen), obtain the other according to the size of the device you already have.


Instructions


1. Disassemble the LCD screen. The process will depend on whether you are taking apart an old laptop computer or a desktop monitor you no longer use. If it is a laptop, remove the screen bezel by undoing screws from the frame holding the screen. For a desktop monitor, remove the back casing first.


2. Disconnect the power and video cables from the screen. The LCD screen is attached to cables that have to be undone before the screen can be pulled out. Locate the connecting ports on the screen and gently pull out the cables, taking care not to break the plastic assembly at the end of the cables. You may have to maneuver or unclip the cables.


3. Remove the screen. Once the screen bezel or plastic casing is removed, and the cables are unplugged, you can dismount the bare screen by pulling it out. Hold the screen from the edges and carefully remove it from its shell. The inverter board --- a rectangular green component --- will be attached to the base of the screen. Rest the screen face down on a cushion.


4. Install insulating spacers on the edges of the projector's light window. This will prevent heat from the light window from damaging the LCD screen when you lay the screen on top. Place the insulating foam pads on either side of the light window, and tape them to the sides of the projector to hold them in place.


5. Lay the LCD screen on top of the light window. Align the edges of the screen to the projector's window and carefully lower it onto the foam pads. The distance between the light window and the LCD panel should be at least 8 mm, when the screen is placed over the pads. Next, reconnect the power and video cables. Plug in the cables to the appropriate connecting ports on the screen and inverter board.


6. Install the cooling fan. Tape the plastic assembly around the fan to the side of the projector so that its air flow is directed toward the small gap between the LCD screen and the light window. Installing the cooling fan properly is critical because if it is not mounted properly, the heat generated by the light window would not be removed and could damage the screen.


7. Plug in the power cord from the cooling fan to a wall outlet, and connect the LCD screen to a video source, such as a computer or a DVD player through the XGA port. Start video playback.







Tags: light window, overhead projector, connecting ports, connecting ports screen, desktop monitor, foam pads