Would this diagram of a projector be right?

Question

http://www.geocities.com/jim_bockmon/PROJECTOR.jpg if not could you make your own and email it to me at [e-mail] or exaplain whats wrong and say what improvements it would need

Answer 1

Your LCD projector diagram is incorrect. Here's a diagram which correctly displays the LCD setup:

http://www.projectorpeople.com/resources/images/lcdbig.gif

Good luck!

Answer 2

Actually, your design could work with the proper LCD imager and LED lamps. The LCD imager would have to have built-in color filters such as are used in direct-view LCD displays. The LEDs need to be white LEDs or a mixture of red, blue and green LEDs to produce white light. The only item missing from your design is a diffuser (such as a ground-glass piece) behind the LCD panel.

The main problem is that you would have to use a large LCD panel in order to get enough pixels, since you need three LCD cells (under red, blue and green filters) for each image pixel. You also need super-bright LEDs. It's difficult, but not impossible.

Also, your lens would not be just a simple convex lens; you would get very poor image quality. You must use a multi-element lens of the proper focal length. If you use a lens of fixed focal length, there will be only one position of the projector that will give an image to fit the screen. To determine the focal length you need, use the formula

1/f = 1/s + 1/d

where s is the distance to the screen and d is the distance from the lens to the LCD panel. The image size on the screen will be approx s/d times the imager size.

Answer 3

Uh.... NO....