here is some guide for you
STEP 1
Consideration choosing the right LCD for your need.
A> LCD size
DIY projector normally is bigger , or alot of times, alot bigger than commercial projector. Size normally is the first issue.
1. If size is not an issue, then there are alot of cheap used LCD out there with digonal size of 15 inches with xga resolution, very good enough to project high definition images.
2. If size is a problem, then its gonna take alot of effort to get compatible LCD. But if you have the money to spend, you can easily buy on line. Smaller LCD like 8.4 inch diagonal normally has SVGA resolution, few are xga resolution which are very expensive say around $250 on line.
In the pics below, the black box is the box for my 8.4 inch lcd and the bigger one is the box for my 15ich lcd. Beside them is the chair for comparison. Those boxes, I believe can still be made smaller by 30-50% based on your design.
B> LCD resolution
1. XGA Resolution (1024x768 pixel) A bigger LCD say 15 inches and above has xga resoluiton which are capable enough to display high definition images. Smaller LCD with XGA resolution are expensive.
2. SVGA resolution (800x600 pixels) - DVD disk has a resolution of 720x480 pixels so if you have an lcd with svga resolution, it can display the full resolution of dvd players which can display very good images (xga of course is alot better)
3. VGA resolution (640x480) - If you are really low on budget, some small lcd has vga resolution. this can still project good images though your projected image size will be limited otherwise you will see screendoor effect(pixelated) and washout images.
It is not recommended anymore to use lcd with resolution lower than vga resolution.
C> LCD inputs
1. VGA input - Never buy the lcd without vga input (computer video cable) . VGA input can display progressive output from your sources like pc and component output ( need transcoder to convert to vga) of dvd player .
2. HDMI/DVI (digital input) - Some lcd models have DVI input which is very good because some dvd players have dvi output. Very few lcd have HDMI input. DVI/HDMI peforms better than vga interface because it will bypass the A/D converter from dvd players, pc, and lcd monitor. The lesser electronics used, the better is the image quality.
Composite input/ s-video of dvd players only displays 720x240 pixels so avoid using this as much as possible. Remember VGA interface is the minimum requirements.
D> LCD aspect ratio
1. 4:3 aspect ratio- It has the same aspect ratio of regular TV. In the old days, most of the movies are 4:3 so no problem in displaying the correct image size. But nowadays, most movies are widescreen (1.77:1)or letterbox format ( 2.35:1). So you will see black bars in top and bottom of your image. You will lose up to 60% of lcd resolution when you use widescreen and letterbox movies so image quality will go down.
2. 16:9 aspect ratio- When you play 4:3 aspect ratio movie, you will see black bars at the two sides. But nowadays, widescreen are prevalent and you will use full resolution of your lcd and image quality will be better than when using 4:3 aspect ratio lcd.
E> Contrast Ratio - This is other lcd specification that can make lcd cheap or expensive ( the other one is resolution). Higher contrast say more than 1000 can produce beautiful images than with lcd with lower resoltuion. Contrast is the difference in intensity of white and black.
F> Response time- Lower lcd response time means lcd can display moving images smoothly. try to get lcd with response time not higher than 25ms . The lower, the better
G> Number of colors- Look for lcd with 16.7million colors to give accurate color rendition. colors with 200k is also good but will not be displaying the real color.
Contact his guy if you need lcd
http://tipidpc.com/useritems.php?username=knytz
