This is an old projector which was released in May 2005. Projector image degrades over time as the lamp dims, and other internal factors affect brightness. The original rating is 1600 lumens which is not bright compared to a modern projector.
You can check to status which may give you lamp information by pressing ENTER on remote or projector and going to HELP.
You may find that replacing the lamp helps, however older lamps are expensive and could replace the whole projector with new one of higher specification, complete with 3 year warranty if you spend double as much. A new lamp will not restore a projector to its new state either. Here's a link to the lamp (for the UK), it's over £200 + VAT + delivery, and that's not even for a genuien HP lamphttp://www.every-projector-lamp.co.uk/projector-lamps.php?&brand=HEWLETT+PACKARD&model=VP6310
As I say, you can get projectors with a better spec for as little as £372 + vat + delivery. This one is similar to yours, in that it is a 4x3 business projector. It has an XGA resolution. (Yours is VGA). It is 2000 lumen brightness and it has a 3 year warranty. http://www.ivojo.co.uk/projector-spec.php?pid=Samsung_SP-L201
Hope this helps...