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This article from a usenet group (I'd be interested if anyone has done this on one of the more popular projectors like the Panny 100/200/300/500...)?:
>I recently purchased an H37VUA and overall I am very happy with it. I >could not have afforded any more spent on a projector setup. And for >the big screen picture I am willing to put up with the usual LCD >projector problems. It is truly awesome watching a 106" picture! > >I would like to know one thing however. Mine is projecting a definite >color uniformity problem. It is most noticable on black & white source >material.
Your LCD panel(s) are out of adjustment. Normally, the panel should be perfectly 90 degrees to the light beam. If it is slightly off at an angle, one side will be closer and the other farther away resulting in a misalignment with the other panels. Without perfect alignment of the R+G+B pixels (which would give you white), you're seeing leakage where pixels from two panels don't perfectly align. The effect will be apparent at the extreme edges of the image and less so or not at all in the center.
I opened up my Sharp H37 and aligned the panels myself...it isn't too hard, just time consuming if you're a perfectionist. There are several factors to consider:
1. That the panels are aligned properly with each other (RGB pixels overlap perfectly)
2. The panels are set at the correct distance from the lenses so that each pixel is perfectly focused and distinct.
3. All panels are aligned 90 degrees to each axis (vertical and to the lightbeam)
The fact that these three factors are so inter-related make for a trial and error process that requires some patience.
Other factors I noticed was that the alignment changes slightly (about 30% of one pixel width) as the projector warms up. Therefore, only adjust the panels after the unit has fully warmed up. Also, the alignment changes ever so slightly when the unit is placed upside down as is the case when mounting up on a shelf or ceiling. I'm not sure whether placing the unit on it's case upside down affects the optics (can anyone confirm?) I've got mine sitting upside down with blocks of hard foam along each edge of the projector so that there is no weight against the centre portion.
The basic procedure for LCD panel alignment is to block one LCD panel with a piece of opaque card while adjusting the other two panels with each other. Then repeat the process with the remaining panel. If I recall correctly, one panel is fixed whereas the other two are adjustable. The panels are fixed in place with regular Phillips screws at each corner.
LCD panel alignment DIY?
Posted - 25 May 2004 : 12:25:20
