Converging a rear projection LCD unit differs greatly from a standard type rear projection TV. This is because there is no magnetic deflection or sub deflection circuits in a LCD rear projector. The alignment then becomes purely mechanical since the geometry of the picture is not adjusted electrically. There are three mechanical adjustments. These adjustments align the LCDs on an angle (skew), horizontally, and vertically.
ADJUSTING METHOD
As with other rear projection systems, the green color is located in the middle. In this case the green LCD has no adjustments, therefore it is the reference color. Red and blue are to be adjusted until they converge to green. Turning three adjustment screws performs these adjustments. These screws are positioned so that when you turn each of them, a plate moves that adjust the position of the LCD. These plates are spring-loaded so that when the screws are tightened, they push the plate and when they are loosened, and the plates are pulled back. These adjustments are not as easy as they appear. They can be very tedious because it is difficult to get to some of the adjustment screws. Also, when turning the screws, the spring-loaded plates have a tendency to stick. Gently tap the assembly with the end of a screwdriver to make sure the plate has moved as much as it should.
ADJUSTING PROCEDURE
- Input a crosshatch pattern into the Video 1 input.
- Place the unit in Full Mode.
- Loosen the Locking screw for the color you want to adjust
- Perform the mechanical alignments for the misadjusted color(s) in the following order. You may have to use a solvent to loosen the lock on the screws.
- Angle (Skew)
- Horizontally
- Vertically
- Repeat above steps if necessary.
- Re-tighten the locking screws
- Put new loctite on the screws that have been moved and allow it to set before transporting.