Video Projectors

The simplest version of the color wheel used in a one-chip DLP projector has four segments: three for the primary colors (red, green, blue) and one clear. The clear segment increases brightness. For home-theater use, improved performance, including better blacks, can be obtained by omitting this white segment, though at some sacrifice in peak light output.

Some manufacturers have recently begun using a six-segment color wheel, with two bands of each primary color. This arrangement appears to reduce the visibility of the rainbow effect. But a six-segment wheel operates at a higher speed, which demands that the mirrors switch faster. Not all DMDs can operate at this higher speed. (One that can is used in the Sèleco DLP projector reviewed elsewhere in this issue, but its resolution is limited to 848x600, or 848x480 in widescreen operation.) A six-segment wheel also decreases maximum brightness.—TJN