Red, blue and green lasers respectively emit a plurality of red, blue and
green laser beams having respective output powers. The beams are
optically focused and collinearly arranged to form a composite beam which
is swept by a pair of scan mirrors in a pattern of scan lines on a
projection surface, each scan line having a number of pixels. A
controller causes selected pixels to be illuminated, and rendered
visible, by the composite beam to produce an image. A safety circuit
detects a malfunction of at least one of the lasers and the scan mirrors,
and deenergizes the at least one of the lasers and the scan mirrors upon
detection of the malfunction.