Abstract: A system for optically scanning objects, particularly bar codes over a large depth of field, uses a incandescent light source to illuminate the bar code and scans the field using a rotating polygon having mirrors with different curvature on different facets thereof which provides scanning in different focal planes in the field while temporally multiplexing these planes. The optical, electronic and mechanical components are modularly packaged on a printed circuit board adapted to be contained in a housing which may be held near and pointed at the code when it is desired to read the code.