Optical scanning system minimizing average laser power and improving aiming

摘要

According to a first aspect of the present invention there is provided an optical system for and a method of reading bar code symbols on a target by moving a laser beam directed toward the target in a scan across the symbol during a scan period that commences and ends at opposite scan end-limiting positions, respectively, of the scan. Power usage of the system is minimized by intermittently operating and energizing a light source during the scan period over a duty cycle prior to reading the symbol, to emit the laser beam for a working time period which is less than, and a fraction of, the scan period. The intermittent and cyclical nature of energizing the light source produces multiple images of the light beam on the symbol to visually enhance the aiming of a hand-held scanner at the symbol.