Bar code scanner with laser power down feature

摘要

A proximity sensor receives light beams reflected from a goods. A proximity sensor control unit determines that the goods exists when a light quantity of the reflected light received by the proximity sensor exceeds a determination threshold value. The determination threshold value increases as elapsed time since the bar code was read last time becomes longer, and, as a result, a detection sensitivity decreases. A CPU restores a duty of irradiation of the laser beam back to 100% and resumes rotations of a motor for driving an operation optical system when the proximity sensor control unit determines that the goods exists.