Dithering assemblies for barcode scanners

摘要

A compact scan module including a resonantly driven dithering assembly employing feedback and/or travel stops for scanning an illumination beam of a barcode scanner. In one construction the dithering assembly includes one or more travel stops to limit the motion of the mirror assembly with the two travel stop(s) fabricated from damped resilient material to absorb excess energy imparted on the dithering assembly. A first preferred feedback embodiment employs a Hall effect sensor wherein a feedback magnet is connected to the dithering assembly with a Hall effect sensor positioned to sense the varying magnetic field resulting from the varying position of the feedback magnet. A second feedback embodiment incorporates piezoelectric feedback wherein one or more piezoelectric strain sensors are attached to the bending member to provide the position sensing.