Reflectivity of the polygon mirror is measured at 30ß of fixed incident angle. In actual applications, however, incident angle will vary in accordance with rotation of the mirror since incident angle of laser beam to the scanner is fixed. As a result, traveling distance of the laser beam through the overcoat will vary which will cause variation in the reflectivity. Typically, when incident angle changes from 10ß degrees to 60ß there will be approximately 6ß/. variation (increase) in the reflectivity.

There are three basic coating for polygon mirror. They are SiO2 single coat, multi coat and Au coat. We offer these coating depending on customer needs.