Apparatus for sensing different attenuation windows within an optical scanner

摘要

An apparatus for sensing different attenuation windows within an optical scanner which adjusts the power level of a laser to a maximum safe power level. The apparatus includes an attenuation sensor which senses the amount of attenuation of the laser beam by a first attenuation window, and a laser power adjuster which changes the laser power level to an optimal but safe level based upon the sensed amount of attenuation of the laser beam. The apparatus may also include a detection circuit having a threshold detection level which is capable of being adjusted based upon the laser power level.