Optical scanner including a thermostatically controlled heater module or hermatic seal to prevent internal condensation

Disclosed is a method and apparatus for preventing condensation from forming on the internal components of an optical scanner, allowing the scanner to be moved between hot and cold environments without sacrificing scanning performance or damaging the scanner. The optical scanner can be a laser scanner or a solid state imager. One method of preventing moisture from condensing on the inside of a scanner is to control the internal temperature of the scanner. This is accomplished by installing a thermostatically controlled heater module on the inside of the scanner and warming up the scanner's internal air when the air temperature falls below a predetermined point. Another method of preventing moisture from condensing on the inside of the scanner is to hermetically seal the scanning enclosure and fill with inert gas.