Heat sensor arrangement for contactless monitoring of fixer roller surface temp. in electrophotographic printer or copier

摘要

The heat sensor arrangement has a temp. sensor at a distance from the outer surface of a fixing roller. The temp. sensor is an infrared sensor (3a,b) to detect the infrared radiation emanating from the surface of the fixing roller. A collecting lens (6) between the surface of the fixing roller and the temp. sensor focusses the infrared radiation from the roller surface into the sensor (9).