GB1256683A - - Google Patents

Abstract

1,256,683. Firing developed electrostatic images. ADDRESSOGRAPH MULTIGRAPH CORP. Feb. 10, 1970 [March 13, 1969], No.6436/70. Heading G2H. An apparatus for fixing developed electrostatic images comprises a chamber having a sheet guide 17 extending between an entrance 14 and exit 15, two or more infrared heaters 25 and 26, and an electric control circuit for reducing the input to the heaters after the chamber has attained a predetermined temperature and including an override system to maintain the infrared heaters operative whenever a sheet is in the chamber. In operation, a high input is supplied by control circuit, Fig. 3 (not shown) to bring the chamber to operating temperature. When the operating temperature is attained a thermostat 32, Fig. 2, opens to provide a lower input to the heaters 25, 26 which is insufficient to maintain the operating temperature. The thermostat reopens, but closes when the operating temperature is attained through the supply to the lamps 25, 26 of an intermediate input and then cycles between the lower and intermediate inputs. A switch (60), Fig.3 (not shown) actuated by a sheet passing through the guide 17 then controls the intermediate input to the lamps 25, 26. A blower, 43 blows air into a chamber 35 which circulates in the directions of the arrows.