Patent ID: 6505016
Filing Date: 2003-01-07
Classification: G03G

Abstract:
An image forming apparatus comprising:a fixing unit configured to fix a toner image having at least one color toner and a black toner on a support upon application of heat and pressure thereto, said fixing unit comprising: a fixer configured to heat the toner image on the support to a first temperature not lower than a temperature at which the at least one color toner and the black toner at least soften and configured to cool the toner image to a second temperature lower than a temperature at which the at least one color toner and the black toner solidify while a surface of the fixer is in contact with the toner image; and a pressure applicator configured to press the toner image toward the fixer upon application of pressure P at least when the toner image is heated at the first temperature, wherein the surface of the fixer has a ten-point mean roughness Rz not greater than 20 &mgr;m, and wherein the pressure P satisfies the following relationships: ((1/100)Ã—log &eegr;c)/15&lE;P&lE;((9/5)Ã—log &eegr;câˆ’4/5)/15, and ((1/100)Ã—log &eegr;b)/15&lE;P&lE;((9/5)Ã—log &eegr;bâˆ’4/5)/15, wherein P represents the pressure in units of 9.8Ã—100 N/m, and &eegr;c and &eegr;b represent viscosities of the at least one color toner and the black toner at the first temperature in units of centi-poise, respectively.