US 8,942,608 B2 · Fixing unit and image forming apparatus

Abstract

The print performance of an image forming apparatus is improved by adequately estimating the behavior of a sheet receiving separation air and controlling the output of separation air. A fixing control unit 50 controls a shutter drive unit 52 defining the flow passage area on the basis of the displacement detected of the separation claw 42 to control the output of separation air. Since the sheet receiving separation air exerts a force on the separation claw 42, it is possible to estimate whether or not the behavior of the sheet is appropriate by monitoring the displacement of the separation claw 42. While different types of paper may move in different ways, the influence of separation air is dominant in the behavior of a sheet which is conveyed, and therefore the sheet can be prevented from moving in an inappropriate condition by controlling the output of separation air.

Claims12

Dependent claims

A fixing unit comprising:

a fixing unit having a pair of fixing members engaged with each other under pressure to form a fixing nip portion through which a sheet is passed to fix an image to this sheet;
an air blowing unit configured to output separation air for separating the sheet passed through said fixing nip portion from said fixing member;
an adjusting unit configured to adjust the output of said separation air;
a separation claw configured to separate the sheet passed through said fixing nip portion from said fixing member;
a detecting unit configured to detect the displacement of said separation claw;
and
a control unit configured to control the output of said separation air by controlling said adjusting unit on the basis of the displacement of said separation claw detected by said detecting unit.

4 more elements

Dependencies are inferred from the claim text.

Fixing unit and image forming apparatus

Life of this patent

Fixing unit and image forming apparatus

Life of this patent

Abstract

Claims12