Image forming apparatus with fixing unit having induction heating member and shielding member for controlling induction heating
US7890042B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 23, 2009 |
| Grant date | Feb 15, 2011 |
| Priority date | — |
| Expiry date | Jun 4, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G2215/2032
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An image forming apparatus includes an image forming unit and a fixing unit. The fixing unit includes a heating member; a coil arranged along an outer surface of the heating member for generating a magnetic field for induction heating the heating member; a core arranged to face the heating member with the coil located therebetween in order to form a magnetic path around the coil and made of a magnetic material; a shielding member arranged near the magnetic path generated by the coil, including a closed frame portion and made of a nonmagnetic metal; and a magnetic shielding portion for displacing the shielding member between a retracted position for permitting a magnetic flux to pass along a frame surface virtually formed inside the closed frame portion and a shielding position for shielding magnetism by the penetration of a magnetic flux inside the frame surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.