Patent ID: 8494389
Filing Date: 2013-07-23
Classification: G03G

Abstract:
1. A fixing apparatus comprising: a first heating element; a second heating element; a first rotating member; a second rotating member configured to form a fixing nip portion together with the first rotating member, wherein a printing medium is conveyed to the fixing nip portion, and an image formed on the printing medium is fixed onto the printing medium by heat from the first and second heating elements; a first driving circuit configured to drive the first heating element; a second driving circuit configured to drive the second heating element; a control unit configured to control the first and second driving circuits; a safety element configured to shut off a power supply path for supplying an electrical power to the first and second heating elements in response with an abnormal temperature; a rotation detection circuit configured to detect a rotation state of the first and second rotating members; and a limiting circuit configured to limit a drive of the second driving circuit in accordance with an output from the rotation detection circuit, wherein the first driving circuit drives the first heating element in accordance with a control signal from the control unit, regardless of the rotation state of the first and second rotating members, and the second driving circuit drives the second heating element in accordance with a control signal from the control unit and the output from the rotation detection circuit.