Patent ID: 8903296
Filing Date: 2014-12-02
Classification: G03G

Abstract:
1. A fixing device comprising: a flexible endless fixing belt formed into a loop; a pressing rotary body pressed against an outer circumferential surface of the fixing belt to form a fixing nip therebetween through which a recording medium bearing a toner image is conveyed; a substantially tubular thermal conductor disposed opposite an inner circumferential surface of the fixing belt; and a heater disposed inside the thermal conductor to heat the fixing belt via the thermal conductor, the thermal conductor including: a center heating portion heated by the heater and disposed at a center of the thermal conductor in a longitudinal direction thereof orthogonal to a conveyance direction of the recording medium, the center heating portion having a first diameter such that an outer tubular surface of the center heating portion of the thermal conductor conducts heat from the heater to the fixing belt; and lateral end non-heating portions disposed at lateral ends of the thermal conductor in the longitudinal direction thereof, continuous with and contiguous to the center heating portion, outer tubular surfaces of the lateral end non-heating portions having a second diameter smaller than the first diameter of the center heating portion, to minimize conduction of heat from the heater to the fixing belt via the outer tubular surfaces of the lateral end non-heating portions of the thermal conductor.