IMAGE FORMING APPARATUS AND IMAGE FORMING METHOD

摘要

An image forming apparatus includes a first heater disposed opposite and heating at least a center of a fixing belt in an axial direction thereof and a second heater disposed opposite and heating at least a lateral end of the fixing belt in the axial direction thereof. A power supply supplies power to the first heater and the second heater. A controller that controls the power supply includes a calculator to calculate an elapsed time elapsed after at least one of the first heater and the second heater starts heating the fixing belt. The controller controls the power supply to supply power to the first heater and the second heater such that a power density of the second heater is greater than a power density of the first heater when the elapsed time calculated by the calculator is smaller than a predetermined time.

主权项

1. An image forming apparatus comprising:
an endless fixing belt rotatable in a predetermined direction of rotation; an opposed member contacting 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; an abutment to contact the fixing belt in an absorption span of the fixing belt in an axial direction thereof where the abutment absorbs heat from the fixing belt; a first heater disposed opposite and heating at least an inboard span of the fixing belt inboard from the absorption span in the axial direction thereof; a second heater disposed opposite and heating at least the absorption span of the fixing belt; a first temperature detector disposed opposite the opposed member to detect a temperature of the opposed member; a power supply connected to the first heater and the second heater to supply power to the first heater and the second heater; and a controller operatively connected to the first temperature detector and the power supply to control the power supply, the controller to control the power supply to supply power to the first heater and the second heater such that a power density of the second heater is greater than a power density of the first heater when the temperature of the opposed member detected by the first temperature detector is smaller than a preset first temperature.