Thermal fixing device that avoids overheating and image forming device having the thermal fixing device
AssigneeBrother Kogyo Kabushiki Kaisha
InventorYoshiya Tomatsu
Life of this patent
Estimating the term…
Abstract
In a thermal fixing device, a thermister, a temperature fuse and a thermostat are disposed in alignment with symmetrical positions spaced by a predetermined distance from the axial center of a heat roller, that is, a temperature distribution center of a heater. Accordingly, the temperature fuse and the thermostat can sense substantially the same temperature as that sensed by the thermister, and the temperature fuse and the thermostat function as thermal cutoff devices promptly and properly to prevent the heat roller from overheating when the heat roller is excessively heated.
Claims26
A thermal fixing device, comprising:
- a roller;
- a heater that heats the roller;
- a temperature sensor to sense a temperature of the roller;
- and
- a thermal cutoff device to interrupt power supply to the heater based on the temperature of the roller, wherein the heater has a temperature distribution that is symmetrical in an axial direction of the roller with respect to a temperature distribution center, and the temperature sensor and the thermal cutoff device are disposed facing a surface of the roller in alignment with symmetrical positions spaced by a predetermined distance, in the axial direction of the roller from the temperature distribution center.
A thermal fixing device, comprising:
- a roller;
- a heater that heats the roller;
- a temperature sensor provided proximate the roller to sense a temperature of the roller;
- and
- a thermal cutoff device provided proximate the roller to interrupt power supply to the heater, wherein the temperature sensor and the thermal cutoff device are disposed symmetrically with respect to an axial center of the roller, and are coplanar with the axial center of the roller.
A thermal fixing device, comprising:
- a roller;
- a heater that heats the roller;
- a temperature sensor provided proximate the roller to sense a temperature of the roller;
- and
- a plurality of thermal cutoff devices proximate the roller to interrupt power supply to the heater,
- wherein the plurality of thermal cutoff devices are disposed on the same circumference about an axis of the roller.
An image forming device that forms a toner image on a recording medium, comprising:
- a thermal fixing device that heats and presses the recording medium having the toner image to fix the toner image onto the recording medium, the thermal fixing device comprising:
- a roller;
- a heater that heats the roller;
- a temperature sensor provided proximate the roller to sense a temperature of the roller;
- and
- a thermal cutoff device provided proximate the roller to interrupt power supply to the heater, wherein the heater has a temperature distribution that is symmetrical in an axial direction of the roller with respect to a temperature distribution center, and the temperature sensor and the thermal cutoff device are disposed facing a surface of the roller in alignment with symmetrical positions spaced by a predetermined distance, in the axial direction of the roller from the temperature distribution center.
An image forming device that forms a toner image on a recording medium, comprising:
- a thermal fixing device that heats and presses the recording medium having the toner image to fix the toner image onto the recording medium, the thermal fixing device comprising:
- a roller;
- a heater that heats the roller;
- a temperature sensor provided proximate the roller to sense a temperature of the roller;
- and
- a thermal cutoff device provided proximate the roller to interrupt power supply to the heater, wherein the temperature sensor and the thermal cutoff device are disposed symmetrically with respect to an axial center of the roller, and are coplanar with the axial center of the roller.
An image forming device that forms a toner image on a recording medium, comprising:
- a thermal fixing device that heats and presses the recording medium having the toner image to fix the toner image onto the recording medium, the thermal fixing device comprising:
- a roller;
- a heater that heats the roller;
- a temperature sensor provided proximate the roller to sense a temperature of the roller;
- and
- a plurality of thermal cutoff devices provided proximate the roller to interrupt power supply to the heater, wherein the plurality of thermal cutoff devices are disposed on the same circumference about an axis of the roller.
A thermal fixing device, comprising:
- a roller;
- a heater that heats the roller;
- a temperature sensor provided proximate the roller to sense a temperature of the roller;
- and
- a thermal cutoff device provided proximate the roller to interrupt power supply to the heater, wherein the heater has a temperature distribution that is symmetrical in an axial direction of the roller with respect to a temperature distribution center, and at least one of the temperature sensor and the thermal cutoff device is disposed facing a surface of the roller in alignment with one of symmetrical positions spaced by a predetermined distance, in the axial direction of the roller from the temperature distribution center.
Dependencies are inferred from the claim text.