Heating device, fixing device, and image forming apparatus
AssigneeRicoh Company, Ltd.
InventorHitoshi Fujiwara
Life of this patent
Estimating the term…
Abstract
A heating device includes a heater, a safety device, and a holder. The safety device has a heat-sensitive surface facing the heater. The safety device cuts off power supply to the heater in response to reaching a temperature of the heat-sensitive surface to be equal to or higher than a predetermined temperature. The holder holds the heater. The holder has a through hole that opens toward the heater and includes a step portion disposed on an inner circumferential surface of the through hole. The step portion supports an end of the heat-sensitive surface such that a central portion of the heat-sensitive surface of the safety device is not in contact with the heater.
Claims20
A heating device comprising:
- a heater;
- a safety device having a heat-sensitive surface facing the heater, the safety device configured to cut off power supply to the heater in response to a temperature of the heat-sensitive surface being equal to or higher than a predetermined temperature;
- and
- a holder configured to hold the heater, the holder forming a through hole that opens toward the heater, the holder including a step portion on an inner circumferential surface of the through hole, and the step portion configured to support an end of the heat-sensitive surface and separate a central portion of the heat-sensitive surface of the safety device from the heater, wherein
- the step portion is in contact with a region of the heat-sensitive surface, and the region is within 2 mm from an outer peripheral edge of the heat-sensitive surface toward an inner portion of the heat-sensitive surface.
A heating device comprising:
- a heater;
- a safety device having a heat-sensitive surface facing the heater, the safety device configured to cut off power supply to the heater in response to a temperature of the heat-sensitive surface being equal to or higher than a predetermined temperature;
- and
- a holder configured to hold the heater, the holder forming a through hole that opens toward the heater, the holder including a step portion on an inner circumferential surface of the through hole, and the step portion configured to support an end of the heat-sensitive surface and separate a central portion of the heat-sensitive surface of the safety device from the heater, wherein
- the holder includes three step portions, the three step portions including the step portion, and the three step portions being at three positions in a circumferential direction of the through hole.
A heating device comprising:
- a heater;
- a safety device having a heat-sensitive surface facing the heater, the safety device configured to cut off power supply to the heater in response to a temperature of the heat-sensitive surface being equal to or higher than a predetermined temperature;
- and
- a holder configured to hold the heater, the holder forming a through hole that opens toward the heater, the holder including a step portion on an inner circumferential surface of the through hole, and the step portion configured to support an end of the heat-sensitive surface and separate a central portion of the heat-sensitive surface of the safety device from the heater, wherein
- the heat-sensitive surface includes a first area not in contact with the step portion and a second area in contact with the step portion, and a ratio of the first area to the second area is 5 or more.
Dependencies are inferred from the claim text.