摘要:
A heating device utilizing electromagnetic induction is provided with an induction heating unit that is opposed to a heating member and causes the heating member to heat through electromagnetic induction. The induction heating unit has an exciting coil for generating a magnetic field and a coil guide member on which the exciting coil is wound. The exciting coil is formed in at least two layers in such a manner that a first layer is formed on a circumferential surface of the coil guide member by winding a plurality of turns and a second layer is formed around and outside the first layer on the side opposite to the coil guide member, and winding of each of the second layer and following layers is started from a position close to a winding start position of the first layer.
摘要:
A short ring is provided outside a support frame. In the short ring, eddy current is generated in such a direction as to cancel apart of a magnetic flux developed from the exciting coil when it is fed with current, which the part of the magnetic flux leaks to outside. When the eddy current is generated, a magnetic field is developed in such a direction as to cancel the magnetic field by the leaking flux, as taught by Fleming's law. The result is that unnecessary radiation by the leaking flux is prevented, and hence noise generation in other members or devices is suppressed.
摘要:
In a fixing unit 230, a medium introducing port 250 is provided near a gripping part 230a of a housing 230, and a sheet material 90 to be subjected to a fixing process is guided to the medium introducing port. A shutter 260 is provided slanted at a given angle with respect to a gripping surface 240 of the gripping part 230a of the fixing unit 230 such that the shutter has a fulcrum at a part thereof, which is closer to the gripping part 230a of the fixing unit 230, at the medium introducing port 250, and the shutter 260 is turnable to a position to close the medium introducing port 250 while resisting the urging forces of the twisted springs 270.
摘要:
A fixing device is formed by using a heat generating roller having magnetism and electric conductive characteristics and a magnetizing coil opposed to the outer peripheral of the heat generating roller and generating heat on the heat generating roller by an electromagnetic induction. The magnetizing coil is formed in such a manner that 60 copper wires whose surfaces are insulated and have the outside diameter of 0.2 mm are bundled to form a bundle of wires and the bundle of wires is drawn in the direction of rotation axis of the heat generating roller and wound in the direction of a circumference of the heat generating roller. Further, the magnetizing coil is disposed so that the bundles of wires mutually come into close contact along the circumference of the heat generating roller to cover the upper half of the heat generating roller.
摘要:
An image heating apparatus and heat generating rotary member for use in the image heating apparatus has a fixing roller including a magnetic metal layer and a non-magnetic metal layer, and the non-magnetic metal layer is provided on the outer side of the magnetic metal layer and is thinner than the magnetic metal layer.
摘要:
A fixing device as an image heating device is provided, by which a difference in glossiness is not caused in a recording medium in the axial direction of a pressure roller. When a print request is issued during the end-processing sequence, an electric power applied to a magnetization coil via an exciting circuit is dropped to 0 by controlling means during the start-processing sequence, and after an appropriate interval, the heating with full power is restarted by the controlling means. By so doing, the decrease in temperature at both ends of a fixing belt and a heat-generating roller in the axial direction can be compensated.
摘要:
The present invention relates to an image forming apparatus that enables the occurrence of print defects due to a first print start time delay to be eliminated without using a temperature sensor that has a small thermal time constant. When the temperature of a fixing belt serving as an image heating body is greater than or equal to a predetermined temperature following the elapse of a fixed time after an image forming operation is started, recording paper is transported to a nip area (fixing area) of a fixing apparatus before the temperature detected by a temperature sensor reaches a predetermined image fixing temperature, and an image forming operation is started immediately.
摘要:
An image heating device is operational to estimate a temperature of a pressure roller so as to determine a set temperature for a roller belt in a subsequent image heating period.
摘要:
The present invention relates to an image forming apparatus that enables the occurrence of print defects due to a first print start time delay to be eliminated without using a temperature sensor that has a small thermal time constant. When the temperature of a fixing belt serving as an image heating body is greater than or equal to a predetermined temperature following the elapse of a fixed time after an image forming operation is started, recording paper is transported to a nip area (fixing area) of a fixing apparatus before the temperature detected by a temperature sensor reaches a predetermined image fixing temperature, and an image forming operation is started immediately.
摘要:
An image heating device is provided with reduced cost, by which a difference in glossiness among printed images on recording media is eliminated, and the wrapping of a belt and the like at a high temperature is prevented. In the image heating device, controlling means estimates a temperature of a pressure roller according to at least one of a temperature of a belt detected by a temperature sensor and a variation with time in the detected temperature from completion of the heating after application of an electric power to the magnetization coil by an exciting circuit is stopped and the heating of the belt by the heating roller is stopped, so as to determine a set temperature for the belt in a subsequent image heating period.