Abstract: An image heating apparatus includes a hollow image heating roller having a through hole at one axial end portion side thereof; a bearing fitted around the roller; a heat insulating bush fitted around the roller between the roller and the bearing; a retaining ring for preventing the heat insulating bush from moving relative to the roller; an annular spacer provided between the heat insulating bush and the retaining ring, the annular spacer being provided with an inwardly protruded key portion engageable with the through hole.

Abstract: An image heating apparatus includes a roller, a heating portion disposed within the roller, a bearing portion fitted around an end portion of the roller to rotably support the roller, and a retaining ring attached at an axially predetermined position of the roller to restrict the roller from moving in a axial direction of the roller with respect to the bearing portion. The retaining ring includes first and second projections fitted into a hole portion of the roller. Profiles of side surfaces of these first and second projections abutting edges of the hole portion in a circumferential direction are recessed in the circumferential direction.

Abstract: An image heater a hollow heating roller having a hole at an axial end portion thereof; a bearing supporting the heating roller; a heat insulating bush fitted between an outer surface of the heating roller and the bearing; a retaining ring for retaining the heat insulating bush in an axial direction of the heating roller, the retaining ring including a projection engaging with the hole; an annular spacer provided between the retaining ring and the heat insulating bush, wherein the spacer includes a connecting portion having a connecting hole, the retaining ring includes a hooking portion engaging with the connecting hole.

Abstract: An image heating apparatus includes a coil for generating a magnetic flux by a current flowing therethrough; an image heating member having an electroconductive layer in which an eddy current is produced by the magnetic flux by which heat is generated, the image heating member being effective to heat an image on a recording material; an electroconductive magnetic flux adjusting member movable from a first position and a second position to decrease the eddy current produced in the image heating member by the magnetic flux; a temperature sensor for sensing a temperature of image heating member; electric power control means for control electric power supplied to the coil on the basis of an output of the temperature sensor, wherein the electric power control means changes an electric power condition to be supplied to the coil before start of the movement from the first position to the second position of magnetic flux adjusting member.

Abstract: An image heating apparatus includes a coil for generating a magnetic flux by a current flowing therethrough; an image heating member having an electroconductive layer in which an eddy current is produced by the magnetic flux by which heat is generated, to heat an image on a recording material; an electroconductive magnetic flux adjusting member movable from a first position and a second position to decrease the eddy current produced in the image heating member by the magnetic flux; a sensor for sensing the temperature of the image heating member; and a controller for controlling electric power supplied to the coil on the basis of an output of the sensor. The controller changes an electric power condition to be supplied to the coil before start of the movement from the first position to the second position of magnetic flux adjusting member.

Abstract: An image heating apparatus includes a hollow image heating roller having a through hole at one axial end portion side thereof; a bearing fitted around the roller; a heat insulating bush fitted around the roller between the roller and the bearing; a retaining ring for preventing the heat insulating bush from moving relative to the roller; an annular spacer provided between the heat insulating bush and the retaining ring, the annular spacer being provided with an inwardly protruded key portion engageable with the through hole.

Abstract: An image heating apparatus includes a roller, a heating portion disposed within the roller, a bearing portion fitted around an end portion of the roller to rotably support the roller, and a retaining ring attached at an axially predetermined position of the roller to restrict the roller from moving in a axial direction of the roller with respect to the bearing portion. The retaining ring includes first and second projections fitted into a hole portion of the roller. Profiles of side surfaces of these first and second projections abutting edges of the hole portion in a circumferential direction are recessed in the circumferential direction.

Abstract: An image heating apparatus includes a coil for generating a magnetic flux by a current flowing therethrough; an image heating member having an electroconductive layer in which an eddy current is produced by the magnetic flux by which heat is generated, to heat an image on a recording material; an electroconductive magnetic flux adjusting member movable from a first position and a second position to decrease the eddy current produced in the image heating member by the magnetic flux; a sensor for sensing the temperature of the image heating member; and a controller for controlling electric power supplied to the coil on the basis of an output of the sensor. The controller changes an electric power condition to be supplied to the coil before start of the movement from the first position to the second position of magnetic flux adjusting member.

Abstract: An image heating apparatus includes a coil for generating a magnetic flux by a current flowing therethrough; an image heating member having an electroconductive layer in which an eddy current is produced by the magnetic flux by which heat is generated, the image heating member being effective to heat an image on a recording material; an electroconductive magnetic flux adjusting member movable from a first position and a second position to decrease the eddy current produced in the image heating member by the magnetic flux; a temperature sensor for sensing a temperature of image heating member; electric power control means for control electric power supplied to the coil on the basis of an output of the temperature sensor, wherein the electric power control means changes an electric power condition to be supplied to the coil before start of the movement from the first position to the second position of magnetic flux adjusting member.

Abstract: An image heating apparatus includes a heating rotatable member for heating an image on a recording material in a heating nip; a magnetic flux generator for generating a magnetic flux for induction heat generation in the heating rotatable member; a magnetic flux confining device for confining the magnetic flux directed toward a predetermined region of the heating rotatable member from the magnetic flux generator; and a moving device for repeatedly moving the magnetic flux confining device during a heating operation between the operating position and a retracted position retracted from the operation position, when the recording material which has a predetermined width overlapping with a part of the predetermined region is continuously heated by the apparatus.

Abstract: A heating apparatus of an electromagnetic induction heating type includes a coil and a roller which generates heat by the action of magnetic flux generated from the coil. A recording material is heated by the roller. The heating apparatus further includes a movable magnetic flux decreasing member for decreasing magnetic flux, generated from the coil, acting on the roller. In the heating apparatus, a shutter is moved toward an effective position at which a temperature in a non-conveyance area is lowered when a recording material having a size lower than a maximum conveyable size is conveyed, and is moved away from the effective position depending on the temperature in the non-conveyance area, irrespective of the size of the recording material to be conveyed.

Abstract: In an electromagnetic induction heating-type heating apparatus for moving a temperature decreasing member toward or apart from an effective position where a temperature in a predetermined area is decreased in order to take countermeasure against temperature rise at a non-sheet passing portion of a heating roller, a Curie temperature of the heating roller is not less than a predetermined image heating temperature and is less than a heat-resistant temperature of the heating apparatus.

Abstract: Information on a temperature of a heat generation member at a position which is in the neighborhood of an end portion of a conveyance area of a material, to be heated, having a maximum size and in the neighborhood of a non-conveyance area of a material, to be heated, having a size smaller than the maximum size is detected by temperature information detector, and a changer lowers a target temperature of the heat generation member depending on a detection result of the temperature information detector. Thereafter, when the detection result of the temperature information detector reaches a predetermined temperature, a magnetic flux adjusting member is started to be moved by a moving device.

Abstract: An image heating apparatus includes a heating rotatable member for heating an image on a recording material in a heating nip; magnetic flux generating means for generating a magnetic flux for induction heat generation in the heating rotatable member; magnetic flux confining means for confining the magnetic flux directed toward a predetermined region of the heating rotatable member from the magnetic flux generating means; and moving means for repeatedly moving the magnetic flux confining means during a heating operation between the operating position and a retracted position retracted from the operation position, when the recording material which has a predetermined width overlapping with a part of the predetermined region is continuously heated by the apparatus.

Abstract: An image heating apparatus includes a coil for generating a magnetic flux by a current flowing therethrough; an image heating member having an electroconductive layer in which an eddy current is produced by the magnetic flux by which heat is generated, the image heating member being effective to heat an image on a recording material; an electroconductive magnetic flux adjusting member movable from a first position and a second position to decrease the eddy current produced in the image heating member by the magnetic flux; a temperature sensor for sensing a temperature of image heating member; electric power control means for control electric power supplied to the coil on the basis of an output of the temperature sensor, wherein the electric power control means changes an electric power condition to be supplied to the coil before start of the movement from the first position to the second position of magnetic flux adjusting member.

Abstract: In an electromagnetic induction heating-type heating apparatus for moving a temperature decreasing member toward or apart from an effective position where a temperature in a predetermined area is decreased in order to take countermeasure against temperature rise at a non-sheet passing portion of a heating roller, a Curie temperature of the heating roller is not less than a predetermined image heating temperature and is less than a heat-resistant temperature of the heating apparatus.

Abstract: Information on a temperature of a heat generation member 7 at a position which is in the neighborhood of an end portion of a conveyance area of a material S, to be heated, having a maximum size and in the neighborhood of a non-conveyance area of a material, to be heated, having a size smaller than the maximum size is detected by temperature information detection means 22 and 23, and a change means 171 lowers a target temperature of the heat generation member 7 depending on a detection result of the temperature information detection means. Thereafter, when the detection result of the temperature information detection means reaches a predetermined temperature, a magnetic flux adjusting member 18 is started to be moved by a moving means 21.

Abstract: A heating apparatus of an electromagnetic induction heating type includes a coil and a roller which generates heat by the action of magnetic flux generated from the coil. A recording material is heated by the roller. The heating apparatus further includes a movable magnetic flux decreasing member for decreasing magnetic flux, generated from the coil, acting on the roller. In the heating apparatus, a shutter is moved toward an effective position at which a temperature in a non-conveyance area is lowered when a recording material having a size lower than a maximum conveyable size is conveyed, and is moved away from the effective position depending on the temperature in the non-conveyance area, irrespective of the size of the recording material to be conveyed.

Abstract: In a widthwise direction of a heating roller perpendicular to a sheet conveyance direction, an amount of magnetic flux acting on the heating roller in the neighborhood of an end portion of the heating roller is larger than that at a center portion of the eating roller, so that it is possible to prevent a lowering in temperature at the heating roller end portion. Further, in a temperature range in which a temperature of the heating roller is higher than a fixation temperature and is lower than a heat-resistant temperature of a heating apparatus, the heating roller has a temperature area in which a resistance thereof is lowered, so that it is possible to reduce temperature rise in a differential area between a large-sized sheet passing area and a small-sized sheet passing area when a sheet having a size smaller than a maximum size (non-sheet passing portion temperature rise).

Abstract: An image heating apparatus is provided, which includes: a heating member for heating an image on a recording material; a temperature control unit for controlling a temperature of the heating member to a predetermined set temperature; a waiting state setting unit for setting a waiting state in which the temperature of the heating member is controlled to a first set temperature; and a waiting state releasing unit for releasing the waiting state in a shorter time between a set time from start of a waiting state releasing operation and a time needed to reach a second set temperature at which the waiting state is released. An image formable state can be recovered from a low power mode in a short time.