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: The present invention aims to reduce the time period of the start up operation of an image forming apparatus corresponding to an image forming apparatus operating environment. The present invention provides an image forming apparatus includes an image bearing member; a toner image forming unit for forming a toner image on the image bearing member; an image condition detection member for detecting an image condition of the image bearing member; a setting unit for setting a plurality of toner image forming conditions determined based on the output of the image condition detection member; an environment detection member for detecting an environment condition of outside air of the image forming apparatus; and a selection unit for selecting the toner image forming conditions set by the setting unit based on the output of the environment detection device from when the power is turned on to when transitioned to an image formable state.

Abstract: An image forming apparatus includes image forming means for forming an image on a recording material; a heating rotatable member for heating the heating nip on the upper in a heating nip; magnetic flux generating means for generating a magnetic flux for induction heat generation in the heating rotatable member; control means for controlling a temperature of the heating rotatable member; temperature detecting means for detecting a temperature of the heating rotatable member at a predetermined region; magnetic flux confining means for confining the magnetic flux directed toward the predetermined region of the heating rotatable member from the magnetic flux generating means in accordance with an output of the temperature detecting means; and moving means for movement the magnetic flux confining means between a magnetic-flux-confinement position and a non-magnetic-flux-confinement position, wherein when the output of the temperature detecting means indicates a temperature outside a predetermined temperature range

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: An image heating apparatus includes a coil for generating a magnetic flux by current flowing therethrough; an image heating member for heating an image on a recording material which is fed therethrough, the image heating member producing heat by eddy current generated by the magnetic flux; electric power supply control means for controlling electric power supply to the coil so as to provide the image heating member with a predetermined temperature; magnetic flux adjusting means for adjusting a magnetic flux in a direction perpendicular to a feeding direction of the recording material, the magnetic flux adjusting means having a first magnetic flux adjusting portion for reducing, by relative movement thereof relative to the coil, a magnetic flux directing toward an end of the image heating member adjacent to a sheet feedable range with respect to the direction, and a second magnetic flux adjusting portion for reducing, by relative movement thereof relative to the coil, a magnetic flux directing toward the image

Abstract: An image heating apparatus includes magnetic flux generating means for generating a magnetic flux; a heat generation member for generating heat by the magnetic flux generating means; magnetic flux adjusting means for adjusting an effective magnetic flux region toward the heat generation member with respect to a widthwise direction which is perpendicular to a feeding direction of a material to be heated, wherein the material to be heated is heated by heat generation of the heat generation member; wherein the magnetic flux adjusting means includes a magnetic flux adjusting member and moving means for moving the magnetic flux adjusting member, and wherein a temperature distribution in the heat generation member with respect to the widthwise direction is adjusted by moving the flux adjusting member to a predetermined magnetic flux adjusting position by the moving means; and discriminating means for discriminating whether the effective magnetic flux region corresponds to a size of the material to be heated or not

Abstract: An electromagnetic induction heating apparatus capable of uniformize a temperature distribution in a longitudinal direction of an induction heating member includes: an exciting coil (magnetic flux generation means); a fixation roller (induction heating member) for generating heat by electromagnetic induction heating by action of magnetic flux generated by the exciting coil the induction heating member heating a material to be heated through heat generation thereof by introducing the material to be heated into a heating portion and conveying the material to be heated in contact with the fixation roller; and magnetic flux shielding plate (magnetic flux adjusting means) for changing a distribution of a density of an effective magnetic flux which is the magnetic flux generated by the exciting coil and actable on the fixation roller, in a longitudinal direction of the heating portion perpendicular to a conveyance direction of the material to be heated.

Abstract: A heating apparatus of an electromagnetic induction type includes magnetic flux generating means for generating a magnetic flux; an induction heat generation member for electromagnetic induction heat generation by the magnetic flux at a heating portion, wherein a material to be heated is introduced to the heating portion and is fed in direct contact with the induction heat generation member or in contact to a heat transfer material for receiving heat from the induction heat generation member so that material to be heated is heated by the heat from the induction heat generation member; magnetic flux adjusting means for changing a distribution of a density of an effective magnetic flux actable on the induction heat generation member with respect to a widthwise direction perpendicular to a feeding direction of the material to be heated; wherein magnetic flux adjusting means has a plurality of steps which extend in the feeding direction and are selectable to change the distribution of the magnetic flux density in

Abstract: In a fixation apparatus using induction heating, a cooling sequence is performed, after an output of a magnetic flux generation member is terminated, to quickly effect cooling of an induction coil when needed without disposing a particular 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: A developing device has a structure in which a toner is supplied from a toner supplying container to a first toner container by a toner supplying device and also the toner is conveyed from the first toner container to a second toner container by a toner conveying member disposed so as to lie in the space between the first and second toner containers. Thus, the developing device has a reduced size and also stably supplies the toner to two developing rollers corresponding to the first and second toner containers.

Abstract: A developing device has a structure in which a toner is supplied from a toner supplying container to a first toner container by a toner supplying device and also the toner is conveyed from the first toner container to a second toner container by a toner conveying member disposed so as to lie in the space between the first and second toner containers. Thus, the developing device has a reduced size and also stably supplies the toner to two developing rollers corresponding to the first and second toner containers.

Abstract: A developing device in which, by switching the direction of rotation of a magnet roller disposed near developer receiving openings of respective first and second containers, a developer is selectively supplied to either the first container or the second container. This makes it possible to reduce the developing device and to stably supply the developer to the first and second containers.

Abstract: A high quality image forming apparatus capable of outputting a quality image at a high speed is provided, with which no unevenness is generated on an image and a fog or a change in density is less likely to occur. An exposing unit is operated by an over-filled scanner method for exposure by a rotational polygon mirror that reflects lights on a surface narrower than an incident beam width, and forms an electrostatic latent image by back area exposure for exposing a non-image part.