Abstract: A thermal fixing device includes a fixing member, a flexible endless belt, a flexible endless belt, a rotary pressure member, a heating unit, and a rotation detector. The flexible endless belt is disposed on an outer circumferential surface of the fixing member. The rotary pressure member is disposed parallel to and pressing against the fixing member via the endless belt. The heating unit heats the endless belt. The rotation detector detects a rotation speed of the endless belt. The heating unit is powered off when the rotation speed of the endless belt detected by the rotation detector is at or below a predetermined threshold value.

Abstract: An image forming apparatus for forming an image on each of recording media includes an optical sensor to irradiate each of the recording media with light to detect smoothness of each of the recording media according to a strength of specularly reflected light of the light with which each of the recording media is irradiated, and a processor to compare the smoothness of the recording media to determine whether a normal image can be formed on one of the recording media having a smoothness detected last.

Abstract: An image forming apparatus includes a conveyance passage unit, a fixing device, an optical sensor, a fixing condition adjuster, and a regulator. A recording medium passes through the conveyance passage unit. The fixing device fixes a toner image onto the recording medium. The optical sensor includes a light-emitting device and a light-receiving device to detect smoothness of the recording medium according to strength of light received. The fixing condition adjuster adjusts fixing conditions according to the smoothness detected. The regulator is disposed in the conveyance passage unit to regulate conveyance of the recording medium, such that at least a part of the recording medium passes through an irradiated area including an intersection that is determined by an emission angle of a first optical axis of light emitted by the light-emitting device and a reflection angle of a second optical axis of light received by the light-receiving device.

Abstract: A fixing device includes a rotatable, endless fixing belt; a rotatable contact member configured to contact a circumferential surface of the fixing belt to form a nip in association with the fixing belt; and a heating member disposed at an interior surface of the fixing belt, configured to heat the fixing belt. The heating member includes a multiple heat sources arranged along the width of a sheet of recording media in a direction perpendicular to a sheet conveyance direction. A controller changes an area to be heated by each heat source based on image data and corresponding to an unfixed image on the sheet. The fixing belt is heated by the heating member so that the unfixed image on the sheet that has been conveyed to the nip is fixed onto the sheet at least with heat. The heating member is disposed at a portion other than the fixing nip.

Abstract: A fixing device includes a rotatable fuser member, a rotatable pressure member, a heater, and a controller. The rotatable fuser member is subjected to heating. The rotatable pressure member is disposed opposite the fuser member. The pressure member presses against the fuser member to form a fixing nip therebetween, through which multiple recording media, each spaced apart from each other by an interval distance in a conveyance direction, are sequentially conveyed at a conveyance speed. The heater is disposed adjacent to the fuser member to heat the fuser member. The controller is operatively connected to the heater to control power supply to the heater through a series of on-off switching control cycles, each including an on-time during which the heater power supply is on, and an off-time during which the heater power supply is off, in synchronization with conveyance of the recording medium.

Abstract: A fixing device includes a rotatable fuser member, a rotatable pressure member, a heater, a temperature detector, and a controller. The rotatable fuser member is subjected to heating. The rotatable pressure member is disposed opposite the fuser member. The pressure member presses against the fuser member to form a fixing nip therebetween. The heater is disposed adjacent to the fuser member to heat the fuser member. The temperature detector is directed to at least one of the fuser member, the pressure member, and the heater to detect an operational temperature of the fixing device. The controller is operatively connected to the temperature detector and the heater to control power supply to the heater according to readings of the temperature detector, so as to regulate the detected operational temperature at a setpoint temperature that is variable depending on a print page printed on the recording medium.

Abstract: An image forming apparatus includes an image forming device to form a toner image on a recording medium under a prescribed image forming condition, a fixing device to fix the toner image borne on the recording medium thereonto by heating the recording medium based on target fixing temperature, and a detector to detect a type of recording medium. The type is used in setting at least one of the image forming condition and the target fixing temperature. The inequality Tb>Ta is established when Ta represents a time period needed to reach a setting of fixing temperature allocated to the recording medium with its tip detected by the detector after detection of the tip and Tb represents a time period needed for the recording medium with its tip detected by the detector to reach the fixing device after detection of the tip.

Abstract: The fixing device using an electromagnetic induction heating (IH) method includes a fixing sleeve having a heating layer, a pressure roller to form a nip while contacting the fixing roller and rotate to drive the fixing sleeve, a temperature detector to detect a temperature on a circumference of the fixing sleeve, and an excitation coil provided near the fixing sleeve and configured to perform induction heating of the heating layer of the fixing sleeve based on the detection result from the temperature detector. The fixing device is configured to change a rotation speed of the fixing sleeve in a standby time during which the fixing sleeve, while rotating, is controlled to be heated so as to maintain a target temperature when a periodic temperature difference occurs on a circumference of the fixing rotary member and having a fluctuation amplitude larger than a predetermined value compared to the target temperature.

Abstract: A fixing device includes a rotatable fixing member to rotate while contacting an unfixed image; a pressure member to form a fixing nip with the fixing member; a heating member having a plurality of heating elements divided in a direction perpendicular to a conveyance direction of a sheet; a heat performance sensor to detect heating performance of each heating element of the heating member, and an controller to control the heating member. The controller controls each heating element independently such that a temperature of a portion of the fixing member corresponding to a blank area becomes lower than the temperature of a portion of the fixing member corresponding to an image area; and controls the temperature to be maintained at each heating element based on the detection result of the heating performance of each heating element detected by the heat performance sensor.

Abstract: A fixing device includes a fixing rotary body, an opposed member, a heater, and a heating controller. The opposed member opposes the fixing rotary body to form a nipping portion therebetween. The heater includes heat generators arranged in a width direction of a recording medium. When the recording medium fed to the nipping portion has an image area and a non-image area, the heating controller controls the outputs of the heat generators based on image information so that a first heat generator of the heat generators corresponding to the image area is higher in temperature and a second heat generator of the heat generators corresponding to the non-image area is lower in temperature. Based on information other than the image information, the heating controller temporarily shifts an area of the fixing rotary body corresponding to the non-image area to a temperature differing from a normal temperature.

Abstract: A fixing device includes a rotatable, endless fixing belt; a rotatable contact member configured to contact a circumferential surface of the fixing belt to form a nip in association with the fixing belt; and a heating member disposed at an interior surface of the fixing belt, configured to heat the fixing belt. The heating member includes a multiple heat sources arranged along the width of a sheet of recording media in a direction perpendicular to a sheet conveyance direction. A controller changes an area to be heated by each heat source based on image data and corresponding to an unfixed image on the sheet. The fixing belt is heated by the heating member so that the unfixed image on the sheet that has been conveyed to the nip is fixed onto the sheet at least with heat. The heating member is disposed at a portion other than the fixing nip.

Abstract: A fixing device includes a fixing rotary body, an opposed member opposing the fixing rotary body to form a nipping portion, and a heater to heat the fixing rotary body. The heater includes heat generators arranged in a width direction of a recording medium and separately supplied with power. When an unfixed image on the medium has an image area and a non-image area, power supplied to each of the heat generators is controlled so that, of the heat generators, a first heat generator corresponding to the image area becomes a higher temperature and second heat generators corresponding to the non-image area becomes a lower temperature. When the second heat generators are adjacent to each other, power supplied to one of the second heat generators closer to the image area is set to be greater than power supplied to another of the second heat generators farther from the image area.

Abstract: A fixing device includes a heating device to heat an endless rotary body with radiant heat, a power source to supply power to the heating device, a first heat source to heat a region on the endless rotary body corresponding to a width of the small size sheet, and a second heat source to heat regions on the endless rotary body corresponding to both widthwise ends of the large size sheet outside the width of the small size sheet. The power source supplies power only to the first heat source when the small size sheet is printed and to both the first and second heat sources when the large size sheet is printed. The power source supplies more power to the first heat source when the small size sheet is printed than when the large size sheet is printed within a maximum power available to the fixing device.

Abstract: A disclosed fixing apparatus includes a heat generating layer; an exciting coil; a magnetic shunt layer; a degaussing member; and a magnetic flux adjusting unit. A heat generating rotor is configured with at least the heat generating layer, the exciting coil is arranged outside the heat generating rotor and the degaussing member is arranged inside the heat generating rotor. The fixing apparatus is configured to control a temperature of the heat generating layer with a self temperature control function using a Curie temperature of the magnetic shunt layer which is disposed in an opposing location of the exciting coil. A magnetic path forming member which forms a magnetic path of the exciting coil is arranged on the back face side of the degaussing member that is the reverse side of the magnetic shunt layer with the degaussing member inbetween.

Abstract: A fixing device in an image forming apparatus includes a conveyance member to convey a recording medium at a fixing nip where an image carried on the recording medium is fixed onto it; a plurality of temperature detectors to detect temperature of the conveyance member, the detectors being disposed at both end portions of the conveyance member outside an area where a maximum-sided recording medium passes through; a guide member to guide the recording medium toward the fixing nip; and a guide plate displacing unit to displace a part of the guide member in a direction orthogonal to a conveyed surface of the recording medium to be conveyed at the fixing nip, based on temperature difference detected by the plurality of temperature detectors.

Abstract: A fixing device includes a fixing rotary body rotatable in a predetermined direction of rotation to radiate infrared rays; a pressing rotary body, rotatable in a direction counter to the direction of rotation of the fixing rotary body, pressed against the fixing rotary body to form a fixing nip therebetween through which a recording medium bearing a toner image is conveyed; a heater disposed opposite the fixing rotary body to heat the fixing rotary body; a temperature detector spaced apart from the fixing rotary body to detect a temperature of the fixing rotary body based on the infrared rays from the fixing rotary body and disposed below the fixing nip in a vertical direction; and a tube disposed between the fixing rotary body and the temperature detector, the tube through which the infrared rays from the fixing rotary body enter the temperature detector.

Abstract: An elastic layer is provided on a surface of one of a metal core and a substrate. A fixing member and a pressure member press into each other and collectively create a nip therebetween. A toner image is conveyed and fixed when passing through the nip. A thickness of the elastic layer is different in at least two widthwise regions by the same amount from the other region. A pair of edges of a prescribed size of the transfer sheet pass through these two widthwise regions, respectively.

Abstract: A fixing unit includes a fixing member to fuse a toner image on a recording medium on the recording medium; a pressure member to press against the fixing member to define a first nip between the fixing member and the pressure member through which the recording medium is transported; a shifting unit to move the pressure member relative to the fixing member to increase or decrease a pressure of the first nip; a curling correction unit disposed downstream from the first nip in a transport direction of the recording medium that imparts a second curling direction to the recording medium; and a variable setting unit operatively connected to the curling correction unit to variably set an amount of the second curling direction to the recording medium by the curling correction unit depending on the first nip pressure increased or decreased by the shifting unit.

Abstract: A fixing device includes an endless belt formed into a loop and rotatable in a given direction of rotation. An opposed rotary body contacts the endless belt to form a fixing nip therebetween through which a recording medium bearing a toner image is conveyed. A heater is disposed in proximity to an irradiation span spanning on an inner circumferential surface of the endless belt in a circumferential direction thereof to emit light that irradiates and heats the irradiation span of the endless belt. A shield is interposed between the heater and the irradiation span of the endless belt in a diametrical direction thereof to shield the irradiation span of the endless belt from heated air surrounding the heater.

Abstract: A fixing device includes a fixing member, an induction heating unit, a pressing member, and a damage detection unit. The fixing member heats a toner image on a recording medium to fix the toner image onto the recording medium. The induction heating unit heats the fixing member by electromagnetic induction. The pressing member presses the fixing member to form a fixing nip portion. The fixing member includes a heat insulating elastic layer and a sleeve layer. The sleeve layer is located outside the heat insulating elastic layer and is provided with an outer conductive layer that generates heat from a magnetic flux generated by the induction heating unit. The damage detection unit is connected to the outer, conductive layer.