Abstract: An image forming apparatus includes a fixing portion, including: a heating member and a back-up member forming a nip; and an air feeding portion for feeding air to a non-sheet-passing area of at least one of the heating member and the back-up member, the air feeding portion including a fan for feeding the air, a duct, including an opening, for guiding the air fed from the fan through the opening to the non-sheet-passing area, and an adjusting member for adjusting an opening amount of the opening. The apparatus executes a first air feeding operation with a first opening amount and a first rotational frequency of the fan and a second air feeding operation with a second opening amount and a second rotational frequency, when the fixing portion fixes the images on sheets having the same widths.

Abstract: An image forming apparatus includes a fixing portion, including: a heating member and a back-up member forming a nip; and an air feeding portion for feeding air to a non-sheet-passing area of at least one of the heating member and the back-up member, the air feeding portion including a fan for feeding the air, a duct, including an opening, for guiding the air fed from the fan through the opening to the non-sheet-passing area, and an adjusting member for adjusting an opening amount of the opening. The apparatus executes a first air feeding operation with a first opening amount and a first rotational frequency of the fan and a second air feeding operation with a second opening amount and a second rotational frequency, when the fixing portion fixes the images on sheets having the same widths.

Abstract: Provided is a technology that enhances the detection precision of the residual amount of a developer. An apparatus according to the invention includes: an accommodating portion in which a developer is accommodated; a sheet-like stirring member that, by rotating, stirs the developer accommodated in the accommodating portion; a piezoelectric element that is affixed to the stirring member and that outputs voltage when being deformed; and a deflection forming portion that comes in contact with the stirring member, thereby causing the stirring member to deflect, when a free end of the rotating stirring member is outside a developer accumulation region in the accommodating portion.

Abstract: A heat fixing device includes a rotatable member for heating, a pressing roller configured to form a fixing nip portion that nips and conveys a recording material bearing a toner image, and a cooling fan configured to cool a recording material non-passing region in the rotatable member for heating in a direction orthogonal to a recording material conveying direction, wherein the pressing roller includes a rubber layer, between a cored bar and a release layer, containing a needle-shaped heat conductive filler oriented in a roller axis direction.

Abstract: A fixing apparatus includes a film, a heater that contacts the inner face of the film and is capable of changing heat distribution, and a pressure member that forms the nip portion with the heater via the film, the pressure member including a region on which a diameter is increased from a center portion toward an end portion, wherein the fixing apparatus performs heater control so that a ratio of an amount of heat generation at the end portion of the heater to an amount of heat generation at the center portion of the heater is changed based on a temperature of the end portion of the pressure member, during a period at least from when the warm-up of the fixing apparatus is started until the recording material reaches the nip portion.

Abstract: An image forming apparatus includes a fixing portion, including a heating member and a back-up member forming a nip; and an air feeding portion for feeding air to a non-sheet-passing area of at least one of the heating member and the back-up member, the air feeding portion including a fan for feeding the air, a duct, including an opening, for guiding the air fed from the fan through the opening to the non-sheet-passing area, and an adjusting member for adjusting an opening amount of the opening. The apparatus executes a first air feeding operation with a first opening amount and a first rotational frequency of the fan and a second air feeding operation with a second opening amount and a second rotational frequency, when the fixing portion fixes the images on sheets having the same widths.

Abstract: An image forming apparatus that forms a toner image on a recording medium includes an image forming unit that forms an unfixed toner image on a recording medium; a fixing unit that heats the recording medium bearing the unfixed toner image and fixes the unfixed toner image onto the recording medium at a nip portion; a heating member and a pressurizing member that touches the heating member and forms the nip portion therebetween; a first blower that blows air to a non-sheet-passing area of a small-size recording medium in the heating member; and a second blower that blows air to a non-sheet-passing area of a small-size recording medium in the pressurizing member. Upon the temperature of the non-sheet-passing area of the heating member exceeding a threshold temperature, the first blower blows without the second blower blowing, then the two blowers start blowing together.

Abstract: A developer container unit includes a container containing developer and a piezoelectric film for detecting an amount of developer in the container. A sensitivity of the piezoelectric film to a stress in a direction parallel to a film surface is greater than a sensitivity of the piezoelectric film to a stress in a direction perpendicular to the film surface, and the piezoelectric film is deformable with a movement thereof relative to the developer.

Abstract: An image forming apparatus includes an image forming device, a fixing device, a first fan configured to supply air to a first area of the fixing device, a second fan configured to supply air to a second area of the fixing device, a first temperature detector for detecting a temperature of the first area, a second temperature detector for detecting a temperature of the second area, and a control unit configured to start to operate the first fan and the second fan, wherein, when a displacement amount of a recording material with respect to a conveyance reference is a predetermined amount or larger and when the recording material is displaced toward the first area, the control unit sets a temperature for starting to drive the second fan to be lower than a temperature that is set when the positional displacement amount is less than the predetermined amount.

Abstract: A heat fixing device includes a rotatable member for heating, a pressing roller configured to form a fixing nip portion that nips and conveys a recording material bearing a toner image, and a cooling fan configured to cool a recording material non-passing region in the rotatable member for heating in a direction orthogonal to a recording material conveying direction, wherein the pressing roller includes a rubber layer, between a cored bar and a release layer, containing a needle-shaped heat conductive filler oriented in a roller axis direction.

Abstract: The image heating apparatus for heating an image formed on a recording medium has an endless belt with a base layer made of a metal material; a heater that contacts with an inner surface of the endless belt; and a backup member that forms a nip portion together with the heater through the endless belt. The image formed on the recording medium is heated while being pinched and conveyed in the nip portion. An end surface of the base layer includes a plane region and a curved surface region. When the thickness of the base layer is t, the width of the plane region in a thickness direction of the base layer is h, and the flatness ratio H of the end surface of the base layer is defined as h/t, the flatness ratio H satisfies 50%?H?90%.

Abstract: The image heating apparatus for heating an image formed on a recording medium includes an endless belt that includes a base layer made of a metal material; a heater that contacts with an inner surface of the endless belt; and a backup member that forms a nip portion together with the heater through the endless belt. The image formed on the recording medium is heated while being pinched and conveyed in the nip portion. An end surface of the base layer includes a plane region and a curved surface region. When the thickness of the base layer is t, the width of the plane region in a thickness direction of the base layer is h, and the flatness ratio H of the end surface of the base layer is defined as h/t, the flatness ratio H satisfies 50%?H?90%.

Abstract: An image heating apparatus for heating an image formed on a recording material, the apparatus including a conveying roller for conveying a recording material, the conveying roller including a metal core and an elastic layer provided outside the metal core, wherein the metal core has, in a central portion in the longitudinal direction thereof, a straight shape area having a substantially uniform diameter along the longitudinal direction and tapered shape areas, on both sides of the straight shape area, in which a diameter gradually decreases toward ends in the longitudinal direction, and wherein the elastic layer has, in a central portion in the longitudinal direction thereof, a straight shape area having a substantially uniform diameter along the longitudinal direction and inverted crown shape areas, on both sides of the straight shape area, in which a diameter gradually increases toward ends in the longitudinal direction.

Abstract: An image heating apparatus for heating an image formed on a recording material, the apparatus including a conveying roller for conveying a recording material, the conveying roller including a metal core and an elastic layer provided outside the metal core, wherein the metal core has, in a central portion in the longitudinal direction thereof, a straight shape area having a substantially uniform diameter along the longitudinal direction and tapered shape areas, on both sides of the straight shape area, in which a diameter gradually decreases toward ends in the longitudinal direction, and wherein the elastic layer has, in a central portion in the longitudinal direction thereof, a straight shape area having a substantially uniform diameter along the longitudinal direction and inverted crown shape areas, on both sides of the straight shape area, in which a diameter gradually increases toward ends in the longitudinal direction.