Abstract: A developing device includes a storing portion, a stirring member, a developing roller, a shield plate, and a guide portion. The storing portion stores developer. The stirring member is rotatably provided in the storing portion and stirs the developer in the storing portion by being rotationally driven in a predetermined first rotation direction. The developing roller is rotatably provided above the stirring member, has a magnet that attracts the developer in the storing portion by a magnetic force, and is rotationally driven in a predetermined second rotation direction. The shield plate is made of a nonmagnetic material and provided at a facing position where the developing roller and the stirring member face each other. The guide portion is provided more on an upstream side in the first rotation direction than the facing position, and guides the developer from the storing portion to the developing roller side.

Abstract: A photosensitive drum is axially rotatable and has a surface on which an electrostatic latent image is formed. A developing device includes a development roller spaced from the photosensitive drum. The development roller includes a cylindrical sleeve and a coating layer, and the photosensitive drum includes a cylindrical tube and a functional layer. Each of the coating layer and functional layer is formed by dipping the sleeve or tube into a dipping bath with the sleeve or tube directed axially vertically. An axial end portion of the development roller that is lower during the dipping process is disposed opposite to an axial end portion of the photosensitive drum that is higher during the dipping process, and an axial end portion of the development roller that is higher during the dipping process is disposed opposite to an axial end portion of the photosensitive drum that is lower during the dipping process.

Abstract: A photosensitive drum is axially rotatable and has a surface on which an electrostatic latent image is formed. A developing device includes a development roller spaced from the photosensitive drum. The development roller includes a cylindrical sleeve and a coating layer, and the photosensitive drum includes a cylindrical tube and a functional layer. Each of the coating layer and functional layer is formed by dipping the sleeve or tube into a dipping bath with the sleeve or tube directed axially vertically. An axial end portion of the development roller that is lower during the dipping process is disposed opposite to an axial end portion of the photosensitive drum that is higher during the dipping process, and an axial end portion of the development roller that is higher during the dipping process is disposed opposite to an axial end portion of the photosensitive drum that is lower during the dipping process.

Abstract: A developing device includes a housing, a stirring member, a developing unit body, a driving device, a detecting device, and a control device. The housing accommodates developer supplied from a supply means and including toner and carrier. The stirring member rotates in the housing to stir the developer. The developing unit body rotates in the housing to convey the developer toward an image carrying member from the stirring member and attaches the toner to the image carrying member. The driving device rotationally drive at least one of the stirring member and the developing unit body. The detecting device detects the torque of the driving device. The control device performs a recovery process of controlling the supply means to supply at least one of the carrier and the developer to an interior of the housing when a detection result of the detecting device has a value lower than a threshold value.

Abstract: A developing device includes a storing portion, a stirring member, a developing roller, a shield plate, and a guide portion. The storing portion stores developer. The stirring member is rotatably provided in the storing portion and stirs the developer in the storing portion by being rotationally driven in a predetermined first rotation direction. The developing roller is rotatably provided above the stirring member, has a magnet that attracts the developer in the storing portion by a magnetic force, and is rotationally driven in a predetermined second rotation direction. The shield plate is made of a nonmagnetic material and provided at a facing position where the developing roller and the stirring member face each other. The guide portion is provided more on an upstream side in the first rotation direction than the facing position, and guides the developer from the storing portion to the developing roller side.

Abstract: A transfer device includes image bearing members, an intermediate transfer belt, transfer members, a transfer bias applying unit and a bias control unit. The transfer bias applying unit applies a transfer bias to the transfer. The bias control unit causes a transfer bias having a polarity opposite to that of the toner to be applied to a first transfer member during the transfer process in the first transfer nip and during an adjacent transfer process which is the non-transfer process in the first transfer nip and the transfer process in a second transfer nip adjacent to the first transfer nip. Further, the bias control unit causes a transfer bias having the same polarity as that of the toner to be applied to the first transfer member during an adjacent non-transfer process which is the non-transfer process in the first transfer nip and the non-transfer process in the second transfer nip.

Abstract: An intermediate transfer belt that temporarily holds a toner image which is formed on an image carrier and transferred to the intermediate transfer belt includes a base member, an elastic layer laminated on the base member and a surface layer covering the elastic layer. With respect to the intermediate transfer belt, a volume resistivity of the surface layer is lower than a volume resistivity of an entirety of the intermediate transfer belt.

Abstract: A transfer device includes image bearing members, an intermediate transfer belt, transfer members, a transfer bias applying unit and a bias control unit. The transfer bias applying unit applies a transfer bias to the transfer. The bias control unit causes a transfer bias having a polarity opposite to that of the toner to be applied to a first transfer member during the transfer process in the first transfer nip and during an adjacent transfer process which is the non-transfer process in the first transfer nip and the transfer process in a second transfer nip adjacent to the first transfer nip. Further, the bias control unit causes a transfer bias having the same polarity as that of the toner to be applied to the first transfer member during an adjacent non-transfer process which is the non-transfer process in the first transfer nip and the non-transfer process in the second transfer nip.

Abstract: An intermediate transfer belt that temporarily holds a toner image which is formed on an image carrier and transferred to the intermediate transfer belt includes a base member, an elastic layer laminated on the base member and a surface layer covering the elastic layer. With respect to the intermediate transfer belt, a volume resistivity of the surface layer is lower than a volume resistivity of an entirety of the intermediate transfer belt.

Abstract: An endless belt is provided with an endless belt body and a meandering prevention member in the form of a flat bar. The belt body includes a folded trace extending in the width direction thereof. The meandering prevention member is attached on one widthwise end of a circumferential surface of the belt body such that one widthwise end of the folded trace is covered thereby and the opposite longitudinal ends of the meandering prevention member abut each other in a rotating direction of the belt body. An abutting portion at the opposite ends of the meandering prevention member is arranged at a position displaced from the folded trace by a specified distance in the rotating direction of the belt body.

Abstract: An image forming apparatus includes an image bearing member with an image bearing surface adapted to move in a given direction and carry a toner image thereon. A main cleaning device is opposed to the image bearing surface and electrically removes residual toner remaining on the image bearing surface. A power supply is adapted to apply to the main cleaning device a bias having a polarity reverse to a charge polarity of the residual toner. An auxiliary cleaning device is provided near and upstream of the main cleaning device with respect to the moving direction of the image bearing surface and can be brought into contact with the image bearing surface. A support structure supports the auxiliary cleaning device and permits the auxiliary cleaning device to be moved swingingly while following a displacement of the image bearing surface during the moving.

Abstract: Disclosed is an image forming apparatus, which comprises an intermediate transfer belt (15), and a plurality of image-forming units (11) to (14) disposed along the intermediate transfer belt (15) and adapted to form toner images of different colors and sequentially transfer the toner images onto the intermediate transfer belt (15) in a superimposed manner so as to form a color toner image. The intermediate transfer belt (15) is laid across a drive roller (16), a driven roller (17) and a tension roller (18), in a tensioned condition. A rotation speed of the tension roller (18) adapted to apply a tension to the intermediate transfer belt (15) is detected to obtain a linear speed of the intermediate transfer belt (15). In a process of color-misregistration correction, a write-start timing for each toner image of the colors is adjusted based on the linear speed of the intermediate transfer belt (15).

Abstract: An image forming apparatus (10) includes image bearing members (20) having respective peripheral surfaces and arranged sequentially so that toner images of toners having different colors are formed on the peripheral surfaces, respectively, an endless belt (30) having a surface and so rotated that the toner images are sequentially transferred to the surface or a sheet (P) conveyed on the surface, transferring members (40) for transferring the toner images to the surface of the endless belt (30) or the sheet (P). The downstream-most image bearing member (20) from which the toner image is last transferred to the surface of the endless belt (30) or the sheet (P) is arranged so that a contact pressure of the downstream-most image bearing member (20) against the endless belt (30) becomes higher than contact pressures of the other image bearing members (20) against the endless belt (30).

Abstract: An image forming apparatus includes an image forming section for forming a plurality of toner images on a plurality of image bearing members respectively by an electrographic system; an endless belt to which the plurality of toner images are to be superimposedly transferred from the plurality of image bearing members, the endless belt being arranged close to the image forming section; a driving roller which the endless belt is placed on and is adapted to drive the endless belt; a driven roller which the endless belt is placed on; a detector for detecting a surface condition of the endless belt; and a controller for controlling at least one of the surface speed of the image bearing member and the moving speed of the endless belt in accordance with an output from the detector.

Abstract: An image forming apparatus (10) includes image bearing members (20) having respective peripheral surfaces and arranged sequentially so that toner images of toners having different colors are formed on the peripheral surfaces, respectively, an endless belt (30) having a surface and so rotated that the toner images are sequentially transferred to the surface or a sheet (P) conveyed on the surface, transferring members (40) for transferring the toner images to the surface of the endless belt (30) or the sheet (P). The downstream-most image bearing member (20) from which the toner image is last transferred to the surface of the endless belt (30) or the sheet (P) is arranged so that a contact pressure of the downstream-most image bearing member (20) against the endless belt (30) becomes higher than contact pressures of the other image bearing members (20) against the endless belt (30).

Abstract: An endless belt is provided with an endless belt body and a meandering prevention member in the form of a flat bar. The belt body includes a folded trace extending in the width direction thereof. The meandering prevention member is attached on one widthwise end of a circumferential surface of the belt body such that one widthwise end of the folded trace is covered thereby and the opposite longitudinal ends of the meandering prevention member abut each other in a rotating direction of the belt body. An abutting portion at the opposite ends of the meandering prevention member is arranged at a position displaced from the folded trace by a specified distance in the rotating direction of the belt body.

Abstract: An image forming apparatus includes an image bearing member with an image bearing surface adapted to move in a given direction and carry a toner image thereon. A main cleaning device is opposed to the image bearing surface and electrically removes residual toner remaining on the image bearing surface. A power supply is adapted to apply to the main cleaning device a bias having a polarity reverse to a charge polarity of the residual toner. An auxiliary cleaning device is provided near and upstream of the main cleaning device with respect to the moving direction of the image bearing surface and can be brought into contact with the image bearing surface. A support structure supports the auxiliary cleaning device and permits the auxiliary cleaning device to be moved swingingly while following a displacement of the image bearing surface during the moving.

Abstract: The difference between the light reception output signals representing the amounts of regularly and irregularly reflected light as measured, with optical detecting means that can measure the amount of regularly and irregularly reflected light simultaneously, when no toner is adhered to a transfer belt is set as a reference value, a corrected output value is calculated by correcting, based on the reference value, the difference between the light reception output signals representing the amounts of regularly and irregularly reflected light as measured when a toner image is formed, and the amount of toner adhered to the transfer belt is calculated based on the corrected output value. With transfer belts of different colors, if their surface gloss is equal to or lower than a predetermined value, the relationship between the coverage ratio and the toner adhesion amount remains approximately identical.

Abstract: Disclosed is an image forming apparatus, which comprises an intermediate transfer belt (15), and a plurality of image-forming units (11) to (14) disposed along the intermediate transfer belt (15) and adapted to form toner images of different colors and sequentially transfer the toner images onto the intermediate transfer belt (15) in a superimposed manner so as to form a color toner image. The intermediate transfer belt (15) is laid across a drive roller (16), a driven roller (17) and a tension roller (18), in a tensioned condition. A rotation speed of the tension roller (18) adapted to apply a tension to the intermediate transfer belt (15) is detected to obtain a linear speed of the intermediate transfer belt (15). In a process of color-misregistration correction, a write-start timing for each toner image of the colors is adjusted based on the linear speed of the intermediate transfer belt (15).

Abstract: Disclosed is an image forming apparatus, which comprises an intermediate transfer belt (15), and a plurality of image-forming units (11) to (14) disposed along the intermediate transfer belt (15) and adapted to form toner images of different colors and sequentially transfer the toner images onto the intermediate transfer belt (15) in a superimposed manner so as to form a color toner image. The intermediate transfer belt (15) is laid across a drive roller (16), a driven roller (17) and a tension roller (18), in a tensioned condition. A rotation speed of the tension roller (18) adapted to apply a tension to the intermediate transfer belt (15) is detected to obtain a linear speed of the intermediate transfer belt (15). In a process of color-misregistration correction, a write-start timing for each toner image of the colors is adjusted based on the linear speed of the intermediate transfer belt (15).