Abstract: An image forming apparatus includes an image forming unit, a conveyance guide having an opening portion, a measurement unit including a light entrance portion, and a moving member including a reference portion. The measuring unit is configured to measure an image on a sheet through the opening portion in a first state where the measurement unit is positioned in a first position and the moving member is positioned in a third position. The measurement unit is configured to measure the reference portion in a second state where the measurement unit is positioned in a second position and the moving member is positioned in a fourth position.

Abstract: An Oldham coupling having play in a rotational direction and being capable of transmitting a driving force. The Oldham coupling includes a developing drive gear as a first hub, a drive coupling as a second hub, and an intermediate member that transmits a driving force between the developing drive gear and the drive coupling. The developing drive gear includes a protruded portion that is fitted to a recessed portion of the intermediate member to transmit a driving force between the developing drive gear and the intermediate member. When seen in a rotational axis direction of the Oldham coupling, the shape of a protruded portion is a substantially rhombic shape.

Abstract: An image forming apparatus is capable of suppressing deterioration in accuracy of control for switching a motor from forward to reverse rotation in a configuration in which a coupling having play in a rotation direction is interposed in a drive train between the motor and a driven member. The image forming apparatus includes a motor that rotationally drives a photosensitive drum and a developing sleeve; a coupling interposed in a drive train between the motor and the developing sleeve and/or a drive train between the motor and the photosensitive drum and having play in a rotation direction; and a CPU that controls the motor. The CPU rotates the motor forward at a speed V1 at the time of image formation, stops the motor after the end of the image formation, rotates the motor forward at a speed V2 lower than the speed V1, and then reversely rotates the motor.

Abstract: An image forming apparatus includes an image forming unit, a conveyance guide having an opening portion, a measurement unit including a light entrance portion, and a moving member including a reference portion. The measuring unit is configured to measure an image on a sheet through the opening portion in a first state where the measurement unit is positioned in a first position and the moving member is positioned in a third position. The measurement unit is configured to measure the reference portion in a second state where the measurement unit is positioned in a second position and the moving member is positioned in a fourth position.

Abstract: Provided is an Oldham coupling having a play in a rotational direction and being capable of transmitting a driving force. An Oldham coupling 1 includes a developing drive gear 99 that is a first hub, a drive coupling 89 that is a second hub, and an intermediate member 3 that transmits a driving force between the developing drive gear 99 and the drive coupling 89. The developing drive gear 99 includes a protruded portion 99a that is fitted to a recessed portion 3a of the intermediate member 3 to transmit a driving force between the developing drive gear 99 and the intermediate member 3. When seen in a rotational axis direction of the Oldham coupling 1, the shape of a protruded portion 89a is a substantially rhombic shape.

Abstract: An image forming apparatus is provided, which is capable of suppressing deterioration in the accuracy of control for switching a motor from forward rotation to reverse rotation in a configuration in which a coupling having play in a rotation direction is interposed in a drive train between the motor and a driven member. The image forming apparatus includes: one motor 92a that rotationally drives a photosensitive drum 26 and a developing sleeve 71; a coupling that is interposed in at least one of a drive train between the motor 92a and the developing sleeve 71 and a drive train between the motor 92a and the photosensitive drum 26 and has play in a rotation direction; and a CPU 53 that controls the motor 92a. The CPU 53 rotates the motor 92a forward at a speed V1 at the time of image formation, stops the motor 92a after the end of the image formation, rotates the motor 92a forward at a speed V2 lower than the speed V1, and then reversely rotates the motor 92a.

Abstract: A sensor unit includes a plurality of sensors configured to detect a toner image carried on an image bearing member, a duct including a suction portion, and a plurality of branch duct portions. The branch duct portions each includes a discharging portion having a discharge opening. At least one of the branch duct portions includes a first path for discharging air in a direction, and a second path connected with the first path at a downstream position to discharge the air in the direction. The sensor unit further includes a guide portion provided in the second path and extended crossing with an extension of one of inner walls of the first path, the guide portion being capable of branching the air in the second path toward the discharge opening.

Abstract: A sensor unit includes a plurality of sensors configured to detect a toner image carried on an image bearing member; and a duct including a suction portion; a plurality of branch duct portions. The branch duct portions each includes a discharging portion having a discharge opening. At least one of the branch duct portions includes a first path for discharging the air in a direction, and a second path connected with the first path portion at a downstream position to discharge the air in the direction. The sensor unit further includes a guide portion provided in the second path and extended crossing with an extension of one of inner walls of the first path, the guide portion being capable of branching the air in the second path toward the discharge opening.

Abstract: A cleaning device includes a cleaning member, a container, a feeding screw including a blade for feeding toner inside the container toward an outside of the container, and a loosening member, stretching along a rotation axis direction of the feeding screw, for loosening toner on a container wall surface provided around the feeding screw by being swung about a rotational axis along the rotation axis direction in a direction crossing the rotation axis direction, and the loosening member includes a contact portion for rotating the loosening member in a first direction with rotation of the feeding screw in contact with the blade when the feeding screw is in a predetermined phase range and includes an urging portion for imparting, to the loosening member, a force for rotating the loosening member in a second direction opposite to the first direction.

Abstract: First and second abutment portions are disposed in a cleaning container. The first abutment portion is arranged on the outer side relative to a first cleaning member in a width direction of a belt at a position corresponding to the first cleaning member in a circumferential direction of the belt and abuts against the outer peripheral surface of the belt. The second abutment portion is arranged on the outer side relative to a second cleaning member in the width direction at a position corresponding to the second cleaning member in the circumferential direction and abuts against the outer peripheral surface of the belt. The outer end of the first abutment portion is located on the inner side relative to the end of the first roller, and the inner end of the second abutment portion is located on the outer side relative to the end of the second roller.

Abstract: A cleaning device includes a cleaning member, a container, a feeding screw including a blade for feeding toner inside the container toward an outside of the container, and a loosening member, stretching along a rotation axis direction of the feeding screw, for loosening toner on a container wall surface provided around the feeding screw by being swung about a rotational axis along the rotation axis direction in a direction crossing the rotation axis direction, and the loosening member includes a contact portion for rotating the loosening member in a first direction with rotation of the feeding screw in contact with the blade when the feeding screw is in a predetermined phase range and includes an urging portion for imparting, to the loosening member, a force for rotating the loosening member in a second direction opposite to the first direction.

Abstract: First and second abutment portions are disposed in a cleaning container. The first abutment portion is arranged on the outer side relative to a first cleaning member in a width direction of a belt at a position corresponding to the first cleaning member in a circumferential direction of the belt and abuts against the outer peripheral surface of the belt. The second abutment portion is arranged on the outer side relative to a second cleaning member in the width direction at a position corresponding to the second cleaning member in the circumferential direction and abuts against the outer peripheral surface of the belt. The outer end of the first abutment portion is located on the inner side relative to the end of the first roller, and the inner end of the second abutment portion is located on the outer side relative to the end of the second roller.

Abstract: A belt feeding device includes a belt, a first roller, an opposing roller, a second roller, and a brush roller. (|D2s?D2m|/2)×10???(|D2s?D2m|/2)×(b/(a+b)) is satisfied, where D2m is a minimum diameter of the first roller, D2s is a maximum diameter of the first roller, ? is an entering amount of the opposing roller into the brush roller with respect to a reference line A between a portion of the first roller having the minimum diameter D2m and the second roller, a is a distance between a line passing through a rotation center of the first roller and a line passing through a rotation center of the opposing roller, and b is a distance between a line passing through a rotation center of the second roller and a line passing through the rotation center of the opposing roller.

Abstract: An image forming apparatus includes a movable member unit including a movable member, and a container connectable with the movable member unit and including a cleaning member, a sheet member and an urging member. When a friction coefficient between the sheet member and the movable member is ?1 and a friction coefficient between the sheet member and the urging member is ?2, the following relationship is satisfied: ?1>?2.

Abstract: A belt conveyance apparatus includes a plurality of support rollers, an endless belt, a regulation portion configured to regulate a shift of the endless belt in a width direction, a regulation receiving member configured to contact the regulation portion to receive a regulation force by the regulation portion, and support members disposed on an upstream side, in a conveyance direction of the endless belt, of the support rollers provided with the regulation portion to oppose each other on an inner peripheral surface side and an outer peripheral surface side of the end portion side of the endless belt in the width direction, and configured to regulate a position of the regulation receiving member when the regulation receiving member enters a contact portion with the regulation portion.

Abstract: An image forming apparatus includes a movable member unit including a movable member, and a container connectable with the movable member unit and including a cleaning member, a sheet member and an urging member. When a friction coefficient between the sheet member and the movable member is ?1 and a friction coefficient between the sheet member and the urging member is ?2, the following relationship is satisfied: ?1>?2.

Abstract: A belt feeding device includes a belt, a first roller, an opposing roller, a second roller, and a brush roller. (|D2s?D2m|/2)×10???(|D2s?D2m|/2)×(b/(a+b)) is satisfied, where D2m is a minimum diameter of the first roller, D2s is a maximum diameter of the first roller, ? is an entering amount of the opposing roller into the brush roller with respect to a reference line A between a portion of the first roller having the minimum diameter D2m and the second roller, a is a distance between a line passing through a rotation center of the first roller and a line passing through a rotation center of the opposing roller, and b is a distance between a line passing through a rotation center of the second roller and a line passing through the rotation center of the opposing roller.

Abstract: A belt conveyance apparatus includes a plurality of support rollers, an endless belt, a regulation portion configured to regulate a shift of the endless belt in a width direction, a regulation receiving member configured to contact the regulation portion to receive a regulation force by the regulation portion, and support members disposed on an upstream side, in a conveyance direction of the endless belt, of the support rollers provided with the regulation portion to oppose each other on an inner peripheral surface side and an outer peripheral surface side of the end portion side of the endless belt in the width direction, and configured to regulate a position of the regulation receiving member when the regulation receiving member enters a contact portion with the regulation portion.