Abstract: A powder container is for use with an image forming apparatus, and the image forming apparatus includes a driving protrusion that is rotatable and that protrudes toward an upstream side in an insertion direction in which the powder container is inserted. The powder container includes a container body to store powder, a cap attached to the container body, and a transmitted structure provided on the cap to contact the driving protrusion. The transmitted structure extends outward from an outer circumference of the powder container. The cap is rotatable relative to the container body in a predetermined angular range. The rotation of the cap relative to the container body is restricted so that the container body rotates along with the rotation of the cap when the rotation of the cap exceeds the predetermined angular range.

Abstract: A powder container is for use with an image forming apparatus, and the image forming apparatus includes a driving protrusion that is rotatable and that protrudes toward an upstream side in an insertion direction in which the powder container is inserted. The powder container includes a container body to store powder, a cap attached to the container body, and a transmitted structure provided on the cap to contact the driving protrusion. The transmitted structure extends outward from an outer circumference of the powder container. The cap is rotatable relative to the container body in a predetermined angular range. The rotation of the cap relative to the container body is restricted so that the container body rotates along with the rotation of the cap when the rotation of the cap exceeds the predetermined angular range.

Abstract: A powder container is for use with an image forming apparatus, and the image forming apparatus includes a driving protrusion that is rotatable and that protrudes toward an upstream side in an insertion direction in which the powder container is inserted. The powder container includes a container body to store powder, a cap attached to the container body, and a transmitted structure provided on the cap to contact the driving protrusion. The transmitted structure extends outward from an outer circumference of the powder container. The cap is rotatable relative to the container body in a predetermined angular range. The rotation of the cap relative to the container body is restricted so that the container body rotates along with the rotation of the cap when the rotation of the cap exceeds the predetermined angular range.

Abstract: A powder container is for use with an image forming apparatus, and the image forming apparatus includes a driving protrusion that is rotatable and that protrudes toward an upstream side in an insertion direction in which the powder container is inserted. The powder container includes a container body to store powder, a cap attached to the container body, and a transmitted structure provided on the cap to contact the driving protrusion. The transmitted structure extends outward from an outer circumference of the powder container. The cap is rotatable relative to the container body in a predetermined angular range. The rotation of the cap relative to the container body is restricted so that the container body rotates along with the rotation of the cap when the rotation of the cap exceeds the predetermined angular range.

Abstract: A powder container is for use with an image forming apparatus, and the image forming apparatus includes a driving protrusion that is rotatable and that protrudes toward an upstream side in an insertion direction in which the powder container is inserted. The powder container includes a container body to store powder, a cap attached to the container body, and a transmitted structure provided on the cap to contact the driving protrusion. The transmitted structure extends outward from an outer circumference of the powder container. The cap is rotatable relative to the container body in a predetermined angular range. The rotation of the cap relative to the container body is restricted so that the container body rotates along with the rotation of the cap when the rotation of the cap exceeds the predetermined angular range.

Abstract: A powder container is for use with an image forming apparatus, and the image forming apparatus includes a driving protrusion that is rotatable and that protrudes toward an upstream side in an insertion direction in which the powder container is inserted. The powder container includes a container body to store powder, a cap attached to the container body, and a transmitted structure provided on the cap to contact the driving protrusion. The transmitted structure extends outward from an outer circumference of the powder container. The cap is rotatable relative to the container body in a predetermined angular range. The rotation of the cap relative to the container body is restricted so that the container body rotates along with the rotation of the cap when the rotation of the cap exceeds the predetermined angular range.

Abstract: A powder container is insertable in an image forming apparatus. The powder container includes a plurality of transmitted surfaces, at least one of the transmitted surfaces being configured to contact a first protrusion of the image forming, apparatus, the first protrusion being rotatable and protruding toward an upstream side in an insertion direction in which the powder container is inserted. The transmitted surfaces stand outward from an outer circumference of the powder container so that one of the transmitted surfaces is connected to another transmitted surface adjacent to the one of the transmitted surfaces by an inclined surface.

Abstract: A powder container is insertable in an image forming apparatus. The powder container includes a plurality of transmitted surfaces, at least one of the transmitted surfaces being configured to contact a first protrusion of the linage forming apparatus, the first protrusion being rotatable and protruding toward an upstream side in an insertion direction in which the powder container is inserted. The transmitted surfaces stand outward from an outer circumference of the powder container so that one of the transmitted surfaces is connected to another transmitted surface adjacent to the one of the transmitted surfaces by an inclined surface.

Abstract: A powder container is insertable in an image forming apparatus, and includes a main-body interlocking portion that is rotatable and protrudes toward an upstream side in an insertion direction in which the powder container is inserted, the image forming apparatus including an identifier protrusion that protrudes toward the upstream side in the insertion direction to identify a type of the powder container. The powder container includes a container interlocking portion configured to interlock with the main-body interlocking portion; and an interlocked portion configured to interlock with the identifier protrusion. The interlocked portion is provided in a front end of the powder container in the insertion direction. The container interlocking portion stands outward from an outer circumference of the powder container. The container interlocking portion and the interlocked portion are rotated integrally.

Abstract: A powder container is insertable in an image forming apparatus, and includes a main-body interlocking portion that is rotatable and protrudes toward an upstream side in an insertion direction in which the powder container is inserted, the image forming apparatus including an identifier protrusion that protrudes toward the upstream side in the insertion direction to identify a type of the powder container. The powder container includes a container interlocking portion configured to interlock with the main-body interlocking portion; and an interlocked portion configured to interlock with the identifier protrusion. The interlocked portion is provided in a front end of the powder container in the insertion direction. The container interlocking portion stands outward from an outer circumference of the powder container. The container interlocking portion and the interlocked portion are rotated integrally.

Abstract: An image forming apparatus includes a developer conveyance device to transport developer, using a positive-displacement pump to alternately generate positive pressure and negative pressure by changing a volume of an internal space thereof, a destination developer container to which the developer conveyance device transports developer, a sensor provided to the destination developer container, to detect developer in the destination developer container, and a controller to control the positive-displacement pump according to a detection result generated by the sensor. The controller disabled detection of developer by the sensor in a non-detection period that starts from a stop of the positive-displacement pump.

Abstract: A developing device includes a developer bearer to carry, by rotation, developer including toner and magnetic carrier to a development range facing a latent image bearer to bear a latent image. The developer bearer includes a magnetic field generator having multiple magnetic poles and a cylindrical developing sleeve to rotate and bear developer on an outer circumferential surface thereof with magnetic force of the magnetic field generator disposed inside the developing sleeve. The developing sleeve receives development voltage including an AC component having a frequency of 2.0 kHz or lower, and a duty ratio of a component having a polarity opposite a toner normal charge polarity of the AC component is within a range from 4% to 20%.

Abstract: An image forming apparatus includes a developing device; a developer conveyance device including a developer container, a developer reservoir to receive developer discharged from the developer container, and a positive-displacement pump to discharge, from the developer reservoir, developer supplied to the developing device by alternately generating positive pressure and negative pressure due to volume changes; and a controller to control driving of the positive-displacement pump. When the controller recognizes a developer end state of the developer container, the controller lowers a developer conveyance capability of the positive-displacement pump from a setting used before the developer end state is recognized.

Abstract: A developer conveyance device includes a developer reservoir for containing developer, and a positive-displacement pump to alternately generate positive pressure and negative pressure by varying a volume of space therein to transport developer from the developer reservoir to a destination. When Qp represents a volume of developer moved by a single pumping action of the pump, calculated by multiplying a maximum flow amount of the pump per unit time by an operation time of the pump; Qd represents a volume of developer contained in the developer reservoir; and Qe represents a volume of developer present in a virtual columnar space defined by vertically raising the developer outlet to a level of developer contained in the developer reservoir, either Qp>Qd or Qp>Qe is satisfied.

Abstract: A developer replenishing device includes a container mount to hold a developer container to contain developer used in image formation, an installation completion detector to detect completion of installation of the developer container in the container mount, a replaceable containing portion to contain developer, a conveyance channel to which the containing portion is removably connected and through which developer is transported from the developer container held in the container mount to the containing portion, and a conveyance pump to transport developer from the developer container through the conveyance channel to the containing portion. In a state in which the developer container is not held in the container mount according to a detection result by the installation completion detector, the conveyance pump transports developer from the conveyance channel to the containing portion.

Abstract: A developing device includes a developer bearer to carry, by rotation, developer including toner and magnetic carrier to a development range facing a latent image bearer, and the developer bearer includes a magnetic field generator having multiple magnetic poles and a cylindrical developing sleeve to rotate and bear developer on an outer circumferential face thereof with magnetic force of the magnetic field generator provided inside the developing sleeve. The developing sleeve receives developing bias voltage including an AC component, and includes a base to maintain a cylindrical shape of the developing sleeve and a low friction surface layer including a material lower in friction coefficient with toner than a material of the base.

Abstract: A driving force transmission mechanism includes a connection for integrally rotating a driving shaft on the driving source side and a driven shaft of a rotary member. The connection includes a tubular boss portion; and a fitting shaft portion fitted into the tubular boss portion. An inner shaft portion is provided in a projecting manner from bottom center of the tubular boss portion toward inside the tubular boss portion. An inner recessed portion into which the inner shaft portion fits is provided in center of a leading edge plane for fitting of the fitting shaft portion. Micro gaps are provided between an inner surface of the tubular boss portion and an outer surface of the fitting shaft portion and between an inner surface of the inner recessed portion and an outer surface of the inner shaft portion.

Abstract: A developing device includes a developer bearer to carry, by rotation, developer including toner and magnetic carrier to a development range facing a latent image bearer to bear a latent image. The developer bearer includes a magnetic field generator having multiple magnetic poles and a cylindrical developing sleeve to rotate and bear developer on an outer circumferential surface thereof with magnetic force of the magnetic field generator disposed inside the developing sleeve. The developing sleeve receives development voltage including an AC component having a frequency of 2.0 kHz or lower, and a duty ratio of a component having a polarity opposite a toner normal charge polarity of the AC component is within a range from 4% to 20%.

Abstract: An image forming apparatus includes a developer conveyance device to transport developer, using a positive-displacement pump to alternately generate positive pressure and negative pressure by changing a volume of an internal space thereof, a destination developer container to which the developer conveyance device transports developer, a sensor provided to the destination developer container, to detect developer in the destination developer container, and a controller to control the positive-displacement pump according to a detection result generated by the sensor. The controller disabled detection of developer by the sensor in a non-detection period that starts from a stop of the positive-displacement pump.

Abstract: A developing device includes a developer bearer to carry, by rotation, developer including toner and magnetic carrier to a development range facing a latent image bearer, and the developer bearer includes a magnetic field generator having multiple magnetic poles and a cylindrical developing sleeve to rotate and bear developer on an outer circumferential face thereof with magnetic force of the magnetic field generator provided inside the developing sleeve. The developing sleeve receives developing bias voltage including an AC component, and includes a base to maintain a cylindrical shape of the developing sleeve and a low friction surface layer including a material lower in friction coefficient with toner than a material of the base.