Abstract: An image forming apparatus includes a rotatable photosensitive member; a charging portion, an exposure portion, a developing member, a transfer unit, a contact and separation portion, a charging voltage applying portion, a detecting portion, and a controller. The controller is capable of executing an operation in an image forming mode and an operation in a detecting mode. The controller carries out control so that a charging current flowing through a charging portion during charging of the photosensitive member in the operation in the detecting mode is lower than a charging current flowing through the charging portion during charging of the photosensitive member in the operation in the image forming mode.

Abstract: In a toner cartridge configured such that, by rotating a toner housing portion relative to a shutter in a state in which a first portion-to-be-engaged is engaged to a first engaging portion of a developing unit, relative positions of a cover and the shutter are displaced from first relative position, in which a closing portion opposes a second opening, to second relative position, in which the interior of the toner housing portion communicates with the developing unit through a first opening and the second opening, and a second portion-to-be-engaged is engaged to a second engaging portion of the developing unit, thereby being attached to the developing unit, a biasing member is provided in order to exert a biasing force for generating relative rotation between the cover and the shutter in a direction for displacing the relative positions thereof from the second relative position to the first relative position.

Abstract: In a toner cartridge configured such that, by rotating a toner housing portion relative to a shutter in a state in which a first portion-to-be-engaged is engaged to a first engaging portion of a developing unit, relative positions of a cover and the shutter are displaced from first relative position, in which a closing portion opposes a second opening, to second relative position, in which the interior of the toner housing portion communicates with the developing unit through a first opening and the second opening, and a second portion-to-be-engaged is engaged to a second engaging portion of the developing unit, thereby being attached to the developing unit, a biasing member is provided in order to exert a biasing force for generating relative rotation between the cover and the shutter in a direction for displacing the relative positions thereof from the second relative position to the first relative position.

Abstract: A nip portion is formed between a transfer member and an image bearing member. During an image transfer operation, a first transfer voltage is applied so that a first charging voltage is applied to the surface of the image bearing member forming the nip portion. Before paper enters, a second transfer voltage is applied so that a third charging voltage is applied to the surface of the image bearing member forming the nip portion. A void is formed by the image bearing member, the transfer member and the paper within the nip portion. Before an image transfer operation and the void is formed, one of the first and second transfer voltages and a third transfer voltage is applied so that a second charging voltage having a same polarity as the first charging voltage and being lower in absolute value is applied to the surface of the image bearing member.

Abstract: A nip for holding paper is formed between a transfer member and an image bearing member. During an image transfer operation, a first transfer voltage is applied thereto so that a first charging voltage is applied to the surface of the image bearing member forming the nip portion. Before paper enters thereto, a second transfer voltage is applied thereto so that a third charging voltage is applied to the surface of the image bearing member forming the nip portion. A void is formed by the image bearing member, the transfer member and the paper within the nip. Before an image transfer operation and the void is formed, one of the first, second and third transfer voltages is applied so that the second charging voltage having a same polarity as the first charging voltage and being lower in absolute value is applied to the surface of the image bearing member.

Abstract: A developing apparatus, a cartridge, and an image forming apparatus in which, in a longitudinal direction, an edge portion of a carrying portion is disposed so as to be positioned outside an inner edge portion of an edge portion sealing member, and inside an outer edge portion of the edge portion sealing member. An edge portion of the restricting member is disposed so as to be positioned outside the edge portion of the carrying portion, and inside the outer edge portion of the edge portion sealing member.

Abstract: An image forming apparatus operable in a mode of forming an image using only a part of image forming stations. In the mode, a developing device contacts an image bearing member in a part of the image forming stations, and the developing device is spaced from the image bearing member in the rest of the image forming stations. The contact pressure between the image bearing member and a transferring device is made smaller in the rest than in the part. The image forming operation in the mode is executed while the image bearing members of the part and the rest are rotated. A controller is configured such that when the operation in the mode is continuously executed for a time period longer than a predetermined period, the contact pressure in the rest is made larger than the above-mentioned smaller contact pressure.

Abstract: A developing apparatus, a cartridge, and an image forming apparatus in which, in a longitudinal direction, an edge portion of a carrying portion is disposed so as to be positioned outside an inner edge portion of an edge portion sealing member, and inside an outer edge portion of the edge portion sealing member. An edge portion of the restricting member is disposed so as to be positioned outside the edge portion of the carrying portion, and inside the outer edge portion of the edge portion sealing member.

Abstract: At an end, in a longitudinal direction, of an opening in a container containing a magnetic developer, an overlap portion is provided in which a developer bearing member, a regulating member, a sealing member, and the container are arranged so as to sequentially contact one another in a direction orthogonal to a rotation axis direction. A magnetic field generating member provided inside the developer bearing member has a first area where a value of a magnetic flux density is a predetermined value in the rotation axis direction and a second area including a local minimum portion in which the value is a minimum value, within a range from an end of the second area connected to the first area to an outer end of the overlap portion in the rotation axis direction.

Abstract: A configuration in which an opening is covered with a plurality of partition members is provided, and timings of causing the partition members to move are differentiated, so that torque is reduced.

Abstract: Provided is a developer container, including: a frame body having an opening; a sealing member configured to seal the opening; an unsealing member configured to unseal the opening by moving the sealing member and accommodated inside the frame body; and a part of the sealing member peelably bonded to an outer peripheral edge of the opening on an opposite side of the unsealing member with respect to the opening.

Abstract: The disclosed structure includes a belt-shaped conveying member configured to convey developer. The conveying member includes a partitioning portion, which is a partition for developer contained in a casing with respect to a conveying direction in which the developer is conveyed, wherein, when the developer container is new, a first developer amount which is an amount of the developer contained at an upstream side that is upstream of the partitioning portion in the conveying direction, is larger than a second developer amount which is an amount of the developer contained at a downstream side that is downstream of the partitioning portion in the conveying direction.

Abstract: An image forming apparatus operable in a mode of forming an image using only a part of image forming stations. In the mode, a developing device contacts an image bearing member in a part of the image forming stations, and the developing device is spaced from the image bearing member in the rest of the image forming stations. The contact pressure between the image bearing member and a transferring device is made smaller in the rest than in the part. The image forming operation in the mode is executed while the image bearing members of the part and the rest are rotated. A controller is configured such that when the operation in the mode is continuously executed for a time period longer than a predetermined period, the contact pressure in the rest is made larger than the above-mentioned smaller contact pressure.

Abstract: A developer container includes a container, provided with an opening and configured to accommodate a developer; a sealing member configured to cover the opening; and an unsealing member configured to unseal the opening by moving the sealing member. The sealing member opposes the container at a central opposing portion positioned in a central side and at an end opposing portion positioned at an end side with respect to a longitudinal direction of the unsealing member. The sealing member and the container are bonded to each other at bonding portion which is at least a part of the central opposing portion. The bonding force at the bonding portion of the central opposing portion is larger than a bonding force between the sealing member and the container at the end opposing portion.

Abstract: An image forming apparatus is operable in a mode of forming an image using only a part of image forming stations. In the mode, a developing device contacts an image bearing member in the part of the image forming stations, and the developing device is spaced from the image bearing member in the rest of the image forming stations. The contact pressure between the image bearing member and a transferring device is made smaller in the rest than in the part. The image forming operation in the mode is executed while the image bearing members of the part and the rest are rotated. A controller is configured such that when the operation in the mode is continuously executed for a time period longer than a predetermined period, the contact pressure in the rest is made larger than the above-mentioned smaller contact pressure.

Abstract: At an end, in a longitudinal direction, of an opening in a container containing a magnetic developer, an overlap portion is provided in which a developer bearing member, a regulating member, a sealing member, and the container are arranged so as to sequentially contact one another in a direction orthogonal to a rotation axis direction. A magnetic field generating member provided inside the developer bearing member has a first area where a value of a magnetic flux density is a predetermined value in the rotation axis direction and a second area including a local minimum portion in which the value is a minimum value, within a range from an end of the second area connected to the first area to an outer end of the overlap portion in the rotation axis direction.

Abstract: The disclosed structure includes a belt-shaped conveying member configured to convey developer. The conveying member includes a partitioning portion, which is a partition for developer contained in a casing with respect to a conveying direction in which the developer is conveyed, wherein, when the developer container is new, a first developer amount which is an amount of the developer contained at an upstream side that is upstream of the partitioning portion in the conveying direction, is larger than a second developer amount which is an amount of the developer contained at a downstream side that is downstream of the partitioning portion in the conveying direction.

Abstract: A configuration in which an opening is covered with a plurality of partition members is provided, and timings of causing the partition members to move are differentiated, so that torque is reduced.

Abstract: A developer container includes a container, provided with an opening and configured to accommodate a developer; a sealing member configured to cover the opening; and an unsealing member configured to unseal the opening by moving the sealing member. The sealing member opposes the container at a central opposing portion positioned in a central side and at an end opposing portion positioned at an end side with respect to a longitudinal direction of the unsealing member. The sealing member and the container are bonded to each other at bonding portion which is at least a part of the central opposing portion. The bonding force at the bonding portion of the central opposing portion is larger than a bonding force between the sealing member and the container at the end opposing portion.

Abstract: Provided is a developer container, including: a frame body having an opening; a sealing member configured to seal the opening; an unsealing member configured to unseal the opening by moving the sealing member and accommodated inside the frame body; and a part of the sealing member peelably bonded to an outer peripheral edge of the opening on an opposite side of the unsealing member with respect to the opening.