Abstract: An image forming apparatus including a first unit having an image bearing member, a second unit having a development member, an apparatus main body which includes an opening portion, an opening-closing member to open or close the opening portion, a first portion contacting with a part of the first unit to position the first unit to the apparatus main body, and a second portion arranged on an opposite side of the first portion with respect to the image bearing member, and a sandwiched unit movable between a first position at which the sandwiched unit is sandwiched between the first unit and the second portion and a second position at which the sandwiched unit is not sandwiched, wherein when the sandwiched unit is located at the first position, a part of the first unit is urged against the first portion by the sandwiched unit.

Abstract: An image forming apparatus including a first unit having an image bearing member, a second unit having a development member, an apparatus main body which includes an opening portion, an opening-closing member to open or close the opening portion, a first portion contacting with a part of the first unit to position the first unit to the apparatus main body, and a second portion arranged on an opposite side of the first portion with respect to the image bearing member, and a sandwiched unit movable between a first position at which the sandwiched unit is sandwiched between the first unit and the second portion and a second position at which the sandwiched unit is not sandwiched, wherein when the sandwiched unit is located at the first position, a part of the first unit is urged against the first portion by the sandwiched unit.

Abstract: Radius increased areas, radius decreased areas, and rotation stop areas are arranged in peripheral surfaces of first and second cams. In a state in which a portion in the peripheral surface of the first cam to which the first cam follower is contacting is positioned at an upstream end portion of the radius increased area, ?1 is a rotation amount of the first cam from the end portion needed until the first cam follower contacts the rotation stop area, and in a state in which a portion in the peripheral surface of the second cam to which the second cam follower is contacting is positioned at an upstream end portion of the radius increased area, ?2 is a rotation amount of the second cam from the end portion needed until the second cam follower contacts the rotation stop area. ?1<?2 is satisfied.

Abstract: An image forming apparatus includes a supporting member configured to support a developing unit and be movable between a first position and a second position, an opening/closing member configured to open and close an opening through which the developing unit passes when the developing unit is attached to or detached from the supporting member, and a restriction member configured to restrict a movement of the supporting member from a third position different from the first and second positions, wherein in case where the opening/closing member is opened when the supporting member is at the first position, the restriction member presses the supporting member to move to the third position, and in case where the opening/closing member is opened when the supporting member is at the second position, the restriction member presses the supporting member to move to the third position.

Abstract: A developer container includes a developer storage chamber that stores developer and includes an opening, a sealing member that seals the opening, an unsealing member that opens the opening by rotating such that the sealing member, a part of which is attached to the unsealing member, is peeled away, a stirring member that is attached to the unsealing member; and a regulating portion that regulates rotation of the unsealing member by contacting the stirring member. The regulating portion is provided to regulate the rotation of the unsealing member when the developer container receives an external force, and allow the unsealing member to rotate such that the opening is opened when the unsealing member receives driving power.

Abstract: An image forming apparatus includes a supporting member configured to support a developing unit and be movable between a first position and a second position, an opening/closing member configured to open and close an opening through which the developing unit passes when the developing unit is attached to or detached from the supporting member, and a restriction member configured to restrict a movement of the supporting member from a third position different from the first and second positions, wherein in case where the opening/closing member is opened when the supporting member is at the first position, the restriction member presses the supporting member to move to the third position, and in case where the opening/closing member is opened when the supporting member is at the second position, the restriction member presses the supporting member to move to the third position.

Abstract: A developer container includes a developer storage chamber that stores developer and includes an opening, a sealing member that seals the opening, an unsealing member that opens the opening by rotating such that the sealing member, a part of which is attached to the unsealing member, is peeled away, a stirring member that is attached to the unsealing member; and a regulating portion that regulates rotation of the unsealing member by contacting the stirring member. The regulating portion is provided to regulate the rotation of the unsealing member when the developer container receives an external force, and allow the unsealing member to rotate such that the opening is opened when the unsealing member receives driving power.

Abstract: A developer container includes a developer storage chamber that stores developer and includes an opening, a sealing member that seals the opening, an unsealing member that opens the opening by rotating such that the sealing member, a part of which is attached to the unsealing member, is peeled away, a stirring member that is attached to the unsealing member; and a regulating portion that regulates rotation of the unsealing member by contacting the stirring member. The regulating portion is provided to regulate the rotation of the unsealing member when the developer container receives an external force, and allow the unsealing member to rotate such that the opening is opened when the unsealing member receives driving power.

Abstract: A process cartridge attachable/detachable to/from an apparatus main body of an electrophotographic image forming apparatus is configured such that the photosensitive unit and the development unit are coupled with each other at both ends in a direction parallel to a rotational center axis line of the photosensitive drum. Guide units are provided at one end of the photosensitive unit and at one end of the development unit, which are separated from each other when an external force does not work on the process cartridge. When the process cartridge is subjected to an impact in a direction in which the development roller approaches the photosensitive drum, the guide units are brought into contact with each other while the development unit rotates relative to the link member, and guide the development unit in a direction in which the development roller separates from the photosensitive drum.

Abstract: A developer container includes a developer storage chamber that stores developer and includes an opening, a sealing member that seals the opening, an unsealing member that opens the opening by rotating such that the sealing member, apart of which is attached to the unsealing member, is peeled away, a stirring member that is attached to the unsealing member; and a regulating portion that regulates rotation of the unsealing member by contacting the stirring member. The regulating portion is provided to regulate the rotation of the unsealing member when the developer container receives an external force, and allow the unsealing member to rotate such that the opening is opened when the unsealing member receives driving power.

Abstract: A process cartridge attachable/detachable to/from an apparatus main body of an electrophotographic image forming apparatus is configured such that the photosensitive unit and the development unit are coupled with each other at both ends in a direction parallel to a rotational center axis line of the photosensitive drum. Guide units are provided at one end of the photosensitive unit and at one end of the development unit, which are separated from each other when an external force does not work on the process cartridge. When the process cartridge is subjected to an impact in a direction in which the development roller approaches the photosensitive drum, the guide units are brought into contact with each other while the development unit rotates relative to the link member, and guide the development unit in a direction in which the development roller separates from the photosensitive drum.

Abstract: An image forming apparatus to which a cartridge including first and second cartridge contacts is detachably mountable, includes: a guiding member for guiding the cartridge to a positioning portion provided in a main assembly of the image forming apparatus; a first main assembly contact contactable to the first cartridge contact when the cartridge is positioned partway toward the positioning portion and is positioned in the positioning portion; a second main assembly contact contactable to the second cartridge contact when the cartridge is positioned partway toward the positioning portion; a third main assembly contact contactable to the second cartridge contact only when the cartridge is positioned in the positioning portion; and a control portion for detecting presence or absence of the cartridge in the main assembly and a mounted state of the cartridge by being electrically connected with the first, second and third main assembly contacts.

Abstract: An image forming apparatus to which a cartridge including first and second cartridge contacts is detachably mountable, includes: a guiding member for guiding the cartridge to a positioning portion provided in a main assembly of the image forming apparatus; a first main assembly contact contactable to the first cartridge contact when the cartridge is positioned partway toward the positioning portion and is positioned in the positioning portion; a second main assembly contact contactable to the second cartridge contact when the cartridge is positioned partway toward the positioning portion; a third main assembly contact contactable to the second cartridge contact only when the cartridge is positioned in the positioning portion; and a control portion for detecting presence or absence of the cartridge in the main assembly and a mounted state of the cartridge by being electrically connected with the first, second and third main assembly contacts.