Image forming apparatus including a contact and separation mechanism

An image forming apparatus comprising:

• a plurality of photoreceptors;
• a primary transfer unit attachable to, and detachable from, an apparatus main body;
• and
• a unit lock that restricts the primary transfer unit from being detached from the apparatus main body, wherein:
• the primary transfer unit includes:
• a primary transfer belt to which toner images are transferred from the plurality of photoreceptors,
• a plurality of primary transfer rollers that are positioned, respectively, opposite the plurality of photoreceptors, with the primary transfer belt therebetween, and
• a contact and separation mechanism that brings the plurality of primary transfer rollers into contact with the plurality of photoreceptors and that separates the plurality of primary transfer rollers from the plurality of photoreceptors, and the contact and separation mechanism includes:
• a plurality of arm members that rotatably support the plurality of primary transfer rollers, respectively,
• a link member that shifts positions of the plurality of arm members by moving between different positions to bring the plurality of primary transfer rollers into contact with the plurality of photoreceptors and to separate the plurality of primary transfer rollers from the plurality of photoreceptors, the link member being movable back and forth in a direction perpendicular to an axial direction of the plurality of primary transfer rollers, and
• a grip to move the link member and detach the primary transfer unit from the apparatus main body, the grip being provided at one end of the link member, such that when a user moves, using the grip, the link member to a release position for separating all of the plurality of primary transfer rollers from the plurality of photoreceptors, the unit lock transitions from a locking state to an unlocking state, wherein
• the link member has a pusher,
• the unit lock has a push receiver that is pushed by the pusher, and
• in conjunction with the user's operation of moving the link member to the release position, the pusher pushes the push receiver to cause the unit lock to transition from the locking state to the unlocking state.

An image forming apparatus comprising:

• a plurality of photoreceptors;
• a primary transfer unit attachable to, and detachable from, an apparatus main body;
• and
• a unit lock that restricts the primary transfer unit from being detached from the apparatus main body, wherein:
• the primary transfer unit includes:
• a primary transfer belt to which toner images are transferred from the plurality of photoreceptors,
• a plurality of primary transfer rollers that are positioned, respectively, opposite the plurality of photoreceptors, with the primary transfer belt therebetween, and
• a contact and separation mechanism that brings the plurality of primary transfer rollers into contact with the plurality of photoreceptors and that separates the plurality of primary transfer rollers from the plurality of photoreceptors, the contact and separation mechanism includes:
• a plurality of arm members that rotatably support the plurality of primary transfer rollers, respectively,
• a link member that shifts positions of the plurality of arm members by moving between different positions to bring the plurality of primary transfer rollers into contact with the plurality of photoreceptors and to separate the plurality of primary transfer rollers from the plurality of photoreceptors, the link member being movable back and forth in a direction perpendicular to an axial direction of the plurality of primary transfer rollers, and
• a grip to move the link member and detach the primary transfer unit from the apparatus main body, the grip being provided at one end of the link member, such that when a user moves, using the grip, the link member to a release position for separating all of the plurality of primary transfer rollers from the plurality of photoreceptors, the unit lock transitions from a locking state to an unlocking state, and
• the unit lock includes:
• a locking hole provided in the apparatus main body,
• a lock pin provided on the primary transfer unit, the lock pin being movable back and forth to be engaged with the locking hole, and
• an urging member that urges the lock pin in such a direction as to separate the lock pin from the locking hole, wherein
• in conjunction with the user's operation of moving the link member to the release position, the urging member exerts an urging force to cause the unit lock to transition from the locking state to the unlocking state.