Process unit including first, second and third conveyance members for conveying developer
A cartridge including a rotatable image bearing member which bears a developer, a cleaning member for removing a developer remaining on a surface of the image bearing member, the cleaning member having a contact portion in contact with the surface of the image bearing member and a support portion which supports the contact portion, a developer recovering portion which recovers the developer removed by the cleaning member, a first conveyance member which is disposed inside the developer recovering portion and conveys the recovered developer in a rotation axis direction of the image bearing member, a second conveyance member which conveys the developer conveyed by the first conveyance member in a direction crossing the rotation axis direction toward a discharge port provided in the developer recovering portion, and a third conveyance member to convey the developer toward the center of the photosensitive drum in the rotational axis direction. The second conveyance member is disposed at an inner side of the contact portion of the cleaning member with respect to an end part of the contact portion of the cleaning member.
1. A process unit comprising:
a rotatable photosensitive drum configured to bear a developer;
a development unit including a developer accommodating chamber configured to accommodate the developer supplied from a developer supply portion provided in a developer cartridge and a development roller configured to develop an electrostatic image formed on the photosensitive drum with the developer supplied from the developer accommodating chamber;
a transfer roller configured to transfer a toner image developed on the photosensitive drum to a sheet;
a cleaning member configured to remove the developer remaining on a surface of the photosensitive drum, the cleaning member including a contact portion in contact with a surface of the photosensitive drum and a support portion configured to support the contact portion;
a developer recovering portion configured to recover the developer removed by the cleaning member;
a first developer conveyance path;
a second developer conveyance path;
a first conveyance member disposed in the first developer conveyance path and configured to convey the recovered developer in a rotation axis direction of the photosensitive drum from the developer recovering portion to the second developer conveyance path;
a second conveyance member disposed in the second developer conveyance path and configured to convey the recovered developer in a direction crossing the rotation axis direction to a discharge port in the second developer conveyance path through which the developer is conveyed to a waste-developer recovering portion provided in the developer cartridge; and
a third conveyance member configured to convey the recovered developer toward a center of the photosensitive drum in the rotation axis direction,
wherein, in a state that the process unit is attached to an apparatus main body of an image forming apparatus, in a section perpendicular to the axis of rotation of the photosensitive drum, (i) the transfer roller is located below the photosensitive drum, (ii) the second conveyance member is above the photosensitive drum, (iii) the second conveyance member conveys the recovered developer upward relative to a gravity direction, and (iv) the recovered developer is discharged from the discharge port to the waste-developer recovering portion,
wherein in the rotation axis direction, the second conveyance member is disposed in an inner side of the contact portion of the cleaning member with respect to an end part of the contact portion of the cleaning member, and
wherein the developer recovered by the cleaning member is conveyed by the third conveyance member and is then conveyed by the first conveyance member.
2. The process unit according to claim 1 , wherein each of the first conveyance member and the second conveyance member has a spiral portion configured to convey the developer.
3. The process unit according to claim 2 , wherein a pitch of the spiral portion of the second conveyance member is longer than a pitch of the spiral portion of the first conveyance member.
4. The process unit according to claim 2 , wherein a diameter of the spiral portion of the second conveyance member is larger than a diameter of the spiral portion of the first conveyance member.
5. The process unit according to claim 1 , wherein the third conveyance member has a sheet member configured to convey the developer to the first conveyance member.