Process cartridge and electrophotographic image forming apparatus

A process cartridge detachably mountable to a main body of an electrophotographic image forming apparatus, comprising:

• (a) an electrophotographic photosensitive member;
• (b) a charge member for charging said electrophotographic photosensitive member;
• (c) a support member for rotatably supporting longitudinal ends of said charge member and for regulating an outward shifting movement of said charge member in a longitudinal direction;
• and
• (d) a cartridge frame including a first mounting portion for mounting said electrophotographic photosensitive member, a second mounting portion for mounting said support member, a regulating portion for regulating a longitudinal outward shifting movement of said support member when said charge member is supported by said support member mounted on said second mounting portion, and a support portion for supporting a periphery of said regulating portion,
• wherein said regulating portion is transverse to the longitudinal direction, and a space is defined by said regulating portion and said support portion extending from the periphery of said regulating portion.

An electrophotographic image forming apparatus for forming an image on a recording medium, comprising:

• (a) a mounting means for detachably mounting a process cartridge onto a main body, said process cartridge including (i) an electrophotographic photosensitive member, (ii) a charge member for charging said electrophotographic photosensitive member, (iii) a support member for rotatably supporting longitudinal ends of said charge member and for regulating an outward shifting movement of said charge member in a longitudinal direction, and (iv) a cartridge frame having a first mounting portion for mounting said electrophotographic photosensitive member, a second mounting portion for mounting said support member, a regulating portion for regulating a longitudinal outward shifting movement of said support member when said charge member is supported by said support member mounted on said second mounting portion, and a support portion for supporting a periphery of said regulating portion,
• wherein said regulating portion is transverse to the longitudinal direction, and a space is defined by said regulating portion and said support portion extending from the periphery of said regulating portion;
• and
• (b) a convey means for conveying the recording medium.

A cartridge frame used in a process cartridge which includes an electrophotographic photosensitive drum, a charge roller for charging said electrophotographic photosensitive drum and comprising a charge roller shaft, and two charge roller bearings, each charge roller bearing rotatably supporting one longitudinal end of said charge roller and regulating an outward shifting movement of said charge roller in a longitudinal direction, each charge roller bearing comprising a thrust regulating portion, wherein said thrust regulating portion is integral with said charge roller bearing and slidingly contacts a sliding end surface of said charge roller shaft, the cartridge frame being detachably mountable to a main body of an electrophotographic image forming apparatus, said cartridge frame comprising:

• a waste toner containing portion;
• two side walls;
• two drum bearings each attached to one of said side walls and supporting one end of said electrophotographic photosensitive drum, each drum bearing comprising a boss and a bearing rib, wherein each boss is coaxial with the rotation axis of said electrophotographic photosensitive drum;
• two inner walls, spaced from said two side walls toward the interior of said cartridge frame;
• two guide members, each guide member guiding one of said charge roller bearings for vertical movement;
• two compression springs, each positioned between one of said guide members and one of said inner walls, wherein said charge roller is urged against said electrophotographic photosensitive drum via said charge roller bearings and said compression springs;
• and
• a vertical regulating rib for regulating an outward shifting movement in a longitudinal direction of said thrust regulating portion of said charge roller bearings when said charge member is supported by said charge roller bearings guided by said guide members, wherein said vertical regulating rib abuts said thrust regulating portion of said charge roller bearings to prevent axial movement of said charge roller;
• and
• a box-shaped rib comprising said vertical regulating rib and the following additional elements:
• a surface extending perpendicular to a longitudinal direction of said cartridge frame;
• a first rib extending substantially parallel with said surface;
• and
• a second rib extending perpendicular said first rib,
• wherein said vertical regulating rib extends perpendicular to said first rib and to the longitudinal direction,
• wherein said cartridge frame comprises a developing frame, and a cleaning frame housing said waste toner containing portion, said side walls, said drum bearings, said two compression springs, said two inner walls, said two guide members, said vertical regulating rib, and said box-shaped rib, wherein the width of said cartridge frame increases in steps from said waste toner containing portion toward the developing frame.

A process cartridge detachably mountable to a main body of an electrophotographic image forming apparatus, said cartridge frame comprising:

• an electrophotographic photosensitive drum;
• a charge roller for charging said electrophotographic photosensitive drum and comprising a charge roller shaft;
• two charge roller bearings, each charge roller bearing rotatably supporting one longitudinal end of said charge roller and regulating an outward shifting movement of said charge roller in a longitudinal direction, each charge roller bearing comprising a thrust regulating portion, wherein said thrust regulating portion is integral with said charge roller bearing and slidingly contacts a sliding end surface of said charge roller shaft;
• and
• a cartridge frame supporting said electrophotographic photosensitive drum, said a charge roller, and said charge roller bearings, said cartridge frame comprising:
• a waste toner containing portion;
• two side walls;
• two drum bearings each attached to one of said side walls and supporting one end of said electrophotographic photosensitive drum, each drum bearing comprising a boss and a bearing rib, wherein each boss is coaxial with the rotation axis of said electrophotographic photosensitive drum;
• two inner walls, spaced from said two side walls toward the interior of said cartridge frame;
• two guide members, each guide member guiding one of said charge roller bearings for vertical movement;
• two compression springs, each positioned between one of said guide members and one of said inner walls, wherein said charge roller is urged against said electrophotographic photosensitive drum via said charge roller bearings and said compression springs;
• a vertical regulating rib for regulating an outward shifting movement in a longitudinal direction of said thrust regulating portion of said charge roller bearings when said charge member is supported by said charge roller bearings guided by said guide members, wherein said vertical regulating rib abuts said thrust regulating portion of said charge roller bearings to prevent axial movement of said charge roller;
• and
• a box-shaped rib comprising said vertical regulating rib and the following additional elements:
• a surface extending perpendicular to a longitudinal direction of said cartridge frame;
• a first rib extending substantially parallel with said surface;
• and
• a second rib extending perpendicular said first rib,
• wherein said vertical regulating rib extends perpendicular to said first rib and to the longitudinal direction,
• wherein said cartridge frame comprises a developing frame, and a cleaning frame housing said waste toner containing portion, said side walls, said drum bearings, said compression springs, said two inner walls, said two guide members, said vertical regulating rib, and said box-shaped rib, wherein the width of said cartridge frame increases in steps from said waste toner containing portion toward the developing frame.