Developing cartridge capable of releasing meshing between gear and rack gear

A developing cartridge comprising:

• a casing configured to accommodate toner therein;
• a developing roller rotatable about a first axis extending in an axial direction, the developing roller being positioned at one end of the casing;
• a gear rotatable about a second axis extending in the axial direction;
• a developing electrode electrically connected to the developing roller;
• a rack gear movable from the one end of the casing toward another end of the casing opposite to the one end of the casing, the rack gear being movable in a direction from the one end of the casing toward the another end of the casing in accordance with rotation of the gear by meshing with the gear, the rack gear including a protrusion;
• a cover covering at least a portion of the rack gear, the cover having an opening through which the developing electrode is exposed to an outside;
• and
• a cam movable from a first position to a second position, the second position being farther away from the casing than the first position is from the casing in the axial direction, the cam having:
• a first cam surface having a first edge and a second edge, the second edge being positioned farther away from the casing than the first edge is from the casing in the axial direction, the first cam surface being inclined so that the first edge is positioned downstream relative to the second edge in a moving direction of the protrusion, the first cam surface causing the cam to move from the first position to the second position by engaging with the protrusion, the first cam surface being positioned outside of a movement locus of the protrusion in a case where the cam is at the second position;
• and
• a second cam surface movable together with the first cam surface, the second cam surface being positioned farther away from the casing than the first cam surface is from the casing in the axial direction, the second cam surface being movable while contacting the developing electrode, the second cam surface having a fifth first edge and a sixth second edge, the sixth second edge of the second cam surface being positioned farther away from the casing than the fifth first edge of the second cam surface is from the casing in the axial direction, the second cam surface being inclined so as to protrude toward the opening in a direction from the sixth second edge of the second cam surface toward the fifth first edge of the second cam surface.

A developing cartridge comprising:

• a casing configured to accommodate toner therein;
• a developing roller rotatable about a first axis extending in an axial direction, the developing roller being positioned at one end of the casing;
• a gear rotatable about a second axis parallel with the first axis;
• a rack gear meshing with the gear, the rack gear being movable in a direction from the one end of the casing toward another end of the casing opposite to the one end of the casing;
• a cam movable from a first position to a second position, the second position being farther away from the casing than the first position is from the casing in the axial direction, the cam including a protrusion;
• a spring urging the cam from the first position toward the second position;
• a cover having an opening;
• and
• a developing electrode electrically connected to the developing roller, the developing electrode being movable together with the cam, the developing electrode having a second cam surface, the second cam surface having a fifth first edge and a sixth second edge, the sixth second edge being positioned farther away from the casing than the fifth first edge is from the casing in the axial direction, the second cam surface being inclined so as to protrude toward the opening in a direction from the sixth second edge toward the fifth first edge,
• the rack gear having:
• a first holding surface contacting the protrusion to hold the cam at the first position;
• and
• a second holding surface contacting the protrusion to hold the cam at the second position.

A developing cartridge comprising:

• a casing configured to accommodate toner therein;
• a developing roller rotatable about a first axis extending in an axial direction, the developing roller being positioned at a first end of the casing;
• a developing electrode electrically connected to the developing roller;
• a gear rotatable about a second axis parallel with the first axis;
• a rack gear meshing with the gear, the rack gear being movable in a direction extending between the first end of the casing and a second end of the casing opposite to the first end of the casing, the rack gear including a protrusion;
• and
• a cam movable between a first position and a second position, the cam having:
• a first cam surface configured to engage the protrusion to selectively move the cam between the first and second positions in response to movement of the rack gear.

A developing cartridge comprising:

• a casing configured to accommodate toner therein;
• a developing roller rotatable about a first axis extending in an axial direction, the developing roller being positioned at a first end of the casing;
• a developing electrode electrically connected to the developing roller;
• a gear rotatable about a second axis parallel with the first axis;
• a rack gear meshing with the gear, the rack gear including a protrusion;
• and
• a cam movable from a first position to a second position, the cam having a first cam surface contacting the protrusion in a case where the cam is at the first position, the first cam surface causing the cam to move from the first position to the second position in a case where the rack gear moves in a direction extending between the first end of the casing and a second end of the casing opposite to the first end of the casing.

A developing cartridge comprising:

• a casing configured to accommodate toner therein;
• a developing roller rotatable about a first axis extending in an axial direction, the developing roller being positioned at one end of the casing;
• a developing electrode electrically connected to the developing roller;
• a gear rotatable about a second axis parallel with the first axis;
• a rack gear meshing with the gear and being movable in a direction extending between the one end of the casing and another end of the casing opposite the one end of the casing;
• and
• a cam movable from a first position to a second position, the cam being movable from the first position to the second position to move the developing electrode in a case where the rack gear moves in the direction extending between the one end of the casing and the another end of the casing opposite to the one end of the casing.