Process cartridge, method for assembling process cartridge and image forming apparatus

A toner frame used in a process cartridge removably mountable onto a main body of an electrophotographic image forming apparatus;

• the main body of the electrophotographic image forming apparatus including a plate-like spring to be electrically contacted with an electrophotographic photosensitive drum in the process cartridge for earthing the electrophotographic photosensitive drum, a fixed member for shifting a protection cover of the process cartridge for protecting the electrophotographic photosensitive drum, a laser beam emitting member for emitting a laser beam to irradiate the electrophotographic photosensitive drum, a laser shutter capable of assuming a position for shutting an optical path from the laser beam emitting member to the electrophotographic photosensitive drum, and a retracting member for retracting the laser shutter from the position shutting the optical path;
• the process cartridge including an electrophotographic photosensitive drum;
• a rotatable developing roller for supplying toner to the electrophotographic photosensitive drum for developing a latent image formed on the electrophotographic photosensitive drum;
• a charge roller abutted to the electrophotographic photosensitive drum for charging the electrophotographic photosensitive drum;
• a cleaning blade abutted to the electrophotographic photosensitive drum for removing residual toner from the electrophotographic photosensitive drum;
• a cleaning frame in which the electrophotographic photosensitive drum, the charge roller, and the cleaning blade are disposed;
• a developing frame, rockably connectable with the cleaning frame, in which the rotatable developing roller is disposed;
• a protection cover for protecting the electrophotographic photosensitive drum, the protection cover capable of assuming a protection position wherein a transfer area on the electrophotographic photosensitive drum is covered, the transfer area being an area where the toner image developed on the electrophotographic photosensitive drum is transferred to a recording medium, and an open position wherein the transfer area is not covered, the protection cover being supported by an arm portion thereof that is attached to the cleaning frame;
• a torsion coil spring, spanned between the arm portion and the cleaning frame for applying an urging force to the protection cover to urge the protection cover toward the protection position;
• a link member provided adjacent to one end of the electrophotographic photosensitive drum in the axial direction thereof, the link member capable of rotating about a shaft to rotate the arm portion supporting the protection cover for shifting the protection cover from the protection position to the open position, wherein, in the process of mounting the process cartridge to the main body, the link member abuts the fixed member to thereby shift the protection cover from the protection position to the open position against the urging force of the torsion coil spring;
• a drum earth contact for earthing the electrophotographic photosensitive drum by abutting the plate-like spring, the drum earth contact being provided adjacent to the end of the electrophotographic photosensitive drum that the link member is provided adjacent to and further being provided on a drum shaft for supporting the electrophotographic photosensitive drum on the cleaning frame, wherein the drum earth contact protrudes outside of the cleaning frame and abuts the plate-like spring when the process cartridge is mounted to the main body;
• an abutment portion, provided adjacent to another end of the electrophotographic photosensitive drum opposite the one end that the drum earth contact is provided adjacent to in the axial direction thereof, for abutting the retracting member, the abutment portion abutting the retracting member in the process of mounting the process cartridge onto the main body;
• wherein the process cartridge is mounted onto the main body in a direction intersecting the axial direction of the electrophotographic photosensitive drum;
• said toner frame comprising:
• a toner containing portion for containing toner to be used by the rotatable developing roller for developing a latent image formed on the electrophotographic photosensitive drum;
• and
• a plurality of elongated ribs formed on an outer surface of said toner containing portion along the axial direction of the electrophotographic photosensitive drum, said plurality of elongated ribs being used as a grip for gripping the process cartridge when removably mounting the process cartridge onto the main body of the electrophotographic image forming apparatus,
• wherein, when said toner frame is connected with the developing frame to construct the process cartridge, a longitudinal center of said plurality of elongated ribs is offset in the axial direction of the electrophotographic photosensitive drum from a longitudinal midpoint of the electrophotographic photosensitive drum toward the end of the electrophotographic photosensitive drum adjacent which the link member and the drum earth contact are disposed.

A process cartridge removably mountable onto a main body of an electrophotographic image forming apparatus including a resilient earth contact to be electrically contacted with an electrophotographic photosensitive drum in said process cartridge for earthing said electrophotographic photosensitive drum, and a fixed member for opening a protection cover of said process cartridge for protecting said electrophotographic photosensitive drum, said process cartridge comprising:

• an electrophotographic photosensitive drum;
• a rotatable developing roller for supplying toner to said electrophotographic photosensitive drum for developing a latent image formed thereon;
• a charging roller abutted to said electrophotographic photosensitive drum for charging said electrophotographic photosensitive drum;
• a cleaning blade abutted to said electrophotographic photosensitive drum for removing residual toner from said electrophotographic photosensitive drum;
• a protection cover for protecting said electrophotographic photosensitive drum, said protection cover capable of assuming a protection position wherein a transfer area of said electrophotographic photosensitive drum is covered, said transfer area being an area where the toner image developed on said electrophotographic photosensitive drum is transferred to a recording medium, and an open position wherein said transfer area is not covered;
• an urging member for applying an urging force to said protection cover so as to urge said protection cover toward the protection position;
• a protection cover shift member disposed adjacent one end of said electrophotographic photosensitive drum in an axial direction thereof, wherein said protection cover shift member abuts the fixed member for shifting said protection cover from the protection position to the open position against the urging force in the process of mounting said process cartridge onto the main body of the electrophotographic image forming apparatus;
• a drum earthing member disposed adjacent said one end of said electrophotographic photosensitive drum that said protection cover shift member is disposed adjacent to, wherein said drum earthing member abuts the resilient earth contact in the process of mounting said process cartridge onto the main body of said electrophotographic image forming apparatus;
• and
• a toner frame having a toner containing portion for containing toner to be used by said rotatable developing roller for developing the latent image formed on said electrophotographic photosensitive drum, and a grip formed on an outer surface of said toner containing portion for gripping said toner frame upon mounting and dismounting of said process cartridge respectively onto and from the main body of the electrophotographic image forming apparatus,
• wherein, when said process cartridge is in an assembled state, a center of said grip is offset in the axial direction of said electrophotographic photosensitive drum from a longitudinal midpoint of said electrophotographic photosensitive drum toward said one end of said electrophotographic photosensitive drum at which said protection cover shift member and said drum earthing member are disposed adjacent to, and
• wherein said process cartridge is mounted onto the main body of the electrophotographic image forming apparatus in a direction intersecting the axial direction of said electrophotographic photosensitive drum.

A process cartridge removably mountable onto a main body of an electrophotographic image forming apparatus, the main body of the electrophotographic image forming apparatus including a resilient earth contact to be electrically contacted with an electrophotographic photosensitive drum in said process cartridge for earthing said electrophotographic photosensitive drum, and a fixed member for opening a protection cover of said process cartridge for protecting said electrophotographic photosensitive drum, a laser beam emitting member for emitting a laser beam to irradiate said electrophotographic photosensitive drum, a laser shutter for shutting an optical path from the laser beam emitting member to said electrophotographic photosensitive drum, and a retracting member for retracting the laser shutter from the position shutting the optical path, said process cartridge comprising:

• an electrophotographic photosensitive drum;
• a rotatable developing roller for supplying toner to said electrophotographic photosensitive drum for developing a latent image formed thereon;
• a charging roller abutted to said electrophotographic photosensitive drum for charging said electrophotographic photosensitive drum;
• a cleaning blade abutted to said electrophotographic photosensitive drum for removing residual toner from said electrophotographic photosensitive drum;
• a cleaning frame in which said electrophotographic photosensitive drum, said charging roller, and said cleaning blade are disposed;
• a developing frame in which said rotatable developing roller is disposed, said developing frame being rockably connectable with said cleaning frame;
• a protection cover for protecting said electrophotographic photosensitive drum, said protection cover capable of assuming a protection position wherein a transfer area on said electrophotographic photosensitive drum is covered, said transfer area being an area where the toner image developed on said electrophotographic photosensitive drum is transferred to a recording medium, and an open position wherein said transfer area is not covered, said protection cover being supported by an arm portion attached to said cleaning frame;
• a torsion coil spring spanned between said arm portion and said cleaning frame for applying an urging force to said protection cover so as to urge said protection cover toward the protection position;
• a link member provided adjacent to one end of said electrophotographic photosensitive drum in an axial direction thereof, said link member capable of rotating about a shaft to rotate said arm portion supporting said protection cover for shifting said protection cover from the protection position to the open position, said link member abutting the fixed member in the process of mounting said process cartridge onto the main body of the electrophotographic imaging forming apparatus to thereby shift said protection cover from the protection position to the open position against the urging force of said torsion coil spring;
• a drum earth contact, disposed adjacent to said one end of said electrophotographic photosensitive drum that said link member is disposed adjacent to, for earthing said electrophotographic photosensitive drum by abutting the resilient earth contact, said drum earth contact being provided on a drum shaft for supporting said electrophotographic photosensitive drum in said cleaning frame, said drum earth contact protruding beyond an outside side surface of said cleaning frame and abutting the resilient earth contact in the process of mounting said process cartridge onto the main body of the electrophotographic image forming apparatus;
• an abutment portion disposed adjacent to an end of said electrophotographic photosensitive drum opposite said one end that said drum earth contact and said link member are disposed adjacent to in the axial direction thereof, said abutment portion abutting the retracting member for retracting the laser shutter from the position shutting the optical path in the process of mounting said process cartridge onto the main body of the electrophotographic image forming apparatus;
• and
• a toner frame, connectable with said developing frame, having a toner containing portion for containing toner to be used by said rotatable developing roller for developing the latent image formed on said electrophotographic photosensitive drum, and a plurality of elongated ribs formed on an outer surface of said toner containing portion along the axial direction of said electrophotographic photosensitive drum, said plurality of elongated ribs being used as a grip for gripping said process cartridge when removably mounting said process cartridge onto the main body of the electrophotographic image forming apparatus,
• wherein, when said toner frame is connected with said developing frame to construct said process cartridge, a longitudinal center of said plurality of elongated ribs is offset in the axial direction of said electrophotographic photosensitive drum from a longitudinal midpoint of said electrophotographic photosensitive drum toward said one end of said electrophotographic photosensitive drum that said drum earth contact and said link member are disposed, and
• wherein said process cartridge is removably mounted onto the main body of the electrophotographic image forming apparatus in a direction intersecting the axial direction of said electrophotographic photosensitive drum.

An assembling method for assembling a process cartridge removably mountable onto a main body of an electrophotographic image forming apparatus including a resilient earth contact to be electrically contacted with an electrophotographic photosensitive drum in the process cartridge for earthing the electrophotographic photosensitive drum, and a fixed member for opening a protection cover for protecting the electrophotographic photosensitive drum, said assembling method comprising the steps of:

• preparing a cleaning frame provided with an electrophotographic photosensitive drum;
• a charging roller abutted to the electrophotographic photosensitive drum for charging the electrophotographic photosensitive drum;
• a cleaning blade abutted to the electrophotographic photosensitive drum for removing residual toner from the electrophotographic photosensitive drum;
• a protection cover for protecting the electrophotographic photosensitive drum, the protection cover capable of assuming a protection position wherein a transfer area on the electrophotographic photosensitive drum is covered, the transfer area being an area where a toner image developed on the electrophotographic photosensitive drum is transferred to a recording medium, and an open position wherein the transfer area is not covered;
• an urging member for applying an urging force to the protection cover so as to urge the protection cover toward the protection position;
• a protection cover shift member disposed adjacent one end of the electrophotographic photosensitive drum in an axial direction thereof, wherein the protection cover shift member abuts the fixed member for shifting the protection cover from the protection position to the open position against the urging force in the process of mounting the process cartridge onto the main body of the electrophotographic image forming apparatus;
• a drum earthing member disposed adjacent to the end of the electrophotographic photosensitive drum that the protection cover shift member is disposed adjacent to, wherein the drum earthing member abuts the resilient earth contact when the process cartridge is mounted onto the main body of the electrophotographic image forming apparatus;
• preparing a developing frame provided with a rotatable developing roller for developing a latent image formed on the electrophotographic photosensitive drum by supplying toner to the electrophotographic photosensitive drum;
• preparing a toner frame provided with a toner containing portion for containing the toner to be used by the developing roller for developing the latent image formed on the electrophotographic photosensitive drum, and a grip formed on an outer surface of the toner containing portion for gripping the toner frame upon mounting and dismounting of the process cartridge respectively onto and from the main body of the electrophotographic image forming apparatus, a center of the grip being offset in the axial direction of the electrophotographic photosensitive drum from a longitudinal midpoint of the electrophotographic photosensitive drum toward the one end of the electrophotographic photosensitive drum that the protection cover shift member and the drum earthing member are disposed when the toner frame is assembled as part of the process cartridge;
• connecting the developing frame and the toner frame;
• and
• connecting the joined developing frame and toner frame rockably to the cleaning frame,
• wherein the process cartridge is removably mounted onto the main body of the electrophotographic image forming apparatus in a direction intersecting with the axial direction of the electrophotographic photosensitive drum.

An assembling method for assembling a process cartridge removably mountable onto a main body of an electrophotographic image forming apparatus, the main body of the electrophotographic image forming apparatus including a resilient earth contact to be electrically contacted with an electrophotographic photosensitive drum in the process cartridge for earthing the electrophotographic photosensitive drum, and a fixed member for opening a protection cover for protecting the electrophotographic photosensitive drum, a laser beam emitting member for emitting a laser beam to irradiate the electrophotographic photosensitive drum, a laser shutter capable of assuming a position for shutting an optical path from the laser beam emitting member to the electrophotographic photosensitive drum, and a retracting member for retracting the laser shutter from the position shutting the optical path, said assembling method comprising the steps of:

• preparing a cleaning frame provided with an electrophotographic photosensitive drum;
• a charging roller abutted to the electrophotographic photosensitive drum for charging the electrophotographic photosensitive drum;
• a cleaning blade abutted to the electrophotographic photosensitive drum for removing residual toner from the electrophotographic photosensitive drum;
• a protection cover for protecting the electrophotographic photosensitive drum, the protection cover capable of assuming a protection position wherein a transfer area on the electrophotographic photosensitive drum is covered, the transfer area being an area where a toner image developed on the electrophotographic photosensitive drum is transferred to a recording medium, and an open position wherein the transfer area is not covered, the protection cover being supported by an arm portion attached to the cleaning frame;
• a torsion coil spring spanned between the arm portion and the cleaning frame for applying an urging force to the protection cover so as to urge the protection cover toward the protection position;
• a link member disposed adjacent to one end of the electrophotographic photosensitive drum in an axial direction thereof, the link member capable of rotating about a shaft to rotate the arm portion supporting the protection cover for shifting the protection cover from the protection position to the open position, the link member abutting the fixed member in the process of mounting the process cartridge onto the main body of the electrophotographic image forming apparatus to thereby shift the protection cover from the protection position to the open position against the urging force of the torsion coil spring;
• a drum earth contact, disposed adjacent to the one end of the electrophotographic photosensitive drum that the link member is disposed adjacent to, for earthing the electrophotographic photosensitive drum by abutting the resilient earth contact, the drum earth contact being provided on a drum shaft for supporting the electrophotographic photosensitive drum in the cleaning frame, the drum earth contact protruding beyond an outside side surface of the cleaning frame and abutting the resilient earth contact in the process of mounting the process cartridge onto the main body of the electrophotographic image forming apparatus;
• an abutment portion disposed adjacent to an end of the electrophotographic photosensitive drum opposite the one end that the drum earth contact and the link member are disposed adjacent to in the axial direction thereof, the abutment portion abutting the retracting member for retracting the laser shutter from the position shutting the optical path in the process of mounting the process cartridge onto the main body of the electrophotographic image forming apparatus;
• preparing a developing frame provided with a rotatable developing roller for developing a latent image formed on the electrophotographic photosensitive drum by supplying toner to the electrophotographic photosensitive drum;
• preparing a toner frame that is connectable with the developing frame and is provided with a toner containing portion for containing the toner to be used by the developing roller for developing the latent image formed on the electrophotographic photosensitive drum;
• and a plurality of elongated ribs formed on an outer surface of the toner containing portion along the axial direction of the electrophotographic photosensitive drum, the plurality of elongated ribs being used as a grip for gripping the process cartridge when removably mounting the process cartridge onto the main body of the electrophotographic image forming apparatus, wherein, when the toner frame is connected with the developing frame to construct the process cartridge, a longitudinal center of the plurality of elongated ribs is offset in the axial direction of the electrophotographic photosensitive drum from a longitudinal midpoint of the electrophotographic photosensitive drum toward the one end of the electrophotographic photosensitive drum that the drum earth contact and the link member are disposed adjacent to;
• connecting the developing frame and the toner frame;
• and
• connecting the joined developing frame and toner frame rockably to the cleaning frame,
• wherein the process cartridge is removably mounted onto the main body of the electrophotographic image forming apparatus in a direction intersecting with the axial direction of the electrophotographic photosensitive drum.