Process cartridge having a particular electrical contact arrangement and image forming apparatus using such a process cartridge

An electrophotographic image forming apparatus for use with an electrophotographic process cartridge, said image forming apparatus comprising:

• a cavity for receiving the cartridge, the cartridge including a casing having a first opening and a second opening, a photosensitive drum, a driven gear, a charging bias contact, a developing bias contact, and a guide member formed by a protuberance from the casing adjacent one end of the photosensitive drum for guiding the cartridge when the cartridge is inserted into said cavity in a general insertion direction that is transverse to an axis of the photosensitive drum to an operative position in said cavity and for supporting the cartridge in the operative position;
• a member for cooperating with the guide member of the cartridge when the cartridge is inserted into said cavity;
• a driving gear for engaging the driven gear of the cartridge when the cartridge is in the operative position to thereby rotate the photosensitive drum;
• a member for supplying light through the first opening of the casing for forming a latent image on the photosensitive drum when the cartridge is in the operative position;
• a member for passing a transfer material past the second opening of the casing when the cartridge is in the operative position for transferring a developed image from the photosensitive drum to the transfer material;
• an earth contact disposed to one side of said cavity for engaging and earthing an earth contact provided by the protuberance of the cartridge when the cartridge is in the operative position;
• an apparatus charging bias contact and an apparatus developing bias contact, each disposed at an opposite side of said cavity that is opposite said one side, for engaging the charging bias contact and the developing bias contact, respectively, of the cartridge when the cartridge is in the operative position, said apparatus charging bias contact and said apparatus developing bias contact being disposed adjacent to and respectively forwardly and rearwardly of an axis of said driving gear relative to the general insertion direction;
• and
• a member for supplying a charging bias voltage and a developing bias voltage to said apparatus charging bias contact and said apparatus developing bias contact, respectively.

An electrophotographic process cartridge that is removably mountable onto a main body of an electrophotographic image forming apparatus, said process cartridge comprising:

• a casing member containing a rotatable photosensitive drum, said casing member having a first opening for passing light to the drum for forming a latent image thereon and a second opening for transferring developed images from the drum to a transfer material, and the drum being mounted in said casing member in a front portion thereof relative to a general insertion direction of said process cartridge into the image forming apparatus;
• a driven helical gear co-axial with the drum and provided at one side of said casing member;
• a charging member operable on the drum for charging the drum;
• a developing member, operable on the drum for developing a latent image formed on the drum;
• a cleaning member operable on the drum for cleaning the drum;
• a protuberance adjacent one end of the drum and protruding outwardly of said casing member at said one side thereof, said protuberance forming a guide member for guiding said process cartridge in the general insertion direction when said process cartridge is inserted into the image forming apparatus;
• a toner detecting member for detecting an amount of toner in a toner container said toner detecting member being connected to a toner detection contact provided at an opposite side of said casing member, which is opposite said one side, and rearwardly of a developing bias contact;
• and
• a spur gear, disposed coaxially with the drum at said opposite side of said casing member, for driving a transfer roller of the image forming apparatus,
• wherein said process cartridge is adapted to be inserted into an operative position in the image forming apparatus in the general insertion direction, which is transverse to an axis of the drum and generally in a direction from the toner supply to said cleaning member,
• wherein an earth contact is provided by said protuberance at said one side of said casing member for earthing the drum with respect to the image forming apparatus when said process cartridge is mounted on the main body, and
• wherein a charging bias contact and the developing bias contact are provided at said opposite side of said casing member for receiving a charging bias and a developing bias, respectively, from the image forming apparatus when said process cartridge is mounted on the main body, the charging bias contact and the developing bias contact being disposed adjacent to and respectively forwardly and rearwardly of the axis of the drum relative to the general insertion direction.

An electrophotographic image forming apparatus for use with an electrophotographic process cartridge, said image forming apparatus comprising:

• a cavity for receiving the process cartridge, the process cartridge including a casing member containing a rotatable photosensitive drum, the casing member having a first opening for passing light to the drum for forming a latent image thereon and a second opening for transferring developed images from the drum to a transfer material, and the drum being mounted in the casing member in a front portion thereof relative to a general insertion direction of the process cartridge into said image forming apparatus;
• a driven helical gear co-axial with the drum and provided at one side of the casing member;
• a charging member operable on the drum for charging the drum;
• a developing member, operable on the drum for developing a latent image formed on the drum;
• a cleaning member operable on the drum for cleaning the drum;
• a protuberance adjacent one end of the drum and protruding outwardly of the casing member at the one side thereof, the protuberance forming a guide member for guiding the process cartridge in the general insertion direction when the process cartridge is inserted into said cavity;
• a toner detecting member for detecting an amount of toner in a toner container, the toner detecting member being connected to a toner detection contact provided at an opposite side of the casing member, which is opposite the one side of the casing member, and rearwardly of a developing bias contact;
• and a spur gear, disposed coaxially with the drum at the opposite side of the casing member, for driving a transfer roller of said image forming apparatus, wherein the process cartridge is adapted to be inserted into an operative position in said image forming apparatus in the general insertion direction, which is transverse to an axis of the drum and generally in a direction from the toner supply to the cleaning member, wherein an earth contact is provided by the protuberance at the one side of the casing member for earthing the drum with respect to said image forming apparatus when the process cartridge is mounted in said cavity, and wherein a charging bias contact and the developing bias contact are provided at the opposite side of the casing member for receiving a charging bias and a developing bias, respectively, from said image forming apparatus when the process cartridge is mounted in said cavity, the charging bias contact and the developing bias contact being disposed adjacent to and respectively forwardly and rearwardly of the axis of the drum relative to the general insertion direction;
• a member for cooperating with the guide member of the process cartridge when the process cartridge is inserted into said cavity;
• a driving gear for engaging the driven helical gear of the process cartridge when the process cartridge is in the operative position to thereby rotate the drum;
• a member for supplying light through the first opening of the casing member for forming a latent image on the drum when the process cartridge is in the operative position;
• a member for passing a transfer material past the second opening of the casing member when the process cartridge is in the operative position for transferring a developed image from the drum to the transfer material;
• an earth contact disposed to one side of said cavity for engaging and earthing the earth contact of the process cartridge when the process cartridge is in the operative position;
• an apparatus charging bias contact and an apparatus developing bias contact, each disposed at an opposite side of said cavity that is opposite said one side of said cavity, for engaging the charging bias contact and the developing bias contact, respectively, of the process cartridge when the process cartridge is in the operative position, said apparatus charging bias contact and said apparatus developing bias contact being disposed adjacent to and respectively forwardly and rearwardly of an axis of said driving gear relative to the general insertion direction;
• and
• a member for supplying a charging bias voltage and a developing bias voltage to said apparatus charging bias contact and said apparatus developing bias contact, respectively.