Image forming apparatus having capacitance detection

An image forming apparatus configured to form an image on a recording medium, the image forming apparatus comprising:

• an image bearing member on which a latent image is to be formed;
• a developer carrying member configured to carry a developer;
• a conductive member having a conductive property, the conductive member being paired with one of the developer carrying member and the image bearing member to form a capacitor;
• a contact-separation member configured to assume a first position for bringing the developer carrying member into contact with the image bearing member and a second position for separating the developer carrying member from the image bearing member;
• a detecting unit configured to detect a value relating to a capacitance of the capacitor when a voltage is applied to the capacitor;
• and
• a control unit configured to detect whether or not the image forming apparatus is ready for image formation based on a first detected result and a second detected result, the first detected result being detected by the detecting unit when the contact-separation member assumes the first position, the second detected result being detected by the detecting unit when the contact-separation member assumes the second position,
• wherein the developer carrying member is provided in a developing cartridge which is removably mountable to an apparatus main body of the image forming apparatus,
• the image bearing member is provided in an image bearing member cartridge which is removably mountable to the apparatus main body separately from the developing cartridge,
• the capacitor is provided in a corresponding one of the developing cartridge and the image bearing member cartridge, and
• the control unit is configured to discriminate the following three states:
• (1) a first state in which the corresponding one of the developing cartridge and the image bearing member cartridge which is provided with the capacitor is not mounted to the apparatus main body;
• (2) a second state in which the corresponding one of the developing cartridge and the image bearing member cartridge which is provided with the capacitor is mounted to the apparatus main body, but other of the developing cartridge and the image bearing member cartridge which is not provided with the capacitor is not mounted to the apparatus main body;
• and
• (3) a third state in which the developing cartridge and the image bearing member cartridge are both mounted to the apparatus main body.

An image forming apparatus configured to form an image on a recording medium, the image forming apparatus comprising:

• an image bearing member on which a latent image is to be formed;
• a developer carrying member configured to carry a developer;
• a conductive member having a conductive property, the conductive member being paired with one of the developer carrying member and the image bearing member to form a capacitor;
• a contact-separation member configured to assume a first position for bringing the developer carrying member into contact with the image bearing member and a second position for separating the developer carrying member from the image bearing member;
• a detecting unit configured to detect a value relating to a capacitance of the capacitor when a voltage is applied to the capacitor;
• and
• a control unit configured to detect whether or not the image forming apparatus is ready for image formation based on a first detected result and a second detected result, the first detected result being detected by the detecting unit when the contact-separation member assumes the first position, the second detected result being detected by the detecting unit when the contact-separation member assumes the second position,
• wherein the developer carrying member, the image bearing member, and the capacitor are provided in one process cartridge which is removably mountable to an apparatus main body of the image forming apparatus, and
• the control unit is configured to discriminate the following three states based on the first detected result and the second detected result:
• (1) a first state in which the process cartridge is not mounted to the apparatus main body;
• (2) a second state in which the process cartridge is mounted to the apparatus main body, and the developer carrying member and the image bearing member are not switchable between a contact state and a separate state;
• and
• (3) a third state in which the process cartridge is mounted to the apparatus main body, and the developer carrying member and the image bearing member are switchable between the contact state and the separate state.

An image forming apparatus configured to form an image on a recording medium, the image forming apparatus comprising:

• an image bearing member on which a latent image is to be formed;
• a developer carrying member configured to carry a developer;
• a conductive member having a conductive property, the conductive member being paired with one of the developer carrying member and the image bearing member to form a capacitor;
• a contact-separation member configured to assume a first position for bringing the developer carrying member into contact with the image bearing member and a second position for separating the developer carrying member from the image bearing member;
• a detecting unit configured to detect a value relating to a capacitance of the capacitor when a voltage is applied to the capacitor;
• and
• a control unit configured to detect whether or not the image forming apparatus is ready for image formation based on a first detected result and a second detected result, the first detected result being detected by the detecting unit when the contact-separation member assumes the first position, the second detected result being detected by the detecting unit when the contact-separation member assumes the second position,
• wherein the developer carrying member, the image bearing member, and the capacitor are provided in one process cartridge, which is removably mountable to an apparatus main body of the image forming apparatus,
• the process cartridge comprises a contact preventing member, the contact preventing member being removably mountable to the process cartridge and being configured to maintain a state in which the developer carrying member and the image bearing member are separated from each other, and
• the control unit detects whether or not the contact preventing member is mounted to the process cartridge based on the first detected result and the second detected result.

An image forming apparatus configured to form an image on a recording medium, the image forming apparatus comprising:

• an image bearing member on which a latent image is to be formed;
• a developer carrying member configured to carry a developer;
• a conductive member having a conductive property, the conductive member being paired with one of the developer carrying member and the image bearing member to form a capacitor;
• a contact-separation member configured to assume a first position for bringing the developer carrying member into contact with the image bearing member and a second position for separating the developer carrying member from the image bearing member;
• a detecting unit configured to detect a value relating to a capacitance of the capacitor when a voltage is applied to the capacitor;
• and
• a control unit configured to detect whether or not the image forming apparatus is ready for image formation based on a first detected result and a second detected result, the first detected result being detected by the detecting unit when the contact-separation member assumes the first position, the second detected result being detected by the detecting unit when the contact-separation member assumes the second position,
• wherein the capacitor is provided in a cartridge which is removably mountable to an apparatus main body of the image forming apparatus, and
• the control unit detects whether or not the cartridge provided with the capacitor is mounted to the apparatus main body based on only one of the first detected result and the second detected result.

An image forming apparatus configured to form an image on a recording medium, the image forming apparatus comprising:

• an image bearing member on which a latent image is to be formed;
• a developer carrying member configured to carry a developer;
• a conductive member having a conductive property, the conductive member being paired with one of the developer carrying member and the image bearing member to form a capacitor;
• a contact-separation member configured to assume a first position for bringing the developer carrying member into contact with the image bearing member and a second position for separating the developer carrying member from the image bearing member;
• a detecting unit configured to detect a value relating to a capacitance of the capacitor when a voltage is applied to the capacitor;
• and
• a control unit configured to detect whether or not the image forming apparatus is ready for image formation based on a first detected result and a second detected result, the first detected result being detected by the detecting unit when the contact-separation member assumes the first position, the second detected result being detected by the detecting unit when the contact-separation member assumes the second position,
• wherein the conductive member comprises a charging member which charges the image bearing member, and is paired with the image bearing member to form the capacitor.