Image forming apparatus

• US 5,414,493 A
• Filed: 08/25/1994
• Issued: 05/09/1995
• Est. Priority Date: 01/19/1990
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Umezawa, Masao, Imai, Nobuhiro, Kobayashi, Tatsuya, Ito, Akira, Murata, Daisuke, Tada, Hideki, Kojima, Hisayoshi, Katoh, Motoi, Seto, Kaoru, Fujii, Haruo
• Primary Examiner(s): Gellner, M. L.
• Assistant Examiner(s): STANZIONE, PATRICK
• Application Number:
  US08/295,490
• Time in Patent Office: 257 Days
• Field of Search: 346/157, 355/200, 355/210, 355/211, 355/245, 355/260, 355/326, 355/327
• US Class Current: 399/112
• CPC Class Codes: G03G 21/1623 Means to access the interior of the apparatus
• CPC Class Codes: G03G 21/1628 Clamshell type G03G21/1638 takes precedence
• CPC Class Codes: G03G 21/1807 colour
• CPC Class Codes: G03G 2221/1603 for multicoloured copies
• CPC Class Codes: G03G 2221/1633 Details concerning the developing process
• CPC Class Codes: G03G 2221/169 Structural door designs

Abstract

An image forming apparatus includes a detachably mountable process cartridge, the process cartridge including an image bearing member and a color developing device actable on the image bearing member, the color developing device containing plural developing units having yellow developer, respectively; detachably mountable developing device actable on the image bearing member in the process cartridge, the detachably mountable developing device containing black developer and being detachably mountable independently of the process cartridge; and a device for forming a latent image on the image bearing member; a transfer device for transferring a developed image from the image bearing member to a recording material.

Claims

1. An image forming apparatus having a main assembly, said image forming apparatus comprising:

a process cartridge detachably mountable relative to said main assembly of said image forming apparatus, said process cartridge comprising an image bearing member and at least one developing means;

a developing unit, which is separable from said process cartridge, for supplying a developer to said image bearing member,

said developing unit comprising a developing roller for bearing a developer, wherein when said apparatus is in operation, said developing roller is positioned in an operative position close to or in contact with said image bearing member;

mounting means for detachably mounting said process cartridge to said main assembly; and

a cover openable relative to said main assembly having said mounting means, said cover being disposed to provide direct access to said process cartridge and to permit mounting and demounting of said process cartridge relative to said main assembly, wherein when said cover is opened, said developing roller moves away from the operative position.

2. An apparatus according to claim 1, wherein said at least one developing means contains one of yellow, magenta, and cyan developers.

3. An apparatus according to claim 1, wherein said main assembly is divisible into a first body and a second body, wherein said first body supports said process cartridge and said developing unit.

4. An apparatus according to claim 1, wherein said process cartridge further comprises charging means for uniformly charging said image bearing member and cleaning means for removing residual matter from said image bearing member.

5. An apparatus according to claim 1, wherein said process cartridge comprises at least three developing means respectively containing yellow, magenta, and cyan developers.

6. An apparatus according to claim 1, wherein said cover further provides direct access to said developing unit.

7. An apparatus according to claim 1, wherein said developing unit comprises a container for containing a black developer.

8. An image forming apparatus having a main assembly, said image forming apparatus comprising:

an image bearing member;

a developing unit detachably mountable relative to said main assembly, said developing unit comprising a developing roller for supplying a developer to said image bearing member, wherein when said apparatus is in operation, said developing roller is positioned in an operative position close to or in contact with said image bearing member;

mounting means for detachably mounting said developing unit to said main assembly; and

a cover openable relative to said main assembly having said mounting means, said cover being disposed to provide direct access to said developing unit and to permit mounting and demounting of said developing unit relative to said main assembly, wherein when said cover is opened, said developing roller moves away from the operative position.

9. An apparatus according to claim 8, wherein said main assembly is divisible into a first body and a second body, wherein said first body supports said image bearing member and said developing unit.

10. An apparatus according to claim 8, wherein said developing unit comprises a container for containing a black developer.

11. An apparatus according to claim 8, wherein said main assembly further supports at least one additional developing means.

12. An apparatus according to claim 11, wherein said at least one additional developing means contains one of yellow, magenta, and cyan developers.

13. An apparatus according to claim 8, wherein said main assembly further comprises charging means for uniformly charging said image bearing member and cleaning means for removing residual matter from said image bearing member.