Image forming apparatus

• US 20020025191A1
• Filed: 08/01/2001
• Published: 02/28/2002
• Est. Priority Date: 08/02/2000
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Kitayama, Kunihiko
• Granted Patent: US 6,574,446 B2
• Time in Patent Office: Days
• US Class Current: 399/222
• CPC Class Codes: F16D 3/44 the intermediate member being connected to the coupling parts by ridges, pins, balls, or the like guided in grooves or between cogs
• CPC Class Codes: G03G 15/757 Drive mechanisms for photosensitive medium, e.g. gears
• CPC Class Codes: G03G 21/186 Axial couplings
• CPC Class Codes: G03G 2221/1657 transmitting mechanical drive power

Abstract

An image forming apparatus includes a process unit detachably mountable to a main assembly of the apparatus, the process unit including an image bearing member for bearing an electrostatic image and process means actable on the image bearing member, the process means having a rotational shaft; a driving shaft, substantially co-axial with the rotational shaft, for rotating the rotational shaft; and a drive transmitting member, engaged with the driving shaft and with the rotational shaft, for transmitting a driving force to the rotational shaft from the driving shaft; wherein the drive transmitting member is engaged with the driving shaft with a play and is engaged with the rotational shaft with a play.

Claims

1. An image forming apparatus comprising:

a process unit detachably mountable to a main assembly of said apparatus, said process unit including an image bearing member for bearing an electrostatic image and process means actable on said image bearing member, said process means having a rotational shaft;

a driving shaft, substantially co-axial with said rotational shaft, for rotating said rotational shaft; and

a drive transmitting member, engaged with said driving shaft and with said rotational shaft, for transmitting a driving force to said rotational shaft from said driving shaft;

wherein said drive transmitting member is engaged with said driving shaft with a play and is engaged with said rotational shaft with a play.

2. An apparatus according to claim 1, further comprising an image bearing member rotating shaft, and said image bearing member is provided with an engaging portion engaged with said image bearing member rotating shaft substantially without a play.

3. An apparatus according to claim 1, wherein said process cartridge includes a plurality of said process means each having said rotational shaft, and includes said drive transmitting member for each of said process means.

4. An apparatus according to claim 3, wherein said process means are charging means for electrically charging said image bearing member and developing means for developing an electrostatic image on said image bearing member.

5. An apparatus according to claim 1, wherein said process means includes a rotatable member which is rotated at a peripheral speed which is different from that of image bearing member.

6. An apparatus according to claim 1, wherein said drive transmitting member is pivotable about a point on an axis of said driving shaft and a point on an axis of said rotational shaft.

7. An apparatus according to claim 6, wherein an angle in which said drive transmitting member is pivotable relative to each of said driving shaft and said rotational shaft is larger than a smaller one of an angle between said drive transmitting member and said driving shaft and an angle between said drive transmitting member and said rotational shaft.

8. An apparatus according to claim 1, wherein the play is not less than 200 μ

m at portions where said drive transmitting member and said driving shaft are engaged with each other, and where said drive transmitting member and said rotational shaft are engaged with each other.

9. An apparatus according to claim 1, wherein said drive transmitting member is provided with grooves for engagement with said driving shaft and said rotational shaft, respectively, and said driving shaft and said rotational shaft are provided with projections for engagement with said grooves, respectively.

10. An apparatus according to claim 9, wherein said groove of said drive transmitting member engageable with said driving shaft and said groove of said drive transmitting member are extended in different directions.

11. An apparatus according to claim 10, wherein said directions are orthogonal to each other.

12. An apparatus according to claim 9, wherein said drive transmitting member is provided with a guide portion for guiding engagement of the projection into the groove.

13. An apparatus according to claim 9, wherein Said drive transmitting member is provided with a step for preventing abutment of said driving shaft or said rotational shaft to said drive transmitting member.

14. An apparatus according to claim 1, wherein Said drive transmitting member is coupled with one of said driving shaft and said rotational shaft.

15. An apparatus according to claim 14, wherein Said drive transmitting member is demountable from said driving shaft or said rotational shaft to which said drive transmitting member is mounted.

16. An apparatus according to claim 1, wherein Said drive transmitting member comprises two members which are movable toward and away from each other, and said two members are coupled with said driving shaft and said rotational shaft, respectively.

17. An apparatus according to claim 16, wherein Said two members have the same shape.

18. An apparatus according to claim 16, wherein said drive transmitting member is provided with a projection or a recess which is brought into engagement with the driving shaft by rotation of said rotational shaft relative to said driving shapt.

19. An apparatus according to claim 18, wherein said projection or recess is disposed approx. 45°

away from said groove and said projection as seen from an axis of said driving shaft or said rotational shaft.

21. An apparatus according to claim 1, wherein said image bearing member has a rotational shaft which is engaged with a driving shaft provided in the main assembly of the apparatus with a play which is smaller than the play with which said drive transmitting member is engaged with said driving shaft or with said rotational shaft.

23. An apparatus according to claim 21, wherein said image bearing member has a rotational shaft which is engaged with a driving shaft provided in the main assembly of the apparatus subly without a play.

20. A process cartridge detachably mountable to an image forming apparatus, said process cartridge comprising:

an image bearing member for bearing an electrostatic image;

process means actable on said image bearing member, said process means including a rotational shaft; and

a drive transmitting member for receiving a driving force from a driving shaft provided in a main assembly of the apparatus;

wherein said drive transmitting member is engageable with said driving shaft with a play and is engaged with said rotational shaft with a play.

22. A process cartridge according to claim 20, wherein said image bearing member has a rotational shaft which is engageable with a driving shaft provided in the main assembly of the apparatus with a play which is smaller than the play with which said drive transmitting member is engaged with said driving shaft or with said rotational shaft.

24. A process cartridge according to claim 22, wherein said image bearing member has a rotational shaft which is engageable with a driving shaft provided in the main assembly of the apparatus substantially without a play.