| US 7,580,656 B2 | ||
| Image forming apparatus featuring reduced shock attributable to a speed difference between a driving gear and a driven gear of a developing device | ||
| Akinori Tanaka, Abiko (Japan) | ||
| Assigned to Canon Kabushiki Kaisha, Tokyo (Japan) | ||
| Filed on Sep. 11, 2006, as Appl. No. 11/530,640. | ||
| Claims priority of application No. 2005-264490 (JP), filed on Sep. 12, 2005. | ||
| Prior Publication US 2007/0059043 A1, Mar. 15, 2007 | ||
| Int. Cl. G03G 15/01 (2006.01) | ||
| U.S. Cl. 399—227 | 1 Claim |
| 1. An image forming apparatus comprising:
an image bearing member on which an electrostatic image is formed by an exposure device;
a rotatable member;
a developing device carried on said rotatable member and movable, by rotation of said rotatable member, to a developing position
where said developing device is opposed to said image bearing member;
a driven gear which is provided in said developing device and which receives a driving force for operating said developing
device;
a driving gear, provided in a main assembly of the image forming apparatus, for driving engagement with said driven gear of
said developing device which is located at the developing position, wherein said driving gear, when said developing device
is moving toward the developing position, is driven such that moving direction thereof is the same as a moving direction of
said driven gear at an engagement portion with said driven gear,
wherein upon driving engagement between said driven gear and said driving gear, a peripheral speed VA of said driven gear
which is being moved by said rotatable member on an addendum circle thereof at said engagement portion and a peripheral speed
VB of said driving gear on an addendum circle thereof satisfy:
0.9≤VA/VB≤1.0;
an inertia member, disposed in a driving train between said driving source and said driving gear, for providing said driving
train with a moment of inertia; and
a driving engagement member, provided in said driving train, for ON/OFF control of transmission of the driving force from
said driving source to said driving gear,
wherein said inertia member is disposed in a driving train upstream of a driving shaft portion supporting said driving engagement
member with respect to a drive transmission path, and
wherein said driving engagement member starts drive transmission before contact between the addendum circle of said driving
gear and the addendum circle of said driven gear, and when the addendum circle of said driving gear and the addendum circle
of said driven gear are contacted, said driving gear is rotating at a predetermined rotational frequency.
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