Process unit including a rotatable shaft along a driving force vector and image forming apparatus including the same

Patent metadata

Field	Value
Publication number	US-9268300-B2
Application number	US-201313770086-A
Country	US
Kind code	B2
Filing date	Feb 19, 2013
Priority date	Feb 22, 2012
Publication date	Feb 23, 2016
Grant date	Feb 23, 2016

Abstract

A process unit includes a photosensitive member that carries an image; a developing device that has a developer carrying member carrying a developer to be supplied to the photosensitive member; a rotating shaft that supports the developing device rotatably for approaching and separating from the photosensitive member; a photosensitive member gear provided to the photosensitive member; and a developing gear provided to the developer carrying member. The photosensitive member gear and the developing gear engage together and driving force can be transmitted, and the rotating shaft is placed on a driving force vector between the gears or on an extended line thereof, the driving force vector being generated from engagement between the photosensitive member gear and the developing gear.

First claim

What is claimed is:

1. A process unit comprising:
a photosensitive member that carries an image;
a developing device that has a developer carrying member carrying a developer to be supplied to the photosensitive member;
a rotating shaft that supports the developing device rotatably for allowing the developer carrying member to approach and separate from the photosensitive member;
a photosensitive member gear provided to the photosensitive member; and
a developing gear provided to the developer carrying member, wherein
the photosensitive member gear and the developing gear engage together and a driving force can be transmitted, and
the rotating shaft is placed on a driving force vector between the gears or on an extended line thereof such that the rotating shaft is located on a same side of the gears as a direction of the driving force vector, the driving force vector being generated from engagement between the photosensitive member gear and the developing gear.

2. The process unit as claimed in claim 1 , wherein
the rotating shaft is placed in such a manner that the driving force vector or the extended line thereof passes on a peripheral surface of the rotating shaft or passes through the inside of the peripheral surface.

3. The process unit as claimed in claim 1 , wherein
a driving force is transmitted from the photosensitive member gear to the developing gear.

4. The process unit as claimed in claim 1 , wherein
a driving force is transmitted from the developing gear to the photosensitive member gear.

5. The process unit as claimed in claim 1 , wherein
Xmin and Xmax respectively denote a minimum value and a maximum value of an inter-axis distance between the photosensitive member and the developer carrying member where a nip formed between the photosensitive member and the developer carrying member can be functionally maintained,
Ymin and Ymax respectively denote a minimum value and a maximum value of the inter-axis distance between the photosensitive member and the developer carrying member where the photosensitive member gear and the developing gear can maintain proper engagement, and
a relationship Ymin<Xmin<Xmax<Ymax holds.

6. The process unit as claimed in claim 1 , wherein
the rotating shaft is provided to the developing device.

7. An image forming apparatus comprising:
the process unit claimed in claim 1 .

8. An image forming apparatus comprising:
at least one of the process unit of claim 1 .

9. The process unit as claimed in claim 1 , wherein
a configuration is made to apply a force to the developing device in a direction such that the developer carrying member approaches the photosensitive member,
L 1 denotes a distance from a center of the rotating shaft to a driving force transmission part at which the driving force is applied between the gears,
L 2 denotes a distance from the center of the rotating shaft to a force applying part at which the force is applied to the developing device, and
a relationship L 1 <L 2 holds.

10. A process unit comprising:
a photosensitive member that carries an image;
an exposure device that approaches toward and separates from the photosensitive member in a moving path;
a developing device that has a developer carrying member carrying a developer to be supplied to the photosensitive member;
a rotating shaft that supports the developing device rotatably for allowing the developer carrying member to approach and separate from the photosensitive member;
a photosensitive member gear provided to the photosensitive member; and
a developing gear provided to the developer carrying member, wherein
the photosensitive member gear and the developing gear engage together and a driving force can be transmitted,
the rotating shaft is placed on a driving force vector between the gears or on an extended line thereof, the driving force vector being generated from engagement between the photosensitive member gear and the developing gear, and
a rotational axis of the rotating shaft is on the moving path of the exposure device.

11. The process unit as claimed in claim 10 , wherein
the rotating shaft is on a side opposite a vector direction of the driving force vector.

12. The process unit as claimed in claim 11 , wherein
the rotating shaft is outside the moving path of the exposure device.

13. An image forming apparatus comprising:
the process unit claimed in claim 11 .

14. A process unit comprising:
a photosensitive member that carries an image;
an exposure device that approaches toward and separates from the photosensitive member;
a developing device that has a developer carrying member carrying a developer to be supplied to the photosensitive member;
a rotating shaft that supports the developing device rotatably for allowing the developer carrying member to approach and to separate from the photosensitive member;
a photosensitive member gear provided to the photosensitive member; and
a developing gear provided to the developer carrying member, wherein
the photosensitive member gear and the developing gear engage together and a driving force can be transmitted,
the rotating shaft is placed on a driving force vector between the gears or on an extended line thereof, the driving force vector being generated from engagement between the photosensitive member gear and the developing gear, and
the exposure device, a rotational axis of the rotating shaft and the photosensitive member gear are in a straight line such that the exposure device is between the rotational axis of the rotating shaft and the photosensitive member gear.

15. The process unit as claimed in claim 14 , wherein
the rotating shaft is on a side opposite a vector direction of the driving force vector.

16. The process unit as claimed in claim 14 , wherein
the rotating shaft is outside a width of the exposure device.

17. An image forming apparatus comprising:
the process unit claimed in claim 14 .

Assignees

• Shimizu Yoshiyuki
• Ooyoshi Hirobumi
• Hamada Manabu
• Ricoh Co Ltd

Inventors

• Shimizu Yoshiyuki
• Ooyoshi Hirobumi
• Hamada Manabu

Classifications

• G03G21/1814 Primary

  Details of parts of process cartridge, e.g. for charging, transfer, cleaning, developing (G03G21/1835 takes precedence) · CPC title

• G03G21/1857

  for transmitting mechanical drive power to the process cartridge, drive mechanisms, gears, couplings, braking mechanisms · CPC title

• G03G21/1821 Primary

  means for connecting the different parts of the process cartridge, e.g. attachment, positioning of parts with each other, pressure/distance regulation (G03G21/1825 takes precedence) · CPC title