Pressurizing unit to apply force to developing unit of development cartridge

Patent metadata

Field	Value
Publication number	US-2018307179-A1
Application number	US-201816017635-A
Country	US
Kind code	A1
Filing date	Jun 25, 2018
Priority date	Dec 28, 2015
Publication date	Oct 25, 2018
Grant date	—

Abstract

A development cartridge detachable from a main body of an image forming apparatus includes a photosensitive unit including a photosensitive drum and a developing unit including a developing roller. The developing unit is coupled to the photosensitive unit such that the developing unit is movable to a development position where a development nip forms by contact between the developing roller and the photosensitive drum and movable to a release position where the development nip is released. The development cartridge further includes a pressurizing unit movable to a first position where the pressurizing unit applies an elastic force to the developing unit in a direction such that the developing unit is maintained in the development position, and movable to a second position where the pressurizing unit applies an elastic force to the developing unit in a direction such that the developing unit is maintained in the release position.

First claim

1 . A development cartridge for an image forming apparatus, the development cartridge comprising:
a photosensitive unit including a photosensitive drum; a developing unit including a developing roller, the developing unit being movable to a development position where a development nip is formed by contact between the developing roller and the photosensitive drum and movable to a release position where the development nip is released; and a pressurizing unit movable to a first position where the pressurizing unit applies a first elastic force to the developing unit in a first direction to maintain the developing unit in the development position, and movable to a second position where the pressurizing unit applies a second elastic force to the developing unit in a second direction to maintain the developing unit in the release position.

2 . The development cartridge of claim 1 , wherein
the developing unit is rotatable to the development position and the release position with respect to a hinge shaft provided in the photosensitive unit, and the pressurizing unit is mounted on a rotation shaft provided in the photosensitive unit to rotate to the first and second positions.

3 . The development cartridge of claim 2 , wherein
the pressurizing unit includes:
a rotation member rotatable about the rotation shaft,
a pressing member, slidable on the rotation member, to push the developing unit, and
an elastic member to apply an elastic force to the pressing member so that the pressing member presses the developing unit, and
the developing unit further includes:
a first pressing portion contacted by the pressing member when the pressurizing unit is at the first position, and
a second pressing portion contacted by the pressing member when the pressurizing unit is at the second position.

4 . The development cartridge of claim 3 , wherein
based on a virtual line connecting the hinge shaft and the rotation shaft to each other, the first pressing portion is on one side of the virtual line and the developing roller is on another side of the virtual line, and the second pressing portion is on the another side of the virtual line.

5 . The development cartridge of claim 3 , wherein the developing unit further includes:
a first stopper to prevent the pressurizing unit from rotating beyond the first position, and a second stopper to prevent the pressurizing unit from rotating beyond the second position.

6 . The development cartridge of claim 5 , wherein the developing unit further includes:
a first position determiner to maintain the pressurizing unit in the first position, the first position determiner being on a first side of the pressurizing unit and the first stopper being on a second side of the pressurizing unit when the pressurizing unit is at the first position, and a second position determiner to maintain the pressurizing unit in the second position, the second position determiner being on the second side of the pressurizing unit and the second stopper being on the first side of the pressurizing unit when the pressurizing unit is at the second position.

7 . The development cartridge of claim 1 , wherein
the developing unit is coupled to the photosensitive unit and slidable to the development position and the release position, one end portion of the pressurizing unit is rotatable about a first rotation shaft provided in the photosensitive unit, and another end portion of the pressurizing unit is rotatable about a second rotation shaft provided in the developing unit.

8 . The development cartridge of claim 7 , wherein the pressurizing unit includes:
a first rotation member rotatable about the first rotation shaft, a second rotation member rotatable about the second rotation shaft and slidably connected to the first rotation member, and an elastic member to apply an elastic force to the second rotation member so that the second rotating member presses the developing unit, wherein, based on a virtual line passing through the first rotation shaft and perpendicular to a sliding direction of the developing unit, when the pressurizing unit is at the first position, the second rotation shaft is at a same side of the virtual line as the developing roller, and when the pressurizing unit is at the second position, the second rotation shaft is at one side of the virtual line and the developing roller is on another side of the virtual line.

9 . The development cartridge of claim 7 , wherein
one of the photosensitive unit and the developing unit includes a guide slot extending in a sliding direction of the developing unit, the other of the photosensitive unit and the developing unit includes a guide protrusion inserted into the guide slot, and a width of the guide slot in a direction perpendicular to the sliding direction is greater than a width of the guide protrusion.

10 . The development cartridge of claim 1 , wherein
the photosensitive unit further includes a mounting portion where the development cartridge is mounted, and the pressurizing unit is mounted on the photosensitive unit and rotatable to the first and second positions.

11 . The development cartridge of claim 10 , wherein
the developing unit further includes a pressing portion, and the pressurizing unit includes:
a rotation member rotatable with respect to the photosensitive unit;
a pressing member slidable on the rotation member and including a receiving portion to receive the pressing portion, and
an elastic member to apply an elastic force to the pressing member so that the pressing member presses the pressing portion.

12 . The development cartridge of claim 11 , further comprising a maintaining unit, provided in the photosensitive unit, to maintain the pressurizing unit in the second position.

13 . The development cartridge of claim 12 , wherein the maintaining unit includes:
a return spring to elastically bias the pressurizing unit in a direction of rotation to the second position, and a stopper to prevent the pressurizing unit from rotating beyond the second position.

14 . The development cartridge of claim 12 , wherein the maintaining unit includes:
an elastic arm including a first combining portion, and a second combining portion, in the pressurizing unit, having a shape complementary to that of the first combining portion so that the second combining portion is coupled to the first combining portion when the pressurizing unit is at the second position.

15 . An image forming apparatus, comprising:
a main body; and a development cartridge detachable from the main body, the development cartridge including:
a photosensitive unit including a photosensitive drum,
a developing unit including a developing roller, the developing unit being movable to a development position where a development nip is formed by contact between the developing roller and the photosensitive drum and movable to a release position where the development nip is released, and
a pressurizing unit movable to a first position where the pressurizing unit applies a first elastic force to the developing unit in a first direction to maintain the developing unit in the development position, and movable to a second position where the pressurizing unit applies a second elastic force to the developing unit in a second direction to maintain the developing unit in the release position.

Assignees

• Hp Printing Korea Co Ltd

Inventors

• Lee Sang-Hoon
• Kim Joon-Hee

Classifications

• G03G21/1853

  the process cartridge being mounted perpendicular to the axis of the photosensitive member · CPC title

• G03G21/1821

  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

• G03G15/06

  for developing · CPC title

• G03G15/0865

  Arrangements for supplying new developer · CPC title

• G03G2215/066

  Toner cartridge or other attachable and detachable container for supplying developer material to replace the used material · CPC title