Image forming apparatus

Patent metadata

Field	Value
Publication number	US-12105463-B2
Application number	US-202318296378-A
Country	US
Kind code	B2
Filing date	Apr 6, 2023
Priority date	Dec 9, 2022
Publication date	Oct 1, 2024
Grant date	Oct 1, 2024

Abstract

An image forming apparatus includes a transfer body that rotates and transfers a transferred image to a target transfer body at a transfer position, plural image holding members that rotate together with the transfer body at different positions along a rotation direction of the transfer body while outer peripheral surfaces of the image holding members come into contact with the transfer body, the image holding members on which a charge erasing operation is sequentially performed after images held on the outer peripheral surfaces sequentially transferred to the transfer body, and in which the charge erasing operation on all the image holding members has been ended, and then rotations of all the image holding members are stopped, a first charge erasing unit that erases charges of an outer peripheral surface of at least one image holding member other than a most downstream image holding member disposed on a most downstream side of the rotation direction with respect to the transfer position, among the plural image holding members, and a second charge erasing unit that erases charges of an outer peripheral surface of the most downstream image holding member and has a charge erasing time shorter than a charge erasing time of the first charge erasing unit.

First claim

What is claimed is:

1. An image forming apparatus comprising:
a toner image transferer that rotates and transfers a transferred image to a target toner image transferer at a transfer position;
a plurality of photosensitive drums that rotate together with the toner image transferer at different positions along a rotation direction of the toner image transferer while outer peripheral surfaces of the photosensitive drums come into contact with the toner image transferer;
a first charge erasing unit that erases charges of an outer peripheral surface of at least one photosensitive drum other than a most downstream photosensitive drum disposed on a most downstream side of the rotation direction with respect to the transfer position, among the plurality of photosensitive drums; and
a second charge erasing unit that erases charges of an outer peripheral surface of the most downstream photosensitive drum and has a charge erasing time shorter than a charge erasing time of the first charge erasing unit,
wherein a charge erasing operation is sequentially performed by the first charge erasing unit and the second charge erasing unit on all the photosensitive drums after completion of transfer of images from the outer peripheral surfaces to the toner image transferer, and
rotations of all the photosensitive drums are stopped after the charge erasing operation on all the photosensitive drums has been ended.

2. The image forming apparatus according to claim 1 ,
wherein the first charge erasing unit includes at least one of an exposing light that exposes the outer peripheral surface of one of the plurality of photosensitive drums or a transfer roll that transfers an image held on the outer peripheral surface of one of the plurality of photosensitive drums to the toner image transferer, and
the second charge erasing unit is a charge erasing unit that is disposed on a downstream side of a position where the most downstream photosensitive drum transfer an image to the toner image transferer and on an upstream side of a charging unit that charges the outer peripheral surface of the most downstream photosensitive drum, in a rotation direction of the most downstream photosensitive drum.

3. The image forming apparatus according to claim 2 ,
wherein the first charge erasing unit includes both the exposing light and the transfer roll.

4. The image forming apparatus according to claim 1 ,
wherein the first charge erasing unit erases charges of an outer peripheral surface of an immediately upstream photosensitive drum disposed on an immediately upstream side of the most downstream photosensitive drum among the plurality of photosensitive drum, and
the second charge erasing unit ends the charge erasing operation by the time when the first charge erasing unit ends the charge erasing operation.

5. An image forming apparatus comprising:
a transfer body that rotates and transfers a transferred image to a target transfer body at a transfer position;
a plurality of image holding members that rotate together with the transfer body at different positions along a rotation direction of the transfer body while outer peripheral surfaces of the image holding members come into contact with the transfer body;
first charge erasing means for erasing charges of an outer peripheral surface of at least one image holding member other than a most downstream image holding member disposed on a most downstream side of the rotation direction with respect to the transfer position, among the plurality of image holding members; and
second charge erasing means for erasing charges of an outer peripheral surface of the most downstream image holding member, the second charge erasing means having a charge erasing time shorter than a charge erasing time of the first charge erasing means,
wherein a charge erasing operation is sequentially performed by the first charge erasing means and the second charge erasing means on all the image holding members after completion of transfer of images from the outer peripheral surfaces to the transfer body, and
rotations of all the image holding members are stopped after the charge erasing operation on all the image holding members has been ended.

Assignees

• Fujifilm Business Innovation Corp

Inventors

• Nakazawa Shota
• Ando Hiroki
• Hamada Hirofumi
• Iida Hirofumi

Classifications

• G03G21/08

  using optical radiation · CPC title

• G03G15/50

  Machine control of apparatus for electrographic processes using a charge pattern, e.g. regulating differents parts of the machine, multimode copiers, microprocessor control (sequencing control G03G21/14) · CPC title

• G03G15/16

  of a toner pattern, e.g. a powder pattern {, e.g. magnetic transfer} · CPC title

• G03G21/06 Primary

  Eliminating residual charges from a reusable imaging member · CPC title

• G03G15/02 Primary

  for laying down a uniform charge, e.g. for sensitising; Corona discharge devices (G03G15/14 takes precedence) · CPC title