US 9,851,670 B2 · Image forming apparatus to suppress excessive interposing toner

Abstract

When ending image forming, a state is realized where charging by a charging roller is stopped (charging bias off) and also applying DC voltage at a developing device is stopped (developing bias DC off). In this state, AC voltage is applied to the developing device (developing bias AC on), thereby adhering toner to the surface of a photosensitive drum and forming interposing toner. Driving of the photosensitive drum and an intermediate transfer belt is then stopped in the state with the interposing toner interposed between the photosensitive drum and intermediate transfer belt.

Drawings

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Drawings

Claims17

Dependent claims

An image forming apparatus comprising:

an image bearing member configured to bear an image thereon;
a charging device configured to charge a surface of the image bearing member;
an exposing device configured to expose the charged surface of the image bearing member and form an electrostatic latent image;
a developing device configured to develop the electrostatic latent image formed on the surface of the image bearing member by voltage being applied where AC voltage has been superimposed on DC voltage;
a rotating member, provided rotatably, and disposed in contact with the image bearing member;
and
a control unit configured to effect control to, corresponding to an end of an image forming job,
stop application of the DC voltage by the charging device in a state where the image bearing member is driven,
stop application of the DC voltage of the developing device after the surface of the image bearing member facing the charging device when the application of DC voltage by the charging device stops has passed the developing device, and
stop driving of the image bearing member after application of DC voltage by the developing device has stopped,
wherein the control unit is configured to execute a mode of controlling driving of the image bearing member, corresponding to an end of the image forming job, after stopping application of the DC voltage at the charging device and the developing device, the control unit drives the image bearing member in a state with AC voltage applied to the developing device so as to adhere toner to the image bearing member, and controls driving of the image bearing member so that the surface of the image bearing member, that has passed a position facing the developing device at a time of AC voltage being applied to the developing device, stops at a position in contact with the rotating member.

8 more elements

An image forming apparatus comprising:

an image bearing member configured to bear an image thereon;
a charging device configured to charge a surface of the image bearing member;
an exposing device configured to expose the charged surface of the image bearing member and form an electrostatic latent image;
a developing device configured to develop the electrostatic latent image formed on the surface of the image bearing member by voltage being applied where AC voltage has been superimposed on DC voltage;
an intermediate transfer member disposed in contact with the image bearing member, the intermediate transfer member provided rotatably and configured to bear a toner image transferred from the image bearing member;
a transfer member configured to transfer the toner image transferred onto the intermediate member onto a recording medium at a transfer portion;
a bias applying device configured to apply bias to the transfer member;
and
a control unit configured to, at a predetermined timing, execute a first stopping mode of forming interposing toner on a surface of the image bearing member and stopping driving of the image bearing member and the intermediate transfer member in a state where the interposing toner is interposed between the image bearing member and the intermediate transfer member, and a second stopping mode of stopping driving of the image bearing member and the intermediate transfer member in a state where no interposing toner is interposed between the image bearing member and the intermediate transfer member, and configured to execute a correction mode to correct bias applied to the transfer member at a time of image forming, by applying a test bias by the bias applying device before an image forming operation, and in a case of executing the correction mode after having stopped in the first stopping mode, sets the test bias applied during the interposing toner passing the transfer portion higher than the test bias applied in a case of executing the correction mode after having stopped in the second stopping mode.

6 more elements

An image forming apparatus comprising:

an image bearing member configured to bear an image thereon;
a charging device configured to charge a surface of the image bearing member;
an exposing device configured to expose the charged surface of the image bearing member and form an electrostatic latent image;
a developing device configured to develop the electrostatic latent image formed on the surface of the image bearing member by voltage being applied where AC voltage has been superimposed on DC voltage;
a rotating member, provided rotatably, and disposed in contact with the image bearing member;
and
a control unit configured to effect control to, corresponding to an end of an image forming job,
stop application of the DC voltage by the charging device in a state where the image bearing member is driven,
stop application of the DC voltage of the developing device after the surface of the image bearing member facing the charging device when the application of DC voltage by the charging device stops has passed the developing device, and
stop driving of the image bearing member after application of DC voltage by the developing device has stopped,
wherein the control unit is configured to execute a mode of controlling driving of the image bearing member, corresponding to an end of the image forming job, after stopping application of the DC voltage at the developing device, the control unit drives the image bearing member in a state with AC voltage applied to the developing device so as to adhere toner to the image bearing member, and controls driving of the image bearing member so that the surface of the image bearing member, that has passed a position facing the developing device at a time of AC voltage being applied to the developing device, stops at a position in contact with the rotating member.

8 more elements

Dependencies are inferred from the claim text.

Description40,730 words

Summary605 words

#Field of the Invention

#The present disclosure generally relates to an electrophotographic or electrostatic image forming apparatus, such as a multifunction apparatus having multiple functions of a copier, printer, and facsimile.

#Description of the Related Art

Brief description of the drawings76 figures

#FIG. 1 is a schematic configuration diagram according to an image forming apparatus according to a first embodiment.

#FIG. 2 is a diagram regarding surface potential of the photosensitive drum when forming images in the first embodiment.

#FIG. 3 is a schematic diagram illustrating a cross-section of the intermediate transfer belt according to the first embodiment.

Detailed description38,466 words

#Hereinafter, image forming according to embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Note that configurations described in the embodiments are merely examples, and the scope of the present disclosure is not limited to the configurations.

#A first embodiment will be described with reference to FIGS. 1 through 7. First, a schematic configuration of the image forming apparatus according to the present embodiment will be described with reference to FIG. 1.

#Image Forming Apparatus

Facts

Application

15/244,928Filed 23 Aug 2016

Priority

JP 2015-16842028 Aug 2015

Published

US 2017/0060061 A12 Mar 2017

Granted

26 Dec 2017

Term ends

23 Aug 2036

Estimated · how

20 years from earliest known nonprovisional domestic filing plus recorded patent term adjustment. Maintenance-fee lapses, terminal disclaimers and statutory extensions have not been checked. The continuity chain may be incomplete; this is not an enforceability determination.

Classification4 codes

G03G 15/50
Apparatus for electrographic processes using a charge pattern: machine control of apparatus for electrographic processes using a charge pattern,…
G03G 15/0266
For laying down a uniform charge, e.g. for sensitising; Corona discharge devices: arrangements for controlling the amount of charge
G03G 15/065
For developing: arrangements for controlling the potential of the developing electrode
G03G
Electrography

Timeline

28 Aug 2015Priority claimedJP 2015-168420
23 Aug 2016Application filedUS 15/244,928
14 Nov 2016Assigned to Canon Kabushiki Kaishaassignment of assignor's interest
2 Mar 2017PublishedUS 2017/0060061 A1
26 Dec 2017GrantedUS 9,851,670 B2
12 Oct 2026TodayWithin its term
23 Aug 2036Term endsEstimated

Image forming apparatus to suppress excessive interposing toner

Life of this patent

Image forming apparatus to suppress excessive interposing toner

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims17

Description40,730 words

Drawings

Classification4 codes

Life of this patent

Description40,730 words