Image forming apparatus

Patent metadata

Field	Value
Publication number	US-9285754-B2
Application number	US-201514794171-A
Country	US
Kind code	B2
Filing date	Jul 8, 2015
Priority date	Jul 30, 2014
Publication date	Mar 15, 2016
Grant date	Mar 15, 2016

Abstract

An image forming apparatus includes: an image bearer on which a latent image is formed and developed into a toner image; a transfer member that is arranged so as to come in contact with or face the image bearer to form a transfer position; a cleaning unit that removes and collects untransferred toner; a guide member that guides conveyance of the recording medium; a neutralizing light source that irradiates a position downstream of the transfer position and upstream of the cleaning unit in a running direction of the image bearer with neutralizing light which is incident on and reflected by the recording medium sent out from the transfer position and/or the guide member; and a shielding member that blocks light such that the image bearer is not irradiated directly with a part or whole of neutralizing light emitted from the neutralizing light source.

First claim

What is claimed is:

1. An image forming apparatus comprising:
an image bearer, which runs in a predetermined direction and on which a latent image is formed and developed and a toner image is borne;
a transfer member that is arranged so as to come in contact with or face the image bearer to form a transfer position, and transfers the toner image borne on the image bearer to a recording medium conveyed to the transfer position;
a cleaning unit that removes and collects, from the image bearer, untransferred toner that is attached to a surface of the image bearer without being transferred to the recording medium at the transfer position;
a guide member that is arranged so as to face a non-transfer surface of the recording medium sent out from the transfer position and that guides conveyance of the recording medium;
a neutralizing light source that irradiates a position downstream of the transfer position in a running direction of the image bearer and upstream of the cleaning unit in the running direction of the image bearer with neutralizing light which is incident on and reflected by the recording medium sent out from the transfer position and/or the guide member, to thereby neutralize a surface potential on the image bearer; and
a shielding member that is arranged between the image bearer and the neutralizing light source, and that blocks light such that the image bearer is not irradiated directly with a part or whole of neutralizing light emitted from the neutralizing light source.

2. The image forming apparatus according to claim 1 , wherein the transfer member is a transfer roller that comes in contact with the image bearer and forms a transfer nip as the transfer position.

3. The image forming apparatus according to claim 1 , wherein the guide member is formed such that the guide member is made of a material with a high optical reflectivity in a range in a width direction corresponding to a sheet passing region of a recording medium of a maximum feedable size, and the guide member is made of a material with a low optical reflectivity in a range outside the range corresponding to the sheet passing region in the width direction.

4. The image forming apparatus according to claim 1 , wherein the neutralizing light source is arranged such that neutralizing light that travels on an optical axis of the neutralizing light source is blocked by the shielding member.

5. The image forming apparatus according to claim 1 , wherein the neutralizing light source is arranged such that an emitting surface from which the neutralizing light is emitted faces downward in a direction of gravity.

6. The image forming apparatus according to claim 1 , wherein the cleaning unit includes a cleaning blade that comes in contact with the image bearer.

7. The image forming apparatus according to claim 1 , further comprising:
a developing unit that stores therein toner and develops the latent image formed on the image bearer into the toner image; and
a recycle toner path that supplies, as recycle toner, the untrasferred toner collected by the cleaning unit to the developing unit.

8. The image forming apparatus according to claim 1 , wherein the neutralizing light source is controlled so as to be always in an ON state while an image formation process is performed on the surface of the image bearer.

9. An image forming apparatus comprising:
an image bearer, which runs in a predetermined direction and on which a latent image is formed and developed and a toner image is borne;
an intermediate transfer medium, which is arranged so as to come in contact with the image bearer to form a primary transfer nip and on which the toner image borne on the image bearer is transferred at the primary transfer nip;
a cleaning unit that removes and collects, from the image bearer, untransferred toner that is attached to a surface of the image bearer without being transferred to the recording medium at the primary transfer nip;
a neutralizing light source that irradiates a position downstream of the primary transfer nip in a running direction of the image bearer and upstream of the cleaning unit in the running direction of the image bearer with neutralizing light which is incident on and reflected by a surface of the intermediate transfer medium that has passed through the primary transfer nip, to thereby neutralize a surface potential on the image bearer; and
a shielding member that is arranged between the image bearer and the neutralizing light source, and that blocks light such that the image bearer is not irradiated directly with a part or whole of neutralizing light emitted from the neutralizing light source.

10. The image forming apparatus according claim 9 , wherein the neutralizing light source is arranged such that neutralizing light that travels on an optical axis of the neutralizing light source is blocked by the shielding member.

11. The image forming apparatus according to claim 9 , wherein the neutralizing light source is arranged such that an emitting surface from which the neutralizing light is emitted faces downward in a direction of gravity.

12. The image forming apparatus according to claim 9 , wherein the cleaning unit includes a cleaning blade that comes in contact with the image bearer.

13. The image forming apparatus according to claim 9 , further comprising:
a developing unit that stores therein toner and develops the latent image formed on the image bearer into the toner image; and
a recycle toner path that supplies, as recycle toner, the untransferred toner collected by the cleaning unit to the developing unit.

14. The image forming apparatus according to claim 9 , wherein the neutralizing light source is controlled so as to be always in an ON state while an image formation process is performed on the surface of the image bearer.

Assignees

• Nodera Kentaroh
• Ninomiya Hiromichi
• Shakuto Masahiko
• Iwasaki Takuma
• Teraji Hajime
• Sawada Daisuke
• Ricoh Co Ltd

Inventors

• Nodera Kentaroh
• Ninomiya Hiromichi
• Shakuto Masahiko
• Iwasaki Takuma
• Teraji Hajime
• Sawada Daisuke

Classifications

• G03G15/16

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

• G03G21/0005 Primary

  for removing solid developer or debris from the electrographic recording medium · CPC title

• G03G21/1832

  Shielding members, shutter, e.g. light, heat shielding, prevention of toner scattering · CPC title

• G03G21/08 Primary

  using optical radiation · CPC title

• G03G15/05 Primary

  for imagewise charging, e.g. photoconductive control screen or optically activated charging means · CPC title