Image forming apparatus

Patent metadata

Field	Value
Publication number	US-9316985-B2
Application number	US-201414553682-A
Country	US
Kind code	B2
Filing date	Nov 25, 2014
Priority date	Nov 25, 2013
Publication date	Apr 19, 2016
Grant date	Apr 19, 2016

Abstract

An image forming apparatus includes a transfer unit configured to transfer a developing agent image onto a sheet, a fixing unit configured to fix the developing agent image onto the sheet, a discharge tray configured to receive the sheet having the developing agent image thereon, at least one pair of discharge rollers disposed downstream of the fixing unit in a conveying direction and configured to discharge the sheet toward the discharge tray, and at least one pair of conveying rollers disposed at a conveying path extending between the fixing unit and the at least one pair of discharge rollers. The at least one pair of conveying rollers is configured to convey the sheet toward the at least one discharge rollers in the conveying direction and to form the sheet into a corrugated shape having at least one of a ridge portion and a groove portion in a sheet thickness direction.

First claim

What is claimed is:

1. An image forming apparatus comprising:
a transfer unit configured to transfer a developing agent image onto a sheet;
a fixing unit comprising a heating member configured to thermally fix the developing agent image onto the sheet, and a pressing member configured to press the sheet against the heating member;
a discharge tray configured to receive the sheet having the developing agent image fixed thereon;
at least one pair of switchback rollers disposed upstream of the discharge tray in a conveying direction, the at least one pair of switchback rollers being configured to discharge the sheet having the developing agent image fixed thereon in the conveying direction toward the discharge tray and then switch back the sheet toward the transfer unit along a return path in a direction reverse to the conveying direction; and
a corrugation system disposed away from the return path and at a conveying path extending between the fixing unit and the at least one pair of switchback rollers, the corrugation system including at least one pair of conveying rollers configured to convey the sheet passing out of the fixing unit toward the at least one pair of switchback rollers along the conveying path in the conveying direction and to form the sheet passing out of the fixing unit into a corrugated shape having at least one of a ridge portion and a groove portion in a sheet thickness direction,
wherein the at least one pair of conveying rollers includes a first pair of conveying rollers and the corrugation system further includes a shaft that supports one roller of the first pair of conveying rollers, the shaft including a protrusion configured to contact an end portion, in a sheet width direction, of the sheet passing out of the fixing unit and to form the sheet passing out of the fixing unit into the corrugated shape, the sheet width direction being perpendicular to the conveying direction, and
wherein the protrusion has a flange shape and protrudes radially from the shaft of the corrugation system.

2. The image forming apparatus according to claim 1 , wherein the one roller of the first pair of conveying rollers and the pressing member are positioned on a same side of the conveying path.

3. The image forming apparatus according to claim 1 , wherein the at least one pair of switchback rollers is vertically spaced from the fixing unit, the conveying path being curved in a U-shape, and the at least one pair of conveying rollers of the corrugation system is downstream of the fixing unit and upstream of an inflection point of the conveying path in the conveying direction.

4. The image forming apparatus according to claim 1 , wherein the at least one pair of conveying rollers of the corrugation system includes a conveying roller including a rubber portion configured to contact the sheet passing out of the fixing unit, and a conveying roller including a resin portion configured to contact the sheet passing out of the fixing unit, the resin portion having a lower frictional force than the rubber portion.

5. The image forming apparatus according to claim 4 , wherein the pressing member and the conveying roller having the rubber portion are positioned on a same side of the conveying path.

6. The image forming apparatus according to claim 1 , further comprising a guide member configured to define a part of the conveying path and guide the sheet, the guide member including a plurality of ribs projecting toward the sheet passing out of the fixing unit and extending in the conveying direction, and an imaginary line connecting distal ends of the plurality of ribs extending along the corrugated shape formed in the sheet.

7. The image forming apparatus according to claim 1 , wherein the at least one pair of switchback rollers is configured to form the sheet having the developing agent image fixed thereon into a corrugated shape having at least one of a ridge portion and a groove portion in the sheet thickness direction.

8. The image forming apparatus according to claim 1 , wherein the conveying path is branched into the return path at a position downstream of the at least one pair of conveying rollers and upstream of the at least one pair of switchback rollers in the conveying direction.

9. The image forming apparatus according to claim 1 , further comprising a housing and a guide member configured to pivot, relative to the housing, about a lower end portion thereof between a first position and a second position, the guide member when in the first position defining a part of the conveying path, and the guide member when in the second position exposing the conveying path and guiding the sheet conveyed from the fixing unit toward an exterior of the housing.

10. An image forming apparatus comprising:
a transfer unit configured to transfer a developing agent image onto a sheet;
a fixing unit comprising a heating member configured to thermally fix the developing agent image onto the sheet, and a pressing member configured to press the sheet against the heating member;
a discharge tray configured to receive the sheet having the developing agent image fixed thereon;
at least one pair of discharge rollers disposed upstream of the discharge tray in a conveying direction and configured to discharge the sheet having the image fixed thereon toward the discharge tray; and
a corrugation system disposed at a conveying path extending between the fixing unit and the at least one pair of discharge rollers, the corrugation system including at least one pair of conveying rollers configured to convey the sheet passing out of the fixing unit toward the at least one pair of discharge rollers along the conveying path in the conveying direction and to form the sheet passing out of the fixing unit into a corrugated shape having at least one of a ridge portion and a groove portion in a sheet thickness direction,
wherein the at least one pair of conveying rollers of the corrugation system includes a rubber driving roller and a resin driven roller having a lower frictional force than the rubber driving roller, and the resin driven roller of the corrugation system and the heating member of the fixing unit are positioned on a same side of the conveying path, and
wherein the corrugation system further includes a resin shaft that supports the rubber driving roller, the resin shaft including a resin protrusion configured to contact an end portion, in a sheet width direction, of the sheet passing out of the fixing unit and to form the sheet passing out of the fixing unit into the corrugated shape, the sheet width direction being perpendicular to the conveying direction.

11. The image forming apparatus according to claim 10 , wherein the fixing unit supports the resin driven roller of the corrugation system.

12. The image forming apparatus according to claim 10 , wherein the rubber driving roller of the corrugation system and the pressing member of the fixing unit are positioned on a same side of the conveying path.

Assignees

• Brother Ind Ltd

Inventors

• Miwa Atsushi

Classifications

• B65H2301/5122

  Corrugating; Stiffening · CPC title

• B65H2404/612

  and shaped for curvilinear transport path · CPC title

• B65H2404/1317

  End profile · CPC title

• B65H2402/45

  Doors · CPC title

• B65H2301/51214

  parallel to direction of displacement of handled material · CPC title