Image forming apparatus

Patent metadata

Field	Value
Publication number	US-9738478-B2
Application number	US-201615087309-A
Country	US
Kind code	B2
Filing date	Mar 31, 2016
Priority date	Mar 31, 2015
Publication date	Aug 22, 2017
Grant date	Aug 22, 2017

Abstract

An image forming apparatus, having a housing with an opening, an image forming unit, a path to guide a recording medium toward the opening, a reversible roller disposed in the path, and an intermediate reversible roller disposed between the image forming unit and the reversible roller, is provided. A rotating direction of the reversible roller is switchable between a first rotating direction and a second rotating direction opposite from the first rotating direction. A circumferential speed of the reversible roller is switchable between a predetermined circumferential speed and none. A rotating direction of the intermediate reversible roller is switchable between a third rotating direction and a fourth rotating direction opposite from the third rotating direction. The circumferential speed of the reversible roller in the first rotating direction is reduced to be lower than the predetermined circumferential speed while the intermediate reversible roller is rotating in the third rotating direction.

First claim

What is claimed is:

1. An image forming apparatus, comprising:
a housing formed to have a first opening;
an image forming unit;
a first path formed to guide a recording medium conveyed through the image forming unit toward the first opening;
a reversible roller disposed in the first path, the reversible roller being configured to rotate in a first rotating direction, in which the recording medium is conveyed toward the first opening, and a second rotating direction opposite from the first rotating direction, a circumferential speed of the reversible roller ranging between a predetermined circumferential speed and none; and
an intermediate reversible roller disposed between the image forming unit and the reversible roller in the first path, the reversible roller being configured to rotate in a third rotating direction, in which the recording medium is conveyed from the image forming unit toward the reversible roller, and a fourth rotating direction opposite from the third rotating direction,
wherein the circumferential speed of the reversible roller in the first rotating direction is reduced to be lower than the predetermined circumferential speed while the intermediate reversible roller is rotating in the third rotating direction.

2. The image forming apparatus according to claim 1 , wherein the circumferential speed of the reversible roller in the first rotating direction is reduced to none while the intermediate reversible roller is rotating in the third rotating direction.

3. The image forming apparatus according to claim 1 ,
wherein the image forming unit comprises a fixing device configured to fix a toner image formed on the recording medium thereat; and
wherein the reversible roller is configured to rotate in the first rotating direction when the intermediate reversible roller rotates in the third rotating direction to convey the recording medium toward the reversible roller and to start rotating in the second rotating direction after the recording medium conveyed through the image forming unit exits the intermediate reversible roller.

4. The image forming apparatus according to claim 1 , wherein the reversible roller is configured to start rotating in the second rotating direction after the intermediate reversible roller rotated in the third rotating direction starts rotating in the fourth rotating direction.

5. The image forming apparatus according to claim 1 ,
wherein the housing is formed to have a second opening, the second opening being formed in a lower position than the first opening to open toward a same side as the first opening, and a second path formed to guide the recording medium exiting the image forming unit; and
wherein the image forming apparatus further comprises an exit roller disposed in the second path and configured to convey the recording medium from the image forming unit toward the second opening.

6. The image forming apparatus according to claim 5 ,
wherein the first path and the second path are formed alongside each other in a direction orthogonal to a vertical direction;
wherein the image forming apparatus further comprises an outlet tray disposed on an opposite side from the exit roller across the second opening in the orthogonal direction; and
wherein the reversible roller is spaced apart farther than the exit roller from the outlet tray in the orthogonal direction.

7. The image forming apparatus according to claim 5 , further comprising:
a switching member configured to move between a first guiding position, in which the recording medium is guided to the first path, and a second guiding position, in which the recording medium is guided to the second path.

8. The image forming apparatus according to claim 5 , further comprising:
an intermediate exit roller disposed between the exit roller and the image forming unit in the second path, the intermediate exit roller being configured to convey the recording medium from the image forming unit toward the exit roller,
wherein a distance between the reversible roller and the intermediate reversible roller along the first path is longer than a distance between the exit roller and the intermediate exit roller along the second path.

9. The image forming apparatus according to claim 1 , further comprising:
an outlet tray disposed above the image forming unit,
wherein the first path is formed to extend upward from the image forming unit and curve toward the outlet tray.

10. The image forming apparatus according to claim 1 ,
wherein the first path includes a first guiding part and a second guiding part, the second guiding part being disposed in a position closer than the first guiding part to the image forming unit and arranged to face the first guiding part; and
wherein a curvature radius in the first guiding part is smaller than a curvature radius in the second guiding part in a view along a direction of a rotation axis of the reversible roller.

11. The image forming apparatus according to claim 10 ,
wherein the intermediate reversible roller comprises a first intermediate reversible roller and a second intermediate reversible roller arranged to face the first intermediate reversible roller, the first intermediate reversible roller and the second intermediate reversible roller forming a nipping section to nip the recording medium; and
wherein a tangent at the nipping section in the view along the direction of the rotation axis of the reversible roller inclines to extend upward to be farther from the first opening.

12. The image forming apparatus according to claim 1 , further comprising:
a sensor disposed between the image forming unit and the intermediate reversible roller in the first path, the sensor being configured to detect the recording medium,
wherein behavior of the reversible roller is selected among rotation in the first rotating direction, rotation in the second rotating direction, and stoppage, depending on detection of the recording medium by the sensor.

13. The image forming apparatus according to claim 12 ,
wherein the reversible roller rotating in the first rotating direction is stopped after elapse of a first predetermined length of time from detection of the recording medium by the sensor, and after elapse of a second predetermined length of time from stoppage of the reversible roller, the reversible roller is rotated in the second rotating direction; and
wherein the intermediate reversible roller rotated in the third rotating direction is starts rotating in the fourth rotating direction after elapse of a third predetermined length of time from the detection of the recording medium by the sensor.

14. The image forming apparatus according to claim 1 , wherein the reversible roller rotated in the first rotating direction starts rotating in the second rotating direction without conveying the recording medium beyond the reversible roller.

15. The image forming apparatus according to claim 1 , further comprising:
a first drive source configured to cause rotation of the reversible roller in the first rotating direction and in the second rotating direction and control the circumferential speed of the reversible roller to be driven between the predetermined circumferential speed and none; and
a second drive source configured to cause the intermediate reversible roller to rotate in the third rotating direction and in the fourth rotating direction,
wherein the first drive source controls the circumferential speed of the reversible roller in the first rotating direction to be reduced lower than the predetermined circumferential speed while the intermediate reversible roller is rotating in the thir

Assignees

• Brother Ind Ltd

Inventors

• Makino Masato

Classifications

• B65H29/58

  Article switches or diverters · CPC title

• B65H2801/12

  Single-function printing machines, typically table-top machines · CPC title

• B65H29/125 Primary

  between two sets of rollers · CPC title

• B65H29/14

  and introducing into a pile · CPC title

• B65H2404/612

  and shaped for curvilinear transport path · CPC title