Image Forming Apparatus

• US 20160289037A1
• Filed: 03/31/2016
• Published: 10/06/2016
• Est. Priority Date: 03/31/2015
• Status: Active Grant

• Current Assignee: Brother Kogyo Kabushiki Kaisha
• Original Assignee: Brother Kogyo Kabushiki Kaisha
• Inventors: Makino, Masato
• Granted Patent: US 9,738,478 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B65H 2220/02 indicating an entity which is controlled, adjusted or changed by a control process, i.e. output
• CPC Class Codes: B65H 2220/11 indicating that the input or output entities exclusively relate to machine elements
• CPC Class Codes: B65H 2301/33312 forward reverse rollers pairs
• CPC Class Codes: B65H 2404/612 and shaped for curvilinear transport path
• CPC Class Codes: B65H 2404/632 Wedge member
• CPC Class Codes: B65H 2511/514 Particular portion of element
• CPC Class Codes: B65H 2513/11 angular
• CPC Class Codes: B65H 2701/1311 leading edge
• CPC Class Codes: B65H 2801/12 Single-function printing machines, typically table-top machines
• CPC Class Codes: B65H 29/125 between two sets of rollers
• CPC Class Codes: B65H 29/14 and introducing into a pile
• CPC Class Codes: B65H 29/58 Article switches or diverters
• CPC Class Codes: B65H 43/08 Photoelectric devices
• CPC Class Codes: B65H 85/00 Recirculating articles, i.e. feeding each article to, and delivering it from, the same machine work-station more than once

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.

Claims

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, a rotating direction of the reversible roller being switchable between 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 being switchable 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, a rotating direction of the intermediate reversible roller being switchable between 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 switched 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 sheet thereat;

and

wherein the rotating direction of the reversible roller is switched from the first rotating direction to 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 switched to rotate in the second rotating direction after the rotation of the intermediate reversible roller in the third rotating direction is switched to 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 1,

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 roller and the second intermediate reversible roller forming a nipping section to nip the recording sheet;

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 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 sheet 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 rotating in the third rotating direction is switched to rotate in the fourth rotating direction after elapse of a third predetermined length of time from the detection of the recording sheet by the sensor.

14. The image forming apparatus according to claim 1,

wherein the rotating direction of the reversible roller is switched from the first rotating direction to the second rotating direction without conveying the recording medium beyond the reversible roller.