Image forming apparatus

Patent metadata

Field	Value
Publication number	US-9561925-B2
Application number	US-201514884069-A
Country	US
Kind code	B2
Filing date	Oct 15, 2015
Priority date	Oct 17, 2014
Publication date	Feb 7, 2017
Grant date	Feb 7, 2017

Abstract

An image forming apparatus, including a main chassis having a discharge tray and a switchback tray in an upper position with respect to the discharge tray; an image forming unit; a discharge roller to discharge a recording sheet conveyed through the image forming unit onto the discharge tray; a duplex conveyer to invert the sheet and convey the inverted sheet to return to the image forming unit; and a switchback roller being rotatable in a normal direction to convey the sheet toward the switchback tray and a reverse direction to convey the sheet to the duplex conveyer; is provided. The main chassis includes a pair of walls, each of which extends in a vertical direction and in a conveying direction of the sheet and is arranged in adjacent to the switchback tray such that the switchback tray is interposed between the pair of walls.

First claim

What is claimed is:

1. An image forming apparatus, comprising:
a main chassis comprising a discharge tray and a switchback tray disposed in an upper position with respect to the discharge tray;
an image forming unit configured to form an image on a recording sheet;
a discharge roller configured to discharge the recording sheet conveyed through the image forming unit onto the discharge tray; and
a duplex conveyer comprising a switchback roller, the switchback roller being configured to be rotatable in a normal direction and a reverse direction, the switchback roller being configured to convey the recording sheet conveyed through the image forming unit toward the switchback tray by rotating in the normal direction and to convey the recording sheet being conveyed toward the switchback tray to return to the image forming unit by rotating in the reverse direction, the duplex conveyer being configured to invert the recording sheet conveyed through the image forming unit and convey the inverted recording sheet to return the image forming unit by switching rotation directions of the switchback roller;
wherein the main chassis comprises a pair of walls, each of which extends in a vertical direction and in a conveying direction being a direction to convey the recording sheet by the switchback roller rotating in the normal direction toward the switchback tray, the pair of walls being arranged in adjacent to the switchback tray such that the switchback tray is interposed between the pair of walls.

2. The image forming apparatus according to claim 1 , further comprising:
a guide disposed in a position between the switchback roller and the switchback tray, the guide being configured to guide the recording sheet conveyed by the switchback roller toward the switchback tray, the guide being arranged to overlap the pair of walls in a view along a direction of rotation axis of the switchback roller.

3. The image forming apparatus according to claim 2 ,
wherein an upper end of each of the pair of walls is in an upper position with respect to an upper end of the guide.

4. The image forming apparatus according claim 2 ,
wherein the main chassis comprises an upper discharge tray disposed in an upper position with respect to the switchback roller, and
wherein the guide is movable between a first position, in which the recording sheet is conveyed toward the switchback tray, and a second position, in which the recording sheet is conveyed toward the upper discharge tray.

5. The image forming apparatus according to claim 4 ,
wherein the upper discharge tray is arranged to extend in the vertical direction.

6. The image forming apparatus according to claim 5 ,
wherein an upper part of the upper discharge tray inclines with respect to the vertical direction.

7. The image forming apparatus according to claim 4 ,
wherein the guide comprises a comb-teeth section;
wherein the upper discharge tray comprises a plurality of slits, in which the comb-teeth section is inserted when the guide is in the first position.

8. The image forming apparatus according to the claim 2 ,
wherein the guide comprises:
a rotation shaft;
a pair of extended parts extending from axial ends of the rotation shaft in a radial direction of the rotation shaft;
a connector part connecting radial ends of the pair of extended parts with each other; and
a plurality of guiding parts arranged to extend from the connector part in a direction to intersect with the radial direction.

9. The image forming apparatus according to claim 8 ,
wherein the switchback tray comprises a rib extending from an edge thereof on a downstream side with regard to the conveying direction, the rib extending downstream in the conveying direction, the rib being arranged to overlap the discharge tray in a view along the vertical direction.

10. The image forming apparatus according to claim 9 ,
wherein the rib is disposed at each end on the edge of the switchback tray along an axial direction of the discharge roller.

11. The image forming apparatus according to claim 1 , further comprising:
a reader unit configured to read an image of an original sheet, the reader unit being supported by the pair of walls.

12. The image forming apparatus according to claim 1 , further comprising:
a connecting wall configured to connect the pair of walls with each other at a position between the reader unit and the switchback tray,
wherein the connecting wall forms an aperture, through which air is allowed to flow in an extending direction for the pair of walls.

13. The image forming apparatus according to claim 1 ,
wherein a downstream end of each of the pair of walls with regard to the conveying direction is on a same side as the discharge tray with respect to the discharge roller.

14. The image forming apparatus according to claim 1 ,
wherein a height of each of the pair of walls from a placement surface of the switchback tray is in a range between 10 mm and 100 mm.

15. The image forming apparatus according to claim 1 ,
wherein a height of each of the pair of walls from a placement surface of the switchback tray is in a range between 20 mm and 80 mm.

16. The image forming apparatus according to claim 1 ,
wherein a length of each of the pair of walls along the conveying direction is in a range between 20 mm and 200 mm.

17. The image forming apparatus according to claim 1 ,
wherein a length of each of the pair of walls along the conveying direction is in a range between 40 mm and 160 mm.

18. The image forming apparatus according to claim 1 ,
wherein the switchback tray comprises a plurality of ribs protruding upward and arranged on an upstream end of the switchback tray with regard to the conveying direction.

19. The image forming apparatus according to claim 18 ,
wherein each of the plurality of ribs comprises:
a first part, an upper edge of which extends in a horizontal direction;
a second part comprising an extending from a downstream end of the first part with regard to the conveying direction to incline downward; and
a third part, which extends from an upstream end of the first part with regard to the conveying direction to curve downward to reach the switchback roller.

Assignees

• Brother Ind Ltd

Inventors

• Sato Shougo

Classifications

• B65H2404/693

  Retractable guiding means, i.e. between guiding and non guiding position · CPC title

• B65H2601/324

  Removability or inter-changeability of machine parts, e.g. for maintenance · CPC title

• B65H2404/63

  Oscillating, pivoting around an axis parallel to face of material, e.g. diverting means · CPC title

• B65H2801/06

  Office-type machines, e.g. photocopiers · CPC title

• B65H2404/6111

  and shaped for curvilinear transport path · CPC title