Medium discharge device and image forming apparatus

Patent metadata

Field	Value
Publication number	US-9212017-B2
Application number	US-201414314772-A
Country	US
Kind code	B2
Filing date	Jun 25, 2014
Priority date	Jun 26, 2013
Publication date	Dec 15, 2015
Grant date	Dec 15, 2015

Abstract

A medium discharge device includes: a discharge tray having a placing surface on which a medium is to be placed; a first pair of discharge rollers configured to rotate about axes to discharge the medium through a first nip onto the discharge tray; a second pair of discharge rollers configured to rotate about the axes to discharge the medium through a second nip onto the discharge tray; and a discharge guide for guiding the discharged medium. The discharge guide includes a first projection between the first and second pairs of discharge rollers, and a second projection on an opposite side of the first projection with respect to the first pair of discharge rollers. Each of the first and second projections projects to the placing surface side relative to the first and second nips and has a guide surface opposite to the placing surface.

First claim

What is claimed is:

1. A medium discharge device comprising:
a discharge tray having a placing surface on which a medium is to be placed;
a first pair of discharge rollers configured to form a first nip between the first pair of discharge rollers, and rotate about respective axes parallel to each other to discharge the medium through the first nip in a discharging direction onto the discharge tray;
a second pair of discharge rollers configured to form a second nip between the second pair of discharge rollers, and rotate about the respective axes to discharge the medium through the second nip in the discharging direction onto the discharge tray; and
a discharge guide for guiding the medium discharged by the first pair of discharge rollers and the second pair of discharge rollers, the discharge guide including:
a first projection disposed between the first pair of discharge rollers and the second pair of discharge rollers in an axial direction parallel to the axes, the first projection projecting toward the placing surface relative to the first and second nips and having a first guide surface; and
a second projection disposed on an opposite side of the first projection with respect to the first pair of discharge rollers in the axial direction, the second projection projecting toward the placing surface relative to the first and second nips and having a second guide surface;

wherein each of the first and second guide surfaces extends from an upstream side to a downstream side of the first and second nips in the discharging direction; and
wherein on the downstream side of the first and second nips, the first guide surface has an area inclined to a discharge plane passing through the first and second nips and being perpendicular to a virtual line perpendicularly intersecting the axes so as to separate from the discharge plane downstream in the discharging direction;
wherein on the downstream side of the first and second nips, the second guide surface is parallel to the discharge plane, or is inclined to the discharge plane so as to approach the discharge plane downstream in the discharging direction.

2. The medium discharge device of claim 1 , wherein a difference between a projecting amount by which the first projection projects toward the placing surface relative to the first nip and a projecting amount by which the second projection projects toward the placing surface relative to the first nip increases downstream from the first nip in the discharging direction.

3. The medium discharge device of claim 1 , wherein a first projecting amount by which a downstream end in the discharging direction of the first projection projects toward the placing surface relative to the first nip is greater than a second projecting amount by which a downstream end in the discharging direction of the second projection projects toward the placing surface relative to the first nip.

4. The medium discharge device of claim 1 , wherein the discharge guide further includes a third projection disposed on an opposite side of the first projection with respect to the second pair of discharge rollers in the axial direction, the third projection projecting toward the placing surface relative to the first and second nips and having a third guide surface.

5. The medium discharge device of claim 4 , wherein the discharge guide further includes:
a fourth projection disposed between the first projection and the first pair of discharge rollers in the axial direction, the fourth projection projecting toward the placing surface relative to the first and second nips and having a fourth guide surface; and
a fifth projection disposed between the first projection and the second pair of discharge rollers in the axial direction, the fifth projection projecting toward the placing surface relative to the first and second nips and having a fifth guide surface.

6. The medium discharge device of claim 5 , wherein each of the third to fifth guide surfaces extends from an upstream side to a downstream side of the first and second nips in the discharging direction.

7. The medium discharge device of claim 6 , wherein on the downstream side of the first and second nips, each of the third to fifth guide surfaces is parallel to the discharge plane, or is inclined to the discharge plane so as to approach the discharge plane downstream in the discharging direction.

8. An image forming apparatus comprising the medium discharge device of claim 1 .

9. A medium discharge device comprising:
a discharge tray having a placing surface on which a medium is to be placed;
a first pair of discharge rollers configured to form a first nip between the first pair of discharge rollers, and rotate about respective axes parallel to each other to discharge the medium through the first nip in a discharging direction onto the discharge tray;
a second pair of discharge rollers configured to form a second nip between the second pair of discharge rollers, and rotate about the respective axes to discharge the medium through the second nip in the discharging direction onto the discharge tray; and
a discharge guide for guiding the medium discharged by the first pair of discharge rollers and the second pair of discharge rollers, the discharge guide including;
a first projection disposed between the first pair of discharge rollers and the second pair of discharge rollers in an axial direction parallel to the axes, the first projection projecting toward the placing surface relative to the first and second nips and having a first guide surface; and
a second projection disposed on an opposite side of the first projection with respect to the first pair of discharge rollers in the axial direction, the second projection projecting toward the placing surface relative to the first and second nips and having a second guide surface;

wherein the first and second projections are disposed slidably in a direction in which a virtual line perpendicularly intersecting the axes extends, and urged toward the placing surface.

10. The medium discharge device of claim 9 , wherein the first and second projections are formed separately from each other and individually urged.

11. The medium discharge device of claim 9 , wherein each of the first and second guide surfaces extends from an upstream side to a downstream side of the first and second nips in the discharging direction.

12. The medium discharge device of claim 11 , wherein on the downstream side of the first and second nips, the second guide surface is parallel to a discharge plane passing through the first and second nips and being perpendicular to the virtual line, or is inclined to the discharge plane so as to approach the discharge plane downstream in the discharging direction.

13. The medium discharge device of claim 11 , wherein on the downstream side of the first and second nips, the first guide surface has an area inclined to a discharge plane passing through the first and second nips and being perpendicular to the virtual line so as to separate from the discharge plane downstream in the discharging direction.

14. An image forming apparatus comprising the medium discharge device of claim 9 .

15. A medium discharge device comprising:
a discharge tray having a placing surface on which a medium is to be placed;
a first pair of discharge rollers including a first roller that rotates about a first axis extending in a first direction and a second roller that rotates about a second axis extending in the first direction, the first roller and the second roller forming a first nip between the first roller and the second roller, the first pair of discharge rollers

Assignees

• Oki Data Kk

Inventors

• Furusawa Yasunori

Classifications

• B65H29/52

  Stationary guides or smoothers · CPC title

• B65H29/125 Primary

  between two sets of rollers · CPC title

• B65H29/70

  Article bending or stiffening arrangements · CPC title

• G03G15/6552

  Means for discharging uncollated sheet copy material, e.g. discharging rollers, exit trays · CPC title

• B65H2301/5122

  Corrugating; Stiffening · CPC title