초록 ▼

The present invention is to provide a paper stacker for use with an image forming apparatus of a high copying speed. The paper stacker comprises a paper conveying means for conveying a paper with an image recorded thereon to a stacking position, a top end stopper provided reciprocatively movably alo

The present invention is to provide a paper stacker for use with an image forming apparatus of a high copying speed. The paper stacker comprises a paper conveying means for conveying a paper with an image recorded thereon to a stacking position, a top end stopper provided reciprocatively movably along a conveying path of the paper, a paper receiving plate disposed below the conveying path of the paper for receiving a paper, a rear end stopper for defining the rear end position of the paper on the paper receiving plate, and an elevating device for changing the height of the paper receiving plate, wherein the top end stopper and the rear end stopper are provided movably in the same direction in the conveyance direction per a given number of papers. The papers are stacked only by shifting the top end stopper and the rear end stopper in the conveyance direction so that the stacker configuration is extremely simplified so as to enable a high speed.

대표청구항 ▼

What is claimed is: 1. A paper stacker for use with an image forming apparatus comprising: paper conveying means for conveying paper with an image recorded thereon in a paper conveyance direction to a stacking position; a top end stopper arranged on an extreme forward position of a conveyance path

What is claimed is: 1. A paper stacker for use with an image forming apparatus comprising: paper conveying means for conveying paper with an image recorded thereon in a paper conveyance direction to a stacking position; a top end stopper arranged on an extreme forward position of a conveyance path of the paper in said stacking position for defining a top end position of the paper to be stacked; a paper receiving plate arranged below the paper conveyance path in the stacking position for receiving papers thereon in a state where the papers are alternatively shifted in a direction parallel to the paper conveyance direction; a rear end stopper arranged on a backward position of the paper conveyance path in the stacking position for defining a rear end position of the paper to be stacked; and lifting means for moving up and down said paper receiving plate, wherein said top end stopper and said rear end stopper are movable in association with each other in the same direction, either in the paper conveyance direction or in a direction opposite the paper conveyance direction to create shifted stacks of paper alternating in a direction parallel to the paper conveyance direction. 2. The paper stacker according to claim 1, wherein said paper conveying means comprises a circulating belt. 3. The paper stacker according to claim 1, wherein paper gripping means for gripping a front end of the paper is mounted on said paper conveying means. 4. The paper stacker according to claim 2, wherein a pair of paper gripping means are mounted on opposite positions of said circulating belt. 5. The paper stacker according to claim 1, wherein said top end stopper is mounted on reciprocating means capable of reciptrocatively movable in the paper conveyance direction. 6. The paper stacker according to claim 5, wherein said reciprocating means comprises a belt. 7. The paper stacker according to claim 1, wherein at least one of said top end stopper and said rear end stopper is movable in association with a size of the paper in the paper conveyance direction. 8. The paper stacker according to claim 1, wherein one of said top end stopper and said rear end stopper is movable in the paper conveyance direction to cause the paper to collide against the other of said stoppers in the end thereof while the paper falls onto said paper receiving plate in the stacking position. 9. A paper stacker comprising paper gripping means for gripping the top end of a paper after image formation and for conveying the paper in a paper conveyance direction; circulating means for supporting and circulating the paper gripping means; a top end stopper provided reciprocatively movably on the circulation path of the paper gripping means for determining the top end position of the paper; a paper placing plate provided below the circulation path of the paper gripping means for receiving a paper separated by the top end stopper and dropped from the paper gripping means; a rear end stopper for determining the rear end position of the paper on the paper placing plate; and an elevating device for changing the relative height of the paper placing plate and the circulating means, wherein the top end stopper and the rear end stopper are provided movably in the same direction in the paper conveyance direction to create shifted stacks of paper in a direction parallel to the paper conveyance direction. 10. A paper stacker for use with an image forming apparatus comprising: a paper conveyor, which conveys paper with an image recorded thereon to a stacking position; a top end stopper arranged on an extreme forward position of a conveyance path of the paper in the stacking position for defining a top end position of the paper to be stacked; a paper receiving plate arranged below the paper conveyance path in the stacking position for receiving papers thereon in a state where the papers are alternatively shifted in a direction parallel to the paper conveyance; and a rear end stopper arranged on a backward position of the paper conveyance path in the stacking position for defining a rear end position of the paper to be stacked, wherein the top end stopper and the rear end stopper are movable in association with each other in the same direction, either in the direction of the paper conveyance or in a direction opposite to the paper conveyance, to create shifted stacks of paper alternating in a direction parallel to the paper conveyance. 11. The paper stacker of claim 10, wherein the paper conveyor comprises a circulating belt. 12. The paper stacker of claim 10, wherein a paper gripper, which grips a front end of the paper is mounted on the paper conveyor. 13. The paper stacker of claim 11, wherein a pair of paper gripper are mounted on opposite positions of the circulating belt. 14. The paper stacker of claim 10, wherein the top end stopper is mounted on a reciprocating member capable of reciprocatively movable in the paper conveyance direction. 15. The paper stacker of claim 14, wherein the reciprocating member comprises a belt. 16. The paper stacker of claim 10, wherein at least one of the top end stopper and the rear end stopper is movable in association with a size of the paper in the direction of conveyance thereof. 17. The paper stacker of claim 10, wherein one of the top end stopper and the rear end stopper is movable in the paper conveyance direction to cause the paper to collide against the other of the stoppers in the end thereof while the paper falls onto the paper receiving plate in the stacking position. 18. A paper stacker comprising; a paper gripper, which grips the top end of a paper after image formation and conveys the paper in a paper conveyance direction; a circulating mechanism, which supports and circulates the paper gripper; a top end stopper provided reciprocatively movably on a circulation path of the paper gripper for determining the top end position of the paper; a paper placing plate provided below the circulation path of the paper gripper for receiving a paper separated by the top end stopper and dropped from the paper gripper, and a rear end stopper for determining the rear end position of the paper on the paper placing plate, wherein the top end stopper and the rear end stopper are provided movably in the same direction as the paper conveyance direction to create shifted stacks of paper in a direction parallel to the paper conveyance direction.