SHEET FEEDING DEVICE AND IMAGE FORMING APPARATUS

Abstract

The present invention relates to a sheet feeding device includes a sheet tray 2 to place sheets thereon, a nozzle 9 which blows air onto the sheets supported by the sheet tray 2, a conveyance belt 10 to adsorb and convey a sheet floated by blowing air by the nozzle 9, a pulling roller pair 16 which is arranged on a downstream side of the conveyance belt in a sheet conveyance direction and conveys the sheet conveyed by the conveyance belt 10, and a conveyance guide 17 which guides the sheet conveyed from the conveyance belt 10 to the pulling roller pair 16. The conveyance guide 17 has slope portions 17a, 17b which are sloped from an upstream side in the sheet conveyance direction to the downstream side to extend from a central portion in a sheet width direction perpendicular to the sheet conveyance direction to both the end portions.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front explanatory view of a conveyance guide.

FIG. 2 is an upper explanatory view of the conveyance guide.

FIG. 3 is an explanatory view showing a state in which a hanged-down sheet is guided by the conveyance guide.

FIG. 4 is an explanatory view showing a state in which the hanged-down sheet is guided by the conveyance guide.

FIG. 5 is a schematic sectional view for explaining an image forming apparatus having a sheet feeding device.

FIG. 6 is a schematic sectional view for explaining the sheet feeding device.

FIG. 7 is a schematic sectional view for explaining the sheet feeding device.

FIG. 8 is a schematic sectional view for explaining the sheet feeding device.

FIG. 9 is a partial sectional view for explaining an air paper-feeding mechanism.

FIG. 10 is a schematic view for explaining a conventional sheet feeding device.

FIG. 11 is a view for explaining a state in which a conventional sheet is guided.

FIG. 12 is a view for explaining a state in which a conventional sheet is guided.

FIG. 13 is a view for explaining a state in which a conventional sheet is guided.

Claims

1. A sheet feeding device having a mechanism which blows air onto stacked sheets and floats the sheets to loosen the sheets, comprising: a sheet storing portion to store sheets;an air blowing portion which blows air onto the sheets stored in the sheet storing portion;an adsorption/conveyance portion to adsorb and convey a sheet floated by blowing air by the air blowing portion;a sheet conveyance portion which is arranged on a downstream side of the adsorption/conveyance portion in a sheet conveyance direction and which conveys the sheet conveyed by the adsorption/conveyance portion to the downstream side; anda conveyance guide which guides the sheet conveyed from the adsorption/conveyance portion to the sheet conveyance portion;wherein the conveyance guide has a slope portion which is sloped from the upstream side in the sheet conveyance direction to the downstream side according to extend from a sheet conveyance center in a sheet width direction perpendicular to the sheet conveyance direction to both side end portions.

2. The sheet feeding device according to claim 1, wherein a level of an upstream-side end portion of the conveyance guide in the sheet conveyance direction is set to be lower than a sheet conveyance surface which is adsorbed and conveyed by the adsorption/conveyance portion.

3. The sheet feeding device according to claim 1, wherein an end portion of the slope portion of the conveyance guide which is in contact with the sheet is formed symmetrically about a sheet conveyance center in the sheet width direction.

4. The sheet feeding device according to claim 1, wherein the conveyance guide is arranged almost horizontally.

5. The sheet feeding device according to claim 1, wherein both end portions of the slope portion of the conveyance guide are located outside a maximum sheet width in which the sheet can be conveyed in the sheet width direction.

6. The sheet feeding device according to claim 1, wherein the slope portion of the conveyance guide is formed in a straight shape.

7. The sheet feeding device according to claim 1, wherein the upstream-side end portion of the slope portion in the sheet conveyance direction is subjected to a bending process.

8. An image forming apparatus including a sheet feeding device having a mechanism which blows air onto stacked sheets and floats the sheets to loosen the sheets, comprising: a sheet storing portion to store sheets;an air blowing portion which blows air onto the sheets stored in the sheet storing portion;an adsorption/conveyance portion to adsorb and convey a sheet floated by blowing air by the air blowing portion;a sheet conveyance portion which is arranged on a downstream side of the adsorption/conveyance portion in a sheet conveyance direction and which conveys the sheet conveyed by the adsorption/conveyance portion to the downstream side; anda conveyance guide which guides the sheet conveyed from the adsorption/conveyance portion to the sheet conveyance portion; andwherein the conveyance guide has a slope portion which is sloped from the upstream side in the sheet conveyance direction to the downstream side according to extend from a sheet conveyance center in a sheet width direction perpendicular to the sheet conveyance direction to both side end portions.