Sheet feeding device and image forming apparatus

Patent metadata

Field	Value
Publication number	US-9403650-B2
Application number	US-201514607172-A
Country	US
Kind code	B2
Filing date	Jan 28, 2015
Priority date	Jan 29, 2014
Publication date	Aug 2, 2016
Grant date	Aug 2, 2016

Abstract

In a sheet feeding device, when a leading end of a recording sheet is guided to a nip region along a leading end portion of a sheet guide member in contact with a surface of a separation roller, the leading end of the recording sheet slides and moves on surfaces of projected end portions to be guided to the vicinity of the nip region, and the leading end of the recording sheet passes through the nip region quickly. Hence, a sheet feed error is much less likely to occur. Since a distance from recessed end portions to the nip region is longer and the leading end of the recording sheet is in contact with the separation roller for a longer time right after passing the recessed end portions until reaching the nip region, even though a plurality of recording sheets is stacked, the recording sheets are separated one by one by the separation roller, preventing a multi-sheet feed of the sheets.

First claim

What is claimed is:

1. A sheet feeding device comprising:
a sheet feed tray configured to be loaded with sheets;
a sheet guide member;
a sheet feed roller configured to convey the sheets; and
a separation member configured to separate the sheets to prevent a multi-sheet feed of the sheets, the sheets being guided from the sheet feed tray along the sheet guide member to a nip region between the sheet feed roller and the separation member such that the sheets are forwarded through the nip region onto a sheet conveying path; wherein
projected end portions and recessed end portions are alternately arranged on a leading end portion of the sheet guide member in a direction perpendicular or substantially perpendicular to a direction of conveyance of the sheets;
the sheet guide member is directed toward a downstream side in the direction of conveyance;
the projected end portions project toward the downstream side in the direction of conveyance;
the recessed end portions are recessed from the projected end portions toward an upstream side in the direction of conveyance;
the projected end portions are provided at a position opposite to a first end of the separation member, at a position opposite to a second end of the separation member, and at a position opposite to a central portion of the sheet feed roller, and the first end, the central portion, and the second end are spaced apart in the direction perpendicular or substantially perpendicular to the direction of conveyance; and
the projected end portions arranged in the positions opposite to the first end and the second end of the separation member overlap the first end and the second end of the separation member in the direction perpendicular or substantially perpendicular to the direction of conveyance of sheets when viewed in the direction of conveyance.

2. The sheet feeding device according to claim 1 , wherein the projected end portions provided at the positions opposite to the first end and the second end of the separation member are arranged on two sides of the leading end portion of the sheet guide member in the direction perpendicular or substantially perpendicular to the direction of conveyance.

3. The sheet feeding device according to claim 1 , wherein the projected end portions have a smaller width in the direction perpendicular or substantially perpendicular to the direction of conveyance toward the nip region.

4. An image forming apparatus comprising:
the sheet feeding device of claim 1 ; and
a printer configured to form an image on a sheet forwarded by the sheet feeding device.

5. The image forming apparatus according to claim 4 , wherein the projected end portions provided at the positions opposite to the first end and the second end of the separation member are arranged on two sides of the leading end portion of the sheet guide member in the direction perpendicular or substantially perpendicular to the direction of conveyance.

6. The image forming apparatus according to claim 4 , wherein the projected end portions have a smaller width in the direction perpendicular or substantially perpendicular to the direction of conveyance toward the nip region.

7. The sheet feeding device according to claim 1 , wherein one of the projected end portions continuously extends, in a lengthwise direction of the sheet feed roller, from an inner side of a first end of the sheet feed roller to an outer side of the first end of the sheet feed roller, and another one of the projected end portions continuously extends, in the lengthwise direction of the sheet feed roller, from an inner side of a second end of the sheet feed roller to an outer side of the second end of the sheet feed roller.

8. A sheet feeding device comprising:
a sheet feed tray configured to be loaded with sheets;
a sheet guide member;
a sheet feed roller configured to convey the sheets; and
a separation member configured to separate the sheets to prevent a multi-sheet feed of the sheets, the sheets being guided from the sheet feed tray along the sheet guide member to a nip region between the sheet feed roller and the separation member such that the sheets are forwarded through the nip region onto a sheet conveying path; wherein
projected end portions and recessed end portions are alternately arranged on a leading end portion of the sheet guide member in a direction perpendicular or substantially perpendicular to a direction of conveyance of the sheets;
the sheet guide member is directed toward a downstream side in the direction of conveyance;
the projected end portions project toward the downstream side in the direction of conveyance;
the recessed end portions are recessed from the projected end portions toward an upstream side in the direction of conveyance;
the projected end portions are provided at a position opposite to a first end of the separation member, at a position opposite to a second end of the separation member, and at a position opposite to a central portion of the sheet feed roller, and the first end, the central portion, and the second end are spaced apart in the direction perpendicular or substantially perpendicular to the direction of conveyance;
the projected end portions arranged in the positions opposite to the first end and the second end of the separation member overlap the first end and the second end of the separation member in the direction perpendicular or substantially perpendicular to the direction of conveyance of sheets; and
the sheet guide member is a flexible film.

Assignees

• Sharp Kk

Inventors

• Katsura Norichika
• Fukada Yasuaki
• Kobayashi Yoshiyuki
• Kikuchi Yoshiteru

Classifications

• B65H3/66 Primary

  Article guides or smoothers, e.g. movable in operation · CPC title

• B65H3/5215

  the retainers positioned under articles separated from the top of the pile · CPC title

• B65H3/5223

  Retainers of the pad-type, e.g. friction pads · CPC title

• B65H2404/622

  Details of longitudinal profile · CPC title

• B65H3/5261

  Retainers of the roller type, e.g. rollers · CPC title