Sheet feeding device, image reading apparatus including the sheet feeding device, and image forming apparatus

Patent metadata

Field	Value
Publication number	US-2021009372-A1
Application number	US-202016919547-A
Country	US
Kind code	A1
Filing date	Jul 2, 2020
Priority date	Jul 9, 2019
Publication date	Jan 14, 2021
Grant date	—

Abstract

A sheet feeding device includes a stacking portion, a feeding portion, a contact and separation mechanism, a separation conveying portion, a detecting portion, a size acquiring portion, and a controller. In a first mode, in a case that the detecting portion detects passing of a trailing end of the current sheet after the separating operation, the controller causes the contact and separation mechanism to start a contact operation in which the feeding portion is contacted to a sheet stacked on the stacking portion in order to feed a subsequent sheet. In a second mode, before the detecting portion detects passing of a trailing end of the current sheet after the separating operation, the controller causes the contact and separation mechanism to start, on the basis of a distance in which the current sheet is fed by the separation conveying portion, the contact operation to feed the subsequent sheet.

First claim

1 . A sheet feeding device comprising:
a stacking portion configured to stack a sheet; a feeding portion configured to feed the sheet stacked on said stacking portion in a feeding direction in contact with an upper surface of the sheet; a contact and separation mechanism configured to move said feeding portion toward and away from the sheet stacked on said stacking portion; a separation conveying portion configured to convey the sheet fed by said feeding portion while separating the sheet one by one in a separating portion positioned downstream of said feeding portion with respect to the feeding direction; a detecting portion configured to detect the sheet on a side downstream of said separating portion with respect to the feeding direction; a size acquiring portion configured to acquire information on a size of the sheet stacked on said stacking portion; and a controller configured to execute a separating operation in which after said controller causes said feeding portion to start feeding of a current sheet in a state in which said feeding portion contacts the current sheet stacked on said stacking portion, said controller causes said contact and separation mechanism to move said feeding portion away from the sheet stacked on said stacking portion, wherein on the basis of the information acquired by said size acquiring portion, said controller executes either one of operations in a plurality of modes including a first mode and a second mode, wherein in said first mode, in a case that said detecting portion detects passing of the trailing end of the current sheet after execution of said separating operation, said controller causes said contact and separation mechanism to start a contact operation in which said feeding portion is contacted to the sheet stacked on said stacking portion by said contact and separation mechanism to feed a subsequent sheet, and wherein in the second mode, before said detecting portion detects the passing of the trailing end of the current sheet after the execution of said separating operation, said controller causes said contact and separation mechanism to start, on the basis of a distance in which the current sheet is fed by said separation conveying portion, the contact operation to feed the subsequent sheet.

2 . A sheet feeding device according to claim 1 , wherein said size acquiring portion includes a sheet width detecting portion provided to said stacking portion and configured to detect a sheet width with respect to a widthwise direction perpendicular to said feeding direction, and
wherein said controller executes the operation in said first mode when the sheet width detected by said sheet width detecting portion is smaller than a predetermined threshold, and executes the operation in said second mode when the sheet width detected by said sheet width detecting portion is the threshold or more.

3 . A sheet feeding device according to claim 2 , further comprising a side end restricting portion provided on said stacking portion so as to be movable in the widthwise direction and configured to restrict a position, with respect to the widthwise direction, of the sheet stacked on said stacking portion.

4 . A sheet feeding device according to claim 1 , wherein said controller executes the operation in the first mode when the information acquired by said size acquiring portion indicates that a size of the sheet stacked on the stacking portion does not correspond to any one of a plurality of preset sizes, and executes the operation in the second mode when the information acquired by said size acquiring portion indicates that the size of the sheet stacked on the stacking portion corresponds to any one of the plurality of preset sizes.

5 . A sheet feeding device according to claim 1 , wherein said controller is configured to start the contact operation in a case that the distance in which the current sheet is fed by said separation conveying portion from a time when said detecting portion detects a leading end of the current sheet is not less than a predetermined distance, and
wherein the predetermined distance is set at a length which is not less than a movement distance of the current sheet from passing of the leading end of the current sheet through a detecting position of said detecting portion until a trailing end of the current sheet passes through a position where the feeding portion contacts the sheet stacked on the stacking portion in a case that the contact operation is performed.

6 . A sheet feeding device according to claim 5 , wherein said size acquiring portion includes a sheet length detecting portion provided to said stacking portion and configured to detect information on a length, with respect to the feeding direction, of the sheet stacked on the stacking portion, and
wherein a value of the predetermined distance is changed depending on a detection result of said sheet length detecting portion.

7 . A sheet feeding device according to claim 1 , further comprising:
a first driving source configured to drive said feeding portion and to feed the sheet; and a second driving source configured to drive said contact and separation mechanism and to cause said contact and separation mechanism to perform the contact operation and the separating operation, wherein in a case that in the operation in the second mode, the contact operation is executed by causing said second driving source to drive said contact and separation mechanism before said detecting portion detects passing of a trailing end of the current sheet, drive of said feeding portion by said first driving source is started after said feeding portion is on standby until said detecting portion detects the passing of the trailing end of the current sheet.

8 . A sheet feeding device according to claim 7 , further comprising:
a downstream conveying portion configured to convey the sheet on a side downstream of said separation conveying portion with respect to the feeding direction; a third driving source configured to drive said downstream conveying portion; and a downstream detecting portion configured to detect the sheet on a side downstream of said downstream conveying portion, wherein said first driving source is configured to drive said separation conveying portion, and wherein after said controller causes said feeding portion to feed the current sheet, on the basis of detection of the leading end of the current sheet by said detecting portion, said controller causes said second driving source to drive said contact and separation mechanism and thus causes said contact and separation mechanism to execute the separating operation, and thereafter said controller causes said first driving source to stop the drive of said feeding portion on the basis of detection of the leading end of the current sheet by said downstream detecting portion.

9 . A sheet feeding device according to claim 1 , wherein said feeding portion is a feeding roller supported by a swingable member which is swingable upward and downward,
wherein said contact and separation mechanism is configured to move said feeding roller relative to said stacking portion by swinging said swingable member, and wherein said separation conveying portion includes a conveying roller configured to convey the sheet in the feeding direction and a separating portion configured to form said separating portion between itself and said conveying roller and configured to separate the sheet by imparting a frictional force to the sheet passing through said separating portion.

10 . An image reading apparatus comprising:
a sheet feeding device according to claim 1 ; and a reading portion configured to read an image on a sheet fed by said sheet feeding device.

Assignees

• Canon Kk

Inventors

• Suga Takayuki

Classifications

• B65H3/0684

  on moving support, e.g. pivoting, for bringing the roller or like rotary separator into contact with the pile · CPC title

• B65H2511/10

  Size; Dimensions · CPC title

• B65H7/02

  by feelers or detectors · CPC title

• B65H2513/50

  Timing · CPC title

• B65H2511/414

  of mode of operation · CPC title