US 11,905,137 B2
Sheet feeding device and image forming apparatus
Yuma Inui, Ibaraki (JP)
Assigned to Canon Kabushiki Kaisha, Tokyo (JP)
Filed by CANON KABUSHIKI KAISHA, Tokyo (JP)
Filed on Aug. 20, 2021, as Appl. No. 17/407,286.
Claims priority of application No. 2020-148277 (JP), filed on Sep. 3, 2020; and application No. 2021-126405 (JP), filed on Aug. 2, 2021.
Prior Publication US 2022/0063943 A1, Mar. 3, 2022
Int. Cl. B65H 5/06 (2006.01); B65H 7/02 (2006.01)
CPC B65H 5/062 (2013.01) [B65H 7/02 (2013.01); B65H 2511/11 (2013.01); B65H 2513/10 (2013.01); B65H 2513/50 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A sheet feeding device comprising:
a first feeding roller pair rotatable in a sheet nipping state and configured to feed a sheet;
an upstream feeding roller pair provided upstream of said first feeding roller pair with respect to a sheet feeding direction and configured to feed the sheet;
a downstream feeding roller pair provided downstream of said first feeding roller pair with respect to the sheet feeding direction and configured to feed the sheet;
a second feeding roller pair provided downstream of said downstream feeding roller pair with respect to the sheet feeding direction and configured to feed the sheet;
a first detecting portion provided at a first detecting position downstream of said first feeding roller pair and upstream of said downstream feeding roller pair with respect to the sheet feeding direction and configured to detect passing of a leading end portion of the sheet fed by said first feeding roller pair;
a second detecting portion provided at a second detecting position, different from the first detecting position, downstream of said first feeding roller pair and upstream of said downstream feeding roller pair with respect to the sheet feeding direction and configured to detect the passing of the leading end portion of the sheet fed by said first feeding roller pair;
a third detecting portion provided at a third detecting position upstream of said first feeding roller pair and downstream of said upstream feeding roller pair with respect to the sheet feeding direction and configured to detect passing of a trailing end portion of the sheet fed by said first feeding roller pair; and
a controller configured to perform calculation in response to signals from said first detecting portion, said second detecting portion, and said third detecting portion,
wherein said controller calculates a sheet feeding speed on the basis of a first time which is a difference between a timing when the leading end portion of the sheet passes through the first detecting position and a timing when the leading end portion of the sheet passes through the second detecting position and a first distance between the first detecting position and the second detecting position with respect to the sheet feeding direction,
wherein said controller calculates a length of the sheet with respect to the sheet feeding direction on the basis of the sheet feeding speed, a second time which is a difference between a timing when the leading end portion of the sheet passes through the second detecting position and a timing when the trailing end portion of the sheet passes through the third detecting position, and a second distance between the second detecting position and the third detecting position with respect to the sheet feeding direction, and
wherein said controller controls a sheet feeding timing by said second feeding roller pair on the basis of information of the length of the sheet.