US 11,807,489 B2
Medium conveying apparatus to change determination threshold for multi-feed of medium according to size of overlap area in medium
Masaaki Sakai, Kahoku (JP)
Assigned to PFU LIMITED, Kahoku (JP)
Filed by PFU LIMITED, Kahoku (JP)
Filed on Jan. 18, 2022, as Appl. No. 17/578,101.
Claims priority of application No. 2021-024578 (JP), filed on Feb. 18, 2021.
Prior Publication US 2022/0258996 A1, Aug. 18, 2022
Int. Cl. B65H 7/12 (2006.01); B65H 7/18 (2006.01)
CPC B65H 7/125 (2013.01) [B65H 7/18 (2013.01); B65H 2511/416 (2013.01); B65H 2511/524 (2013.01); B65H 2553/30 (2013.01); B65H 2557/63 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A medium conveying apparatus comprising:
a conveying roller to convey a medium; and
a processor to
detect transmission information of an ultrasonic wave transmitted through the medium or thickness information of the medium at a plurality of positions in the conveyed medium,
calculate a size of an area in which the transmission information or the thickness information is within a predetermined range in the conveyed medium,
determine whether a multi-feed of the medium has occurred, by comparing a value based on the transmission information or the thickness information with a threshold, and
execute an abnormality processing when it is determined that the multi-feed of the medium has occurred, wherein
the processor changes the threshold according to the size.