Spool, long member, conveying device, and cleaning device

A spool that is rotatably journaled and has a long member wound around the spool, the spool comprising:

• a marker with which a side face of the spool is provided, the side face being orthogonal to a rotation axis of the spool,
• wherein:
• the marker includes an information-detection bit marker indicating information regarding the long member,
• the information-detection bit marker is disposed equidistant from the rotation axis,
• in a case where a circle about the rotation axis is circumferentially divided into N (N≥2) number of divided regions that are fan-shaped, (i) the information-detection bit marker is disposed in at least one of the N number of divided regions, and (ii) the information binary-encoded is indicated based on presence or absence of the information-detection bit marker for each of the N number of divided regions,
• the marker includes N number of information-detection point markers in total,
• the N number of information-detection point markers are disposed one-to-one in the N number of divided regions, spaced apart from each other, equidistant from the rotation axis, and different in distance from the rotation axis from the information-detection bit marker,
• the information-detection bit marker is identical in orientation based on the rotation axis to the N number of information detection point markers, and
• the marker includes an information start-point marker that is identical in distance from the rotation axis to the information-detection bit marker and is identical in orientation based on the rotation axis to a region interposed between two information-detection point markers circumferentially adjacent to each other among the N number of information-detection point markers.