CPC B41J 13/076 (2013.01) [B41J 2/01 (2013.01); B41J 11/0045 (2013.01); B41J 11/04 (2013.01); B65H 5/066 (2013.01); B65H 5/068 (2013.01); B65H 29/20 (2013.01)] | 10 Claims |
1. A roller that transports a medium, the roller comprising:
a wheel having a plurality of teeth on a peripheral surface; and
holders that hold n wheels, which satisfy condition 1 and condition 2, such that the n wheels are stacked in an axial direction, n being a natural number of 2 or more,
Pr=Pt/n, wherein condition 1:
Pr is a tooth pitch of the roller, and Pt is a tooth pitch of the wheel, and
condition 2: a minimum value of sums of angles each formed by a reference tooth and another reference tooth adjacent to the reference tooth in a circumferential direction of one to n wheels is greater than 180 degrees, wherein
one of the plurality of teeth is a reference tooth, and one of the n wheels is a reference wheel,
a wheel having a reference tooth nearest to the reference tooth of the reference wheel in the circumferential direction when viewed in a rotational axis direction of the wheel is a second wheel, and
wheels having reference teeth near to the reference tooth of the reference wheel in a direction identical to a direction in which the reference tooth of the second wheel is positioned with respect to the reference tooth of the reference wheel are second to nth wheels sequentially.
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