Patent ID: 8559135

Claim:
A magnetic tape reel that has a plurality of gear teeth capable of engaging with a plurality of engagement gear teeth provided with a reel engaging portion of a recording and reproducing apparatus and upon which magnetic tape can be wound, the reel comprising: a hub portion including a cylindrical portion upon which the magnetic tape can be wound and the plurality of gear teeth; and a positioning mark capable of being detected using a contactless detector, the positioning mark being provided for aligning a specific gear tooth A from the plurality of gear teeth with a specific engagement gear tooth B from the plurality of engagement gear teeth, wherein the hub portion has a closed-end cylindrical shape, and the plurality of gear teeth are provided on an external surface of a base portion of the hub portion having a closed-end cylindrical shape, the magnetic tape reel further comprising: a first flange extending in a radial direction from a peripheral surface of one end of the hub portion; and a second flange extending in a radial direction from a peripheral surface of the other end of the hub portion that is closer to the base portion than the one end, wherein the positioning mark is provided on the external surface of the base portion of the hub portion, and the positioning mark is detected by a detection portion that is provided on the reel engaging portion of the recording and reproducing apparatus.