Patent ID: 7077352
Filing Date: 2006-07-18
Classification: G11B

Abstract:
1. A magnetic tape cartridge comprising: a single reel with magnetic tape wound thereon; a cartridge case in which said reel is rotatably housed, said reel including through holes and one or more vertical ribs; and reel-rotation restraining means which allows rotation of said reel during use and restricts said rotation during periods of nonuse; wherein said reel-rotation restraining means comprises: a reel locking member, which is movable toward and away from said reel, for restricting rotation of said reel, an urging member for urging said reel locking member in a restraining direction, and a releasing member, which is rotatable integrally with said reel, for moving said reel locking member in an unlocking direction by moving according to a chucking operation of rotation means provided in a drive unit; and wherein said releasing member comprises: a generally triangular plate portion, and three leg portions, provided on vertexes of said triangular plate portion, at least one of the three leg portions abutting against at least one of the vertical ribs acting as an alignment guide, and each leg portion having a lower end which is inserted into one of the through holes provided in said reel and abuts part of the rotation means of said drive unit; and wherein a size of a center opening of the reel is smaller than that of a portion of the cartridge case in which the releasing member is housed.