Magnetic tape cassette

摘要

At both sides of an opening (14) of a cassette case (10a), there are formed tape guides (18) having guide faces (18a), and a magnetic tape (T) is stretched between the guide faces (18a). On back faces (18b) of the guide faces (18a) of the tape guides (18), are formed cam grooves (26) for guiding an open/close lid (320) which covers the stretched magnetic tape (T). In lower parts of the back faces (18b) and backward of the cam grooves (26), there are formed projections (28) provided with position detecting holes (28a). Molding sink preventive recesses are formed only at positions on the back faces (18b) forward of the cam grooves (26) and above the projections (28).