Tape cassette and magnetic recording/reproducing device.

摘要

A tape cassette comprising an inserting opening disposed in a main body case and a detecting optical path, for detecting the leading and rear ends of a tape, interposed between the inserting opening and an optical path window formed in the left and right side walls of the case, wherein the first distinguishing member is rotatably inserted into an upper portion of the inserting opening, is supported to be vertically slidable, and a mechanism for holding the first distinguishing member in each state is disposed between the first distinguishing member and the main body case, thereby to allow a tape deck to have a simple internal construction even though the tape cassette is of a smaller size, and to provide a construction of the detecting opening preferable for detecting cassette information so that the tape cassette can be used in a compatible form. <IMAGE>