Magnetic tape cartridge

A magnetic tape cartridge comprising a cartridge casing, a single reel around which a magnetic tape is wound and which is contained in the cartridge casing for rotation, a slide door for opening and closing a tape outlet opening mounted on the cartridge casing to be linearly slidable between a closing position where it closes the tape outlet opening and an opening position where it opens the tape outlet opening, and a door spring for urging the slide door toward the closing position and holding the same in the closing position is disposed on the door passage,

• wherein a flexible engagement member is brought into engagement with the cartridge casing in response to return of the slide door to the closing position under the urging force of the door spring and locks the slide door in the closing position is provided on the slide door so that the engagement member is deflected in a direction in which the engagement member is disengaged from the cartridge casing when a force pushing the slide door toward the opening position is applied to the engagement member.

A magnetic tape cartridge comprising a cartridge casing, a single reel around which a magnetic tape is wound and which is contained in the cartridge casing for rotation, and a slide door for opening and closing a tape outlet opening mounted on the cartridge casing to be linearly slidable along a door passage,

• wherein an outer surface of the slide door has at least one cutout which engages an inside surface of the casing when the tape outlet opening is closed, thereby positioning an end face of the outer surface of the slide door inside the outer surface of the cartridge opening.