Patent ID: 7011263

Claim:
A recording tape cartridge comprising: a case which is substantially rectangular, and which rotatably accommodates a single reel on which a recording tape is wound; a portion having an opening formed at a corner portion of the case at a side of loading the case into a drive device, the opening being for pulling-out of a leader member attached to an end portion of the recording tape; a shielding member sliding so as to open and close the opening; and a dustproofing wall formed at a peripheral edge portion of the opening, and when the shielding member closes the opening, the dustproofing wall overlaps with the full width of a distal end of the shielding member so that the distal end of the shielding member is positioned at the inner side of the dustproofing wall; wherein said corner portion is provided between peripheral walls of the case, and said corner portion is cut obliquely with respect to said peripheral walls; wherein the shielding member is a door which is arc-shaped in plan view, and which curves along a direction of a thickness of the shielding member so as to be movable along a given circumference.