Information recording medium cartridge

An information recording medium cartridge provide with a disc-like information recording medium, a cartridge casing having the information recording medium accommodated therein, a shutter slidably mounted to the cartridge casing and for opening and closing recording and/or reproducing openings arranged in right and reverse sides of the cartridge casing, and a slide member for movably mounting the shutter to the cartridge casing in a direction to open and close the openings,

• wherein the shutter is provided with a first shutter plate for opening and closing the recording and/or reproducing opening arranged in one of the right and reverse sides of the cartridge casing and a second shutter plate for opening and closing the recording and/or reproducing opening arranged in another side of the cartridge casing,
• wherein the first and second shutter plates are independently moved between a first position for closing the recording and/or reproducing openings arranged in the right and reverse sides of the cartridge casing and a second position for opening the recording and/or reproducing openings, characterized in that
• the first and second shutter plates are of a size enough large to close the recording and/or reproducing openings arranged in the right and reverse sides of the cartridge casing and substantially the same width as that of the openings, and that in the first position for closing the recording and/or reproducing openings, the first and second shutter plates are formed to overlap one another in a vertical direction of the cartridge casing.