Shutter member for a magnetic disk cartridge

Claim 1

A magnetic disk cartridge comprising a magnetic disk for conducting image recording and reproducing through high-speed rotation, said disk including a flexible, disk-like recording medium having a central portion, and a hub at said central portion, said cartridge also comprising an approximately square sheet-like case having upper and lower halves for containing said magnetic disk therebetween, one of said halves having a magnetic head receiving hole for insertion of a magnetic head for image recording and reproducing and being located in the vicinity of a diagonal line of said case, wherein the improvement comprises a unitary shutter member rotatably mounted within said case between said halves, said shutter member including a main body portion which is generally rectangular and has a rotation center at a corner portion of said case nearest to said magnetic head receiving hole, said shutter member also including a smaller rectangular arm defining a protrusion extending outwardly from the main body portion at an obtuse angle therefrom so that a corner of that arm projects out of the case to a position for engagement with an exterior shutter opening contact member of a recording device when inserted therein whereby said shutter member will rotate to open said magnetic head receiving hole.