| 摘要 |
PURPOSE:To attain sure opening/closing of a head window in interlocking with the loading/ejecting of a disc with simple structure by providing a disc form shutter having an opening part to a position corresponding to a center of a tooth part of a circumferential part. CONSTITUTION:Tooth parts 1-3 are formed to the circumferential part of the shutter 8 formed as a disc made of a synthetic resin at an equal angular interval and within a fixed angular range. Then opening parts 4-6 are formed to a position corresponding to the center of the tooth parts 1-3. The two shutters 8 of the structure as above are prepared and the shutters 8 are arranged (one each at the upper and lower part) in a magnetic disc cassette while clipping a magnetic disc. A center hole 9 and a head window 10 are formed to a magnetic disc cassette 15. Further, projections 13, 14 are provided projectingly in the magnetic disc cassette 15 and one of the projections 13, 14 is provided to be meshed with one of the tooth parts 1-3 of the shutter 8 without fail at all times. In loading the cassette 15 in the magnetic disc device, the shutter 8 is turned while being engaged with one of the tooth part 1-3 and the head window 10 is opened. |
