| 摘要 |
PURPOSE:To prevent recording content breakdown of media through mis-operation by providing a mechanism which is capable of transmitting the states of ''write inhibit'' and ''write permit'' to the magnetic disc apparatus to the disc medium and detecting this with the disc apparatus. CONSTITUTION:When the write protection display switch 1 provided on the surface of a magnetic disc medium is set to the write permit side, the reflecting mirror 2 provided to the bottom guide of the magnetic disc medium moves in the operating direction of the switch 1 and the quantity of reflected light from the lamp 6 thereunder is sensed by a photo detector 7. When the switch 1 is on the write inhibit side, light falls to the portion of high reflectance of the reflecting plate 2 and the state ''1'' is indicated via the detector 7. When it is on the permit side, the state opposite from the above is set, thus indicating ''0''. when this signal having passed through a control part 17 and the signal from the switch 19 of a display plate 18 are logically added in an OR circuit, the write inhibit is set. Hence, if the switch 1 is on the write inhibit side even if the switch 19 is on the write permit side, the writing to the medium is inhibited. Thereby, recording content breakdown of the medium may be prevented. |
