| 摘要 |
PURPOSE:To attain both sides recording and to prolong the life of a disc with a simple constitution by arranging the 1st index detector corresponding the position to an index detecting window of the disc and detecting the index at the reverse setting of the disc by the 2nd index detector. CONSTITUTION:When the disc is set up on reversely a magnetic disc device, the index detecting window 22 is opposed to the 2nd index detector 100 and a record protecting notched part 23 is opposed to the 2nd record protecting part detector 110. Therefore, an index detecting signal is generated from the 2nd index detector 100 and sent to a computer. The opening/closing status of the notched part 22 is detected by the 2nd record protecting part detector 110 and the detecting signal is sent to the computer. At that time, a side detector 12 does not detect a side detector 26, so that the detected output SS is in an ''L'' level and an AND circuit in an interface circuit is closed. Therefore, noise from the 1st record protecting part detector 11 is not fed to the computer. |
