Optical disk device

Abstract

Abstract PURPOSE:To assure high reliability of a disk without destruction of data on a disk even under an abnormal condition, by detecting an abnormal condition in the number revolution of the disk and stopping or lowering a recording light in accordance with the detect signal. CONSTITUTION:The number of revolution of a motor 11 for rotating a disk 12 is detected by a motor driving circuit 13 and the output 1 of the circuit 13 and the output 2 of a reference output generating circuit 10 are inputted into a number of revolution comparing circuit 3. The circuit 3 compares whether the number of revolution of the disk 12 is in an allowable variation range or not and, when the number of revolution is out of the range, a rotation normal signal 4 becomes false and the signal is inputted into a laser output controlling circuit 6 together with a laser output ''on'' signal 5, a laser driving circuit 8 does not work even when the laser output ''on'' signal 5 is real and a laser diode 9 does not emit lights. Therefore, data on the disk 12 are not destructed even under an abnormal condition and a high reliability can be guaranteed to the disk 12.

Inventors

• 👤 Yasumitsu Mizoguchi
• 👤 溝口　康充
• 👤 Masahiro Takasago
• 👤 高砂　昌弘
• 👤 Hiromi Senoo
• 👤 妹尾　広美

Bibliographic Details