| 摘要 |
PURPOSE:To attain automatically the reproduction at a suitable rotating speed of a disc by discriminating a reproduced output at reproduction and switching the servo condition so that the correct reproducing speed of the disc is obtained by the discrimination output. CONSTITUTION:An optical pickup system 3 has a laser light source, a lens system and a photodetector and scans the recording part of a range (d) of the disc 1 radially from the inner to the outer circumference. The disc 1 is rotated by a rotating mechanism system 4, in which a servo circuit 5 is employed and the rotating speed of the disc 1 is set by the circuit 5. When the disc 1 is loaded to the reproducer and the reproducer is started, a minimum speed setting circuit 7 is activated by a controller 6, its output is applied to a rotating condition switching circuit 8, and the rotating mechanism system 4 is set to a speed where the speed information is recorded to the recording part 2 of the disc 1 independently of the substantial reproducing speed of the disc by the servo circuit 5. |
