| 摘要 |
PURPOSE:To make it possible to select freely a track positioning information pattern by making constant the readout time of the servo signal area of a sector servo system and then by locking the system until the next servo signal area the time later. CONSTITUTION:On detection of servo signal areas 14a and 14b, sample gate circuit 44 is driven at input timing to permit a servo signal inputted from terminal 40 to pass through it only for time T and after time T passes, sample gate circuit 44 is closed to develop the current charged voltage of capacitor 46 at output terminal 47, thereby holding the next servo signal area in a constant state. In this case, two-bit, three-bit systems, etc., can be selectively used for the servo signal. |
