| 摘要 |
<p>PURPOSE:To make the tracking speed of a tracking device higher and stable at the time of variable-speed reproduction and, at the same time, to stabilize the tracking speed even when the device is provided with a guide band by providing a means which detects a tracking error from the difference between pilot signals of both adjacent tracks of a main track. CONSTITUTION:Reproduced signals inputted from an input terminal 41 are inputted to a pilot detector 4 through preamplifier 1, LPF 2, and AGC 3 and each component of pilot signals is extracted. Then the difference between the pilot signals selected by means of switches 5 and 6 is taken through envelope detection circuits 7 and 8 and a subtracter 9. A switch 18 selects the difference signal at the time of normal reproduction and the integrated result of the difference signal at the time of variable-reproduction and outputs the selected signals as a tracking error signal from a terminal 42. In other words, tracking control is performed by using the difference between the pilot signals of both adjacent tracks when reproduction is made in a variable-reproduction mode and a main track when reproduction is made in an SP mode. Therefore, high-speed, stable, and high-performance tracking control can be realized without deteriorating the S/N.</p> |
