| 摘要 |
PURPOSE:To ensure the faithful following of a track when a disk of high density is rotated at a high speed for an information recording/reproducing device, by detecting the tracking signals which are recorded at both sides of a track with the prescribed intervals by means of a reproducing means and then performing the tracking. CONSTITUTION:Tracking signals 3011, 3012... are recorded on a track 101 in addition to video signals 2011, 2012.... The tracking signal contains two parts like 3001 and 3002, and these parts are shifted by 1/2 track width from the center of the track. If a light beam is placed at the center position of the track, the output is equal to each other between the parts 3001 and 3002. While either one of these outputs is larger than the other when the light beam is deflected to either side. Thus a tracking error signal is obtained in response to the volume and direction of the light beam. Therefore it is required just to control the direction of the optical beam by means of the error signal and so that the error signal is set at 0. |
