| 摘要 |
PURPOSE:To attain quick search, by shifting a pickup by a distance based on a distance data between the radius of the present position and that of the objective position of the pickup, in the reproduction of the disc on which a digital data is recorded. CONSTITUTION:The radius of the disc 140 of the position from the absolute address of the present position of the pickup 142 is calculated, the radius of the disc 140 of the position from the absolute address of the objective position is calculated, and the distance to shift the pickup is decided by obtaining the difference of the both (distance data). The number of pulse of a position detecting signal geneating one pulse every time the pickup is shifted and the spot crosses over one track, is counted, and when the shift distance of the pickup is equal to the said distance data, the pickup is stopped. In this case, the position detecting signal of the pickup 142 is produced by using the level change of the electric signal generated when the spot crosses actually over the track. |
