| 摘要 |
In an optical disc apparatus using an optical disc which has a number of sectors for recording coded information therein, a sector mark formed of a special pattern is previously recorded in each sector at the starting position thereof, to correctly read-out information recorded in each sector. In the case where the optical disc is normally operated, a normal sector mark signal corresponding to each sector mark is detected at a fixed time interval. However, the normal sector mark signal may not be detected for some reasons. A circuit is herein disclosed which generates a pseudo sector mark signal synchronized with the normal sector mark signal. When the normal sector mark signal is not detected, the psuedo sector mark signal is generated, and information recorded in a sector is appropriately processed on the basis of the pseudo sector mark signal. Further, this circuit is provided with circuit means for inhibiting the normal sector mark signal and psuedo sector mark signal from being delivered when the pseudo sector mark signal has been generated a predetermined number of times continuously. However, such inhibition is released when the repetition period of the normal sector mark signal is judged to lie within a predetermined range. |
