Optical information recording and reproducing apparatus having defective-sector marking means

摘要

An optical information recording and reproducing apparatus for recording and reproducing information from an optical recording disc including an optically detectable guide track preliminarily divided into a plurality of sectors. In the case of an unerasable disc, if an uncorrectable error exists in any sector after data has been recorded and reproduced from the sector, it is necessary to process this sector so as to prevent further reproduction an again record the data in another sector. Also, when updating a part of the data or erasing the file, it is desirable to take a measure so that reproduction of the data in any unwanted sector is prevented. Also, in the case of any unrecorded sector involving such dropout that the recording of data is presumed to cause an uncorrectable error, it is desirable to handle it as a defective sector and process it so as to prevent the recording of data therein. In such a case, it is desirable to effect the similar process also in the case of an erasable disc. A conceivable method of making such defective or unwanted sector distinguishable at a later time is to write in its information recording area a signal having a special pattern indicative of the defective or unwanted sector. In accordance with the invention, the reliability of special signal detection is increased by writing the special signal again when it is impossible to detect the special signal due to the occurrence of a track jump prior to or during the writing of the special signal, due to the occurrence of dropouts or the like.