Abstract: An information recording/reproducing apparatus which allows freer utilization of data compressed under different data compression schemes. When data recorded on a magneto-optical disc of an MD under the ATRAC compression scheme is converted into that of the ATRAC3 compression scheme and re-recorded on the magneto-optical disc, selector switches are changed over in a predetermined combination. The data recorded under the ATRAC compression scheme is read and demodulated by a signal processing unit. The demodulation data is decoded into linear PCM data by a data expansion decoder. The linear PCM data is converted into data of the ATRAC3 compression scheme by a data compression encoder. The resultant is modulated by the signal processing unit and re-recorded on the magneto-optical disc. Here, the track numbers of the data originally recorded under the ATRAC compression scheme are kept unchanged, and associated with the data which is converted and recorded under the ATRAC3 compression scheme.

Abstract: A pickup is moved in the radial direction of a partial CD-R, and the end position of a recorded area in the partial CD-R is detected based on a feature signal (on track signal) in the radial direction obtained during the movement. Information recorded in the recorded area is reproduced based on the detected end position, so that an accessing inability can be avoided, and the information in the recorded area can correctly be reproduced. Thus, information recorded in the partial CD-R can correctly be reproduced.

Abstract: An information recording/reproducing apparatus which allows freer utilization of data compressed under different data compression schemes. When data recorded on a magneto-optical disc of an MD under the ATRAC compression scheme is converted into that of the ATRAC3 compression scheme and re-recorded on the magneto-optical disc, selector switches are changed over in a predetermined combination. The data recorded under the ATRAC compression scheme is read and demodulated by a signal processing unit. The demodulation data is decoded into linear PCM data by a data expansion decoder. The linear PCM data is converted into data of the ATRAC3 compression scheme by a data compression encoder. The resultant is modulated by the signal processing unit and re-recorded on the magneto-optical disc. Here, the track numbers of the data originally recorded under the ATRAC compression scheme are kept unchanged, and associated with the data which is converted and recorded under the ATRAC3 compression scheme.

Abstract: A pickup is moved in the radial direction of a partial CD-R, and the end position of a recorded area in the partial CD-R is detected based on a feature signal (on track signal) in the radial direction obtained during the movement. Information recorded in the recorded area is reproduced based on the detected end position, so that an accessing inability can be avoided, and the information in the recorded area can correctly be reproduced. Thus, information recorded in the partial CD-R can correctly be reproduced.