| 摘要 |
PROBLEM TO BE SOLVED: To reduce error correction probability and to improve recording densi ty by recording a block unit adding a parity of a prescribed number to each row, each column of digital information over plural sectors and making it a product code, and performing prescribed processing at a demodulating time. SOLUTION: The parity of the prescribed number of symbols are added to the symbol data arranged in the row direction and column direction by a modulation circuit 14 to be made the product code, and the whole is made one block, and an address is added to be recorded on a recording medium 1 through an optical head 10. At the demodulating time, a data control circuit 15 reads the signal of the specified block, and stores it temporarily in a buffer memory 16, and an error correction circuit 17 performs error correction processing in the row direction and column direction. The correction in the row direction and column direction are repeated alternately till the correction is furnished. Thus, since a burst error is eliminated, and the protection layer of the recording medium is thinned, a numerical aperture of an objective lens 11 is enlarged, and the recording density is improved. |
