in reproducing an optical disc , the disc is reproduced first using a semiconductor laser of 770 - 800 nm in wavelength for cd , and if a correct data signal is obtained , the optical disc is identified as a cd , while if a correct data signal is not obtained , the optical disc is identified as a high - density optical disc and is reproduced using a semiconductor laser for high - density optical disc . according to this construction there can be provided an optical disc player capable of discriminating between different types of optical discs and reproducing the discs with semiconductor lasers respectively suitable for the discs . since a cd and a write - once type optical disc compatible with the cd are sure to be reproduced by a semiconductor laser of 770 - 800 nm for cd , it is impossible that there will occur breakdown of a recording layer of the write - once disc .