Method and apparatus for recording and reproducing information on and from optical disc
View Patent ↗An apparatus for recording and reproducing an information signal on and from an optical disc includes a memory. The information signal is written into the memory. The information signal is read out from the memory. An optical head generates a laser beam in response to the readout information signal, and applies the laser beam to the optical disc to record the readout information signal on the optical disc. A test signal is recorded on a position of the optical disc near a recording position thereof via the optical head during the writing of the information signal into the memory. The test signal is reproduced from the optical disc. The reproduced test signal is evaluated to generate an evaluation result. An intensity of the laser beam is optimized in response to the evaluation result.
1. A method of optically recording information on an optical disc including first and second recording layers, the method comprising the steps of:
performing a focus jump between the first and second recording layers;
repetitively generating a random signal as a test signal;
shifting a timing of at least one pulse in the repetitively generated random signal;
optically recording the repetitively generated random signal on the first recording layer to perform test recording with respect to the first recording layer while the timing of at least one pulse in the repetitively generated random signal is shifted;
reproducing the recorded random signal from the first recording layer;
evaluating the random signal reproduced from the first recording layer to obtain a first evaluation result;
deciding an optimal recording power for recording with respect to the first recording layer on the basis of said obtained first evaluation result;
optically recording the repetitively generated random signal on the second recording layer to perform test recording with respect to the second recording layer while the timing of at least one pulse in the repetitively generated random signal is shifted;
reproducing the recorded random signal from the second recording layer;
evaluating the random signal reproduced from the second recording layer to obtain a second evaluation result;
deciding an optimal recording power for recording with respect to the second recording layer on the basis of said obtained second evaluation result;
optically recording information on the first recording layer;
optically recording information on the second recording layer; and
recording, on a management area of the first recording layer, information for identifying an apparatus which made the information recording.
2. A method of reproducing information from an optical disc on which the information has been recorded by the method of claim 1 , comprising the steps of:
moving an optical pickup along tracks on the first and second recording layers;
making the optical pickup perform a focus jump between the first and second recording layers;
locating the optical pickup with respect to the track on the first or second recording layer; and
optically reproducing information from the track on the first or second recording layer which the optical pickup is located with respect to.
3. An apparatus for optically recording information on an optical disc including first and second recording layers, the apparatus comprising:
means for performing a focus jump between the first and second recording layers;
means for repetitively generating a random signal as a test signal;
means for shifting a timing of at least one pulse in the repetitively generated random signal;
means for optically recording the repetitively generated random signal on the first recording layer to perform test recording with respect to the first recording layer while the timing of at least one pulse in the repetitively generated random signal is shifted;
means for reproducing the recorded random signal from the first recording layer;
means for evaluating the random signal reproduced from the first recording layer to obtain a first evaluation result;
means for deciding an optimal recording power for recording with respect to the first recording layer on the basis of said obtained first evaluation result;
means for optically recording the repetitively generated random signal on the second recording layer to perform test recording with respect to the second recording layer while the timing of at least one pulse in the repetitively generated random signal is shifted;
means for reproducing the recorded random signal from the second recording layer;
means for evaluating the random signal reproduced from the second recording layer to obtain a second evaluation result;
means for deciding an optimal recording power for recording with respect to the second recording layer on the basis of said obtained second evaluation result;
means for optically recording information on the first recording layer;
means for optically recording information on the second recording layer; and
means for recording, on a management area of the first recording layer, information for identifying an apparatus which made the information recording.
4. An apparatus for reproducing information from an optical disc on which the information has been recorded by the apparatus of claim 3 , comprising:
means for moving an optical pickup along tracks on the first and second recording layers;
means for making the optical pickup perform a focus jump between the first and second recording layers;
means for locating the optical pickup with respect to the track on the first or second recording layer; and
means for optically reproducing information from the track on the first or second recording layer which the optical pickup is located with respect to.