Device for reading and/or writing information from/onto an optical information carrier

A device for reading and recording information on an optical information carrier, said information carrier having information stored therewithin as patterns formed by differences in intensity levels, said device comprising:

• a read system adapted to read data from said optical information carrier, said read system further comprising a radiation beam source, a radiation beam, a device for focusing said radiation beam, a scanning spot formed with said focused radiation beam and proximate said optical information carrier, said scanning spot having an intensity, a motion control device for controlling movement of said scanning spot relative to said optical information carrier, and for generating a read signal which is indicative of the intensity of the radiation reflected from the information carrier at the location of the scanning spot, said read system further adapted to derive, from said optical information carrier via said scanning spot, a measurement signal, a radial error signal, and an information signal;
• and
• a signal generation system operatively coupled to said read system, said signal generation system adapted to produce a sample signal to control sampling of said measurement signal, said sample signal proportional to the intensity of said scanning spot, and wherein said sample signal causes the measurement signal to be sampled at locations having mutually the same intensity level and wherein said sample signal causes the measurement signal to be sampled if the measurement signal has not been sampled within a predetermined time interval.

A method of reading information stored on an optical information carrier, said method comprising:

• providing an optical information carrier, said optical information carrier having a multilevel structure, and said optical information carrier bearing data recorded as patterns formed in the information carrier by differences in intensity levels;
• providing a read system adapted to read data from said optical information carrier, said read system further comprising a radiation beam source, a radiation beam, a device for focusing said radiation beam, a scanning spot formed with said focused radiation beam and proximate said optical information carrier, said scanning spot having an intensity, a motion control device for controlling movement of said scanning spot relative to said optical information carrier, and for generating a read signal which is indicative of the intensity of the radiation reflected from the information carrier at the location of the scanning spot, said read system further adapted to derive, from said optical information carrier via said scanning spot, a measurement signal, a radial error signal, and an information signal;
• and
• providing a signal generation system operatively coupled to said read system, said signal generation system adapted to produce a sample signal to control sampling of said measurement signal, said sample signal proportional to the intensity of said scanning spot, and wherein said sample signal causes the measurement signal to be sampled at locations having mutually the same intensity level and if the measurement signal has not been sampled to cause sampling of the measurement single within a predetermined time period.

An apparatus for employing an optical information carrier, said apparatus comprising:

• device for reading and recording information on said optical information carrier, said information carrier having information stored therewithin as patterns formed by differences in levels;
• a read system adapted to read data from said optical information carrier, said read system further comprising a radiation beam source, a radiation beam, a device for focusing said radiation beam, a scanning spot formed with said focused radiation beam and proximate said optical information carrier, said scanning spot having an intensity, a motion control device for controlling movement of said scanning spot relative to said optical information carrier, and a device for deriving, from said optical information carrier via said scanning spot, a measurement signal, a radial error signal, and an information signal;
• and
• a signal generation system operatively coupled to said read system, said signal generation system adapted to produce a sample signal to control sampling of said measurement signal, said sample signal proportional to the intensity of said scanning spot, and wherein said sample signal causes the measurement signal to be sampled when said intensity is comparatively high and wherein if the measurement signal is not sampled within a predetermined time period then said sample signal causes the measurement signal to be sampled.