Analog/digital converter and information recording and reproducing apparatus

An information recording and reproducing apparatus comprising:

• an optical pickup for applying a light beam to a track on an optical recording medium, the optical pickup having a photodetector for detecting a light beam reflected from the optical recording medium;
• and
• a reproducing circuit for acquiring a reproduced signal from a signal representing the detected light beam from the photodetector;
• the reproducing circuit including an analog/digital converter;
• the analog/digital converter including
• a plurality of comparators for comparing a plurality of respective standard voltages with an analog input value for a magnitude thereof, the comparators being arranged depending on magnitudes of the standard voltages;
• a logic boundary detector for detecting a logic boundary point where output signals from the comparators change from one level to another level;
• and
• a plurality of majority circuits for being supplied with the output signals from the comparators and determining output signals based on a majority vote on the output signals from the comparators, the majority circuits having logic threshold values adjusted for respective input terminals thereof which are supplied with the output signals from the comparators.

An information recording and reproducing apparatus comprising:

• an optical pickup for applying a light beam to a track on an optical recording medium, the optical pickup having a photodetector for detecting a light beam reflected from the optical recording medium;
• and
• a wobble signal extracting circuit for acquiring a wobble signal from a signal representing the detected light beam from the photodetector;
• the wobble signal extracting circuit including an analog/digital converter;
• the analog/digital converter including
• a plurality of comparators for comparing a plurality of respective standard voltages with an analog input value for a magnitude thereof, the comparators being arranged depending on magnitudes of the standard voltages;
• a logic boundary detector for detecting a logic boundary point where output signals from the comparators change from one level to another level;
• and
• a plurality of majority circuits for being supplied with the output signals from the comparators and determining output signals based on a majority vote on the output signals from the comparators, the majority circuits having logic threshold values adjusted for respective input terminals thereof which are supplied with the output signals from the comparators.