Disk drive apparatus and information reading method

A method for reading out information recorded in lands and grooves on a recording medium, said method comprising:

• a step of generating tracking error signals indicating deviation of a scanning position of said readout means on said recording medium;
• a step of correcting said tracking error signals;
• a step of inverting the corrected tracking error signals to generate inverted tracking error signals;
• a step of detecting which of said land and said groove is scanned by said readout means;
• and
• a step of selecting one of said tracking error signals and said inverted tracking error signals, according to the results of detection, and of tracking-controlling said readout means by the selected signals.

A disc driving apparatus for reading out the information from a recording medium with lands and grooves, formed alternately in the radial direction thereon, by scanning said information recorded in said lands and grooves with readout means, said disc driving apparatus comprising:

• tracking error signal generating means for generating tracking error signals, indicating the deviation of the scanning position of said readout means;
• pulse signal generating means for generating pulse signals activated during the time said tracking error signals exceed a preset threshold value;
• and
• half-track jump controlling means for accelerating said readout means to move said readout means to an adjacent land or groove, and for accelerating the movement of said readout means in a negative direction when said pulse signals are activated to change the scanning position of said readout means to a desired adjacent land or groove.

A method for reading out information from a recording medium with lands and grooves, formed alternately in the radial direction thereon, by scanning said information recorded in said lands and grooves with readout means, said method comprising:

• a step of generating tracking error signals, indicating the deviation of the scanning position of said readout means;
• a step of generating pulse signals activated during the time said tracking error signals exceed a preset threshold value;
• a step of accelerating said readout means for moving said readout means to an adjacent land or groove;
• and
• a step of accelerating the movement of said readout means in a negative direction when said pulse signals are activated to change the scanning position of said readout means to a desired adjacent land or groove.

A disc driving apparatus for reading out the information from a recording medium with lands and grooves by readout means, said information being recorded in said lands and grooves, said apparatus comprising:

• focussing error signal generating means for generating focussing error signals controlling the distance of said readout means against said recording medium;
• storage means for storing, in advance, a first bias value determined according to the optimum distance when said readout means scans said land, and a second bias value determined according to said distance which is optimum when said readout means scans said groove;
• detection means for detecting which of the land and the groove is scanned by said readout means;
• correction means for selecting said first bias value or said second bias value, stored previously in said storage means, according to the results of detection by said detection means, and for correcting the supplied focussing error signals by the selected bias value;
• and
• driving means for driving said readout means according to the focussing error signals corrected by said correction means to control said distance.

A method for reading out information from a recording medium with lands and grooves by readout means, said information being recorded in said lands and grooves, said method comprising:

• a step of specifying, in advance, a first bias value determined according to an optimum distance between said readout means and said recording medium when said readout means scans said land, and a second bias value determined according to said distance, which is optimum when said readout means scans said groove;
• a step of generating focussing error signals controlling the distance between said readout means and the recording medium;
• a step of detecting which of the land and the groove said readout means is scanning;
• a step of selecting said first bias value or said second bias value, according to the results of detection, and of correcting said focussing error signals by the selected bias value;
• and
• a step of driving said readout means according to the corrected focussing error signals to control said distance.

A method for reading out the information from a recording medium with lands and grooves by readout means, said information being recorded in said lands and grooves, said method comprising:

• a step of specifying, in advance, a first bias value determined according to an optimum distance between the readout means and the recording medium when said readout means scans said land, and a second bias value determined according to said distance which is optimum when said readout means scans said groove;
• a step of generating focussing error signals controlling the distance between said readout means and said recording medium;
• a step of correcting an average value of said focussing error signals according to the deviation from an initial setting of the average value to generate second focussing error signals;
• a step of detecting which of the land and the groove said readout means is scanning;
• a step of selecting said first bias value or said second bias value according to the results of detection to correct said second focussing error signals by the selected bias value;
• and
• a step of driving said readout means according to the corrected second focussing error signals to control said distance.