Disc driving apparatus and information readout method

Abstract

A disc driving apparatus and an information readout method according to the present invention realize optimum servo control of a readout unit in reading out the information from a recording medium having lands and grooves. The disc driving apparatus includes a unit for correcting tracking error signals, a unit for inverting signals corrected by the correcting unit to generate inverted tracking error signals, a unit for detecting which of the lands and the grooves the readout unit is scanning, and a unit for selecting the tracking error signals or the inverted tracking error signals according to the results of detection by the detection unit to tracking-control the readout unit by the selected signals.

1 - 8 . (canceled)  
   
   
       9 . 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: 
 focusing error signal generating means for generating focusing 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 focusing error signals by the selected bias value; and    driving means for driving said readout means according to the focusing error signals corrected by said correction means to control said distance.    
   
   
       10 . (canceled)  
   
   
       11 . 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 focusing 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 focusing error signals by the selected bias value; and    a step of driving said readout means according to the corrected focusing error signals to control said distance.    
   
   
       12 . 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 focusing error signals controlling the distance between said readout means and said recording medium;    a step of correcting an average value of said focusing error signals according to the deviation from an initial setting of the average value to generate second focusing 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 focusing error signals by the selected bias value; and    a step of driving said readout means according to the corrected second focusing error signals to control said distance.