Apparatus for generating tracking error signals

Abstract

An apparatus for generating tracking error signals including: an optical detection unit having a plurality of divided light receiving elements to allow beams reflected from a recording surface of the optical disks to be incident; a comparator for outputting after comparing the signals from light receiving elements, which correspond to the set group of the optical detection unit, with the reference signals set for the each group; an error correction unit for correcting and outputting errors if there are any errors after mutual comparison with signals of the groups output from the comparator; a phase-difference detection unit for outputting the signals for each group that correspond to a phase-difference after mutual comparison of the signals of the groups output from the error correction unit; a subtractor for mutually subtracting the signals for each group from the phase-difference detection unit and outputting the tracking error signals.

1 .- 5 . (canceled)  
   
   
       6 . An apparatus for generating tracking error signals, comprising: 
 an optical detection unit, having a plurality of divided light receiving elements, for receiving the beams reflected from the recording surface of optical disks;    a plural comparators for comparing the signals from each light receiving element of the optical detection unit with the set reference signals and outputting the signals;    an error correction unit for mutually comparing the signals of the compared results from the comparators belonging to groups of light receiving elements placed in the opposite direction from the optical detection unit;    a phase-difference detection unit for mutually comparing the signals corresponding to each light receiving element from the error correction unit with signals belonging to the group and outputting the signals corresponding to the phase-difference to correspond to each light receiving element;    an adder for mutually adding up the signals corresponding to light receiving elements placed in the diagonal direction of the optical detection unit for signals which are output to correspond to the light receiving elements from the phase-difference detection unit;    a subtractor for mutually subtracting the signals from the adder and outputs them as the tracking error signals.    
   
   
       7 . The method according to  claim 6 , wherein an optical detection unit typically includes quarterly-divided light receiving elements.  
   
   
       8 . The method according to  claim 7 , wherein an error correction unit comprises: 
 a first error correction unit for mutually comparing the signals from the comparator corresponding to the first and second light receiving elements placed in the opposite direction out of the quarterly-divided light receiving elements, determining if there are any errors, outputting after correcting the signals; and    a second error correction unit for mutually comparing the signals from the comparator corresponding to the third and fourth light receiving elements placed in the opposite direction out of the quarterly-divided light receiving elements, determining if there are any errors, outputting after correcting the signals.    
   
   
       9 . The method according to  claim 8 , wherein a phase-difference detection unit comprises: 
 a first phase-difference detection unit for mutually comparing the signals corresponding to the first and second light receiving elements from the first error correction unit and outputting signals corresponding to the phase-difference to correspond to the first and second light receiving elements;    a second phase-difference detection unit for mutually comparing the signals corresponding to the third and fourth light receiving elements from the first error correction unit and outputting the signals corresponding to the phase-difference to correspond to the third and fourth light receiving elements;    a first OR gate for making a mutual logical adding of the signals output to correspond to the first light receiving element from the first phase-difference detection unit and the signals output to correspond to the third light receiving elements from the second phase-difference detection unit and then outputting them to the subtractor;    a second OR gate for making a mutual logical adding of the signals output to correspond to the second light receiving element from the first phase-difference detection unit and the signals output to correspond to the fourth light receiving elements from the second phase-difference detection unit and then outputting them to the subtractor.    
   
   
       10 . The method according to  claim 8 , wherein an error correction unit comprises: 
 a first switching unit for outputting the signals of the comparator connected with the first light receiving elements and the set first reference signals selectively to the phase-difference detection unit;    a second switching unit for outputting the signals of the comparator connected with the second light receiving elements and the set first reference signals selectively to the phase-difference detection unit;    a XOR gate for performing an exclusive logical adding operation of the signals from the comparator connected with the first light receiving elements and signals from the comparator connected with the second receiving elements;    an OR gate for performing a logical adding operation of the signals of the comparator connected with the first light receiving element and signals from the comparator connected with the second light receiving element; and    a pulse comparator for comparing the signals of both XOR gate and OR gate and controlling the first and second switching units for the second reference signals to be output for those corresponding to the same level mutually.    
   
   
       11 . The method according to  claim 11 , wherein a second error correction unit comprises: 
 a third switching unit for outputting the signals from the comparator connected with the third light receiving unit and the signals from the set first reference signals selectively to the phase-difference detection unit;    a fourth switching unit for outputting the signals from the comparator connected with the fourth light receiving elements and the signals from the first reference signals selectively to the phase-difference detection unit;    a XOR gate for performing an exclusive logical adding operation of the signals from the comparator connected with the third light receiving elements and the signals from the comparator connected with the fourth light receiving elements;    an OR gate for performing a logical adding operation of the signals from the comparator connected with the third light receiving elements and the signals from the comparator connected with the fourth light receiving elements; and    a pulse comparator for comparing the signals from the XOR gate and the signals from the OR gate, and controlling the third and fourth switching units for the first reference signals to be output for those corresponding to the same level mutually.    
   
   
       12 . (canceled)