Tracing controlling apparatus

Application Number  00128872 Application Date  2000.09.22
Publication Number  1289116 Publication Date  2001.03.28
Priority Information   1999/9/22 JP 268184/99  
International
Classification
 G11B7/09;G11B21/10  
Applicant(s) Name  Nippon Pioneer Co.  
Address    
Inventor(s) Name  Tanagisawa Takuma;Kurihayashi Sukemoto  
Patent Agency Code  72001 Patent Agent  wang yue
AbstractA disc has a physical factor changing a shape or a reflection coefficient in a tangential direction of a record track. A tracking control apparatus for the disc is provided with: a detecting device, a second detector, a third detector and a fourth detector; a first amplifying device, a second amplifying device; a first adding device for calculating a first sum signal; a second adding device for calculating a second sum signal; and a first subtracting device for calculating a difference between the first an second sum signals and outputting the difference as a tracking error signal. The tracking control apparatus is also provided with an amplitude comparing device for determining the first gain and the second gain on the basis of differences between the output signals.