Recording disc and apparatus and method for reproducing recorded information

Abstract

A recording disc and recorded information reproducing apparatus and method for immediately starting reproduction of information when a push-pull based tracking control is employed to reproduce recorded information from the recording disc. The recording disc comprises an information data area for recording recording marks which carry information data in columns, and a control data area for recording identification information indicative of a recording pattern of the recording marks in the information data area.

1 . A recording disk, comprising: 
 a first recording layer comprising a first recording track;    a second recording layer comprising a second recording track;    a control data area in which identification information is recorded,    wherein the identification information indicates a polarity of a first push-pull signal obtained from the first recording layer, and    wherein said identification information is recorded in said control data area a plurality of times in a direction perpendicular to said first recording track or said second recording track.    
   
   
       2 . The recording disk as claimed in  claim 1 , wherein said identification information comprises: 
 first information that indicates the polarity of the first push-pull signal obtained from the first recording layer; and    second information that indicates a polarity of a second push-pull signal obtained from the second recording layer.    
   
   
       3 . The recording disk as claimed in  claim 1 , wherein said control data area comprises a Phase Encoded Part (PEP) area.  
   
   
       4 . The recording disk as claimed in  claim 2 , wherein said control data area comprises a Phase Encoded Part (PEP) area.  
   
   
       5 . The recording disk as claimed in  claim 1 , wherein said identification information is structured so that a reproduction apparatus can read said identification information from said recording disk while a tracking servo of said reproduction apparatus is in an open state.  
   
   
       6 . The recording disk as claimed in  claim 2 , wherein said identification information is structured so that a reproduction apparatus can read said identification information from said recording disk while a tracking servo of said reproduction apparatus is in an open state.  
   
   
       7 . The recording disk as claimed in  claim 3 , wherein said identification information is structured so that a reproduction apparatus can read said identification information from said recording disk while a tracking servo of said reproduction apparatus is in an open state.  
   
   
       8 . A recording disk as claimed in  claim 4 , wherein said identification information is structured so that a reproduction apparatus can read said identification information from said recording disk while a tracking servo of said reproduction apparatus is in an open state.  
   
   
       9 . A recording disk, comprising: 
 an information area in which information is recorded on a recording track; and    a control data area in which identification information is recorded, wherein said identification information indicates a polarity of a push-pull signal obtained from said information area;    wherein said identification information is recorded in said control data area a plurality of times in a direction perpendicular to the recording track.    
   
   
       10 . A recording disk, comprising: 
 an information area for recording information; and    a control data area in which identification information is recorded,    wherein said identification information indicates a polarity of a push-pull signal obtained from said information area,    wherein said identification information is recorded in said control data area a plurality of times in a direction perpendicular to a recording track of the recording disk.    
   
   
       11 . A reproducing apparatus for reproducing recorded information from a recording disk, said reproducing apparatus comprising: 
 a reproduction circuit that generates a readout signal by projecting a light beam onto a recording layer of the recording disk and opto-electrically converting a reflection light from the recording layer;    a processing circuit that restores identification information recorded in a control data area of the recording disk based on said readout signal and that generates a push-pull signal based on the readout signal, wherein the identification information indicates a polarity of the push-pull signal obtained from the recording layer; and    a tracking servo circuit that shifts an optical axis of the light beam in a direction perpendicular to a recording track of the recording layer in accordance with said push-pull signal,    wherein the identification information is recorded a plurality of times in a direction perpendicular to the recording track.    
   
   
       12 . A reproducing method for reproducing information from a recording disk having a plurality of recording layers and a control data area, said reproducing method comprising: 
 projecting a light beam onto one of the recording layers of the recording disk and reading a readout signal from the recording disk;    restoring identification information recorded in the control data area of the recording disk based on the readout signal;    generating a push-pull signal based on said identification information and said readout signal; and    shifting an optical axis of the light beam in a direction perpendicular to a recording track of one of the recording layers in accordance with the push-pull signal,    wherein the identification information indicates a polarity of the push-pull signal, and    wherein the identification information is recorded a plurality of times in a direction perpendicular to the recording track.