Multi-layered disc and multi-layered disc reproducing apparatus

Abstract

A multi-layered disc (D 1, D 2, D 3 ) is provided with a plurality of recording layers laminated with each other in a direction of a normal line of the recording layers, in each of which an information data recording area ( 2, 4 ) for recording information data and a control data recording area ( 1, 3 ) for recording control data to control an operation of recording and/or reproducing the information data are disposed on a same plane, the control data being recorded by a CAV method over a plurality of tracks in the control data recording area. The control data recording area in each of the recording layers is disposed such that the control data recording area ( 1 ) of one of the recording layers is not superimposed with the control data recording area ( 3 ) of another of the recording layers in the direction of the normal line.

1 - 14 . (canceled)  
   
   
       15 . A multi-layered disc comprising a plurality of recording layers laminated with each other in a direction of a normal line of said recording layers, in each of which an information data recording area for recording information data and a control data recording area for recording control data to control an operation of recording and/or reproducing the information data are disposed on a same plane, the control data being recorded by a CAV (Constant Angular Velocity) method over a plurality of tracks as a pit-row in advance in said control data recording area, 
 said control data being recorded in only one of said recording layers.    
   
   
       16 . A multi-layered disc according to  claim 15 , wherein 
 the plurality of recording layers are two recording layers,    said control data is recorded in only a recording layer which is disposed on farther side from an irradiation side of a reading light, from among the two recording layers.    
   
   
       17 . A multi-layered disc reproducing apparatus for reproducing information data recorded on a multi-layered disc comprising a plurality of recording layers laminated with each other in a direction of a normal line of said recording layers, in each of which an information data recording area for recording the information data and a control data recording area for recording control data to control an operation of recording and/or reproducing the information data are disposed on a same plane, the control data being recorded by a CAV (Constant Angular Velocity) method over a plurality of tracks as a pit-row in advance in said control data recording area, said control data being recorded in only one of said recording layers, said multi-layered disc reproducing apparatus comprising: 
 a detection signal outputting device for outputting a detection signal, which carries the control data in said control data recording area, on the basis of a reflected light obtained by an irradiation of a reading light onto said control data recording area;    a control data reproducing device for reproducing the control data on the basis of the detection signal outputted from said detection signal outputting device; and    an information data reproduction controlling device for reproducing the information data recorded in said information data recording area on the basis of the reproduced control data,    said control data reproducing apparatus comprising:    a low pass filter for extracting a control data signal based on the control data from the detection signal; and    a control data decoder for generating the control data by the control data signal extracted by said low pass filter.