Information recording medium with index header

Abstract

An information recording medium has a plurality of stacked recording layers. Each recording layer has a spiral track which defines a plurality of rounds, and at least one index header aligned in the radial direction of the disk to partially intercept the spiral track. The index header has address data of each round of the spiral track, which is formed by embossed pits, and some or all of the index headers of the first and second recording layers are laid out to overlap each other when viewed from the predetermined surface.

1 - 11 . (canceled)  
   
   
       12 . A disk-shaped information recording medium  15  comprising: 
 a spiral track; and    at least one index header aligned in a radial direction of the disk to partially intercept said spiral track,    said index header having address data recorded as an embossed pattern, said spiral track having an area where a plurality of recording fields each having a predetermined track length are recorded,    each of said recording fields having a header field and a data field,    said header field having address data,    said data field having an area for recording user data,    a specific one of said recording fields being recorded on said spiral track to extend across said index header,    the specific recording field having first and second sub recording fields to have said index header as a boundary,    said first sub recording field having a first header field,    said second sub recording field having a second header field,    said first and second header fields having identical address data, and    said recording fields being recorded or reproduced at a constant linear velocity.    
   
   
       13 . A medium according to  claim 12 , wherein said data field of said recording field records data having one ECC block length.  
   
   
       14 . A medium according to  claim 12 , wherein wobbles of a constant cycle start from one end of a track formed between the neighboring index headers, and a track area corresponding to wobbles less than one cycle at the other end of the track is used as an adjustment area.  
   
   
       15 . A medium according to  claim 12 , wherein each of said recording fields is formed in units of sync frames, and 
 one of said first and second sub recording fields of the specific recording field, which is less than one sync frame unit, is used as an adjustment field.    
   
   
       16 - 19 . (canceled)  
   
   
       20 . An information recording apparatus for recording information on a disk-shaped information recording medium, which comprises: 
 a spiral track having wobbles of a constant cycle; and    at least one index header aligned in a radial direction of the disk to partially intercept said spiral track, and    in which said index header has address data recorded as an embossed pattern,    said apparatus comprising:    recording field recording means for recording a plurality of recording fields each having a header field and a data field at a constant linear velocity on said spiral track on the basis of a signal obtained from the wobbles, recording a specific one of said recording fields on said spiral track across said index header, recording first and second sub recording fields in the specific recording field to have said index header as a boundary, and recording identical address data in a first header field of said first sub recording field and a second header field of said second sub recording field.    
   
   
       21 . An apparatus according to  claim 20 , wherein said recording field recording means records data for one ECC block length in the data field.  
   
   
       22 . An apparatus according to  claim 20 , wherein wobbles of a constant cycle start from one end of a track formed between the neighboring index headers, and a track area corresponding to wobbles less than one cycle at the other end of the track is used as an adjustment area, and 
 specific information is recorded in the adjustment area.    
   
   
       23 . An apparatus according to  claim 20 , wherein each of said recording fields is formed in units of sync frames, 
 one of said first and second sub recording fields of the specific recording field, which is less than one sync frame unit, is used as an adjustment field, and    said recording field recording means records specific information in the adjustment area.    
   
   
       24 - 27 . (canceled)  
   
   
       28 . An information recording method for recording information on a disk-shaped information recording medium, which comprises: 
 a spiral track having wobbles of a constant cycle; and    at least one index header aligned in a radial direction of the disk to partially intercept said spiral track, and    in which said index header has address data recorded as an embossed pattern,    said method comprising the step of:    recording a plurality of recording fields each having a header field and a data field at a constant linear velocity on said spiral track on the basis of a signal obtained from the wobbles, recording a specific one of said recording fields on said spiral track across said index header, recording first and second sub recording fields in the specific recording field to have said index header as a boundary, and recording identical address data in a first header field of said first sub recording field and a second header field of said second sub recording field.    
   
   
       29 . A method according to  claim 28 , wherein data for one ECC block length is recorded in the data field.  
   
   
       30 . A method according to  claim 28 , wherein wobbles of a constant cycle start from one end of a track formed between the neighboring index headers, and a track area corresponding to wobbles less than one cycle at the other end of the track is used as an adjustment area, and 
 specific information is recorded in the adjustment area.    
   
   
       31 . A method according to  claim 28 , wherein each of said recording fields is formed in units of sync frames, 
 one of said first and second sub recording fields of the specific recording field, which is less than one sync frame unit, is used as an adjustment field, and specific information is recorded in the adjustment area.    
   
   
       32 . (canceled)  
   
   
       33 . (canceled)  
   
   
       34 . An information reproduction apparatus for reproducing information from a disk-shaped information recording medium, which comprises: 
 a spiral track which has wobbles of a constant cycle, and on which a plurality of recording fields each having a predetermined track length are recorded; and    at least one index header aligned in a radial direction of the disk to partially intercept said spiral track, and    in which said index header has address data recorded as an embossed pattern,    each of said recording fields has a header field and a data field,    said header field has address data,    said data field has an area for recording user data,    a specific one of said recording fields is recorded on said spiral track across said index header,    the specific recording field has first and second sub recording fields to have said index header as a boundary,    said first sub recording field has a first header field,    said second sub recording field has a second header field, and said first and second header fields have identical address data,    said apparatus comprising:    reproduction means for reproducing said recording fields at a constant linear velocity on the basis of a signal obtained from the wobbles.    
   
   
       35 . (canceled)  
   
   
       36 . (canceled)  
   
   
       37 . An information reproduction method for reproducing information from a disk-shaped information recording medium, which comprises: 
 a spiral track which has wobbles of a constant cycle, and on which a plurality of recording fields each having a predetermined track length are recorded; and    at least one index header aligned in a radial direction of the disk to partially intercept said spiral track, and    in which said index header has address data recorded as an embossed pattern,    each of said recording fields has a header field and a data field,    said header field has address data,    said data field has an area for recording user data,    a specific one of said recording fields is recorded on said spiral track across said index header,    the specific recording field has first and second sub recording fields to have said index header as a boundary,    said first sub recording field has a first header field,    said second sub recording field has a second header field, and    said first and second header fields have identical address data,    said method comprising the step of:    reproducing said recording fields at a constant linear velocity on the basis of a signal obtained from the wobbles.