Information storage medium, information recording apparatus, and information reproduction apparatus

Abstract

An information storage medium according to an embodiment of this invention has an area for storing predetermined data modulated according to the (d, k; m, n) modulation rule. The predetermined data includes at least one SYNC code in a predetermined recording unit, and the number of “1”s included in a predetermined number of a series of channel bits at an arbitrary position in the SYNC code is not more than a half the predetermined number.

1 . An information storage medium comprising: 
 a management area that stores management information; and    a data area that stores predetermined data in predetermined recording units, wherein the predetermined data is modulated according to a (d, k; m, n) modulation rule,    the (d, k; m, n) modulation rule modulates m-bit source data into n-channel bit data, so that modulated channel bit patterns satisfy conditions that a minimum of d pieces of 0s successively arranged and a maximum of k pieces of 0s successively arranged,    the predetermined data includes a plurality of SYNC codes in the predetermined recording unit,    the number of 1s included in a predetermined number of a series of channel bits at an arbitrary position in the SYNC code is not more than a half the predetermined number,    each of the plurality of SYNC codes includes a fixed code and a variable code.    the fixed code includes k or more sequences of 0s successively arranged and d+1 sequences of 0s successively arranged,    the variable code is one of a first pattern, a second pattern and a pattern other than the first pattern and second pattern,    combinations of the variable codes of three successive SYNC codes in the predetermined recording unit are different from one another,    first 4 bits of the first pattern are assigned 0100 or 1000 and    first 2 bits of the second pattern are assigned 00, or first 5 bits of the second pattern are assigned 10100.    
   
   
       2 . A medium according to  claim 1 , wherein all patterns contained in the SYNC code satisfy a condition that the number of 1s included in a series of N channel bits is not more than INT[N/(d+1)], 
 where INT[X] is an integer value obtained by dropping digits after the decimal point of X, and    N is given by N={(d+1)×INT[9/(d+1)]}+1.    
   
   
       3 . A medium according to  claim 1 , wherein not less than 66% of patterns contained in the SYNC code satisfy a condition that the number of 1s included in a series of (N−1) channel bits is not more than INT[(N−1)/(d+1)]−1, 
 where INT[X] is an integer value obtained by dropping digits after the decimal point of X, and    N is given by N={(d+1)×INT[9/(d+1)]}+1.    
   
   
       4 . A medium according to  claim 1 , wherein the predetermined data stored in said information storage medium is modulated according to a (1, k; m, n) modulation rule, and 
 all patterns contained in the SYNC code satisfy a condition that the number of 1s included in a series of 9 channel bits is not more than 4.    
   
   
       5 . A medium according to  claim 1 , wherein the predetermined data stored in said information storage medium is modulated according to a (1, k; m, n) modulation rule, and 
 not less than 66% of patterns contained in the SYNC code satisfy a condition that the number of 1s included in a series of 8 channel bits is not more than 3.    
   
   
       6 . An information recording apparatus for recording information on an information storage medium, comprising: 
 a generation unit configured to generate predetermined data; and    a recording unit configured to record the predetermined data,    wherein the predetermined data is modulated according to a (d, k; m, n) modulation rule,    the (d, k; m, n) modulation rule modulates m-bit source data into n-channel bit data, so that modulated channel bit patterns satisfy conditions that a minimum of d pieces of 0s successively arranged and a maximum of k pieces of 0s successively arranged,    the predetermined data includes a plurality of SYNC codes in the predetermined recording unit,    the number of 1s included in a predetermined number of a series of channel bits at an arbitrary position in the SYNC code is not more than a half the predetermined numbers    each of the plurality of SYNC codes includes a fixed code and a variable code,    the fixed code includes k or more sequences of 0s successively arranged and d+1 sequences of 0s successively arranged,    the variable code is one of a first pattern, a second pattern and a pattern other than the first pattern and second pattern,    the variable code of the lead of the SYNC codes in the predetermined recording unit is the first pattern,    combinations of the variable codes of three successive SYNC codes in the predetermined recording unit are different from one another,    first 4 bits of the first pattern are assigned 0100 or 1000, and    first 2 bits of the second pattern are assigned 00, or first 5 bits of the second pattern are assigned 10100.    
   
   
       7 . An apparatus according to  claim 6 , wherein all patterns contained in the SYNC code satisfy a condition that the number of 1s included in a series of N channel bits is not more than INT[N/(d+1)], 
 where INT[X] is an integer value obtained by dropping digits after the decimal point of X, and    N is given by N={(d+1)×INT[9/(d+1)])}+1.    
   
   
       8 . An apparatus according to  claim 6 , wherein not less than 66% of patterns contained in the SYNC code satisfy a condition that the number of 1s included in a series of (N−1) channel bits is not more than INT[(N−1)/(d+1)]−1. 
 where INT[X] is an integer value obtained by dropping digits after the decimal point of X, and    N is given by N={(d+1)×INT[9/(d+1)]}+1.    
   
   
       9 . An information reproduction apparatus for reproducing information from an information storage medium, comprising: 
 a read unit configured to read out predetermined data from the information storage medium, and    a reproduction unit configured to reproduce various data on the basis of a SYNC code contained in the predetermined data,    wherein the predetermined data is modulated according to a (d, k; m, n) modulation rule,    the (d, k; m, n) modulation rule modulates m-bit source data into n-channel bit data, so that modulated channel bit patterns satisfy conditions that a minimum of d pieces of 0s successively arranged and a maximum of k pieces of 0s successively arranged,    the predetermined data includes a plurality of SYNC codes in the predetermined recording unit,    the number of 1s included in a predetermined number of a series of channel bits at an arbitrary position in the SYNC code is not more than a half the predetermined numbers    each of the plurality of SYNC codes includes a fixed code and a variable code.    the fixed code includes k or more sequences of 0s successively arranged and d+1 sequences of 0s successively arranged,    the variable code is one of a first pattern, a second pattern and a pattern other than the first pattern and second pattern.    combinations of the variable codes of three successive SYNC codes in the predetermined recording unit are different from one another,    first 4 bits of the first pattern are assigned 0100 or 1000, and    first 2 bits of the second pattern are assigned 00, or first 5 bits of the second pattern are assigned 10100.    
   
   
       10 . An apparatus according to  claim 9 , wherein all patterns contained in the SYNC code satisfy a condition that the number of 1s included in a series of N channel bits is not more than INT[N/(d+1)], 
 where INT[X] is an integer value obtained by dropping digits after the decimal point of X, and    N is given by N={(d+1)×INT[9/(d+1)]}+1.    
   
   
       11 . An apparatus according to  claim 9 , wherein not less than 66% of patterns contained in the SYNC code satisfy a condition that the number of 1s is included in a series of (N−1) channel bits is not more than INT[(N−1)/(d+1)]−1, 
 where INT[X] is an integer value obtained by dropping digits after the decimal point of X, and    N is given by N={(d+1)×INT[9/(d+1)]}+1.    
   
   
       12 . An information recording method for recording information on an information storage medium, comprising: 
 generation predetermined data; and    recording the predetermined data,    wherein the predetermined data is modulated according to a (d, k; m, n) modulation rule,    the (d, k; m, n) modulation rule modulates m-bit source data into n-channel bit data, so that modulated channel bit patterns satisfy conditions that a minimum of d pieces of 0s successively arranged and a maximum of k pieces of 0s successively arranged,    the predetermined data includes a plurality of SYNC codes in the predetermined recording unit,    the number of 1s included in a predetermined number of a series of channel bits at an arbitrary position in the SYNC code is not more than a half the predetermined number,    each of the plurality of SYNC codes includes a fixed code and a variable code,    the fixed code includes k or more sequences of 0s successively arranged and d+1 sequences of 0s successively arranged,    the variable code is one of a first pattern, a second pattern and a pattern other than the first pattern and second pattern,    the variable code of the lead of the SYNC codes in the predetermined recording unit is the first pattern,    combinations of the variable codes of three successive SYNC codes in the predetermined recording unit are different from one another,    first 4 bits of the first pattern are assigned 0100 or 1000, and    first 2 bits of the second pattern are assigned 00, or first 5 bits of the second pattern are assigned 10100.    
   
   
       13 . A method according to  claim 12 , wherein all patterns contained in the SYNC code satisfy a condition that the number of 1s included in a series of N channel bits is not more than INT[N/(d+1)], 
 where INT[X] is an integer value obtained by dropping digits after the decimal point of X, and    N is given by N={(d+1)×INT[9/(d+1)]}+1.    
   
   
       14 . A method according to  claim 12 , wherein not less than 66% of patterns contained in the SYNC code satisfy a condition that the number of 1s included in a series of (N−1) channel bits is not more than INT[(N−1)/(d+1)]−1, 
 where INT[X] is an integer value obtained by dropping digits after the decimal point of X, and    N is given by N={(d+1)×INT[9/(d+1)]}+1.    
   
   
       15 . An information reproduction method for reproducing information from an information storage medium, comprising: 
 reading out predetermined data from the information storage medium, and    reproducing various data on the basis of a SYNC code contained in the predetermined data,    wherein the predetermined data is modulated according to a (d, k; m, n) modulation rule,    the (d, k; m, n) modulation rule modulates m-bit source data into n-channel bit data, so that modulated channel bit patterns satisfy conditions that a minimum of d pieces of 0s successively arranged and a maximum of k pieces of 0s successively arranged,    the predetermined data includes a plurality of SYNC codes in the predetermined recording unit,    the number of 1s included in a predetermined number of a series of channel bits at an arbitrary position in the SYNC code is not more than a half the predetermined number,    each of the plurality of SYNC codes includes a fixed code and a variable code,    the fixed code includes k or more sequences of 0s successively arranged and d+1 sequences of 0s successively arranged,    the variable code is one of a first pattern, a second pattern and a pattern other than the first pattern and second pattern,    combinations of the variable codes of three successive SYNC codes in the predetermined recording unit are different from one another,    first 4 bits of the first pattern are assigned 0100 or 1000, and    first 2 bits of the second pattern are assigned 00, or first 5 bits of the second pattern are assigned 10100.    
   
   
       16 . A method according to  claim 15 , wherein all patterns contained in the SYNC code satisfy a condition that the number of 1s included in a series of N channel bits is not more than INT[N/(d+1)], 
 where INT[X] is an integer value obtained by dropping digits after the decimal point of X, and    N is given by N={(d+1)×INT[9/(d+1)]}+1.    
   
   
       17 . A method according to  claim 15 , wherein not less than 66% of patterns contained in the SYNC code satisfy a condition that the number of 1s included in a series of (N−1) channel bits is not more than INT[(N−1)/(d+1)]−1, 
 where INT[X] is an integer value obtained by dropping digits after the decimal point of X, and    N is given by N={(d+1)×INT[9/(d+1)]}+1.