Method of optimizing the write power for recording marks in an information layer of a record carrier and recording device using such an optimizing method

Abstract

A method of optimizing the write power for recording marks in an information layer of a record carrier by irradiating the information layer with a (pulsed) radiation beam. The method includes recording a pattern of test marks including short marks having a predetermined short nominal runlength onto the record carrier by applying at least three different write powers; measuring the runlengths of the recorded short marks obtained by applying the at least three different write powers; and determining an optimum write power based of the deviations of the measured runlengths from the nominal runlength of said short marks.

1 . A method of optimizing write power for recording marks in an information layer of a record carrier by irradiating the information layer with a radiation beam, said information layer having a phase that is reversibly changeable between a first phase and a second phase, comprising the acts of:
 recording a pattern of test marks at least comprising short marks having a predetermined short nominal runlength onto the record carrier by applying at least three different write powers,   measuring the runlengths of said short marks recorded through the application of the at least three different write powers,   determining an optimum write power based on a function of the deviations of the measured runlengths from the nominal runlength of said short marks and the jitter of said short marks, and   selecting the optimum write power associated with a deviation value that corresponds approximately to a minimum jitter value from the function.   
     
     
         2 - 3 . (canceled) 
     
     
         4 . The method as claimed in  claim 1 ,
 wherein, in said act of recording a pattern of test marks, shortest marks having the shortest runlength allowed by an applied modulation method are recorded, and wherein the runlengths of said shortest marks are measured and used for determining the optimum write power.   
     
     
         5 . The method as claimed in  claim 1 ,
 wherein, in said act of recording a pattern of test marks, the test marks are recorded in that the at least three different write powers around a default optimum write power are applied.   
     
     
         6 . The method as claimed in  claim 1 ,
 further comprising the acts of:
 recording marks including short marks onto the record carrier by applying the determined optimum write power, 
 measuring the runlengths of said short marks thus recorded by means of the determined optimum write power, 
 adjusting the optimum write power based on the difference between the measured runlengths and the nominal runlength of said short marks. 
   
     
     
         7 . The method as claimed in  claim 1 ,
 further comprising the acts of:
 measuring modulations of said recorded short marks recorded by means of the at least three different write powers, 
 checking whether the applied write powers result in a modulation of the recorded short marks that lies above a predetermined threshold modulation. 
   
     
     
         8 . The method
   claim 1 ,
 further comprising the act of recording said marks representing user data by applying said optimum write power.     
     
     
         9 . The method
 of  claim 1 , further comprising the act of optimizing the write power for recording said marks by regularly repeating the acts of recording, measuring and selecting to adjust the optimum write power regularly during said recording.   
     
     
         10 . A device for optimizing the write power for recording marks in an information layer of a record carrier the device comprising:
 a recorder for recording a pattern of test marks at least comprising short marks having a predetermined short nominal runlength onto the record carrier by applying at least three different write powers,   a detector for measuring the runlengths of said short marks recorded by the application of the at least three different write powers, and   processor means for determining an optimum write power based on a function of the deviations of the measured runlengths from the nominal runlength of said short marks and jitter of said short marks, and for selecting the optimum write power associated with a deviation value that corresponds approximately to a minimum jitter value from the function.   
     
     
         11 . A recording device for recording the marks in the information layer of the record carrier by irradiating the information layer with a radiation beam, comprising the device of  claim 10 . 
     
     
         12 . The recording device as claimed in  claim 11 ,
 wherein the recorder records the test marks including the short marks onto the record carrier by applying the determined optimum write power, and   the detector measures the runlengths of said short marks recorded by means of the determined optimum write power, and   the processor adjusts the optimum write power based on the deviation of the measured runlengths from the nominal runlength of said short marks.   
     
     
         13 . (canceled) 
     
     
         14 . A method of optimizing write power for recording marks in an information layer of a record carrier by irradiating the information layer with a radiation beam, the method comprising the acts of:
 recording a pattern of test marks comprising marks having a predetermined nominal runlength onto the record carrier by applying at least three different write powers;   measuring runlengths of said recorded marks;   determining a jitter function of the deviation values of the measured runlengths from the nominal runlength of said marks and the jitter values of said marks;   determining from the function a deviation value that corresponds to a minimum jitter value;   determining a power function of write power values versus the deviation values; and   selecting from the power curve the optimum write power associated with the deviation value corresponding approximately to the minimum jitter value.   
     
     
         15 . The method of  claim 14 , further comprising the acts of:
 measuring modulation values of said marks recorded with the at least three different write powers;   determining a modulation function of the deviation values versus the measured modulation values; and   selecting from the modulation function selected deviation values corresponding to measured modulation values that are above a predetermined threshold modulation value.   
     
     
         16 . The method of  claim 14 , further comprising the acts of:
 measuring modulation values of said marks recorded with the at least three different write powers; and   re-recording the pattern of test marks if the measuring modulation values are below a predetermined threshold modulation value.   
     
     
         17 . The method of  claim 14 , wherein the jitter values correspond to jitter values of lands of the information layer. 
     
     
         18 . The method of  claim 14 , wherein the marks have a shortest runlength allowed by an applied modulation used for the recording act. 
     
     
         19 . Method of optimizing the write power for recording marks in an information layer of a record carrier by irradiating the information layer with a radiation beam, said information layer having a phase that is reversibly changeable between a first phase and a second phase, comprising
 a recording step of recording (S 1 ) a pattern of test marks onto the record carrier by applying different write powers, and   a determining step of determining (S 4 ) an optimum write power on the basis of the recorded marks,   
       wherein:
 the pattern of test marks comprises short marks having a predetermined short nominal runlength, and 
 the short marks are recorded in the recording step by applying at least three different write powers, 
 
       and
 the method further comprises a measuring step for measuring (S 2 ) the runlengths of said short marks recorded through the application of the at least three different write powers, 
 
       and
 in the determining step the optimum write power is determined on the basis of the deviations of the measured runlengths from the nominal runlength of said short marks. 
 
     
     
         20 . Method as claimed in  claim 19 , 
       wherein in the determining step the optimum write power is determined on the basis of the deviations of the measured runlengths from the nominal runlength of said short marks, such that the difference between a measured runlength and the nominal runlength of said short marks is substantially zero. 
     
     
         21 . Method as claimed in  claim 19 , 
       wherein in the determining step the optimum write power is determined on the basis of the deviations of the measured runlengths from the nominal runlength of said short marks, such that the jitter of said short marks is minimal. 
     
     
         22 . Method as claimed in  claim 19 , 
       wherein in the recording step (S 1 ) shortest marks having the shortest runlength allowed by an applied modulation method are recorded, and wherein in the measuring step the runlengths of said shortest marks are measured and used for determining the optimum write power in the determining step. 
     
     
         23 . Method as claimed in  claim 19 , 
       wherein in the recording step (S 1 ) at least three different write powers around a default optimum write power are applied. 
     
     
         24 . Method as claimed in  claim 19 ,
 further comprising the steps of:
 recording (S 5 ) marks including short marks onto the record carrier by applying the determined optimum write power, 
 measuring (S 6 ) the runlengths of said short marks thus recorded by means of the determined optimum write power, 
 adjusting (S 7 ) the optimum write power on the basis of the difference between the measured runlengths and the nominal runlength of said short marks. 
   
     
     
         25 . Method as claimed in  claim 19 ,
 further comprising the steps of:
 measuring (S 2 ) the modulations of said recorded short marks recorded by means of the at least three different write powers, 
 checking (S 3 ) whether the applied write powers result in a modulation of the recorded short marks that lies above a predetermined threshold modulation. 
   
     
     
         26 . Recording method for recording marks representing user data in an information layer of a record carrier by irradiating the information layer with a radiation beam, said information layer having a phase that is reversibly changeable between a first phase and a second phase, comprising the steps of:
 optimizing the write power for recording said marks by a method as claimed in  claim 19 , so as to obtain an optimum write power, and   recording said marks representing user data by applying said optimum write power.   
     
     
         27 . Recording method for recording marks representing user data in an information layer of a record carrier by irradiating the information layer with a radiation beam, said information layer having a phase that is reversibly changeable between a first phase and a second phase, comprising the steps of:
 optimizing the write power for recording said marks by regularly carrying out a method as claimed in  claim 19  to adjust the optimum write power regularly during said recording.   
     
     
         28 . Device for optimizing the write power for recording marks in an information layer of a record carrier by a method as claimed in  claim 19 , comprising
 recording means for recording a pattern of test marks onto the record carrier by applying different write powers, and   determining means for determining an optimum write power on the basis of the recorded marks,   
       wherein
 the pattern of test marks comprises short marks having a predetermined short nominal runlength, which short marks are recorded in the recording step by applying at least three different write powers, 
 
       and
 the device further comprises a measuring means for measuring the runlengths of said short marks recorded through the application of the at least three different write powers, 
 
       and
 determining means are adapted for determining the optimum write power on the basis of the deviations of the measured runlengths from the nominal runlength of said short marks. 
 
     
     
         29 . Recording device for recording marks in an information layer of a record carrier by irradiating the information layer with a radiation beam, comprising a device for optimizing the write power for recording marks in an information layer of a record carrier as claimed in  claim 28 . 
     
     
         30 . Recording device as claimed in  claim 29 , further comprising
 further recording means for recording marks including short marks onto the record carrier by applying the determined optimum write power,   further measuring means for measuring the runlengths of said short marks recorded by means of the determined optimum write power, and   adjusting means for adjusting the optimum write power on the basis of the deviation of the measured runlengths from the nominal runlength of said short marks.   
     
     
         31 . Recording device as claimed in  claim 30  adapted for optimizing the write power for recording said marks by regularly carrying out a method as claimed in  claim 24  for regularly adjusting the optimum write power.