Methods and devices for recording marks in an information layer of an optical record carrier, and record carriers for use therein

Abstract

Methods and devices or writing an optical record carrier, in which a mark representing recorded data is written in a phase-change layer of a record carrier by a sequence of radiation pulses. A rear heating pulse is introduced after a last write pulse and a front heating pulse is introduced before the first write pulse. The power level of the front heating pulse and the power level of the rear heating pulse may be dependent on the length of the mark to be recorded and on properties of the record carrier.

1 . A method of recording marks representing data in a recording medium, the method comprising the acts of:
 providing a recording medium comprising an information layer having a phase which is reversibly changeable between a crystal phase and an amorphous phase, by irradiating the information layer with a pulsed radiation beam;   recording multiple marks where each mark is written by a sequence of pulses comprising at least one write pulse, the written marks being erasable by irradiating the information layer with a radiation beam having an erase power level, a first write pulse of a sequence of pulses being preceded by a cooling pulse having a cooling power level which is lower than the erase power level, said radiation beam being generated by a radiation source, wherein a last write pulse of a sequence is directly followed by a rear heating pulse having a rear heating power level, the rear heating power level being higher than the erase power level.   
     
     
         2 . The method as claimed in  claim 1 , wherein the rear heating power level of the rear heating pulse is dependent on properties of the recording medium. 
     
     
         3 . The method as claimed in  claim 1  for recording marks having lengths of nT, where T represents the length of one period of a reference clock in a data signal and n represents a predetermined number larger than 1, each mark being written by a sequence of (n−1) write pulses, wherein the rear heating pulse has a first rear heating power level when n=2, a second rear heating power level when n=3, and a third rear heating power level when n≧4, the first rear heating power level, the second rear heating power level, and the third rear heating power level being dependent on properties of the recording medium. 
     
     
         4 . The method as claimed in  claim 1 , wherein the first write pulse of a sequence is directly preceded by a front heating pulse having a front heating power level, the front heating pulse being directly preceded by the cooling pulse having a cooling power level, the front heating power level being higher than the erase power level. 
     
     
         5 . The method as claimed in  claim 4 , wherein the front heating power level of the front heating pulse is dependent on properties of the recording medium. 
     
     
         6 . The method as claimed in  claim 4  for recording marks having lengths of nT, where T represents the length of one period of a reference clock in a data signal and n represents a predetermined natural number larger than 1, each mark being written by a sequence of (n−1) write pulses, wherein the front heating pulse has a first front heating power level when n=2, a second front heating power level when n=3, and a third front heating power level when n≧4, the first front heating power level, the second front heating power level, and the third front heating power level being dependent on properties of the recording medium. 
     
     
         7 . The method as claimed in  claim 1 , wherein the cooling power level of the cooling pulse is dependent on properties of the radiation source and the recording medium. 
     
     
         8 . The method as claimed in  claim 4  for recording marks having lengths of nT, where T represents the length of one period of a reference clock in a data signal and n represents a predetermined natural number larger than 1, each mark being written by a sequence of (n−1) write pulses, wherein the cooling pulse has a first cooling power level when n=2, a second cooling power level when n=3, and a third cooling power level when n≧4, the first cooling power level, the second cooling power level, and the third cooling power level being dependent on properties of the radiation source and the recording medium. 
     
     
         9 . The method as claimed in  claim 1 , wherein the rear heating pulse includes a front portion having the rear heating power level, and a rear portion having a power level which is lower than the erase power level. 
     
     
         10 . A method of recording marks representing data in a recording medium, the method comprising the acts of:
 providing a recording medium comprising an information layer having a phase which is reversibly changeable between a crystal phase and an amorphous phase, by irradiating the information layer with a pulsed radiation beam; and   recording multiple marks where each mark has a length of nT, where T represents the length of one period of a reference clock in a data signal and n represents a predetermined natural number larger than 1, the marks being written by a sequence of pulses comprising (n−1) write pulses, the written marks being erasable by irradiating the information layer with a radiation beam having an erase power level, a first write pulse of a sequence of pulses being preceded by a cooling pulse having a cooling power level which is lower than the erase power level, said radiation beam being generated by a radiation source, wherein the cooling pulse has a first cooling power level when n=2, a second cooling power level when n=3, and a third cooling power level when n≧4, the first cooling power level, the second cooling power level, and the third cooling power level being dependent on properties the radiation source.   
     
     
         11 . The method as claimed in  claim 10 , wherein the first cooling power level is substantially equal to the second cooling power level and the third cooling power level. 
     
     
         12 . A recording device for recording data in the form of marks on a recording medium, said recording medium comprising an information layer having a phase which is reversibly changeable between a crystal phase and an amorphous phase, by irradiating the information layer with a pulsed radiation beam, the recorded marks being erasable by means of irradiating the information layer with a radiation beam having an erase power level, the device comprising a radiation source providing the radiation beam and a control unit for controlling the power of the radiation beam, the control unit being operative for providing a sequence of write pulses for writing a mark and controlling the power of the radiation beam such that it has a cooling power level which is lower than the erase power level preceding a first write pulse of a sequence of pulses, wherein the control unit is operative for controlling the power of the radiation beam such that it has a rear heating pulse having a rear heating power level directly following a last write pulse of a sequence, the rear heating power level being higher than the erase power level. 
     
     
         13 . The recording device as claimed in  claim 12 , wherein the recording device comprises means for determining a value for the rear heating power level, which value for the rear heating power level depends on properties of the recording medium. 
     
     
         14 . The recording device as claimed in  claim 12  for recording marks having lengths of nT, where T represents the length of one period of a reference clock in a data signal and n represents a predetermined natural number larger than 1, wherein the recording device comprises means for determining a first value for the rear heating power level when n=2,a second value for the rear heating power level when n=3, and a third value for the rear heating power level when n≧4, said first value for the rear heating power level, said second value for the rear heating power level and said third value for the rear heating power level being dependent on properties of the recording medium. 
     
     
         15 . The recording device as claimed in  claim 12 , wherein the control unit is operative for controlling the power of the radiation beam such that it has a front heating pulse having a front heating power level directly preceding a first write pulse and a cooling pulse having a cooling power level directly preceding the front heating pulse, the front heating power level being higher than the erase power level and the cooling power level being lower than the erase power level. 
     
     
         16 . The recording device as claimed in  claim 15 , wherein the recording device comprises means for determining a value for the front heating power level, which value for the front heating power level depends on properties of the recording medium. 
     
     
         17 . The recording device as claimed in  claim 15  for recording marks having lengths of nT, where T represents the length of one period of a reference clock in a data signal and n represents a predetermined natural number larger than 1,wherein the recording device comprises means for determining a first value for the front heating power level when n=2, a second value for the front heating power level when n=3, and a third value for the front heating power level when n≧4, said first value for the front heating power level, said second value for the front heating power level and said third value for the front heating power level being dependent on properties of the recording medium. 
     
     
         18 . The recording device as claimed in  claim 15 , wherein the recording device comprises means for determining a value for the cooling power level, which value for the cooling power level depends on properties of the recording medium. 
     
     
         19 . The recording device as claimed in  claim 15  for recording marks having lengths of nT, where T represents the length of one period of a reference clock in a data signal and n represents a predetermined natural number larger than 1, wherein the recording device comprises means for determining a first value for the cooling power level when n=2, a second value for the cooling power level when n=3, and a third value for the cooling power level when n≧4, said first value for the cooling power level, said second value for the cooling power level and said third value for the cooling power level being dependent on properties of the radiation source. 
     
     
         20 . The recording device as claimed in  claim 12 , wherein the control unit is operative for providing the rear heating pulse and controlling the power of the radiation beam such that the rear heating pulse includes a front portion having the rear heating power level, and a rear portion having a power level which is lower than the erase power level. 
     
     
         21 . A recording device for recording data in the form of marks on a recording medium, said recording medium comprising an information layer having a phase which is reversibly changeable between a crystal phase and an amorphous phase, and said marks having lengths of nT, where T represents the length of one period of a reference clock in a data signal and n represents a predetermined natural number larger than 1, by irradiating the information layer by a pulsed radiation beam, the recorded marks being erasable by irradiating the information layer with a radiation beam having an erase power level, the device comprising a radiation source providing the radiation beam and a control unit for controlling the power of the radiation beam, the control unit being operative for providing a sequence of write pulses for writing a mark and controlling the power of the radiation beam such that it has a cooling power level which is lower than the erase power level preceding a first write pulse of a sequence of pulses, wherein the recording device comprises means for determining a first value for the cooling power level when n=2, a second value for the cooling power level when n=3, and a third value for the cooling power level when n≧4, said first value for the cooling power level, said second value for the cooling power level and said third value for the cooling power level being dependent on properties of the radiation source. 
     
     
         22 . The recording device as claimed in  claim 21 , wherein the first value for the cooling power level is substantially equal to the second value for the cooling power level and the third value for the cooling power level. 
     
     
         23 . The recording medium for use in a recording device as claimed in  claim 13 , said recording medium comprising an information layer having a phase which is reversibly changeable between a crystal phase and an amorphous phase, and comprising an area containing recording parameters, wherein the area containing recording parameters comprises a value for the rear heating power level. 
     
     
         24 . The recording medium for use in a recording device as claimed in  claim 16 , said recording medium comprising an information layer having a phase which is reversibly changeable between a crystal phase and an amorphous phase, and comprising an area containing recording parameters, wherein the area containing recording parameters comprises a value for the front heating power level. 
     
     
         25 . The recording medium for use in a recording device as claimed in  claim 18 , said recording medium comprising an information layer having a phase which is reversibly changeable between a crystal phase and an amorphous phase, and comprising an area containing recording parameters, wherein the area containing recording parameters comprises a value for the cooling power level. 
     
     
         26 . The method of  claim 1 , further comprising providing a front heating pulse between the first write pulse and the cooling pulse, the front heating pulse having a front heating power level which is higher that a write power level of the first write pulse. 
     
     
         27 . The method of  claim 1 , wherein a further rear heating pulse having a further rear heating power level follows the rear heating pulse, the further rear heating power level being less than the erase power level. 
     
     
         28 . The method of  claim 1 , wherein the first write pulse is followed by a further cooling pulse having a further cooling power level, the further cooling power level being less than the cooling power level. 
     
     
         29 . A recording device for recording data in the form of marks on a recording medium, said recording medium comprising an information layer having a phase which is reversibly changeable between a crystal phase and an amorphous phase, and said marks having lengths of nT, where T represents the length of one period of a reference clock in a data signal and n represents a predetermined natural number larger than 1, by irradiating the information layer by a pulsed radiation beam, the recorded marks being erasable by irradiating the information layer with a radiation beam having an erase power level, the device comprising a radiation source configured to provide the radiation beam and a control unit configured to control the power of the radiation beam, the control unit being operative for providing a sequence of write pulses for writing a mark and controlling the power of the radiation beam for providing a cooling power level which is lower than the erase power level preceding a first write pulse of a sequence of pulses, wherein the control unit is further configured to determine a first value for the cooling power level when n=2, a second value for the cooling power level when n=3, and a third value for the cooling power level when n≧4, the first value for the cooling power level, the second value for the cooling power level and the third value for the cooling power level being different power levels. 
     
     
         30 . The recording device of  claim 29 , wherein the first value for the cooling power level, the second value for the cooling power level and the third value for the cooling power level are dependent on properties of at least one of the radiation source and the recording medium.