Apparatus for and method for recording data on a rewritable optical record carrier
View Patent ↗A recording device for recording data on a rewritable optical record carrier ( 11 ). The device comprises recording means ( 21, 22, 25 ) for forming marks on the record carrier during recording operations by irradiating the record carrier with a radiation beam ( 24 ), the marks representing the data. Further, the device comprises control means ( 20 ) for controlling the recording operations and beam control means ( 31 ) for controlling a write power of the radiation beam with reference to an optimum write power by changing the write power within a predetermined write power range around the optimum write power for subsequent write cycles, each of the write cycles comprising at least one recording operation. Variation of the write power improves the overwrite quality, in particular, in the management area, such as the file system area.
1. A recording apparatus for recording data on a rewritable optical record carrier, which apparatus comprises:
recording means for forming marks on the record carrier during recording operations by irradiating the record carrier with a radiation beam, the marks representing the data; and
control means for controlling the recording operations, the control means comprising:
optimum power control means for initially determining an optimum write power of the radiation beam prior to a first write cycle in dependence on characteristics of the record carrier; and
beam control means for controlling a write power of the radiation beam with reference to the initially determined optimum write power by changing the write power from the initially determined optimum write power to a randomly selected optimal or non-optimal value from a range around the initially determined optimum write power for said subsequent write cycles, each of the write cycles comprising at least one recording operation
wherein the beam control means are for changing the write power within the write power range of ±10% around the optimum write power.
2. A recording apparatus as claimed in claim 1 , wherein the optimum power control means are for monitoring formation of the marks during the recording operations and for adjusting the optimal write power in dependence on the monitoring.
3. A recording apparatus as claimed in claim 1 , wherein the beam control means are for determining the write power range in dependence on allowable values of at least one parameter describing quality of recorded data.
4. A recording apparatus as claimed in claim 1 , wherein the beam control means are for changing the write power by randomly selecting a value from the write power range.
5. A recording apparatus as claimed in claim 1 , wherein the beam control means are for changing the write power by selecting a value from a set of discrete values of the write power.
6. A recording apparatus as claimed in claim 1 , wherein the beam control means are for changing the write power stepwise within the write power range.
7. A recording apparatus as claimed in claim 1 , the data comprising user data and management data related to the user data, the record carrier comprising a program area for recording the user data and a management area for recording the management data, wherein the beam control means are for changing the write power only for recording the management data.
8. A recording apparatus as claimed in claim 1 , the data organized in information blocks and comprising at least one data file under a file system, the information blocks grouped into at least one error correction code block, the record carrier comprising addressable locations for recording the information blocks, wherein the beam control means are for changing the write power for the at least one recording operation comprising recording of at least one of the following:
the at least one data file;
the at least one error correction code block;
at least one of the information blocks.
9. A recording apparatus as claimed in claim 7 , the management area comprising a file system area for storing file system data related to the user data, wherein the beam control means are for changing the write power only for recording the file system data.
10. A method of recording data on a rewritable optical record carrier comprising steps of:
forming marks on the record carrier during recording operations by irradiating the record carrier with a radiation beam, the marks representing the data,
determining an initial optimum write power of the radiation beam prior to the first write cycle in dependence on characteristics of the record carrier, and
controlling a write power of the radiation beam with reference to the initially determined optimum write power by changing the write power from the initially determined optimum write power to randomly selected optimal and non-optimal write power values within a predetermined write power range around the initially determined optimum write power for said subsequent write cycles, each of the write cycles comprising at least one recording operation
wherein the write power range is ±10% around the optimum write power.
11. A method as claimed in claim 10 , comprising steps of:
monitoring formation of the marks during the recording operations, and
adjusting the optimal write power in dependence on the monitoring.
12. A method as claimed in claim 10 , comprising a step of determining the write power range in dependence on allowable values of at least one parameter describing quality of recorded data.
13. A method as claimed in claim 10 , comprising changing the write power by randomly selecting a value from the write power range.
14. A method as claimed in claim 10 , comprising changing the write power by selecting a value from a set of discrete values of the write power.
15. A method as claimed in claim 10 , comprising changing the write power stepwise within the write power range.
16. A method as claimed in claim 10 , the data comprising user data and management data related to the user data, the record carrier comprising a program area for recording the user data and a management area for recording the management data, the method comprising changing the write power only for recording the management data.
17. A method as claimed in claim 10 , the data organized in information blocks and comprising at least one data file under a file system, the information blocks grouped into at least one error correction code block, the record carrier comprising addressable locations for recording the information blocks, the method comprising changing the write power for the at least one recording operation comprising recording of at least one of the following:
the at least one data file;
the at least one error correction code block;
at least one of the information blocks.
18. A method as claimed in claim 16 , the management area comprising a file system area for storing file system data related to the user data, the method comprising changing the write power only for recording the file system data.
19. A computer program product in one or more non-transitory computer-readable storage media, comprising program code means that, when executed by a computer, causes the computer to perform actions of:
forming marks on the record carrier during recording operations by irradiating the record carrier with a radiation beam, the marks representing the data,
determining an optimum write power of the radiation beam in dependence on characteristics of the record carrier, and
controlling a write power of the radiation beam with reference to the initially determined optimum write power by changing the write power from the initially determined optimum write power to randomly selected optimal and non-optimal write power values within a predetermined write power range around the initially determined optimum write power for said subsequent write cycles, each of the write cycles comprising at least one recording operation
wherein the write power range is ±10% around the optimum write power.