Record carrier having a servo track with position information in accordance with a modulation type and permanent information in accordance with a different modulation type, and apparatus for scanning the record carrier

Abstract

A record carrier ( 1 ) has a servo track ( 4 ) indicating an information track ( 9 ) intended for recording information blocks. The servo track ( 4 ) has a periodic variation of a physical parameter at a predetermined frequency, usually called wobble. The servo track has modulated parts for encoding position information according to a predetermined type of modulation. The record carrier includes a management area in which the servo track includes permanent data. The permanent data is encoded using a different type of modulation, but using the variations of the same physical parameter. Direct digital modulation ( 41 ) is proposed for the different type of modulation.

The invention claimed is: 
     
       1. A record carrier comprising a servo track indicating an information track intended for recording information blocks represented by marks, said servo track having a periodic variation of a physical parameter at a predetermined frequency and modulated parts for encoding position information according to a predetermined type of modulation, characterized in that the record carrier further comprises a management area in which the servo track comprises permanent data represented by further variations of said physical parameter, the further variations being modulated in accordance with a type of modulation different from said predetermined type of modulation. 
     
     
       2. The record carrier as claimed in  claim 1 , wherein the predetermined type of modulation is a type of frequency or phase modulation of the periodic variation and/or the different type of modulation is direct digital modulation in which logical values of bits are represented by displacements of the servo track in a transverse direction. 
     
     
       3. The record carrier as claimed in  claim 2 , wherein the direct digital modulation is a run-length limited modulation (RLL). 
     
     
       4. The record carrier as claimed in  claim 1 , wherein the permanent data comprises key blocks for copy-protection and/or digital rights management. 
     
     
       5. The record carrier as claimed in  claim 1 , wherein the management area is not intended for recording information. 
     
     
       6. A record carrier comprising a servo track indicating an information track intended for recording information blocks represented by marks, said servo track having a periodic variation of a physical parameter at a predetermined frequency and modulated parts for encoding position information according to a predetermined type of modulation, characterized in that the record carrier further comprises a management area in which the servo track comprises permanent data represented by further variations of said physical parameter, the further variations being modulated in accordance with a type of modulation different from said predetermined type of modulation,
 wherein the management area has a track pitch between neighboring tracks larger than the track pitch in the area of the record carrier covered by the servo track indicating the information track intended for recording information blocks. 
 
     
     
       7. A recording and/or playback device comprising means for writing and/or reading information blocks in an information track on a record carrier having a servo track ( 4 ) indicating the information track ( 9 ), said recording and/or playback device comprises means for scanning the servo track, and demodulation means for retrieving position information from a signal generated by a variation of a physical parameter of the servo track at a predetermined frequency, said servo track having modulated parts for encoding position information according to a predetermined type of modulation, characterized in that the recording and/or playback device further comprises further demodulation means of a type different from said demodulation means for retrieving management data from a management area in which the servo track comprises the management data represented by further variations of said physical parameter, the further variations being modulated in accordance with the different type of modulation. 
     
     
       8. The recording and/or playback device as claimed in  claim 7 , wherein the demodulation means demodulates frequency or phase modulation of the periodic variation and/or the further demodulation means demodulates direct digital modulation in which logical values of bits are represented by displacements of the servo track in transverse direction. 
     
     
       9. The recording and/or playback device as claimed in  claim 7 , wherein the further demodulation means decodes run-length limited modulation (RLL). 
     
     
       10. A method of manufacturing a record carrier, in which the record carrier is provided with a servo track indicating an information track intended for recording information blocks, said servo track being provided with a variation of a physical parameter at a predetermined frequency and modulated parts for encoding position information according to a predetermined type of modulation, characterized in that the record carrier comprises a management area in which the servo track comprises management data represented by further variations of said physical parameter, the further variations being modulated in accordance with a type of modulation different from said predetermined type of modulation. 
     
     
       11. A record carrier comprising a servo track which has a periodic variation of a physical parameter at a predetermined frequency and modulated parts for encoding position information according to a predetermined type of modulation, and wherein the record carrier comprises a management area in which the servo track comprises permanent data represented by further variations of said physical parameter, the further variations being according to a different type of modulation, the different type of modulation providing a higher data rate than the predetermined type of modulation. 
     
     
       12. The record carrier as claimed in claim 11, wherein the predetermined type of modulation is a type of frequency or phase modulation of the periodic variation. 
     
     
       13. The record carrier as claimed in claim 11 or 12, wherein according to the different type of modulation a transition from one side to another represents a 1 and no transition represents a 0. 
     
     
       14. The record carrier as claimed in claim 11 or 12, wherein the different type of modulation is direct digital modulation in which logical values of bits are represented by displacements of the servo track in transverse direction. 
     
     
       15. The record carrier as claimed in claim 14, wherein the direct digital modulation is a run length limited modulation. 
     
     
       16. The record carrier as claimed in claim 11 or 12, wherein the permanent data comprises key blocks for copy-protection and/or digital rights management. 
     
     
       17. The record carrier as claimed in claim 11 or 12, wherein a recording area of the servo track indicates an information track for recording information blocks represented by marks, and the management area is outside the recording area for recording the informaLion blocks. 
     
     
       18. The record carrier as claimed in claim 11 or 12, wherein the management area has a track pitch between neighboring tracks larger than the track pitch in a recording area of the record carrier covered by the servo track indicating an information track for recording information blocks. 
     
     
       19. The record carrier as claimed in claim 14, wherein the permanent data comprises key blocks for copy-protection and/or digital rights management. 
     
     
       20. The record carrier as claimed in claim 14, comprising a recording area of the servo track wherein the servo track indicates an information track for recording information blocks represented by marks, and the management area is outside the recording area for recording information blocks. 
     
     
       21. The record carrier as claimed in claim 14, wherein the management area has a track pitch between neighboring tracks larger than the track pitch in a recording area of the record carrier covered by the servo track indicating an information track for recording information blocks. 
     
     
       22. The record carrier of claim 11, comprising a recording area with an information track indicated by the servo track, which information track is adapted for reading and/or recording information blocks represented by marks. 
     
     
       23. A recording and/or playback device comprising means for writing and/or reading information on a record carrier that comprises a servo track, which device comprises means for scanning the servo track and demodulation means for retrieving position information from a signal generated by a variation of a physical parameter of the servo track at a predetermined frequency, which servo track has modulated parts for the encoding position information according to a predetermined type of modulation, and wherein the device comprises further demodulation means of a different type for retrieving management data from a management area in which the servo track comprises the management data represented by further variations of said physical parameter, the further variations being according to the different type of modulation, the different type of modulation providing a higher data rate than the predetermined type of modulation. 
     
     
       24. The recording and/or playback device as claimed in claim 23, wherein the demodulation means are for demodulating frequency or phase modulation of the periodic variation. 
     
     
       25. The recording and/or playback device as claimed in claim 23 or 24, wherein the further demodulation means are adapted for demodulating the different type of modulation wherein a transition from one side to another represents a 1 and no transition represents a 0. 
     
     
       26. The recording and/or playback device as claimed in claim 23 or 24, wherein the further demodulation means are for demodulating direct digital modulation in which logical values of bits are represented by displacements of the servo track in transverse direction. 
     
     
       27. The recording and/or playback device as claimed in claim 26, wherein the further demodulation means are for decoding run length limited modulation. 
     
     
       28. The recording and/or playback device of claim 23, wherein the device is adapted for reading and/or writing information blocks in an information track in a recording area on the record carrier and the information track is indicated by the servo track on the record carrier. 
     
     
       29. A method of manufacturing a record carrier, in which the record carrier is provided with a servo track provided with a variation of a physical parameter at a predetermined frequency and modulated parts for encoding position information according to a predetermined type of modulation, and wherein the record carrier comprises a management area in which the servo track comprises management data represented by further variations of said physical parameter, the further variations being according to a different type of modulation, the different type of modulation providing a higher data rate than the predetermined type of modulation. 
     
     
       30. The method of manufacturing a record carrier of claim 29, in which the record carrier is provided with an information track for recording information blocks and wherein the information track is indicated by the servo track. 
     
     
       31. A record carrier comprising:
 an information track for recording information blocks represented by marks,   a servo track indicating the position of the information track and having a periodic variation of a physical parameter at a predetermined frequency and modulated parts encoded with position information according to a predetermined type of modulation,   a management area in which the servo track comprises management data represented by further variations of said physical parameter, the further variations being modulated in accordance with a type of modulation different from said predetermined type of modulation, the management data being different than the position information.   
     
     
       32. A recording and/or playback device comprising:
 means for scanning a record carrier for writing and/or reading information blocks represented by marks in an information track on a record carrier; and for reading a servo track on the record carrier, the servo track indicating the position of the information track and having modulated parts encoded with position information according to a predetermined type of modulation,   demodulation means for retrieving position information from a signal generated by a variation of a physical parameter of the servo track at a predetermined frequency,   further demodulation means, of a type different from said demodulation means, for retrieving management data from a management area of the servo track, the servo track of the management area comprising management data represented by further variations of said physical parameter, the further variations being modulated in accordance with the different type of modulation, the management data being different than the position information.   
     
     
       33. A method of manufacturing a record carrier, comprising:
 providing an information track for recording information blocks represented by marks on the record carrier,   providing a servo track on the record carrier, the servo track indicating the position of the information track and having a variation of a physical parameter at a predetermined frequency and modulated parts encoded with position information according to a predetermined type of modulation,   providing a management area in which the servo track comprises management data represented by further variations of said physical parameter, the further variations being modulated in accordance with a type of modulation different from said predetermined type of modulation, the management data being different than the position information.