Storing data on a medium in an optical system

• US 6,411,580 B1
• Filed: 10/12/2001
• Issued: 06/25/2002
• Est. Priority Date: 01/25/1993
• Status: Expired due to Fees

• Current Assignee: Noboru Kimura, Ronald G. Vitullo, Yasuhiro Yamazaki
• Original Assignee: Noboru Kimura, Ronald G. Vitullo, Yasuhiro Yamazaki
• Inventors: Yamazaki, Yasuhiro, Kimura, Noboru, Vitullo, Ronald G.
• Primary Examiner(s): Neyzari, Ali
• Application Number:
  US09/682,748
• Publication Number:
  US 20020041539A1
• Time in Patent Office: 256 Days
• Field of Search: 369/13.17, 369/275.3, 369/53.41, 369/275.2, 369/275.4, 369/47.1, 369/53.1, 369/59.1, 369/59.12, 369/59.14, 369/59.24, 369/116, 369/47.19, 369/53.22, 369/59.17, 369/59.21, 369/124.15, 369/59.16, 369/126, 369/44.25, 369/59.11, 369/59.19
• US Class Current: 369/59.17
• CPC Class Codes: G11B 11/10506 by modulating only the light beam of the transducer
• CPC Class Codes: G11B 11/10513 one of the light beam or the magnetic field being modulated by data and the other by a clock or frequency generator
• CPC Class Codes: G11B 11/10515 Reproducing compensating pit shift G11B11/1053
• CPC Class Codes: G11B 11/1053 to compensate for the magnetic domain drift or time shift
• CPC Class Codes: G11B 11/10597 Adaptations for transducing various formats on the same or different carriers
• CPC Class Codes: G11B 19/00 Driving, starting, stopping record carriers not specifically of filamentary or web form, or of supports therefor; Control thereof; Control of operating function ; Driving both disc and head
• CPC Class Codes: G11B 19/02 Control of operating function, e.g. switching from recording to reproducing
• CPC Class Codes: G11B 19/12 by sensing distinguishing features of or on records, e.g. diameter end mark
• CPC Class Codes: G11B 20/10 Digital recording or reproducing
• CPC Class Codes: G11B 20/10009 Improvement or modification of read or write signals
• CPC Class Codes: G11B 20/1258 where blocks are arranged within multiple radial zones, e.g. Zone Bit Recording or Constant Density Recording discs, MCAV discs, MCLV discs
• CPC Class Codes: G11B 20/1262 with more than one format/standard, e.g. conversion from CD-audio format to R-DAT format
• CPC Class Codes: G11B 20/1426 conversion to or from block codes or representations thereof
• CPC Class Codes: G11B 20/1833 by adding special lists or symbols to the coded information G11B20/1806, G11B20/1866 take precedence
• CPC Class Codes: G11B 2007/0006 adapted for scanning different types of carrier, e.g. CD & DVD
• CPC Class Codes: G11B 2020/1434 8 to 9 modulation
• CPC Class Codes: G11B 2220/2525 Magneto-optical [MO] discs
• CPC Class Codes: G11B 27/3027 used signal is digitally coded
• CPC Class Codes: G11B 7/0045 Recording G11B7/006, G11B7/0065 take precedence
• CPC Class Codes: G11B 7/00456 Recording strategies, e.g. pulse sequences G11B7/0062 takes precedence
• CPC Class Codes: G11B 7/005 : Reproducing G11B7/0065 takes precedence
• CPC Class Codes: G11B 7/0079 : Zoned data area, e.g. having different data structures or formats for the user data within data layer, Zone Constant Linear Velocity [ZCLV], Zone Constant Angular Velocity [ZCAV], carriers with RAM and ROM areas
• CPC Class Codes: G11B 7/013 : for discrete information, i.e. where each information unit is stored in a distinct discrete location , e.g. digital information formats within a data block or sector
• CPC Class Codes: G11B 7/126 : Circuits, methods or arrangements for laser control or stabilisation

Abstract

An encoder converts a binary data word to a binary code word. The encoded bits have first and second binary values at a predetermined clock interval. A pulse generator responds to the encoded bits to generate energizing pulses during each clock interval in which the encoded bits have the first binary value. The energizing pules have a uniform duration less than the clock interval. A laser responds to the energizing pulses for recording on a medium.

Claims

1. An apparatus comprising:

an encoder for converting a binary data word to a binary code word in which encoded bits have first and second binary values at a predefined clock interval;

a pulse generator responsive to the encoded bits so that energizing pulses having a uniform duration less than the clock interval are generated during each clock interval in which the encoded bits have the first binary value; and

a laser responsive to the energizing pulses for recording on a medium.

2. The apparatus of claim 1 further comprising magnetic flux means for applying a magnetic flux to the medium during recording.

3. The apparatus of claim 1, further comprising a data monitor receiving as input the encoded bits and detecting an occurrence of a set of encoded bit pattern.

4. The apparatus of claim 3 further comprising:

a write compensation circuit capable of shifting selected energizing pulses earlier in time in response to the detection of the encoded bit pattern.

5. The apparatus of claim 4 wherein encoded bit pattern in the set includes a pattern of two consecutive encoded bits having the second binary value.

6. The apparatus of claim 5 wherein the first binary value corresponds to a 1 and the second binary value corresponds to a 0, and the set of encoded bit pattern comprises one of 1100, 10100, and 00100.

7. The apparatus of claim 4 wherein the selected energizing pulses are shifted in a time interval earlier in time.

8. The apparatus of claim 7 wherein the time interval is approximately 4 to 6 or 8 to 12 nanoseconds.

9. The apparatus of claim 4 wherein the selected energizing pulses are shifted earlier in time by delaying all non-selected energizing pulses.

10. The apparatus of claim 1 further comprising;

a data monitor receiving as an input the encoded bits and detecting an occurrence of an encoded bit pattern indicative of a low frequency component and capable of extending at least one of the energizing pulses in response thereto.

11. The apparatus of claim 10 wherein the first binary value corresponds to a 1 bit, and the second binary value corresponds to a 0 bit, and wherein the encoded bit pattern comprises 000111.

23. An optical disk system including the apparatus recited in claim 1 for recording data on the medium.

12. An apparatus comprising:

an encoder for converting a binary data word to a binary code word in which encoded bits have first and second binary values at a predefined clock interval;

a pulse generator responsive to the encoded bits for generating energizing pulses during each clock interval in which the encoded bits have the first binary value;

a first data monitor receiving as an input the encoded bits and detecting the occurrence of any one of a first set of encoded bit patterns indicative of a low frequency component and capable of extending at least one of the energizing pulses in response thereto; and

a laser responsive to the energizing pulses for recording on the optical medium.

13. The apparatus of claim 12 wherein the first binary value corresponds to a 1 bit, and the second binary value corresponds to a 0 bit.

14. The apparatus of claim 12 wherein the first set of encoded bit patterns comprises 000111.

15. The apparatus of claim 12 further comprising a second data monitor receiving as input the encoded bits and detecting an occurrence of a second set of encoded bit pattern.

16. The apparatus of claim 15 further comprising a write compensation circuit capable of shifting selected energizing pulses earlier in time in response to an output of the second data monitor.

17. The apparatus of claim 16 wherein the encoded bit pattern in the second set includes a pattern of two consecutive encoded bits having the second binary value.

18. The apparatus of claim 16 wherein the first binary value corresponds to a 1 and the second binary value corresponds to a 0, and the second set of encoded bit pattern includes one of 1100, 10100, and 00100.

19. The apparatus of claim 16 wherein the selected energizing pulses are shifted in a time interval earlier in time.

20. The apparatus of claim 19 wherein the time interval is approximately 4 to 6 or approximately 8 to 12 nanoseconds.

21. The apparatus of claim 16 wherein the selected energizing pulses are shifted earlier in time by delaying all non-selected energizing pulses.

22. The apparatus of claim 15 wherein the first binary value corresponds to a 1 bit, and the second binary value corresponds to a 0 bit, and wherein the first set of encoded bit pattern comprises 000111.

24. A method, comprising:

converting binary data words to binary code words in which encoded bits have first and second binary values at a predefined clock interval;

generating energizing pulses during each clock interval in which an encoded bit has the first binary value;

monitoring the encoded bits to detect an occurrence of a first set of encoded bit pattern indicative of a low frequency component and extending a duration of at least one of the energizing pulses in response thereto; and

turning a laser on and off in response to the energizing pulses for recording on a medium.

25. The method of claim 24, wherein generating energizing pulses generates energizing pulses having a uniform duration less than the clock interval.

26. The method of claim 24 further comprising applying a magnetic field to the medium during recording.

27. The method of claim 24 wherein the first binary value corresponds to a 1 bit, and the second binary value corresponds to a 0 bit, and wherein the first set of encoded bit pattern comprises 000111.

28. The method of claim 24, further comprising:

detecting the occurrence of a second set of encoded bit pattern; and

shifting selected energizing pulses earlier in time in response to the detection of the second set of encoded bit pattern.

29. The method of claim 28 wherein the second set of encoded bit pattern includes a pattern of two consecutive encoded bits having the second binary value.

30. The method of claim 28 wherein the first binary value corresponds to a 1 and the second binary value corresponds to a 0, and the second set of encoded bit pattern comprises one of 1100, 10100, and 00100.

31. The method of claim 28 wherein the,selected energizing pulses are shifted in a time interval earlier in time.

32. The method of claim 31 wherein the time interval is approximately 4 to 6 or approximately 8 to 12 nanoseconds.

33. The method of claim 28 wherein the selected energizing pulses are shifted earlier in time by delaying all non-selected energizing pulses.

34. The method of claim 28 wherein the first binary value corresponds to a 1 bit, and the second binary value corresponds to a 0 bit, and wherein the first set of encoded bit pattern comprises 000111.

35. A disk made in accordance with the method of claim 24.

36. A apparatus comprising:

means for converting binary data words to binary code words in which encoded bits have first and second binary values at a predefined clock interval;

means for generating energizing pulses during each clock interval in which an encoded bit has the first binary value;

means for monitoring the encoded bits to detect an occurrence of any one of a first set of encoded bit patterns indicative of a low frequency component and extending a duration of at least one of the energizing pulses in response thereto; and

means for turning a laser on and off in response to the energizing pulses for recording on a medium.

37. The apparatus of claim 36, further comprising means for applying a magnetic field to the medium during recording.

38. The apparatus of claim 36 wherein the first binary value corresponds to a 1 bit, and the second binary value corresponds to a 0 bit, and wherein the first set of encoded bit pattern comprises 000111.

39. The apparatus of claim 36 further comprising:

means for detecting an occurrence of a second set of encoded bit pattern; and

means for shifting selected energizing pulses earlier in time in response to the detection of the second set of encoded bit pattern.

40. The apparatus of claim 39 wherein the second set of encoded bit pattern includes a pattern of two consecutive encoded bits having the second binary value.

41. The apparatus of claim 39 wherein the first binary value corresponds to a 1 and the second binary value corresponds to a 0, and the second set of encoded bit pattern comprises one of 1100, 10100, and 00100.

42. The apparatus of claim 39 wherein the selected energizing pulses are shifted in a time interval earlier in time.

43. The apparatus of claim 42 wherein the time interval is approximately 4 to 6 or approximately 8 to 12 nanoseconds.

44. The apparatus of claim 39 wherein the selected energizing pulses are shifted earlier in time by delaying all non-selected energizing pulses.

45. The apparatus of claim 39 wherein the first binary value corresponds to a 1 bit, and the second binary value corresponds to a 0 bit, and wherein the first set of encoded bit pattern comprises 000111.

46. An optical disk system including the apparatus recited in claim 36 for recording data on the medium.

47. An apparatus comprising:

encoder means for converting binary data words to binary code words in which encoded bits have first and second binary values at a predefined clock interval;

pulse generator means responsive to the encoded bits so that energizing pulses having a uniform duration less than the clock interval are generated during each clock interval in which the encoded bits have the first binary value; and

a laser responsive to the energizing pulses for recording on the optical medium.

48. The apparatus of claim 47, further comprising magnetic flux means for applying a magnetic flux to the optical medium during recording.

49. The apparatus of claim 47, further comprising:

data monitor means for receiving as input the encoded bits and detecting an occurrence of a set of encoded bit pattern; and

write compensation circuit means capable of shifting selected energizing pulses earlier in time in response to the detection of the encoded bit pattern.

50. The apparatus of claim 49 wherein the encoded bit pattern in the set includes a pattern of two consecutive encoded bits having the second binary value.

51. The apparatus of claim 50 wherein the first binary value corresponds to a 1 and the second binary value corresponds to a 0, and the set of encoded bit pattern comprises one of 1100, 10100, and 00100.

52. The apparatus of claim 49 wherein the selected energizing pulses are shifted in a time interval earlier in time.

53. The apparatus of claim 52 wherein the time interval is approximately 4 to 6 or approximately 8 to 12 nanoseconds.

54. The apparatus of claim 49 wherein the selected energizing pulses are shifted earlier in time by delaying all non-selected energizing pulses.

55. The apparatus of claim 47, further comprising;

data monitor means for receiving as an input the encoded bits and detecting an occurrence of an encoded bit pattern indicative of a low frequency component and capable of extending at least one of the energizing pulses in response thereto.

56. The apparatus of claim 55 wherein the first binary value corresponds to a 1 bit, and the second binary value corresponds to a 0 bit, and wherein the encoded bit pattern comprises 00011.

57. A method comprising the steps of:

directing a read beam at a recorded surface of the disk such that the read beam selectively accesses one of a plurality of tracks on the recorded surface;

detecting from a modulated beam returning from the recorded surface, the data recorded on the disk;

generating from the data recorded on the disk a clock signal that defines a clock interval equal to a time duration between bits of data recorded on the disk during a window substantially equal to the clock interval; and

pulse shaping by narrowing the width and increasing the amplitude of pulses of the binary signal by differentiating the binary signal, equalizing the differentiated signal, generating a first derivative of the equalized signal, and summing the equalized signal with the first derivative, thereby generating an improved binary signal; and

adjusting the threshold of sensitivity applied in the detecting step in response to the results of the pulse shaping.