Claims
- 1. A control method of controlling recording and reproducing of optical records in an optical magnetic disk apparatus using a mark length recording method, comprising the steps of:
- recording a predetermined test pattern on a recording medium;
- reproducing said predetermined test pattern;
- controlling at least one shift amount selected from a defocus amount of a laser beam on a recording medium, a position shift amount of a recording position on a track at which recording is performed on said recording medium and a power shift amount of laser power irradiated during recording, to reduce a distortion of the reproduced said predetermined test pattern to less than a first predetermined value;
- obtaining control information under various environments in which optical recording and reproducing are performed, by repeating said steps of recording, reproducing said predetermined test patterns and controlling;
- recording general data on said recording medium by setting an optimum pulse width or an optimum laser power for recording on a basis of said control information; and
- reproducing said general data by subjecting a reproduced said general data to wave-equalizing processing, to reduce a distortion of said general data reproduced to less than a second predetermined value which is less than said first predetermined value.
- 2. A control method according to claim 1 wherein, in said controlling step, a characteristic to be controlled when recording and reading of said predetermined test pattern are performed is said defocus amount of a laser beam on said recording medium during recording of said test pattern, and said defocus amount is adjusted to .+-.0.05 .mu.m or less.
- 3. A control method according to claim 1 wherein, in said controlling step, a characteristic to be controlled when recording and reading of said predetermined test pattern are performed is said position shift amount of a recording position on a track at which recording is done on said recording medium, and said position shift amount is adjusted to .+-.0.10 .mu.m or less.
- 4. A control method according to claim 1 wherein, in said controlling step, a characteristic to be controlled when recording and reading of said predetermined test pattern are performed is said power shift amount of laser power irradiated on said recording medium during recording, and said power shift amount is adjusted to .+-.0.20 mW or less.
- 5. A control method according to claim 1 wherein a system for providing information to an edge portion of an information recording pit is used as a system for recording said general data on said recording medium.
- 6. A control method according to claim 1 wherein for determination of said control information, a predetermined recording pattern is trially recorded in advance of recording, the recorded said predetermined recording pattern is reproduced, and a reproduced said predetermined recording pattern is compared with reference information stored in a predetermined table to determine said control information.
- 7. A control method according to claim 1 wherein a medium including a magnetic film having vertical magnetic anisotropy is used as said recording medium to perform recording in a direction of magnetization of said vertically magnetized film, and recorded information is reproduced by using a magneto-optical effect to thereby perform recording and reading, a shape of a magnetic domain to be formed in said recording medium being controlled to control a read-out signal waveform.
- 8. A control method according to claim 2, wherein said defocus amount is more specifically adjusted to .+-.0.30 .mu.m or less.
- 9. A control method according to claim 3, wherein said position shift amount is more specifically adjusted to .+-.0.80 .mu.m or less.
- 10. A control method according to claim 4, wherein said power shift amount is more specifically adjusted to .+-.0.10 mW or less.
Priority Claims (9)
Number |
Date |
Country |
Kind |
2-170052 |
Jun 1990 |
JPX |
|
2-256904 |
Sep 1990 |
JPX |
|
3-294145 |
Nov 1991 |
JPX |
|
4-026508 |
Feb 1992 |
JPX |
|
4-026509 |
Feb 1992 |
JPX |
|
4-026511 |
Feb 1992 |
JPX |
|
4-100897 |
Apr 1992 |
JPX |
|
4-186586 |
Jul 1992 |
JPX |
|
4-236969 |
Sep 1992 |
JPX |
|
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a continuation-in-part of U.S. patent application Ser. No. 07/720,706 filed on Jun. 25, 1991, U.S. patent application Ser. No. 07/764,922 filed on Sep. 24, 1991 which is a continuation-in-part of the U.S. patent application Ser. No. 07/720,706, filed on Jun. 25, 1991 and U.S. patent application based on Patent Cooperation Treaty Application No. PCT/JP92/01460 which is filed on Nov. 10, 1992 the contents of which are incorporated herein by reference.
US Referenced Citations (7)
Foreign Referenced Citations (1)
Number |
Date |
Country |
61-239441 |
Oct 1986 |
JPX |
Related Publications (1)
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Number |
Date |
Country |
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764922 |
Sep 1991 |
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Continuation in Parts (2)
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Number |
Date |
Country |
Parent |
720706 |
Jun 1991 |
|
Parent |
720706 |
Jun 1991 |
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