Optical disk drive

Abstract

In an optical disk drive, running OPC (ROPC) is performed without fail, to thus enhance recording quality. ROPC is performed by use of a remaining portion of an area for APC operation within an APC area of a recording unit (RUB) in a next-generation optical disk such as a blu-ray disk. ROPC is performed by means of tentatively writing test data having a length of 50 T longer than a specified length of data to be recorded; and detecting level B of the amount of light reflected at that time. The APC area is formed from five wobble periods. APC is performed in periods of first two wobbles, and ROPC is performed in remaining three wobble periods.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred embodiment of the present invention will be described in detail by reference to the following figures, wherein:

FIG. 1 is an overall block diagram of an optical disk drive of an embodiment;

FIG. 2 is a block diagram of the principal section of the optical disk drive;

FIG. 3 is a descriptive view of a recording strategy;

FIG. 4 is a chart of timings at which APC and ROPC are performed;

FIGS. 5A to 5C are charts of timings at which ROPC is performed;

FIG. 6 is a graph showing a relationship between recording power and reflectance;

FIG. 7 is a graph showing a relationship between the radius of an optical disk and an ROPC proportion;

FIG. 8 is a descriptive view of a data structure of a blu-ray disk;

FIG. 9 is a block diagram of another principal section of the optical disk drive;

FIG. 10 is a descriptive view of a recording pulse signal by means of which test data are tentatively written;

FIGS. 11A to 11D are charts pertaining to timings of a waveform of a reproduced signal (the waveform of a sum signal) and timings of a detection waveform;

FIG. 12 is a graph showing a relationship between power and a β value;

FIG. 13 is another graph showing a relationship between power and the β value;

FIG. 14 is a graph of yet another principal section of the optical disk drive; and

FIG. 15 is a descriptive view of another data structure of the blu-ray disk.

Claims

1. An optical disk drive for recording data for each predetermined recording block, wherein the recording block includes a user data area;the optical disk drive includes irradiation means for radiating a recording laser beam; anda controller which radiates the recording laser beam in a predetermined area other than the user data area of the recording block, to thus tentatively write test data having a predetermined length, and which adjusts the power of the recording laser beam according to the amount of light reflected achieved during a period of tentative writing; andthe power of the recording laser beam is repeatedly adjusted for each predetermined recording block during data recording.

2. The optical disk drive according to claim 1, wherein a predetermined area other than the user data area is an APC area used for adjusting power.

3. The optical disk drive according to claim 2, wherein the controller tentatively writes the data having a predetermined length by use of a remaining portion of the area, in the APC area, which is used for computing a relationship between an electric current and the amount of light emission.

4. The optical disk drive according to claim 1, wherein the predetermined length is longer than a specified length of data to be recorded.

5. The optical disk drive according to claim 1, wherein a recording strategy for the test data is the same as a recording strategy for the data to be recorded.

6. The optical disk drive according to claim 1, wherein the controller adjusts the power of the recording laser beam according to a value of level B, which is the amount of light reflected at a timing when the amount of reflected light has become stable as a result of formation of pits, when the test data are tentatively data.

7. The optical disk drive according to claim 6, wherein the controller computes B/Pn (“n” is a real number of one or more) from the power P of a recording laser beam acquired when the test data are tentatively written and a value B of the level B, and adjusts the power of the recording laser beam according to B/Pn.

8. The optical disk drive according to claim 6, wherein the controller tentatively writes the test data, to thus change the power of the recording laser beam, and adjusts the power of the recording laser beam according to the value of the level B in the power of the recording laser beam.

9. The optical disk drive according to claim 3, wherein a proportion of the remaining area in the APC area is variably adjusted for each optical disk.

10. The optical disk drive according to claim 3, wherein a proportion of the remaining area in the APC area is variably adjusted according to a radial position on the optical disk.

11. An optical disk drive for recording data for each predetermined recording block, wherein the recording block includes a user data area;the optical disk drive includes irradiation means for radiating a recording laser beam; anda controller for adjusting recording power by means of interrupting data recording during recording of data; andthe controller tentatively writes test data by means of changing power in a predetermined area other than the user data area of the recording block when data recording is interrupted, and adjusts the power of the laser beam according to a relationship between the quality of a signal acquired by reproduction of the tentatively-written test data and power.

12. The optical disk drive according to claim 11, wherein the controller evaluates the quality of data recorded immediately before interruption, and adjusts the power of the laser beam according to the quality of the data recorded immediately before interruption as well as according to a relationship between the quality of a signal obtained as a result of reproduction of the tentatively-written test data and power.

13. The optical disk drive according to claim 11, wherein a predetermined area other than the user data area is a guard area subsequent to a run-out area.

14. The optical disk drive according to claim 13, wherein a predetermined area other than the user data area is an APC area which is provided in the guard area for adjusting power.

15. The optical disk drive according to claim 11, wherein the controller interrupts data recording at a point in time when data have been recorded to a predetermined length or only for a period of recording time.

16. The optical disk drive according to claim 11, wherein the controller interrupts data recording at a point in time when a predetermined amount of change in temperature has been detected.

17. The optical disk drive according to claim 11, wherein the controller interrupts data recording at a point in time when under-running of a buffer has been detected.

18. The optical disk drive according to claim 12, wherein the controller computes a relationship between the quality Q of a signal resulting from reproduction of the tentatively-written test data and power P of the signal as Q=f(P)+α serving as a predetermined offset, and computes the offset α by use of power Po and signal quality Qo of data which have been achieved immediately before interruption of data recording.

19. The optical disk drive according to 11, wherein a size of an area, in the APC area, where the test data are to be tentatively written is variably adjusted according to the type of an optical disk.

20. The optical disk drive according to 11, wherein a size of an area, in the APC area, where the test data are to be tentatively written is variably adjusted according to a radial position on an optical disk.