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US 2010/0165805 A1Published application
Method and apparatus for determining an optimum power level
AssigneeKoninklijke Philips Electronics N.V.
InventorTony Petrus Van Endert
Life of this patent
Estimating the term…
Abstract
A fast optimum power control method is disclosed, with a laser power level being adjusted in a predetermined sequence at an ADIP/ATIP frame of an optical recording medium. Jitter is measured at each ADIP/ATIP frame in order to obtain an average jitter value for that particular frame, and hence power level.
Claims30
A method of determining an optimum power level for a laser device for writing to an optical storage medium, the method comprising the acts of:
- defining a test region of the optical storage medium;
- using a laser device having an operating output power level, writing a predetermined data pattern to the test region;
- measuring jitter values for the predetermined data pattern;
- and
- selecting an optimum operating output power level of the laser device for writing data to the optical storage medium depending upon the measured jitter values, the optimum power level minimizing the jitter value for the optical storage medium,
- wherein, during writing of the predetermined data pattern to the test region in a first scan of the medium, the operating output power level of the laser device is varied according to a first predetermined profile, and, during writing of the predetermined data pattern to the test region in a second scan of the medium, the operating output power level of the laser device is varied according to a second predetermined profile, the predetermined write power profile of the second scan being different from the predetermined write power profile of the first scan, whereby possible problems associated with non-homogeneities of the disc along its circumference are averaged out to reduce their effects.
3 more elements
A method of determining an optimum power level for a laser device for writing to an optical storage medium, the method comprising the acts of:
- defining a test region of the optical storage medium;
- using a laser device having an operating output power level, writing a predetermined data pattern to the test region;
- measuring jitter values for the predetermined data pattern;
- and
- selecting an optimum operating output power level of the laser device for writing data to the optical storage medium depending upon the measured jitter values, the optimum power level minimizing the jitter value for the optical storage medium,
- wherein, during writing of the predetermined data pattern to the test region in a first scan of the medium, the operating output power level of the laser device is varied according to a first predetermined profile, and, during writing of the predetermined data pattern to the test region in a second scan of the medium, the operating output power level of the laser device is varied according to a second predetermined profile, different from the first predetermined profile,
- wherein the predetermined profiles comprise a plurality of power level steps,
- wherein at least one jitter value is measured for each of the power level steps of the first and second predetermined profiles,
- wherein the step of selecting the optimum power level comprises:
- determining a function which relates jitter value to power level, over the range of power levels in the first and second predetermined profiles;
- and determining from said function an optimum power level that minimizes the jitter value,
- wherein the step of determining the function relating jitter value to power level comprises:
- for respective pairs of consecutive power levels, obtaining respective average power levels and respective average jitter values from the jitter values corresponding to those consecutive power levels;
- and
- determining a function which relates the average jitter values to the average power levels.
12 more elements
A method of determining an optimum power level for a laser device for writing to an optical storage medium, the method comprising the acts of:
- defining a test region of the optical storage medium;
- using a laser device having an operating output power level, writing a predetermined data pattern to the test region;
- measuring jitter values for the predetermined data pattern;
- and
- selecting an optimum operating output power level of the laser device for writing data to the optical storage medium depending upon the measured jitter values, the optimum power level minimizing the jitter value for the optical storage medium,
- wherein, during writing of the predetermined data pattern to the test region in a first scan of the medium, the operating output power level of the laser device is varied according to a first predetermined profile, and, during writing of the predetermined data pattern to the test region in a second scan of the medium, the operating output power level of the laser device is varied according to a second predetermined profile, different from the first predetermined profile,
- wherein the predetermined profiles comprise a plurality of power level steps,
- wherein at least one jitter value is measured for each of the power level steps of the first and second predetermined profiles,
- wherein the step of selecting the optimum power level comprises:
- determining a function which relates jitter value to power level, over the range of power levels in the first and second predetermined profiles;
- and determining from said function an optimum power level that minimizes the jitter value,
- wherein the step of determining the function relating jitter value to power level comprises:
- for respective triads of consecutive power levels, obtaining respective average power levels and respective average jitter values from the jitter values corresponding to those consecutive power levels;
- and
- determining a function which relates the average jitter values to the average power levels.
12 more elements
A method of determining an optimum power level for a laser device for writing to an optical storage medium, the method comprising the acts of:
- defining a test region of the optical storage medium;
- using a laser device having an operating output power level, writing a predetermined data pattern to the test region;
- measuring jitter values for the predetermined data pattern;
- and
- selecting an optimum operating output power level of the laser device for writing data to the optical storage medium depending upon the measured jitter values, the optimum power level minimizing the jitter value for the optical storage medium,
- wherein, during writing of the predetermined data pattern to the test region in a first scan of the medium, the operating output power level of the laser device is varied according to a first predetermined profile, and, during writing of the predetermined data pattern to the test region in a second scan of the medium, the operating output power level of the laser device is varied according to a second predetermined profile, different from the first predetermined profile,
- wherein the predetermined profiles comprise a plurality of power level steps,
- wherein at least one jitter value is measured for each of the power level steps of the first and second predetermined profiles,
- wherein the step of selecting the optimum power level comprises:
- determining a function which relates litter value to power level, over the range of power levels in the first and second predetermined profiles;
- and determining from said function an optimum power level that minimizes the litter value,
- wherein the step of determining the function relating jitter value to power level comprises:
- for respective pairs of consecutive power levels, obtaining respective average power levels and respective average jitter values from the jitter values corresponding to those consecutive power levels;
- for respective triads of consecutive power levels, obtaining respective average power levels and respective average jitter values from the jitter values corresponding to those consecutive power levels;
- and
- determining a function which relates the average jitter values to the average power levels.
13 more elements
Apparatus for determining an optimum power level for a laser device for writing to an optical storage medium, the apparatus comprising:
- means for defining a test region of the optical storage medium;
- a laser device having an operating output power level, operable to write a predetermined data pattern to the test region;
- means for measuring jitter values for the predetermined data pattern;
- and
- means selecting an optimum operating output power level of the laser device for writing data to the optical storage medium depending upon the measured jitter values, the optimum power level minimizing the jitter value for the optical storage medium,
- power adjustment means operable, during writing of the predetermined data pattern to the test region in a first scan of the medium, to vary the operating output power level of the laser device according to a first predetermined profile, and, during writing of the predetermined data pattern to the test region in a second scan of the medium, to vary the operating output power level of the laser device according to a second predetermined profile, the predetermined write power profile of the second scan being different from the predetermined write power profile of the first scan, whereby any possible problems associated with non-homogeneities of the disc along its circumference are averaged out to reduce their effects.
3 more elements
Apparatus for determining an optimum power level for a laser device for writing to an optical storage medium, the apparatus comprising:
- means for defining a test region of the optical storage medium;
- a laser device having an operating output power level, operable to write a predetermined data pattern to the test region;
- means for measuring jitter values for the predetermined data pattern;
- and
- means selecting an optimum operating output power level of the laser device for writing data to the optical storage medium depending upon the measured jitter values, the optimum power level minimizing the jitter value for the optical storage medium,
- power adjustment means operable, during writing of the predetermined data pattern to the test region in a first scan of the medium, to vary the operating output power level of the laser device according to a first predetermined profile, and, during writing of the predetermined data pattern to the test region in a second scan of the medium, to vary the operating output power level of the laser device according to a second predetermined profile, different from the first predetermined profile,
- wherein said means for selecting the optimum power level comprises:
- means for determining a function which relates jitter value to power level, over the range of power levels in the first and second predetermined profiles;
- and means for determining from said function an optimum power level that minimizes the jitter value,
- wherein said means for determining the function relating jitter value to power level comprises:
- means for obtaining, for respective pairs of consecutive power levels, respective average power levels and respective average jitter values from the jitter values corresponding to those consecutive power levels;
- and
- means for determining a function which relates the average jitter values to the average power levels.
10 more elements
Apparatus for determining an optimum power level for a laser device for writing to an optical storage medium, the apparatus comprising:
- means for defining a test region of the optical storage medium;
- a laser device having an operating output power level, operable to write a predetermined data pattern to the test region;
- means for measuring jitter values for the predetermined data pattern;
- and
- means selecting an optimum operating output power level of the laser device for writing data to the optical storage medium depending upon the measured jitter values, the optimum power level minimizing the jitter value for the optical storage medium,
- power adjustment means operable, during writing of the predetermined data pattern to the test region in a first scan of the medium, to vary the operating output power level of the laser device according to a first predetermined profile, and, during writing of the predetermined data pattern to the test region in a second scan of the medium, to vary the operating output power level of the laser device according to a second predetermined profile, different from the first predetermined profile,
- wherein said means for selecting the optimum power level comprises:
- means for determining a function which relates litter value to power level, over the range of power levels in the first and second predetermined profiles;
- and means for determining from said function an optimum power level that minimizes the jitter value,
- wherein said means for determining the function relating jitter value to power level comprises:
- means for obtaining, for respective triads of consecutive power levels, respective average power levels and respective average jitter values from the jitter values corresponding to those consecutive power levels;
- and
- means for determining a function which relates the average jitter values to the average power levels.
10 more elements
Apparatus for determining an optimum power level for a laser device for writing to an optical storage medium, the apparatus comprising:
- means for defining a test region of the optical storage medium;
- a laser device having an operating output power level, operable to write a predetermined data pattern to the test region;
- means for measuring litter values for the predetermined data pattern;
- and
- means selecting an optimum operating output power level of the laser device for writing data to the optical storage medium depending upon the measured litter values, the optimum power level minimizing the litter value for the optical storage medium,
- power adjustment means operable, during writing of the predetermined data pattern to the test region in a first scan of the medium, to vary the operating output power level of the laser device according to a first predetermined profile, and, during writing of the predetermined data pattern to the test region in a second scan of the medium, to vary the operating output power level of the laser device according to a second predetermined profile, different from the first predetermined profile
- wherein said means for selecting the optimum power level comprises:
- means for determining a function which relates jitter value to power level, over the range of power levels in the first and second predetermined profiles;
- and means for determining from said function an optimum power level that minimizes the jitter value,
- wherein said means for determining the function relating jitter value to power level comprises:
- means for obtaining, for respective pairs of consecutive power levels, respective average power levels and respective average jitter values from the jitter values corresponding to those consecutive power levels;
- means for obtaining, for respective triads of consecutive power levels, respective average power levels and respective average jitter values from the jitter values corresponding to those consecutive power levels;
- and
- means for determining a function which relates the average jitter values to the average power levels.
11 more elements
Recording apparatus for recording data to a disc, comprising an apparatus for determining an optimum power level, the apparatus comprising:
- means for defining a test region of the optical storage medium;
- a laser device having an operating output power level, operable to write a predetermined data pattern to the test region;
- means for measuring jitter values for the predetermined data pattern;
- and
- means selecting an optimum operating output power level of the laser device for writing data to the optical storage medium depending upon the measured jitter values, the optimum power level minimizing the jitter value for the optical storage medium,
- wherein power adjustment means operable, during writing of the predetermined data pattern to the test region in a first scan of the medium, to vary the operating output power level of the laser device according to a first predetermined profile, and, during writing of the predetermined data pattern to the test region in a second scan of the medium, to vary the operating output power level of the laser device according to a second predetermined profile, different from the first predetermined profile.
3 more elements
Dependencies are inferred from the claim text.