Method and apparatus for performing beta prediction for high-speed writing on unknown recordable optical discs

Apparatus for predicting beta as a function of linear speed for CAV profiles, or disc radius for CAV writing, of an optical disc, for writing electronic data on said optical disc, the apparatus comprising:

• means for performing a plurality of test recordings of signals in an outer test zone (40) of said optical disc at a plurality of predetermined recording velocities, wherein the test recordings is expressed in terms of an outer test zone measured beta target value obtained from a read laser beam reflected back from the power of a writing laser beam;
• means for calculating at least one beta target values in a data zone (30) of said optical disc at a predetermined recording velocity, and using the at east one calculated beta target value and at least two outer test zone measured beta target values as input to a curve fitting method for predicting beta (power) as a function of linear speed for continuous angular velocity (CAV) speed profiles, or equivalently, as a function of disc radius for CAV writing, for high speed writing on said optical disc and
• means for predicting beta (power) as a function of linear speed for continuous angular velocity (CAV) speed profiles, or equivalently, as a function of disc radius for CAV writing, for high speed writing on said optical disc, for other linear speeds than the predetermined recording velocities, the predicting depending on the at least one calculated beta target value and the test recordings including test recording at least two different predetermined recording velocities.

A computer program product in one or more non-transitory computer-readable storage media, comprising program code means that, when executed by a computer, causes the computer to perform actions of:

• means for performing a plurality of test recordings of signals in an outer test zone (40) of said optical disc at a plurality of predetermined recording velocities, wherein the test recordings is expressed in terms of an outer test zone measured beta target value obtained from a read laser beam reflected back from the power of a writing laser beam;
• means for calculating at least one beta target values in a data zone (30) of said optical disc at a predetermined recording velocity, and using the at least one calculated beta target value and at least two outer test zone measured beta target values as input to a curve fitting method for predicting beta (power) as a function of linear speed for continuous angular velocity (CAV) speed profiles, or equivalently, as a function of disc radius for CAV writing, for high speed writing on said optical disc and
• means for predicting beta (power) as a function of linear speed for continuous angular velocity (CAV) speed profiles, or equivalently, as a function of disc radius for CAV writing, for high speed writing on said optical disc, for other linear speeds than the predetermined recording velocities, the predicting depending on the at least one calculated beta target value and the test recordings including test recording at least two different predetermined recording velocities.

A method for predicting beta as a function of linear speed for CAV profiles, or disc radius for CAV writing, for writing electronic data on an optical disc, comprising the steps of:

• (a) performing a plurality of test recordings of signals in an outer test zone (40) of said optical disc at a plurality of predetermined recording velocities, wherein the test recordings is expressed in terms of an outer test zone measured beta target value obtained from a read laser beam reflected back from the power of a writing laser beam;
• (b) calculating at least one beta target values in a data zone (30) of said optical disc at a predetermined recording velocity;
• and
• (c) predicting beta (power) as a function of linear speed for continuous angular velocity (CAV) speed profiles, or equivalently, as a function of disc radius for CAV writing, for high speed writing on said optical disc, for other linear speeds than the predetermined recording velocities, the predicting depending on the at least one calculated beta target value and the test recordings including test recordings at least two different predetermined recording velocities
• wherein said step (c) further comprises calculating the at least one beta target value inside said data zone (30) in accordance with the following equation:
• β
• ⁢
• ⁢
• t
• x
• =
• β
• ⁢
• ⁢
• t
• out
• ⁢
• ⁢
• _
• ⁢
• ⁢
• x
• +
• Δβ
• ·
• Ropc_out
• -
• R
• x
• Ropc_out
• -
• Ropc_in
• where Ropc—out and Ropc—in represent the radius of the outside and inside test areas of the optical disc, respectively, and
• where Δβ represents the difference between beta at the inside and outside disc radius at a certain speed.