Adjusting method for recording condition and optical disc device
AssigneeHitachi Consumer Electronics Co., Ltd.
InventorsHiroyuki Minemura, Takahiro Kurokawa
Life of this patent
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Abstract
An optical disc device and an adjusting method for a recording condition for use with the optical disc device that records data into an optical disc medium by using codes whose shortest run length is 2T and reproduces the recorded data by using an adaptive equalizing procedure and a PRML procedure, wherein the recording condition is so adjusted that a reproduced signal with desired quality can be obtained, by using, as the adaptive equalizing procedure, a procedure in which a tap coefficient Cn is set to a value obtained by averaging values of a tap coefficient an renewed by a LMS method, located symmetrically with each other along the time axis.
Claims5
An adjusting method for a recording condition for use with an optical disc device that records data into an optical disc medium by using codes whose shortest run length is 2T and reproduces the recorded data by using an adaptive equalizing procedure and a PRML procedure, comprising:
- the adaptive equalizing procedure being a procedure in which a tap coefficient Cn is set to a value obtained by averaging values of a tap coefficient an renewed by a LMS method, located symmetrically with each other along the time axis;
- a step of generating a first binary bit array by binarizing the reproduced signal waveform reproduced from the optical disc medium in accordance with the PRML procedure;
- a step of generating a second binary bit array and a third binary bit array which are obtained by shifting a interested edge of the first binary bit array to the left and right, respectively;
- a step of generating first, second and third target signal waveforms corresponding to the first, second and third binary bit arrays, respectively;
- a step of generating a first value equivalent to a difference between a Euclidean distance between the second target signal waveform and the reproduced signal waveform and a Euclidean distance between the first target signal waveform and the reproduced signal waveform, and generating a second value equivalent to a difference between the Euclidean distance between the third target signal waveform and the reproduced signal waveform and the Euclidean distance between the first target signal waveform and the reproduced signal waveform;
- a step of calculating a shift evaluation value for evaluating the shift of the interested edge by using a difference between the first and second values;
- and
- a step of adjusting the recording condition by using the shift evaluation value for evaluating the shift of the interested edge.
An method for recording data on an optical disc medium comprising:
- a step of using, as an adaptive equalizing procedure, a procedure in which a tap coefficient Cn is set to a value obtained by averaging values of a tap coefficient an renewed by a LMS method, located symmetrically with each other along the time axis;
- a step of generating a first binary bit array by binarizing a reproduced signal waveform reproduced from an optical disc medium in accordance with a PRML procedure;
- a step of generating a second binary bit array and a third binary bit array which are obtained by shifting an interested edge of the first binary bit array to the left and right, respectively;
- a step of generating first, second and third target signal waveforms corresponding to the first, second and third binary bit arrays, respectively;
- a step of generating a first value equivalent to a difference between a Euclidean distance between the second target signal waveform and the reproduced signal waveform and a Euclidean distance between the first target signal waveform and the reproduced signal waveform, and generating a second value equivalent to a difference between the Euclidean distance between the third target signal waveform and the reproduced signal waveform and a Euclidean distance between the first target signal waveform and the reproduced signal waveform;
- a step of calculating a shift evaluation value for evaluating the shift of the interested edge by using a difference between the first and second values;
- and
- a step of adjusting the recording condition by using the shift evaluation value for evaluating the shift of the interested edge;
- wherein data is recorded using codes whose shortest run length is 2T, on the basis of the adjusted recording condition.
An optical disc device having the function of recording data into an optical disc medium by using codes whose shortest run length is 2T and reproducing the recorded data by using an adaptive equalizing procedure and a PRML procedure, comprising:
- the adaptive equalizing procedure being a procedure in which a tap coefficient Cn is set to a value obtained by averaging values of a tap coefficient an rendered by a LMS method, located symmetrically with each other along the time axis;
- means for generating a first binary bit array by binarizing the reproduced signal waveform reproduced from the optical disc medium in accordance with the PRML procedure;
- a means for generating a second binary bit array and a third binary bit array which are obtained by shifting the interested edge of the first binary bit array to the left and right, respectively,
- means for generating first, second and third target signal waveforms corresponding to the first, second and third binary bit arrays, respectively;
- means for generating a first value equivalent to a difference between a Euclidean distance between the second target signal waveform and the reproduced signal waveform and a Euclidean distance between the first target signal waveform and the reproduced signal waveform, and for generating a second value equivalent to a difference between the Euclidean distance between the third target signal waveform and the reproduced signal waveform and a Euclidean distance between the first target signal waveform and the reproduced signal waveform;
- and
- means for adjusting a recording condition for the optical disc medium by using a difference between the first and second values.
Dependencies are inferred from the claim text.