Rotation control circuit based on the mean value of run length code generation patterns reproducing apparatus equipped with the rotation control circuit
First Claim
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1. A reproducing apparatus comprising:
- rotating means for rotating a disc-type recording medium;
data extracting means for extracting a run length limited code recorded on said disc-type recording medium;
reference inversion value generating means for generating a reference inversion value representative of an inversion probability pattern of the run length limited code recorded on said disc-type recording medium;
average inversion value detecting means for detecting the average inversion value of the run length limited code extracted from said data extracting means;
comparison means for comparing the reference inversion value from said reference inversion value generating means with the average inversion value from said average inversion value detecting means; and
control means for controlling said rotating means in accordance with the comparison result of said comparison means.
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Abstract
Disclosed are a rotation servo circuit and a reproducing apparatus equipped therewith. In the rotation servo circuit, the average value of an inversion probability pattern of a run length code recorded on a recording medium is calculated in advance and, on the basis of the average value thus obtained, a reference rotation voltage is generated, so that a rotation in accordance with the reference rotation voltage is effected whenever a reference number of revolutions is deviated from.
14 Citations
19 Claims
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1. A reproducing apparatus comprising:
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rotating means for rotating a disc-type recording medium; data extracting means for extracting a run length limited code recorded on said disc-type recording medium; reference inversion value generating means for generating a reference inversion value representative of an inversion probability pattern of the run length limited code recorded on said disc-type recording medium; average inversion value detecting means for detecting the average inversion value of the run length limited code extracted from said data extracting means; comparison means for comparing the reference inversion value from said reference inversion value generating means with the average inversion value from said average inversion value detecting means; and control means for controlling said rotating means in accordance with the comparison result of said comparison means. - View Dependent Claims (2, 3)
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4. A reproducing apparatus comprising:
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rotating means for rotating a disc-type recording medium; data extracting means for extracting a run length limited code recorded on said disc-type recording medium; reference inversion value generating means for generating a reference inversion value representative of an inversion probability pattern of the run length limited code recorded on said disc-type recording medium; average inversion value detecting means for detecting the average inversion value of the run length limited code extracted from said data extracting means; first comparison means for comparing the reference inversion value from said reference inversion value generating means with the average inversion value from said average inversion value detecting means and generating a first rotation servo signal on the basis of the comparison result; second comparison means for extracting a clock from the run length limited code extracted from said data extracting means, comparing the extracted clock with a predetermined reference clock, and generating a second rotation servo signal on the basis of the comparison result; and control means for controlling the supply of the first rotation servo signal and the second rotation servo signal to the rotating means. - View Dependent Claims (5, 6, 7, 8)
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9. A rotation servo circuit comprising:
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data extracting means for extracting an input run length limited code; reference inversion value generating means for generating a reference inversion value representative of an inversion probability pattern of the input run length limited code; average inversion value detecting means for detecting the average inversion value of the run length limited code extracted from said data extracting means; comparison means for comparing the reference inversion value from said reference inversion value generating means with the average inversion value from said average inversion value detecting means; and rotation drive signal generating means for generating a rotation drive signal on the basis of the comparison results of said comparison means. - View Dependent Claims (10, 11)
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12. A rotation servo circuit comprising:
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data extracting means for extracting an input run length limited code; reference inversion value generating means for generating a reference inversion value representative of an inversion probability pattern of the input run length limited code; average inversion value detecting means for detecting the average inversion value of the run length limited code extracted from said data extracting means; first comparison means for comparing the reference inversion value from said reference inversion value generating means with the average inversion value from said average inversion value detecting means and generating a first rotation servo signal on the basis of the comparison result; second comparison means for extracting a clock from the run length limited code extracted from said data extracting means;
comparing the extracted clock with a predetermined reference clock, and generating a second rotation servo signal on the basis of the comparison result. - View Dependent Claims (13, 14, 15)
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16. A reproducing apparatus comprising:
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a motor for rotating a disc-type recording medium; a data extractor for extracting a run length limited code recorded on said disc-type recording medium; a generator for generating a reference inversion value representative of an inversion probability pattern of the run length limited code recorded on said disc-type recording medium; a detector for detecting the average inversion value of the run length limited code extracted from said data extractor; a comparator for comparing the reference inversion value from said generator with the average inversion value from said detector; and a controller for controlling said rotating means in accordance with the comparison result of said comparator.
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17. A reproducing apparatus comprising:
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a motor for rotating a disc-type recording medium; an extractor for extracting a run length limited code recorded on said disc-type recording medium; a generator for generating a reference inversion value representative of an inversion probability pattern of the run length limited code recorded on said disc-type recording medium; an average inversion value detector for detecting the average inversion value of the run length limited code extracted from said extractor; a first comparator for comparing the reference inversion value from said generator with the average inversion value from said average inversion value detector and generating a first rotation servo signal on the basis of the comparison result; a second comparator for extracting a clock from the run length limited code extracted from said extractor, comparing the extracted clock with a predetermined reference clock and generating a second rotation servo signal on the basis of the comparison result; and a controller for controlling the supply of the first rotation servo signal and of the second rotation servo signal to the motor.
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18. A rotation servo circuit comprising:
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an extractor for extracting an input run length limited code; a generator for generating a reference inversion value representative of an inversion probability pattern of the input run length limited code; a detector for detecting the average inversion value of the run length limited code extracted from said extractor; a first comparator for comparing the reference inversion value from said generator with the average inversion value from said detector and generating a first rotation servo signal on the basis of the comparison result; second comparator for extracting a clock from the run length limited code extracted from said extractor, comparing the extracted clock with a predetermined reference clock and generating a second rotation servo signal on the basis of the comparison result.
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19. A rotation servo circuit comprising:
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an extractor for extracting an input run length limited code; a generator for generating a reference inversion value representative of an inversion probability pattern of the input run length limited code; a detector for detecting the average inversion value of the run length limited code extracted from said extractor; a comparator for comparing the reference inversion value from said generator with the average inversion value from said detector; and a rotation drive signal generator for generating a rotation drive signal on the basis of the comparison results of said comparator.
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Specification