Dynamic information storage or retrieval – Binary pulse train information signal – Binary signal phase processing
Reexamination Certificate
2000-09-29
2001-08-28
Hindi, Nabil (Department: 2651)
Dynamic information storage or retrieval
Binary pulse train information signal
Binary signal phase processing
C369S047350, C369S059190, C369S047380
Reexamination Certificate
active
06282163
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to an optical disk recording/reproducing device capable of accurately reading address information from an optical disk in which address information indicative of a certain recording/reproducing position on the optical disk is repeatedly recorded several times.
BACKGROUND OF THE INVENTION
In an optical disk, address information is preformatted so that an optical disk recording/reproducing device can recognize recording/reproduction-use regions (sectors).
Various methods for preformatting the address information are available and known. Among such methods, a so-called address information multiple-recording method whereby an address information signal indicative of a certain sector is recorded several times is known as a preformatting method with which reproduction and establishment of address information can be improved.
In the case where address information is recorded only once upon random access to an optical disk, if reproduction of the same becomes impossible due to errors occurring to preformatted address information, the finding of a target sector becomes impossible, resulting in that information cannot be recorded/reproduced into/from the foregoing sector.
On the other hand, as described above, multiple recording of address information enables recording/reproduction of information in a sector even if an error occurs to a piece of address information indicative of the sector, since the sector can be recognized as long as another piece of the same address information can be reproduced.
Even with the multiple recording of address information as described above, it often takes place that address information cannot be accurately read by means of a conventional optical disk recording device.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an optical disk recording/reproducing device that is capable of obtaining precise phase information and generating a sampling clock subjected to phase control according to the phase information, with respect to an optical disk in which address information indicative of a certain recording/reproduction position is provided by multiple recording (or by a plurality of address patterns).
To achieve the foregoing object, an optical disk recording/reproducing device of the present invention is an optical disk recording/reproducing device that conducts at least one of recording, reproduction, or deletion of information data with respect to an optical disk in which address information indicative of a certain recording/reproduction position on an optical disk is recorded beforehand a plurality of times on an optical disk, and the device is characterized by comprising phase control means for adjusting phases thereof with respect to every address information, to optimize sampling timings for digitizing the address information thus recorded a plurality of times.
According to the foregoing arrangement, in reproduction of address information indicative of a certain recording/reproduction position in an optical disk in which the address information is provided by multiple recording, phase control is carried out with respect to each piece of the address information independently, in conducting the sampling. Therefore, even if an error occurs to one piece of the address information due to a certain cause, another piece of the address information can be precisely reproduced.
As the optical disk to which the present invention is applicable, an external-clock-type optical disk using clock marks can be used.
According to the present invention, reproduction by using a sampling clock subjected to precise phase control is enabled with respect to the external-clock-type optical disk using clock marks.
In the foregoing arrangement, the phase control means is preferably arranged so as to be provided for each piece of the address information independently, and each of said phase control means executes phase control using a reproduction signal of each piece of the address information.
The foregoing phase control means preferably includes (i) phase difference detecting means for detecting a phase difference between a digitized reproduction signal of the address information and a clock with a frequency equal to a bit cycle of the address information, (ii) leveling means for leveling outputs of said phase difference detecting means, (iii) timing generating means for outputting timings for each piece of the address information, (iv) holding means for holding an output of said leveling means at timings outputted by said timing generating means, and (v) clock phase control means for controlling a phase of a clock indicating sampling timings, according to an output of said holding means.
Furthermore, the foregoing phase difference detecting means preferably further includes (i) a both- edge detecting section for detecting edges of the digitized reproduction signal of each piece of the address information, so as to output an edge pulse, (ii) a rising edge detecting section for detecting rising of the clock, so as to output a rising edge pulse, and (iii) a phase difference holding section for holding a phase difference between the rising edge pulse of the clock and the edge pulse of the digitized reproduction signal of each piece of the address information.
Furthermore, in the foregoing arrangement, the phase difference holding means preferably includes (i) a counter for counting a time difference between a rising edge pulse of the clock and the edge pulse of the digitized reproduction signal of the address information, and (ii) a register for holding a value of said counter.
Furthermore, the foregoing leveling means preferably includes a moving average computing section for computing a moving average of the phase difference detected by said phase difference detecting means between the digitized reproduction signal of the address information and the clock.
Furthermore, the foregoing clock phase control means preferably includes (i) a shift register for generating a group of clocks obtained by delaying the clock by a predetermined unit, and (ii) a clock selector for selecting one clock providing timings closest to optimal sampling timings, from the group of clocks, and for outputting the selected one as a sampling clock.
Furthermore, the timing generating means is preferably arranged so as to include address identifying means for identifying an address information signal and error detecting means for detecting an error of the address information, and to output the timings when the address information signal is identified as a predetermined address information signal by said address identifying means and it is judged by said error detecting means that it includes no error.
Furthermore, the foregoing error detecting means is preferably arranged so as to detect an error detection code that is attached to the address information and is recorded on an optical disk beforehand, and based on a result of the detection, detects an error of the digitized reproduction signal of the address information.
To achieve aforementioned object, an optical disk recording/reproducing device of the present invention an optical disk recording/reproducing device that conducts at least one of the recording, reproduction, or deletion of information data with respect to an optical disk in which address information indicative of a certain recording/reproduction position on an optical disk is recorded beforehand on the optical disk a plurality of times by wobbling a side wall on one side of a recording track, and in which at least one clock mark is recorded with respect to each piece of the address information, and said device is characterized by comprising (1) clock mark detecting means for reproducing a clock mark based on a tangential push-pull signal, (2) address information detecting means for reproducing a plurality of pieces of the address information based on a radial push-pull signal, (3) clock generating means for generating a clock that has a phase conforming to that of the clock mark and that has a frequency equal to a b
Dike Bronstein Roberts & Cushman IP Group
Hartnell, III George W.
Hindi Nabil
Sharp Kabushiki Kaishi
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