Dynamic information storage or retrieval – Control of storage or retrieval operation by a control... – By medium defect indicative control signal
Reexamination Certificate
1998-07-10
2001-08-28
Huber, Paul W. (Department: 2651)
Dynamic information storage or retrieval
Control of storage or retrieval operation by a control...
By medium defect indicative control signal
C369S053120, C369S053310
Reexamination Certificate
active
06282159
ABSTRACT:
TECHNICAL FIELD
The invention relates to a method and device for recording data on an optical memory card, and more particularly to a method and device for recording on an optical memory card, in that if a synchronization failure occurs while data is being recorded, data recording operation is stopped to prevent a recording capacity of the optical memory card from being degraded due to a recording error.
BACKGROUND ART
Generally, the optical memory card is a plastic card and can record and read data in its recording region with a laser beam.
FIG. 6
shows a recording region
102
of an optical memory card
101
. As shown in its enlarged diagram, data recording tracks
103
for recording information and guide tracks
104
formed at given intervals to control tracking for stabilizing a radiating position of the laser beams for recording and reading are alternately disposed on the recording region
102
.
The data recording tracks
103
and the guide tracks
104
have a different reflection ratio. The data recording tracks
103
have a reflection ratio higher than the guide tracks
104
do.
And, a record pit
105
is a portion having a low reflection ratio, which is formed in the data recording tracks
103
, with the laser beam when information is recorded. The presence or not of the record pit
105
indicates information recorded.
FIG. 7
shows a logical data structure of the recording region
102
. On the recording region
102
, in addition to a sector
120
where information is recorded, read-in
121
from which bit synchronization is obtained and an SYNC mark
122
from which frame synchronization is obtained by a non-illustrated optical memory card reader/writer when recording or reading and BOS
123
required for detecting a start position of the sector
120
are recorded.
The read-in
121
has the SYNC mark
122
recorded and record pits
105
formed at recorded intervals.
An optical memory card reader/writer (not shown) is provided with a synchronization signal generator (not shown), scans the optical memory card
101
at a scan rate so that a synchronization signal output from the synchronization signal generator agrees with a signal which rises for every one bit detected by scanning the read-in
121
, and keeps the same scan rate to have bit synchronization.
And, a modulation system which includes a synchronization signal into information to be recorded may be adopted to extract the synchronization signal from the signal detected when reading, in order to firmly retain the obtained bit synchronization.
The SYNC mark
122
is formed of record pits
105
, which are arranged in a pattern not produced by modulation, and used when the non-illustrated optical memory card reader/writer gets frame synchronization.
The frame is a bit separation to process a signal by a signal processing circuit in the non-illustrated optical memory card reader/writer. The non-illustrated optical memory card reader/writer is provided with a counter (not shown) for obtaining frame synchronization. The counter counts the synchronization signal, outputs a frame synchronization signal after counting up to the number of bits configuring one frame, and resets its counted number.
Since the SYNC mark
122
is recorded at the start end (or termination end) of the frame, the non-illustrated optical memory card reader/writer scans the optical memory card
101
. And when the SYNC mark
122
is detected, the number indicated by the non-illustrated counter for obtaining frame synchronization is reset, thereby assuring the acquisition of frame synchronization.
Description will be made of a procedure for recording data on the optical memory card.
A non-illustrated memory card reader/writer scans the optical memory card
101
to obtain bit synchronization by the read-in
121
and frame synchronization by the SYNC mark
122
. Then, the non-illustrated optical memory card reader/writer generates a write signal according to data to be recorded and enters the signal into a non-illustrated optical head. The optical head forms a record pit
105
on the data recording track
103
according to the write signal.
After recording all data, the non-illustrated optical memory card reader/writer reads the recorded data to compare it with data to be recorded. If they agree with each other, the recording operation is terminated, but if not, it is determined as recording error, and the recording operation is repeated from the beginning.
The recording error occurs frequently when synchronization between a card carrying velocity and an electric circuit (bit synchronization, frame synchronization) is lost due to interference such as vibrations on the non-illustrated optical memory card reader/writer during the recording operation.
FIG. 8
shows an example of the record pit
105
which is formed on the data recording track
103
if synchronization is lost.
In
FIG. 8
, a data recording track
103
-
1
has the record pits
105
formed normally, but a data recording track
103
-
2
has the record pits
105
formed with irregular intervals and some of them are overlaid with the SYNC marks
122
because synchronization was lost.
Data recorded on the data recording track
103
-
2
is not read normally. Therefore, it is rerecorded on another data recording track
103
.
However, the data recording method described above cannot rerecord data on the portion where a recording error has occurred, resulting in a disadvantage that the recording capacity of the optical memory card as the whole is lowered.
SUMMARY OF THE INVENTION
Under the circumstances as described above, it is an object of the invention to provide a data recording method and device for an optical memory card, which detects an occurrence of out-of-synchronization during recording operation and stops the recording operation to minimize a reduction in recording capacity due to a recording error.
To achieve the above object, the invention provides a data recording method for an optical memory card, which comprises detecting synchronization during data recording and stopping data recording and rerecording based on the detected result, wherein a synchronization signal, generated when a mark for detecting synchronization recorded on the optical memory card is detected, is compared with an internal synchronization signal which is generated by a data recording device, and according to the compared result, it is judged whether the synchronization is normal or not, and if the synchronization is abnormal, data recording is stopped.
If the synchronization detection mark cannot be detected, the judgment on whether the synchronization is normal or not is delayed until the synchronization detection mark is detected.
If the data recording is stopped, rerecording of the data is started from a frame adjacent to the frame where the data recording was stopped, based on a write cycle counted during the data recording.
The data recorded in the adjacent frame may be data which was being recorded into the frame where the data recording was stopped.
Also, the invention provides a data recording device for an optical memory card, which detects synchronization during data recording, stops data recording and rerecords based on the detected result, and comprises:
mark detecting means for detecting a mark for detecting synchronization recorded on the optical memory card;
synchronization signal generating means for generating a synchronization signal based on the mark for detecting synchronization detected by the mark detecting means;
internal synchronization signal generating means for generating an internal synchronization signal;
comparison means for comparing the synchronization signal generated by the synchronization signal generating means with the internal synchronization signal generated by the internal synchronization signal generating means to judge whether the synchronization is normal or not;
data recording stopping means for stopping the data recording according to the compared result obtained by the comparing means; and
rerecording start position deciding means for deciding a rerecording start po
Hogan & Hartson LLP
Huber Paul W.
Kabushiki Kaisha Nippon Conlux
LandOfFree
Data recording method and device for optical memory card... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Data recording method and device for optical memory card..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Data recording method and device for optical memory card... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2550498