Information recording method having successive data write and data verify operations

In an information recording method in repeatedly and alternately performing a write operation and a verifying operation on an information recording medium having a spiral track, the data processing sector unit amount is set in advance to be less by the latency necessary for the inter-track jump. Also, the processing data for the data recording operation and the verifying operation are set to an appropriate length, so that a desired processing time is obtained from the time after termination of the data reading out operation of the verifying operation to the time of commencement of the data recording operation in the write operation. It is thus possible to minimize the latency from the writing operation to the verifying operation and the latency from the verifying operation to the next writing operation.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to an information recording method for 
recording information by alternately and repeatedly carrying out a data 
recording operation and a verifying operation in the control of an 
information recording and reproducing apparatus employing a disk shaped 
information recording medium having a spiral track. 
2. Description of the Prior Art 
In an optical disk, normally an optically detectable guide track such as 
guide groove is provided to render the track density high. On the 
recording layer on the guide track a laser light concentrated to about 1 
.mu.m is irradiated to induce an optically detectable change such as 
boring or phase change to record information. The recording pitch or track 
pitch is very small, about 1 .mu.m, so that, depending on the 
manufacturing process or the operation environment of the optical disk, 
various kinds of defects, dust, flaws, etc. are formed giving rise to 
dropout of the reproduced signal. Accordingly, the error rate before error 
correction of the optical disk is about 10.sup.-4 to 10.sup.-6, which is 
extremely large in comparison with that of the magnetic disk being 
10.sup.-9 to 10.sup.-12, and a number of defective sectors are generated 
on the optical disk. 
Accordingly, in an optical disk unit, in order to assure reliability of 
data, a verifying operation is required to be performed after the data 
recording operation. In the verifying operation, an error detection is 
performed against the data read out in a sector unit. When an 
uncorrectable error has been detected, defect management is necessitated. 
If a data necessary for defect management recording is stored in an 
optical disk unit, the optical disk unit is allowed to perform defect 
management efficiently. 
Practically, however, the memory capacity contained by an optical disk unit 
is limited, and sometimes all the data cannot be stored. In such a case, 
the data to be recorded is divided into plural sections, and the recording 
operation and the verifying operation on the divided data re carried out 
alternately and repeatedly. 
Hereinafter, the data recording operation and the verifying operation to be 
carried out alternately and repeatedly in the conventional optical disk 
unit is explained with reference to the drawings. 
FIG. 5 is a block diagram showing an ordinary optical disk unit. Between an 
optical disk drive 51 and a host system 52 there is disposed an optical 
disk drive controller 58. An optical disk 59 having a spiral track is 
housed in the optical disk drive 51. The optical disk drive controller 58 
is constructed by a memory circuit 53, an interface circuit 54, a data 
modulation and demodulation circuit 55, an error detection and correction 
circuit 56, and a microcontroller 57. In the memory circuit 53, the 
control data necessitated by the microcontroller 57 and the recording and 
reproducing data are stored. The interface circuit 54 controls the data 
transfer between the hose system 52 and the optical disk drive controller 
58. The data modulation and demodulation circuit 55 performs modulation 
and demodulation of data. The error detection and correction circuit 56 
performs encoding and decoding of the error correction code. The 
microcontroller 57 controls the interface circuit 54, the data modulation 
and demodulation circuit 55, and the error detection and correction 
circuit 56. 
FIG. 6 shows a format diagram of the optical disk 59, in which a continuous 
spiral track starting from track T.sub.0 is equally divided into 18 
sectors from S.sub.0 to S.sub.17. 
FIG. 7 is a view to illustrate the operation in the conventional optical 
disk unit, showing the state where the data recording operation and the 
verifying operation are repeatedly carried out. In FIG. 7, a latency 
corresponding to 1 sector is represented by .tau..sub..tau.. The term 
"latency" denotes a rotational delay of a disk drive, i.e., the time 
needed for data to rotate under the recording and reproducing head once 
the head is in position over the appropriate track. 
Hereinafter, the 40-sector data writing operation for alternately and 
repeatedly performing the data recording operation and the verifying 
operation in the processing unit of the 1 track data mount is explained 
with reference to FIG. 7. Here, it is assumed that, of the seek operation 
to the starting sector for performing a verifying operation after the data 
recording operation, the time required for the inter-track jump operation 
corresponds to the 4-sector latency. Also, it is assumed that a latency 
corresponding to 3 sectors in total is required for performing the 
post-process of the verifying operation and the pre-processes for the next 
data recording operation. 
First, the processing 701 or the data recording operation for 18 sectors 
from sector S.sub.0 of track T.sub.1 to sector S.sub.17 of track T.sub.1 
is carried out. Then, in the processing 702, a seek operation of the data 
to be verified to the heat track T.sub.1 sector S.sub.0 is carried out. 
For the purpose of this seek operation, a latency corresponding to at 
least 4 sectors for the inter-track jump operation is required, and for 
the seek operation in the processing 702, a latency corresponding to 1 
track is required. 
Next, in the processing 703, the verifying operation for 18 sectors from 
the sector S.sub.0 of the track T.sub.1 to the sector S.sub.17 of the 
track T.sub.1 are carried out. The subsequent second time data recording 
operation is performed from the track T.sub.2 sector S.sub.0. However, as 
a latency corresponding to 3 sectors in total is required to perform the 
post-process of the verifying operation and the pre-processes for the next 
data recording operation, in the processing 704, a latency of 15 sectors 
is performed for the seek operation to the track T.sub.2 sector S.sub.0. 
Thereafter, the processing 705 for an 18 sector data recording operation, 
the processing 706 or latency for the seek operation, the processing 707 
for the 18 sector data verifying operation, and again the processing 708 
or latency for the seek operation, the processing 709 for the 4 sector 
data recording operation, the processing 710 or latency for the seek 
operation, and finally the processing 711 for a 4 sector data verifying 
operation are similarly repeated to complete the 40 sector data recording 
operation. 
FIG. 8 is a time chart for illustrating the detailed processing in the 
conventional optical disk unit. Using FIG. 8, the operation from the 
processing 701 to the processing 704 is described in more detail. 
The processing 701 for an 18 sector data recording operation is carried out 
as follows: The data transferred sector by sector from the host system 52 
are passed through the interface circuit 54 and stored in the memory 
circuit 53. Further, the error detection and correction circuit 56 adds an 
error correction code to the data in the memory circuit 53 in the encoding 
operation in the unit of 1 sector. Further, the encoded data is modulated 
in the data modulation and demodulation circuit 55 and sent to the optical 
disk drive 51, and written in the sector S.sub.0 of the track T.sub.1 on 
the optical disk 59. The data modulation and writing operations, the 
encoding operation in the next sector, and further the transfer of the 
data from the host system 52 in the next sector are performed in parallel 
with one another repeatedly. Further, at the time when the writing of the 
data of 18 sectors up to the sector S.sub.17 of the track T.sub.1 has been 
completed, the processing 701 or the data recording operation for the 
first 1 track is terminated. 
Next, the processing 702 for a seek operation is carried out. The optical 
disk drive controller 58 sends a seek operation command to the optical 
disk drive 51 so as to perform the processing 703 or verifying operation 
from the sector S.sub.0 of the track T.sub.1, since the track structure of 
the optical disk 59 is spiral. In the optical disk drive 51, the 
processing 702 or seek operation of the sector S.sub.0 to the track 
T.sub.1 is performed. However, at the time when the jump operation between 
the tracks for the seek operation has completed, the unillustrated 
recording and reproducing head of the optical disk drive 51 is not ready 
on the sector S.sub.0. For this reason, for the seek operation of the 
sector S.sub.0 to the track T.sub.1 in the processing 702, a latency 
corresponding to one cycle rotation of the optical disk 59 is required. 
Then, the processing 703 or verifying operation of the data of 18 sectors 
is performed. On completion of the seek operation of the processing 702, 
the data modulation and demodulation circuit 55 demodulates the data read 
out in the unit of 1 sector from the sector S.sub.0 of the track T.sub.1. 
Further, the error detection and correction circuit 56 checks for the 
existence of an uncorrectable error while decoding the demodulated data. 
The data decoding operation and the demodulation operation to the next 
sector are concurrently performed. If no error is detected, a verifying 
operation for the 18 sectors up to the sector S.sub.17 of the track 
T.sub.1 is performed. If an error is detected during the verifying 
operation, the processing 703 is discontinued, and a processing to 
substitute the sector in which the error has been detected for other 
sector is performed. 
Thereafter, the processing 704 or a latency for the seek operation is 
performed. The post-process in the verifying operation of processing 703, 
or the decoding operation of the sector S.sub.17 of the track T.sub.1, is 
completed when the head is located on the sector S.sub.0 of the track 
T.sub.2. However, in order to perform a data recording operation from the 
sector S.sub.0 of the track T.sub.2, when the head is located on the 
sector S.sub.16 of the track T.sub.1, data transfer of the sector S.sub.0 
of the track T.sub.2 must be performed as pre-processes of the data 
recording operation. Accordingly, for recording the data from the sector 
S.sub.0 of the track T.sub.0 in the processing 705, a latency 
corresponding to 15 sectors is required for the seek operation of the 
processing 704. 
However, in the abovementioned conventional embodiment, because of the seek 
operation necessitated for performing a verifying operation after the data 
recording operation, there arises a latency corresponding to one cycle 
rotation of a disk with the addition of a latency to the time required for 
the inter-track jump operation. Also, in the conventional embodiment as 
described above, because of the necessity to perform a post-process of the 
verifying operation and pre-processes of the data recording operation, it 
is not possible to perform the data recording operation from the recording 
sector immediately following the termination of the verifying operation, 
so that there arises a latency corresponding to 15 sectors during the time 
from the verifying operation to the succeeding data recording operation. 
As described above, there arises a latency between the data recording 
operation and the verifying operation, resulting in an elongation of the 
data processing time. 
SUMMARY OF THE INVENTION 
An object of the present invention is to minimize the latency for the seek 
operation which is necessary when repeatedly and alternately performing 
the data recording operation and the verifying operation on an information 
recording medium having a spiral track. Another object of the present 
invention is to minimize the latency necessitated before the commencement 
of the data recording operation following the verifying operation. 
In order to attain the above objects, the information recording method of 
the present invention is characterized in that a data processing sector 
unit amount (i.e. the number of sectors to be recorded in one write 
operation and verified in one verify operation) in the data recording 
operation and verifying operation is defined by the number of sectors 
obtained by subtracting the number of sectors to be recorded in the 
processing time for the inter-track jump operation necessitated to perform 
the next verifying operation after the data recording operation from the, 
the number, or a multiple number, of sectors of the track. 
Further, the information recording method of the present invention is 
characterized in that the data processing unit in the first data recording 
operation is the number of sectors obtained by subtracting the number of 
sectors to be recorded in the write-verify overhead time required to 
perform the operation necessary for transition from the data recording 
operation to the verifying operation from the number of sectors of the 
track, and the data processing unit in the verifying operation and the 
data recording operation in the second operation and thenceforth is the 
number of sectors obtained by subtracting the number of sectors to be 
recorded in the processing time for the post-process of the verifying 
operation and the pre-processes of the data recording operation 
necessitated during the time from the data writing operation in the 
verifying operation to the data reading out operation in the next data 
recording operation from the number of sectors on which the data recording 
was performed for the first time. 
In the present invention, by the method as described above, it is possible 
to minimize the time of the seek operation necessitated for performing the 
verifying operation after the data recording operation by setting the 
processing data lengths for the data recording operation and verifying 
operation so that a processing time for the inter-track jump operation 
necessary for transition from the data recording operation to the next 
verifying operation is formed in performing a data recording operation and 
a verifying operation alternately and in repetition. 
Also, in the present invention, it is possible to minimize a latency 
necessitated by the commencement of the next data recording operation 
after the verifying operation by setting the processing data lengths for 
the data processing operation and verifying operation so that a processing 
time for the post-process of the verifying operation and the pre-processes 
of the data recording operation is formed during the time from the time 
after completion of the data reading out operation in the verifying 
operation to the time of commencement of the data writing operation in the 
data recording operation. 
In the present invention, it becomes possible to minimize the latency 
between the two operations of the data recording operation and the 
verifying operation by adequately setting the processing data for the data 
recording operation and verifying operation by performing the above 
information recording and reproducing method. In this manner it is 
possible to realize efficient data processing.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Hereinafter, the first and second embodiments of the information recording 
method of the present invention will be explained. In this explanation, 
the block diagram of the optical disk unit of FIG. 5 as used in the 
explanation on the conventional embodiment and the format chart on the 
optical disk in FIG. 6 are employed. In FIG. 5, the block diagrams for the 
optical disk unit of the conventional embodiment and the information 
recording and reproducing apparatus of the present invention embodiment 
are identical, with only the content of the microcontroller 57 being 
different. In FIG. 6, the optical disk used in the conventional embodiment 
and the operation which is an information recording medium to be used in 
the embodiment of the present invention have the same format. 
The information recording method, which is the first embodiment of the 
present invention, is explained with reference to the drawings. The first 
embodiment is an information recording method for minimizing the latency 
for the seek operation which is necessitated for performing the verifying 
operation after the data recording operation. 
FIG. 1 is a view to illustrate the operation of the first embodiment of the 
information recording method of the present invention. FIG. 1 
schematically shows the processing procedures for the optical disk drive 
controller 58 to record data on the optical disk 59 and the position of 
the recording and reproducing head on the optical disk 59. In FIG. 1, the 
latency corresponding to 1 sector is represented by .tau..sub..tau.. 
In this embodiment, a 40K byte data recording operation on an optical disk 
in which 1 track is composed of 18 sectors is explained herebelow. In this 
embodiment, as the sector length is 1K bytes, data recording of 40 sectors 
is performed. 
The data processing amount in each successive data recording operation and 
verifying operation is obtained as follows: The time required for the 
intertrack jump operation (which is a jumping operation of two tracks) in 
the seek operation for searching the head sector for performing the 
verifying operation after the data recording operation is called a track 
jump time, which is deemed to correspond to the latency corresponding to 4 
sectors. Further, the time required for the processing necessary for 
shifting from the data recording operation to the verifying operation is 
called the write-verify overhead time, and the track jump time is assumed 
to be equal to the write-verify overhead time. 
Further, it is assumed that a memory having a capacity corresponding to 14 
sectors is used for the verifying operation in the memory circuit 53. 
The data processing amount in each associated data recording operation and 
verifying operation is 14 sectors which is obtained by subtracting 4 
sectors corresponding to the track jump time from the sector capacity of 1 
track. The succeeding verifying operation is commenced without latency in 
the range not exceeding 14 sectors corresponding to the capacity of the 
memory circuit 53. 
The specific, concrete processing procedures are explained according to 
FIG. 1. Here, it is assumed that before the start of the initial data 
recording operation the information recording and reproducing head is 
already positioned at the top of the sector in which the data are to be 
written, and the data recording and verifying are to be carried out from 
the sector S.sub.0 of the track T.sub.1. 
First, the data recording operation for 14 sectors from the sectors S.sub.0 
of the track T.sub.1 to the sector S.sub.13 of the track T.sub.1, i.e., 
the processing 101, is performed. Then, the seek operation to the head of 
the data to be verified, i.e., the processing 102 is performed. In the 
processing 102, the inter-track jump operation is completed within the 
track jump time which corresponds to the recording of the latency 
corresponding to 4 sectors. Immediately thereafter, the not illustrated 
recording and reproducing head is at the top of the sector S.sub.0 of the 
track T.sub.1, by which the seek operation of the processing 102 is 
completed. 
Next, in the processing 103, the verifying operation for 14 sectors from 
the sector S.sub.0 of the track T.sub.1 to the sector S.sub.13 of the 
track T.sub.1 is performed. As it is not possible to carry out a data 
recording operation from the time immediately after the verifying 
operation, after the latency corresponding to 15 sectors for the seek 
operation, i.e., the processing 104, the second data recording operation 
is carried out for the data of 14 sectors from the sector S.sub.14 of 
track T.sub.1 in the processing 105. 
Thereafter, the operations of processing 106 or the latency for the seek 
operation, processing 107 or the data verifying operation for 14 sectors, 
again processing 108 or the latency corresponding to 15 sectors, 
processing 109 or the data recording operation for 12 sectors, processing 
110 or the latency for the seek operation, and finally processing 111 or 
the data verifying operation for 12 sectors are carried out in a similar 
manner to complete the data recording operation for 40 sectors. 
As described above, according to this embodiment, in repeating alternately 
the data recording operation and the verifying operation, the seek 
operation to be necessitated for performing the verifying operation after 
the data recording operation can be carried out with a minimum latency. 
To describe in general the data processing amount in each associated data 
recording operation and verifying operation which is a point of this 
system, when the data processing amount is set to be the value lying 
within the memory capacity and obtained by subtracting the number of the 
sectors corresponding to the track jump time between the tracks from the 
total number of the sectors of the tracks, the latency for the seek 
operation can be minimized. 
The information recording method according to the second embodiment of the 
present invention is hereinafter explained with reference to the drawings. 
In the second embodiment, the data recording operation and verifying 
operation which are repeatedly and alternately performed are more 
efficiently carried out by minimizing the latency in the first embodiment 
necessary during the time from the verifying operation to the shift to the 
next data recording operation. 
FIG. 2 is a view to illustrate the operation of the second embodiment of 
the information recording method of the present invention. FIG. 2 
schematically shows the processing procedures for the optical disk drive 
controller 58 to record data on the optical disk 59 and the position of 
the recording and reproducing head on the optical disk 59. In FIG. 2, the 
latency corresponding to 1 sector is represented by .tau..sub..tau.. 
FIG. 3 is a detailed timing chart showing the sequence from the point of 
completion of the verifying operation to the point of the start of the 
data recording operation in the embodiment of the present invention. 
FIGS. 4(a)-(d) depict is a memory map showing the state in the memory 
circuit 53 in the embodiment of the present invention. FIGS. 4(a), (b), 
(c) and (d) show respectively the recorded data stored in the memory 
circuit 53 at the time t.sub.1, t.sub.2, t.sub.3 and t.sub.4 in FIG. 2. 
In the present embodiment, the data recording operation of 40 sectors onto 
the optical disk in which one track is constituted by 18 sectors is 
explained below. The sector length is 1K bytes. 
First, the data processing amount in each associated data recording 
operation and verifying operation is obtained as follows. 
The time required for the jump operation between the tracks in the seek 
operation for searching the starting sector to carry out a verifying 
operation after the data recording operation is called a track jump time, 
which corresponds to the latency corresponding to 4 sectors. Further, the 
time required for the processing which is necessary for transition from 
the data recording operation to the verifying operation is called a 
write-verify overhead time. This write-verify overhead time is assumed to 
be equal to the track jump time. 
Further, the time required for 1 sector decoding for the verifying 
operation, which is a post-process of the verifying operation, and the 
time required for 1 sector data transfer and 1 sector encoding, which are 
the preprocesses of the data recording operation, are integrally denoted 
the controller internal processing time, which corresponds to the latency 
corresponding to 3 sectors in total. Moreover, the time which is required 
for the processing from the time after completion of the data reading out 
operation in the verifying operation to the commencement of the data 
writing operation in the data recording operation is denoted a 
verify-write overhead time. This verify-write overhead time is to be equal 
to the controller internal processing time. 
In the memory circuit 53, a memory corresponding to a 14 sector capacity is 
to be used for verifying operation. 
The data processing unit in the first data recording operation is to be 14 
sectors after subtracting 4 sectors corresponding to the track jump time 
from the sector capacity of 1 track, so as to commence the succeeding 
verifying operation without latency within the range not exceeding 14 
sectors corresponding to the capacity of the memory circuit 53. Also, the 
data processing unit in the first verifying operation is to be 11 sectors 
after subtracting 3 sectors corresponding to the controller internal 
processing time from the processing unit of the data in the first data 
recording operation, so as to make the latency up to the data recording 
operation succeeding to the verifying operation a minimum. 
The data processing unit in the second data recording operation is to be 11 
sectors after subtracting the number of sectors corresponding to the track 
jump time and the controller internal processing time from the sector 
capacity of 1 track. The data processing unit in the second verifying 
operation is to be 11 sectors after subtracting the number of sectors 
corresponding to the controller internal processing time from the 14 
sectors in which the verifying operation has not yet been completed. The 
data processing unit in the third data recording operation and the data 
processing unit in the third verifying operation are also 11 sectors in 
entirely the same manner as in the second operations. 
Further, because the number of sectors in which the recording operation has 
not yet been completed is 4 sectors, which is less than the data 
processing amount in the second data recording operation, the data 
processing amount in the last data recording operation is to be the 
remaining 4 sectors. On completion of the recording operation for the last 
time, the verifying operation is performed on all of the 7 sectors on 
which the verifying operation has not yet been completed. 
Next, the concrete processing procedures are explained in accordance with 
FIG. 2. Here again, it is assumed that, before the commencement of the 
first data recording operation, the information recording and reproducing 
head is positioned at the top of the sector in which the data is to be 
written, and the data recording and verifying are to be performed from the 
sector S.sub.0 of the track T.sub.1. 
First, the data recording operation for 14 sectors from the sector S.sub.0 
of the track T.sub.1 to the sector S.sub.13 of the track T.sub.1, i.e., 
the processing 201, is performed. Then, the seek operation to the top of 
the data to be verified, i.e., the processing 202 is performed. In the 
processing 202, the inter-track jump operation is completed within the 
track jump time corresponding to the latency corresponding to 4 sectors. 
Immediately thereafter, the unillustrated recording and reproducing head 
is at the top of the sector S.sub.0 of the track T.sub.1, by which the 
seek operation of the processing 202 is completed. 
Next, in the processing 203, the verifying operation for the 11 sectors 
from the sector S.sub.0 of the track T.sub.1 to the sector S.sub.10 of the 
track T.sub.1 is performed. Further, in the processing 204, the second 
data recording operation is carried out for the data of the 11 sectors 
from the sector S.sub.14 of track T.sub.1. Thereafter, the operations of 
processing 205 or the latency for the seek operation, processing 206 or 
the data verifying operation for the 11 sectors, and processing 207 or the 
data recording operation for 11 sectors are performed. Further, processing 
208 or the latency for the seek operation, processing 209 or the data 
verifying operation for the 11 sectors, processing 210 or the data 
recording operation for the remaining 4 sectors, processing 211 or the 
latency for seek operation, and finally processing 212 or the data 
verifying operation for 7 sectors are repeated in a similar manner to 
complete the data recording operation for 40 sectors. 
Detailed operations of the processing 203 and the processing 204 are 
explained using FIG. 3. The first verifying operation of the processing 
203 is performed from the sector S.sub.0 of the track T.sub.1. The 
verifying operation is constituted by the two parallel operations of the 
processing 301, or the data reading out and demodulation operation per 1 
sector, and the processing 302, or the decoding operation of the read out 
data. The processing 204 or the second data recording operation is carried 
out from the sector S.sub.14 of track T.sub.1. This data recording 
operation is constituted by the processing 303 or the data transfer 
operation, the processing 304 or the encoding operation per 1 sector, and 
the processing 305 or the modulation and writing of the encoded data. The 
operations of processing 304 and processing 305 are carried out in 
parallel with each other. 
After completion of the processing 301 or data reading out and demodulation 
operation, 1 sector decoding operation, data transfer operation prior to 
the data modulation and writing operation, and 1 sector encoding operation 
are carried out within the latency corresponding to 3 sectors. Then, the 
processing 305 or data modulation and writing operation is carried out. In 
order to eliminate the latency from the time after completion of the 
verifying operation to the commencement of the data recording operation, 
the optical disk drive controller 58 carries out a verifying operation up 
to the sector S.sub.11 of the track T.sub.0, with 3 sectors corresponding 
to the controller internal processing time left in advance by the track 
T.sub.1 sector S.sub.14 at which the operation of the processing 305 
starts. In the processing 203, the data recording operation of 11 sectors 
is performed in this manner. 
In this data recording operation, storing of the recorded data in the 
memory circuit 53 is carried out as follows: The recorded data is first 
stored from the top of the memory circuit 53, and then sequentially stored 
from the data next to the data previously stored. The memory circuit 53 is 
used in a so-called round buffer type manner, so that, when the data to be 
housed comes to the last order, it stores the data from the head of the 
memory again. 
At the time t.sub.1 after termination of the operation of the processing 
201, as shown in FIG. 4(a), the data recorded in the processing 201 is 
stored from the top of the memory circuit 53. In the operation of the 
processing 204, at the time t.sub.2 when the operation of the processing 
204 is terminated, of the recorded data, the data of 14 sectors are not 
verified, and the state in the memory circuit 53 is as shown in FIG. 4(b). 
Even at the time t.sub.3 when the processing 207 has been terminated, the 
data of 14 sectors which have not yet been verified are stored in the 
memory circuit 53 as in FIG. 4(c). At the time t.sub.4 at which the 
processing 210 which is the last data recording operation is terminated, 
the non-verified data of 7 sectors are stored as in FIG. 4(d). 
In the above manner, the data recording in the second embodiment can be 
performed within the memory capacity corresponding to 14 sectors after 
subtracting 4 sectors corresponding to the track jump time from the sector 
capacity of 1 track. 
As described above, according to this embodiment, in repeating alternately 
the data recording operation and the verifying operation, the latency for 
the seek operation to the starting sector of the verifying operation after 
the data recording operation can be minimized, and information recording 
can be carried out in a small memory capacity. 
Lastly, the data processing sector amount in the data recording operation 
and verifying operation which is a point of this system is explained in 
generalized form. 
The data processing sector amount in the first data recording operation is 
set to be the value lying within the memory capacity and obtained by 
subtracting the number of the sectors corresponding to the track jump time 
between the tracks from the number of the sectors of the integer tracks, 
so as to minimize the latency for the seek operation. This value is called 
the recording sector unit amount. The data processing sector amount in the 
subsequent verifying operation is to be a value obtained after subtracting 
the number of sectors corresponding to the controller internal processing 
time from the recording sector unit amount so that the controller internal 
processing time is formed. This value is called a write-verify sector unit 
amount. 
The data processing sector amount in the second and subsequent data 
recording operations is to be a value obtained after subtracting the 
number of sectors corresponding to the track jump time and the controller 
internal processing time from the number of sectors corresponding to the 
same track number as that at the time of determining the initial recording 
sector number. This value becomes the same as the write-verify sector unit 
amount. The data processing unit in the second and subsequent verifying 
operation is to be a value obtained after subtracting the number of 
sectors corresponding to the controller internal processing time from the 
number of sectors which have not yet completed the verifying operation at 
the time of the commencement of the verifying operation. This value also 
becomes the same as the write-verify sector unit amount. 
In the second and subsequent data recording operations, when the remaining 
number of sectors to be recorded becomes equal or less than the number of 
the write-verify sectors, the remaining number of sectors to be recorded 
at that time is to be taken as the data processing sector unit amount in 
the final data recording operation. Also, the number of the sectors not 
verified at the termination of the data recording operation is to be taken 
as the data processing unit in the final verifying operation. 
In the present embodiment, the track jump time is taken as the time 
required for the inter-track jump operation in the seek operation for 
searching the starting sector which is carried out the verifying operation 
after the data recording operation. However, the present invention can be 
similarly applied by replacing this with the processing time of the 
operation necessitated during the time from after the data recording 
operation to the verifying operation. Further, in this embodiment the 
controller internal processing time is set to be the total of the time 
required for the pre-process of the verifying operation and the 
post-processes of the data recording operation. However, even by replacing 
this with the time required for the necessary processing from after the 
verifying operation to the next data recording operation, the present 
invention can be similarly applied. 
Further, in the present invention the invention is described only on the 
case where the information recording medium is an optical disk. However, 
the information recording and reproducing system of the present invention 
can be applied in entirely the same manner to the case of carrying out the 
data recording operation and the verifying operation alternately in 
repetition with an information recording medium having a spiral track 
structure other than optical disk.