Information recording/reproducing unit and information...

Details Information recording/reproducing unit and information... Information recording/reproducing unit and information...

1998-02-18

2001-04-24

Beausoliel, Jr., Robert W. (Department: 2785)

Error detection/correction and fault detection/recovery

Data processing system error or fault handling

Reliability and availability

Reexamination Certificate

active

06223302

ABSTRACT:

THIS APPLICATION IS A U.S. NATIONAL PHASE APPLICATION OF PCT INTERNATIONAL APPLICATION PCT/JP96/02222.
FIELD OF THE INVENTION
The present invention relates to an information recording/reproducing unit, whereby recording and reproducing of data are performed, and a data medium for use in the foregoing recording and reproducing of data.
BACKGROUND OF THE INVENTION
An information recording/reproducing unit has so far been employing such a recording medium control system as described typically in the standards ISO10089, ISO10090 and ISO10091 for use with a magneto-optic disk, for example, whereby the recording area of a recording medium is broadly divided into three areas (user area, alternate area and data medium control area).
A user area is used for recording/reproducing the data required by higher level units. An alternate area is used as an alternate sector for alternate processing, wherein data are recorded, by substituting a defective sector in the user area. A data medium control area is used for recording/reproducing a defective list and alternate list to control the alternate processing.
When data is recorded in a user area of a recording medium, a determination is made on whether recording errors are generated or not, or whether data is correctly recorded or not, by a method of comparing signals obtained by reproducing immediately after recording the data with the data that was intended for recording, and the like for each respective sector, for example.
In general, recording errors are generated due to partial defects of a recording medium itself and a malfunction in the record system of a recording/reproducing unit.
When recording errors are found to have been generated, the previous data is again recorded in an alternate sector within an alternate area by substituting the defective sector of the user area wherein recording of data was made before, and at the same time defects control information that provides positional information on the defective sector and alternate sector is recorded in the data medium control information area.
How these user area, alternate area and data medium control information area are structured can be determined arbitrarily. For example, a track of data medium on the disk of an information recording/reproducing unit as shown in
FIG. 15
is defined as one of a plurality of paths formed on the data medium by the division thereof performed along the radius of the disk and each respective track of the above is divided along the direction of rotation into 16 segments, each being called a sector.
Assuming there are a data medium control information area, user data area and alternate area on the foregoing data medium, for example,
FIG. 12
shows how a structure is formed on the record medium.
Here,
601
indicates a first data medium control information area,
602
indicates a second data medium control information area,
603
indicates a user area,
604
indicates an alternate area,
605
indicates a third data medium control information area and
606
indicates a fourth data medium control information area. The data medium control information is formed of the user area
603
detected at the time of initialization of a recording medium
600
, primary defect lists (PDLs)
608
a
and
608
b
that keep the positional information on an alternate sector in the alternate area
604
, secondary defect lists (SDLs)
609
a
and
609
b
that indicate a defective sector detected at the time of data recording in the user area and the positional information on an alternate sector in the alternate area with data recorded by substituting the defective sector, and a disk definition structure (DDS)
607
that indicates the start of data medium control information, fixed start addresses of PDLs
608
a
and
608
b
and SDLs
609
a
and
609
b
and a data structure on the record medium (positional information on ROM data, RAM data and the like).
In other words, the data medium control information comprises DDS
607
, PDL
608
a
and
608
b
, and SDL
609
a
and
609
b
, and the similar data are recorded in each respective data medium control information area.
A RAM
612
is a memory wherein reproduced data medium control information is stored. The description that follows employs SDL
609
a
and
609
b
whereby data medium control information is updated when a defective sector is found.
The present example of prior art adopts a 2 sector state for both PDL and SDL.
When a recording medium
600
is loaded in a recording/reproducing unit for execution of data recording/reproducing, DDS
607
, PDL
608
a
and
608
b
, and SDL
609
a
and
609
b
are reproduced and then stored in a RAM
612
.
When data medium control information is changed, the SDL stored in the RAM
612
is recorded in each of the first to fourth data medium control information areas
601
,
602
,
605
and
606
on the recording medium, respectively. Accordingly, every time when a defective sector in the user area is detected, positional information on the defective sector, an alternate sector replacing the defective sector and the like is added to the RAM
612
, thereby updating the SDL in the RAM
612
.
The SDL after the foregoing updating is recorded in each of the first to fourth data medium control information areas
601
,
602
,
605
and
606
on the recording medium, respectively.
The SDL stored in the RAM
612
is recorded in each of the first to fourth data medium control information areas
601
,
602
,
605
and
606
on the recording medium
600
, respectively.
An example of the contents of these SDL
809
a
and
809
b
is shown in FIG.
14
(
a
), wherein the data unit of SDL is 1 byte, the reference numeral
800
shows a defect list identifier formed of 2 byte fixed data, the reference numeral
801
shows a reserved field held for future expansion, the reference numeral
802
shows the number of defective sectors held in the SDL, the reference numeral
803
is the address to show a location of a defective sector, the reference numeral
804
is the address to show a location of an alternate sector substituting the foregoing defective sector, and the reference
805
shows a blank field set aside for defective sectors that are detected in future.
Here, each respective positional information on a pair of defective sector and alternate sector is expressed by employing the data
803
and
804
formed of 8 bytes.
According to this SDL, it is understood that the number of defect cataloged is 1, the address (X1) is a defective sector and the address (Y1) is an alternate sector replacing the foregoing defective sector.
Thus, an inability to use data medium control information due to partial defects on a recording medium and the like has been prevented in the prior art by recording data medium control information in a plurality of data medium control information areas. However, when the data medium control information in RAM
612
is recorded on a recording medium
600
, the data of the RAM
612
are sometimes not updated correctly because of partial defects on the recording medium.
At this time, the data medium control information area is not allowed to read-in, resulting in a reduction of usable data medium control information areas by one.
Therefore, if there are any defective sectors, even only one, in the data medium control information area, the use of the data medium control information area becomes impossible.
More specifically, a problem was encountered in the past that the entire data medium could not be used due to the existence of 4 defective sectors.
With the alternate list and defect list in the prior art, recording locations are fixed as shown in FIG.
12
and assuming that the number of byte for 1 sector is 512 bytes and defective and alternate sectors as many as 63 are cataloged in SDL, for example, this SDL becomes 512 bytes, resulting in using up exactly 1 sector.
Further, when an address (X2) to be used as the next SDL happens to be a defective sector, a sector on a certain user area is a defective sector. Assuming that recording is executed on that sector which is a defective sector, a recor

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