U.S. patent application number 10/066664 was filed with the patent office on 2002-08-08 for method of overwriting data in a multi-session disk.
Invention is credited to Lee, Myung Kuk.
Application Number | 20020105863 10/066664 |
Document ID | / |
Family ID | 19705404 |
Filed Date | 2002-08-08 |
United States Patent
Application |
20020105863 |
Kind Code |
A1 |
Lee, Myung Kuk |
August 8, 2002 |
Method of overwriting data in a multi-session disk
Abstract
The present invention relates to a method of selectively
overwriting data written in a multi-session disk. To selectively
overwrite a session or sessions in a multi-session disk, this
method checks the size of new data requested to be written,
searches the multi-session disk for a single or a plurality of
consecutive sessions whose total size is larger than the size of
the new data, overwrites the single or the plurality of consecutive
sessions discovered in the searching step with the new data, and
updates temporary management information for tracks recorded in the
multi-session disk to reflect the overwritten session or sessions
in the temporary management information. Accordingly, one or more
sessions having useless data can be selectively overwritten without
affecting other sessions having important data, and storage
efficiency of a rewritable disk can be improved. Furthermore,
because track information in PMA exactly reflects real recorded
tracks after the session selective overwriting, a location error
never occurs when appending or reproducing data.
Inventors: |
Lee, Myung Kuk; (Kynggi-do,
KR) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Family ID: |
19705404 |
Appl. No.: |
10/066664 |
Filed: |
February 6, 2002 |
Current U.S.
Class: |
369/30.05 ;
369/53.24; 369/59.25; G9B/27.013; G9B/27.05 |
Current CPC
Class: |
G11B 2220/2545 20130101;
G11B 2220/216 20130101; G11B 27/036 20130101; G11B 27/034 20130101;
G11B 2220/218 20130101; G11B 20/1258 20130101; G11B 27/329
20130101 |
Class at
Publication: |
369/30.05 ;
369/53.24; 369/59.25 |
International
Class: |
G11B 007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 6, 2001 |
KR |
01-05733 |
Claims
What is claimed is:
1. A method of overwriting data in a multi-session disk, comprising
the steps of: (a) checking the size of new data requested to be
written; (b) searching the multi-session disk for a session whose
size is larger than the size of the new data; (c) overwriting the
session discovered in said step (b) with the new data; and (d)
updating temporary management information for tracks recorded in
the multi-session disk to reflect the overwritten session in the
temporary management information.
2. The method set forth in claim 1, wherein said step (b) adds up
each size of tracks included in a session, and selects the session
if the added-up size is larger than the size of the new data.
3. The method set forth in claim 1, wherein said step (b) adds up
each size of files included in a session, each file size having
been written in file system information recorded at the head of
each track of the session, and selects the session if the added-up
size is larger than the size of the new data.
4. The method set forth in claim 1, wherein said step (c) pads a
remaining area not overwritten in the session with null data.
5. The method set forth in claim 1, wherein said step (d) replaces
the temporary management information about tracks having been
included in the overwritten session with temporary management
information about the new track, and moves the temporary management
information about tracks in next sessions following the overwritten
session to a location right after the temporary management
information about the new track.
6. The method set forth in claim 5, wherein each track index number
written in the moved temporary management information is changed
appropriately to its track order.
7. The method set forth in claim 1, wherein said step (c) conducts
the overwriting operation after confirming an overwriting request
from a user.
8. The method set forth in claim 1, wherein said step (c) conducts
the overwriting operation for a session selected by a user if the
number of the sessions discovered in said step (b) is equal to or
greater than two.
9. The method set forth in claim 1, wherein said step (b) provides
a user with file information on all files included in a session, if
discovered, whose size is larger than the size of the new data.
10. The method set forth in claim 1, further comprising the step of
updating lead-in information of the overwritten session with
information about the new track.
11. A method of overwriting data in a multi-session disk,
comprising the steps of: (a) checking the size of new data
requested to be written; (b) searching the multi-session disk for a
plurality of consecutive sessions whose total size is larger than
the size of the new data; (c) overwriting the consecutive sessions
discovered in said step (b) with the new data; and (d) updating
temporary management information for tracks recorded in the
multi-session disk to reflect the overwritten sessions in the
temporary management information.
12. The method set forth in claim 11, wherein said step (b) adds up
each size of tracks included in the consecutive sessions, and
selects the consecutive sessions if the added-up size is larger
than the size of the new data.
13. The method set forth in claim 11, wherein said step (b) adds up
each size of files included in the consecutive sessions, each file
size having been written in file system information recorded at the
head of each track belonging to the consecutive sessions, and
selects the consecutive sessions if the added-up size is larger
than the size of the new data.
14. The method set forth in claim 11, wherein said step (c) pads a
remaining area not overwritten in the consecutive sessions with
null data.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a method of overwriting
data sessions selectively in a multi-session disk.
[0003] 2. Description of the Related Art
[0004] In these days, a rewritable disk such as CD-R and CD-RW as
well as a read-only disk such as CD (Compact Disk) is widely used
as a storage means of digital data.
[0005] Data written in a CD-R or a CD-RW is grouped by a logical
track unit (abbreviated `track` hereinafter) which is a data
section recorded at a time, and a CD-R or a CD-RW has at least one
session which includes at least one track where a session is
defined by a user. A CD-R or CD-RW including a plurality of
sessions is called `multi-session` disk.
[0006] Each session of a multi-session disk is defined every
request of `session close` from a user, therefore the size of each
session may be different each other. For such a multi-session disk,
new data should be written as a new session next to the last closed
session or as a new track of an unclosed last session.
[0007] Therefore, it is not possible to overwrite a useless session
including unnecessary data if it is located between neighboring
sessions. This restriction reduces disk storage efficiency. To use
the space of useless sessions, disk should be erased entirely or
area from the first useless session to the last session should be
deleted first before recording new data. However, this method is
impossible to conduct when a session including valid data exists
between the first useless session and the last session.
SUMMARY OF THE INVENTION
[0008] It is an object of the present invention to provide a method
of overwriting data written in a multi-session disk which can
overwrite at least one session selected based on the size of new
data to record.
[0009] A method of overwriting data in a multi-session disk
according to the present invention checks the size of new data
requested to be written, searches the multi-session disk for a
single or a plurality of consecutive sessions whose total size is
larger than the size of the new data, overwrites the single or the
plurality of consecutive sessions discovered in the searching step
with the new data, and updates temporary management information for
tracks recorded in the multi-session disk to reflect the
overwritten session or sessions in the temporary management
information.
[0010] The present invention may be embodied in other specific
forms without departing from the sprit or essential characteristics
thereof. The present embodiments are therefore to be considered in
all respects as illustrative and not restrictive, the scope of the
invention being indicated by the appended claims rather than by the
foregoing description and all changes which come within the meaning
and range of equivalency of the claims are therefore intended to be
embraced therein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The accompanying drawings, which are included to provide a
further understanding of the present invention, illustrate the
preferred embodiments of the invention, and together with the
description, serve to explain the principles of the present
invention, and wherein:
[0012] FIG. 1 is a simplified block diagram of a disk drive to
which a data overwriting method according to the present invention
is applicable;
[0013] FIG. 2 is an illustrative format example of data recorded in
a multi-session disk;
[0014] FIG. 3 is a flow chart of an embodiment of a multi-session
disk overwriting method according to the present invention;
[0015] FIG. 4 is an illustrative overwriting example in which one
session in a multi-session disk has been overwritten according to
the present invention; and
[0016] FIG. 5 is a flow chart of another embodiment of the present
invention which two consecutive sessions are used for being
overwritten with new data.
DETAILED DESCRIPTION OF THE PREFFERRED EMBODIMENT
[0017] In order that the invention may be fully understood, a
preferred embodiment thereof will now be described with reference
to the accompanying drawings.
[0018] FIG. 1 is a simplified block diagram of a disk drive to
which a data overwriting method according to the present invention
is applicable. The disk drive of FIG. 1 comprises an optical pickup
12 for writing/reading data to/from a rewritable disk 11, for
example, a CD-R/W; a reproduced signal processor 14 for processing
the read signals by the optical pickup 12 to restore original
digital data; a recording signal processor 17 for converting
received signals from an external device, e.g., a host to writing
signals suitable for the disk 11; a servo/drive unit 15 for
conducting servo operation for record or reproduction of the
rewritable disk 11; a microcomputer 16 for supervising all elements
to conduct record or reproduction; and a memory 13 for storing
temporary data produced while reproducing or recording.
[0019] In the disk drive configured as FIG. 1, if new data is
requested to be overwritten from a user after the multi-session
disk 11 is placed, the size of the new data is examined and a
search operation is conducted to find a session whose size is
larger than the size of the new data. If such a session is found,
that session is overwritten with the new data and the recorded new
data is grouped into a track. Due to the overwriting operation,
previous management information including position information on
the overwritten tracks and next tracks may be incorrect for the
recorded tracks, thus the management information is changed
appropriately.
[0020] The above operations explained briefly are described below
in detail.
[0021] FIG. 2 is an illustrative format example of data recorded in
the multi-session disk 11. In the example of FIG. 2, the
multi-session disk 11 has three sessions where the tracks 1 and 2
are included in the first session, the tracks 3 to 5 included in
the second, and the tracks 6 and 7 included in the third. A lead-in
`LIA` and a lead-out `LOA` area are allocated at the head and the
tail of each session, respectively.
[0022] In addition, as shown in FIG. 2, the rewritable disk 11 also
has a PCA (Power Calibration Area) and a PMA (Program Memory Area)
from most inner side besides a program area where user data is to
be written.
[0023] The PCA is prepared for testing a writing power to obtain an
optimal writing power of a laser diode equipped in the optical
pickup 12, and the PMA is for temporary management information,
marked `TK_Info #1.about.#7` in FIG. 2, for each track. The
temporary management information consists of a track index number,
start and end position expressed in time, etc. When some tracks are
grouped into a session by a session closing operation the temporary
management information written in PMA for those tracks are copied
onto a lead-in area of the closed session. File system information
about files included in a recorded track is written at the head of
each track as shown in FIG. 2.
[0024] FIG. 3 is a flow chart of an embodiment of a multi-session
disk overwriting method according to the present invention. The
flow chart depicted in FIG. 3 is described below in detail.
[0025] After the rewritable multi-session disk 11 having data
recorded as given in FIG. 2 is placed in the disk drive of FIG. 1
(S10), if a user requests the disk 11 to be overwritten with new
data the microcomputer 16 checks the size of the new data as
interpreting a write command (S11) from an external host.
[0026] Then, the microcomputer 16 examines the size of each session
to choose one session whose size is larger than that of the new
data (S12). To examine the size of each session, the microcomputer
16 reads the file system information at the head of each session
through controlling the servo/drive unit 15, first. The read
signals by the pickup 12 are converted to digital data by the
reproduced signal processor 14 and then stored in the memory 13.
The microcomputer 16 adds up each size of files belonging to one
same session through examination of the stored file system
information in the memory 13. Through this process, every size of
recorded sessions becomes known.
[0027] Another calculating method of the size of each session uses
start and end position information of each track belonging to same
session. Adding each length between start and end position of each
track will result in the size of each session.
[0028] If at least one session is larger than the size of the new
data (S13), for example, if the size of the second session
including tracks 3 to 5 is larger than the size of the new data in
the example of FIG. 2, the microcomputer 16 reads all file system
information at each head of tracks 3 to 5 and provides the file
information for an external host (S14). The reason the file
information is provided is to receive confirmation on whether the
second session to be overwritten is not useful any more.
[0029] If a user still requests to overwrite with the new data
(S15) at this confirming step, the microcomputer 16 overwrites the
second session as a single track `nTK3` with the pulse-formatted
new data by the recording signal processor 17 as shown in FIG. 4
(S16). However, because the original size of the second session is
larger than the size of the new data, a remaining section arises in
the second session. Non-overwritten data in the remaining section
right after the new track `nTK3` may cause a CRC error in
reproduction, thus, the remaining section is preferably padded with
null data (S17).
[0030] In addition, because three tracks 3 to 5 are changed to one
track `nTK3` due to the overwriting operation, old track
information `TK_Info #1.about.#7` written in PMA is different from
real recorded tracks, therefore, the old track information `TK_Info
#3.about.#5` for the overwritten tracks 3 to 5 should be replaced
with a new track information `nTK_Info #3` for the new track `nTK3`
to correct the temporary management information in PMA (S18).
[0031] For PMA correcting operation, the microcomputer 16 reads
track information `TK_Info #6, #7` associated with the tracks 6 and
7 included in the third session following the overwritten second
session, overwrites the location reserved for the third track
management information with track information `nTK_Info #3` about
the new track `nTK3`, and overwrites the locations reserved for the
fourth and the fifth track management information with the read
track information `TK_Info #6, #7` after modifying the track index
numbers 6 an 7 written in the read track information `TK_Info #6,
#7` to 4 and 5, respectively.
[0032] And, because the overwritten session has been already
closed, the lead-in information of the overwritten session is also
updated with the information about the new track `nTK3` (S19).
[0033] FIG. 4 shows a changed recording diagram after user data in
the program area and all management information in PMA are updated
according to the above-explained operations. As shown in FIG. 4, it
is possible to selectively overwrite an arbitrary session with a
single track containing new data in a multi-session disk.
[0034] If there are two or more sessions each of which has larger
size than the new data (S13), the microcomputer 16 provides
respective file information about all files included in the
sessions for the external host (S21) in order that a user might
choose one among the sessions.
[0035] When a user chooses one session which has useless files
(S22) the microcomputer 16 conducts the above-explained overwriting
operations (S16.about.S19). If there is no session whose size is
larger than that of the new data, the microcomputer 16 writes the
new data as a new session next to the last session or as a new
track of an unclosed last session the same as conventional methods
do (S31).
[0036] Instead of writing new data after the last track, two or
more consecutive sessions may be overwritten at a time with the new
data if total size of those sessions is larger than the new data.
FIG. 5 depicts a flow chart according to this embodiment where two
consecutive sessions are searched for being overwritten.
[0037] If there is no single session whose size is larger than that
of the new data to overwrite with, the microcomputer 16 searches
for two consecutive sessions whose total size is larger than that
of the new data (S42,S43). If the number of two consecutive
sessions is one the microcomputer 16 provides file information
about files included in the two consecutive sessions for a user
(S44). After that, if a user still wants data overwriting (S45) the
microcomputer 16 overwrites the two sessions with the new data
(S46). Due to this overwriting operation, two consecutive sessions
are made to one session. The remaining area of the two sessions not
overwritten with the new data is filled with null data, too
(S47).
[0038] Because all tracks included in the two consecutive sessions
become one track, the track information in PMA is amended as
explained above (S48). Lastly, management information in a lead-in
area of the former session of the two is updated with the
information about the newly recorded track (S49).
[0039] If the number of two consecutive sessions is greater than
one at the steps S42 and S43 the microcomputer 16 provides file
information about files included in each two consecutive sessions
for a user (S51) in order that a user might select one among a
plurality of two consecutive sessions (S52). If two consecutive
sessions are selected the above-explained overwriting operations
(S46.about.S49) are conducted to overwrite the selected two
sessions with new data.
[0040] Instead of two consecutive sessions, three or more
consecutive sessions can be used to overwrite with new data in the
embodiment of FIG. 5.
[0041] The method of overwriting data in a multi-session disk
according to the present invention can overwrite selectively one or
more sessions having useless data without affecting other sessions
having important data, thereby improving storage efficiency of a
rewritable disk. Furthermore, because track information in PMA
exactly reflects real recorded tracks after the session selective
overwriting, a location error never occurs when appending or
reproducing data.
* * * * *