U.S. patent application number 11/832172 was filed with the patent office on 2007-11-22 for optical information storage medium.
This patent application is currently assigned to Samsung Electronics Co., Ltd.. Invention is credited to Chong-sam Chung, Kyung-geun Lee, Ghang-urin Park, In-sik Park, Du-seop Yoon.
Application Number | 20070268796 11/832172 |
Document ID | / |
Family ID | 31987372 |
Filed Date | 2007-11-22 |
United States Patent
Application |
20070268796 |
Kind Code |
A1 |
Lee; Kyung-geun ; et
al. |
November 22, 2007 |
OPTICAL INFORMATION STORAGE MEDIUM
Abstract
An optical information storage medium includes a lead-in area, a
lead-out area, and a user data area between the lead-in and
lead-out areas and in which user data is recorded. A first track
pitch between adjacent tracks in a first subarea of the lead-in
area is greater than a second track pitch between adjacent tracks
in a second subarea of the lead-in area other than first subarea
and wherein the first subarea comprises optical storage
medium-related information.
Inventors: |
Lee; Kyung-geun;
(Gyeonggi-do, KR) ; Park; In-sik; (Gyeonggi-do,
KR) ; Chung; Chong-sam; (Gyeonggi-do, KR) ;
Yoon; Du-seop; (Gyeonggi-do, KR) ; Park;
Ghang-urin; (Gyeonggi-do, KR) |
Correspondence
Address: |
STEIN, MCEWEN & BUI, LLP
1400 EYE STREET, NW
SUITE 300
WASHINGTON
DC
20005
US
|
Assignee: |
Samsung Electronics Co.,
Ltd.
Suwon-si
KR
|
Family ID: |
31987372 |
Appl. No.: |
11/832172 |
Filed: |
August 1, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10633564 |
Aug 5, 2003 |
7272106 |
|
|
11832172 |
Aug 1, 2007 |
|
|
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Current U.S.
Class: |
369/44.26 ;
G9B/7.033 |
Current CPC
Class: |
G11B 7/0906 20130101;
G11B 7/00736 20130101; G11B 7/24079 20130101 |
Class at
Publication: |
369/044.26 |
International
Class: |
G11B 7/00 20060101
G11B007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 10, 2002 |
KR |
2002-54756 |
Claims
1. An optical information storage medium comprising: a lead-in
area; a lead-out area; and a user data area formed between the
lead-in and lead-out areas and in which user data is recorded,
wherein a first track pitch between adjacent tracks in a first
subarea of the lead-in area is greater than a second track pitch
between adjacent tracks in a second subarea of the lead-in area
other than first subarea and wherein the first subarea comprises
optical storage medium-related information.
2. The optical information storage medium of claim 1, wherein the
optical information storage medium-related information comprises at
least one of information about the type of information storage
medium, information about the number of recording layers,
information about a recording speed, and information about a disk
size of the information storage medium.
3. An apparatus to optically transfer data with respect to an
optical information storage medium that comprises a lead-in area, a
lead-out area and a user data area, the apparatus comprising: an
optical unit radiating a beam to read the data in the optical
information storage medium; and a controller to control the optical
unit to read first data from first tracks in a first subarea of the
lead-in area, and to read user data from the user data area;
wherein: adjacent pairs of the first tracks have a first pitch,
adjacent pairs of second tracks in a second sub area of the lead in
area having a second pitch other than the first pitch.
4. The apparatus of claim 3, wherein the first subarea comprises
optical information storage medium-related information.
5. The apparatus of claim 4, wherein the disk related information
comprises at least of one information about the type of information
storage medium, information about the number of recording layers,
information about a recording speed, and information abut the disk
size.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional of U.S. Ser. No.
10/633,564, filed on Aug. 5, 2003, now pending, the disclosure of
which is incorporated by reference. This application also claims
the benefit of Korean Patent Application No. 2002-54756, filed on
Sep. 10, 2002 in the Korean Intellectual Property Office, the
disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an optical information
storage medium, and more particularly, to an optical information
storage medium in which a track pitch in all or a portion of a
lead-in area is different from a track pitch in remaining areas of
the optical information storage medium so that the reliability of
reproduction of important optical information storage
medium-related information can be improved.
[0004] 2. Description of the Related Art
[0005] Optical discs are generally used as information storage
media of optical pickup devices, which record information on and/or
reproduce information from the optical discs without contacting the
optical discs. Optical discs are classified as either compact discs
(CDs) or digital versatile discs (DVDs) according to their
information recording capacity. CDs and DVDs further include 650 MB
CD-Rs, CD-RWs, 4.7 GB DVD+RWs, DVD-random access memories
(DVD-RAMs), DVD-R, DVD-rewritables (DVD-RWs), and so forth.
Read-only discs include 650 MB CDs, 4.7 GB DVD-ROMs, and the like.
Furthermore, high-density digital versatile discs (HD-DVDs) have
been developed which have a recording capacity of 20 GB or
more.
[0006] Various methods of increasing the recording capacity of
optical discs have been studied. One method of increasing the
recording capacity is to reduce a size of an optical spot focused
on an optical disc. To reduce the size of the optical spot, the
wavelength of a laser light source should be shortened or a
numerical aperture (NA) of an objective lens should be increased.
Further, the track pitch of the optical disc should be reduced. The
track pitch refers to a minimum distance measured from a central
line of one track to a central line of an adjacent track.
[0007] FIG. 1 illustrates the structure of a conventional DVD-ROM
110. The DVD-ROM 110 includes a user data area 105 in which user
data is recorded. A lead-in area 100 is formed inside the user data
area 105. A lead-out area 110 which is formed outside the user data
area 105. Data is recorded as dots in the lead-in area 100, the
user data area 105, and the lead-out area 110. Also, the track
pitch is 0.74 .mu.m in the lead-in area 100, the user data area
105, and the lead-out area 110.
[0008] The track pitch tends to be reduced when increasing the
recording capacity. However, since an optical spot focused on a
track may reach an adjacent track, the possibility that cross-talk
will occur becomes high as the track pitch is reduced. If
cross-talk occurs, an abnormal reproduction signal is output. Thus,
as the track pitch is reduced, there is an increase in abnormal
reproductions of information.
[0009] In particular, if information is abnormally reproduced from
an area in which is recorded important information in recording
and/or reproducing data, this abnormal reproduction may gravely
affect a recording and/or reproduction efficiency of a disc.
Accordingly, the track pitch is required to be adjusted in
accordance with an increase in the recording capacity of a storage
medium and the importance of data.
SUMMARY OF THE INVENTION
[0010] The present invention provides an optical information
storage medium in which a track pitch in an area in which is
recorded important optical information storage medium-related
information is different from a track pitch in a user data area in
which is recorded user data so that the efficiency and reliability
of the reproduction of data can be improved.
[0011] Additional aspects and/or advantages of the invention will
be set forth in part in the description which follows and, in part,
will be obvious from the description, or may be learned by practice
of the invention.
[0012] According to an aspect of the present invention, an optical
information storage medium includes a lead-in area, a lead-out area
that is formed outside the lead-in area, and a user data area
disposed between the lead-in and lead-out areas and in which user
data is recorded where pits are formed in first tracks of the
lead-in area, second tracks of remaining area including the user
data area, and the lead-out area, and a track pitch of between
adjacent first tracks in all or a portion of the lead-in area is
different from a track pitch between adjacent second and/or third
tracks in the remaining areas of the optical information storage
medium.
[0013] It is preferable, but not required, that the first track
pitch is greater than the second track pitch in the remaining area
of the optical information storage medium.
[0014] According to an aspect of the invention, the lead-in area
includes an area in which optical information storage
medium-related information is recorded and an area in which copy
protection information is recorded.
[0015] It is preferable, but not required, that the first track
pitch in at least one of the areas of the lead-in area is greater
than the second track pitch in the remaining area of the optical
information storage medium.
[0016] It is preferable, but not required, that a ratio of tracking
error signals detected in the area having the first track pitch to
tracking error signals detected in the area having the second track
pitch is 1.5 or more.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The above and/or other features and advantages of the
present invention will become more apparent and more readily
appreciated by describing in detail exemplary embodiments thereof
with reference to the accompanying drawings in which:
[0018] FIG. 1 illustrates the schematic structure of a conventional
DVD-ROM;
[0019] FIG. 2 illustrates the schematic structure of an optical
information storage medium according to an embodiment of the
present invention;
[0020] FIG. 3A illustrates a phase tracking error signal (a
differential phase detect (DPD) signal) when a track pitch is 0.32
.mu.m;
[0021] FIG. 3B illustrates a phase tracking error signal (a DPD
signal) when a track pitch is 0.35 .mu.m; and
[0022] FIG. 4 is a block diagram of a recording and/or reproducing
apparatus according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0023] Reference will now be made in detail to the present
embodiments of the present invention, examples of which are
illustrated in the accompanying drawings, wherein like reference
numerals refer to the like elements throughout. The embodiments are
described below in order to explain the present invention by
referring to the figures.
[0024] Referring to FIG. 2, an optical information storage medium
1000 according to an embodiment of the present invention includes a
user data area 15, a lead-in area 10 which is formed inside the
user data area 15, and a lead-out area 20 which is formed outside
the user data area 15 and the lead-in area 10. A first track pitch
in all or a portion of the lead-in area 10 is different from a
second track pitch in remaining areas of the optical information
storage medium 1000 including the user data and lead-out areas 15,
20.
[0025] The lead-in area 10 includes areas in which is recorded
important data in reproduction from the optical information storage
medium. Examples of the important data include optical information
storage medium-related information, which is recorded in area 10a,
and copy protection information, which is recorded in area 10b. The
optical information storage medium-related information contains
information on the type of storage medium (such as whether the
medium 1000 is a recordable disc, write-once disc, or a read-only
disc), information on the number of recording layers, information
on the recording speed, and information on the size of the optical
information storage medium 1000 (disc).
[0026] It is preferable, but not required, that a track pitch in at
least one of the areas 10a and 10b is the first track pitch which
is greater than the second track pitch in the remaining areas
except the areas 10a and 10b. It is understood that additional
important information in reproduction from the optical information
storage medium 1000 may be recorded, and the track pitch in the
entire lead-in area 10 may be the first track pitch which is
greater than the second track pitch in the remaining areas of the
optical information storage medium 1000.
[0027] The optical information storage medium according to an
embodiment of the present invention is read-only optical
information storage medium. The pits are formed everywhere in the
lead-in area 10, the user data area 15, and the lead-out area 20.
The pits are formed in a substrate in advance when manufacturing
the read-only embodiment of the optical information storage medium
1000. If data is recorded as the pits, the pits can be formed in
the lead-in area 10 and the user data area 15 without stopping a
process of forming the pits. Thus, a process of manufacturing an
optical information storage medium can be simplified and the time
required for performing the process can be reduced.
[0028] One method of performing a tracking operation using the pits
is a differential phase detect (DPD) method. For example, the DPD
method is used to realize a track servo depending on the phase
shift of an optical spot focused on a quarter photodetector. The
DPD method is well known, and thus will not be described in detail
herein. According to the DPD method, when track pitches on the
optical information storage medium are different, an output
tracking error signals (such as differential phase tracking error
signals) are different. For example, FIG. 3A illustrates a DPD
signal when the track pitch is 0.32 .mu.m, and FIG. 3B illustrates
a DPD signal when the track pitch is 0.35 .mu.m. Here, when the
same reproduction power is output, the amplitude of a phase
tracking error signal (a DPD signal) in the track pitch of 0.32
.mu.m was about 1.46V. In contrast, the amplitude of the DPD signal
in the track pitch of 0.35 .mu.m was about 2.31V. Thus, the
amplitude of the DPD signal when the track pitch is larger
increased about 1.58 times the amplitude of the DPD signal when the
track pitch is smaller. As can be seen in FIGS. 3A and 3B, as the
track pitch increased, the amplitude of the DPD signal is
increased. As the amplitude of the DPD signal is increased, an
error detecting efficiency is improved. Thus, the reproduction
efficiency and reliability are improved as the track pitch
increased.
[0029] According to the result of simulations, it was found that,
when the track pitch TP in the area 10a or the area 10b is I and
the track pitch TP in the remaining areas of the optical
information storage medium is II, it is preferable, but not
required, that a ratio of a tracking error signal, particularly, a
phase tracking error signal, to each of the track pitches TP is 1.5
or more as expressed by equation 1 set forth below: Tracking
.times. .times. Error .times. .times. Signal TP = I Tracking
.times. .times. Error .times. .times. Signal TP = II .gtoreq. 1.5 (
1 ) ##EQU1##
[0030] The optical information storage medium according to
embodiments of the present invention can be applied to an optical
information storage medium having one or more recording surfaces.
In other words, if the optical information storage medium has a
plurality of recording surfaces, the track pitch in all or a
portion of a lead-in area of each of the plurality of recording
surfaces can be greater than the track pitch in the remaining area
of each of the plurality of recording surfaces. Accordingly, the
track pitch in a portion of the lead-in area in which important
information is recorded can be greater than the track pitch in the
remaining area of the optical information storage medium so that
the reproduction reliability of the important information can be
increased.
[0031] While not specifically so limited, it is understood that the
information storage medium can include the CD-Rs, CD-RWs, DVD-RWs,
DVD-RAMs, DVD+RWs, as well as next generation high definition DVDs,
such as Blu-ray discs and Advanced Optical Discs (AODs). Further,
it is understood the information storage medium need not include
lead-in and/or lead-out areas.
[0032] FIG. 4 is a block diagram of a recording and/or reproducing
apparatus according to an embodiment of the present invention.
Referring to FIG. 4, the recording apparatus includes a
recording/reading unit 1001, a controller 1002, and a memory 1003.
The recording/reading unit 1001 records data on a disc 1000, which
is an embodiment of an information storage medium 1000 of the
present invention, and reads the data from the disc 1000. The
controller 1002 records and reproduces data from tracks having
first and second track pitches according to the present invention
as set forth above in relation to FIGS. 2 through 3B.
[0033] While not required in all aspects, it is understood that the
controller 1002 can be computer implementing the method using a
computer program encoded on a computer readable medium. The
computer can be implemented as a chip having firmware, or can be a
general or special purpose computer programmable to perform the
method.
[0034] In addition, it is understood that, in order to achieve a
recording capacity of several dozen gigabytes, the
recording/reading unit 1001 could include a low wavelength, high
numerical aperture type unit usable to record dozens of gigabytes
of data on the disc 1000. Examples of such units include, but are
not limited to, those units using light wavelengths of 405 nm and
having numerical apertures of 0.85, those units compatible with
Blu-ray discs, and/or those units compatible with Advanced Optical
Discs (AOD).
[0035] As described above, in an optical information storage medium
according to the present invention, the track pitch in an area,
such as an optical information storage medium-related information
area or a copy protection information area of a lead-in area, in
which important information is recorded, is greater than the track
pitch in the remaining areas of the optical information storage
medium. Thus, reliable reproduction of the important information
can be achieved without deteriorating a signal due to cross-talk
occurring between adjacent tracks during reproduction of the
important information.
[0036] While the present invention has been particularly shown and
described with reference to exemplary embodiments thereof, it will
be understood by those of ordinary skill in the art that various
changes in form and details may be made therein without departing
from the spirit and scope of the present invention as defined by
the following claims and equivalents thereof.
* * * * *