Dynamic information storage or retrieval – Condition indicating – monitoring – or testing – Including radiation storage or retrieval
Reexamination Certificate
1998-12-31
2003-08-19
Hindi, Nabil (Department: 2655)
Dynamic information storage or retrieval
Condition indicating, monitoring, or testing
Including radiation storage or retrieval
C369S047270
Reexamination Certificate
active
06608804
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of Korean Application No. 80595/1997, filed Dec. 31, 1997, in the Korean Patent Office, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an optical disk player, and more particularly, to a method for discriminating the type of a disk mounted into an optical disk player.
2. Description of the Related Art
An optical disk player reproduces data recorded on an optical disk, such as a CD (Compact Disk), CD-ROM (Compact Disk-Read Only Memory), LD (Laser Disk), MD (Mini Disk), DVD (Digital Video Disk), etc. Since there are various types of optical disks, the optical disk player should discriminate the type of a disk mounted therein. Especially, a DVD player which uses a CD-series disk as well as a DVD-series disk may not accurately reproduce data unless it determines which type of disk is mounted therein.
Referring to
FIG. 1
, an optical pickup
102
optically picks up information recorded on a disk and generates an electrically converted RF (radio frequency) signal. The optical pickup
102
has a focusing actuator and a tracking actuator. The focusing actuator is driven by the control of a DSSP (Digital Servo Signal Processor)
114
and shifts an object lens toward an optical axis. The tracking actuator shifts the object lens toward the radial direction of a disk
100
to seek a track. A spindle motor
104
is driven under the control of the DSSP
114
to rotate a disk
100
at a CLV (Constant Linear Velocity). A sled feed motor
106
is driven under the control of the DSSP
114
to move the optical pickup
102
.
An RF amplifier
108
amplifies the RF signal received from the optical pickup
102
and shapes a waveform of the amplified RF signal. The RF amplifier
108
supplies a modulation signal during writing to a DSP (Digital Signal Processor)
110
and supplies signals for tracking servo and focusing servo to the DSSP
114
. If the disk
100
is a CD-series disk, the modulation signal is an EFM (Eight to Fourteen Modulation) signal. If the disk
100
is a DVD-series disk, the modulation signal is an EFM plus signal. The DSP
110
also restores a BCA (Burst Cutting Area) code reproduced from a BCA code area on the disk
100
. An output processor
112
processes the data generated from the DSP
110
and generates a final output signal such as an audio signal. The DSSP
114
, controlled by a microcomputer
116
, controls tracking servo and focusing servo of the optical pickup
102
, sled servo using the sled feed motor
106
, and spindle servo, in response to signals received form the RF amplifier
108
and the DSP
110
. The microcomputer
116
, which is a main controller, controls the overall operation of an optical disk player.
FIG. 2
illustrates a general BCA code structure. The BCA code is comprised of a BCA preamble
200
, BCA information data I
BCA
202
, an error detecting code EDC
BCA
204
, and error correcting code ECC
BCA
206
, and a BCA postamble
208
. The BCA code is written in the disk together with a corresponding synchronizing byte. That is, the 4-byte BCA preamble
200
is written in the disk together with a BCA synchronizing byte SB
BCA
. The BCA information data I
BCA
202
, the error detecting code EDC
BCA
204
, the error correcting code ECC
BCA
206
, and the BCA postamble
208
are written in the disk together with a BCA re-synchronizing byte RS
BCA
.
The BCA information data I
BCA
202
(I
0
-I
16n-5
) can be expressed by the following equation (1). The error detecting code EDC
BCA
204
(ED
0
-ED
3
) is a parity for detecting an error of the BCA information data I
BCA
202
and is expressed by the following equations (2) and (3) and as the remainder obtained by dividing input data I
BCA
(x) by a polynomial G(x) which can be expressed by the following equation (4). A bit operation is expressed using a small letter ‘x’.
I
BCA
(
x
)
=
∑
i
=
32
128
n
-
1
bi
·
x
i
(
1
)
EDC
BCA
(
x
)
=
∑
i
=
0
31
bi
·
x
i
(
2
)
EDC
BCA
(
x
)=
I
BCA
(
x
)
modG
(
x
) (3)
G
(
x
)=
x
32
+x
31
+x
4
+1 (4)
The error correcting code ECC
BCA
206
(C
0,0
-C
3,3
) is a parity for correcting errors of the BCA information data I
BCA
202
and the error detecting code EDC
BCA
204
and is expressed as the remainder obtained by dividing input data I
BCAj
(x) by a polynomial G
pBCA
(x) as shown in the following equations (5)-(9). A byte operation is expressed using a capital letter ‘X’.
R
BCAj
(
X
)
=
∑
i
=
0
3
C
j
,
i
·
X
3
-
i
(
5
)
D
BCAj
(
X
)
=
∑
i
=
0
4
n
-
2
I
j
+
4
i
·
X
51
-
i
+
ED
j
·
X
52
-
4
n
(
6
)
ECC
BCAj
(
X
)=
I
BCAj
(
X
)
modG
pBCA
(
X
) (7)
G
pBCA
(
X
)
=
∏
k
=
0
3
(
X
+
a
k
)
(
8
)
Gp
(
x
)=
x
8
+x
4
+x
3
+x
2
+1 (9)
On the other hand, as shown in the BCA code structure of
FIG. 2
, there is a re-synchronizing byte RS
BCA1
area which is not used in the BCA code area. That is, the BCA code is written in the BCA code area of a lead-in area on the disk and there is an unused re-synchronizing byte area in the BCA code area. In the present invention, the BCA code including a disk code is written in the disk. Therefore, the BCA code includes the disk and the disk having the disk code in the BCA code area performs the normal operation in the optical disk player.
A conventional method for discriminating the type of a disk used in the DVD player will now be described. If the user inserts the DVD-series or CD-series disk into the DVD player and a tray is closed, the DVD player sets its operating mode to a CD mode and starts focus searching. During the focus searching, the DVD player checks whether there is a focus error. If two focus error signals are respectively generated in the up and down movement directions of a lens, the DVD player judges the inserted disk to be a dual layer disk. If one focus error signal is generated, the inserted disk is regarded as a single layer disk. If focusing has ended, the DVD player rotates a spindle motor and checks a phase difference between E and F signals detected by an E/F photo diode of an optical pickup. If the phase difference is 180°, the inserted disk is judged to be the CD-series disk, and if there is no phase difference, it is regarded as the DVD-series disk. Thereafter, the DVD player checks a lead-in area of the disk to distinguish a V-CD (video CD), a CD-audio from the CD-series disk, and DVD-single, DVD-dual from the DVD-series disk. Thus, the disk discriminating operation is completed. This operation is controlled by a microcomputer which is a main controller of the DVD player.
Meanwhile, since the above-described disk discriminating operation is performed step by step, the microcomputer passes through many steps for detecting the type of disk. Therefore, the load on the microcomputer increases, and it takes a lot of time to discriminate the type of the disk. If the disk discriminating process has not ended in a short time period, a waiting time until a normal playback state is performed may be very long. Moreover, a check as to whether the disk is a dual layer or a single layer is made by using the focus error signal, and a determination as to whether the disk is the CD-series or the DVD-series is made from the phase difference between the E and F signals by utilizing the fact that a track pitch of the CD-series disk is different from that of the DVD-series disk. Therefore, if the disk has scratches, the disk player may wrongly detect the type of the disk. When considering future optical disks which will be put on the market, it becomes very difficult to discriminate the type of the disk and there will be a strong possibility that the type of the disk will be wrongly detected.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a disk having a unique code for
Samsung Electronics Co,. Ltd.
Staas & Halsey , LLP
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