U.S. patent application number 11/390157 was filed with the patent office on 2006-08-10 for recording/reproducing apparatus and recording/reproducing method.
This patent application is currently assigned to Sony Corporation. Invention is credited to Shoei Kobayashi, Tadaaki Nomoto.
Application Number | 20060176785 11/390157 |
Document ID | / |
Family ID | 17857884 |
Filed Date | 2006-08-10 |
United States Patent
Application |
20060176785 |
Kind Code |
A1 |
Kobayashi; Shoei ; et
al. |
August 10, 2006 |
Recording/reproducing apparatus and recording/reproducing
method
Abstract
A recording/reproducing apparatus comprising an OP head 11, a
wobble circuit 12, a system controller 13, and an address-decoding
timing generator 14. The wobble circuit 12 extracts a wobble signal
from the signal the OP head 11 has read. A PLL circuit for
generating a sync signal from the wobble signal is held while no
normal wobble signal is generated. The address-decoding timing
generator (Address DEC TG) 14 receives a signal the OP head 11 has
reproduced, decodes the address represented by the signal, and
supplies the address data to the system controller 13. The
generator 14 also generates a timing signal from the sync signal
supplied from the wobble circuit 12 and supplies the timing signal
to the other components of the recording/reproducing apparatus.
Inventors: |
Kobayashi; Shoei; (Kanagawa,
JP) ; Nomoto; Tadaaki; (Tokyo, JP) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
Sony Corporation
Shinagawa-ku
JP
|
Family ID: |
17857884 |
Appl. No.: |
11/390157 |
Filed: |
March 28, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09689005 |
Oct 12, 2000 |
7057985 |
|
|
11390157 |
Mar 28, 2006 |
|
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Current U.S.
Class: |
369/44.28 ;
348/E5.021; 369/47.1; 369/59.1; 386/E5.064; G9B/20.009; G9B/27.027;
G9B/7.025 |
Current CPC
Class: |
G11B 20/10 20130101;
H04N 5/126 20130101; H04N 9/8042 20130101; G11B 7/0053 20130101;
G11B 2220/20 20130101; G11B 27/24 20130101; H04N 5/85 20130101;
H03L 7/14 20130101; H03L 7/18 20130101 |
Class at
Publication: |
369/044.28 ;
369/047.1; 369/059.1 |
International
Class: |
G11B 7/00 20060101
G11B007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 20, 1999 |
JP |
P11298301 |
Claims
1-6. (canceled)
7. A recording/reproducing apparatus for recording and reproducing
data on and from an optical disk that has an address data area
having embossed pits and a recording/reproducing area having a
wobbling spiral groove, said apparatus comprising: head means for
reading address data from the address data area and writing and
reading a signal in and from the recording/reproducing area; system
controller means for controlling components of the
recording/reproducing apparatus including servo circuit means, the
system controller means controlling the servo circuit means for
moving the head means to a desired address position on the optical
disk; and wobble-signal processing means for extracting a wobble
signal from the signal the head means obtains from the wobbling
spiral groove and for providing the wobble signal to a PLL circuit
means for producing a sync signal from the wobble signal, wherein
the system controller means further produces a wobble enable signal
when the system controller means controls switching of the
recording/reproducing apparatus between at least one of recording
and reproducing operations, said PLL circuit means further
providing an unchanging sync signal in response to receiving the
wobble enable signal.
8. A recording/reproducing apparatus for recording and reproducing
data on and from an optical disk that has an address data area
having embossed pits and a recording/reproducing area having a
wobbling spiral groove, said apparatus comprising: head means for
reading address data from the address data area and writing and
reading a signal in and from the recording/reproducing area; system
controller means for controlling components of the
recording/reproducing apparatus including servo circuit means, the
system controller means controlling the servo circuit means for
moving the head means to a desired address position on the optical
disk; and wobble-signal processing means for extracting a wobble
signal from the signal the head means obtains from the wobbling
spiral groove and for providing the wobble signal to a PLL circuit
means for producing a sync signal from the wobble signal, wherein
the system controller means further produces a wobble enable signal
when the system controller means controls the servo circuit means
to move the head means to a desired address position on the optical
disc, and said PLL circuit means further providing an unchanging
sync signal in response to receiving the wobble enable signal.
9. A recording/reproducing apparatus for recording and reproducing
data on and from an optical disk that has an address data area
having embossed pits and a recording/reproducing area having a
wobbling spiral groove, said apparatus comprising: head means for
reading address data from the address data area and writing and
reading a signal in and from the recording/reproducing area; system
controller means for controlling components of the
recording/reproducing apparatus including servo circuit means, the
system controller means controlling the servo circuit means for
moving the head means to a desired address position on the optical
disk; and wobble-signal processing means for extracting a wobble
signal from the signal the head means obtains from the wobbling
spiral groove and for providing the wobble signal to a PLL circuit
means for producing a sync signal from the wobble signal, wherein
the system controller means further produces a wobble enable signal
when the wobble-signal processing means otherwise does not provide
a wobble signal extracted from the signal the head means obtains
from the wobbling spiral groove and provides the wobble enable
signal to the PLL circuit means, said PLL circuit means further
providing an unchanging sync signal in response to receiving the
wobble enable signal.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a recording/reproducing
apparatus and a recording/reproducing method, both designed to
record and reproduce data on and from a disk-shaped recording
medium that has an address data area having emboss pits and a
recording/reproducing area having a wobbling spiral groove.
[0002] There is known a method of recording address data on an
optical disk, in which pits are made in the process of forming the
disk, thereby recording the address data. For example, the
recording surface of the disk is divided into blocks called
"sectors", each for storing 2048 (2 k) bytes of user data. Header
data is recorded, in the form of pits, in the header area of each
sector and is used as sector address. A recording/reproducing
apparatus first reads the sector address. If the sector address
pertains to a desired sector, the apparatus either records data on
or reproduces data from the recording/reproducing area that follows
the header area.
[0003] An optical disk is known, which has a spiral groove made in
its surface and wobbling at a specific frequency. A
recording/reproducing apparatus reads a wobble signal from the
optical disk and reproduces synchronization data from the wobble
signal. The amount of the synchronization data is measured in the
recording/reproducing apparatus, thereby interpolating the address
position, even if the disk has defects, destroying the address
data. The apparatus can therefore achieve continuous
data-recording. In addition, the frequency of the wobble signal can
be used to control the rotation speed of the spindle motor
incorporated in the recording/reproducing apparatus.
[0004] As described above, the recording/reproducing apparatus
generates the synchronization data from the wobble signal and uses
the frequency of the wobble signal to control the rotation speed of
the spindle motor. The wobble signal must therefore be detected
with high precision. It is difficult, however, to detect the wobble
signal when a complex operation is performed as the operating mode
is switched from the recording mode to the reproducing mode.
[0005] The wobble signal may become discontinuous or distorted when
a track jump occurs, when the operating mode is switched from the
reproducing mode to the recording mode, or when the head crosses
the address data area. If this happens, the high-precision
synchronization data cannot be generated from the wobble
signal.
BRIEF SUMMARY OF THE INVENTION
[0006] The present invention has been made in view of the
foregoing. The object of the present invention is to provide a
recording/reproducing apparatus and a recording/reproducing method,
both capable of remove any signal generated when the wobble signal
is either discontinuous or distorted, while the data is being
recorded on or reproduced from a disk-shaped recording medium.
[0007] To achieve this object, a recording/reproducing apparatus
according to the invention is designed to record and reproduce data
on and from a disk-shaped recording medium that has an address data
area having emboss pits and a recording/reproducing area having a
wobbling spiral groove. The apparatus comprises: head means for
reading address data from the address data area and writing and
reading a signal in and from the recording/reproducing area; and
wobble-signal processing means for extracting a wobble signal from
the signal the head means has read from the recording/reproducing
area, and for holding a PLL circuit designed to reproduce a sync
signal from the wobble signal, while no normal wobble signal is
obtained.
[0008] To attain the object mentioned above, a
recording/reproducing method according to this invention is
designed to record and reproduce data on and from a disk-shaped
recording medium that has an address data area having emboss pits
and a recording/reproducing area having a wobbling spiral groove.
The method comprises the steps of extracting a wobble signal from a
signal head means has read from the recording/reproducing area; and
holding a PLL circuit designed to reproduce a sync signal from the
wobble signal, while no normal wobble signal is obtained.
[0009] With the present invention it is possible to remove any
signal generated when the wobble signal is, either discontinuous or
distorted, thereby obtaining a synchronization signal of high
precision.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0010] FIG. 1 is a block diagram illustrating an apparatus for
recording and reproducing data on and from an optical disk, which
is an embodiment of the present invention:
[0011] FIG. 2 is a diagram illustrating an optical disk on and from
which the recording/reproducing apparatus records and reproduces
data;
[0012] FIG. 3 is a diagram depicting the address data area and
recording/reproducing area of the optical disk;
[0013] FIG. 4 is a block diagram showing the wobble circuit
incorporated in the recording/reproducing apparatus;
[0014] FIG. 5 is a timing chart illustrating how a wobble signal is
generated during the data-recording and how a synchronization
signal is generated from the wobble signal;
[0015] FIG. 6 is a timing chart explaining how a wobble signal is
generated during the track jump and how a synchronization signal is
generated from this wobble signal;
[0016] FIG. 7 is a timing chart showing how a wobble signal is
generated from the address data area and how a synchronization
signal is generated from the wobble signal;
[0017] FIG. 8 is a block diagram illustrating another type of a
wobble circuit that generates a synchronization signal from a
wobble signal; and
[0018] FIG. 9 is a timing chart explaining how the wobble circuit
of FIG. 8 generates a wobble signal and how a synchronization
signal is generated from the wobble signal generated by the wobble
circuit.
DETAILED DESCRIPTION OF THE INVENTION
[0019] An embodiment of the present invention will be described,
with reference to the accompanying drawings.
[0020] The embodiment is an optical disk apparatus for recording
and reproducing data on and from an optical disk that has an
address data area having embossed pits and a recording/reproducing
area having a wobbling spiral groove.
[0021] FIG. 1 shows the optical disk apparatus. The optical disk
apparatus comprises an optical head (OP head) 11, a wobble circuit
12, a system controller (syscon) 13, and an address-decoding timing
generator (Address DEC TG) 14. The OP head 11 applies a laser beam
to an optical disk 10 to read and write data on and from the
optical disk 10. The wobble circuit 12 obtains a wobble signal from
the read signal supplied from the OP head 11 and generates a sync
signal. The address-decoding timing generator (Address DEC TG) 14
receives a reproduced signal from the optical head 11 and decodes
the address of the reproduced signal, thereby generating address
data. The address data is supplied to the system controller 13. The
generator 14 receives the sync signal from the wobble circuit 12
and generates a timing signal from the sync signal. The sync signal
is supplied to some other components via the system controller
13.
[0022] The optical disk apparatus further comprises a read/write
(RW) circuit 15, a modem circuit 16, an ECC encoder/decoder 17, a
servo circuit 18, a spindle motor 19, and a spindle circuit 20. The
read/write (RW) circuit 15 performs recording compensation to
record data on the disk 10 and reproduce binary data by means of a
phase-locked loop (PLL) and the like to reproduce data from the
disk 10. The modem circuit 16 modulates the data to be recorded on
the optical disk 10 and demodulates data reproduced from the
optical disk 10. The ECC encoder/decoder 17 encodes (ENC) and
decodes (DEC) an error correcting code (ECC). The servo circuit 18
performs the seek operation of the OP head 11 and effects servo
control on the two-axis actuator incorporated in the OP head 11.
The spindle circuit 20 controls the spindle motor 19. Note that the
system controller 13 controls any other component, either directly
or indirectly.
[0023] The OP head 11 is composed of an optical system, a
reproduction IV amplifier, a two-axis actuator and the like. The
optical system includes a laser diode LD.
[0024] The optical disk 10 on and from which the optical disk
apparatus reads and writes data will be described, with reference
to FIGS. 2 and 3.
[0025] As FIG. 2 shows, the optical disk 10 has a number of
concentric tracks. Each track consists of eight segments Sg.sub.0
to Sg.sub.7. As shown in FIG. 3, each segment Sg.sub.i is composed
of an address area Ad.sub.ai and a read/write area RW.sub.ai. The
address area Ad.sub.ai has embossed pits. The read/write area
RW.sub.ai has spiral grooves G and a spiral land L. The spiral
grooves G and the spiral land L are wobbling at a predetermined
frequency. The wobbling is used as synchronization data.
[0026] As shown in FIG. 2, the read/write area RW.sub.ai are
grouped, forming n+1 zones Z.sub.0 to Z.sub.n arranged from the
innermost track to the outermost rack. In the innermost zone
Z.sub.0, each segment Sg.sub.i has 420 wobble waves. Hence, 3360
wobble waves exist in the innermost track. The grooves G in the
innermost zone Z.sub.0 are, of course, wobbling. In the second
innermost zone Z.sub.i, each segment Sg.sub.i has 426 wobble waves,
six more waves than in the innermost zone Z.sub.0. Thus, 3408
wobble waves exist in the second innermost track. Similarly, each
segment of any zone has six more waves than each zone of the
immediately inner zone, and each zone has 48 more waves than the
immediately outer zone. The wobble frequency at the innermost part
of each zone Z.sub.i is the same as that at the innermost part of
any other zone. In the outermost zone Z.sub.n, each segment
Sg.sub.i has 420+6 n wobble waves, and 3360+48 n wobble waves exist
in the outermost track.
[0027] In each zone Z.sub.i, the address areas Ad.sub.n are
arranged in the CAV fashion, that is, in the radial direction of
the optical disk 10. In each address area Ada, the address data of
the grooves G is written as groove header GH, and the address data
of the land L is written as land header LH. The address areas Ada
are formed at the same density in the innermost part of each zone
Z.sub.i.
[0028] How the optical disk apparatus records and reproduces data
on and from the optical disk 10 will be now described. To record
data on the disk 10, an AV system 21 supplies a record command and
an MPEG2 image bit stream to the optical disk apparatus. In the
optical disk apparatus, the system controller 13 receives the
record command. The system controller 13 acquires the address data
from the address DEC TG 14 and controls the servo circuit 18, which
performs a seek operation of the OP head 11. More precisely, the
servo circuit 18 moves the head 11 to a desired address position on
the optical disk 10. Meanwhile, the ECC circuit 17 effects ECC
encoding on the bit stream to be recorded on the optical disk 10.
The modem circuit 16 modulates the bit stream thus encoded. The RW
circuit 15 performs recording compensation and dives the laser
diode LD incorporated in the OP head 11, whereby the bit stream
modulated is recorded on the optical disk 10 at the timing
designated by the address DEC TG 14.
[0029] To reproduce the data from the optical disk 10, the AV
system 21 supplies a reproduce command to the system controller 13.
The system controller 13 receives address data from the address DEC
TG 14 and controls the servo circuit 18, which carries out a seek
operation of the OP head 11. The OP head 11 is thereby moved to a
desired address position on the optical disk 11. The RW circuit 15
receives a signal reproduced from the OP head 11 and supplies the
same to the modem circuit 16. The modem circuit 16 demodulates the
signal, thereby reproducing the bit stream. The bit stream
reproduced is supplied to the ECC 17. ECC 17 corrects errors in the
bit stream and decodes the bit stream, reproducing the image bit
stream. The image bit stream, thus reproduced, is supplied to the
AV system 21.
[0030] In the course of recording data and reproducing data, the
wobble circuit 12 detects a wobble signal from the signal supplied
from the OP head 11. The wobble circuit 12 generates a sync signal
from the wobble signal. The sync signal is supplied to the address
DEC TG 14.
[0031] When the wobble circuit 12 extracts the wobble signal from
the signal read by the OP head 11 and generates the sync signal
from the wobble signal, it holds the PLL circuit (not shown) that
generates the sync signal for any part of the wobble signal that
has not been normally extracted. FIG. 4 shows the wobble circuit 12
in detail.
[0032] As shown in FIG. 4, the wobble circuit 12 comprises a
band-pass filter (BPF) 22, a comparator 23, a phase comparator 24,
a low-pass filter (LPF) 25, a voltage-controlled oscillator (VCO)
26, and a frequency divider 27. The wobble signal is obtained from
a so-called "push-pull (pp) signal." To be more specific, the
push-pull signal is made to pass through the BPF 22. A
wobble-frequency component, i.e., a wobble signal, is thus
extracted from the push-pull signal. The comparator 23 converts the
wobble signal to a binary signal, The binary signal is input, as a
PLL signal, to the phase comparator 24. The phase comparator 24
compares the PLL signal with a PLL reference signal, generating a
phase-difference signal, when a wobble enable signal is set at "H"
(high level). While the wobble enable signal remains at "L" (low
level), the output of the phase comparator 24 is held. The
phase-difference signal is input via the LPF 25 to the VCO 26. The
VCO 26 generates a clock signal, the frequency of which accords
with the input voltage.
[0033] The frequency divider 27 divides the frequency of the clock
signal, thus generating a PLL reference signal that has the same
frequency as the wobble signal. A phase-locked loop (PLL) is
thereby formed, which makes nil the phase difference between the
PLL input signal and the PLL reference signal. The clock signal is
supplied as a sync signal to the address-decoding timing generator
14. The generator 14 generates a timing signal from the sync
signal.
[0034] FIG. 5 illustrates how a wobble signal is generated during
the data-recording and how a synchronization signal is generated
from the wobble signal. In other words, FIG. 5 shows how the
optical disk apparatus operates in the recording mode when the
write signal is at "H". As shown in FIG. 5, the wobble signal has
its waveform distorted when the operating mode changes from the
reproducing mode to the recording mode, and vice versa. The
waveform of the PLL input signal is distorted, too, as the
operating mode is switched. The wobble enable signal is set at "L"
when the operating mode changes from the reproducing mode to the
recording mode, and vice versa, as is illustrated in FIG. 5. Note
that the system controller 13 generates the wobble enable
signal.
[0035] When the wobble signal is distorted in its waveform, the PLL
is held. This prevents the waveform distortion of the wobble signal
from influencing the recording of data.
[0036] How a wobble signal is generated during the track jump and
how a synchronization signal is generated from the wobble signal
will be described, with reference to FIG. 6.
[0037] As shown in FIG. 6, the push-pull signal is affected by the
track jump. The PLL input signal cannot form a binary waveform that
wobbles adequately. To generate a sufficiently wobbling signal, the
wobble enable signal is set at "L" in the track jump area, as is
illustrated in FIG. 6. The PLL is thereby held, thereby preventing
the track jump from affecting the push-pull signal.
[0038] FIG. 7 shows how a wobble signal is generated from the
address data area and how a synchronization signal is generated
from the wobble signal.
[0039] As shown in FIG. 7, there is no wobble signal in the address
data area. The PLL input signal is inevitably influenced in the
address data area. To prevent the PLL input signal from being
influenced, the wobble enable signal is set at "L" in the address
data area as is illustrated in FIG. 7. The PLL is thereby held,
thus preventing the PLL input signal from being influenced in the
address data area.
[0040] FIG. 8 shows another type of a wobble circuit 12, which
generates a synchronization signal from a wobble signal.
[0041] The wobble signal is generated from the push-pull (pp)
signal. More specifically, the push-pull signal is made to pass
through the band-pass filter (BPF) 22. The BPF 22 extracts a
wobble-frequency component from the push-pull signal, thus
generating a wobble signal. The comparator 23 converts the wobble
signal to a binary signal. The binary signal is input to the gate
28, to which a wobble enable signal is input, too. When the wobble
enable signal is at "H", the gate 28 outputs the binary signal. The
gate 28 does not output the binary signal when the wobble enable
signal is at "L". The signal output from the gate 28 is the PLL
input signal that is input to the phase comparator 29. The phase
comparator 29 compares the PLL input signal with a PLL reference
signal in terms of phase, generating a phase-difference signal.
[0042] The phase-difference signal is input via the LPF 25 to the
VCO 26. The VCO 26 generates a clock signal, the frequency of which
accords with the input voltage.
[0043] The frequency divider 27 divides the frequency of the clock
signal, thus generating a PLL reference signal that has the same
frequency as the wobble signal. The phase comparator 29 is, for
example, an exclusive OR (EOR) circuit, forming a phase-locked loop
(PLL) that provides a phase difference of 90.degree. between the
PLL input signal and the PLL reference signal. Even if no PLL input
signal is supplied to the phase comparator 29, the output of the
comparator 29 passes through the LPF 25 and reduces to nil. The PLL
is thereby held. The clock signal, i.e., the output of the VCO 26,
is used as a sync signal to generate a timing signal.
[0044] FIG. 9 explains how the wobble circuit of FIG. 8 generates a
wobble signal and how a synchronization signal is generated from
the wobble signal.
[0045] More precisely, FIG. 9 illustrates the recording mode the
apparatus takes when the write signal is at "H". As shown in FIG.
9, the wobble signal is distorted in waveform when the operating
mode is switched from the reproducing mode to the recording mode.
The wobble enable signal is therefore set at low level when the
mode is switched from the reproducing mode to the recording mode
and when the mode is switched from the recording mode to the
reproducing mode. As shown in FIG. 9, the PLL input signal is at
low level, while the wobble enable signal remains at "L", thus
holding the PLL. This prevents the PLL input signal from being
influenced by the waveform distortion of the wobble signal, which
occurs in the recording mode.
* * * * *