U.S. patent application number 09/218681 was filed with the patent office on 2001-11-15 for control information recording method and apparatus, information recording method and apparatus, and information record medium.
Invention is credited to INOUE, AKIYOSHI, KURODA, KAZUO, OHIRA, HIROYUKI, SUZUKI, TOSHIO, TANIGUCHI, SHOJI.
Application Number | 20010040845 09/218681 |
Document ID | / |
Family ID | 11583816 |
Filed Date | 2001-11-15 |
United States Patent
Application |
20010040845 |
Kind Code |
A1 |
TANIGUCHI, SHOJI ; et
al. |
November 15, 2001 |
CONTROL INFORMATION RECORDING METHOD AND APPARATUS, INFORMATION
RECORDING METHOD AND APPARATUS, AND INFORMATION RECORD MEDIUM
Abstract
By the control information recording method, control information
to control at least one of recording and reproducing operations of
record information on an information record medium is recorded onto
a guide track of the information record medium. The control
information recording method is provided with the steps of:
generating a control information timing signal one after another at
an interval corresponding to a length of a control information unit
equal to an N (N:predetermined integer not less than 2) multiple of
a length of a record information unit of the record information;
and recording the control information onto the guide track of the
information record medium, on the basis of a timing corresponding
to the control information timing signal.
Inventors: |
TANIGUCHI, SHOJI;
(TOKOROZAWA-SHI, JP) ; INOUE, AKIYOSHI;
(TOKOROZAWA-SHI, JP) ; KURODA, KAZUO;
(TOKOROZAWA-SHI, JP) ; SUZUKI, TOSHIO;
(TOKOROZAWA-SHI, JP) ; OHIRA, HIROYUKI;
(NAKAKOMA-GUN, JP) |
Correspondence
Address: |
GERALD LEVY
KANE DALSIMER SULLIVAN KURUCZ
LEVY EISELE AND RICHARD
711 THIRD AVENUE 20TH FLOOR
NEW YORK
NY
10017
|
Family ID: |
11583816 |
Appl. No.: |
09/218681 |
Filed: |
December 22, 1998 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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09218681 |
Dec 22, 1998 |
|
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08780288 |
Jan 8, 1997 |
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Current U.S.
Class: |
369/47.2 ;
G9B/27.027; G9B/27.033; G9B/7.005; G9B/7.034 |
Current CPC
Class: |
G11B 2020/1274 20130101;
G11B 27/3027 20130101; G11B 27/24 20130101; G11B 2020/1287
20130101; G11B 2020/1292 20130101; G11B 7/0037 20130101; G11B
2220/218 20130101; G11B 2220/2562 20130101; G11B 20/10 20130101;
G11B 20/1217 20130101; G11B 2020/1265 20130101; G11B 2220/2554
20130101; G11B 7/00745 20130101 |
Class at
Publication: |
369/47.2 |
International
Class: |
G11B 007/005 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 12, 1996 |
JP |
P08-4421 |
Claims
what is claimed is:
1. A method of recording, onto a guide track of an information
record medium, control information to control at least one of
recording and reproducing operations of record information on said
information record medium, said method comprising the steps of:
generating a control information timing signal one after another at
an interval corresponding to a length of a control information unit
equal to an N (N:predetermined integer not less than 2) multiple of
a length of a record information unit of the record information;
and recording the control information onto the guide track of said
information record medium, on the basis of a timing corresponding
to the control information timing signal.
2. A method according to claim 1, wherein the control information
is pre-information including at least address information
indicative of a record position on said information record medium
of the record information, the record information unit is one
synchronization frame, and in said generating step, the control
information timing signal is generated by doubling said one
synchronization frame.
3. A method according to claim 1, wherein the control information
has a length along the guide track equal to an integer multiple of
a unit length corresponding to a pit interval along the guide track
defined by a recording format of the record information, for a
record pit to be formed on said information record medium in
correspondence with the record information in the recording
operation, and in said recording step, the control information is
recorded for each control information unit, by a control
information pit having a length shorter along the guide track than
the shortest pit length of the record pit.
4. A method according to claim 1, wherein in said generating step,
the control information timing signal is generated at such an
interval that positions of the control information recorded on
adjacent turns of the guide track are not on a straight line
perpendicular to the guide track on said information record
medium.
5. A method according to claim 1, wherein said generating step
comprises the steps of: generating an even timing signal, as a
first kind of the control information timing signal corresponding
to an even numbered record information unit in a record information
unit row comprising M (M:predetermined integer not less than 2)
record information units; generating an odd timing signal, as a
second kind of the control information timing signal corresponding
to an odd numbered record information unit in the record
information unit row; and selecting one of the even and odd timing
signals such that positions of the control information recorded on
adjacent turns of the guide track are not on a straight line
perpendicular to the guide track on said information record medium,
in said recording step, the control information is recorded onto
the guide track of said information record medium, on the basis of
a timing corresponding to the selected one of the even and odd
timing signals.
6. A method according to claim 5, wherein said selecting step
comprises the steps of: storing the selected one of the even and
odd timing signals for one turn of the guide track; and selecting
one of the even and odd timing signals for another turn of the
guide track next to said one turn, on the basis of the stored one
of the even and odd timing signals.
7. An apparatus for recording, onto a guide track of an information
record medium, control information to control at least one of
recording and reproducing operations of record information on said
information record medium, said apparatus comprising: a generating
unit for generating a control information timing signal one after
another at an interval corresponding to a length of a control
information unit equal to an N (N:predetermined integer not less
than 2) multiple of a length of a record information unit of the
record information; and a recording unit for recording the control
information onto the guide track of said information record medium,
on the basis of a timing corresponding to the control information
timing signal.
8. An apparatus according to claim 7, wherein the control
information is pre-information including at least address
information indicative of a record position on said information
record medium of the record information, the record information
unit is one synchronization frame, and said generating unit
generates the control information timing signal by doubling said
one synchronization frame.
9. An apparatus according to claim 7, wherein the control
information has a length along the guide track equal to an integer
multiple of a unit length corresponding to a pit interval along the
guide track defined by a recording format of the record
information, for a record pit to be formed on said information
record medium in correspondence with the record information in the
recording operation, and said recording unit records the control
information for each control information unit, by a control
information pit having a length shorter along the guide track than
the shortest pit length of the record pit.
10. An apparatus according to claim 7, wherein said generating unit
generates the control information timing signal at such an interval
that positions of the control information recorded on adjacent
turns of the guide track are not on a straight line perpendicular
to the guide track on said information record medium.
11. An apparatus according to claim 7, wherein said generating unit
comprises: a first generating device for generating an even timing
signal, as a first kind of the control information timing signal
corresponding to an even numbered record information unit in a
record information unit row comprising M (M:predetermined integer
not less than 2) record information units; a second generating
device for generating an odd timing signal, as a second kind of the
control information timing signal corresponding to an odd numbered
record information unit in the record information unit row; and a
selecting device for selecting one of the even and odd timing
signals such that positions of the control information recorded on
adjacent turns of the guide track are not on a straight line
perpendicular to the guide track on said information record medium,
said recording unit records the control information onto the guide
track of said information record medium, on the basis of a timing
corresponding to the selected one of the even and odd timing
signals.
12. An apparatus according to claim 11, wherein said selecting
device comprises: a memory for storing the selected one of the even
and odd timing signals for one turn of the guide track; and a
selector for selecting one of the even and odd timing signals for
another turn of the guide track next to said one turn, on the basis
of the stored one of the even and odd timing signals.
13. An information record medium comprising: a substrate having an
information record surface; an information record track formed on
said information record surface in a spiral or coaxial shape, for
recording record information; a guide track formed on said
information record surface in parallel to said information record
track, for guiding a light beam, which is to perform at least one
of recording and reproducing operations of the record information,
to said information record track; and a control information for
controlling at least one of the recording and reproducing
operations, recorded on said guide track at an interval
corresponding to a length of a control information unit equal to an
N (N:predetermined integer not less than 2) multiple of a length of
a record information unit of the record information.
14. An information record medium according to claim 13, wherein the
control information is pre-information including at least address
information indicative of a record position on said information
record surface of the record information, the record information
unit is one synchronization frame, and the pre-information is
recorded on said guide track for each pre-information unit, which
is obtained by doubling said one synchronization frame.
15. An information record medium according to claim 13, wherein the
control information has a length along the guide track equal to an
integer multiple of a unit length corresponding to a pit interval
along the guide track defined by a recording format of the record
information, for a record pit to be formed on said information
record surface in correspondence with the record information in the
recording operation, and the control information is recorded for
each control information unit, by a control information pit having
a length shorter along the guide track than the shortest pit length
of the record nit.
16. An information record medium according to claim 13, wherein
positions of the control information recorded on adjacent turns of
the guide track are not on a straight line perpendicular to the
guide track on said information record surface.
17. An information record medium according to claim 13, further
comprising the record information, which is recorded on said
information record track by a record pit formed in correspondence
with the record information in the recording operation and which
has a synchronization signal for achieving a synchronization in the
reproducing operation, wherein the control information has a length
along the guide track equal to an integer multiple of a unit length
corresponding to a pit interval along the guide track defined by a
recording format of the record information, the control information
is recorded for each control information unit, by a control
information pit having a length shorter along the guide track than
the shortest pit length of the record pit, and positions of the
control information and the synchronization signal recorded on
adjacent turns of the guide track and the information record track
are on a straight line perpendicular to the guide track on said
information record surface.
18. A method of recording record information onto information
record medium, said information record medium comprising: a
substrate having an information record surface; an information
record track formed on said information record surface in a spiral
or coaxial shape, for recording the record information; a guide
track formed on said information record surface in parallel to said
information record track, for guiding a light beam, which is to
perform at least one of recording and reproducing operations of the
record information, to said information record track; and a control
information for controlling at least one of the recording and
reproducing operations, recorded on said guide track at an interval
corresponding to a length of a control information unit equal to an
N (N:predetermined integer not less than 2) multiple of a length of
a record information unit of the record information, said method
comprising the steps of: detecting the control information from
said information record medium; generating the record information
on the basis of a record signal inputted from the external such
that a synchronization signal is added to each record information
unit in correspondence with the detected control information; and
recording the generated record information onto the information
record track.
19. An apparatus for recording record information onto information
record medium, said information record medium comprising: a
substrate having an information record surface; an information
record track formed on said information record surface in a spiral
or coaxial shape, for recording the record information; a guide
track formed on said information record surface in parallel to said
information record track, for guiding a light beam, which is to
perform at least one of recording and reproducing operations of the
record information, to said information record track; and a control
information for controlling at least one of the recording and
reproducing operations, recorded on said guide track at an interval
corresponding to a length of a control information unit equal to an
N (N:predetermined integer not less than 2) multiple of a length or
a record information unit of the record information, said apparatus
comprising: a detecting unit for detecting the control information
from said information record medium; a record information
generating unit for generating the record information on the basis
of a record signal inputted from the external such that a
synchronization signal is added to each record information unit in
correspondence with the detected control information; and a
recording unit for recording the generated record information onto
the information record track.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention is related with a control information
recording method and apparatus for recording in advance, onto an
information record medium of WO (Write Once) type (hereafter,
referred to as a DVD-R (Digital Video or Versatile
Disk-Recordable)) among information record media whose recording
densities are dramatically improved over conventional CDs (Compact
Disks) and the like represented by the DVD, control information
such as address information, a synchronization information etc.
(hereafter, referred to as "pre-information") required to record
and reproduce the substantial record information such as video
information and audio information to and from the DVD-R. The
present invention is also related with an information recording
method and apparatus for recording the record information onto the
DVD-R while reproducing the pre-information from the DVD-R on which
the pre-information has been already recorded.
[0003] 2. Description of the Related Art
[0004] In an information record medium such as a WO type postscript
optical disk and the like, the pre-information for a position
retrieval at a time of writing the record information is recorded
in advance onto the information record medium at a pre-format stage
in manufacturing the information record medium. As a method of
pre-formatting this pre-information, an information record track (a
groove track or a land track) for recording the record information
is wobbled in a form of a wave so as to record the pre-information.
Alternatively, a pre-pit is formed on a portion different from a
portion where the record information is recorded on the information
record track, so as to record the pre-information.
[0005] However, in a case of the pre-format of the pre-information
by the wobbling, the information record track itself is swung to
the right and left relative to a rotation direction of the
information record medium on the basis of a wobbling signal. This
results in a problem that a C/N ratio (Carrier to Noise ratio) is
poor because of a restriction in a modulation degree of the
wobbling signal (wobbling amplitude) due to a relation to an
adjacent information record track. Further, considering an
interference resulting from the adjacent information record track
since the adjacent information record tracks are close to each
other by the wobbling, it is difficult to make a track pitch
narrow. This results in a problem of limitation in improvement of
the recording density.
[0006] On the other hand, in a case of the pre-format of the
pre-information by the pre-pit, since the pre-pit is formed on the
information record track, the recordable amount of the substantial
record information is reduced by the amount of the formed pre-pit.
This results in a problem of a poor utilization efficiency of a
disk record surface.
SUMMARY OF THE INVENTION
[0007] Then, the present invention is proposed from the viewpoint
of the above mentioned problems. It is therefore an object of the
present invention to provide a method of and an apparatus for
recording control information (i.e. pre-information) to an
information record medium, a method of and an apparatus for
recording record information to the information record medium to
which the control information is recorded in advance, and the
information record medium to which the control information is
recorded in advance, which can improve a recording density of the
record information and an accuracy in the reproduction of the
record information.
[0008] The above object of the present invention can be achieved by
a first method of recording, onto a guide track of an information
record medium, control information to control at least one of
recording and reproducing operations of record information on the
information record medium. The first method is provided with the
steps of: generating a control information timing signal one after
another at an interval corresponding to a length of a control
information unit equal to an N (N:predetermined integer not less
than 2) multiple of a length of a record information unit of the
record information; and recording the control information onto the
guide track of the information record medium, on the basis of a
timing corresponding to the control information timing signal.
[0009] According to the first method of the present invention, the
control information timing signal is generated one after another at
the interval corresponding to the length of the control information
unit equal to the N multiple of the length of the record
information unit. Then, the control information is recorded onto
the guide track of the information record medium, on the basis of
the timing corresponding to the control information timing signal.
Thus, as compared with a case that the control information is
recorded for all of the record information unit, the amount of the
control information recorded on the whole information record medium
can be reduced by the factor of 1/N, and that the recording density
of the record information can be certainly improved. Further, it is
possible to easily form a recording layer with a desirable
thickness on the information record medium to which the control
information has been recorded in advance.
[0010] In one aspect of the first method, the control information
is pre-information including at least address information
indicative of a record position on the information record medium of
the record information, the record information unit is one
synchronization frame, and in the generating step, the control
information timing signal is generated by doubling said one
synchronization frame.
[0011] According to this aspect of the first method, since the
control information timing signal is generated by doubling said one
synchronization frame, the pre-information is recorded once per two
synchronization frames. Thus, as compared with a case that the
pre-information is recorded for all of the synchronization frames,
the amount of the pre-information recorded on the whole information
record medium can be reduced by half, and that the recording
density of the record information can be certainly improved.
Further, it is possible to easily form a recording layer with a
desirable thickness on the information record medium to which the
pre-information has been recorded in advance.
[0012] In another aspect of the first method, the control
information has a length along the guide track equal to an integer
multiple of a unit length corresponding to a pit interval along the
guide track defined by a recording format of the record
information, for a record pit to be formed on the information
record medium in correspondence with the record information in the
recording operation, and in the recording step, the control
information is recorded for each control information unit, by a
control information pit having a length shorter along the guide
track than the shortest pit length of the record pit.
[0013] According to this aspect of the first method, since the
control information is recorded for each control information unit,
by the control information pit having the length shorter than the
shortest pit length of the record pit, the control information is
recorded to have a pit length different from any pit length of the
record information. Thus, it is possible to easily separate the
record information and the control information from each other in
the reproducing operation.
[0014] In another aspect of the first method, in the generating
step, the control information timing signal is generated at such an
interval that positions of the control information recorded on
adjacent turns of the guide track are not on a straight line
perpendicular to the guide track on the information record
medium.
[0015] According to this aspect of the first method, since the
control information timing signal is generated at such an interval
that positions of the control information recorded on adjacent
turns of the guide track are not on the straight line perpendicular
to the guide track on the information record medium, it is possible
to prevent the control information on the adjacent turns of the
guide track from interfering or leaking to each other in the
recording or reproducing operation.
[0016] In another aspect of the first method, the generating step
is provided with the steps of: generating an even timing signal, as
a first kind of the control information timing signal corresponding
to an even numbered record information unit in a record information
unit row comprising M (M:predetermined integer not less than 2)
record information units; generating an odd timing signal, as a
second kind of the control information timing signal corresponding
to an odd numbered record information unit in the record
information unit row; and selecting one of the even and odd timing
signals such that positions of the control information recorded on
adjacent turns of the guide track are not on a straight line
perpendicular to the guide track on the information record medium.
In the recording step, the control information is recorded onto the
guide track of the information record medium, on the basis of a
timing corresponding to the selected one to the even and odd timing
signals.
[0017] According to this aspect of the first method, in the
generating step, the even timing signal corresponding to the even
numbered record information unit in the record information unit row
is generated, while the odd timing signal corresponding to the odd
numbered record information unit in the record information unit row
is generated. At this time, one of the even and odd timing signals
is selected such that positions of the control information recorded
on adjacent turns of the guide track are not on the straight line
perpendicular to the guide track on the information record medium.
Then, in the recording step, the control information is recorded
onto the guide track of the information record medium, on the basis
of the timing corresponding to the selected one of the even and odd
timing signals. Thus, since the control information is recorded
only in the even or odd numbered record information unit, as
compared with a case that the control information is recorded for
all of the record information unit, the amount of the control
information recorded on the whole information record medium can be
reduced by about half, and that the recording density of the record
information can be certainly improved. Further, it is possible to
easily form a recording layer with a desirable thickness on the
information record medium to which the control information has been
recorded in advance. Furthermore, it is possible to prevent the
control information on the adjacent turns of the guide track from
interfering or leaking to each other in the recording or
reproducing operation.
[0018] In this aspect of the first method, the selecting step may
be preferably provided with the steps of: storing the selected one
of the even and odd timing signals for one turn of the guide track;
and selecting one of the even and odd timing signals for another
turn of the guide track next to said one turn, on the basis of the
stored one of the even and odd timing signals.
[0019] In this case, at first, the selected one of the even and odd
timing signals is stored for one turn of the guide track. Later,
one of the even and odd timing signals is newly selected for
another turn of the guide track next to said one turn, on the basis
of the stored one of the even and odd timing signals. Thus, it is
possible, by use of a relatively simple construction, to select one
of the even and odd timing signals such that positions of the
control information recorded on adjacent turns of the guide track
are not on the straight line perpendicular to the guide track on
the information record medium.
[0020] The above object of the present invention can be also
achieved by a first apparatus for recording, onto a guide track of
an information record medium, control information to control at
least one of recording and reproducing operations of record
information on the information record medium. The first apparatus
is provided with: a generating unit for generating a control
information timing signal one after another at an interval
corresponding to a length of a control information unit equal to an
N (N:predetermined integer not less than 2) multiple of a length of
a record information unit of the record information; and a
recording unit for recording the control information onto the guide
track of the information record medium, on the basis of a timing
corresponding to the control information timing signal.
[0021] According to the first apparatus of the present invention,
the control information timing signal is generated, by the
generating unit, one after another at the interval corresponding to
the length of the control information unit equal to the N multiple
of the length of the record information unit. Then, the control
information is recorded, by the recording unit, onto the guide
track of the information record medium, on the basis of the timing
corresponding to the control information timing signal. Thus, in
the same manner as the above described first method of the present
invention, the amount of the control information can be reduced,
and that the recording density of the record information can be
improved. Further, it is possible to easily form the recording
layer with the desirable thickness.
[0022] In one aspect of the first apparatus, the control
information is pre-information including at least address
information indicative of a record position on the information
record medium of the record information, the record information
unit is one synchronization frame, and the generating unit
generates the control information timing signal by doubling said
one synchronization frame.
[0023] According to this aspect of the first apparatus, in the same
manner as the first method of the present invention, the amount of
the pre-information can be reduced, and that the recording density
can be improved. Further, it is possible to easily form the
recording layer with the desirable thickness.
[0024] In another aspect of the first apparatus, the control
information has a length along the guide track equal to an integer
multiple of a unit length corresponding to a pit interval along the
guide track defined by a recording format of the record
information, for a record pit to be formed on the information
record medium in correspondence with the record information in the
recording operation, and the recording unit records the control
information for each control information unit, by a control
information pit having a length shorter along the guide track than
the shortest pit length of the record pit.
[0025] According to this aspect of the first apparatus, in the same
manner as the first method of the present invention, it is possible
to easily separate the record information and the control
information from each other in the reproducing operation.
[0026] In another aspect of the first apparatus, the generating
unit generates the control information timing signal at such an
interval that positions of the control information recorded on
adjacent turns of the guide track are not on a straight line
perpendicular to the guide track on the information record
medium.
[0027] According to this aspect of the first apparatus, in the same
manner as the first method of the present invention, it is possible
to prevent the control information on the adjacent turns of the
guide track from interfering or leaking to each other in the
recording or reproducing operation.
[0028] In another aspect of the first apparatus, the generating
unit is provided with: a first generating device for generating an
even timing signal, as a first kind of the control information
timing signal corresponding to an even numbered record information
unit in a record information unit row comprising M (M:predetermined
integer not less than 2) record information units; a second
generating device for generating an odd timing signal, as a second
kind of the control information timing signal corresponding to an
odd numbered record information unit in the record information unit
row; and a selecting device for selecting one of the even and odd
timing signals such that positions of the control information
recorded on adjacent turns of the guide track are not on a straight
line perpendicular to the guide track on the information record
medium. The recording unit records the control information onto the
guide track of the information record medium, on the basis of a
timing corresponding to the selected one of the even and odd timing
signals.
[0029] According to this aspect of the first apparatus, in the same
manner as the first method of the present invention, the amount of
the control information can be reduced by about half, and that the
recording density can be certainly improved. Further, it is
possible to easily form the recording layer with the desirable
thickness. Furthermore, it is possible to prevent the control
information on the adjacent turns of the guide track from
interfering or leaking to each other in the recording or
reproducing operation.
[0030] In this aspect of the first apparatus, the selecting device
may he preferably provided with: a memory for storing the selected
one of the even and odd timing signals for one turn of the guide
track; and a selector for selecting one of the even and odd timing
signals for another turn of the guide track next to said one turn,
on the basis of the stored one of the even and odd timing
signals.
[0031] In this case, in the same manner as the first method of the
present invention, it is possible, by use of a relatively simple
construction, to select one of the even and odd timing signals such
that positions of the control information recorded on adjacent
turns of the guide track are not on the straight line perpendicular
to the guide track on the information record medium.
[0032] The above object of the present invention can be also
achieved by an information record medium provided with: a substrate
having an information record surface; an information record track
formed on the information record surface in a spiral or coaxial
shape, for recording record information; a guide track formed on
the information record surface in parallel to the information
record track, for guiding a light beam, which is to perform at
least one of recording and reproducing operations of the record
information, to the information record track; and a control
information for controlling at least one of the recording and
reproducing operations, recorded on the guide track at an interval
corresponding to a length of a control information unit equal to an
N (N:predetermined integer not less than 2) multiple of a length of
a record information unit of the record information.
[0033] According to the information record medium of the present
invention, as compared with an information record medium in which
the control information is recorded for all of the record
information unit, the amount of the control information recorded on
the whole information record medium can be reduced by the factor of
1/N, and that the recording density of the record information can
be certainly improved. Further, it is possible to easily form a
recording layer with a desirable thickness on the information
record medium to which the control information has been recorded in
advance.
[0034] In one aspect of the information record medium, the control
information is pre-information including at least address
information indicative of a record position on the information
record surface of the record information, the record information
unit is one synchronization frame, and the pre-information is
recorded on the guide track for each pre-information unit, which is
obtained by doubling said one synchronization frame.
[0035] According to this aspect of the information record medium,
as compared with an information record medium in which the
pre-information is recorded for all of the synchronization frames,
the amount of the pre-information recorded on the whole information
record medium can be reduced by half, and that the recording
density of the record information can be certainly improved.
Further, it is possible to easily form a recording layer with a
desirable thickness on the information record medium to which the
pre-information has been recorded in advance.
[0036] In another aspect of the information record medium, the
control information has a length along the guide track equal to an
integer multiple of a unit length corresponding to a pit interval
along the guide track defined by a recording format of the record
information, for a record pit to be formed on the information
record surface in correspondence with the record information in the
recording operation, and the control information is recorded for
each control information unit, by a control information pit having
a length shorter along the guide track than the shortest pit length
of the record pit.
[0037] According to this aspect of the information record medium,
it is possible to easily separate the record information and the
control information from each other in the reproducing
operation.
[0038] In another aspect of the information record medium,
positions of the control information recorded on adjacent turns of
the guide track are not on a straight line perpendicular to the
guide track on the information record surface.
[0039] According to this aspect of the information record medium,
it is possible to prevent the control information on the adjacent
turns of the guide track From interfering or leaking to each other
in the recording or reproducing operation.
[0040] In another aspect of the information record medium, the
information record medium is further provided with the record
information, which is recorded on the information record track by a
record pit formed in correspondence with the record information in
the recording operation and which has a synchronization signal for
achieving a synchronization in the reproducing operation, wherein
the control information has a length along the guide track equal to
an integer multiple of a unit length corresponding to a pit
interval along the guide track defined by a recording format of the
record information, the control information is recorded for each
control information unit, by a control information pit having a
length shorter along the guide track than the shortest pit length
of the record pit, and positions of the control information and the
synchronization signal recorded on adjacent turns of the guide
track and the information record track are on a straight line
perpendicular to the guide track on the information record
surface.
[0041] According to this aspect of the information record medium,
since the control information is recorded to have a pit length
different from any pit length of the record information, it is
possible to easily separate the record information and the control
information from each other in the reproducing operation. Further,
the positions of the control information and the synchronization
signal recorded on adjacent turns of the guide track and the
information record track are on the straight line perpendicular to
the guide track, it is possible to easily obtain the timing
relationship between the record information and the control
information, and easily separate them from each other in the
reproducing operation.
[0042] The above object of the present invention can be also
achieved by a second method to recording record information onto
the above described information record medium of the present
invention. The second method is provided with the steps of:
detecting the control information from the information record
medium; generating the record information on the basis of a record
signal inputted from the external such that a synchronization
signal is added to each record information unit in correspondence
with the detected control information; and recording the generated
record information onto the information record track.
[0043] According to the second method of the present invention, in
advance of actually recording the record information, the control
information is firstly detected from the information record medium.
Secondly, the record information is generated on the basis of a
record signal inputted from the external such that the
synchronization signal is added to each record information unit in
correspondence with the detected control information. Finally, the
generated record information is recorded onto the information
record track. Thus, on the information record medium which has been
recorded by the second method, the position of the synchronization
signal on the information record track and the position of the
control information on the guide track are adjacent to each other,
so that it is possible to easily separate the record information
and the control information from each other in the detection of the
control signal and the reproduction of the record information.
[0044] The above object of the present invention can be also
achieved by a second apparatus for recording record information
onto the above described information record medium of the present
invention. The second apparatus is provided with: a detecting unit
for detecting the control information from the information record
medium; a record information generating unit for generating the
record information on the basis of a record signal inputted from
the external such that a synchronization signal is added to each
record information unit in correspondence with the detected control
information; and a recording unit for recording the generated
record information onto the information record track.
[0045] According to the second apparatus of the present invention,
in advance of actually recording the record information, the
control information is firstly detected, by the detecting unit,
from the information record medium. Secondly, the record
information is generated, by the record information generating
unit, on the basis of a record signal inputted from the external
such that the synchronization signal is added to each record
information unit in correspondence with the detected control
information. Finally, the generated record information is recorded,
by the recording unit, onto the information record track. Thus, in
the same manner as the second method of the present invention, it
is possible to easily separate the record information and the
control information from each other in the detection of the control
signal and the reproduction of the record information.
[0046] As described above, according to the present invention, it
is possible to prevent a direct current (DC) element from being
changed in the detected or reproduced signal of the information
record medium, and also possible to protect the jitter due to the
unstableness of the pit shape from being generated in the detected
or reproduced signal, so that the detection of the control
information and the reproduction of the record information can be
accurately performed while the recording density of the record
information can be certainly improved.
[0047] The nature, utility, and further features of this invention
will be more clearly apparent from the following detailed
description with respect to a preferred embodiment of the invention
when read in conjunction with the accompanying drawings briefly
described below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0048] FIG. 1 is a schematic appearance view showing an example of
the DVD-R in which a pre-pit is formed on a land track;
[0049] FIG. 2 is a diagram showing a recording format of the
pre-information and the record information;
[0050] FIG. 3 is a block diagram showing a schematic configuration
of a cutting machine as an embodiment of the present invention;
[0051] FIG. 4 is a block diagram showing a schematic configuration
of a pre-format encoder of the embodiment;
[0052] FIG. 5 is a block diagram showing schematic configurations
of a frame signal generator and an ODD/EVEN judging gate signal
generator of the embodiment;
[0053] FIG. 6A is a timing chart showing an EVEN frame signal and
an ODD frame signal in the pre-format encoder;
[0054] FIG. 6B is a timing chart showing an operation of a judging
device in the pre-format encoder;
[0055] FIG. 6C is a timing chart showing operations of an AND
circuit and a delay flip-flop circuit in the pre-format
encoder;
[0056] FIG. 7 is a timing chart showing operations of the frame
signal generator and the ODD/EVEN judging gate signal
generator;
[0057] FIG. 8A is at timing chart showing an operation of a
synchronization pattern generator in the pre-format encoder;
[0058] FIG. 8B is a timing chart showing an operation of a
synchronization data switching signal generator in the pre-format
encoder;
[0059] FIG. 9 is a block diagram showing a schematic configuration
of an information recording apparatus as another embodiment of the
present invention;
[0060] FIG. 10 is a block diagram showing schematic configurations
of an optical pick-up and a pre-pit signal detector of the
embodiment;
[0061] FIG. 11A is a schematic sectional view of showing a shape of
the pre-pit;
[0062] FIG. 11B is a graph of showing wave forms of an RF signal
and a tangential push-pull signal;
[0063] FIG. 12A is a flow chart showing an operation of a CPU of
the embodiment;
[0064] FIG. 12B is a flow chart of showing an operation of an 8-16
encoder of the embodiment; and
[0065] FIG. 13 is a plan view of a record surface of the DVD-R on
which the record information is recorded by the embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0066] Preferred embodiments of the present invention are explained
with reference to the drawings.
[0067] (I) Embodiment of Control Information Recording
Apparatus
[0068] At first, an embodiment of a cutting machine for forming a
pre-pit corresponding to pre-information, as one example of a
control information recording apparatus, will be explained with
reference to FIGS. 1 to 8. An embodiment of the DVD-R, as an
information record medium, in which the pre-pit is formed by the
cutting machine is also described in the following explanation of
the embodiment of the cutting machine.
[0069] At first, a structure of the DVD-R in which the pre-pit is
formed by the cutting machine of this embodiment described later is
explained with reference to FIG. 1.
[0070] In FIG. 1, a DVD-R 1 is a pigment type DVD-R, which has a
pigment film 5 and to which information can be written only one
time. A groove track 2 as an information record track and a land
track 3 as a guide track for guiding a light beam LB, such as a
laser beam and the like as a reproduction light or a record light,
to the groove track 2 are formed in the DVD-R 1 by the cutting
machine described later. The DVD-R 1 is also provided with a
protection layer 7 for protecting them and a gold deposition film 6
for reflecting the light beam LB at a time of reproducing the
recorded information. The pre-pit 4 corresponding to the
pre-information is formed on this land track 3 by the cutting
machine described later. This pre-pit 4 is formed in advance before
the DVD-R 1 is shipped. It is noted here that the "land" track and
the "groove" track are defined relative to each other as shown in
FIG. 1, and the track of either one type may be defined as the land
track while the track of the other type is defined as the groove
track.
[0071] When recording the record information (i.e. the substantial
record information, such as the video information, the audio
information and the like, to be inherently recorded other than the
pre-information), the pre-information is obtained, in advance of
actually recording the record information, by detecting this
pre-pit 4 by an information recording apparatus described later.
Based on it, an optimum output of the light beam LB as the record
light and other recording parameters are set. Further, address
information and the like indicative of a position on the DVD-R 1,
at which each record information is to be recorded, are obtained.
The record information is recorded on the corresponding record
position on the basis of this address information.
[0072] When recording the record information, the light beam LB is
irradiated such that at center thereof coincides with a center of
the groove track 2. Then, a record information pit corresponding to
the record information is formed on the groove track 2, and
accordingly the record information is recorded. At this time, a
size of a light spot SP is set such that it is irradiated to not
only the groove track 2 but also the land track 3, as shown in FIG.
1. The pre-information is obtained by detecting the pre-pit 4 by
means of a tangential push-pull method described later, by using a
portion of reflection light of the light spot SP partially
irradiated to the land track 3.
[0073] Next, a recording format of the pre-information recorded by
the cutting machine of the embodiment is explained with reference
to FIG. 2, before actually explaining the cutting machine of the
embodiment.
[0074] As shown in FIG. 2, the pre-information of the embodiment is
recorded for each synchronization frame (SYNC frame) as an
information unit. Further, one recording sector as an information
unit row is formed by 26 synchronization frames. Further, one ECC
(Error Correcting Code) block is formed by 16 recording sectors.
One synchronization frame has a length equal to 1488 times (1488T)
of the unit length (hereafter, referred to as "T") corresponding to
a pit interval defined by the recording format at a time of
recording the record information.
[0075] The pre-information is recorded at a top portion with a
length of 14T in each of the synchronization frames. In the present
embodiment, the pre-information is recorded only on the
synchronization frames having even numbers (hereafter, referred to
as EVEN frames) or the synchronization frames having odd numbers
(hereafter, referred to as ODD frames), in one recording sector.
The recorded pre-information is classified into synchronization
pre-information and data pre-information. Among them, the
synchronization pre-information is recorded as a top
pre-information in each of the recording sectors (i.e., the 0th
frame for the EVEN SYNC, and the 1st frame for the ODD SYNC). The
synchronization pre-information recorded on the EVEN frame (EVEN
SYNC pre-information) and the synchronization pre-information
recorded on the ODD frame (ODD SYNC pre-information) are recorded
by different patterns, as shown in FIG. 2. It is possible to read
out these patterns at a time of recording the later described
record information to thereby judge whether the pre-information is
recorded on the EVEN frame or the ODD frame.
[0076] On the other hand, the data pre-information is dissipated
into a plurality of synchronization frames and recorded thereon. In
one synchronization frame, the data pre-information corresponding
to [1] is recorded by a length of 2T (i.e., the unit of the
pre-information is 2T), as shown in FIG. 2.
[0077] In FIG. 2, in the recording sector 0, the pre-information is
recorded on the EVEN frame (EVEN SYNC pre-information). In the
recording sector 1, the pre-information is recorded on the ODD
frame (ODD SYNC pre-information).
[0078] Further, the record information, which is recorded on the
basis of the pre-information detected by the information recording
apparatus described later, has the format similar to the recording
format shown in FIG. 2. At this time, in the record information,
the substantial record data, such as the video information, the
audio information and the like, are recorded on positions other
than the top portion with 14T , in one synchronization frame. In
the pre-information, no information is recorded on the positions
other than the top portion with 14T, in one synchronization
frame.
[0079] Next, the cutting machine in accordance with the embodiment
for forming, as shown in FIG. 1, the pre-pit 4 having the recording
format shown in FIG. 2 is explained with reference to FIGS. 3 to
8.
[0080] At first, a configuration of the cutting machine of the
embodiment is explained with reference to FIGS. 3 to 5. The cutting
machine shown in FIGS. 3 to 5 is intended to fabricate a stamper
disk for mass-producing the DVD-R 1, in which the pre-pit 4 is
formed and thereby the pre-information is recorded in accordance
with the present invention.
[0081] The whole configuration of the cutting machine is firstly
explained with reference to FIG. 3.
[0082] As shown in FIG. 3, a cutting machine C of the embodiment is
provided with: a data generator 20 for generating a data
pre-information S.sub.PP up to be recorded; a parallel/serial (P/S)
convertor 21 for parallel/serial-converting the data
pre-information S.sub.PP; a pre-format encoder 22 for generating a
record pre-information S.sub.R to form the pre-pit 4 by the
recording format shown in FIG. 2 on the basis of the data
pre-information S.sub.PP; a clock signal generator 23 for
outputting a clock signal CLK (a period (cycle) is assumed to be
the above mentioned T) used in the pre-formatting to the pre-format
encoder 22; a laser generator 24 for emitting a light beam L.sub.G
to form the groove track 2 shown in FIG. 1 to a substrate of the
DVD-R 1 and for emitting a light beam L.sub.L to form the land
track 3 and the pre-pit 4 shown in FIG. 1; a light modulator 25 for
modulating the emitted light beam L.sub.L on the basis of a record
pre-information S.sub.R; an objective lens 26 for collecting the
light beams L.sub.G and L.sub.L on the stamper disk; a spindle
motor 29 for rotating the stamper disk; a rotation detector 30 for
detecting a rotation number of the stamper disk; a rotation servo
circuit 31 for servo-controlling a rotation of the stamper disk on
the basis of the detected rotation number and for outputting one
rotation detection signal Ss one time for each rotation of the
stamper disk to the pre-format encoder 22; a carriage unit 32 for
carrying in a radial direction of the stamper disk the spindle
motor 29 relative to the stamper disk corresponding to the rotation
of the stamper disk, in order to form the spiral groove track 2 and
the spiral land track 3; a position detector 33 for detecting a
position of the carriage unit 32; and a carriage servo circuit 34
for servo-controlling a movement of the carriage unit 32 on the
basis of the position of the carriage unit 32 detected by the
position detector 33. Here, the laser generator 24 is provided with
an emitting device 24G for emitting the light beam L.sub.G and an
emitting device 24L for emitting the light beam L.sub.L. Although
the light beam L.sub.L is modulated by the light modulator 25 on
the basis of the record pre-information S.sub.R, the light beam
L.sub.G is irradiated to the stamper disk by a DC (direct current)
driving device (not shown) while always keeping a constant light
strength. Further, the light beam L.sub.L to form the land track 3
and the pre-pit 4 and the light beam L.sub.G to form the groove
track 2 are irradiated such that irradiation positions are
gradually shifted in the radial direction of the stamper disk, and
accordingly they simultaneously form the concentrically spiral land
track 3 and groove track 2.
[0083] On the other hand, the stamper disk is provided with a glass
substrate 27 as a main body of the stamper disk, and a resist (e.g.
photo-sensitive material) 28 for forming the pre-pit 4 coated on
the glass substrate 27.
[0084] Incidentally, in the above mentioned configuration, one
example of a recording means is constituted by the laser generator
24, the light modulator 25 and the objective lens 26.
[0085] Next, a detailed configuration of the pre-format encoder 22
is explained with reference to FIG. 4.
[0086] As shown in FIG. 4, the pre-format encoder 22 is provided
with: a frame signal generator 40, as one example of a control
information timing signal generating means, an even number control
information timing signal generating means and an odd number
control information timing signal generating means, for outputting
an EVEN frame signal S.sub.E corresponding to the EVEN frame and an
ODD frame signal So corresponding to the ODD frame, in accordance
with the timing of a frame signal indicating each synchronization
frame shown in FIG. 2, on the basis of the inputted clock signal
CLK, and for outputting an EVEN frame count signal S.sub.EC
outputted by an EVEN frame counter described later that is reset
each time the EVEN frame signal S.sub.E corresponding to one EVEN
frame is generated; an ODD/EVEN judging gate signal generator 41
for outputting a gate signal S.sub.G to judge whether the
synchronization frame for forming the pre-pit 4 to be recorded
during a term corresponding to one round in the stamper disk is set
to the EVEN frame or the ODD frame, on the basis of the clock
signal CLK and one rotation detection signal Ss; a judging device
42, as one example of at selecting means, for outputting a judgment
signal S.sub.J to judge whether the synchronization frame on which
the pre-pit 4 is to be recorded is set to the EVEN frame or the ODD
frame, on the basis of the EVEN frame signal S.sub.g, the gate
signal S.sub.G and one rotation detection signal Ss; a switch 43,
as one example of a selecting means, for selectively switching and
outputting the EVEN frame signal S.sub.E or the ODD frame signal
So, on the basis of the judgment signal S.sub.J; an AND circuit 44
for calculating a logical product of the EVEN frame signal S.sub.E
or the ODD frame signal So outputted by the switch 43 and the data
pre-information S.sub.PP outputted by the parallel/serial convertor
21 (FIG. 3) to thereby output a logical product signal S.sub.A; a
synchronization pattern generator 45 for outputting a
synchronization signal S.sub.Y corresponding to either one of a
synchronization pattern in the synchronization pre-information to
be recorded on the EVEN frame or a synchronization pattern in the
synchronization pre-information to be recorded on the ODD frame, by
using the judgment signal S.sub.J, on the basis of the EVEN frame
signal S.sub.E or the ODD frame signal So outputted by the switch
43, and for outputting a data latch pulse S.sub.L of controlling a
delay amount in a delay flip-flop circuit 47 described later: a
synchronization/data switching signal generator 46 for outputting a
synchronization/data switching signal Sc to switch between the
synchronization pre-information and the data pre-information, on
the basis of the EVEN frame signal S.sub.E or the ODD frame signal
So outputted by the switch 43; the delay flip-flop circuit 47 for
outputting a delay logical product signal S.sub.AD in which the
logical product signal S.sub.A is delayed by a term of 2T, on the
basis of the data latch pulse S.sub.L and the logical product
signal S.sub.A; a switch 48 for switching between the delay logical
product signal S.sub.AD and the synchronization signal S.sub.Y,
based on the synchronization/data switching signal Sc to thereby
output as the record pre-information S.sub.R. In the above
mentioned configuration, the switch 43 is normally switched to a
side of the EVEN frame signal S.sub.E. Further, the switch 48 is
normally switched to a side of the delay logical product signal
S.sub.AD.
[0087] Next, detailed configurations of the frame signal generator
40 and the ODD/EVEN judging gate signal generator 41 are explained
with reference to FIG. 5.
[0088] As shown in FIG. 5, the frame signal generator 40 is
provided with: an ODD frame counter 50 for measuring (counting) an
elapsed time from a timing at which the ODD frame signal So is
generated, on the basis of the clock signal CLK, to thereby output
an ODD frame count signal S.sub.OC; an EVEN frame counter 51 for
measuring an elapsed time from a timing at which the EVEN frame
signal S.sub.E is generated, on the basis of the clock signal CLK,
to thereby output an EVEN frame count signal S.sub.EC; a decoder 52
for outputting, as the ODD frame signal So, a pulse with a length
of 2T, at a time of outputting a next ODD frame signal So, on the
basis of the ODD frame count signal S.sub.OCoutputted by the ODD
frame counter 50; and a decoder 53 for outputting, as the EVEN
frame signal S.sub.E, a pulse with a length of 2T, at a time of
outputting a next EVEN frame signal S.sub.E, on the basis of the
EVEN frame count signal S.sub.EC outputted by the EVEN frame
counter 51.
[0089] On the other hand, as shown in FIG. 5, the ODD/EVEN judging
gate signal generator 41 is provided with: a latch circuit 60, as
one example of a memory means, for latching a value of the EVEN
frame signal S.sub.EC at this time, each time one rotation
detection signal Ss is inputted (in other words, each time the
stamper disk is rotated one time), on the basis of the EVEN frame
count signal S.sub.EC and one rotation detection signal Ss; a gate
counter 61 for time-measuring while being reset to the same value
and by the same period as the EVEN frame counter 51, on the basis
of the clock signal CLK and one rotation detection signal Ss and
for outputting a gate count signal S.sub.GC which value is updated
to a value recorded in the latch circuit 60, each time one rotation
detection signal Ss is inputted; and a mono-multi-vibrator (MMD) 62
for outputting a gate signal S.sub.G with a predetermined length,
each time the value of the gate counter 61 becomes maximum and is
reset, on the basis of the gate count signal S.sub.GC.
[0090] In the cutting machine C having the above mentioned
configuration, an operation thereof is next explained with
reference to timing charts shown in FIGS. 6A to 8.
[0091] At first, an operation of the frame signal generator 40 for
generating the ODD frame signal So and the EVEN frame signal
S.sub.E is explained with reference to FIG. 6A.
[0092] As shown in FIG. 6A, in case of the frame signal, a pulse is
generated at an interval of one synchronization frame length of
1488T, while in case of the ODD frame signal So, a pulse with a
length of each 2T is generated at an interval equal to two times of
the frame signal from a timing corresponding to a first
synchronization frame. This pulse of the ODD frame signal So is
continuously generated by measuring a time corresponding to 2976T
(=1488T.times.2) from the timing of the first synchronization
frame, by the ODD frame counter 50, and by repeating the generation
of the pulse with the length of 2T by the decoder 52, each time the
above mentioned time elapses.
[0093] On the other hand, in case of the EVEN frame signal S.sub.g,
a pulse with a length of each 2T is generated at an interval equal
to two times of the frame signal from a timing corresponding to a
0th synchronization frame. Similarly to the case of the ODD frame
signal So, this EVEN frame signal S.sub.E is continuously generated
by measuring a time corresponding to 2976T from the timing of the
0th synchronization frame, by the EVEN frame counter 51, and by
repeating the generation of the pulse with the length of 2T by the
decoder 53, each time the above mentioned time elapses. At this
time, the EVEN frame count signal S.sub.FC outputted by the EVEN
frame counter 51 is outputted to the latch circuit 60 within the
ODD/EVEN judging gate signal generator 41.
[0094] Next, an operation of the ODD/EVEN judging gate signal
generator 41 is explained with reference to FIG. 7.
[0095] As shown in FIG. 7, when the EVEN frame count signal
S.sub.EC to generate the EVEN frame signal S.sub.E is generated in
the frame signal generator 40 in correspondence with the frame
signal, the latch circuit 60 latches (stores) the value of the EVEN
frame count signal S.sub.EC at a timing when one rotation detection
signal Ss is inputted.
[0096] At this time, the gate counter 61 time-measures while being
reset to the same value and by the same period as the EVEN frame
counter 51 on the basis of the clock signal CLK. Each time one
rotation detection signal Ss is inputted, the gate counter 61 is
updated to a value stored in the latch circuit 60 at that time, and
it repeats the time-measurement from its value. That is, the gate
counter 61 repeats the same operation as the EVEN frame counter 51
in the immediately previous recording operation which is one
rotation (of the stamper disk) prior to the present operation. In
other words, position information of the pre-pit 4 recorded on the
EVEN frame in the previous recording operation, which is one
rotation prior to the present operation, is included in the value
of the gate counter 61.
[0097] Each time this value of the gate counter 61 (i.e. the signal
S.sub.SG) becomes maximum and is reset, the mono-multi-vibrator 62
generates a pulse signal as the gate signal S.sub.G. Thus, the
position information of the pre-pit 4 recorded on the EVEN frame in
the previous recording operation one rotation prior to the present
operation is also included in this gate signal S.sub.G. A pulse
width of this gate signal S.sub.G is assumed to be a pulse width of
(14T+.DELTA.), which is the sum of 14T (this is the length of the
synchronization pre-information) and a length corresponding to an
increment .DELTA. in a length of the land track 3 corresponding to
one rotation of the stamper disk, which is increased by one
rotation of the stamper disk (more actually,
.DELTA.=2.times..pi..times. (a track pitch between the land tracks
3).
[0098] Next, an operation of the judging device 42 (FIG. 4) is
explained with reference to FIG. 6B.
[0099] As shown in FIG. 6B, in the judging device 42, if the EVEN
frame signal S.sub.E is within a range of the gate signal S.sub.H,
the judgment signal S.sub.J as shown in FIG. 6B is outputted so as
to switch the switch 43, which is normally switched to the side of
the EVEN frame signal S.sub.g, to the side of the ODD frame signal
So, at a rising timing of the EVEN frame signal S.sub.E.
Accordingly, the switch 43 outputs the ODD frame signal So to the
AND circuit 44.
[0100] Thus, normally, since the EVEN frame signal S.sub.E is
outputted to the AND circuit 44, the pre-pit 4 is formed at a
position of the EVEN frame, on the basis of the EVEN frame signal
S.sub.g, and thereby the pre-information is recorded. However, in
the judging device 42, if the EVEN frame signal S.sub.E enters
within the range of the gate signal S.sub.G, that is, if the
position of the pre-pit 4, which has been recorded in the previous
recording operation one rotation prior to the present operation,
(its information is included in the gate signal S.sub.G) is close
to the present position (e.g. the position of the EVEN frame) of
the pre-pit in the present rotation (e.g. within the range of
(14T+.DELTA.) with respect to the position of- the pre-pit 4 one
rotation prior to the present position), the judgment signal
S.sub.J is outputted so as to switch the switch 43 to the side of
the ODD frame signal So, and thereby the pre-pit 4 in the present
rotation is formed at the position of the ODD frame.
[0101] When an action of one rotation under the condition that the
pre-pit 4 is recorded on the position of the ODD frame is detected
by one rotation detection signal Ss, in a rotation after that, the
judgment signal S.sub.J to switch the switch 43 to the side of the
EVEN frame signal S.sub.E is outputted by the judging device 42, so
as to again form the pre-pit 4 on the position of the EVEN
frame.
[0102] Next, operations of the AND circuit 44 and the delay
flip-flop circuit 47 are explained with reference to FIG. 6C.
[0103] The AND circuit 44 calculates a logical product of the EVEN
frame signal S.sub.E or the ODD frame signal So outputted by the
switch 43 and the data pre-information S.sub.PP outputted by the
parallel/serial convertor 21 to thereby output the logical product
signal S.sub.A with a pulse width of 2T. This is intended to
resolve the data pre-information S.sub.PP by each bit to thereby
record only the data pre-information S.sub.PP of one bit
(corresponding to "1") (refer to FIG. 2) having a pulse width of 2T
on one synchronization frame.
[0104] The delay flip-flop circuit 47 delays the logical product
signal S.sub.AD by a time of 2T, on the basis of the latch data
pulse S.sub.L from the synchronization pattern generator 40, to
thereby generate a delay logical product signal S.sub.AD. After
that, this delay logical product signal S.sub.AD is outputted to
the switch 48 as the data pre-information to be recorded.
[0105] The reason why the delay flip-flop circuit 47 delays the
logical product signal S.sub.A is described below. That is, the
synchronization signal (with a length of 14T) of the record signal
is recorded on the groove track 2 adjacent to the pre-pit, in a
record information device described later. However, if the logical
product signal S.sub.A is not delayed at this time, there may be a
case that a rising timing of the synchronization signal of the
record signal and a rising timing of the pre-information are equal
or close to each other. In this case, it is difficult to separate
and reproduce the pre-information and the synchronization signal.
Further, the delay amount of the logical product signal S.sub.A is
defined as 2T, since a margin must be considered in order to
prevent that the rising timing of the synchronization signal and
the rising timing of the pre-information be close to each other
because of an effect of a jitter at a time of recording the record
signal and the like.
[0106] Next, an operation of the synchronization pattern generator
45 (FIG. 4) is explained with reference to FIG. 8A.
[0107] In a case that the judgment signal S.sub.J outputted by the
judging device 42 is a signal indicative of the EVEN frame signal
S.sub.g, the synchronization pattern generator 45 generates the
EVEN synchronization pre-information having a synchronization
pattern, as shown in FIG. 8A, corresponding to the EVEN frame
signal S.sub.E outputted by the switch 43 to thereby output as the
synchronization signal S.sub.Y to the switch 48.
[0108] On the other hand, in a case that the judgment signal
S.sub.J outputted by the judging device 42 is a signal indicative
of the ODD frame signal So, the synchronization pattern generator
45 generates the ODD synchronization pre-information having a
synchronization pattern, as shown in FIG. 8A, corresponding to the
ODD frame signal So outputted by the switch 43 to thereby output as
the synchronization signal S.sub.Y to the Switch 48.
[0109] In parallel to these operations, the synchronization pattern
generator 45 extends the clock signal CLK by a term of 1T to
thereby generate a data latch pulse S.sub.L having a period of 2T,
and outputs it to the delay flip-flop circuit 47 (refer to FIG.
6C).
[0110] Finally, an operation of the synchronization/data switching
signal generator 16 is explained with reference to FIG. 8B.
[0111] As shown in FIG. 8B, in the synchronization/data switching
signal generator 46, in a case that the signal outputted by the
switch 43 is the EVEN frame signal S.sub.g, a synchronization/data
switching signal Sc which is in the "ll" state for a term of 14T
(corresponding to a length of the EVEN synchronization
pre-information) from the rising timing of the 0th EVEN frame
signal S.sub.E is outputted, in order to record the EVEN
synchronization pre-information on a position of the 0th EVEN frame
signal S.sub.g, among the EVEN frames. Accordingly, the switch 48
is switched to a side of the synchronization signal S.sub.Y only
for the term of 14T from the rising timing of the 0th EVEN frame
signal S.sub.E. As a result, the EVEN synchronization
pre-information outputted by the synchronization pattern generator
45 is recorded on a position of the 0th EVEN frame signal
S.sub.E.
[0112] On the other hand, in a case that the signal outputted by
the switch 43 is the ODD frame signal So, a synchronization/data
switching signal Sc which is in the "ll" state for a term of 14T
(corresponding to a length of the ODD synchronization
pre-information) from a rising timing of a first ODD frame signal
So is outputted, in order to record the ODD synchronization
pre-information on a position of the first ODD frame signal So,
among the ODD frames. Accordingly, the switch 48 is switched to the
side of the synchronization signal S.sub.Y only for the term of 14T
from the rising timing of the first ODD frame signal So. As a
result, the ODD synchronization pre-information is recorded on a
position of the first ODD frame signal So.
[0113] With respect to the operations of the cutting machine C of
the embodiment as mentioned above, when concluding the features
thereof, in a case where the position of the pre-pit 4 in the
previous recording operation one rotation prior to the present
operation (which is normally recorded on the position of the EVEN
frame) is close to the position of a pre-pit 4 in a next rotation
(i.e. the present rotation), more actually in a case where it is
judged by the judging device 42 that the EVEN frame signal S.sub.E
in the next rotation enters within the range of the gate signal
S.sub.G including the information of the previous position of the
pre-pit 4 one rotation prior to the present position, the record
pre-information S.sub.R is generated such that the pre-pit 4 in the
next rotation is recorded on the position of the ODD frame signal
So, especially by the operations of the ODD/EVEN judging gate
signal generator 41 and the judging device 45 among the cutting
machine C of the embodiment. Based on it, the light beam L.sub.L is
modulated by the light modulator 25, and thereby the land track 3
including the pre-pit 4 is formed on the DVD-R 1. At this time, the
groove track 2 is formed so as to be located parallel to the land
track 3 by the light beam L.sub.G outputted simultaneously with the
light beam L.sub.L.
[0114] As mentioned above, according to the cutting machine C of
the embodiment, the pre-pit 4 is formed only on the position
corresponding to the EVEN frame or the position corresponding to
the ODD frame, in one rotation of the stamper disk. Thus, as
compared with the case in which the pre-pits 4 are recorded for
every synchronization frame, it is possible to reduce the number of
the pre-pits 4 throughout the DVD-R 1. Further, when forming the
pigment film 5 (refer to FIG. 1) to form the groove track 2 for the
DVD-R 1 on which the pre-pit 4 is formed, the pigment film 5 can
have a layer with a predetermined thickness necessary for the
design.
[0115] When explaining this effect, typically, in order to speedily
and firstly detect the pre-information at a time of forming the
pre-pit 4 onto the land track 3, all the pre-pits 4 are formed
collectively at a single position on a predetermined portion of the
land track 3, and then the pre-pits 4 are repeatedly formed on the
land track 3 many times at a predetermined interval, and thereby
the pre-information is recorded.
[0116] When actually manufacturing the DVD-R 1, the groove track 2,
the land track 3 and the necessary pre-pit 4 are formed at first.
After that, material of the pigment film 5 is coated on the DVD-R 1
by means of a spin coating method, for example. Then, this is
treated by a baking (heating) process and the like to thereby form
a recording layer having the necessary film thickness.
[0117] However, in the method of forming the necessary pre-pit 4
collectively at the single position on the land track 3 as
mentioned above, a top surface of the pre-pit 4 (in a case that an
irradiation direction of the light beam is upward) is normally
flush with a top surface of the groove track 2 (refer to FIG. 1).
Thus, the material of the pigment film 5 which should inherently
stay on the groove track 2 flows into the pre-pit 4. Therefore, it
is impossible to form the pigment film 5 having the predetermined
film thickness necessary for the design for the groove track 2.
Then, in a case that the pigment film 5 having the predetermined
film thickness can not be formed, when reproducing the record
information recorded by the pit formed on the pigment film 5, the
direct current (DC) element in a reproduction signal may he
changed, and the jitter may he generated because of unstableness of
a shape of the pit. This results in a problem that the record
information cannot be reproduced accurately.
[0118] In contrast with this, as mentioned above, according to the
cutting machine C of the embodiment, as compared with the case in
which the pre-pits 4 are recorded for every synchronization frame,
it is possible to reduce the number of the pre-pits 4, and further,
only the pre-pit 4 with the length of 2T is formed in one
synchronization frame. Thus, when forming the pigment film 5 for
the DVD-R 1 on which the pre-pit 4 is formed, the pigment film 5
can have the layer with the predetermined thickness necessary for
the design. As a result, it is possible to prevent the above
mentioned direct current (DC) element from being changed and
protect the jitter due to the unstableness of the pit shape from
being generated, to thereby reproduce the record information
accurately.
[0119] Further, according to the cutting machine C of the
embodiment, in a case that the position of the pre-pit 4 recorded
on the position of the EVEN frame in the previous recording
operation one rotation prior to the present operation is close to
the position of the pre-pit 4 in the next rotation (i.e. the
present rotation), the pre-pit 4 is formed on the position of the
ODD frame in the next rotation. After further making one rotation
in that state, the pre-pit 4 is formed on the original position of
the EVEN frame. Thus, the positions of the pre-pits 4 do not
overlap with each other in the guide tracks 3 adjacent to each
other. Then, when detecting the pre-information at a time of
recording the record information as described later, ashen reading
out the pre-information on one guide track 3, it is possible to
prevent the leakage of the pre-information in the guide tracks 3
adjacent to each other and possible to read out the pre-information
accurately.
[0120] At this time, the gate signal S.sub.G is set to have a pulse
width equal to a length of (14T+.DELTA.) including an increment
.DELTA. of a length corresponding to one round of the land track 3
for each rotation in the stamper disk. Thus, the positions of the
pre-pits 4 on the land tracks 3 adjacent to each other are never
close to each other, due to a change of a radial position on the
stamper disk. As a result, the positions of the pre-pits 4 on the
land tracks 3 adjacent to each other can be set to positions which
are not located on the same straight line in the radial direction,
in any portion on the stamper disk.
[0121] Moreover, since storing the frame signal used at a time of
recording the pre-information in one of the guide tracks 3 to
thereby output the frame signal at a time of recording the
pre-information in the guide tracks 3 adjacent to each other, the
position of the pre-pit 4 of one of the guide tracks 3 can be made
different from the position of the adjacent guide track 3, under
the simple configuration.
[0122] (II) Embodiment of Information Recording Apparatus
[0123] Next, an embodiment of the information recording apparatus
will be explained with reference to FIGS. 9 to 13.
[0124] At first, a whole configuration of the information recording
apparatus of the embodiment is explained with reference to FIG.
9.
[0125] As shown in FIG. 9, an information recording apparatus R of
the embodiment is provided with: an optical pickup 70, as one
example of a record information recording means, which contains a
laser diode, an objective lens described later, a polarization beam
splitter, a light detector and the like that are not shown, for
reading out the pre-pit 4 of the DVD-R 1, on which the guide tracks
3, the pre-pits 4 and the groove tracks 2 are formed by the above
mentioned cutting machine C, to thereby detect the pre-information
Sp, and for further emitting the light beam LB as the record light
to record the record information such as the video information, the
audio information and the like; a pre-pit signal detector 71 for
detecting a pre-pit signal (i.e. pre-information Sp) from a
reproduction signal detected by the pickup 70 by a tangential
push-pull method described later; a wave form shaping device 72 for
wave-form-shaping the detected pre-information Sp (including the
synchronization pre-information and the data pre-information); a
PLL (Phase Locked Loop) circuit 73 for phase-comparing a standard
data transferring clock outputted by a standard data transferring
clock generator 74 with the detected pre-pit signal to thereby
output a data transferring clock in synchronization with the
pre-information Sp; a spindle motor 75 for rotating the DVD-R l; a
PLL circuit 76 for phase-comparing the detected pre-pit signal with
a rotation number detection signal outputted by the spindle motor
75 and then outputting a spindle error signal to the spindle motor
75 to thereby servo-control the rotation number of the spindle
motor 75 to a predetermined number; a synchronization separator 77
for separating a synchronization pre-information S.sub.SY (a
synchronization pattern is the EVEN synchronization pre-information
or the ODD synchronization pre-information shown in FIG. 2) from
the pre-information Sp as the detected pre-pit signal; an 8-16
encoder 78, as one example of a generating means, which has a gate
78A opened by the synchronization pre-information S.sub.SY
outputted by the synchronization separator 77 for 8-16-modulating
an input signal S.sub.D as an externally inputted record signal to
be recorded based on the data transferring clock outputted by the
PLL 73, generating a record information stream S.sub.DS and then
outputting it when the gate 78A is opened; a serial/parallel (S/P)
convertor 79 for serial/parallel-converting the detected
pre-information Sp, and outputting an address information S.sub.ADD
in the pre-information Sp when requested by an interrupt signal
S.sub.I from a CPU 80 described later; the CPU 80 for outputting
the interrupt signal S.sub.I when a writing order of the record
information is inputted by an external record/reproduction
switching signal, and outputting a preparation signal S.sub.RD
based on the address information S.sub.ADD; a pulse controller 81
for pulse-controlling and outputting the record information stream
S.sub.DS which is outputted by the 8-16 encoder 78 and whose delay
amount is slightly adjusted; and an LD (LASER Diode) driver 82 for
outputting a drive signal S.sub.DR on the basis of the
pulse-controlled record information stream S.sub.DS to thereby
drive the laser diode of the optical pickup 70 so as to output the
light beam LB as the record light.
[0126] Next, the above mentioned tangential push-pull method used
to detect the pre-information Sp in the information recording
apparatus R is explained, with detailed configurations of the
pickup 70 and the pre-pit signal detector 71, with reference to
FIGS. 10 and 11.
[0127] The tangential push-pull method refers to a push pull method
in a rotation direction of the DVD-R 1. This is a method of
reproducing the above mentioned pre-information, on the basis of a
differential signal of two partial detectors in the light detector,
in which a reflection light from the light spot SP by the light
beam LB formed on the land track 3 of the DVD-R 1 is detected by
the two partial detectors divided by a division line optically
vertical to a moving direction (i.e. the rotation direction of the
disk) of the pre-pit 4.
[0128] That is, more actually, as shown in FIG. 10, in the optical
pickup 70, the light beam LB as the record light (the reproduction
light to the pre-pit 4) generated by the laser diode and the like
(not shown) is reflected on the polarization beam splitter 91, and
collected on the groove track 2 and the land track 3 of the DVD-R 1
(refer to FIG. 1) by the objective lens 90. The reflection light of
the light beam LB, which is modulated by the pre-pit 4 and in which
a polarization surface is rotated by the reflection on the DVD-R 1,
is transmitted through the polarization beam splitter 91 by the
rotation of the polarization surface, and is irradiated to
respective light-receiving surfaces of the light detector 92, which
is divided into two partial detectors 92A and 92B by the division
line optically vertical to the rotation direction of the DVD-R 1,
and then it is detected. Light-receiving-outputs of the respective
partial detectors 92A and 92B (in the following explanation, the
outputs of the respective partial detectors are indicated by
symbols A and B) are subtracted by a subtractor 93 constituting the
pre-pit signal detector 71. A differential signal (A-B) thereof is
outputted to the wave form shaping device 72 as the reproduction
signal (pre-information Sp).
[0129] Next, the generation of the differential signal (tangential
push-pull signal) (A-B) by means of the light detector 92 and the
subtractor 93 is explained with reference to FIGS. 11A and 11B.
[0130] In FIG. 11A, when the light detector 92 receives the
reflection light from the pre-pit 4 having a shape indicative of a
section view in the rotation direction of the DVD-R 1, the
light-receiving outputs of the partial detectors 92A and 92B are
outputted from the respective partial detectors 92A and 92B as RF
(Radio Frequency) signals A (front signal) and B (rear signal)
whose phases are different from each other, as shown in FIG. 11B,
on the basis of positional deviations thereof. Then, the subtractor
93 determines a difference between the respective RF signals.
Accordingly, the differential signal (tangential push-pull signal)
(A-B) is generated as shown in FIG. 11B.
[0131] Next, an operation of the information recording apparatus R
for recording the record information on the basis of the
pre-information Sp detected by the tangential push-pull method is
explained with reference to a flow chart shown in FIG. 12.
[0132] At first, an operation as for the CPU 80 as a center is
explained by using FIG. 12A.
[0133] As shown in FIG. 12A, in the CPU 80, it is firstly judged
whether or not the writing order of the record information is
inputted from the exterior (Step S1). If the writing order is not
inputted (Step S1; NO), the process is repeated. If the writing
order is inputted (Step S1; YES), the interrupt signal S.sub.I is
next outputted to the serial/parallel convertor 79 in order to
obtain the address information S.sub.ADD corresponding to the
record information to be recorded (Step S2). Incidentally, in
parallel to the processes at the steps S1 and S2, the DVD-R 1 is
rotated by the spindle motor 75. Corresponding to this rotation,
the light beam LB is irradiated. Accordingly, the pre-information
Sp is obtained from the pre-pit 4 formed on the land track 3 of the
DVD-R 1.
[0134] When the interrupt signal S.sub.I is outputted at the step
S2, it is judged whether or not the address information S.sub.ADD
inputted by the serial/parallel convertor 79 corresponding to the
interrupt signal S.sub.i is a predetermined address information
S.sub.ADD corresponding to the record information to be recorded
(Step S3). If it is not the predetermined address information
S.sub.ADD (Step S3; NO), the process is returned to the step S2, in
order to output the interrupt signal S.sub.I to thereby obtain
another address information S.sub.ADD again.
[0135] On the other hand, if the obtained address information
S.sub.ADD is the predetermined address information S.sub.ADD (Step
S3; YES), the preparation signal S.sub.RD is outputted (Step S4),
in order to make the 8-16 encoder 75 prepare for an output of the
record information stream S.sub.DS, since the predetermined address
information S.sub.ADD is obtained. Then, the process is ended.
[0136] Next, an operation of the 8-16 encoder 78 to which the
preparation signal S.sub.RD is inputted is explained with reference
to FIG. 12B.
[0137] As shown in FIG. 12B, in the 8-16 encoder 78, it is firstly
judged whether or not the preparation signal S.sub.RD is inputted
from the CPU 80 (Step S10). If it is not inputted (Step S10; NO),
the process is repeated until it is inputted. If the preparation
signal S.sub.RD is inputted (Step S10; YES), it is judged whether
or not the synchronization pre-information S.sub.SY in the
pre-information Sp detected from the synchronization separator 77
is inputted, that is, it is judged whether or not the top portion
of the recording sector is detected (Step S11). If it is not
detected (Step S11; NO), the process is returned to the step S10 in
order to wait until a next preparation signal S.sub.RD is inputted.
If the synchronization pre-information S.sub.SY is detected (Step
S11; YES), the time-measurement is performed for one ECC block term
(26 recording sector terms) (Step S13). If the measurement is not
completed (Step S13; NO), the process waits until it is completed.
If it is completed (Step S13; YES), the input signal S.sub.D is
8-16-modulated, and then the gate 78A is opened, and thereby the
output of the record information stream S.sub.DS is started.
Namely, it is started encoding the record signal (Step S14). The
output of the record information stream S.sub.DS is performed on
the basis of the data transferring clock from the PLL circuit 73.
Further, in the record information stream S.sub.DS, the
synchronization signal (with a length of 14T) is added to each top
portion (the position where the pre-pit 4 in the pre-information is
formed) for each synchronization frame. Here, the reason why the
time-measurement is performed for one ECC block term at the steps
S12 and S13 is that it is intended to surely record the record
information from the top portion of the ECC block.
[0138] After the record information stream S.sub.DS is outputted
from the 8-16 encoder 78, the record information stream S.sub.DS is
pulse-controlled by the pulse controller 81. The drive signal
S.sub.DR corresponding to the record information stream S.sub.DS is
outputted by the LD driver 82. The laser diode (not shown) in the
pickup 70 is driven by this drive signal S.sub.DR, and thereby the
light beam LB is emitted. The record information pit corresponding
to the record information stream S.sub.DS is formed on the groove
track 2, and thereby the record information is recorded. In a case
that the input signal S.sub.D is modulated by the 8-16 modulating
method, a length of the record information pit formed on the DVD-R
1 becomes a length from 3T to 14T.
[0139] Here, the synchronization pre-information in the pre-pit 4
and the synchronization signal in the record information coincide
with each other, by the operation (refer to FIG. 12B) in the 8-16
encoder 78. Thus, in one recording sector, the data pre-information
on and after the synchronization pre-information (recorded with the
length of 2T on the top portion of one synchronization frame, as
mentioned above) and the synchronization signal in the record
information are in synchronization with each other. That is, seeing
this on the DVD-R 1 in which a record information pit
P.sub.Dcorresponding to the record information is formed on the
groove track 2, a synchronization signal pit Ps of the record
information is always formed adjacent to the pre-pit 4 as shown in
FIG. 13. FIG. 13 shows a case of reading out the pre-pit 4 adjacent
to an outer circumference side (a right side to a rotation
direction) of the groove track 2 while forming the light spot SP
(refer to FIG. 1) on the groove track 2 with respect to the
rotation direction of the DVD-R 1. Further, a length in the
rotation direction of each of the pre-pits 4 is 2T. This length 2T
is different from any lengths of the record information pits
P.sub.D (3T to 14T) formed by the 8-16 modulation.
[0140] As explained above, according to the information recording
apparatus R of the embodiment, the record information is recorded
such that the synchronization signal is added for each
synchronization frame and further the synchronization signal and
the pre-information are recorded in synchronization with each
other. Thus, the position of the synchronization signal on the
groove track 2 and the position of the pre-pit 4 on the land track
3 are adjacent to each other, on the DVD-R 1 on which both the
pre-information and the record information are recorded. As a
result, at a time of detecting the pre-information or reproducing
the record information, it is possible to easily separate and
reproduce the record information and the pre-information and also
possible to accurately detect the pre-information or reproduce the
record information.
[0141] Moreover, the length (2T) in the rotation direction of the
pre-pit 4 corresponding to the pre-information is different from
any lengths of the record information pits P.sub.D (from 3T to 14T)
corresponding to the record information. As a result, in
reproducing the record information, it is possible to surely
separate and reproduce the pre-information to thereby reproduce the
record information accurately.
[0142] Furthermore, the first 2T term in each pre-information (the
synchronization pre-information or the data pre-information)
recorded on the top portion of the synchronization frame is set to
"L" (refer to FIG. 2) by the operation of the delay flip-flop
circuit 47. As a result, even if the position of the pre-pit 4
corresponding to the pre-information and the position of the
synchronization signal in the record signal are adjacent to each
other, it is possible to detect both of them without a cross talk
between both of them.
[0143] In the above embodiment, the tangential push-pull method is
employed for the detection of the pre-pit 4. Instead, the radial
push-pull method may be employed, in which the reflection light
from the light spot SP formed on the land track 3 is detected by
the two partial detectors divided by a division line optically
parallel (i.e. not vertical) to the moving direction of the pre-pit
4, and the pre-information is reproduced on the basis of a
differential signal of these detectors. According to the radial
push-pull method, it is possible to judge by the polarity of this
differential signal on which side the pre-pit 4 is located with
respect to the two partial detectors, and, even in a condition that
the record information pit P.sub.D is already recorded, the
undesirable influence of the record information pit P.sub.D onto
the detection of the pre-pit 4 can be reduced.
[0144] The invention may be embodied in other specific forms
without departing from the spirit or essential characteristics
thereof. The present invention 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.
* * * * *