U.S. patent application number 09/767544 was filed with the patent office on 2001-09-13 for digital signal recording method and apparatus and recording medium therefor.
This patent application is currently assigned to U.S. Philips Corporation. Invention is credited to Harumatsu, Mitsuo, Higurashi, Seiji, Ohishi, Takeo.
Application Number | 20010021306 09/767544 |
Document ID | / |
Family ID | 24187093 |
Filed Date | 2001-09-13 |
United States Patent
Application |
20010021306 |
Kind Code |
A1 |
Higurashi, Seiji ; et
al. |
September 13, 2001 |
Digital signal recording method and apparatus and recording medium
therefor
Abstract
A format for the recording of trick play signals is proposed in
which trick play segments comprising sync blocks of information of
a trick play signal are recorded in groups of p successive tracks.
At least first and second trick play signals are recorded on the
record carrier. The first trick play signal is meant for
reproduction in a reproduction apparatus at a reproduction speed n1
times the recording speed with which the trick play signals are
recorded on the record carrier. The second trick play signal is
meant for reproduction in the said reproduction apparatus at a
reproduction speed -n1 times the recording speed. The first trick
play signal is recorded using a first head having a first azimuth
angle and the second trick play signal is recorded using a second
write head having a second azimuth angle different from the first
azimuth angle.
Inventors: |
Higurashi, Seiji;
(Fuchu-Shi, JP) ; Ohishi, Takeo; (Yokohama-Shi,
JP) ; Harumatsu, Mitsuo; (Yokohama-Shi, JP) |
Correspondence
Address: |
Corporate Patent Counsel
U.S. Philips Corporation
580 White Plains Road
Tarrytown
NY
10591
US
|
Assignee: |
U.S. Philips Corporation
|
Family ID: |
24187093 |
Appl. No.: |
09/767544 |
Filed: |
January 23, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09767544 |
Jan 23, 2001 |
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09548019 |
Apr 12, 2000 |
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09548019 |
Apr 12, 2000 |
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08623297 |
Mar 28, 1996 |
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6026213 |
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Current U.S.
Class: |
386/208 ;
375/E7.267; 386/323; 386/350; 386/E9.013 |
Current CPC
Class: |
H04N 5/783 20130101;
B65G 47/962 20130101; H04N 7/52 20130101; B65G 43/00 20130101; H04N
9/8042 20130101; B65G 45/10 20130101; B61D 15/08 20130101 |
Class at
Publication: |
386/68 ; 386/74;
386/81 |
International
Class: |
H04N 005/783 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 28, 1995 |
JP |
96179/1995 |
Claims
1. An apparatus for recording a first and a second digital
information signal in slant tracks on a magnetic record carrier,
the apparatus comprising input means for receiving the first and
second digital information signal, signal processing means for
processing the first and second digital signal into first and
second trick play signals respectively, suitable for recording in
the tracks, writing means for writing at a recording speed of the
record carrier, the first and second trick play signals so as to
obtain trick play segments located at specific positions in said
tracks, the writing means comprising at least a first and a second
write head located on a rotatable head drum, the first head having
a gap with a first azimuth angle and the second head having a gap
with a second azimuth angle which is different from the first
azimuth angle, the first digital information signal being meant for
enabling a replay in a reproduction apparatus at a trick play
reproduction speed which equals n1 times the recording speed, the
second digital information signal being meant for enabling a replay
in said reproduction apparatus at a trick play reproduction speed
which equals -n1 times the recording speed, where n1 is a positive
integer unequal to 0 and 1, characterized in that the first and
second trick play signals comprise sync blocks of information of
the first and second digital information signal, respectively, and
that the writing means are adapted to write sync blocks of the
first trick play signal into first trick play segments in tracks on
the record carrier using said first write head, without using said
second write head, and to write sync blocks of the second trick
play signal into second trick play segments in tracks on the record
carrier using said second write head, without using said first
write head. (v=+4.times. and v=-4.times., or v=+12.times. and
v=-12.times., or v=-24.times. and v=+24.times.)
2. Apparatus as claimed in claim 1, characterized in that the
writing means are adapted to write the sync blocks of the first
trick play signal and the sync blocks of the second trick play
signal on the record carrier, so as to enable, during reproduction
at said trick play speed n1 times the recording speed in said
reproduction apparatus, which is provided with reading means for
reading the first and second trick play segments, said reading
means comprising at least a first and a second read head located on
a rotatable head drum, said first read head having a gap with an
azimuth angle substantially equal to said first azimuth angle and
the second read head having a gap with an azimuth angle
substantially equal to said second azimuth angle, the reading of
the first trick play signal from first trick play segments using
said first read head, without using said second read head, and to
enable, during reproduction at said trick play speed -n1 times the
recording speed, the reading of the second trick play signal from
second trick play segments using said second read head, without
using said first read head.
3. Apparatus as claimed in claim 1 or 2, characterized in that
n1=4, 12 or 24.
4. Apparatus as claimed in claim 1, characterized in that the input
means are further adapted to receive a third and a fourth digital
information signal, the signal processing means further being
adapted to process the third and fourth digital signals into a
third and a fourth trick play signal, respectively, suitable for
recording in the tracks, the writing means further being adapted to
write, at said recording speed of the record carrier, the third
trick play signal so as to obtain third trick play segments located
at specific positions in said tracks and to write the fourth trick
play signal so as to obtain fourth trick play segments located at
specific positions in said tracks, the third digital information
signal being meant for enabling a replay in the said reproduction
apparatus at a trick play reproduction speed which equals n2 times
the recording speed, the fourth digital information signal being
meant for enabling a replay in the said reproduction apparatus at a
trick play reproduction speed which equals -n2 times the recording
speed, where n2 is a positive integer unequal to n1 and unequal to
0 and 1, that the third trick play signal comprise sync blocks of
information of the third digital information signal, and that the
writing means are adapted to write sync blocks of the third trick
play signal into third trick play segments using the first write
head, without using said second write head, and that the fourth
trick play signal comprise sync blocks of information of the fourth
digital information signal, and that the writing means are adapted
to write sync blocks of the fourth trick play signal into fourth
trick play segments using the second write head, without using said
first write head.
5. Apparatus as claimed in claim 4, characterized in that the
writing means are adapted to write the sync blocks of the third
trick play signal and the sync blocks of the fourth trick play
signal on the record carrier, so as to enable, during reproduction
at said trick play speed n2 times the recording speed in said
reproduction apparatus, the reading of the third trick play signal
from third trick play segments using said first read head, without
using said second read head, and to enable, during reproduction at
said trick play speed -n2 times the recording speed, the reading of
the fourth trick play signal from fourth trick play segments using
said second read head, without using said first read head.
6. Apparatus as claimed in claim 4, characterized in that the
writing means are adapted to write trick play signals for all
possible trick play speeds in one direction using said first write
head, without using said second write head, and to write trick play
signals for all possible trick play speeds in the direction reverse
to said one direction using said second write head, without using
said first write head.
7. Record carrier obtained with the apparatus as claimed in anyone
of the preceding claims.
8. Method of recording a first and a second digital information
signal in slant tracks on a magnetic record carrier, the method
comprising the steps of receiving the first and second digital
information signal, processing the first and second digital signal
into first and second trick play signals respectively, suitable for
recording in the tracks, writing at a recording speed of the record
carrier, the first and second trick play signals so as to obtain
trick play segments located at specific positions in said tracks
using writing means, the writing means comprising at least a first
and a second write head located on a rotatable head drum, the first
head having a gap with a first azimuth angle and the second head
having a gap with a second azimuth angle which is different from
the first azimuth angle, the first digital information signal being
meant for enabling a replay in a reproduction apparatus at a trick
play reproduction speed which equals n1 times the recording speed,
the second digital information signal being meant for enabling a
replay in said reproduction apparatus at a trick play reproduction
speed which equals -n1 times the recording speed, where n1 is a
positive integer unequal to 0 and 1, characterized in that the
first and second trick play signals comprise sync blocks of
information of the first and second digital information signal,
respectively, and that the writing step comprises writing the sync
blocks of the first trick play signal into first trick play
segments in tracks on the record carrier using said first write
head, without using said second write head, and writing the sync
blocks of the second trick play signal into second trick play
segments in tracks on the record carrier using said write head,
without using said first write head. (v=+4.times. and v=-4.times.,
or v=+12.times. and v=-12.times., or v=-24.times. and v=+24.times.)
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a digital information
signal recording method and recording apparatus and a record
carrier therefor. More specifically this invention relates to a
digital information signal recording method and apparatus for
recording a normal reproduction digital signals and special
reproduction digital signals on a tapeform record carrier by use of
a rotary head, and a record carrier used for the digital
information signal recording method and apparatus.
[0002] In general, digital information signals are recorded in
units of data blocks on and reproduced from a tape-form record
carrier such a magnetic tape by use of a rotary head. In the case
of a trick play reproduction (special reproduction), digital
information signals are reproduced at a speed different from the
speed at which the digital information signals are recorded. During
trick play reproduction, the data recorded for the normal
reproduction is reproduced discontinuously, because of the fact
that the scanning pattern of the rotary head across the tape-form
recording medium is different from the scanning pattern when the
digital signals are reproduced in the normal reproduction mode. It
is thus difficult to obtain the trick play reproduction signals
without any additional processing.
[0003] Therefore, conventionally, there has been known a digital
signal recording method for enabling the special reproduction as
disclosed in Japanese Patent-Laid Open No. 1994-261278. This
teaches that digital trick play signals for the special
reproduction mode are arranged and recorded on tracks on which
normal reproduction digital signals are recorded along the rotary
head scanning pattern that is followed by the rotary head in the
special reproduction mode.
[0004] In such a digital signal recording method, the recording
format of the digital signals recorded on each track of a tape-form
recording medium is kept constant. It is thus impossible to record
digital signals of desired systems in various formats (e.g., such a
format that a plurality of data areas are arranged on a single
track so that digital signals can be recorded and reproduced
independently) by use of a signal apparatus.
[0005] In addition, the digital signals for the normal reproduction
mode and the special reproduction mode are recorded on the
recording medium under mixed conditions. The data rate of the
special reproduction digital signals and the arrangement positions
of the special reproduction digital signals in this case are
different from each other, because of the fact that the recording
formats of the digital signals are different from each other. There
arises a problem in that a circuit for forming the special
reproduction digital signals and a circuit for recording the
special reproduction digital signals at specific positions on the
tape-form recording medium are both complicated in circuit
construction.
SUMMARY OF THE INVENTION
[0006] With these problems in mind, therefore, it is an object of
the present invention to provide a digital information signal
recording method and apparatus and a record carrier used therefor,
by which the normal reproduction digital signals and the special
reproduction digital signals can be recorded in accordance with
mutually different formats under mixed conditions.
[0007] Further, another object of the present invention is to
provide a digital information signal recording method and apparatus
and a record carrier used therefor, by which when the normal
reproduction digital signals and the special reproduction digital
signals are recorded on a recording medium under mixed conditions,
the circuits for forming and recording the special reproduction
digital signals can be simplified in circuit construction.
[0008] To achieve the above-mentioned object, the present invention
provides an apparatus for recording a first and a second digital
information signal in slant tracks on a magnetic record carrier,
the apparatus comprising
[0009] input means for receiving the first and second digital
information signal,
[0010] signal processing means for processing the first and second
digital signal into first and second trick play signals
respectively, suitable for recording in the tracks,
[0011] writing means for writing at a recording speed of the record
carrier, the first and second trick play signals so as to obtain
trick play segments located at specific positions in said tracks,
the writing means comprising at least a first and a second write
head located on a rotatable head drum, the first head having a gap
with a first azimuth angle and the second head having a gap with a
second azimuth angle which is different from the first azimuth
angle, the first digital information signal being meant for
enabling a replay in a reproduction apparatus at a trick play
reproduction speed which equals n1 times the recording speed, the
second digital information signal being meant for enabling a replay
in said reproduction apparatus at a trick play reproduction speed
which equals -n1 times the recording speed, where n1 is a positive
integer unequal to 0 and 1,
[0012] characterized in that the first and second trick play
signals comprise sync blocks of information of the first and second
digital information signal, respectively, and that the writing
means are adapted to write sync blocks of the first trick play
signal into first trick play segments in tracks on the record
carrier using said first write head, without using said second
write head, and to write sync blocks of the second trick play
signal into second trick play segments in tracks on the record
carrier using said second write head, without using said first
write head.
[0013] By doing so, the trick play signals for the forward and
reverse direction will be recorded in tracks with different
azimuth, so that they will never interfere with each other. This
results in a simplification of the trick play signal generation for
the two trick play directions. Further, with an equal bitrate for
both trick play speeds in the forward and reverse direction,
respectively, the overhead of the trick play information to be
recorded is equally distributed over the tracks with the one and
the other azimuth.
[0014] Further, the present invention provides a method of
recording the digital information signal and the at least two trick
play signals on a record carrier. In addition, the present
invention provides a record carrier on which the digital
information signal and the at least two trick play signals are
recorded.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a block diagram showing an embodiment of the
digital signal recording method and apparatus according to the
present invention;
[0016] FIG. 2 is an illustration showing an example of data block
format formed by the method according to the present invention;
[0017] FIG. 3 is an illustration showing an example of a
first-system track format formed by the method according to the
present invention;
[0018] FIG. 4 is an illustration showing an example of a
second-system track formed by the method according to the present
invention;
[0019] FIG. 5 is an illustration showing a track format of an
embodiment of the recording medium according to the present
invention; and
[0020] FIG. 6 is a block diagram showing an embodiment of the
digital signal reproducing apparatus according to the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] An embodiment of the present invention will be described
hereinbelow with reference to the attached drawings.
[0022] FIG. 1 is a block diagram showing a recording apparatus for
assistance in explaining the digital signal recording method and
apparatus according to the present invention. In FIG. 1, digital
signals for first-system normal reproduction (referred to as the
normal reproduction data, hereinafter) to be recorded in a first
track format are inputted through an input terminal 1.
Second-system normal reproduction data to be recorded in a second
track format are inputted through an input terminal 2a. Further,
auxiliary data (AUX) to be recorded and reproduced in the second
format separately from the second-system normal reproduction data
are inputted through an input terminal 2b. These auxiliary data
(AUX) are audio signals or other.
[0023] Here, in the present embodiment, the digital signals are
recorded on tracks formed by a helical scanning type magnetic
recording and reproducing apparatus (VTR). In this VTR, digital
signals are recorded and reproduced on and from a magnetic tape
wound obliquely around an outer circumferential side surface of a
rotary body over about an 180-degree angular range thereof.
Further, the recording and reproduction are done while the magnetic
tape is running at a constant speed, by use of two opposing rotary
heads attached to the rotary body 180 degrees away from each other
and having two different azimuth angles. Each track is constructed
by arranging a plurality of data areas of a constant data rate
(referred to as sync blocks) corresponding to the afore-mentioned
data blocks in accordance with the scanning operation of the rotary
head.
[0024] FIG. 2 shows an example of the format of a sync block. As
shown, one sync block (i.e., a data block) is a 112-byte area
formed by synthesizing, in time series manner, a two-byte
synchronizing signal (Sync) area 21 for reproducing the sync block,
a three-byte address (ID) area 22, a three-byte header storing area
23 for storing various data, a 96-byte data storing area 24, and an
eight-byte parity area 25 for correcting any error of the sync
block data.
[0025] In this embodiment, for instance, digital signals of a
transport packet (TP) transmission system of MPEG2 (Moving Picture
Expert Group 2) are recorded in the above-mentioned data storing
area 24, as the normal reproduction data or special reproduction
data. Further, a single track is formed by synthesizing a plurality
of the sync blocks in time series manner.
[0026] With respect to the track format, in the case of the first
system digital signal recording, a first track format as shown in
FIG. 3 is formed. Further, in the case of the second system digital
signal recording or the auxiliary signal recording, a second track
format as shown in FIG. 4 is formed.
[0027] The first track format as shown in FIG. 3 is composed of a
margin area 31, a pre-amble area 32, a subsidiary code area 33, a
post-amble area 34, an IBG (interblock gap) area 35, a pre-amble
area 36, a data area 37, an error correction code area 38, a
post-amble area 39, and a margin area 40. Here, the data area 37
and the error correction code area 38 constitute a major data area.
This data area 37 is composed of 306 sync blocks, in which the
first system digital signals (the normal reproduction data or the
special reproduction data) DATA1 of 306 sync blocks are recorded.
Further, the error correction code area 38 is composed of 30 sync
blocks, in which external codes (C3 codes) for correcting errors of
the first system digital signals DATA1 are recorded.
[0028] Next, the second track format shown in FIG. 4 is used for
the second system digital signals and auxiliary signals, in which
the same reference numerals have been retained for the same
composing areas shown in FIG. 3. The second track format as shown
in FIG. 4 is composed of a margin area 31, a pre-amble area 32, a
subsidiary code area 33, a post-amble area 34, an IBG area 35, a
pre-amble area 36, a first data area 41, a post-amble area 42, an
IBG area 43, a pre-amble area 44, a second data area 45, an error
correction code area 46, a post-amble area 39, and a margin area
40.
[0029] Here, the first data area 41, the post-amble area 42, the
IBG area 43, the pre-amble area 44, and the second data area 45 are
constructed by 306 sync blocks which is the same as the data area
37 shown in FIG. 3. In the 306 sync blocks, the first data area 41
is composed of 23 sync blocks, in which the auxiliary signals AUX
are recorded. Further, the post-amble area 42, the IBG area 43, and
the pre-amble area 44 are composed of two sync blocks, three sync
blocks, and one sync block, respectively, so as to construct a
rewritable edition gap area of six sync blocks as a whole.
[0030] Further, in the second data area 45, the second system
digital signals (the normal reproduction data or the special
reproduction data) DATA2 of 277 sync blocks are recorded. Further,
in the error correction code area 46, external codes (C3 codes) for
correcting errors of the second system digital signals DATA2 are
recorded. In more detail, error correction codes of 30 sync blocks
formed for the data of 306 sync blocks in total (an addition of the
277 sync block DATA2 and the 29 sync block "0" data) are recorded
in this error correction code area 46.
[0031] Returning to FIG. 1 again, when the first system normal
reproduction data are inputted through the input terminal 1, the
inputted data are written in an input buffer memory 3, and further
applied to a system detecting circuit 4 and a data rate calculating
circuit 5. The system detecting circuit 4 detects the system of the
inputted data. The data rate calculating circuit 5 calculates the
data rate of the first system normal reproduction data. Further,
when the second system normal reproduction data and the auxiliary
signals are inputted through the input terminals 2a and 2b,
respectively, the inputted data and the auxiliary signals are
written in the input buffer memory 3, and further applied to the
system detecting circuit 4. The second system normal reproduction
data is also applied to the data rate calculating circuit 5.
[0032] In accordance with the detected system, the system detecting
circuit 4 applies one-bit detection signal to a control circuit 6.
In response to the one-bit detection signal, the control circuit 6
forms and outputs various signals such as a read control signal
applied to the input buffer memory 3, a select signal applied to a
selecting circuit 9, header data, a synchronizing signal, address
data, etc. all applied to a selecting circuit 9.
[0033] The data rate detecting circuit 5 calculates the data rate
of the inputted normal reproduction data, and compares the
calculated data rate with a plurality of previously determined
reference values to detect a set data rate range to which the
inputted normal reproduction data belongs. The data rate detecting
circuit 5 then outputs a select signal according to the detected
data rate to the selecting circuit 9.
[0034] After having been stored in the input buffer memory 3, the
first or second system normal reproduction data are read in
response to the read control signal applied by the control circuit
6 and then supplied to a trick play data forming circuit 7 and the
selecting circuit 9. Further, when the auxiliary signals are stored
in the input buffer memory 3, the auxiliary signals are supplied to
a header adding circuit 10.
[0035] On the basis of the inputted normal reproduction data, the
trick play data forming circuit 7 forms of six sorts of trick
playing (special reproduction) data, and multiplexes four-byte
additional data (e.g, packet arrival time and other data) with the
formed trick playing data as an additional header, respectively.
The trick play data forming circuit 7 then outputs the six sorts of
data in parallel to write these data in six dedicated buffer
memories 8 (TP1B to TP6B), respectively.
[0036] More in detail, the trick play data forming circuit 7
decodes the inputted normal reproduction data (MPEG transport
stream), takes away some frames of the inputted data in accordance
with trick play reproduction speeds, and encodes the data. Instead
of that, the trick play data forming circuit 7 may take out packets
including independently reproducible blocks in accordance with
trick play reproduction speeds. Further, the trick play data
forming circuit 7 is not required when data of normal reproduction
data and previously formed trick play data being time-division
multiplexed with each other via input terminal 1 are distributed to
the input buffer memory 3 and buffer memories 8, respectively.
[0037] The construction of the same sorts of the special
reproduction data is the same in both the cases where the first and
second system digital signals are recorded.
[0038] The respective data stored in the six buffer memories 8
(TP1B to TP6B) are read on the basis of the read signal applied by
the control circuit 6, and then inputted to the selecting circuit
9. The selecting circuit 9 selects any of the normal reproduction
data and the six sorts of the special reproduction data TP1 to TP6
on the basis of both select signals applied by the control circuit
6 and the data rate calculating circuit 5. The selecting circuit 9
then supplies the selected data to the header adding circuit
10.
[0039] In other words, the selecting circuit 9 selects and outputs
any of the normal reproduction data and the six sorts of the
special reproduction data TP1 to TP6 in a previously determined
specific sequence. Further, when any of the six sorts of the
special reproduction digital signals are outputted, any of the
special reproduction data and the normal reproduction data are
selected and outputted according to the data rate of the normal
reproduction data detected by the data rate calculating circuit 5.
In this case, as the data rate of the normal reproduction data
increases, the normal reproduction data are selected, instead of
the special reproduction data (e.g., TP1 to TP6) of a lower
priority.
[0040] Further, when the special reproduction data TP2 to TP6 are
selected and outputted, as described later in further detail, the
selecting circuit 9 selects those data in such a way that: a
plurality of data blocks of the special reproduction data recorded
under overlapped conditions are arranged in both front and rear of
a plurality of data blocks of the special reproduction data
recorded once without being overlapped.
[0041] The normal reproduction data and the special reproduction
data TP1 to TP6 or time-series synthesized data formed of parts of
these data all outputted by the selecting circuit 9 are supplied to
the header adding circuit 10. The header adding circuit 10 adds
three-byte header data applied by the control circuit 6 to the head
of these data. The header data are stored in the header storing
area 23 shown in FIG. 2. In this embodiment, the header data
includes at least map data and a discriminate data. The map data
indicates a track pattern (e.g., as shown in FIG. 5) in which the
six-sorts of special reproduction data TP1 to TP6 are arranged and
recorded on a specific area previously determined on the tape-form
recording medium 18. The discriminate data discriminates which one
of the special reproducing data TP1 to TP6 and the normal
reproduction data are selected and recorded on the six-sorts of
special reproduction data (TP1 to TP6) recording areas,
respectively.
[0042] The 99-byte digital signals composed of the header and the
normal reproduction data or the special reproduction data both read
by the header adding circuit 10 are supplied to an external code
forming circuit 11. This external code forming circuit 11 forms 30
sync block external codes as the error correcting codes for the
sync block data recorded on one-track data area. The sync block
data are 306 sync block data stored in the data area 37 shown in
FIG. 3 in the case of the first system. Or, the sync block data are
277 sync block data stored in the data area 45 shown in FIG. 4 in
the case of the second system.
[0043] In the second system, the external code forming circuit 11
forms an external code for 306 (in total) sync block data obtained
by adding the 277 sync block input digital signals and 29 sync
block "0" data corresponding to 29 sync blocks of the data area 41,
the post-amble area 42, the IBG area 43, and the pre-amble area 44
shown in FIG. 4. The external code is stored in the error
correcting code area 38 shown in FIG. 3 in the case of the first
system digital signals. Or, the external code is stored in the
error correcting code area 46 shown in FIG. 4 in the case of the
second system digital signals.
[0044] The digital signals composed of the header, the digital data
and the external codes formed by the external code forming circuit
11 are supplied to an internal code forming circuit 13. The
internal code forming circuit 13 forms an eight-byte parity as an
internal code in unit of 99 bytes. Further, the header and the
auxiliary data (AUX) read by the header adding circuit 10 are
inputted to another external code forming circuit 12. The external
code forming circuit 12 forms 5 sync block external codes for each
18 sync blocks. The auxiliary data of 23 sync blocks are supplied
to another internal code forming circuit 14, to form an eight-byte
parity as an internal code in unit of 99 bytes.
[0045] The digital signals of data, a header, external codes, and
internal codes formed by the internal code forming circuits 13 and
14 are supplied to an adder circuit 15. The adder circuit 15 forms
sync blocks by adding the two-byte synchronizing signal as shown by
Sync and the three-byte address data as shown by ID both in FIG. 2
to the supplied digital signals. After that, the digital signals
are supplied to another selecting circuit 16 in unit of sync
blocks. When the first system normal reproduction data are inputted
through the input terminal 1, in response to the select signal
applied by the control circuit 6, the selecting circuit 16 selects
the sync blocks including the first system normal reproduction data
or the special reproduction data. These are the data inputted
through the internal code forming circuit 13 and the adder circuit
15, respectively. On the other hand, when the second system normal
reproduction data and the auxiliary data (AUX) are inputted through
the input terminals 2a and 2b, respectively, in response to the
select signal applied by the control circuit 6, the selecting
circuit 16 selects the sync blocks including the second system
normal reproduction data or the special reproduction data or the
auxiliary data (AUX). These are the data inputted through the
internal code forming circuit 13 and 14 and the adder circuit 15,
respectively.
[0046] The output signals of the selecting circuit 16 are
multiplexed with a pre-amble signal, a subsidiary code signal, a
post-amble signal, etc., to be recorded in the areas 32, 33, 34,
39, 42, 44, etc. shown in FIGS. 3 and 4. The multiplexed data are
then modulated and amplified by a signal recording circuit 17.
Further, the modulated and amplified signals are recorded on the
recording medium 18 (a magnetic tape, in this embodiment) by a
recording mechanism using a well-known rotary head (not shown). As
described above, the normal reproduction data and the special
reproduction data TP1 to TP6 can be recorded by forming the track
pattern as shown in FIG. 5. Further, the normal reproduction data
are recorded, instead of a part or all of the special reproduction
data TP1 to TP6, according to the data rate of the normal
reproduction data.
[0047] Further, in the case where the second system digital signals
are recorded, only one of the second system normal reproduction
data inputted through the input terminal 2a and the auxiliary data
(AUX) inputted through the input terminal 2b can be recorded
independently.
[0048] The track pattern of an embodiment of the recording medium
according to the present invention will be described hereinbelow
with reference to FIG. 5. FIG. 5 shows 24 pairs of tracks (i.e., 48
tracks) recorded by a first rotary head having a positive azimuth
angle and a second rotary head having a negative azimuth angle.
Further, each track shows the 336 sync blocks composed of the 306
sync block data area 37 and the 30 sync block error correcting code
area 38 both shown in FIG. 3. Or, each track shows the 336 sync
blocks composed of the data areas from the first data area 41 to
the error correcting code area 46 shown in FIG. 4.
[0049] As understood by FIG. 5, the special reproduction data TP1
to TP6 are arranged and recorded at previously determined specific
positions. The recording ranges are set to the second data area 45
of 277 sync blocks (excluding the first data area 41 of 23 sync
blocks and the editing gap of six sync blocks composed of the areas
42 to 44). Also in the case of recording the first system digital
signals, the special reproduction data TP1 to TP6 are recorded at a
part of the 277 sync block range excluding the 29 head sync blocks
from the data area 37 of 306 sync blocks shown in FIG. 3.
[0050] In this embodiment shown in FIG. 5, various data are
recorded at previously determined specific positions, respectively.
These various data are the first special reproduction data TP1 of
four-time (4.times.) speed in the forward direction, the second
special reproduction data TP2 of 12-time (12.times.) speed in the
forward direction, the third special reproduction data TP3 of
24-time (24.times.) speed in the forward direction, the fourth
special reproduction data TP4 of four-time (-4.times.) speed in the
reverse direction, the fifth special reproduction data TP5 of
12-time (-12.times.) speed in the reverse direction, and the six
special reproduction data TP4 of 24-time (-24.times.) speed in the
reverse direction.
[0051] Here, the first special reproduction data TP1 are composed
of 45 sync blocks; the second special reproduction data TP2 are
composed of 46 sync blocks; the third special reproduction data TP3
are composed of 14 sync blocks; the fourth special reproduction
data TP4 are composed of 58 sync blocks; the fifth special
reproduction data TP5 are composed of 23 sync blocks; and the six
special reproduction data TP6 are composed of 13 sync blocks,
respectively. The block lengths of these special reproduction data
are set in such a way that the data can be reproduced even if the
rotary head scanning is slightly shifted from the predetermined
pattern in the trick playing operation.
[0052] Further, in FIG. 5, the portions where the special
reproduction data TP1 to TP6 are not recorded indicate the track
portions where the normal reproduction data are recorded. In
addition, two white portions between which each special
reproduction data TP2 to TP6 is sandwiched are sync blocks where
the same data are recorded.
[0053] Table 1 lists the number of sync blocks, the recording data
rate, the reproducing data rate, etc. of the respective special
reproduction data on the track pattern shown in FIG. 5. In Table 1,
SB is an abbreviation of sync block, and the number of sync blocks
are calculated on the condition that one SB is 94 bytes on an
average.
1TABLE 1 BU- S- S- REC REP SP RST/S B(a)/ B(b)/ REC REP D-RT D-RT R
CN SCN SCN SB/TPF SB/SCN kbps kbps +4 2 45 0 90 90 507.6 2.03 +12 3
14 16 138 90 259.44 2.03 +24 9 6 4 126 90 118.44 2.03 -4 2 32 13
116 90 654.24 2.03 -12 5 13 5 115 90 216.2 2.03 -24 9 7 3 117 90
109.98 2.03 (SP R: a speed ratio; SCN: scanning; REC: recording;
REP: reproduction; and D-RT: data rate)
[0054] Further, SB(a) denotes the number of sync blocks in which
data is recorded once in the special reproduction data blocks;
SB(b) denotes the number of sync blocks in which the same data are
recorded twice in the special reproduction data blocks; and TPF
implies trick play frame; and SCN implies one revolution of a
rotary body (e.g., a rotary drum).
[0055] When all the six sorts of special reproduction data TP1 to
TP6 are recorded as shown in FIG. 5 in accordance with Table 1, the
ratio of all the special reproduction data rate to all the recorded
data rate (60.times.306 (SB/s)) is 13.5%. This is because all the
special reproduction data are recorded at a speed of 2481.25 SB per
second. In this case, the recordable data rate of the normal
reproduction data is 11.9 Mbps.
[0056] The embodiment is described under the condition that the
data rate of the normal reproduction data is changed.
[0057] And, the recorded data rate of the special reproduction data
is reduced when the data rate of the normal reproduction data
becomes higher than 11.9 Mbs. In this case, during reproduction,
the special reproduction data TP1 to TP6 are reduced beginning from
the lower priority order in sequence.
[0058] In the embodiment, the priority order of the 24-time speed
special reproduction data TP3 and TP6 is the lowest priority.
Further the priority increases in the order of the
reverse-direction four-time speed special reproduction data TP4,
the forward-direction four-time special reproduction data TP1, the
reverse-direction 12-time speed special reproduction data TP5, the
forward-direction 12-time special reproduction data TP2. Then, as
the data rate of the normal reproduction data increases beyond 11.9
Mbps, the special reproduction data recording is omitted in the
order of (1)TP3 and TP6, (2)TP4, (3)TP1, (4)TP5, (5)TP2. Further,
finally, all the special reproduction data recordings are omitted,
and only the normal reproduction data are recorded.
[0059] Table 2 lists the recorded special reproduction data, the
proportion occupied by the special reproduction data, and the data
rate of the recordable normal reproduction data.
2TABLE 2 RATIO OCCUPIED RECORDABLE NOR RECORDED SPL DATA BY SPL
DATA (%) DATA RATE (Mbps) NONE 0 13.8 TP2 1.9 13.5 TP2, TP5 3.4
13.3 TP2, TP5, TP1 7.1 12.8 TP2, TP5, TP1, TP4 11.9 12.2 TP2, TP5,
TP1, TP4, TP3, 13.5 11.9 TP6
[0060] In the above Table 2, the recordable and reproducible normal
reproduction data rate is the data rate of the first-system normal
reproduction data recorded by the first format. Therefore, the
second-system normal reproduction data recorded by the second
format becomes smaller than these listed values by about 1.31 Mbps
(=(23+6) SB/track.times.60 track/s.times.94 byte/SB.times.8
bit/byte).
[0061] In the present embodiment, in both the cases where the
first-system digital signals and the second-system digital systems
are recorded, the data rate required for the special reproduction
data TP1 to TP6 is the same as far as the same sort of the special
reproduction data are recorded. It is thus possible to use the
trick play data forming circuit 7 for forming the special
reproduction data in common for both the first and second system
digital signals. This results in the forming circuit being
simplified to that extent.
[0062] Further, in the present embodiment, in both the cases where
the first-system digital signals and the second-system digital
signals are recorded, the recording positions where the special
reproduction data TP1 to TP6 are recorded are fixedly determined as
shown in FIG. 5. It is thus possible to simplify the function
required for the circuit for arranging and recording the special
reproduction data TP1 to TP6 on the track to that extent.
[0063] Now, the construction and operation of the digital signal
reproducing apparatus for reproducing the recording medium
according to the present invention will be described hereinbelow
with reference to FIG. 6.
[0064] A recording medium 51 is the same as the recording medium 18
shown in FIG. 1, which is formed with a track pattern as shown in
FIG. 5. After having been reproduced by use of a well-known
reproducing mechanism (including the rotary head), the reproduced
digital signals are amplified and demodulated by a signal
reproducing circuit 52. And then the demodulated signals are
applied to an ID detecting circuit 53 to detect the address data
(ID). On the basis of the ID detected by the ID detecting circuit
53, the digital signals stored in the data area 37 and the error
correction code area 38 shown in FIG. 3 are supplied to an error
correcting circuit 54. Further, On the basis of the ID, the digital
signals stored in the data area 45 and the error correction code
area 46 shown in FIG. 4 are also supplied to the error correcting
circuit 54. On the other hand, the reproduced digital data (AUX)
stored in the data area 41 shown in FIG. 4 are supplied to another
error correcting circuit 55.
[0065] The reproduced digital signals error-corrected by the error
correcting circuit 54 are supplied to a control circuit 56 and
further to a data distributing circuit 57. Further, the reproduced
digital signals error-corrected by the error correcting circuit 55
are supplied to an AUX buffer memory 58.
[0066] The control circuit 56 analyzes the header of the reproduced
digital signals and outputs a control signal to the data
distributing circuit 57. Further, the control circuit 56 generates
write control signals WTP1 to WTP6, WN and WA applied to buffer
memories 59-1 to 59-6, a normal buffer memory 60 and an AUX buffer
memory 58, respectively. In addition, the control circuit 56
analyzes the four-byte additional data (additional header) of the
reproduced digital signals to detect the data arrival time, and
generates read-out control signals RTP1 to RTP6 and RN and RA, so
that all the data can be read at the same timing.
[0067] On the basis of the control signals, when the inputted
reproduced digital signals are of the special reproduction data TP1
to TP6, the data distributing circuit 57 distributes the reproduced
digital signals to each of the dedicated buffer memory 59-1 to
59-6. Further, when the inputted reproduced digital signals are of
the normal reproduction data, the data distributing circuit 57
supplies the reproduced digital signals to the normal buffer memory
60. In the case of the special reproduction data TP2 to TP6, only
one of the two places (the white portions in FIG. 5) where the same
data blocks of the special reproduction data are recorded is
selected and outputted. Therefore, even if the head scanning is
slightly shifted away from the predetermined pattern, it is
possible to reproduce the special reproduction data under excellent
conditions.
[0068] The special reproduction data TP1 to TP6 stored in the
buffer memories 59-1 to 59-6, respectively, and the normal
reproduction data stored in the buffer memory 60 are read on the
basis of read control signals RTP1 to RTP6 and RN. And the read
signals are inputted to a selecting circuit 61. The selecting
circuit 61 selects one sort of data designated by the control
circuit 56 and outputs the selected data as the reproduction data.
On the other hand, when the auxiliary data (AUX) are reproduced,
the control circuit 56 supplies a read control signal RA to the AUX
buffer memory 58 that outputs the reproduced auxiliary data.
[0069] Further, the present invention is not limited only to the
above-mentioned description. For instance, the present embodiment
has been explained by taking the case where digital signals are
recorded and reproduced in accordance with any one of the
two-system formats. However, the present invention can be applied
to the case of three or more system formats by recording the
special reproduction data at a part of the area common for all the
systems.
[0070] Further, in the above-mentioned embodiment, any one of the
first system and the second system is decided automatically by the
system detecting circuit 4. Without being limited only thereto, the
system can be of course decided manually. Further, in the
above-mentioned embodiment, the special reproduction data are
formed on the basis of the normal reproduction data. It is also
possible to form and input the special reproduction data separately
from the normal reproduction data.
[0071] As described above, in the digital signal recording method
and apparatus according to the present invention, the same area for
recording the special reproduction digital signals are used in
common for both the first and second format recordings. It is thus
possible to use the circuit for arranging and recording the special
reproduction digital signals on the tracks in common for each
format recording. This results in the simplified circuit
construction.
[0072] Further, in the digital signal recording method and
apparatus according to the present invention, the special
reproduction digital signals are recorded in the same construction
in both the first and second format recordings. Further, the data
rate of the special reproduction digital signals is equalized in
both the first and second format recordings. It is thus possible to
use the circuit for forming the special digital signals in common
for each format recording. This results in the simplified circuit
construction.
[0073] Further, in the digital signal recording method and
apparatus according to the present invention, any of the special
reproduction digital signals and the normal reproduction digital
signals are selected and recorded at the recording area for the
special reproduction digital signals, according to the data rate of
the normal reproduction digital signals. It is thus possible to
eliminate the switching of the circuits (for addressing) for
arranging the special reproduction digital signals. This results in
the circuit function being reduced markedly.
[0074] Further, in the recording medium according to the present
invention, the special reproduction digital signals (instead of the
normal reproduction digital signals) are recorded in a specific
area previously determined in the digital signal recording area
used in common for both the first and second formats on the
respective tracks. It is thus possible to reproduce the special
reproduction digital signals from the same area in any format
reproduction by the reproducing apparatus.
* * * * *