JP2712213B2 - Information signal recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]   The present invention relates to an information signal recording device, particularly a helical scanning device.
The present invention relates to a device for recording an information signal of a channel type. [Conventional technology]   Track format of 8mm VTR magnetic tape is
It is determined as shown in FIG.   That is, in FIG.
The magnetic tracks 2 are 180 ° apart from each other.
By two rotating magnetic heads with a space, tape 1
Oblique to the rotation angle of the rotary head at 221 °
Is formed or scanned to a length corresponding to. And magnetic
Equivalent to 36 ° rotation angle of rotating head from the tip of rack 2
Section 2S to be used for audio signals, and the remaining 185 ° rotation angle
The corresponding section 2V is used for video signals.   Then, the audio track 2S is divided into sections 21 with the distribution shown in the figure.
2525, and section 21 is the scanning start section of the rotary head
(Head entry section), section 22 is clock run-in recording
The preamble section to be reproduced, section 23, is a PCM signal
PCM audio data section for recording and playback of PCM audio signals
Interval 24 is after-recording (hereinafter abbreviated as post-recording)
Postamble section for back margin at the time
And section 25 is a guard section for tracks 2S and 2V.
ing.   In this case, the PCM audio data in section 23 is one file.
Stereo audio signal for the threshold period is compressed with time axis and PCM
It is signalized and includes error correction codes and ID codes.
The signal has And the signal of section 22-24
Is 2.9 MHz when the value is “0” and 5. when it is “1”.
Converted to 8MHz bi-phase mark signal and recorded
Have been.   In addition, the video track 2V is 180
Section 28 corresponding to a rotation angle of 5 ° and the remaining rotation angle of 5 °
It is divided into the corresponding section 29. Section 28 is a video signal section
In this section 28, the FM modulated by the luminance signal
Signal, low-frequency converted carrier color signal, and monaural audio signal
Signal and the frequency of the pilot signal
One field of the number multiplexed signal is recorded and reproduced. Also,
Section 29 is the scanning end section of the rotating head (head separation section).
It is.   According to such a format, the audio data section 23
Since the ID code is recorded at the same time as the audio signal,
Various data as ID code, for example, recording date,
The position, program number, etc. can be recorded.
It is very convenient for editing or editing.   By the way, the ID code is recorded in the voice data section 23.
When interleaving together with PCM audio data
It is recorded in the interval 23 and recorded. Therefore, correct the ID code.
To play properly, the rotating head stretches section 23 for a considerable length
Need to be scanned correctly.   However, at the time of search reproduction, the magnetic tape 1
For example, since it runs at 30 times the speed, the rotating head
Will be scanned diagonally across the
During playback, make sure the ID code is correct for a considerable period of time.
Sometimes playback is not possible.   Therefore, the ID is added to the postamble section 24 of the audio track 25.
Consider recording and reproducing index signals such as codes.
Has been obtained.   That is, this section 24 corresponds to 2.06 ° of the rotating head.
It is the length, but if you convert this to the length of time, the rotation angle
180 ° is equal to 262.5H (1H is one horizontal period).
The length of time between 24 Becomes For example, as shown in FIGS. 10A and 10B, the section 24 is the first half.
Is divided into the 1.5H section 241 of the
You. Then, as shown in FIG.
All “1” postamble section for CM audio data
The section 242 is an index section.
In this section 242, all “1”
Lock run signal S_CLIs recorded, and the index is recorded in the remaining 1H section.
The audio signal CDIX is recorded.   Then, the index signal CDIX is as shown in FIG.
Is equally divided into blocks BLK1 to BLK6 and end marks,
Further, as shown in FIG.
Bit header, 8-bit ID codes ID0 to ID4, and
And an 8-bit CRC code for them.   In this case, blocks BLK1 to BLK6 are PCM audio data sections.
Mode 1 to which ID codes ID0 to ID4 recorded in interval 23 belong
Corresponds to mode 6, ID codes ID0 to ID4 are recorded in section 23
ID code ID0 to ID4
Cut at each cut of absolute position and recorded contents on
Number, date, hour, minute, second, etc.
You.   Also, the index signal in index section 242 is
No. CDIX is “0” like the signal in the audio track 2S.
Sometimes 2.9MHz, when set to "1", 5.8MHz
It is recorded after being converted into an is mark signal.   Recording format of such index signal CDIX
According to the above, at the time of variable-speed reproduction, the rotating head tilts the track 2
Index section 242 is 1.5 horizontal
Since the section is short, for example, even when searching for
The rotating head is almost correctly
King and operate, index signal CDIX
(ID code) can be reliably reproduced.   The meaning of the ID code differs depending on modes 1 to 6.
Recorded in section 23 together with PCM audio data.
If you use an ID code, play 6 tracks
And requires 6 field periods,
According to the above format, one index section
242 is indexed by ID code of all modes 1-6
Since it is recorded as signal CDIX, one horizontal section 242
All you have to do is play the section and get the required ID code immediately.
Can be   After recording the video and audio signals,
Only the signal CDIX can be recorded independently.
Attach chapter signals etc. to the collected magnetic tape 1
Can be [Problems to be solved by the invention]   Index section recorded in the above format
When dubbing during interval 242, PCM audio data section 23 is usually
Decodes the address recorded in the index section
242 is generated and overwriting is performed in that section.
Was. Therefore, if the PCM audio data section 23 contains a PCM audio
If no data is recorded, index section 24
2 cannot be generated and the index signal CDIX
Recording could not be performed. For this reason, in the past,
Prior to the dubbing of Decks section 242, the user
Determines the presence or absence of audio data and sets the recording / playback device to PCM audio.
Mode with data or mode without PCM audio
I had to set it somewhere.   When the mode with PCM audio data is selected, the 11th
As shown in the figure, the PCM audio data
The index section 242 is defined based on the dress
Dex signal CDIX is recorded and no PCM audio data is recorded.
When the new mode is selected, as shown in Fig. 12,
Newly set index section 242 for each field
Continuously silent signal, so-called PCM carrier C_PCMAnd Inn
The recording of the dex signal CDIX is performed.   However, if you select the mode with PCM audio data,
The PCM audio data is shown in Figure 11
When recorded in a discontinuous state, the index
Section 242 is also formed correspondingly, so PCM audio data
The index section 242 cannot be specified in the part without data.
There was a problem. In addition, in FIG.
Area where 2V is recorded, 4 is the index section 242
Area 5 is audio data section 23 and preamble section 22
Etc., and the dots in the figure indicate PCM audio data.
Data and the portion of the index signal CDIX not recorded
Are shown.   When the mode without PCM audio data is selected
As shown by the hatched lines in FIG. 12,
PCM carrier C_PCMAnd the index signal CDIX is recorded
You. Therefore, the recorded old PCM audio data 2 indicated by the solid line
Three₀Even if there is a PCM carrier C mentioned above_PCMAnd index
The problem is that they are erased by the source signal CDIX.
Therefore, improvement of these problems has been desired.   Therefore, it is an object of the present invention whether or not there is a PCM signal.
The index section is defined continuously without
Signal is recorded within the
Recording of information signals without erasing PCM signals
It is to provide a device. [Means for solving the problem]   The present invention provides a magnetic head with respect to the rotating surface of a rotating magnetic head.
Tape runs at a constant speed diagonally over a range of corners
And an information signal is supplied to the rotating magnetic head for a predetermined period.
And sequentially recorded on the magnetic tape as diagonal magnetic tracks
Helical scan type information signal recording device
And   A PCM signal is recorded for each field of the magnetic track.
Means for determining whether or not   Define the index interval from a specific signal in the PCM signal
A first timing generator,   Rotation generated in synchronization with the rotation phase of the rotating magnetic head
From the detection signal to the index section and the index section
Second timing element defining the carrier signal section to be executed
Generator and   When the PCM signal is recorded based on the determination,
Based on the output of the first timing generator,
The signal is recorded in the dex section, and the PCM signal is recorded.
If not, the output of the second timing generator
Record carrier signal in carrier signal section based on
And means for recording signals in the index section.
An information signal recording device characterized by the following. [Action]   A PCM signal is recorded for each field of the magnetic track.
It is determined whether or not it has been performed.   The PCM signal is recorded from the first timing generator.
Index section only when it is determined that it is recorded
Is output. This signal is within the PCM signal
Decodes the address of
Formed.   On the other hand, from the second timing generator, the PC
Regardless of the result of M signal presence / absence determination,
A signal defining the interval is output. This signal is
The shape is based on the rotation detection signal obtained by the rotation of the head.
Is done.   The CRCC in the PCM signal is checked and there is no error.
If it is determined, the output of the first timing generator
Force is selected. This first timing generator
Signal is output, the PCM signal is
The index section is defined from the absolute position on the tape,
Required signal recording is performed in this index section.   Also, as a result of the CRCC check, it was determined that there was an error
In this case, the output of the second timing generator is
Selected. From this second timing generator.
Indexed as “No PCM signal” by the input signal
The new section and its associated section are newly set and
For the dex section and the section set accompanying it
The required signal recording is performed.   Note that when no PCM signal is recorded,
Section setting is performed in the same manner as when the
And signal recording is performed. 〔Example〕   Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
I will tell. This description is made in the following order. (A) Outline of VTR configuration and general records in VTR
Circuit operation during playback (B) Clock run signal and IN when PCM signal is present
Recording and playback of dex signals (C) Carrier signal and clock signal when there is no PCM signal
Recording / playback of audio signals and index signals (A) Outline of VTR configuration and general records in VTR
Circuit operation during playback   FIG. 1 shows a VTR as an information signal recording device.
In FIG. 1, reference numeral 55 denotes a system for explaining the operation of this VTR.
System controller (hereinafter abbreviated as syscon).
Monitors such as the recording switch and playback switch connected to this
When the mode switch 56 is operated, the VTR is
Operation mode corresponding to the operated mode switch 56
Is controlled.   34A and 34B are rotating magnetic heads (hereinafter simply referred to as heads).
The heads 34A and 34B are 180 ° apart from each other.
A frame is provided by a motor 62 through a rotating shaft 61.
Rotated at the wave number,
The air tape 1 is obliquely constant over an angular range of approximately 221 °.
They are running at speed. And in this case, the illustration is
However, the rotation phases of the heads 34A and 34B do not
During playback so that it is synchronized with the video signal recorded
Servo controlled to correctly scan the air track 2
You. Therefore, as shown in FIG.
In the field period Ta, the head 34A is set to 1/5 of the beginning of the period Ta.
Scan section 2S during the field period, and then
The second section 28 is scanned. Also every other field period
During the period Tb, the head 34B receives the 1 / 5th of the first period of the period Tb.
Scan the section 2S during the magnetic field 2
The section 28 is scanned.   During general recording, the color video signal S_cAnd monaural sound
The voice signal Sm is supplied to the recording processing circuit 31 and the FM luminance signal
, The low-frequency converted carrier color signal, the FM audio signal,
The frequency multiplexed signal Sf with the lot signal is shown in FIG.
The signal Sf is continuously extracted as shown in FIG.
Supplied to   In addition, a pulse generating means 63 is provided on
The rotation phases of the heads 34A and 34B are shown for each rotation of the heads 34A and 34B.
The pulse Pg of the frame period is extracted. This pulse Pg
Is supplied to the signal forming circuit 65 through the shaping amplifier 64 and
As shown in FIG. C, the rectangular wave signal S is inverted every period Ta and Tb.
w is taken out and this signal Sw
It is supplied as a control signal. The switch circuit 32 has the period Ta and Tb
Thus, the state is switched to the state opposite to the state shown in FIG. Follow
As a result, as shown in FIG.
f is extracted alternately for each of the periods Ta and Tb. This signal Sf, S
f passes through the recording amplifiers 33A and 33B and further switches 67
A is supplied to the heads 34A and 34B through the recording side contact R of A and 67B.
You. Therefore, the signals Sf and Sf are recorded on the tape 1 every period Ta and Tb.
These are sequentially recorded as video signal sections 28, 28.   Then, the stereo audio signals L and R are supplied to the recording processing circuit 41.
And the signal Sw is supplied to the formation circuit 66 to
As shown in FIG.
A and 34B define preamble section 22 and PCM voice data section 23
A pulse Ps that goes to “H” level is formed during scanning.
It is. This pulse Ps is supplied to the recording processing circuit 41,
As shown in F, the signals L and R for one field period are Ps =
During the “H” period, the time axis is compressed and converted into a PCM signal.
After the preamble signal of section 22 is added,
The smark is modulated and extracted as a signal Ss.   This signal Ss is output during the field period Ta (the OR circuit 42).
→ Switch circuit 32 → Recording amplifier 33B → Switch circuit 67B
Through the signal line of the contact R) to the head 34B,
During the period Tb, [OR circuit 42 → switch circuit 32 → recording
33A → Through the signal line of the contact R of the switch circuit 67A
] Is supplied to the head 34A. Therefore, the magnetic track 2
Before recording the signal Sf for the video signal section 28,
In sections 22 and 23, the signal Ss (preamble signal and PCM audio
Data] is recorded.   Also, the index signal CDIX controls the
While being supplied from the controller 52 to the recording processing circuit 51,
In the generating circuit 66, the rising point (or the signal
The pulse Pi is formed with reference to the Sw change point). this
The pulse Pi is supplied to the recording processing circuit 51, as shown in FIG.
As shown, bi-phase mark modulation was performed during Pi = “H”.
Extracted as signal Si.   This signal Si is output during the field period Ta (OR circuit 42).
→ Switch circuit 32 → Recording amplifier 33B → Switch circuit 67B
Through the signal line of the contact R) to the head 34B,
In the field period Tb, (OR circuit 42 → switch circuit 32
→ Recording amplifier 33A → Signal line of contact R of switch circuit 67A
Through the head) to the head 34A. Therefore, the magnetic
In the rack 2, the signal Ss is recorded in the PCM audio data section 23.
Subsequently, the signal Si is recorded.   On the other hand, at the time of reproduction, the magnetic tracks are provided by the heads 34A and 34B.
Signals Ss, Si and Sf from step 2 are as shown in FIG.
And the reproduced signals Ss, Si and Sf are alternately reproduced.
Through the reproduction side contact P of the switch circuits 67A and 67B,
It is supplied to the switch circuit 36 through the raw amplifiers 35A and 35B.
You. The signal Sw is sent to the switch circuit 36 as its control signal.
Supplied, and the signal Sf is continuously taken from the switch circuit 36.
Will be issued. And the signals Ss, Si are
Taken out. The signal Sf from the switch circuit 36 is played back.
The original color video signal Sc and the monaural signal supplied to the circuit 37
The audio signal Sm is extracted.   Also, the signals Ss and Si from the switch circuit 36 are used for reproduction processing.
And the pulse Ps is supplied to the reproduction processing circuit 43.
It is supplied as a window signal and is
Leo audio signals L and R are extracted.   Then, the signals Ss and Si from the switch circuit 36 are subjected to the reproduction processing.
The index signal CDIX is supplied from the signal Si to the circuit
The index signal CDIX is extracted from the controller
Supplied to 52 and used for cueing.   FIG. 3 shows an example of the recording processing circuit 51 and the reproduction processing circuit 53.
This means that the part indicated by the dashed line is integrated into one chip.
ing.   That is, in the figure, 45 indicates a clock forming circuit,
The clock formed by this is used as the recording processing circuit 41,
While being supplied to the processing circuit 43, the recording processing circuit 51
It is supplied to the processing circuit 53. 90 is a control signal forming circuit
This control signal forming circuit 90 is based on the pulse Pi.
Various control signals are formed at predetermined timings
These control signals and the clock of the clock forming circuit 45
Is supplied to each circuit.   At the time of recording, the heads 34A and 34B
Index from controller 52 during non-scanning period
The signal CDIX is output, and this index signal CDIX is
Is supplied to the buffer RAM 71 through the switch circuit 72.
In both cases, the address signal is switched from the address forming circuit 73 to the switch.
It is supplied to the RAM 71 through the circuit 74 and is recorded in the RAM 71
The power index signal CDIX is stored.   Then, when the pulse Pi becomes “H” level, the recording signal
During normal recording, the clock run signal S
_CLIs output.
In the mode, the carrier signal S_CAAnd clock run signal S_CL
Is output. This carrier signal S_CA, Clock run signal
No.S_CLAre supplied to the encoder 85 and the bi-phase
The signal Si is modulated and encoded into the signal Si.
Output to the switch circuit 32.   Next, the heads 34A and 34B pass through the clock run signal section 101.
Immediately before passing, the address forming circuit 73 switches to the switch circuit 74.
Address signal is supplied to RAM 71 through
The signal CDIX is read. And this index signal
No. CDIX is supplied to the register 83 through the switch circuit 72.
From a parallel signal to a serial signal.
The converted index signal CDIX is sent to the CRCC forming circuit 84.
It is supplied and a CRC code is added. Attaching this CRC code
The index signal CDIX added is the clock run signal described above.
No.S_CLAnd then supplied to the encoder 85
Is modulated and converted into a signal Si.
Output to the switch circuit 32.   Therefore, the beginning of the magnetic track 2 and the video signal section 28
, The index section 100 is set accurately.   On the other hand, during reproduction, the signal Ss from the switch circuit 36 is decoded.
The index signal CDIX is supplied to the coder 86 and decoded.
The index signal CDIX is output to the CRCC check circuit 87.
Of the index signal CDIX by the CRC code
An error check is performed. In from check circuit 87
The dex signal CDIX is supplied to the register 88 and the serial signal
Signal into a parallel signal, and this parallelized
The index signal CDIX is supplied to the RAM 71 through the switch circuit 72.
Is written to. At this time, the address forming circuit 73
Address signal to the RAM 71 through the switch circuit 74
Is supplied.   Then, the writing of the index signal CDIX ends.
And RAM 71 from the controller 52 through the switch circuit 74.
Address signal is supplied to the
And the read index signal CDIX is scanned.
It is taken into the controller 52 through the switch circuit 72, and
After that, processing corresponding to the index signal, for example,
And so on.   The above is the outline of the VTR configuration and general recording / playback.
Circuit operation. (B) Clock run signal and IN when PCM signal is present
About recording of index signals   In the recording / reproducing apparatus shown in FIG.
As shown in the figure, approximately half of the audio track 2S of the frame f is
A PCM data determination area 102 is provided. Rotating magnetic head
For example, 34A scans this PCM data determination area 102.
PCM audio data of the signal Ss
PCM deco in the reproduction processing circuit 43 shown in FIG.
And reproduces it. 104 is the index signal
This is the recording preparation area.   In the configuration of FIG. 5, the PCM decoder 103 outputs PCM audio.
Separate addresses in data and use CRC code
Check for errors. According to the above check
If there is no error, it is determined that "PCM signal exists"
The address is output to the address latch 105 of the forming circuit 66.
And a set signal indicating “PCM signal is present”
Output to the selector controller 106 composed of switches
Is done. Therefore, the selector from the selector controller 106
The controller control signal SC becomes “H”.   From the address latch 105, the aforementioned address is parallelized.
Is supplied to the timing generator 107 and the selector
The “H” selector control signal SC from the controller 106 is
To the collector 108. The selector 108 outputs an “H” level signal.
Based on the selector control signal SC, the timing generator
The output signal of the data 107 is selected and output.   In the timing generator 107, the supplied address
Load a predetermined value corresponding to the
The count value reaches a predetermined value.
In the step, the pulse Pi shown in FIG.
And outputs it to the selector 108. This pulse Pi is output to selector 1
After 08, it is output to the recording processing circuit 51.   From the recording processing circuit 51, as shown in FIG.
During the period of 2.25H when the applied pulse Pi is at the “H” level, the signal S
i (clock run signal S_CL+ Index signal CDIX]
Is forced. The pulse Pi is first supplied to the control signal forming circuit 90
Is done.   In the control signal forming circuit 90, while the pulse Pi is at the “H” level
[2.25H], as shown in FIG. 6C and FIG.
Generates control signals that define the timing of recording signal output
I do.   As shown in FIG. 6C, the period when the control signal S10 is "H"
Then, from the recording signal forming circuit 81, over 0.75H,
"1" clock run signal S_CLIs output, and then
6 As shown in FIG. D, during the “H” period of the control signal S11,
From the recording signal forming circuit 81, the clock run signal S of 0.5H_CL
Is output, followed by the 1H index signal CDIX.
Is output. These clock run signals S_CLAnd index
The signal Si is formed by the mix signal CDIX.   The signal Si output from the recording processing circuit 51 (clock run
Signal S_CLAnd the index signal CDIX]
In the interval Ta, a switch is applied from the OR circuit 42 through the switch circuit 32.
Head 34B through a signal line reaching the contact R of the switch circuit 67B.
During the field period Tb.
The signal reaching the contact R of the switch circuit 67A via the switch circuit 32
The signal is supplied to the head 34A through the signal line.   When the signal Si is output, as shown in FIG.
In the latter half of postamble section 111 [0.75H] and index
Clock run signal S at the front [0.5H] of_CLBut
Recorded over a total of 1.25H. Followed by India
Signal CDIX is recorded over 1H.
Then, when the pulse Pi falls, the timing generator
Selector 110 by the reset signal output from the
The selector control signal SC from the controller 106 is set at the “L” level.
It becomes. Therefore, the selector 108
The state is such that the output signal of the generator 110 is selected.   Thus, when it is determined that there is PCM audio data
Is based on the address in the PCM audio data.
Clock run signal section 101, index
Index section 100, etc.
It can record. Therefore, the recorded old PCM sound
Voice data 23₀Even if there is, it will be erased by after-recording
Nothing.   FIG. 7 shows the PCM block 112. This PCM block
Lock 112 consists of sink 113, address 114, data 115, and CRC
It is composed of each part of the
The PCM audio data section 23 is configured from the above. (C) Carrier signal and clock signal when there is no PCM signal
Recording of signal and index signal   The rotating magnetic head, for example, 34A has a PCM data discrimination area
Capture PCM audio data from signal Ss while scanning 102
The reproduction processing circuit 43 shown in FIG.
To the PCM decoder 103 inside.   In the configuration of FIG. 5, the PCM decoder 103 outputs PCM audio.
Separate addresses in data and use CRC code
Check for errors.   If an error is detected by checking the CRC code,
In this case, it is determined that there is no PCM signal. At this time, in FIG.
A signal formed from the pulse Pg in the signal forming circuit 65 shown
Sw is supplied to the timing generator 110. In addition, this
In this case, no address is output from the PCM decoder 103.
No.   In the timing generator 110, the signal Sw is supplied.
Count operation starts from the point when
"No PCM signal" when the specified value is reached
Is output to the selector controller 106
I do. From the selector controller 106, the “L” level
The selector control signal SC is supplied to the selector 108. Sele
The selector 108 receives the “L” level selector control signal SC and
And select the output signal of the timing generator 110.
State. In addition, the timing generator 110
8B together with the output of the reset signal described above.
The pulse Pi is output to the selector 108 over 6H. this
The pulse Pi is output to the recording processing circuit 51 via the selector 108
Is done.   In the recording processing circuit 51, the input pulse Pi is set to the “H” level.
Signal Si (carrier signal S_CA、 Clock
Clan signal S_CL, Index signal CDIX] is output
You.   This pulse Pi is first supplied to the control signal forming circuit 90.
You.   In the control signal forming circuit 90, while the pulse Pi is at the “H” level
[6H], control to define timing of various recording signal output
The signals are generated sequentially. As shown in FIG.
During the 3H period when S12 is “H”, the recording signal forming circuit 81
Signal "10" carrier signal S_CAIs output. Then the eighth
As shown in FIG. D, when the control signal S13 is "H" for 1.5H,
All “1” clock run signal S_CLIs output. Further
As shown in FIG. 8E, when the control signal S14 is "H" for 1.5H.
During this time, a 0.5H clock run signal is
No.S_CLIs output, followed by the 1H index signal C
DIX is output. These carrier signals S_CA,clock
Run signal S_CLSignal Si by index signal CDIX
It is formed.   The signal Si output from the recording processing circuit 51 (carrier signal
S_CA, Clock run signal S_CLAnd index signal CDIX)
During the field period Ta, the switch turns from the OR circuit 42.
A signal line that reaches the contact R of the switch circuit 67B via the path 32
Is supplied to the head 34B through the field period Tb.
Is the switch circuit from the OR circuit 42 through the switch circuit 32
Supplied to head 34A through signal line to 67A contact R
Is done.   As a result, as shown in FIG.
From the beginning 111a of section 111 to the preamble section 22 side
Carrier signal S_CAIs recorded over 3H,
Bull section 111 [1.5H] and front of index section 100
Clock run signal S at [0.5H]_CLRecorded over 2h
Followed by the index signal CDIX over 1H
Will be recorded.   Therefore, during the period of 3H, the carrier signal S_CAIs recorded and
Clock run signal S during the 2H period_CLHas been recorded
For the reproduced data of the clock formed by the PLL,
Can significantly improve and improve the tracking
Phase can be more accurately synchronized.   When the pulse Pi falls, the timing generator 11
From 0, a reset signal is applied to the selector controller 106 again.
Yes, the selector controller 106 makes the selector 108
The “L” level selector control signal SC is supplied and the selector
108 selects the output signal of the timing generator 110
Maintain state.   Thus, when it is determined that there is no PCM audio data
However, carrier signal section 117, clock
Specify the clan signal section 101, index section 100, etc.
Index signal CDIX can be recorded.   By the way, if no PCM audio data is recorded,
Circuit operation when the PCM audio data
Is the same as the circuit operation when "
Is omitted. 〔The invention's effect〕   According to the present invention, regardless of the presence or absence of a PCM signal,
A dex section can be defined, and
Can record index signals and still record
PCM signal is not erased.
is there.   In addition, as in the past, the user is required to record PCM signals.
It is not necessary to determine the mode and select the mode.
PCM signal is not recorded, of course if recorded
Even in this case, the index interval can be automatically defined,
There is also an effect that operability is further improved.   According to the present invention, the PCM signal is recorded.
If not, the carrier signal is recorded in the 3H section.
Further, in the embodiment, the clock run signal is generated during the period of 2H.
Because it is recorded, the clock generated by the PLL
The ability to follow playback data can be significantly improved and improved.
Synchronize the phase of lock and playback data more accurately
Can prevent data reading errors,
There is also the effect that seed data can be read accurately.
You. Also, the index signal can be recorded at an appropriate position.
Therefore, operations such as cueing and editing can be easily performed,
Another advantage is that the recorded video signal can be fully utilized.
You.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of an entire circuit showing an embodiment of the present invention, FIG. 2 is a timing chart of the circuit shown in FIG. 1, and FIG. FIG. 4 is a block diagram of a partial circuit showing an example of a recording and reproduction processing circuit, FIG. 4 is a schematic diagram showing a configuration of a frame formed on a magnetic tape, and FIG. 5 is a configuration of a forming circuit shown in FIG. FIG. 6 is a schematic diagram used to explain the definition of the index section,
FIG. 7 is a schematic diagram showing the configuration of a PCM block, FIG. 8 is a schematic diagram used to explain the definition of an index section, FIG. 9 is a schematic diagram showing a conventional track format, FIG.
FIG. 9 is a partially enlarged explanatory view of the recording format showing the structure of the postamble section in FIG. 9, and FIGS. 11 and 12 are schematic diagrams used to explain the definition of the conventional index section. Description of main reference numerals in the drawings 1: magnetic tape, 2: magnetic track, 242, 100: index section, 34A, 34B: rotating magnetic head, 107, 110: timing generator, Ta, Tb: field period, Sw: rectangular wave signal, P
s, Pi: pulse, Ss, Si, SiA, SiA 1, SiA 2: signal.

Claims (1)

(57) [Claims] A magnetic tape runs obliquely at a constant speed over a predetermined angular range with respect to a rotating peripheral surface of the rotary magnetic head, and an information signal is supplied to the rotary magnetic head for a predetermined period, and the magnetic tape is inclined on the magnetic tape. Means for determining whether a PCM signal is recorded for each field of the magnetic track, and a specific signal in the PCM signal. A first timing generator for defining an index section, and a second timing generator for defining an index section and a carrier signal section preceding the index section from a rotation detection signal generated in synchronization with the rotation phase of the rotary magnetic head. When the PCM signal is recorded based on the above determination, the first timing generator The signal is recorded in the index section based on the output of the data, and when the PCM signal is not recorded, the carrier signal is recorded in the carrier signal section based on the output of the second timing generator. Means for recording a signal in an index section.