JP3038709B2 - Information signal recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an information signal recording device, in particular, a helical scanning device.
The present invention relates to a device for recording an information signal of a channel type. [Prior Art] Track Format of Magnetic Tape of 8mm Video
Is defined 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
Angle of rotation and 221 ° rotation angle of the rotary head
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 rotation angle of 185 °
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 the PCM audio signal
PCM audio data section to be recorded and played back, section 24 is after
For recording (hereinafter abbreviated as "recording")
Postamble section for back margin, section 25
This is a guard section for the racks 2S and 2V. 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 the rotation angle of ゜ and the remaining rotation angle of 5 °
It is divided into the corresponding section 29. Section 28 is a video signal section
The FM signal modulated by the luminance signal and the low-frequency conversion
Modulated by the carrier color signal and the monaural audio signal
Of the frequency multiplexed signal of the FM signal and the pilot signal
The field is recorded and played back. Section 29 is a rotating head.
This is a scanning end section (head separation section). 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, absolute
Record position, program number, etc.
Or it is very convenient for 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 2S.
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
Is equal to 262.5H (1H is one horizontal period)
The length of time between 24 Becomes Therefore, for example, as shown in FIGS.
It is divided into a half 1.5H section 241 and the remaining half 1.5H section 242.
It is. Then, as shown in FIGS.
"1" postamble for PCM audio data
Section 242 is an index section.
You. This index section 242 is a section 0.5H from the tip
All “1” clock run signal S _CL Is recorded and the remaining 1
The index signal CDIX is recorded in the section H. And the index signal CDIX, which is
As shown in FIG. D, the blocks BLK1 to BLK6 and the endomer
And is further divided into blocks as shown in FIG.
BLK1 to BLK6 each have a 3-bit header and an 8-bit ID
Codes ID0 to ID4 and an 8-bit CRC code for them
And divided into 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] In the recording formats shown in FIGS. 7 and 8,
PCM audio signal and clock run signal S _CL And index
The signal CDIX and the video signal are recorded on the same magnetic track 2
It had been. This can be added to the PCM recording system of the recording device.
Recording / playback function of index signal CDIX was added
It was made possible for By the way, recording PCM audio signals
Camera-integrated VTR, so-called camcorder [CAM Code
r), not only PCM audio signals but also clock
Signal S _CL , Index signal CDIX etc. cannot be recorded.
Only image signals and frequency-multiplexed audio signals can be recorded
And it was. However, even with the above-mentioned camcorder,
Clan signal S _CL And the recording area of the index signal CDIX
Timing to specify timing (generate recording pulse)
According to the clock generator, the clock run signal S _CL as well as
Recording of the index signal CDIX becomes possible. However, in this case, the magnetic tape recorded by the camcorder
Group 1 has a timing generator afterwards
Clock run signal S using VCR _CL And index
Switch between VCRs to record
If there is a misalignment of the
Black run signal S _CL And the recorded index signal CDIX
Will also be shifted. For example, the reference
Switching position with respect to the switching position SWP
VCR A where the SWP1 is shifted by -1.5H and +
Using VCR B shifted by 1.5H,
Is performed, the new / old
Two clock run signals S _CL And index signal CDIX
Was sometimes recorded. That is, as shown in FIG.
The video signal section 28 on the magnetic track 2
Based on what is recorded from the switching position SWP
The clock run signal S _CL1 Passing
And index signal CDIX ₁ Is recorded as shown in FIG. 9B.
And signal S for 3H in section 100 _CL1 And CDIX ₁ Is -1.
Recorded in a state shifted from the 5H standard. The above VCR is applied to the magnetic tape 1 shown in FIG. 9B.
B, when dubbing is performed, as shown in FIG.
Then, in section 101, the clock run signal S _CL2 And index
Signal CDIX _Two [New data] is recorded. This is
The recording section 100 of the old data by Deodeck A
-1.5H shift (switching position SWP → S
WP ₁ But the recording area of new data by VCR B
Between the reference 101 and the reference is +1.5.
State SWP → SWP _Two ], The deviation of the magnetic track 2
The total amount will be 3H. Therefore, the same as the end of section 100
Occasionally, as shown in FIG.
Becomes “H”, and new data is within the 3H
Will be recorded, which causes the above-mentioned problem
Things. On the other hand, the head (not shown) that reads the signal
A system that reads the output signal preferentially, so-called look-ahead
Only priority. Therefore, as shown in FIG. 9C, 1
Clock run signal S _CL1 , S _CL2 as well as
Index signal CDIX ₁ , CDIX _Two Are recorded respectively
And the head detects the old data (clock run signal
S _CL1 And index signal CDIX ₁ ] To “correct” data
As new data (clock run signal S _CL2 as well as
Index signal CDIX _Two ] Is ignored. As a result,
New data that should be read correctly is ignored and read
Unnecessary old data is incorrectly identified as “correct” data
There is a problem of being read.
Good was desired. Therefore, an object of the present invention is to read unnecessary old data.
And delete the necessary new data correctly.
To provide an information signal recording device that can be taken
is there. [Means for Solving the Problems] The present invention provides a magnetic head with a rotating magnetic
Tape runs at a constant speed diagonally over a range of corners
Video signals are supplied to the rotating magnetic head for a predetermined period.
And sequentially recorded on the magnetic tape as diagonal magnetic tracks
As it is recorded, the video signal is
Voice data section and index at positions not recorded
Sections are defined, and audio signals are
Without recording, the index
Helical scan type information signal that records the signal
Index section of a magnetic track
From the leading end of the clock run signal section
At the front of the track, a part of the track overlaps with the audio data section.
The index section and the clock run signal section
Carrier signal section that is longer than the added period
Is provided. [Operation] Carrier signal, clock run signal and index signal
Signal is output to the gate circuit for a predetermined period.
On the other hand, the gate timing signal turns on the gate circuit.
It is sequentially supplied to the gate circuit to turn it off. Gate
The period when the gate circuit was turned on by the timing signal
The carrier signal, clock run signal,
The dex signals are output and added respectively. As a result, the carrier signal, clock run signal, input signal
The dex signal is generated continuously in this order,
Supplied to the orderer. Bi-phase mark with encoder
After being modulated, it is placed on a magnetic track by a rotating magnetic head.
Be recorded. The length of the carrier signal section is the clock run signal section
Longer than the combined length of
Unnecessary clock run signals and indices previously recorded
Carrier signal (old data)
It can be completely erased by being written,
New clock run signal and index to be taken
The signal [new data] can be read correctly. 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 structure and recording / playback of VTR
Circuit operation (b) A clock signal arranged at the start end of the index section
From the end of the signal section to the beginning of the magnetic track.
(A) Outline of VTR configuration and recording / playback of VTR
Circuit Operation FIG. 1 shows a VTR as an information signal recording device.
This VTR is a camera-integrated VTR that does not record PCM audio signals.
It is. In FIG. 1, 55 controls the operation of this VTR.
System controller (hereinafter abbreviated as syscon)
Indicates a recording switch and a playback switch connected thereto.
By operating the mode switch 56 such as
5 corresponds to the mode switch 56 operated.
The operation mode is controlled. 34A and 34B are rotary magnetic heads (hereinafter simply referred to as heads).
The heads 34A and 34B are 180 ° apart from each other.
With an angular interval, the motor 62
Rotation at the system frequency
The magnetic tape 1 is inclined over an angle range of approximately 180 ° + 10 °
Is running at a constant speed. And this place
Although not shown, the rotational phases of the heads 34A and 34B are
At the time of recording, it is re-synchronized with the video signal to be recorded.
Servo so that the magnetic track 2 is scanned correctly at the time of raw
Controlled. Therefore, as shown in FIG. 2A, every other field
During the period Ta, the head 34A is in the beginning of the period Ta.
Scan section 158 and then section 28 of magnetic track 2
Scan. In every other field period Tb,
The head 34B scans the section 158 at the beginning of the period Tb.
Then, the section 28 of the magnetic track 2 is scanned. At the time of general recording, the color video signal S _C And mo
The normal sound signal Sm is supplied to the recording processing circuit 31. So
And the above-described FM luminance signal and the low-frequency-converted carrier color signal
Frequency multiplexed signal of FM voice signal and pilot signal
The signal Sf is continuously taken out as shown in FIG.
The signal Sf is supplied to the switch circuit 32. Also, for example, a pulse generating means 63 is provided on the rotating shaft 61.
Rotation phase of heads 34A and 34B for each rotation of heads 34A and 34B
A pulse Pg having a frame period indicating This pa
Lus Pg is supplied to the signal forming circuit 65 through the shaping amplifier 64.
And a rectangle that is inverted every period Ta and Tb as shown in FIG.
The wave signal Sw is extracted, and this signal Sw is supplied to the switch circuit 32.
It is supplied as the control signal. Switch circuit 32
With Ta and Tb, the state can be switched to the state opposite to the state shown in the figure.
You. Accordingly, as shown in FIG.
The signals Sf, Sf are alternately extracted for each of the periods Ta, Tb. Then, the signals Sf, Sf pass through the recording amplifiers 33A, 33B,
Further, through the recording side contact R of the switch circuits 67A and 67B,
It is supplied to heads 34A and 34B. Therefore, the magnetic tape 1
Indicates that the signals Sf, Sf are the video signal sections 28, 28 for each of the periods Ta, Tb.
Are sequentially recorded. Further, the signal Sw is supplied to the forming circuit 66, and the signal Sw shown in FIG.
As shown, the heads 34A, 34B
Is at “H” level during scanning of section 158
Pulse Ps is formed, and this pulse Ps is supplied to the recording processing circuit 51.
Is done. Also, the index signal CDIX controls the
The data is supplied from the controller 52 to the recording processing circuit 51. Meanwhile, the shape
In the circuit 66, the pulse Ps is based on its rising point.
6A period during which heads 34A and 34B scan section 158
It is formed to be at the “H” level over the interval.
This pulse Ps is supplied to the recording processing circuit 51 and is shown in FIG.
As shown in FIG. ₀₁ ,clock
Run signal S _CL And index signal CDIX is bi-phase
Converted to mark signal Ss and taken out from recording processing circuit 51
It is. Then, this signal Ss is transmitted during the field period Ta.
Recording processing circuit 51 → switch circuit 32 → recording amplifier 33B → switch
Head 34B through the signal line of the contact R of the switch circuit 67B.
And during the field period Tb, the recording processing circuit 51
→ Switch circuit 32 → Recording amplifier 33A → Switch circuit 67A
(Through the signal line of the contact R) to the head 34A.
You. Therefore, the magnetic track 2 has the carrier signal section 15
5 to carrier signal S ₀₁ Is recorded,
Clock run signal S _CL And index
Clock run signal S _CL And index
Issue CDIX is recorded. On the other hand, at the time of reproduction, the magnetic tracks are provided by the heads 34A and 34B.
As shown in FIG. 2G, signal Ss and signal Sf
The reproduced signals Ss and Sf are reproduced by each other.
Through the reproduction side contact P of the circuits 67A and 67B, the reproduction amplifier 3
The signal is supplied to the switch circuit 36 through 5A and 35B,
The signal Sw is supplied to the switch circuit 36 as its control signal,
When the signal Sf is continuously taken out from the switch circuit 36,
In both cases, the signal Ss is extracted for each field period. The signal Sf from the switch circuit 36 is
Original color video signal Sc and monaural sound supplied to 37
The voice signal Sm is extracted. Furthermore, the signal Ss from the switch circuit 36 is
53, the index signal CDIX is taken from the signal Ss.
This index signal CDIX is output to the controller 52.
Supplied and used for cueing. The above is the outline of the VTR configuration and the recording / playback time.
Road operation. (B) A clock signal arranged at the start end of the index section
From the end of the signal section to the beginning of the magnetic track
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
In the control signal forming circuit 90, the pulse Ps is
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. During recording, the heads 34A and 34B scan the section 157.
Index signal from the controller 52 during the
Signal CDIX is output, and this index signal CDIX is
When supplied to the buffer RAM 71 through the switch circuit 72,
At the same time, the address signal is
Supplied to the RAM 71 through the path 74, and thus recorded in the RAM 71.
The index signal CDIX to be performed is stored. Carrier signal S from the beginning of magnetic track 2 ₀₁ ,
Clan signal S _CL And the index signal CDIX
Mode (hereinafter referred to as dubbing mode)
The after-recording mode signal is selected by switch 56.
When applied to the controller 55, the control signal forming circuit 90
Is controlled. That is, as shown in FIG. 4 and FIG.
Gate timing signal to turn on / off the gate circuit 150
No.S _GT Ready to be supplied to the gate circuit 150.
It is. This gate circuit 150 has a gate timing signal S _GT By
Gates 152, 153, 154 that can be turned on and off, and addition times
Road 160. Pulse P mentioned above _S From the terminal 151 to the control signal forming circuit 90
When added, the gate timing signal S _GT Is the gate circuit 1
Output for 50. Gate timing signal S _GT of
Of which, gate timing signal S _GTa Over a 3H period
Port 152, and then the gate timing signal.
No.S _GTb Is the gate timing signal S _GTa Is set to “0”.
Sometimes the signal is output to the gate 153 during the rising 2H,
Gate timing signal S _GTc Is the gate timing signal S
_GTb Becomes 0 at the same time as rising for 1H.
Is output to the port 154. In this case, the head
34A and 34B from the beginning 162 of the clock run signal section 156
Carrier signal S from the previous 3H ₀₁ I have to start recording
The heads 34A and 34B run on the magnetic track 2
From the clock of the clock forming circuit 45 from the start of the
4 and 5 in accordance with the predetermined timing set in FIG.
As shown in the figure, the carrier signal S ₀₁ [Continuation of “01”] and
Lock run signal S _CL [All “1”] are carrier and prior
It is output from the amble forming circuit 81. As described above, the gate timing signal S _GTa But over 3H
Output to the gate 152, during which time the gate 152 is turned on.
The carrier signal S as shown in FIG. 5A.
₀₁ Is output continuously during the 3H period.
Circuit 160 is reached. Next, the gate timing signal S _GTa Is set to “0”.
Sometimes gate timing signal S _GTb During the 2H rise
It is output to the gate 153 and the gate 153 is turned on during this time.
Clock run as shown in FIG. 5B.
Signal S _CL Is output continuously during the 2H period, and is output to the addition circuit 160.
Reach. In the adder circuit 160, the capacitors sequentially output and supplied are
Rear signal S ₀₁ [3H], clock run signal S _CL [2H] continuous
Generated in the state, sequentially output and post-recording signal S _AF And
The after-recording signal S generated in this way _AF Is Enko
Encoder 85 to the bi-phase mark signal Ss.
This signal Ss is output to the switch circuit 32,
And it is recorded. Further, the gate timing signal S _GTb Becomes “0” at the same time
Gate timing signal S _GTc Rises for 1H
Output to the gate 154, during which the gate 154 is turned on.
The index signal as shown in Fig. 5C.
The signal CDIX is ready to be output for 1H. H
34A and 34B are clock run signals S _CL Recorded section of 156
Immediately before passing through 2H, the address forming circuit 73 switches
An address signal is supplied to the RAM 71 through the
The index signal CDIX is read and the index signal
No. CDIX is supplied to the register 83 through the switch circuit 72.
From a parallel signal to a serial signal. This
The realized index signal CDIX is converted to the CRCC forming circuit 84.
The CRC code is added to the
The added index signal CDIX passes the gate 154 described above for 1H.
, And reaches the adding circuit 160. Addition times
In the path 160, the sequentially output and supplied carrier signal S
₀₁ [3H], clock run signal S _CL [2H], index
Generates the signal CDIX [1H] in a continuous state and outputs it sequentially to 6H
Post-recording signal S output across _AF And like this
After-recording signal S generated as shown in FIG. 5D _AF [6
H] is supplied to the encoder 85 and the bi-phase mark
The signal Ss is encoded, and this signal Ss is
Output to and recorded. The recording in the after-recording mode is shown in FIG. 6A.
As described above, the magnetic tape
6 Under the 6H recording pulse shown in FIG.
Are performed in the order in which they are output. That is, the tip of the recording pulse
3H in carrier signal section 155, followed by clock run signal
No.S _CL Is 2H, and the index signal CDIX is 1H.
Each is formed. Then, as shown in FIG.
Black run signal S _CL Clock run by 1.5H in the first half
A signal interval 156 is formed, and the second half 0.5H and index
Index section 157 is formed by 1H of the index signal CDIX
Is done. 161 is the start of the index section 157, 162 is
The end of the clock run signal section 156 and 163
A The end of the signal section 155. Then, each section 15 described above
5,156,157 have carrier signal S ₀₁ Clock run
Signal S _CL , Index CDIX is recorded. On the other hand, during playback, data is read first from the heads 34A and 34B.
Carrier signal S ₀₁ Is a long section of at least 3H
Has been recorded over. Therefore, previously recorded
Index signal CDIX ₁ And clock run signal S _CL1 Etc.
Even if there is old data, this old data is
Within the range of deviation allowed by the standard (± 1.5H)
As long as the carrier signal S ₀₁ Overwritten by
It is something. Therefore, as shown in FIG. 6C, the heads 34A and 34B
Clock run signal S as new data _CL And index
Read the data signal CDIX, resulting in the required data
Will read the data correctly. In this embodiment, the carrier signal section is set to 3H.
However, the present invention is not limited to this.
Between the index section (1.5H in this embodiment) and the clock
Added the clan signal section (1.5H in this example)
Needless to say, it may be longer than the period. The circuit operation during reproduction is as follows. The signal Ss from the switch circuit 36 is supplied to the decoder 86.
The index signal CDIX is decoded by
The signal CDIX is supplied to the CRCC check circuit 87 to
Error check of the index signal CDIX
Will be Then, the index signal CDIX from the check circuit 87
Is supplied to the register 88 to convert the serial signal to the parallel signal.
Signal, and this parallelized index signal
CDIX is written to the RAM 71 through the switch circuit 72.
At this time, the address forming circuit 73 switches the switching circuit
The address signal is supplied to the RAM 71 through 74. 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,
Is performed. [Effects of the Invention] In the present invention, the magnetic tape is recorded and formed on
At the beginning of the index section of the magnetic track
From the beginning of the magnetic track
Index section and clock run signal section toward the end
Carrier signal section that is longer than the added period
Is provided. Therefore, according to the present invention, the length of the carrier signal section
Means that the clock run signal section and index section
Clock run signal and input
Even if the dex signal (old data) is recorded, the carrier
New clock over which the signal is to be overwritten and read
Read run and index signals correctly
There is an effect that can be.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of an entire circuit showing one embodiment of the present invention, FIG. 2 is a timing chart of the circuit shown in FIG. 1, and FIG. 3 is a process shown in FIG. 4 is a block diagram of the gate circuit shown in FIG. 3, FIG. 5 is a timing chart of the gate circuit shown in FIG. 4, and FIG. 6 is a magnetic track. FIG. 7 is a schematic diagram showing a conventional track format, and FIG. 8 is a schematic diagram showing a postamble section shown in FIG. FIG. 9 is a schematic diagram showing a partially enlarged explanatory view of a recording format showing the configuration, and FIG. 9 shows a state in which a plurality of clock run signals and index signals are recorded on the same track. Description of main reference numerals in the drawings 1: magnetic tape, 2: magnetic track, 157,242: index section, 34A, 34B: rotating magnetic head, 150: gate circuit, 155:
Carrier signal section, 156: Clock run signal section, 158: Dubbing section, 161: Start point, 162,163: Tip, S _CL : Clock run signal, CDIX: Index signal, S ₀₁ : Carrier signal, S
_AF : After-recording signal.

Continuation of the front page (56) References JP-A-62-172572 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G11B 20/12-20/12 103 G11B 5/02

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 a video signal is supplied to the rotary magnetic head for a predetermined period, and a magnetic track is tilted on the magnetic tape. Are sequentially recorded, and an audio data section and an index section are defined at positions where the video signal is not recorded in the magnetic track, and the audio signal section is not recorded in the audio data section, and the index is not recorded. In a helical scan type information signal recording apparatus in which an index signal is recorded for a section, a front side of the magnetic track is provided from a tip of a clock run signal section arranged at a start end side of the index section of the magnetic track. Then, the index section and the clock are so set that a part thereof overlaps the audio data section. An information signal recording device, comprising: a carrier signal section which is longer than a period including a run signal section.