JPS63104269A - Magnetic recording device for information signal - Google Patents

Abstract

PURPOSE:To facilitate a program searching and editing at the time of reproduction by recording/reproducing index signals of a prescribed content in the overlapping part at the end part of an information track in a helical scanning type VTR such as 8mm video device. CONSTITUTION:During the time when a head is scanning, the scanning end block of rotary head following a magnetic track, index signals of such as recording data, absolute location, program number, etc., for an information signal are supplied to the head, to let the head record these signals in a scanning end block. That is, said index signals are recorded and reproduced in the leading end parts 291, 292 of a head scanning end block 29 following a video track block 28, so that the blocks 291, 292 will not be influenced even when PCM signals are post-recorded with other 8mm video device. As a result, the program searching and the editing operations of the video is made extremely convenient.

Description

[Detailed description of the invention] The explanation will be given in the following order.

A. Field of industrial application B. J1!11 requirements for the invention C. Prior art D. Problem to be solved by the invention E. Means for solving the tin problem (Figure 1) F
Effect G Embodiment G1 First embodiment (FIGS. 1 to 5) G2 Other embodiments H Effect of the invention A Industrial application field The present invention relates to a VTR and the like.

B. Summary of the Invention This invention is a helical scan type VTR such as 8 mm video, by recording or reproducing an index signal having a predetermined content in an overlapping portion at the end of an information trunk. This is an expanded version of its functions.

C. Prior Art The trunk format of magnetic tape for 8 mm video is defined as shown in FIG.

That is, in the same figure, (1) is a magnetic tape, (2)
denotes a magnetic track, which trunk (2) is formed obliquely to the tape +11 by means of two rotating magnetic heads with an angular spacing of 180° to each other and corresponding to a rotation angle of 221° of the rotating heads. formed or scanned in length.

Then, from the tip of the track (2), 36
The section (2S) corresponding to a rotation angle of 185 degrees is used for audio signals, and the remaining section (2v) corresponding to a rotation angle of 185 degrees is used for video signals.

The audio trunk (2S) is divided into sections (21) to (25) as shown in the figure, and section (21) is the scanning start section of the rotating head (head entry section), section (22
) is a preamble section where clock run-in is recorded and played back, (23) is an audio data section where a PCM audio signal is recorded and played back, (24) is a postamble section for back margin used during after-recording, Section (2
5) is a truck (2S).

This is a guard interval for (2v).

In addition, in this case, the PCM audio signal in section (23) is 1
The stereo audio signal for the field period is time-base compressed and converted into a PCM signal, and has an error correction code, an ID code, and the like. Then, the interval (22) to (2
When the value of the signal 4) is "0", the signal 2. ! J.M.H.
When K is "1", it is recorded after being converted into a 5.13 MHz pi-phase mark signal.

Furthermore, the video track (2v) has a guard section (25)
It is then divided into a section (28) corresponding to a rotation angle of <180° and a section (29) corresponding to a remaining rotation angle of 5°,
In the section (28), an FM signal modulated by a luminance signal, a carrier color signal subjected to low-frequency conversion, an FM signal modulated by a monaural audio signal, and a pilot signal are included in one of the frequency-divided signals. The field is recorded and played back. Furthermore, the section (29) is the scanning end section of the rotating head (head separation section).

(Literature: "Television Society Journal" Vol. 29, No. 4, etc.) D. Problem to be solved by the invention According to the above format, the audio data section (23)
Since an ID code is recorded at the same time as the audio signal, various data such as the recording date,
Absolute positions, program numbers, etc. can be recorded, making it extremely convenient for editing by locating the beginning during playback.

However, in 8mm video, the audio signal is converted to PCM.
The function of recording the signal state on the track (2S) is optional. For 8mm videos that do not record or reproduce tracks (2s), the track format is divided into sections (2s) as shown by the broken line in Figure 7.
22) to (25) are absent.

Therefore, with 8mm video without this optional function, ID:7-code cannot be recorded and played back, so of course it is not possible to cue up when replaying, and further functions cannot be realized, such as editing and saving. It was also inconvenient.

This invention attempts to solve these problems.

E. Means for solving the problem Here, speaking about the section (29) of the trunk (2ν), in this section (29), the rotary head that had been scanning the trunk (2) until now is moving from the tape (11 Therefore, near the start of the section (29), the rotary head is scanning the section (29) while still being in sufficient contact with the section (29).

This section (29) has a length corresponding to 5 degrees of the rotating head, but when converted into a length of time, the rotation angle of 18 degrees is 262.5 hours (1 horizontal period of IH). Therefore, the time length of section (29) is equal to .

Therefore, even if the rotary head finishes scanning the video signal track (28) and moves on to the following section (29), the section (29)
) is scanned normally for several horizontal sections from the tip.

The present invention focuses on such a point and records or reproduces an index signal near the tip of the section (29).

F Effect A cue signal for cueing and absolute position information are played.

G Embodiment G1 First Embodiment Let us now explain the recording format of the index signal. As mentioned above, section (29) of track (2)
) is approximately 7.3H long, and the rotary head is scanning normally in the section several H from the tip, so as shown in Figure 4, 1 from the tip of section (29). The interval (291) of .5H and the interval (292) of continuation < 1.5H are defined as index signal intervals.

As shown in Figure B, in the case of format A, section (291) is assumed to have no signal (no recording),
292) is all “1” in the 0.5H section from the tip.
” is recorded, and all “O”s are recorded as the cue index signal CUIX in the remaining IH section.

All "1"s are recorded as the signal C old X.

In addition, in the case of format C, formats A and B
In place of the cue index signal CUIX, a coding index signal CDTX (details will be described later) is recorded.

Furthermore, in the case of formats) D, F, the interval (29
1> is made equal to the interval (292) of formats A and H, and the interval (292) is made equal to the interval (292) of format C.

Then, the coding index (i3+CDIX) is the block BLK as shown in C of the same figure.
I~BLX6 and its end code Rr! Furthermore, as shown in the same figure, blocks BLKI~
BLKG is a 3-bit mark code and an 8-bit ID.
Codes IDO to ID4 and their 8-bit C
It is divided into RC codes.

In this case, the ID codes ID0-104 are the same as the tD codes TDO-ID4 that are recorded simultaneously with the PCM audio signal when the PCM audio signal is recorded in section (23), and the tape! 11, the cut number for each cut of the recorded content, the year, month, day, and hour, minute, and second of recording.

Also, the signals in these sections (291) and (292) are similar to the signals in the audio track (2S),
2.9MHz when it is 0'', 5 when it is ``1''
．． It is recorded after being converted to a high phase mark signal of 8 MHz.

The above formats are used in any one of types I to II, depending on the grade of the VTR.

That is, as shown in FIG. 5, it is assumed that the recording on the tape 11 is divided into a plurality of cuts (the term "cut" here also includes the concept of chapters on video discs, etc.). Then, in the case of type (2), as shown in FIG. B, the index signal is recorded in format l-A for, for example, 10 seconds from the beginning of each cut, and the index signal is recorded in format B for the remaining period. Therefore, this type {circle around (2)} can be used to cue each caputo by determining @I Q Il, "l" in a lower model (low-cost machine).

In addition, in the case of type ■, as shown in Figure C, index signals are recorded alternately for each track (2) in formats A and C for, for example, 10 seconds from the beginning of each cut, and the remaining period is in format A and C. Track B and C (2
), index signals are recorded alternately. Therefore, according to Kouib H, in lower models,
Each cut can be played by distinguishing between "0" and "】" of the index signal CIIIX, and in higher models, the index (No. 11 CDIX (7) ID: 7-does ID0-ID5 is checked). This allows information such as absolute addresses to be obtained.In other words, it is compatible with lower and higher model models.

Furthermore, in the case of type ■, as shown in the same figure, the index signal is recorded in format D for, for example, 10 seconds from the beginning of each cut, and the index signal is recorded in format E for the remaining period.
The index signal is recorded. Therefore, according to this type (2), in the lower model, the index signal CUIX is "O".

By determining “1”, you can locate the beginning of each cut.
In lower models, rD code I of index signal CDIX
Information such as absolute addresses can be obtained by checking DO to ID5, and it is also compatible with lower and higher model models.

Next, an example of an 8 mm video that implements the above-mentioned index signal and recording format will be explained.

In FIG. 1, (34^) and (34B) indicate rotating magnetic heads, and these heads (34A) and (34B
) have an angular spacing of 180° from each other, and the rotation axis (5
1), the magnetic tape +1+ is rotated at a frame frequency by a motor (52), and the magnetic tape +1+ is run diagonally at a constant speed over an angular range of approximately 188 degrees with respect to its rotating circumferential surface. In this case, although not shown, the heads (34A) and (34B)
The rotational phase of is servo-controlled so as to synchronize with the video signal to be recorded during recording, and to correctly scan the trunk (2) during playback.

Therefore, as shown in FIG. 2A and FIG. 7, in every other field period Ta, the head (34A) scans the section (28) of the track (2), and the period T
In several horizontal periods before and after a, the head (34^) is in the section (28
), and in every other remaining field period Tb, the head (
34B) scans the section (28) of the trunk (2), and the head (34B) scans the section (28) of the trunk (2), and the head (34B
> is the interval (21) before and after the interval (28).

(29) will be scanned.

And when recording, color video @! The signal Sc and the monaural audio signal Ss are supplied to the recording/reproduction processing circuit (31), where they are frequency-multiplexed with the above-mentioned FM luminance signal, the low-frequency converted carrier color signal, the FM audio fl, and the pilot signal. The signal sr is continuously taken out as shown in FIG. 2B, and this signal Sf is supplied to the switch circuit (32).

Further, for example, a pulse generating means (53) is provided on the rotating shaft (51).
is provided, and a pulse Pg having a frame period indicating the rotational phase of the head (34^), (34B) is taken out for each rotation of the head (34^), (34B), and this pulse Pg
is supplied to the signal forming circuit (55) through the shaping amplifier (54), and a rectangular wave signal Sw which is inverted every period Ta and Tb as shown in FIG. This is supplied as a control signal, and the switch circuit (32) is switched between the state shown in the figure and the state opposite to that shown in the figure during periods Ta and Tb. Therefore, as shown in the figure, the switch circuit (32) outputs the signals St,
Sf is taken out alternately every period Ta and Tb.

Then, these signals Sf and Sr are sent to the recording amplifier (338).
(33B), furthermore, the switch circuit (61A)
, (61B) are supplied to the heads (34A) and (34B) through the recording side contacts R. Therefore, as shown in FIG. 7, the tape (1) has a period Ta.

The signals Sr and Sf are video signal sections (2B) for each Tb.

(28) are sequentially recorded.

Furthermore, the signal SW is supplied to the forming circuit (43) to
As shown in Figures E and F, the pulse Pi remains at the "11" level for 1.5 horizontal periods from the end of periods Ta and Tb, and the pulse Pj remains at the "H" level for the next <1.5 horizontal periods. These pulses Pi to Pj are supplied as timing signals to the conversion circuit (42).

Although the details will be described later, this conversion circuit (42) uses a cue signal for cueing or a 1D signal corresponding to formats A to F.
The code is converted into an index signal "4curx" to "cnrx" having a preamble during the period from Pi='"H" to Pj-'H.

The cue signal or ID code to be converted is
It is supplied from a controller (microcomputer) (41) that manages these.

Therefore, from the conversion circuit (62), the format A-
Corresponding to F, the period from Pi = "H" to Pj = "H',
That is, the index signals CUIX to C port IX are taken out during the period when the head (34A) or (34B) is scanning the section (291) or 292).

This index signal is then supplied to the encoder (43) and encoded into a pie-phase mark signal sb, and this signal sb is supplied to the switch circuit (32). Therefore, from the switch circuit (32), type l
, ■, as shown in Figure G, the periods Ta, Tb
The signals Sf and Sf are followed by the signal sb after 1.5 horizontal periods,
The sb is taken out and the head (34A), (34
B), and in the case of type (2), as shown in H in the figure, the signal sb is taken out following the signals Sf and Sr of periods Ta and Tb, and the signal sb is supplied to the heads (34A) and (34
B).

Therefore, the video signal Sf is recorded in the section (28) of the track (2), and the index signals CUIX to C(II
X is recorded.

On the other hand, during playback, the heads (348) and (34R) output the signal Sf and signal sb from the track (2) to G in the same figure.
Or field period Ta as shown in H.

Tb is alternately reproduced, and this reproduced signal Sf&
and sb are switch circuits (61^), <61B)
Further, through the playback side contact P of the playback amplifier (35^).

(35B) to the switch circuit 1i (36), the signal 3w is also supplied to the switch circuit (36) as its control signal, and the signal Sr is continuously taken out from the switch circuit (36). sb is retrieved for each field period.

Then, the signal Sr from the switch 1/3 (36) is supplied to the processing circuit (31) and the original color video signal Sc
and monaural audio signal Ss are extracted.

Further, the signal sb from the switch circuit (36) is supplied to the decoder (44) to decode the index signal CUIX or CDIχ, and this signal is sent to the conversion circuit (45).
and error correction is performed on the queue 1.
8 or an ID code, which is supplied to the controller (41) and used for processing such as cueing, absolute position, and cut number.

Thus, according to the present invention, index signals can be recorded or played back even in 8 mm videos where PCM audio signals cannot be recorded or played back, and cueing and editing can be performed conveniently.

In that case, especially according to the present invention, the index signal is recorded and reproduced near the tip (291) (292) of the head scan end section (29) following the video track section (28), so that other PCM with 8mm video
Even if the audio signal is after-recorded, the section (291
), (292') are not affected by this, and therefore, the video tmf? recorded in the video signal section (2B). Data such as the recording time of the i-number Sc and the audio signal S9 are not erased or destroyed, and are retained in correct correspondence with the recorded contents. Furthermore, it is compatible with other 8 mm videos in terms of video signal Sc and audio signal Ss.

Furthermore, since the scan end section (29) is formed in any 8mm video, the mechanism can remain the same, and the circuits (41) to (45) can also be used for 8mm video that can record and play back PCM audio signals. ICs used for video can be used as they are, so index signals can be recorded and reproduced at low cost. Furthermore, for the same reason, index signals can be recorded even with a small and lightweight recording-only machine.

Also, during variable speed playback, the head (34^), (34B)
, will cross the trunk (2) diagonally, but since the sections (291) and (292) are as short as 1.5 horizontal sections, for example, even during search playback at 30 times the section (291)
).

Head (34A), (34B) for (292)
) are scanned almost in parallel or with almost correct tracking, and the index signal can be reliably reproduced.

FIG. 3 shows an example of the conversion circuits (42) and (45), in which the portion indicated by the chain line is the circuit (43).

(44) and is integrated into a single chip IC.

That is, in the figure, (61) represents a clock forming circuit, (62) represents a control signal forming circuit, and this forming circuit (
At 62), various control signals are formed at predetermined timings based on the pulses Pi to Pj, and these control signals and the clock of the forming circuit (61) are supplied to the respective circuits.

During recording, the index signal ctl is sent from the controller (41) during a period when the heads (34^) and (34B) are not scanning the section (291) or 292).
IX or CDIX is output, and this index signal is sent to the buffer RAM (63) through the switch circuit (63).
64), and the address signal is sent from the controller (41) to the RAM via the switch circuit (65).
<64), and therefore the index signal to be recorded is stored in the RAM (64).

Then, head (348), (34B> is section (291)
) to 292), the pulses Pi to Pj become H" at this time, so a preamplule signal is output from the preamble forming circuit (71) for 0.5 horizontal period, and this preamplule 4 'F'f is supplied to the encoder (43) and encoded into a pi-phase mark signal sb, and this signal Sb is sent to the switch circuit (
32).

Subsequently, when the heads <34A) and (34B> pass through the 0.5 horizontal interval of the interval (291) or 292), an address signal is sent from the address forming circuit (66) to the RAM (64) through the switch circuit (65). is supplied, the index signal CUIX or CDIX is read out, and this index signal is sent to the switch circuit (63).
The serialized index signal is supplied to the register (72) through CI?, where it is converted from a parallel signal to a serial signal. The index signal to which the CRC code is added is supplied to the CC forming circuit (73), and the index signal to which the CRC code is added is supplied to the encoder (43) and converted into the signal sb.
3 (32).

Therefore, preamble and index signals are recorded in sections (291) to 292) corresponding to types 1 to 2.

On the other hand, during playback, the signal 3 from the switch circuit (36)
b is supplied to a decoder (44) to decode the inte-nox signal, and this index signal is supplied to a CRCC check circuit (74) to perform an error check on the index signal using a CRC code. in this case,
Heads (34A) and (34B) are section (29
When scanning a section other than 1) or 292), signals other than the signal sb are supplied to the decoder (44), but only the correct index signal is taken out from the check circuit (74). Timing by pulses Pi to Pj is not required.

Then, the index signal from the check circuit (74) is supplied to the register (75) and converted from a serial signal to a parallel signal, and this parallelized index signal is sent to the RAM (64) through the switch circuit (63).
will be written to. At this time, the address signal is supplied from the formation circuit (66) to the RAM (64) through the switch circuit (65).

When writing of the index signal is completed, the address signal is supplied from the controller (41) to the RAM (64) through the switch circuit (65) and the index signal is read. 11!3 (63): is taken into the controller (old), and thereafter its index f8
Processing corresponding to the number, such as cueing, is performed.

G2 Other Examples Note that the above is a case of 8 mm video, but
The present invention can be applied to any helical scan type VTR such as BetaF or f-mat VTR. It can also be applied to a multi-trunk machine that divides the video signal section (28) into a plurality of sections and records or reproduces information signals such as PCM audio signals and still image video signals in the divided sections. Furthermore, other index signals can also be recorded and reproduced in section (291) in format A-C.

Effects of the Invention According to this invention, index signals can be recorded or played back even in 8mm videos where PCM audio signals cannot be recorded or played back.
i etc. can be done conveniently.

In that case, particularly according to the present invention, the index signal is transmitted near the tip (291) of the head scan end section (29) following the video track section (28).

(292), so even if the PCM audio signal is after-recorded with another 8mm video, the sections (291) and (292') will not be affected by it, and therefore the video signal section (292') will not be affected. 28) Data such as the recording time of the video signal Sc and the audio signal Ss is not erased or destroyed, and is maintained in correct correspondence with the recorded contents. It is also compatible with other 8mm videos in terms of video 4N Sc and audio 4tJ S.

Furthermore, since the scanning end section (29) can be formed in any 8mm video, the mechanism can remain the same as before, and the scanning end section (29) can be used as an 8mm video that can record and play back PCM audio signals. The IC used for millivideo can be used as is, so index signals can be recorded and played back at low cost. Furthermore, for the same reason, index signals can be recorded even with a small and lightweight recording-only machine.

Also, during variable speed playback, the head (34A), (
34B) crosses the track (2) diagonally, but the sections (291) and (292) are as short as 1.5 horizontal sections, so even during search playback at 30x speed, for example, the section (291).

With respect to (292), the heads (34^) and (34B) scan almost in parallel or with almost correct tracking, so that the index signal can be reliably reproduced.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of an example of the present invention, and FIGS. 2 to 7 are diagrams for explaining the same. (31) is a recording/reproduction processing circuit, (42), (45
) is a conversion circuit.

Claims (1)

[Claims] A magnetic tape is run obliquely at a constant speed over a predetermined angular range with respect to the rotating circumferential surface of a rotating magnetic head, and an information signal is supplied to the rotating magnetic head for a predetermined period of time. In a helical scan type magnetic recording device that sequentially records on a tape as diagonal magnetic tracks, when the rotary magnetic head is scanning a scan completion section of the rotary magnetic head following the magnetic track, the rotary magnetic head A magnetic recording device for information signals, wherein an index signal related to the information signal is supplied to a head, and the index signal is recorded in the scan end section.