JPS63106962A - Magnetic recording device for information signal - Google Patents

Abstract

PURPOSE:To obtain a correct index signal without setting an index signal in an old index signal interval as valid, by providing the index interval at a position where no information signal is recorded, and attaching and recording a start code or an end code of specific bit pattern at the start terminal or the end terminal of the index signal. CONSTITUTION:Since the index signal CDIX is recorded at a part 242 of a postamble interval 24, a required ID code can be obtained immediately at time of search reproduction, however, at this time, the end code IENC is attached at the last position of the index signal CDIX. Therefore, at time of reproduction, by prohibiting the reproducing processing of the index signal CDIX for a prescribed period from the end code IENC, even when the old index interval 242 following a new index interval 242 is left, the index signal CDIX of the old index signal interval 242 is not validated, and the correct index signal CDIX can be obtained.

Description

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

A. Field of industrial application B. Overview of the invention C. Prior art D. Problem to be solved by the invention E. Means for solving the problem (Fig. 1) F. Effect G. Example GX First implementation IjIJ 1 to 4) G2 Other Embodiments (FIGS. 5 to 7) H Effects of the Invention A Industrial Application Field This invention relates to a magnetic recording device for information signals.

B. Summary of the Invention The present invention records an index signal separately from the information signal on a recording track of the information signal in a magnetic recording device for an information signal such as an 8 mm video, and records the index signal separately from the information signal. A code signal indicating this is added to the start or end of the line.

C. Prior Art The track format of a magnetic tape for 8 mm video is determined as shown in FIG.

That is, in the same figure, (1) is a magnetic tape, (2)
indicates a magnetic trunk, this track (2) is formed obliquely to the tape (1) and at a rotation angle of 221° of the rotating heads by two rotating magnetic heads having an angular spacing of 180° from each other. The corresponding length is formed or scanned. Then, from the tip of the track (2), a section (2S) corresponding to a rotation angle of 36° of the rotary head is used for audio signals, and a remaining section (2V) corresponding to a rotation angle of 185°.
is used for video signals.

The audio track (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 the preamble section where the clock run-in is recorded and played back, (23) is the audio data section where the PCM audio signal is recorded and played back, and (24) is the postamble section for bank margin during after-recording.
) is a truck (2S).

This is a guard interval for (2v).

In addition, in this case, the PCM audio data of section (23) is
A stereo audio signal for one field period is time-base compressed and converted into a PCM signal, and is also converted into a signal having an error correction code, an ID code, and the like. And the interval (
The signals 22) to (24) are converted into pi-phase mark signals of 2.9 MIIz when the value is "0" and 5.8 MHz when the value is '1' and then recorded.

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), one field of a frequency multiplexed signal of 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 is included. Recorded and played back. Furthermore, the section (29) is the scanning end section of the rotating head (head separation section).

According to such a format, the audio data section (2
3) Since an ID code is recorded at the same time as the audio signal, various data such as recording date, absolute position, program number, etc. can be recorded as this ID code, which is extremely useful for cueing and editing during playback. It's convenient.

However, when the ID code is recorded in the audio data section (23), it is recorded while being dispersed within the section (23) by interleaving together with the PCM audio data. Therefore, in order to correctly reproduce the ID code, the section (23
) must be correctly scanned by the rotating head over a considerable length.

However, during search playback, the tape (1) runs at, for example, 30 times the speed of recording, so the rotating head moves in the section (
23), and therefore, during search playback, it may not be possible to correctly play back the 10 codes for a considerable period of time.

Therefore, the postamble section of the audio trunk (2S) (
24) is considered to record and reproduce an index signal such as an ID code.

That is, this section (24) is 2.06 of the rotating head.
The length is equivalent to 1°, but when converted to the length of time, the rotation angle of 180° is equal to 262.5H (IH is 1 horizontal period), so the time length of section (24) is: Become.

Therefore, for example, as shown in FIG. 9A and B, the section (24
) in the first half of 1.5H section (241) and the remaining second half of 1.5H section (241)
, 5H interval (242) are taken as index signal intervals. As shown in C in the same figure, the section (241) has no signal (no recording), and the section (242) has a preamble signal of all "1" recorded in the section o, si■ from its tip. The coding index signal CDIX is recorded in the remaining IH section.

Then, the coding index signal CDIX is generated from blocks BLKI to BLKI as shown in the figure.
It is equally divided into BLK6 and backup program BAUX, and furthermore, as shown in the same figure, blocks BLKI to BLK6
is a 3-bit mark code and an 8-bit ID code I.
It is divided into DO to ID4 and 8-bit CRC codes for them.

In this case, blocks BLKI to BLK6 correspond to modes 1 to 6 to which IDO to ID4 recorded in the PCM audio data section (23) belong, and ID codes ID0 to I
D4 is the ID code IDO~ recorded in section (23)
It is the same as ID4, and is a signal such as the absolute position on the tape (1), the cut number for each cut of the recorded content, the year, month, day, hour, minute, and second of recording.

Also, the index signal CDT in the section (242)
X is “0” like the signal in the audio track (2S)
2.9M1lzS" When 1", 5.
It is recorded after being converted into a pi-phase mark signal of 8 MHz.

According to such a recording format of the index signal CDIX, during variable speed playback, the rotary head will move to track (2).
Although it crosses diagonally, the section (242) is 1.5
Since the horizontal section is short, for example, even during search playback at 30x speed, the rotating head scans almost parallel to section (242), or tracks almost correctly, and the index signal CDIX (ID code) is reliably scanned. Can be played.

Also, the meaning of the ID code differs depending on the mode 1 to 6, so when using the ID code recorded together with the PCM audio data in section (23), six tracks must be played. , 6 field periods are required, but according to the above format, all the ID codes of modes 1 to 6 are recorded as the index signal CDIX in one section (242), so the section (242) Just by playing one horizontal section of (, you can immediately obtain the necessary ID code.

Furthermore, after recording the video signal Sc and the audio signals R and R, only the index signal CDIX can be recorded independently, and for example, a chapter number etc. can be attached to the edited tape (1).

(References: Japanese Patent Application No. 60-64554 and Japanese Patent Application No. 60-1
No. 61438, etc.) D Problems to be Solved by the Invention However, if the index signal CDIX is recorded in the postamble section (24) as described above, the PCM
You can perform after-recording of the audio signal or record the section (24
If the index signal CDIX in 2) is rewritten, trouble may occur.

In other words, Figure 10A is a flexible version of the starting ends of the audio trunk (2S) and video trunk (2v) in Figures 8 and 9A, but this is just a standard recording format. . In an actual VTR, when a PCM audio signal is after-recorded, due to mechanism errors and signal timing errors, sections (22) to (24) are completely tracked, as shown in Figure B. (28) side, or, as shown in FIG. Furthermore, when recording PCM audio signals at the same time as video signals, the positions of sections (22) to (24) may shift due to similar errors, as shown in B and C in the same figure. 22)～(
Even if the track (24) shifts toward the track (28), the track (2
A guard section (25) is provided to prevent this from reaching 8).

Therefore, for track (2) on which recording is currently being performed with sections (22) to (24) being shifted as shown in FIG. If a PCM audio signal is after-recorded using a VTR that performs recording with a shift as shown in the figure, the recording result will be as shown in the same figure. In other words, new sections (22) to (24) are formed by after-recording, but
At this time, a new section (24) and a video trunk (28) are created.
), the old section (24), especially the section (242), remains.

When the rotary head scans such a track (2), a new index signal CDIX is obtained from the new section (242), and an old index signal CDIX is obtained from the old section (242), so that the index signal CDIX If you use it to perform various controls, problems will occur.

This invention attempts to solve these problems.

E. Means for Solving the Problems Therefore, in the present invention, a start code or encode of a specific bit pattern is added to the index signal CDIX recorded in the section (242).

F During playback, the old index signal CDIx is ignored due to the start code or end code.

G Example G1 First Example In FIG. 1, (34A) and (34B) indicate rotating magnetic heads;
34B') have an angular spacing of 180° from each other, are rotated at a frame frequency by a motor (62) through a rotating shaft (61), and the magnetic tape (1) is rotated at an angle of approximately 221° with respect to its rotating circumferential surface. is run diagonally at a constant speed over an angular range of . In this case, although not shown, the heads (34A) and (34B
) is servo-controlled so as to synchronize with the recorded video signal during recording and to correctly scan track (2) during playback.

Therefore, as shown in FIG. 2A and FIG. 8, in every other field period Ta, the head (34A) scans the section (28) of the track (2), and the period T
During the 115 field period before a, the head (34A) scans the section (2S) before the section (28), and also scans the remaining 1 field.
In the second field period Tb, the head (34B) scans the section (28) of the track (2), and in the 115 field period before the period Tb, the head (34B) scans the section (28) before the section (28). The section (2S) will be scanned.

At the time of recording, the color video signal Sc and the monaural audio signal Sm are supplied to the recording processing circuit (31), and the above-mentioned FM luminance signal and the low frequency-converted carrier color signal are processed.
A frequency multiplexed signal Sf of the FM audio signal and the viroft signal is successively extracted as shown in FIG. 2B, and this signal Sf is supplied to the switch circuit (32).

Further, for example, a pulse generating means (63) is provided on the rotating shaft (61).
are provided with heads (34A) and (34B)
Head (34A), (3411) for each rotation of
A pulse Pg with a frame period indicating the rotational phase of is extracted, and this pulse Pg is supplied to a signal forming circuit (65) through a shaping amplifier (64) to form a rectangular shape 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) as its control signal, and the switch circuit (32) operates during periods Ta and T.
b is used to switch between the state shown in the figure and the state opposite to that shown in the figure. Therefore, the signals Sr and Sf are alternately taken out from the switch circuit (32) during periods 'l'a and 'l'b, as shown in the figure.

Then, these signals Sf and Sf are sent to the recording amplifier (33A).
, (33B), and the switch circuit (67
It is supplied to the heads (34A) and (34B) through the recording side contacts R of A) and (67B). Therefore, as shown in FIG. 9, tape (1) has a period Ta.
.

Signals sr and sr are video signal sections (2B) for each Tb.

(28) are sequentially recorded.

Furthermore, the stereo audio signal R is a recording processing circuit (41
), and the ID code (index signal CDIX) is supplied to the controller (52) that manages the ID code (index signal CDIX).
is supplied to the processing circuit (41).

Further, the signal Sv is supplied to the forming circuit (66), and as shown in FIG. 2E, the head (
34A) and (34B) are sections (22) and (23
) is the pulse pa that becomes “H” level during the scanning period.
is formed, and this pulse Ps is supplied to the processing circuit (41), and as shown in FIG. After being axially compressed and converted into a PCM signal, and a preamble signal of section (22) is added, it is converted into a pi-phase mark signal Sp and extracted.

This signal Sp is transmitted from the OR circuit (42) to the switch circuit (32) to the amplifier (33) during the field period Ta.
B) → is supplied to the head (34B) through the signal line of contact R of the switch circuit (67B), and during period Tb,
OR circuit (42) - switch circuit (32) → amplifier (3
3A) - is supplied to the head (34A) through the signal line of contact R of the switch circuit (67A). therefore,
The track (2) has a signal Sf in the video signal section (28).
Prior to recording the signal Sp, that is, the preamble signal and the PCM audio data, are recorded in sections (22) and (23).

Also, the index signal CD from the controller (52)
IX (ID code) is supplied to the recording processing circuit (51). In this case, this index signal CDIX is
As shown in the third diagram (A-C and E of the same figure are A-C of the same figure)
, E), blocks BLKI to BLK6 are the same as before, but the spare block BAUX has an index end code IENC of a specific bit pattern.
It is said that

Then, in the forming circuit (66), in the 1st and 5th horizontal period when the heads (34^) and (34B) are scanning the section (242) with reference to the rising point of the pulse Ps (or the changing point of the signal Sw). A pulse Pi of "H" level is formed, and this pulse Pi is supplied to the processing circuit (51), and as shown in H in the figure, the preamble signal and the index signal CDIX enter the pi phase during the period of Pi - "11". It is converted into a mark signal St and taken out.

Then, during the field period Ta, this signal St is transmitted from the OR circuit (42) to the switch circuit (32) to the amplifier (33).
B) → is supplied to the head (34B) through the signal line of the contact R of the switch circuit (6'7B), and during the field period Tb, the OR circuit (42) - switch circuit (32) →
The signal is supplied to the head (34A) through the signal line of contact R of the amplifier (33A) and switch circuit (67A). Therefore, in track (2), the signal Sp is recorded in the PCM audio data section (23), and then the signal Sp is recorded in the section (24).
2), the signal Si, that is, the preamble signal and index signal CDIX is recorded.

Therefore, each signal is recorded on track (2) in the format shown in FIG.

On the other hand, during playback, the heads (34A) and (34
The signals Sp, Sx and Sf are alternately reproduced from the track (2) by the switch circuit (6
It is supplied to the switch circuit (36) through the reproduction side contacts P of 7A) and (67B) and further through the reproduction amplifiers (35A) and (35B), and the signal Sw is supplied to the switch circuit (36) as its control signal. ,
The signal Sf is continuously taken out from the switch circuit (36), and the signals Sp and Si are taken out every field period.

Then, the signal Sf from the switch circuit (36) is supplied to the reproduction processing circuit (37) to produce the original color video signal Sc.
and monaural audio signal Sm are extracted.

Further, the signals sp and st from the switch circuit (36) are supplied to the reproduction processing circuit (43), and the pulse Ps
is supplied to the processing circuit (43) as a window signal, and the original stereo audio signal R is extracted from the signal Sp. Further, the ■D code (index signal CDIX) is also taken out from the signal Sp and supplied to the controller (52).

Furthermore, a signal Sp from the switch circuit (36).

Si is supplied to a reproduction processing circuit (53), an index signal CDIX is extracted from the signal Si, and this signal CD
IX is supplied to the controller (52).

However, in this case, when the signal CDIX is taken out from the signal Si, the end code IENC is finally obtained, so for a certain period of time after this code IIENC is obtained, that is, the section where the heads (34A) and (34B) are old. (242) is likely to be scanned, reproduction processing of the signal CDIX is prohibited.

Further, in the controller (52), the processing circuit (52)
3), when the index signal CDIX is obtained from the processing circuit (53), this index signal CDIX is used; when the index signal CDIX is not obtained from the processing circuit (53), the index signal
(when DIX is not recorded), the index signal CDIx (ID code) from the processing circuit (43) is used to perform processing such as cueing, absolute position, cut number, etc.

Thus, according to the present invention, the postamble section (2
Since the index signal CDIX is recorded in a part (242) of 4), the necessary ID code can be obtained immediately during search playback, but in this case, especially according to the present invention, the index signal Since an end code IHNC is added at the end, during playback, the index signal C is used for a certain period from this end code IENC.
By prohibiting the reproduction process of DIχ, even if an old index signal section (242) remains following a new index signal section (242), as shown in Figure 10, this old index signal section (242) is A correct index signal CDIX can be obtained without making the index signal CDIX valid.

FIG. 4 shows an example of the processing circuits (51) and (53), in which the portion indicated by the chain line is formed into a single-chip IC.

That is, in the same figure, (45) indicates a clock forming circuit, and the clock formed by this is transmitted to the processing circuit (45).
1) and (43) as well as processing circuits (51) and (53). Also, (55
) indicates a control signal forming circuit, in which various control signals are formed at predetermined timings based on the pulse Pi, and these control signals and the forming circuit (
45) is supplied to each circuit.

Then, during recording, during a period when the head (34^), <34B) is not scanning the section (242), the controller (52) outputs an index signal CDIX without an end code IENC, and this index signal CD
IX connects the buffer RA through the switch circuit (72).
At the same time, the address signal is supplied to R from the controller (73) through the switch circuit (74).
AM (71) and therefore RAM (71)
The index signal CDIX to be recorded is stored in .

Then, when the heads (34A) and (34B) reach the starting end of the section (242), the pulse Pi
becomes 1H', a preamble signal is output from the preamble forming circuit (81) over a 0.5 horizontal period, and this preamble signal is supplied to the encoder (85) and encoded into the pi-phase mark signal St.
This signal St is output to the OR circuit (42).

Next, the head (34^) and (34B) are the section (242
), the address forming circuit (
73) to the RAM (71) through the switch circuit (74).
) is supplied with the address signal and the index signal CDI
X is read out, this index signal CDIX is supplied to the register (83) through the switch circuit (72) and converted from a parallel signal to a serial signal, and this serialized index signal CDIX is sent to the CRCC forming circuit (84). A CRC code is added to the index signal CDIX to which the CRC code is added.
is supplied to an encoder (85) and converted into a signal Si, and this signal St is output to an OR circuit (42).

Furthermore, an index end code IENC with a predetermined bit arrangement is formed in an end code forming circuit (82), and this code IBNC is supplied to an encoder (84) and encoded into a pi-phase mark signal Si. is output to.

Therefore, the index signal CDIX having the preamble signal and the encode IENC is recorded in the section (242).

On the other hand, during playback, the signal S from the switch circuit (36)
p, St are supplied to a decoder (85) to decode the index signal CDIX, and this index signal C
DIX is supplied to the CRCC check circuit (87) and C
Error checking of the index signal CDIX is performed using the RC code.

Then, the index signal CDIX from the check circuit (87) is supplied to the register (88) and converted from a serial signal to a parallel signal, and this parallelized index signal CDIX is sent to the RAM (71) through the switch circuit (72). written. In addition, at this time, the RA is connected from the formation circuit (73) through the switch circuit (74).
The address signal is supplied to M (71).

Also, at this time, the output of the decoder (86) is output from the detection circuit (
91) and the end code rENc is detected,
The detection output is supplied to the check circuit (87) through the timer circuit (92) to check the end code I as described above.
The processing of the check circuit (87) is prohibited for several horizontal periods after ENC is detected, that is, during a period when the head (34^), (34B) may be scanning the old section (242). .

Therefore, only the index signal CDIχ of the new section (242) is taken out from the check circuit (87).

When writing of the index signal is completed, an address signal is supplied from the controller (52) to the RAM (71) through the switch circuit (74), and the index signal CDIX is read out. The index signal is taken into the controller (52) through the circuit (72), and thereafter, processing corresponding to the index signal, such as cueing, is performed.

G2 Other Embodiments In the above description, the end code IHNC of a specific focus pattern is added to the index signal CDIX, but as shown in FIG. 5C (FIG. 5A).

I3. C, D are gA3 Figure I3. Same as C and E)
This is a case where an index start code ISTC of a specific focus pattern is added to the beginning of the index signal CDIX.

Therefore, in this case, during playback, this start l5
Once TC is detected, block BLKI~
During the BLK6 period, the processing circuit (53) is allowed to process, and the following several horizontal periods, namely, the head (34A),
(3411) may be scanning the old section (292), the processing of the processing circuit (53) is prohibited.

FIG. 6 shows another example of an index signal, namely:
Format A is the above-mentioned signal format, and for format B, the section (291) is no signal (no recording), and the section (292) is 0 from its tip.
．． A preamble signal of all "1" is recorded in the 5H section, and a cue index signal CU is recorded in the remaining IH section.
All 60'' are recorded as IX, and in the case of format C, all 1's are recorded as cue index signal CUIX in format A.

Furthermore, in the case of formats D and E, the interval (2
91) is made equal to the interval (292) of formats B and C, and the interval (292) is made equal to the interval (292) of format A.

In the case of formant A-C, as mentioned above, the start code I STC or end code I is added to the beginning or end of the index signal CDIX or CUTχ.
ENC is added, and in the case of formats D and H, a start code 15TC or an end code I[NC is added to the beginning of the index signal CUIX or the end of the index signal CDIX.

The above formants are used in any one of types (1) to (2) depending on the grade of the VTR.

That is, as shown in FIG. 7A, it is assumed that the recording on tape (1) is divided into a plurality of cuts (the term "cut" here also includes concepts such as chapters), then: In the case of type I, the index signal is recorded in format A regardless of each cut, as shown in FIG. Therefore, this type I is a high-end model (
Information such as the absolute position can be obtained by checking the ID codes IDO to ID5 of the index signal CDIX in a high-end model.

Furthermore, in the case of type (2), as shown in FIG. 2C, the index signal is recorded in format B for, for example, 10 seconds from the beginning of each caputo, and the index signal is recorded in format C for the remaining period. Therefore, this type ■ is "0" and "
This can be used to locate the beginning of each cut by determining 1''.

In the case of type ■, as shown in the same figure, index signals are recorded alternately for each track (2) in formats A and B for, for example, 10 seconds from the beginning of each cut, and for the remaining period, index signals are recorded in format A. and C to track (2
), index signals are recorded alternately. Therefore, according to this type (■), lower models can locate the beginning of each cut by determining O"sl" of the index signal CUIX, and higher models check the ID code tDo-ID5 of the index signal CDIX. This allows information such as absolute position to be obtained. In other words, it is compatible with lower models and higher 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 0''.

By determining “1”, you can locate the beginning of each cut.
For higher-end models, ID code I of index signal CDIX
By checking DONID5, information such as the absolute address can be obtained, and it is also compatible with lower and higher model models.

Note that the above is for 8mm video, but
It can also be applied to a multi-track 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, it is also possible to record and reproduce a postamble signal of PCM audio data, other index signals, etc. in section (241) in format A-C. Also, instead of prohibiting the processing of old index signals by the detection circuit (91) and timer (92),
The old index signal can be ignored in the controller (52), and the start code I5TC or the end code IENC can also be generated by the controller (52). Furthermore, the interval (21), (
22) and (29) can also be used when recording and reproducing index signals.

Effects of the Invention According to this invention, since the index signal CI) is recorded in part (242) of the postamble section (24), the necessary ID code can be obtained immediately during search playback. However, in this case, especially according to this invention,
End code I at the end of the index signal CDIX
Since ENC is added, when playing, this end code II! Index signal CDI for a certain period from NC
By prohibiting the reproduction process of A correct index signal CDIX can be obtained without making the index signal CDIX valid.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of an example of the present invention, and FIGS. 2 to 10 are diagrams for explaining the same. (31), (41), and (51) are recording processing circuits; (37); (43) and (53) are reproduction processing circuits.

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 magnetic recording device that sequentially records on a tape as diagonal magnetic tracks, an index section is provided at a position on the magnetic track where the information signal is not recorded, and in this index section, information related to the information signal is provided. A magnetic recording device for information signals, which records an index signal obtained by adding a start code or an end code of a specific bit pattern to the start or end of the index signal.