JP2522262B2 - Information signal magnetic recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The following description will be given.

A Industrial Field B Outline of the Invention C Conventional Technology D Problems to be Solved by the Invention E Means for Solving Problems (FIG. 1) F Action G Example G ₁ First Example ( 1 to 5) G ₂ Other Embodiments H Effect of Invention A Field of Industrial Application This invention relates to a VTR and the like.

B Outline of the Invention The present invention is applied to a VTR of a helical scan type such as an 8 mm video, by recording or reproducing an index signal having a predetermined content with respect to an overlapping portion at the end of an information track, thereby performing a VTR. It is an expansion of the function as.

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

That is, in the figure, (1) is a magnetic tape,
(2) shows a magnetic track, and this track (2)
The two rotating magnetic heads having an angular interval of 180 ° are formed or scanned at an angle to the tape (1) and at a length corresponding to a rotation angle of 221 ° of the rotating head.

Then, from the tip of the track (2),
The section (2S) corresponding to the rotation angle of ° is for audio signals,
The section (2V) corresponding to the remaining 185 ° rotation angle is used for video signals.

Then, the audio track (2S) is divided into sections (21) to (25) in the distribution shown in the figure, the section (21) is a scanning start section (head plunge section) of the rotary head, and the section (22) is a clock. The preamble section of the run-in recorded and played, (2
3) is the audio data section in which the PCM audio signal is recorded and played,
(24) is a postamble section for back margin during after recording, and section (25) is a guard section for tracks (2S) and (2V).

Also, in this case, the PCM audio signal of the section (23) is the time-based compression and the PC of the stereo audio signal for one field period.
It is converted into an M signal and has an error correction code and an ID code. Then, the signals in the intervals (22) to (24) are 2.9 MHz when the value is “0”, and 5. when the value is “1”.
It is recorded after being converted to a bi-phase mark signal of 8MHz.

Further, the video track (2V) is divided into a section (28) corresponding to the rotation angle of 180 ° following the guard section (25) and a section (29) corresponding to the remaining rotation angle of 5 °, and the section ( 2
8) shows one field of the signal in which the FM signal modulated by the luminance signal, the carrier color signal converted by the low frequency band, the FM signal modulated by the monaural audio signal, and the pilot signal are frequency-multiplexed. Recorded and played back. In addition, section (2
9) is a scanning end section (head separation section) of the rotary head.

(Reference: “Journal of the Television Society”, Vol. 29, No. 4, etc.) D Problems to be Solved by the Invention According to the above-mentioned format, the audio data section (23)
Since the ID code is recorded at the same time as the voice signal,
Various data such as recording date, absolute position, program number, etc. can be recorded as an ID code, which is extremely convenient for cueing and editing during playback.

However, in 8 mm video, the audio signal is PCM.
The function of recording on the track (2S) in the signal state is an option. And, the track (2S) is not recorded and played,
In the case of an 8 mm video that cannot be reproduced, its track format is the section (22) as shown by the broken line in Fig. 7.
There will be no ~ (25).

Therefore, in the 8 mm video without this optional function, since the ID code cannot be recorded and reproduced, it is not possible to cue at the time of reproduction, and further functions cannot be realized and it is inconvenient for editing and saving. Met.

The present invention is intended to solve such a problem.

E Means for Solving the Problems In the magnetic recording apparatus for information signals according to the present invention, the magnetic tape is slanted at a constant speed over a predetermined angular range with respect to the rotating peripheral surface of the rotating magnetic head, and the rotating magnetic head is rotated. In a helical scan type magnetic recording apparatus in which an information signal is supplied to a magnetic tape for a predetermined period and is sequentially recorded on a magnetic tape as diagonal magnetic tracks, the two values given for each cut of the information signal are different. A first index signal recording means for recording a bi-phase mark signal as a frequency and a second index signal recording means for recording an absolute address on the magnetic tape are provided, and the scanning of the rotary magnetic head following the magnetic track is completed. When the rotary magnetic head is scanning the section, the first index signal recording means and / or the second index signal recording means. The recording means, a plurality of formats (A to which different scanning end section
According to E), the first index signal (CUIX) and / or the second index signal (CDIX) is recorded.

F action The cue signal for cueing and the absolute position information are reproduced.

G Embodiment G ₁ First Embodiment First, the recording format of the index signal will be described. As mentioned above, the section (2
9) has a length of about 7.3H, and since the rotary head normally scans in a section of several H from the tip thereof, as shown in FIG. 4A, it is 1.5 from the tip of the section (29). Section of H (291)
And the subsequent section of 1.5H (292) are used as the index signal section.

Then, as shown in FIG. 9B, in the case of the format A, the section (291) is set as no signal (no recording), and the section (2
92), the preamble of all "1" is recorded in the section of 0.5H from the tip, and all "0" is recorded as the cue index signal CUIX in the section of the remaining 1H, and the format B is used.
In this case, all "1" are recorded as the cue index signal CUIX in the format A. Further, in the case of the format C, the coding index signal CDIX (details will be described later) is recorded instead of the cue index signal CUIX in the formats A and B.

Further, in the case of formats D and E, the section (291) is made equal to the section (292) of formats A and B, and the section (292) is made equal to the section (292) of format C.

The coding index signal CDIX is shown in the block BLK1 to BLK6 as shown in FIG.
And its end code BEND, and as shown in FIG. 7D, the blocks BLK1 to BLK6 have a 3-bit mark code, an 8-bit ID code ID0 to ID4, and an 8-bit CRC for them. Split into code.

In this case, the ID codes ID0 to ID4 are the same as the ID codes ID0 to ID4 that are recorded at the same time when the PCM audio signal is recorded in the section (23), and are recorded on the tape (1). Is a signal such as the absolute position of, the cut number of each cut of the recorded contents, the date and time when the recording was made, and the hour, minute, and second.

The signals in these sections (291) and (292) are
Similar to the signal on the audio track (2S), it is recorded after being converted into a bi-phase mark signal of 2.9 MHz at "0" and 5.8 MHz at "1".

The above format is used in any one of types I to III corresponding to the grade of VTR.

That is, as shown in FIG. 5A, it is assumed that the recording on the tape (1) is divided into a plurality of cuts (the term "cut" here includes the concept of chapters in a video disc). . Then, in the case of type I,
As shown in FIG. 9B, the index signal is recorded in the format A for 10 seconds from the beginning of each cut, and the index signal is recorded in the format B for the remaining period. Therefore, this type I can be used when a cue is made for each cut by discriminating between "0" and "1" in a lower model (low-cost model).

In the case of type II, as shown in FIG. 6C, the index signal is alternately recorded for each track (2) in the formats A and C for 10 seconds from the beginning of each cut, and the remaining period is the format. Index signals are recorded alternately for each track (2) in B and C. Therefore, according to this type II, in the lower model, the cue of each cut can be found by discriminating between "0" and "1" of the index signal CUIX, and in the higher model, the ID code ID0 to ID5 of the index signal CDIX. Information such as absolute address can be obtained by checking. That is,
Compatible with lower and upper models.

Further, in the case of type III, as shown in D of FIG.
The index signal is recorded in and the index signal is recorded in the format E during the remaining period. Therefore, according to this type III, in the lower model, it is possible to find the beginning of each cut by discriminating between "0" and "1" of the index signal CUIX, and in the higher model, the index signal CDIX
Information such as absolute address can be obtained by checking the ID codes ID0 to ID5 of, and it is also compatible with the lower and upper models.

Next, an example of an 8 mm video that realizes the index signal and the recording format described above will be described.

In FIG. 1, (34A) and (34B) are rotary magnetic heads, and these heads (34A) and (34B) have an angular interval of 180 ° with each other and a motor (52) through a rotary shaft (51). The magnetic tape (1) is rotated at a frame frequency, and the magnetic tape (1) is made to run obliquely at a constant speed over an angular range of about 180 ° with respect to the peripheral surface of rotation. In this case, although not shown, the heads (34A), (3
The rotation phase of 4B) is servo-controlled so as to be synchronized with the recorded video signal at the time of recording and to properly scan the track (2) at the time of reproduction.

Therefore, as shown in FIGS. 2A and 7, in every other field period Ta, the head (34A) scans the section (28) of the track (2) and the number before and after the period Ta. The head (34A) scans the sections (21) and (29) before and after the section (28) in the horizontal period, and the head (34B) tracks the track (2) in the remaining every other field period Tb.
The section (28) of the head (34B) scans the section (28) before and after the section (28) in several horizontal periods before and after the period Tb.
1) and (29) will be scanned.

Then, at the time of recording, the color video signal Sc and the monaural audio signal Ss are supplied to the recording / reproducing processing circuit (31) and the above-mentioned FM luminance signal, the low-frequency-converted carrier color signal, and the FM signal.
The frequency-multiplexed signal Sf of the voice signal and the pilot signal is continuously extracted as shown in FIG.
Is supplied to the switch circuit (32).

Further, for example, a pulse generation means (53) is provided on the rotating shaft (51), and a pulse Pg of a frame period indicating a rotation phase of the heads (34A) and (34B) for each rotation of the heads (34A) and (34B). Is taken out, this pulse Pg is shaped amplifier (54)
A rectangular wave signal Sw which is supplied to the signal forming circuit (55) through each of the periods and is inverted every period Ta and Tb is taken out, and this signal Sw is supplied to the switch circuit (32) as its control signal. The switch circuit (32) is switched between the state shown in the figure and the state opposite to the figure during the periods Ta and Tb. Therefore, the signals Sf and Sf are alternately extracted from the switch circuit (32) for each of the periods Ta and Tb as shown in FIG.

Then, the signals Sf and Sf are recorded amplifiers (33A), (33
B) and further supplied to the heads (34A), (34B) through the recording side contacts R of the switch circuits (61A), (61B). Therefore, as shown in FIG. 7, on the tape (1), the signals Sf and Sf are supplied to the video signal section (28) at intervals Ta and Tb.
(28) are sequentially recorded.

Further, the signal Sw is supplied to the forming circuit (43), and the signal Sw is shown in FIG.
As shown by E and F, a pulse Pi that becomes "H" level for 1.5 horizontal periods from the end of the periods Ta and Tb and a pulse Pj that becomes "H" level in the following 1.5 horizontal periods are formed. To Pj are supplied to the conversion circuit (42) as timing signals.

The conversion circuit (42), which will be described in detail later, sends a cue signal or ID code for cueing corresponding to the formats A to F and a preamble during a period of Pi = "H" to Pj = "H". It is to be converted into the index signal CUIX or CDIX which it has. The converted cue signal or ID
The code is supplied from a controller (microcomputer) (41) that manages these.

Therefore, from the conversion circuit (62), the format A to
The index signal CUIX corresponding to F during the period of Pi = “H” to Pj = “H”, that is, the period in which the head (34A) or (34B) scans the section (291) to (292).
Or CDIX is taken out.

Then, this index signal is supplied to the encoder (43) and encoded into the bi-phase mark signal Sb, and this signal Sb is supplied to the switch circuit (32). Therefore, in the case of types I and II, the signals Sf and Sf of the periods Ta and Tb and the signals Sb and Sb after 1.5 horizontal periods are taken out from the switch circuit (32) as shown in FIG. It is supplied to the heads (34A) and (34B), and in the case of type III,
As shown in FIG. 6H, the signal Sb is taken out following the signals Sf and Sf in the periods Ta and Tb and supplied to the heads (34A) and (34B).

Therefore, in the section (28) of the track (2), the video signal
Sf is recorded and the following sections (291) to (29
The index signals CUIX or CUIX are recorded in 2).

On the other hand, at the time of reproduction, the signals Sf and Sb from the track (2) are changed by the heads (34A) and (34B) to G or H in FIG.
As shown in, the reproduced signals Sf and Sb are alternately reproduced every field period Ta and Tb.
A) and (61B) are supplied to the switch circuit (36) through the reproduction side contacts P 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 from the switch circuit (36)
Are continuously extracted, and the signal Sb is extracted for each field period.

Then, when the signal Sf from the switch circuit (36) is supplied to the processing circuit (31), the original color video signal Sc and the monaural audio signal Ss are taken out.

Also, the signal Sb from the switch circuit (36) is supplied to the decoder (44) to decode the index signals CUIX or CDIX, and this signal is supplied to the conversion circuit (45) for error correction. Is converted into a cue signal 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, the index signal can be recorded or reproduced even in the 8 mm video in which the PCM audio signal is not recorded or reproduced, and the cueing and editing can be conveniently performed.

In that case, in particular, according to the present invention, the index signal is recorded / reproduced in the vicinity of the tip (291), (292) of the head scan end section (29) following the video track section (28). Section (291), (292) even after-recording PCM audio signal with 8mm video
Is not affected by it, and therefore the video signal Sc and audio signal Ss recorded in the video signal section (28) are
The data such as the recording time is not erased or destroyed, and the data is retained in correspondence with the recorded content.
Also, the video signal Sc and the audio signal Ss are compatible with other 8 mm video.

Furthermore, since the scan end section (29) is formed in any 8 mm video, the mechanism can be the same as before, and the circuits (41) to (45) can also record and reproduce PCM audio signals. The IC used for video can be used as it is, and therefore the index signal can be recorded and reproduced at low cost. Further, for the same reason, the index signal can be recorded even by a compact and lightweight machine dedicated to recording.

Also, during variable speed reproduction, the heads (34A) and (34B) will cross the track (2) diagonally.
Since 1) and (292) are as short as 1.5 horizontal sections, for example, the heads (34A) and (34B) are almost parallel to the sections (291) and (292) even at 30x speed search playback, or they track almost correctly. Then, the index signal can be surely reproduced.

FIG. 3 shows an example of the conversion circuits (42) and (45), in which the portions indicated by chain lines are integrated into one chip IC together with the circuits (43) and (44).

That is, in the figure, (61) indicates a clock forming circuit, and (62) indicates a control signal forming circuit. In this forming circuit (62), various control signals are formed at a predetermined timing with reference to the pulses Pi to Pj. The control signal and the clock of the forming circuit (61) are supplied to the respective circuits.

Then, at the time of recording, the index signals CUIX to CDIX are output from the controller (41) while the heads (34A) and (34B) are not scanning the sections (291) to (292), and the index signals are output to the switch circuit. It is supplied to the buffer RAM (64) through (63) and
The address signal is supplied from the controller (41) through the switch circuit (65) to the RAM (64), and thus the RAM
The index signal to be recorded is stored in (64).

Then, when the heads (34A) and (34B) reach the start ends of the sections (291) to (292), at this time, the pulses Pi to Pj become "H", so that the preamble forming circuit (71) over 0.5 horizontal period. Outputs a preamble signal from the encoder, supplies the preamble signal to the encoder (43), encodes the biphase mark signal Sb, and outputs the signal Sb to the switch circuit (32).

Then, when the heads (34A) and (34B) pass the 0.5 horizontal section of the sections (291) to (292), an address signal is supplied from the address forming circuit (66) to the RAM (64) through the switch circuit (65). Index signal CUIX or
The CDIX is read, this index signal is supplied to the register (72) through the switch circuit (63) and is converted from a parallel signal to a serial signal, and this serialized index signal is supplied to the CRCC formation circuit (73). hand
The CRC code is added, the index signal added with the CRC code is supplied to the encoder (43) and converted into the signal Sb, and the signal Sb is output to the switch circuit (32).

Therefore, the preamble and index signals are recorded in the sections (291) to (292) corresponding to the types I to III.

On the other hand, during reproduction, the signal Sb from the switch circuit (36)
Is supplied to the decoder (44) to decode the index signal, and the index signal is supplied to the CRCC check circuit (74) to check the error of the index signal by the CRC code. In this case, the head (34
When A) and (34B) are scanning a section other than the sections (291) to (292), a signal other than the signal Sb is supplied to the decoder (44), but it is correct from the check circuit (74). Since only the index signal is taken out, there is no need for timing by the pulses Pi or Pj.

Then, the index signal from the check circuit (74) is supplied to the register (75) to convert the serial signal into a parallel signal, and the parallelized index signal is written in the RAM (64) through the switch circuit (63). . At this time, the address signal is supplied from the forming circuit (66) to the RAM (64) through the switch circuit (65).

Then, when the writing of the index signal is completed,
RA from the controller (41) through the switch circuit (65)
An address signal is supplied to M (64) to read an index signal, the read index signal is taken into the controller (41) through the switch circuit (63), and thereafter, processing corresponding to the index signal, For example, cueing is performed.

G ₂ Other Embodiments In the above, the case of 8 mm video is used, but the present invention can be applied to any helical scan type VTR such as beta format VTR. In addition, the video signal section (28) is divided into multiple sections, and the PC
It can also be applied to a multi-track machine that records or reproduces information signals such as M audio signals and still image video signals. Furthermore, in formats A to C, the section (29
Other index signals can be recorded and reproduced in 1).

H Effect of the Invention According to the present invention, the index signal can be recorded or reproduced even in the 8 mm video in which the PCM audio signal is not recorded or reproduced, and the cueing and editing can be conveniently performed.

In that case, in particular, according to the present invention, the index signal is recorded / reproduced in the vicinity of the tip (291), (292) of the head scan end section (29) following the video track section (28). Section (291), (292) even after-recording PCM audio signal with 8mm video
Is not affected by it, and therefore the video signal Sc and audio signal Ss recorded in the video signal section (28) are
The data such as the recording time is not erased or destroyed, and the data is retained in correspondence with the recorded content.
Also, the video signal Sc and the audio signal Ss are compatible with other 8 mm video.

That is, the first index signal recording device and / or the second index signal recording device causes the first index signal (CUIX) and / or the second index signal ( By recording CDIX), it is possible to easily find the beginning of each cut by discriminating between "0" and "1" based on the first index signal (CUIX) in the lower model. Further, in the upper model, information on the absolute address can be obtained based on the second index signal (CDIX), and can be commonly used for both the lower model and the upper model.

Furthermore, since the scan end section (29) is formed in any 8 mm video, the mechanism can be the same as before, and the circuits (41) to (45) can also record and reproduce PCM audio signals. The IC used for video can be used as it is, and therefore the index signal can be recorded and reproduced at low cost. Further, for the same reason, the index signal can be recorded even by a compact and lightweight machine dedicated to recording.

Also, during variable speed reproduction, the heads (34A) and (34B) will cross the track (2) diagonally.
Since 1) and (292) are as short as 1.5 horizontal sections, the heads (34A) and (34B) are almost parallel to the sections (291) and (292), or tracking is almost correct, even during search playback at 30 times speed. Then, the index signal can be surely reproduced.

[Brief description of drawings]

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 / reproducing processing circuit, and (42) and (45) are conversion circuits.

Claims (1)

(57) [Claims] 1. A magnetic tape is slanted at a constant speed over a predetermined angular range with respect to the circumferential surface of a rotary magnetic head, and an information signal is supplied to the rotary magnetic head for a predetermined period of time. In a helical scan type magnetic recording apparatus that is sequentially recorded as oblique magnetic tracks, a bi-phase mark signal having different frequencies with respect to two values given for each cut of the information signal is recorded. Index signal recording means and second index signal recording means for recording an absolute address on the magnetic tape, and the rotary magnetic head scans a scanning end section of the rotary magnetic head following the magnetic track. In this case, by the first index signal recording means and / or the second index signal recording means, The magnetic recording apparatus of the information signal, characterized in that the plurality of different formats in serial scan end section were to record the first index signal and or the second index signal.