JPH0799627A - Time lapse magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To correctly and easily obtain a reproduced picture of each channel independently of intermittent recording and normal-speed recording even at the time of search reproducing when recorded contents are quickly seen with respect to the time lapse VTR of multichannel recording. CONSTITUTION:Recorded picture information (channel number) is generated and is added 44 to one continuous video signal, which is generated by successive switching of video camera outputs by a video switching means 4; and at the time of search reproducing, the period of write to a picture memory 49 is controlled in accordance with recorded picture information and the reproducing head signal level, and next, successive read out the video signal of a picture memory means where only a specific channel is stored is controlled by a read control means 57. Rotation of magnetic heads 12 to 15 and tape running are so controlled that the reproduced signal of the part of a prescribed position where recorded picture information is added is always obtained in a prescribed level or higher. The number of video channels to be recorded is increased or reduced in accordance with the number of channels of an input video signal and the search speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a time-lapse magnetic recording / reproducing apparatus (hereinafter abbreviated as time-lapse VTR) which is used for monitoring and crime prevention, for recording / reproducing by intermittently skipping video signals. .

[0002]

2. Description of the Related Art Recently, in order to monitor and record various places at the same time in factories, construction sites, stores, etc., video signals from a plurality of video cameras are sequentially switched to intermittently record frames on a video tape. For example, a time-lapse VT that can record a long time of 720 hours on one tape.
R is widely used. As a result, when an abnormality occurs, the recorded video signal can be reproduced to obtain valuable information.

For example, in Japanese Patent Laid-Open No. 62-295581, the outputs of a plurality of video cameras are sequentially recorded on the same magnetic tape for each field (or frame), and only the desired video camera output from the magnetic tape is reproduced at the time of reproduction. 1
A time-lapse VTR is shown in which the contents of a field (or frame) can be taken out and the recorded contents can be confirmed correctly.

Hereinafter, referring to the drawings, as an example, VH
A configuration of a conventional time-lapse VTR using an S type video cassette tape will be described.

FIG. 22 shows an example of the configuration of a monitoring system using a conventional time-lapse VTR. In FIG. 22, 1 is a time-lapse VTR, 2 is a switcher, 3
a to 3n are video cameras, and video cameras 3a to 3n
The video signals from (each A, B, C to N ch) are sequentially switched by the video switching circuit 4 of the switcher 2 with the field or frame as the minimum unit, and then the recorded video information adding means 5 changes the video channel number or the like. The recorded video information is added to a predetermined position (for example, a part of the vertical blanking period) for each video field and supplied to the time-lapse VTR 1. Note that FIG. 22 shows an example in which the switcher 2 is separated into another device, but the same applies to the case where the switcher 2 is built in the time-lapse VTR 1. In time-lapse VTR1,
The chroma signal of the input video signal is converted to the low frequency band by the color low frequency conversion circuit 7, while the luminance signal is converted to the FM modulation circuit 8.
After being frequency-modulated by, the outputs of both circuits 7 and 8 are added, and then the magnetic heads H1 + (12), H2- (13) and H3- (1 mounted on the cylinder 11 via the recording amplifier 10 are added.
4) and H4 + (15) are paired, and the video of each channel is sequentially recorded without frames on the diagonal track on the magnetic tape 16. In this case, an intermittent recording / reproducing mode in which the tape is intermittently run (for example, a tape in a normal speed mode in which the tape is continuously run at a normal speed for recording / reproducing (for example, 33.33 mm / sec in the standard mode of the VHS system)) It is possible to record for a long time by recording when stopped. The magnetic head H
1+ (12), H4 + (15) and magnetic head H2- (13),
H3- (14) are azimuth angles α and β (normally α = + θ, β = -θ) that are different from each other, and are recorded alternately at different azimuth angles, which significantly reduces interference from adjacent tracks during reproduction. ing.

During reproduction, the magnetic head H1 + (1
2), H2- (13), H3- (14), and H4 + (15) reproduced signals are amplified by preamplifiers 16, 17, 18, 19 and then pass through switch circuits 20, 21, 22. , The color high frequency conversion circuit 23 and the FM demodulation circuit 24 respectively restore the original band into the chroma signal and the luminance signal, which are further added by the adding circuit 25 to obtain a reproduced video signal. In the syscon means 27, the servo circuit 30 for controlling the cylinder 11, the control head 28, and the capstan motor 29 is operated in accordance with the operation mode input by the user through the mode setting input means 26.
Controls the operating state of the time-lapse VTR1. Further, the syscon means 27 operates the switching circuit 31 so that one of the outputs of the switch circuits 20 and 21 becomes the output of the switch circuit 22 in the normal speed of the tape or the reproduction mode of the intermittent running, and the tape is run at a speed faster than the normal speed. In the search reproduction mode, the level comparison and detection circuit 32 compares and detects the outputs of the switch circuits 20 and 21, and the larger one is used as the output of the switch circuit 22.

The switcher 2 includes an A / D means 33 for writing and reading a video signal, an image memory 34, and a D / A.
Means 35 and memory control means 36 for controlling them are provided. First, the video channel number recorded by the recorded video information detecting means 37 is detected from the reproduced video signal from the time lapse VTR 1, and this video channel number is also detected. In addition, by writing only the reproduction image of the desired channel set by the reproduction channel setting means 38 into the image memory and reading it, only the reproduction image of the desired channel can be read.
Reproduction is performed on the V monitor 39.

Here, in the case of intermittent reproduction of the intermittently recorded tape, as shown in FIG.
Based on the SW30 signal 40 indicating the period in which 15 is in contact with the tape, a substantially flat and good head reproduction signal can be obtained as shown in FIG. 23 (e) or (f). Also, when the intermittently recorded tape is played back at a normal speed for a short time, as shown in FIG. 24, the inclination of the recording track and the reproduction trace is different by one track, so that the tape slightly looks like an abacus ball, but it is above the required level. A head reproduction signal is obtained. Therefore, the channel number added to the predetermined position can be accurately detected, the video signal of each channel is reproduced for each track, and both A, B, and C selected and set via the switcher 2 are set. A reproduced image of ~ Nch is satisfactorily obtained.

[0009]

However, in the above-mentioned conventional time-lapse VTR, the reproduction trace locus of the magnetic head is, for example, as shown in FIG. As shown in the example of 4ch recording and 5x speed search, it will span a plurality of tracks. In this case, the outputs of the switch circuits 20 and 21 are like abacus balls as shown in FIGS. 26 (f) and 26 (g), the level detection circuit 32 selects the higher level, and the output of the switch circuit 22 is FIG. 26
The waveform becomes as shown in (h), and as shown in FIG. 26 (i), the playback channels are switched to A, B, C, and Dch in response to the track switching during the playback 1 field period. Will be partially present. Therefore, when the reproduction signal at the above-mentioned predetermined position to which the channel number is added is near the track switching point,
The channel number added to the above-mentioned predetermined position cannot be detected accurately, and the reproduction channel will be wrong. Moreover, even if the recording channel number can be accurately detected, a plurality of channels other than the channel whose number is detected are partially present in each playback field as shown in FIG. Since the writing and reading to and from are performed for each field, as illustrated in FIG. 27, in the field T1, for example, the reproduction signals of B1, C1, D1, and B2 are erroneously written in the image memory with respect to the detection number Ach. As a result, each A, B, C, Dch is multiplexed and reproduced, and a reproduced image of only a predetermined channel cannot be obtained, which is very difficult to see.

An object of the present invention is to provide a time-lapse VTR capable of accurately detecting a recording channel number even during search and reproduction, obtaining a good search and reproduction image for each video channel without disturbing the screen, and quickly recognizing and confirming recorded contents. To provide.

[0011]

According to the present invention, in order to solve the above problems, a video switching means for sequentially switching a plurality of input video signals to generate a series of continuous video signals, and the plurality of input video signals. A recorded video information generation / addition means for generating a signal indicating recorded video information such as a channel number corresponding to each channel, and adding the recorded video information signal to a predetermined position of the continuous video signal from the video switching means. Magnetic recording / reproducing means for recording / reproducing an output video signal from the recorded video information generating / adding means on an oblique track on a tape by a rotary magnetic head, and reproducing for generating a reproduced video signal from the output signal from the magnetic head during reproduction. The video signal generating means and the signal for indicating the transition between tracks to be reproduced at the time of search reproduction in which the magnetic head traces across a recording track are generated. Reproduction track switching signal generating means, recorded video information detecting means for detecting recorded video information added at the time of recording from the output of the reproduced video signal generating means, and A / D conversion of the reproduced video signal into an image memory. A writing period to the image memory means for each video channel according to the output from the image memory means for once writing, then D / A converting and reading out, and the recorded video information detecting means and the reproduction track switching signal generating means. Writing period control means for controlling the writing, the writing control means for controlling writing to the image memory means, the reading control means for controlling reading from the image memory means, the rotation of the magnetic head and the running operation of the tape. And a servo means for operating.

Further, the servo means controls the rotation of the magnetic head and the tape running during the search reproduction so that the reproduction signal of the portion at the predetermined position to which the recorded video information signal is added is always obtained at a predetermined level or more. Let

Recording channel control means for controlling the number m of video channels recorded by the magnetic recording / reproducing means to increase or decrease is also provided.

[0014]

Each input video signal is selected by the video switching means with the field or frame as the minimum unit to become one continuous video signal, and then is integrated into the continuous video signal by the recorded video information adding means. Video information such as the total number m of channels of each video signal and each channel number is added to each field for each field, for example, in a vertical blanking period, and then recorded on a magnetic tape by the magnetic head.

During reproduction, the reproduction signal processing circuit means selectively switches the output from the magnetic head to generate a reproduction head signal, and further restores and demodulates the reproduction head signal to the original video signal. On the other hand, the recorded video information detecting means detects the recorded video information added at the time of recording from the reproduced video signal and outputs it to the writing period control means. Further, the writing period control means generates a control signal indicating the writing period to the image memory according to the total number m of detected channels from the recorded video information detecting means and the channel number of each reproduction field. Therefore, the writing control means controls writing to a predetermined portion of the image memory means according to the writing period control signal so that a plurality of channels are continuously reproduced in each reproduction field. The reproduced video signal portion of only a specific desired channel from the video signal is written in the image memory means. Next, the read control means controls the sequential reading of the video signal from the image memory means in which only the specific channel is stored, so that the search reproduction image of only the desired specific channel can be obtained without multiple reproduction of each channel. Therefore, it is very easy to see and you can easily search and confirm the recorded contents at high speed.

Further, during the search reproduction, the servo means automatically controls the tracking so that the reproduction signal of the portion at the predetermined position is always higher than the predetermined level, so that the signal is added to the predetermined position. It is possible to accurately detect the existing channel number, obtain a normal write period control signal without making a mistake in the reproduction channel, and always realize a good search reproduction image of only a specific channel.

In the servo means, the tape running speed is controlled to k.times.v (v: normal tape running speed, positive / negative of k indicates forward / reverse direction search) during search and reproduction, and at the time of search. The tape running speed k is the prime number P
as the product of n,

[0018]

[Equation 1] | k | = P1l1 ・ P2l2 ・ P3l3 ・ ・ ・ ・ ・ Pnln
When (ln is a natural number), the number q of video channels input to the video switching means is

[0019]

## EQU00002 ## When q = a.Pn (a is a natural number), the number of recording channels is m in the recording channel control means.

[0020]

## EQU00003 ## By increasing or decreasing the number of recording video channels so that m.noteq.a.Pn (a is a natural number), a search image can be displayed over the entire screen area of each video channel.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiment.

FIG. 1 is a block diagram of a time-lapse VTR according to the first embodiment of the present invention.

In FIG. 1, 40a, 40b-40n are input video signal terminals, 41 is a sync separation circuit, 42 is switching means for selectively outputting a reference sync signal, and 43 is the presence or absence of video input from the input sync signal. And recording channel control means for detecting the number of input video channels and controlling the video channels to be recorded, and 44 is a recorded video for generating a recorded video information signal such as a video channel number and the total number of channels and adding it to the video output from the video switching circuit 4. Information adding means, 45 is a recording signal conversion circuit for converting a chroma signal of a video signal to a low frequency band while frequency-modulating a luminance signal, 46 is a logic circuit including an exclusive NOR gate, and 47 is a chroma signal to a high frequency band. On the other hand, 48 is a reproduced signal conversion circuit for frequency-demodulating the luminance signal to restore the original band. A digitizing fine luminance signal /
D converter, 49 is an image memory, 50 is a D / A converter for analogizing a video signal, 51 is an encoder circuit for converting the luminance signal and each color difference signal from the D / A converter 50 into a video signal and outputting the video signal. , 52 is a sync separation circuit for separating a sync signal from a reproduced video signal, 53 is a recorded video information detecting means for detecting recorded video information from the reproduced video signal, and 54 is from the recorded video information detecting means 53 and the logic circuit 46. A writing period control circuit that generates a control signal indicating a writing period to the image memory 49 according to an output, 55 is a writing control circuit that controls writing of a video signal to the image memory 49,
Reference numeral 56 is a reference signal generation circuit for generating a reference signal with a stable frequency, and reference numeral 57 is a read control circuit for controlling the read of the video signal from the image memory 49. Reference numeral 58 is an envelope detection circuit for detecting the envelope level of the reproduction signal.
Reference numeral 9 is a recording information period generation means for generating a recording information period signal indicating a predetermined period to which recording information is added, and 60 is a tracking for generating a tracking control signal for controlling scanning of a magnetic head with respect to a recording track on a magnetic tape. It is a control signal generating means. In FIG. 1, the same or equivalent parts as those of the conventional example shown in FIG. 22 are designated by the same reference numerals.

Next, the operation of the embodiment shown in FIG.
A description will be given using 18. FIG. 2 shows an example in which an input video signal of 4 channels is recorded by intermittent tape running,
It shows each signal timing at the time of reproduction by a double speed (k = 5) search. The video signal from each video camera is selected by the video switching circuit 4 for each field or frame and becomes one continuous video signal. on the other hand,
The sync separation circuit 41 separates the sync signal of each input video signal. The recording channel control means 43 determines the presence or absence of each input video signal based on the separated sync signal,
A reference channel is selected from the input video channels in a predetermined order, and the switching circuit 42 controls so that the reference channel sync signal is selectively output to the video switching means 4. Moreover, the recording channel control means 43 controls the video switching means 4 so as to switch the input video signal by adding the reference synchronizing signal to the input video signal in accordance with the number of input video channels and the search traveling speed, or there is an input. The video switching means 4 is controlled so as to reduce the number of video channels recorded with respect to the video channels. Further, in the recording channel control means 43, the recorded video information such as the channel number corresponding to the video channel selected by the video switching means 4 and the total number m of the selected channels is stored in a predetermined position of the video signal for each field. (For example, part of the vertical blanking period),
The recorded video information signal generation / addition means 44 is controlled. Figure 3
Shows an example of a predetermined position where recorded video information is added without damaging the original video part. FIGS. 4 and 5 show a case where a channel number is coded and added as recorded video information at this predetermined position. . Thereafter, the magnetic heads (H1 +, H1) are passed through the recording signal conversion circuit 45 and the recording amplifier 10.
3-group or H2-, H4 + group) is recorded on the magnetic tape.

Here, when the track in which the video signals of the field units of 4 channels are sequentially recorded is reproduced by the 5 × speed search as shown in FIG. 25, first, the switch is made according to the SW30 signal shown in FIG. 2A. The magnetic head output is selected by the circuits 20 and 21, and two sets of reproducing head signals (H1 +, H3- and H2-, H shown in FIGS. 2B and 2C) are selected.
4+ pairs) are generated. Next, the larger level of the two sets of reproducing head signals is detected by the level comparison / detection circuit 32, and during search reproduction, the higher level is always selected from the switch circuit 32 via the switch circuit 31. A reproduction head signal as shown in FIG. 2D is obtained, and subsequently, the reproduction video signal is restored by the reproduction signal conversion circuit 47. Here, the level comparison detection circuit 32
Then, as shown in FIG. 2 (e), both envelope waveforms having the amplitude levels of the above two sets of reproducing head signals are compared to generate a level comparison signal V1 as shown in FIG. 2 (f).
Next, in the logic circuit 46, the level comparison signal and S
From the AND operation with the W30 signal and the AND operation of the inverted signals of these two signals, y shown in FIGS.
o Unamplified signal is obtained, and the O of the signal of FIGS.
The R operation produces a signal as shown in FIG.
As can be seen by comparing with (d), a signal indicating the switching point of the reproduction track is obtained. In this case, in other words, since the azimuth angles α and β are recorded alternately,
2 (i) and its inverted signal, FIG. 2 (j), are signals indicating the azimuth angle of the track being reproduced, and are the first azimuth signal (High is on the α side) and the second azimuth signal, respectively. (High is β side). Further, the recorded video information detecting means 53 detects recorded video information such as the channel number and the total number of channels for each field from the reproduced video signal and supplies it to the writing period control circuit 54. Even if only the channel numbers are recorded as illustrated in FIGS. 4 and 5, the total number of channels can be determined by sequentially detecting the channel numbers at predetermined positions during search reproduction and counting the number of different channel numbers. ,
Alternatively, it is possible to determine the total number of channels by once setting the normal reproduction state and detecting the channel numbers accurately. Further, in the writing period control circuit 54, based on the signal indicating the switching of the reproduction track, the total number m of detection determination channels, and the detection channel number for each reproduction field, FIG. 2 (k), (l), (m) ), (N)
A control signal indicating the writing period of each channel is generated as shown in FIG. That is, according to the total number of detected channels m = 4, the count values obtained when the number of states of High and Low of the first azimuth signal (or the second azimuth signal) are sequentially counted every m = 4 (see FIG. 2). (I)
The control signal indicating the write period of each channel is generated by extracting only the period of (number added to
2 (k), the channel number added in the predetermined period shown in (o) is detected and determined, and the reproduction channel can be determined for each field as shown in FIG. 2 (p). , (L), (m),
As shown in (n), a good write period control signal for each channel can be generated. Therefore, since the writing period control signal of each channel corresponds to each specific channel number added to FIG. 2D, the reproduced video signal of each channel is sent to the image memory 49 via the writing control circuit 55. Can be memorized.

At this time, the TV is read from the image memory 49 by the reference signal generation circuit 56 and the read control circuit 57.
As shown in FIG. 6, the screen searched and reproduced on the monitor has a field T1, which is a half cycle period of the SW30 signal,
The reproduction part of each channel is different for each T2, T3, etc. For example, when viewing Ach, the entire screen can be reproduced in four fields. Of course, it goes without saying that the same applies to other channels. The number of recorded video channels is 2.
It is clear that the same effect can be obtained with 3, 6 and the like.

However, as shown in FIG. 7, when a video signal of 5 channels is input and recorded and reproduced by a search at 5 × speed (k = 5), only a specific part of all channels is reproduced as a video signal. Unable to write to memory and cannot play full screen.

On the other hand, during normal speed recording in which the tape is continuously run at normal speed for recording (for example, 33.33 mm / sec in the standard mode of the VHS system), the tape runs during the recording trace of the magnetic head. The tape recording pattern is tilted by one track with respect to the intermittent recording. Therefore, the reproduction trace locus at the time of search reproduction becomes as shown in FIG. 8 at the time of 5 × speed search, which is different from that at the time of intermittent recording shown in FIG. As an example of this case, FIG. 9 shows each signal timing when a video signal of 4 channels is input and recorded at a normal speed and reproduced by a search at 5 times speed (k = 5), which is shown in FIG. S
Although the video channel immediately after the W30 signal is different, the same operation as in the case of FIG. 2 is performed, and the same effect is obtained as shown in FIG. Also in this case, in the same way, the full screen cannot be reproduced as shown in FIG. 11 during 5-channel recording.

Here, in the first embodiment shown in FIG. 1, the search reproduction images obtained respectively in the case of different recording driving modes such as the total number of recording channels m, the number of search speeds k, and intermittent or normal speed are shown together. , As shown in FIG. From FIG. 12, the tape running multiple speed k at the time of search is defined as the product of the prime numbers Pn,

[0030]

[Equation 1] | k | = P1l1 ・ P2l2 ・ P3l3 ・ ・ ・ ・ ・ Pnln
When (ln is a natural number), the number m of video channels input and recorded in the video switching means is

[0031]

## EQU2 ## When m ≠ aPn (a is a natural number), a good search image can be displayed over the entire screen area in each video channel.

Furthermore, in the present invention, the number of video channels m input and recorded in the video switching means is

[0033]

## EQU3 ## In the case of m = a.Pn (a is a natural number), the recording channel control means 43 is used.
Then, for the number of video channels q input to the video switching means, the reference synchronizing signal from the switching circuit 42 is added to the input video signal, and the video switching means 4 sequentially switches and outputs. Or, by controlling one of the input video channels so as not to output, the number of video channels to be recorded m'is

[0034]

## EQU00004 ## By increasing or decreasing the number of recording video channels with respect to the number of input video channels so as to satisfy m'.noteq.a.Pn (a is a natural number), it is clear from FIG. In both cases, the search image can be displayed over the entire screen area.

In FIGS. 13 and 14, when a video signal of channel 5 is input and recorded and reproduced by a search at 5 × speed (k = 5), a reference sync signal, that is, a video signal of a black screen is added as a sixth channel. FIG. 7 shows a reproduction trace locus and a search reproduction image at the time of recording, and a search reproduction image of the entire screen can be obtained as compared with FIG.

In the first embodiment, the signal indicating the envelope level of the reproduced video signal detected by the envelope detection circuit 58 and the vertical sync signal from the sync separation circuit 52 shown in FIG. 15B are used. The recording information period signal of FIG. 15C generated by the recording information period generating means 59 based on
Is supplied to. The tracking control signal generating means 60 generates a signal indicating the reproduction signal level in the period in which the recorded video information is added based on the both input signals so that the reproduction signal level in the recorded video information period becomes the maximum. The servo means 30 is controlled. That is, the reproduction trace locus 64 is recorded at the recording position 63 of the recorded video information in the recording tracks 61 and 62 whose azimuth angles are α and β, respectively.
For example, in the case shown in FIG. 16 and FIG. 17, the reproduced video signal output does not sufficiently obtain the reproduced signal level during the recorded video information period as shown in FIGS. Will not be detected. On the contrary,
In the present invention, tracking control is performed from the state shown in FIGS. 16 and 17 to the state shown in FIG. 18, and the state shown in FIG.
As shown in, the operation is performed so that the reproduction signal level during the recorded video information period becomes the highest, and at least a predetermined level or higher at which the recorded video information can be normally detected is always obtained.

FIG. 19 shows an embodiment of the essential part of the present invention, in which the same or equivalent parts as in FIG. 1 are designated by the same reference numerals. In FIG. 19, the rotation phase pulse from the rotation phase detector 65 becomes the SW30 signal via the waveform shaping circuit 66, and the phase comparison circuit 67 causes the reference signal generator 68.
Phase comparison with reference signal REF1 from
6 rotates in synchronization with the reference signal REF1. on the other hand,
The reference signal REF2 from the reference signal generator 68 is delayed by the tracking variable circuit 69, and the delayed reference signal DR
The EF2 and the control signal detected by the control head 28 are phase-compared by the phase comparison circuit 70 to control the capstan motor 29. As a result, the capstan motor 29 causes the control signal and the delay reference signal DRE.
The drive is controlled so that the phase is synchronized with F2. Here, by changing the delay time in the tracking variable circuit 69, the phase relationship in the track width direction between the recording tracks 61, 62 and the reproduction trace locus 64 can be changed. Therefore, in the data processing circuit 71, a signal indicating the reproduction signal level during the recorded video information period is received from the tracking control signal generation means 60, and the tracking variable circuit 69 is received.
The delay time Td is controlled variably.

In the data processing circuit 71, first, the level signal of the recorded video information period at the present time (t1) is temporarily stored, and then the delay time Td in the tracking variable circuit 69 is increased by ΔT or And as a result of this,
It is determined whether the level signal in the recorded video information period at this time point (t2) has increased or decreased with respect to the temporarily stored value. If it is increased as a result, the delay time Td is further increased or decreased by ΔT in the same direction. If the value is smaller than the temporarily stored value, the direction of increase / decrease is reversed to decrease or increase the delay time Td by ΔT. At this time, the value of the level signal in the recorded video information period obtained at (t3) and the temporary storage value immediately before (t2) are repeatedly compared again and the same operation is performed. By repeating such a series of operations, it is possible to automatically set and control the reproduction signal level in the period in which the recorded video information is added to a value close to the maximum value.

In the above embodiments, the case where the recording channels are sequentially changed for each recording track has been described. However, as shown in FIG. 20, the same recording channel has a plurality of tracks or a plurality of tracks. Even when the recording channel is changed for each track, as shown in the operation in FIG. 21, the channel numbers are detected in order by the normal reproduction or the search reproduction in order. It goes without saying that a good write period control signal can be obtained by not changing the write period control signal for the same channel, and the same effect as described above can be obtained.

[0040]

As described above, according to the present invention, the recorded video information such as the channel number added to the predetermined position can be automatically and accurately detected, and the normal writing period can be realized without making a mistake in the reproduction channel. A control signal can be obtained, and a search reproduction image in which only a specific channel is always visible over the entire screen area can be realized. In addition, a good search reproduction image can be obtained regardless of the number of input video channels, the search speed, and the recording driving mode such as intermittent or normal speed. Thus, there is an effect that it is very easy to see and the recorded contents can be searched and confirmed easily at high speed.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a first embodiment of the present invention.

FIG. 2 is an operation timing chart at the time of intermittent 4-channel recording / 5-fold speed search in the configuration of the first embodiment of the present invention.

FIG. 3 is a timing diagram for adding a recorded video information code according to the present invention.

FIG. 4 is a diagram showing encoding of the channel number discrimination according to the present invention.

FIG. 5 is a diagram showing a position of a discrimination code signal of a channel number of the present invention.

FIG. 6 is an intermittent 4 channel recording in the first embodiment of the present invention.
Playback screen during 5x speed search.

FIG. 7: Intermittent 5ch recording in the first embodiment of the present invention
Playback screen during 5x speed search.

FIG. 8 is a diagram showing a 5 × speed search in normal speed recording.

FIG. 9 is an operation timing chart at the time of normal speed 4ch recording / search at 5 × speed in the configuration of the first embodiment of the present invention.

FIG. 10 is a playback screen at the time of normal speed 4ch recording / search at 5 × speed in the first embodiment of the present invention.

FIG. 11 is a playback screen during normal speed 5ch recording and 5 × speed search in the first embodiment of the present invention.

FIG. 12 is a diagram showing a state of a search reproduction image in the first embodiment of the present invention.

FIG. 13 is a diagram showing a recording pattern when 5 channels are input and a 5 × speed search in the first embodiment of the present invention.

FIG. 14 is a playback screen during 6ch recording and 5x speed search for 5ch input in the first embodiment of the present invention.

FIG. 15 is a diagram illustrating an auto-tracking operation according to the first embodiment of the present invention.

FIG. 16 is a diagram showing a trace pattern at the time of search in the first embodiment of the present invention.

FIG. 17 is a diagram showing a trace pattern during a search according to the first embodiment of the present invention.

FIG. 18 is a diagram showing a trace pattern during a search according to the first embodiment of the present invention.

FIG. 19 is a block diagram of an embodiment of a main part of the present invention.

FIG. 20 is a diagram showing a case where the same channel is recorded plural times and a 5 × speed is searched according to the present invention.

FIG. 21 is a diagram showing an operation timing when recording the same channel a plurality of times and performing a 5 × speed search according to the present invention.

FIG. 22 is a block diagram illustrating a configuration of a conventional example.

FIG. 23 is an operation diagram at the time of intermittent recording / reproduction with the conventional configuration.

FIG. 24 is an operation diagram during intermittent recording / normal speed reproduction in the conventional configuration.

FIG. 25 is a diagram showing a 5 × speed search in intermittent recording.

FIG. 26 is an operation timing chart at the time of intermittent 4-channel recording / 5-fold speed search in the configuration of the conventional example.

FIG. 27 is a playback screen during intermittent 4-channel recording / 5-fold speed search in the conventional example.

[Explanation of symbols]

4 ... Video switching circuit, 11 ... Cylinder, 12, 13, 1
4, 15 ... Magnetic heads H1 +, H2-, H3-, H4 +, 20,
21, 22 ... Switch circuit, 27 ... Syscon means, 30
... Servo circuit, 32 ... Level detection circuit, 41, 52 ... Sync separation circuit, 42 ... Switching circuit, 43 ... Recording channel control means, 44 ... Recorded video information signal generating / adding means, 45 ...
Recording conversion circuit, 46 ... Logic circuit, 47 ... Reproduction conversion circuit, 48 ... A / D converter, 49 ... Image memory, 50
... D / A converter, 51 ... Encoder circuit, 53 ... Recorded video information detecting means, 54 ... Writing period control circuit, 55 ... Writing control circuit, 56 ... Reference signal generating circuit, 57 ... Read control circuit, 58 ... Envelop detection Circuit, 60 ... Tracking signal generating means, 61, 62 ... Recording track, 63 ... Recorded video information recording position, 64 ... Trace position at the time of search,
66 ... Waveform shaping circuit, 67, 70 ... Phase comparison control circuit,
68 ... Reference signal generator, 69 ... Tracking variable circuit,
71 ... Data processing circuit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tetsuo Sakie 1410 Inada, Katsuta City, Ibaraki Hitachi, Ltd. AV equipment division (72) Minor Ueda 1410 Inada, Katsuta City, Ibaraki Hitachi, Ltd. Factory AV Equipment Division (72) Inventor Yuji Sato 1410 Inada, Katsuta City, Ibaraki Hitachi Ltd. Factory AV Equipment Division (72) Inventor Hideo Nishijima 292 Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa Stock Company Hitachi, Ltd. Inside the Visual Media Research Center

Claims (3)

[Claims] 1. A video switching means for switching a plurality of input video signals in units of fields or frames to generate a series of continuous video signals, and a channel number corresponding to each channel of the plurality of input video signals. Recorded video information generation / addition means for generating a signal indicating recorded video information and adding the recorded video information signal to a predetermined position of the continuous video signal from the video switching means, and output from the recorded video information generation / addition means The rotary magnetic head includes a magnetic recording / reproducing means for recording / reproducing information on / from an oblique track on the tape, and a servo means for controlling the rotation of the magnetic head and the running operation of the tape.
At the time of search reproduction, tracking control of the rotation of the magnetic head and tape running so that the reproduction signal of the portion at the predetermined position to which the recorded video information signal is added can be obtained at a predetermined level or higher. apparatus. 2. A video switching means for switching a plurality of input video signals in units of fields or frames to generate a series of continuous video signals, and a channel number corresponding to each channel of the plurality of input video signals. Recorded video information generation and addition means for generating a signal indicating recorded video information and adding the recorded video information signal to a predetermined position of the continuous video signal from the video switching means, and the recorded video information generation and addition by a magnetic head. A magnetic recording / reproducing means for recording and reproducing an output video signal from the means on an oblique track on the tape, and a reproduction video signal by selectively switching the magnetic head side having a large output level among the reproduction outputs from the magnetic head during search reproduction. A reproduced video signal generating means for generating
Recorded video information detecting means for detecting recorded video information added at the time of recording from the output of the reproduced video signal generating means, A / D conversion of the reproduced video signal, once writing in the image memory, and then D / A conversion. Image memory means for reading,
A writing period control means for controlling a writing period to the image memory means for each video channel according to an output from the recorded video information detecting means, a writing control means for controlling writing to the image memory means, and an image memory Read control means for controlling the reading from the means, and the tape running speed during search / playback is k.times.v (v: normal tape running speed, k
And the servo means for controlling each positive and negative directions are shown), and the tape running multiple speed k at the time of search is defined as the product of the prime numbers Pn, and [Equation 1] | k | = P1l1.P2l2.P3l3・ …… ・ Pnln
(Ln is a natural number), when the number q of video channels input to the video switching means is expressed by the following equation, q = a · Pn (a is a natural number), the magnetic recording / reproducing is performed. A time-lapse magnetic recording / reproducing apparatus characterized in that the number m of video channels recorded by the means is increased or decreased to satisfy the following equation: m ≠ a · Pn (a is a natural number). 3. A video switching means for switching a plurality of input video signals in units of fields or frames to generate a series of continuous video signals, a channel number corresponding to each channel of the plurality of input video signals, and the like. Recorded video information generating / adding means for generating a signal indicating recorded video information and adding the recorded video information signal to a predetermined position of the continuous video signal from the video switching means, in a form adjacent to each other at different azimuth angles. Two magnetic head pairs provided are arranged on the rotating cylinder so as to face each other by approximately 180 degrees, and the magnetic head pair records the video signal output from the recorded video information generating / adding means on an oblique track on the tape. And magnetic recording / reproducing means for reproducing, and for each track reproduced at the time of search reproduction in which the magnetic head pair traces across a recording track. A reproducing track switching signal generating means for generating a signal indicating a switching point, and a reproducing output from the magnetic head pair according to the output from the reproducing track switching signal generating means at the time of search reproduction. Reproduced video signal generation means for selectively switching the head side to generate a reproduced video signal, recorded video information detection means for detecting recorded video information added at the time of recording from the output of the reproduced video signal generation means, and the reproduced video signal Is A / D converted and once written in the image memory, then D /
An image memory means for A-converting and reading, a writing period control means for controlling a writing period to the image memory means for each video channel according to outputs from the recorded video information detecting means and the reproduction track switching signal generating means. When,
Writing control means for controlling writing to the image memory means, reading control means for controlling reading from the image memory means, and tape running speed k × v (v:
And a servo means for controlling the tape running speed in the normal time and the positive and negative values of k indicate the respective forward and reverse direction searches. The writing period control signal is generated on the basis of the reproduction track switching signal, and predetermined. When only the video channel is written to the image memory means and the track in which the same video channel is recorded a plurality of times r times is searched and reproduced,
A time-lapse magnetic recording / reproducing apparatus characterized in that the plurality of times of r times are written in the image memory means as the same video channel.