JPH0669228B2 - Video signal recorder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention provides vertical synchronization signals that are out of phase with each other by 1 / N of one field period of a reference video signal including a reference synchronization signal and a color subcarrier. The present invention relates to a video signal recording apparatus adapted to record N channel video signals and time code signals by N rotary magnetic heads.

[Background technology and its problems]

As a device that captures and records high-speed phenomena
Images for N fields (N is an integer of 2 or more) are taken for each field period, and the time axis is expanded,
An N channel video signal whose phase is shifted by 1 / N of one field period is formed, and these video signals are sequentially formed by N rotary magnetic heads to form adjacent N inclined tracks on the magnetic tape. The applicant of the present application has previously proposed a high-image phenomenon recording apparatus for recording in the above.

By the way, generally, in video tape editing, it is conventionally known that a time code serving as position information (address information) is recorded on a tape in advance, and editing is performed while reading the time code. Such time codes include a longitudinal time code (so-called LTC) recorded on a longitudinal track along the tape running direction of the video tape, and vertical blanking on the video track diagonally formed on the video tape. There is a vertical interval time code (so-called VITC) recorded in each section, and each contains tape position address information indicating hours, minutes, seconds, frames, and the like. This time code is extremely useful because it improves the accuracy of videotape editing, improves efficiency, and enables automatic editing.

When a signal of such a time code is recorded together with a color video signal, a predetermined correspondence relationship is established between the frame address value as the tape position address information and a so-called color frame, that is, so-called color framing. Often required to be taken. As the predetermined correspondence relationship, for example, in the case of the NTSC system, the I and II color frames of four field periods are used.
The relationship is such that the frame address value of a frame composed of fields becomes an even number and the frame address value of a frame composed of fields III and IV becomes an odd number. And when such a relationship is established,
So-called color framing editing can be easily performed, and the editing function can be expanded.

Therefore, even in the high-speed phenomenon recording apparatus, it is required to record the time code signal together with the video signal, and in the case of a color video signal, the color framing correspondence is satisfied. It is desired to record the time code signal.

However, not only it is necessary to provide a time code generation circuit for each of the N-channel video signals, but it is also necessary to correlate each time code data of these N time code generation circuits. Then, there is a drawback that the circuit configuration becomes complicated.

Further, even in the recording of the above-mentioned high-speed phenomenon, the reference sync signal is a 1 × speed equal to the sync signal of the standard television signal, and the video signal and the audio signal are processed for the high-speed recording. Other signals, such as color framing pulse signals, are those for 1x speed. If the color frame synchronization of the time code for high-speed development recording is attempted by using such a color framing pulse, generally, when recording at the N times speed, N times the number of video signal frames is required. Specifically, for example, in the PAL system, the cycle of the color frame is 8 fields, and the pull-in time of the PLL or the like for synchronizing the colors requires 8 fields of the N times speed picture signal.

[Object of the Invention]

In view of the above situation, the present invention is 1 / one of one field period.
When recording N-channel color video signals that are out of phase by N, time code generation can be performed with a simple configuration, and color framing of the time code can be easily achieved, such as PLL for synchronizing. It is an object of the present invention to provide a video signal recording device that requires a short pull-in time.

[Outline of Invention]

That is, the feature of the video signal recording apparatus according to the present invention is that the phase shifts by 1 / N (N is an integer of 2 or more) of one field period of the reference video signal including the reference synchronization signal and the color subcarrier. In a video signal recording apparatus configured to record an N-channel video signal having a vertical synchronizing signal and a time code signal by N rotary magnetic heads, the N-channel video signal is input and the input N signal is input. A synchronization signal separation circuit for forming a high-speed synchronization signal having a period of 1 / N of one field period of the reference video signal based on a vertical synchronization signal of a video signal of a channel, and the high speed formed by the synchronization signal separation circuit. Based on the sync signal and the reference color framing pulse of the reference video signal, a period of 1 / N of the color frame period of the reference video signal is provided. And a high-speed color framing pulse generation circuit for generating a high-speed color framing pulse phase-matched with the reference color framing pulse, and one field of the reference video signal based on the high-speed synchronization signal and the high-speed color framing pulse A time code generating circuit for generating a time code signal having a period of 1 / N and having color frame information phase-matched with the reference color framing pulse, and output from the time code generating circuit. And an inserting circuit for inserting the time code signal into a predetermined section within the vertical blanking section of the N-channel video signal.

Therefore, it is not necessary to provide a time code generation circuit or the like for each channel, and it is possible to generate a time code having a correlation between the channels with a simple circuit configuration. Since the color frame synchronization of the time code is performed by the above-mentioned color framing pulse, it is possible to shorten the time for pulling in the synchronization of the PLL and the like.

〔Example〕

FIG. 1 is a block circuit diagram showing a schematic configuration of a main part of a video signal recording device according to the present invention. In this embodiment, in the case of N = 3, that is, an outline of a main part of a video tape recorder for recording video signals of three channels having vertical synchronizing signals whose phases are shifted by 1/3 of one field period. The example of a structure is shown.

Here, prior to the description of the embodiments of the present invention, recording of the above-mentioned three-channel video signal and high-speed development will be described.

First, when the reference sync signal of FIG. 2A and the reference color framing pulse as shown in FIG. 2B correspond to the reference video signal composed of the reference sync signal and the color subcarrier, FIG. For each field divided by the A pulse, (I) to
(IV) can be numbered and these (I)-
One color frame is composed of four fields of (IV) field. In this case, the correspondence relationship between the frame address value as the time code data (for example, a value of 0 to 29 in the case of NTSC) and the color frame is a predetermined relationship,
For example, the color framing is removed when the relationship that the frame composed of the (I) and (II) fields is an even frame and the frame composed of the (III) and (IV) fields is an odd frame. It is called. To obtain this color framing, see FIG. 2B.
The time code generation may be controlled so that the frame address value of the time code data is set to an even number in accordance with, for example, the fall of the reference color framing pulse.

Next, in order to record a high-speed phenomenon, when using an image pickup device that scans at a speed N times as fast as the scanning speed of the reference video signal, for example, at a speed 3 times higher, this high speed (eg, triple speed)
A high-speed video signal as shown in FIG. 2C is taken out from the image pickup device. In FIG. 2C, the reference synchronization signal (second
One field period of FIG. A) is divided into N (for example, three), and a video signal for one field is compressed and arranged for each divided section. Shows.

Here, the reference video signal does not need to match a standard television signal such as a general NTSC system or a PAL system, and is generally M times the scanning speed of the standard television signal (M is a natural number). do it. In this case, the scanning speed of the imaging device is generally MN times the scanning speed of the standard television signal. In order to simplify the description, the case where M = 1, that is, the scanning speed of the reference video signal is equal to the scanning speed of the standard television signal will be described below as an example.

In this case, the cycle (1 field period) of the vertical synchronizing signal in FIG. 2A is equal to 1 field period (so-called 1V period) of the standard television signal, and the high speed (3
The (double speed) video signal is a signal including a video for one field for each V / 3.

Next, the 3 × speed video signal of FIG. 2C, which is time-axis compressed with respect to the reference video signal as described above, is cyclically distributed to 3 channels, and the time-axis expansion is performed to triple the length, As shown in FIGS. 2D to 2F, three-channel video signals whose phases are sequentially shifted by V / 3 are obtained. The temporal order of the video signals of these three channels is as shown by the numbers 1 to 4 in FIGS. 2D to 2F, and the video of the first to the field constituting one color frame is cyclically distributed to each channel.

As shown in FIGS. 2D to 2F, the 3-channel video signals having the vertical synchronizing signals whose phases are shifted by ⅓ of one field period of the reference video signal are the three video signals shown in FIG. The signal is supplied to the signal input terminals 1, 2 and 3, respectively, and is also sent to the triple speed recording / reproducing system 7 via the VITC inserting circuits 4, 5 and 6 for recording. As the triple-speed recording / reproducing system 7, for example, the high-speed phenomenon recording device previously proposed by the applicant of the present application may be used, and the main part thereof will be briefly described below.

First, as a rotary head device, as schematically shown in FIG. 3, three video heads 31, 32, 33 are arranged at equal intervals (120 ° intervals) so as to face the outer circumference of the rotary drum 30. Use one. The rotation frequency of the rotary drum 30 is equal to the vertical scanning frequency (about 60 Hz in the NTSC system), and video tracks are recorded and formed on the magnetic tape as a recording medium at a rate of three per one field period (between 1V). Will be done. However, since the rotational phases of the video heads 31, 32, 33 are sequentially deviated by 120 °, the tracking operation of the video heads 31, 32, 333 on the magnetic tape 35 is V / 3 as shown in FIG. Will have a phase difference of. The broken line in FIG. 4 indicates the rotational movement direction of the head of the rotary drum 30, and the magnetic tape 35 travels in the direction of the arrow X to relatively move the head tracking direction on the magnetic tape 35. Indicates an arrow Y direction, and video tracks Ta, Tb, Tc are recorded and formed in parallel with the arrow Y direction. By setting the tape running speed at the time of recording to three times the speed at the time of standard (1x speed) reproduction, the recorded video track pattern can be matched with the standard format pattern, and the standard video tape recorder can be used for normal recording. By playing, high speed phenomena can be played in slow motion.

In general, when the reference video signal is set to M times the scanning speed of the standard video signal and the scanning speed of the imaging device is set to MN times the scanning speed of the standard television signal, The rotary drum 30 is provided with N recording video heads, and the drum rotation speed at the time of high-speed recording is a standard M.
By doubling the speed and making the running speed of the magnetic tape 35 the standard MN times, the video track pattern can be matched with the standard track pattern.

Next, a time code generator which is an embodiment of the present invention and is preferably applied to the above-described high speed phenomenon recording apparatus will be described.

The 3-channel video signals respectively supplied to the input terminals 1, 2 and 3 of FIG. 1 are sent to the sync signal separation circuit 11. The sync signal separating circuit 11 takes out the vertical sync signal of each video signal and a horizontal sync signal in the vicinity thereof (to determine whether the field is even or odd), and outputs the vicinity parts of the vertical sync signals for these three channels. Superimpose, V / 3 cycle high speed (3x speed) as shown in Fig. 2G
A sync signal is formed and this high speed sync signal is sent to the time code generation circuit 12. In the time code generation circuit 12, the even-numbered field and odd-numbered field are judged according to the vertical synchronizing pulse of the above-mentioned high-speed (three-fold speed) synchronizing signal and the horizontal synchronizing pulse in the vicinity thereof so that the three-fold speed as shown in FIG. That is, a high-speed frame pulse of 2V / 3 cycle is formed, and the high-speed frame pulse is used for the phase comparator 13
Is sent to one of the input terminals. The phase comparator 13 includes a time constant circuit 14 and a VCO (voltage controlled oscillator) 15,
A PLL (Phase-Locked Loop) circuit for generating the LTC (longitudinal direction time code) bit clock is configured, and the circuit time constant of this PLL system is, for example, tripled according to the above high-speed recording operation. It is set to operate at (frequency). The VCO 15 outputs a clock signal having the bit clock frequency for LTC (or an integral multiple thereof) and is sent to the time code generation circuit 12. In the time code generation circuit 12, the same cycle as the high-speed frame pulse according to the clock signal from the VCO 15
Generates 2V / 3 LTC signal and records this LTC signal at 3X speed /
The word sync signal of the LIC signal is taken out (see FIG. 2I) and sent to the other input terminal of the phase comparator 13 while being sent to the reproduction system 7. Therefore, the phase comparator 13 compares the phases of the high speed frame pulse of FIG. 2H and the word sync signal of FIG. 2I, and the PLL system compares the word sync signal of the LTC signal with the high speed frame pulse. Are controlled to be synchronized.

Further, the 2V / 3-cycle word sync signal shown in FIG. 2I output from the time code generation circuit 12 is sent to the count pulse input terminal of the binary counter 16 and divided by 1/2. , 4V / 3 cycle pulse signal, that is, a high-speed color frame pulse corresponding to triple speed can be obtained. Here, the reference color framing pulse of the above-mentioned reference video signal (see FIG. 2B) is supplied to the other input terminal 8 of FIG. The color framing pulse is sent to the falling edge detection circuit 17 including an inverter and a differentiating circuit to become a falling edge detection pulse as shown in FIG. 2J. This falling detection pulse is a pulse indicating the reference timing of the color framing of the reference video signal, and this is the binary counter 16
Is supplied to the reset terminal of the binary counter 16 so that the counting operation and the output pulse of the binary counter 16 are phase-matched with the reference color framing pulse (FIG. 2B). Therefore, as shown in FIG. 2K, the output from the binary counter 16 falls at the leading edge of the field, with 4 fields of the 3rd to 5th video signal (FIG. 2C) as one cycle. A high-speed (three times speed) color framing pulse with such so-called color frame synchronization is obtained.

The high-speed (3 × speed) color framing pulse of FIG. 2K is sent to the time code generation circuit 12 via the control circuit 18, so that, for example, the high speed (3 × speed) is obtained.
The time code generating circuit 12 forms a time code with a color framing such that the video signal (FIG. 2C) has an even frame in the second field and an odd frame in the second field.

The color framing in this case is 4V / shown in Fig. 2K.
Since the synchronization is performed by the high speed (3 times speed) color framing pulse of 3 cycles, it is about 3 times faster (about 1 / about 3 times) as compared with the case of synchronizing according to the reference color framing pulse (FIG. 2B). It is possible to pull in for generating the time code (in a short time of 3).

In this way, the time-code generating circuit 12 generates the LTC signal and the VITC signal which are color-framed.
Similar to this VITC signal, it has hour, minute, second, frame, and color framing data, and the data changes at a frequency N times that of a normal VITC signal. Here, regarding the VITC signal, the above-mentioned three-channel video signal (Fig. 2D-
F) is a signal of V / 3 cycle which is output at a predetermined timing (for example, 12th H and 14th H) in each vertical blanking section, and this VITC signal is a VITC insertion circuit 4,
It is sent to 5 and 6, respectively. Further, VITC insertion gate pulses from the timing circuit 19 that operates according to the output from the sync signal separation circuit 11 are sent to the control input terminals of the VITC insertion circuits 4, 5 and 6, respectively. The VI corresponds to the predetermined timing of each vertical blanking interval of each video signal of the above three channels by the pulse.
TC signal is inserted respectively.

As described above, when the VITC signal-inserted 3-channel video signal is normally played back at the normal tape speed and the normal rotation speed of the rotary head, the normal speed video signal from each track and the stepwise progress for each track The time code signal to be reproduced is reproduced.

As is clear from the above description, by controlling the operation of one time code generation circuit 17 according to the triple speed for the video signals of three channels whose phases are shifted by V / 3, the inter-channel signals are controlled. The VITC signal in which the correlation of is maintained can be inserted at a predetermined position in the vertical blanking interval of the video signal of each channel, for example, at the 12th H and 14th H (H is the horizontal scanning period), and triple speed The LTC signal for can also be easily obtained. Therefore, for example, 3 for each channel
It is not necessary to use one time code generation circuit,
A configuration for maintaining the correlation of the time code data among these three time code generation circuits is also unnecessary, and the VITC signal and the LTC signal for triple speed can be generated with an extremely simple circuit configuration. Further, regarding the color framing of the time code, the high-speed color framing pulse of 4V / 3 cycle (Fig. 2K) is phase-matched with the reference color fleming pulse (Fig. 2B) and corresponds to the triple speed. Since the color code is synchronized with the time code, the pull-in time when the color frame is synchronized during editing work is short, and the waiting time required until the start of the time code generation is short.

Note that the present invention is not limited to the above-mentioned examples, and in general,
M of standard television signal scanning speed (standard scanning speed)
A rotating video head having N video heads and rotating at a standard M times rotational speed, using a reference video signal having a double scanning speed, and capturing a high-speed video signal imaged at a scanning speed MN times the standard scanning speed. It is needless to say that the present invention can be easily applied to the case of recording by.

〔The invention's effect〕

According to the video signal recording apparatus of the present invention, the VITC signal with respect to the video signal of N channels sequentially having a phase difference of 1 / N field (N is an integer of 2 or more) by a simple circuit configuration for approximately 1 channel. In addition to being able to obtain the LTC signal and the LTC signal, the pull-in time when the color framing of the time code is taken is short, and the waiting time until the start of the time code generation at the editing point at the time of color framing editing is short and the editing efficiency is improved. Can be improved.

[Brief description of drawings]

FIG. 1 is a block circuit diagram for explaining an embodiment of the present invention, FIG. 2 is a time chart for explaining the operation of the circuit of FIG. 1, and FIG. 3 is a rotation of a triple speed recording / reproducing system. FIG. 4 is a schematic plan view showing an example of a head portion, and FIG. 4 is a schematic plan view showing an example of a recording track pattern on a magnetic tape. 1,2,3 ... video signal input terminal, 7 ... 3x speed recording / reproducing system, 8 ... standard color framing pulse input terminal, 11 ... sync signal separation circuit, 12 ... time code generation circuit, 16 ... …counter.

Claims (1)

[Claims] 1. A 1 / N (N is 2) of one field period of a reference video signal including a reference sync signal and a color subcarrier.
In the video signal recording apparatus adapted to record the N-channel video signal and the time code signal having the vertical synchronization signals whose phases are shifted from each other by the above-mentioned integers) by the N rotary magnetic heads, A signal is input, and a synchronization signal separation circuit that forms a high-speed synchronization signal having a period of 1 / N of one field period of the reference video signal based on the input vertical synchronization signal of the N-channel video signal, and the synchronization signal separation circuit Has a period of 1 / N of the color frame period of the reference video signal based on the high-speed sync signal and the reference color framing pulse of the reference video signal formed by the signal separation circuit, and with respect to the reference color framing pulse. High-speed color framing pulse generation to generate high-speed color framing pulse aligned by A circuit and a color frame having a period of 1 / N of one field period of the reference video signal and phase-matched with the reference color framing pulse based on the high-speed synchronization signal and the high-speed color framing pulse. A time code generating circuit for generating a time code signal having information, and an inserting circuit for inserting the time code signal output from the time code generating circuit into a predetermined section within a vertical blanking section of the N channel video signal. A video signal recording apparatus comprising: