JPS61256887A - Recording method for three primary color signal - Google Patents

Abstract

PURPOSE:To remove a dislocation of a hue due to variance in a constant of a matrix circuit or a signal level difference by compressing three primary color signals respectively in a time base, dividing into two tracks to record, and recording the primary color signals as they are without converting to other signals. CONSTITUTION:1H memories 17-22 write and read input primary color signals R, G, B by a writing clock of a repetition frequency f1 and a frequency f2, respectively. The repetition frequencies f1, f2 select the primary color information per 1H so as to transmit within (2/3)H. Time base compression signals alternately read from the 1H memories are synthesized in time series in switch circuits 23-25 and three types of time base compression primary color signals are successively divided to two transmission passages by switch circuits 26, 27. Then, they are supplied to rotating heads 36, 37 through a synchronous pulse and discriminating signal adding circuits 28, 29, an emphasis circuits 30, 31, FM modulators 32, 33 and recording amplifiers 34, 35, to form two tracks at the same time on a magnetic tape individually.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a recording method for three primary color signals, and more particularly to a recording method for recording three primary color signals on a recording medium without converting them into luminance signals, color difference signals, or the like.

2. Description of the Related Art Currently, helical scan type magnetic recording and reproducing devices (VTRs) using 172-inch wide magnetic tapes have relatively narrow recording and reproducing bands for home use, so they cannot record or reproduce luminance signals separated from color video signals. The luminance signal of the carrier color signal is frequency-modulated into a frequency-modulated wave, and the carrier color signal is converted into a low-frequency carrier color signal.

The system employs a so-called low-pass conversion color recording/playback method in which the frequency division multiplexed signal is recorded on a magnetic tape and then played back.Also, to improve tape usage efficiency, adjacent tracks are recorded. It uses a guard panless recording method in which each rotating head has a different azimuth angle. On the other hand, commercial VTRs intended for broadcasting, especially VTRs with built-in cameras, have the same tape width as home VTRs in order to make the device smaller and lighter and to improve the quality of reproduced color video signals. A method is used in which luminance signals and color signals are recorded on separate tracks using separate rotating heads on magnetic tape, and a guard band is provided between adjacent tracks to record and play back the signals. .

FIG. 6 shows an example of a track pattern of such a conventional camera-integrated VTR. On the magnetic tape 1, FM luminance signal recording tracks 2+ and 22 and FM color difference signal recording tracks 3+ and 32 are recorded and formed by rotating heads, respectively. is,
Also, along the tape longitudinal direction, audio track 4+
+ 42 + A control track 5 and a time code track 6 are respectively formed. Tracks 21 and 31
are tracks on which the FM luminance signal and FM color difference signal of the same field are recorded simultaneously and separately.Similarly, tracks 22 and 32, and tracks 23 and 33 are the tracks where the FM luminance signal and FM color difference signal of the same field are recorded, respectively. These are tracks recorded simultaneously and separately. Furthermore, a guard band (no signal recording zone) is formed between adjacent tracks.

On the other hand, the present applicant previously filed Japanese Patent Application No. 60-35827,
By recording the three types of signals that make up the color video signal by forming separate tracks in two areas separated in the upper width direction of the tape, and reproducing these, a track pattern such as the one shown in FIG. 6 is created. Conventional camera integrated V
We have proposed a color video signal recording and reproducing device that solves all the problems of TR. FIG. 7 shows an example of a track pattern produced by the color video signal recording and reproducing apparatus proposed by the present applicant. In the figure, a magnetic tape 7 with a tape width of 172 inches has two channels of audio tracks 8+ and 82 along the tape longitudinal direction at the top end of the tape by a fixed head, and a time code track 9 and a control track 10 at the bottom end of the tape. are recorded respectively. The tape width between the lower edge of the audio track 81 and the upper edge of the time code track 9 is divided into two recording areas W1 and W2, and an FM luminance signal is recorded in the recording area W+ by a rotating head for luminance signals. The inclined tracks Tv+ to Tv+s are formed sequentially at an angle θ with respect to the longitudinal direction of the tape without a guard band.On the other hand, in the upper recording area W2, an FM color difference signal is recorded by a rotating head for color signals. Recorded inclined track Tc+~T
The CIs 6 are sequentially formed at an angle θ with respect to the longitudinal direction of the tape without a guard band.

Problems to be Solved by the Invention In each of the track patterns shown in FIGS. 6 and 7, the luminance signal is recorded in a wide band, and the two types of color difference signals are recorded in a narrow band. This method utilizes the visual characteristics of the human eye and is very effective in effectively utilizing the transmission band. However, for example, in image processing by a computer, etc.
Since the three primary color signals are treated equally, it is desirable that each of the three primary color signals be broadband. In addition, when converting the three primary color signals into a luminance signal and two types of color difference signals and transmitting them, and inversely converting them in the receiving system (reproducing system) to obtain the three primary color signals,
There is a problem in that accurate color reproduction cannot be performed if there are variations in the signal level or constants of the matrix circuit during conversion and inverse conversion. For this reason, it is conceivable to record each of the three primary color signals separately on three tracks, but this has the problem of increasing the number of rotating heads and complicating the apparatus.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a three-primary-color signal recording method that solves the above-mentioned problems by compressing the time axis of each of the three primary-color signals, distributing them to two tracks, and sequentially recording them.

Means for Solving the Problems The three primary color signal recording method according to the present invention compresses the three primary color signals in the time axis at a predetermined time axis compression ratio, and stores the time axis compressed three primary color signals on two tracks on a recording medium. Take pictures and record them one after another.

The working three primary color signals have 2 color information for 1 horizontal scanning period (1H).
The time axis is compressed so that it is transmitted within a period of /3H, and the time axis compressed three primary color signals are alternately distributed to two transmission paths, synthesized in time series, and recorded alternately on two tracks. Ru.

Therefore, the number of heads may be the same as that of the apparatus for forming the track pattern shown in FIGS. 6 and 7, and the three primary color signals can be recorded in a wide band without complicating the head mechanism. An embodiment of the present invention will be described below with reference to the drawings.

Embodiment FIG. 1 shows a block system diagram of an embodiment of the present invention. In the same figure, input terminals 11, 12 and 13 have a primary color signal (red signal) R2 for red among the three primary colors of red, green and blue.
A primary color signal G for green (green signal) and a primary color signal B for blue (blue signal) are input separately and simultaneously. This situation is schematically shown in FIG. 2(A). In Figures 2 and 3, the encircled numbers indicate the scanning line numbers in the screen, so for example ■R is 1 of the scanning line number "1".
Indicates that this is a primary color signal related to H red information. In addition, in FIG. 1, a composite synchronization signal is input to the input terminal 14,
Various timing pulses (for example, write clock pulses and read clock pulses) are supplied to the timing pulse generation circuit 15, and are phase-synchronized with each horizontal and vertical synchronization signal.

switching pulses, etc.), and is also supplied to a synchronization pulse and discrimination signal generation circuit 16, which will be described later.

The red signal R that entered the input terminal 11 is the 1H memory 17.
The green signal G input to the input terminal 12 is supplied to the 1st memory 19 and 20, respectively, and is input to the input terminal 1.
The blue signal B input into 1H memory 21 and 22 is supplied to 1H memory 21 and 22, respectively. The 1H memories 17 to 22 input the primary color signal at the repetition frequency f1 from the timing pulse generation circuit 15.
performs a write operation based on the write clock of
The readout operation of the written primary color signal is performed based on the readout clock with the repetition frequency f2, but since fl is selected here as f2, the time axis is f+/fz.
Outputs a time-domain compressed primary color signal. Also, the daily memory for each primary color signal is 17 and 18.19.
The reason why two are provided as shown in 21 and 22 is that it is necessary to write the primary color signals for the current horizontal scanning period even while the 1H memory is performing a read operation. , the two one-day memories are configured to perform write and read operations alternately.

Now, as an example, if we consider one horizontal scanning period of an NTSC color video signal, its 111 periods (= 63.5
The signal waveform of 56us') is as shown in Figure 4, and 1
It is well known that a day consists of a horizontal blanking period of 10.9JIs followed by a video period (image information transmission period) of 52.656μ9. Here, in order to be able to transmit the primary color information per day within (2/3)H, the repetition frequencies f1 and f2 are set to f+ = 0.7f2.
Assuming that the signal with a video period of 52.656 us is time-axis compressed, the time-axis compressed primary color signal of the video period will be transmitted in 36.859 埒 (= 52.656 μs x 0.7). . This transmission period is 36,859il
s is <2/3) compared to 11[43,3711 of H, and 5
．． It was 512 horses shorter and was taken out with a margin of 5.512 IJs.

The rI axis compressed red signals alternately read out from the 1H memories 17 and 18 are synthesized in time series by the switch circuit 23 and supplied to the terminal 26a of the switch circuit 26 and the terminal 27a of the switch circuit 27. The time-base compressed green signals read out alternately from 19 and 20 are synthesized in time series by a switch circuit 24, and then supplied to terminals 26b and 27b of switch circuits 26 and 27, respectively.
Furthermore, the time-base compressed blue signals read out alternately from the 1H memories 21 and 22 are synthesized in time series by the switch circuit 25, and then sent to terminals 26c and 2 of the switch circuits 26 and 27.
7c, respectively. The switch circuits 26 and 27 perform switching control every (2/3)H based on the switching pulse from the timing pulse generation circuit 15 so that the three types of time-axis compressed primary color signals are sequentially and alternately distributed to the two transmission paths. be done. As a result, the switch circuit 26
From there, three types of time-axis compressed primary color signals are synthesized and extracted in a time-series manner in the order schematically shown in FIG. 2(B).
On the other hand, from the switch circuit 27, three types of time-base compressed primary color signals are chronologically synthesized and taken out in the order schematically shown in FIG.

Each output time-division multiplexed signal of the switch circuits 26 and 27 is supplied to a synchronization pulse and discrimination signal addition circuit 28 and 29, where the non-transmission period 5 of the time-axis compressed primary color signal within the (2/3)H period mentioned above is supplied. .5121Js, a synchronizing pulse and a discriminating signal from the discriminating signal generating circuit 16 are inserted and added, respectively, to obtain a signal having a waveform as shown in FIGS. 3(A) and 3(B).

In FIGS. 3(A) and CB), a1 to a4. b1 to b3 indicate the above synchronization pulses, C4 and C4, 02, respectively.

dl indicates the above-mentioned discrimination signal. The above synchronization pulse serves as a reference signal for determining the start position of writing to the 1H memory when performing time axis expansion to restore the time axis compressed primary color signal to the original time axis during playback. The amplitude from the initial value to the defined level immediately after the synchronization pulse can be used as the reference level for the DC level during reproduction. Furthermore, the above-mentioned discrimination signal is immediately before a predetermined negative time-axis compressed primary color signal (time-axis compressed red signal in the examples of FIGS. 3(A) and 3(B)) among the three types of time-axis compressed primary color signals. This is a 2H cycle burst signal that is superimposed on the synchronization pulse of It can also be used as a pilot signal to determine the start position of writing to the 1-day memory, or to accurately match the phase of the clock pulse to the 1H memory during playback with the phase of the clock pulse during recording.

The multiplexed signal as shown in FIG. 3(A) extracted from the synchronization pulse and discrimination signal addition circuit 28 and the multiplexed signal as shown in FIG. 3(B) extracted from the synchronization pulse and discrimination signal addition circuit 29 are , as shown in FIG. 1, emphasis circuits 30, 31 . FM modulators 32, 33. recording amplifier 3
4.35, and are separately supplied to the rotary heads 36 and 37, and are recorded separately and simultaneously forming two tracks on the magnetic chip 738. 2 tracks are 1
A new one is formed for each field. As a result, the resulting recording track pattern becomes similar to the track pattern shown in FIG. 6 or 7. However, whereas in FIGS. 6 and 7, the FM luminance signal and the FM color difference signal are recorded on two inclined tracks that are recorded separately and simultaneously, in the present invention, the FM luminance signal and the FM color difference signal are recorded separately and simultaneously. The difference is that a broadband FM signal frequency-modulated with a signal obtained by time-division multiplexing of time-axis compressed primary color signals is recorded on the two inclined tracks that are recorded at the same time.

Note that the rotating heads 36 and 37 (as well as 40.
41> each consists of two rotating heads.

Next, a reproduction system for the three primary color signals recorded according to the present invention will be explained with reference to a block system diagram shown in FIG. In the figure, recorded FM signals on two tracks of a magnetic chip 738 are reproduced simultaneously and separately by rotary heads 40 and 41, and are supplied to an FM demodulator 44.45 through a preamplifier 42.43. , where it is FM demodulated. FM
The first reproduced time-division multiplexed signal taken out from the demodulator 44 is passed through a de-emphasis circuit 46 to a one-day memory 48.
50 and 52, respectively, and is also supplied to a synchronization pulse and discrimination signal detection circuit 54.

Similarly, the second reproduction time division multiplexed signal taken out from the FM demodulator 45 is supplied through the de-emphasis circuit 47 to the daily memories 49, 51 and 53 and the synchronization pulse and discrimination signal detection circuit 54, respectively. The synchronization pulse and discrimination signal detection circuit 54 detects the above-mentioned synchronization pulse and discrimination signal from the first and second reproduction time division multiplexed signals, respectively, and supplies the detection signals to the timing pulse generation circuit 55. Here, various timing pulses (clock pulses and switching pulses) are generated and a composite synchronization signal is generated, which is output to the output terminal 62.

The 1H memories 48, 50 and 52 determine whether the time-axis compressed primary color signals in the first reproduction time-division multiplexed signal are a red signal, a green signal, and a blue signal based on the clock pulse of the repetition frequency f2 from the timing pulse generation circuit 55. Similarly, the memory capacity per day is 49.5.
1 and 53 each perform a write operation based on a clock pulse of repetition frequency f2 when the time axis compressed primary color signals in the second reproduction time division multiplexed signal are a red signal, a green signal, and a blue signal. In addition, the 1H memories 48 to 53 each store the time axis compressed primary color signals written in the (2/3)H period.
Based on the clock pulse of the repetition frequency f1 from the timing pulse generation circuit 55, the time axis is extended to the original time axis and read out in the video period.

Here, the timing pulse generation circuit 55 generates data for writing into the 1H memories 48 to 53 based on the timing generated based on the time reference and the transmission primary color signal identification information obtained from the synchronization pulse and the detection signal from the discrimination signal detection circuit 54. Each output timing of the clock pulse and the readout clock pulse is performed appropriately, and for example, the scanning line number ■ in the reproduced first time division multiplexed signal which comes in the order schematically shown in FIG. 2(B). 1H during the time axis compressed red signal transmission period.
A clock pulse for writing is supplied to the memory 48, and transmission is started H/3 after that, and time axis compression of the scanning line number ■ in the reproduced second time division multiplexed signal schematically shown in FIG. 2(C) is performed. During the green signal transmission period, a clock pulse for writing is supplied to the 1H memory 51, and furthermore, the time axis compressed blue signal transmission period of the scanning line number ■ in the reproduction first time division multiplexed signal, which starts transmission H/3 later. Inside, a writing clock pulse is supplied to the 1H memory 52, and the scanning line number in the reproduced second time-division multiplexed signal, which is transmitted after H/3, is supplied.
During the time axis compressed red signal transmission period, a clock pulse for writing is supplied to the memory 49 for one day, and thereafter the H
Every time /3 elapses, 1H memory 50 → 53 → 48 → 51 →
Write clock pulses are supplied for each (2/3)H period in the order of 52→49→....

Further, the timing pulse generation circuit 55 is connected to the 1H memory 52.
By supplying the same read clock pulse for 114 periods to the 1H memories 48, 51 and 52, respectively, at the time when the write operation of 1H memory 50 is completed (the time when the 1H memory 50 starts the write operation), the same scanning line number ( For example, the three primary color signals of
By supplying the same read clock pulse for 1H period to the memories 49, 50 and 53, respectively, at the time when the memory 51 starts the write operation, the next same scanning line number stored in them is read. The three primary color signals are read out simultaneously.

Further, the timing pulse generation circuit 55 is connected to the switch circuit 5.
6. Apply switching pulses to 57 and 58, respectively,
Switching control is performed to selectively output the readout primary color signals of the three 1H memories performing the readout operation among the 1H memories 48 to 53. As a result, the output terminals 59-61 from the switch circuits 56-58 are connected to the output terminals 59-61 in FIG.
), the reproduced three primary color signals returned to their respective time axes are taken out in parallel in the order of the scanning line numbers.

Note that the present invention is not limited to the above-described embodiment; for example, the discrimination signal is as shown in FIG. 3(A).

It does not have to be a burst signal as shown by C+, C2, and d+ in (B), but only the pulse width of the synchronizing pulse immediately before a predetermined type of time-axis compressed primary color signal among the synchronizing pulses a1 to a4 and b1 to b3. The transmitted primary color signal may be determined by making the pulse width different from that of other synchronizing pulses.

Effects of the Invention As described above, according to the present invention, each of the three primary color signals can be recorded in a relatively wide band without complicating the recording system or head structure compared to the conventional two-track video signal recording device. It is possible to record the three primary color signals as they are without converting them to other signals, so this problem is likely to occur when the three primary color signals are converted into a luminance signal and two types of color difference signals for recording, and then inversely converted in the playback system to obtain the three primary color signals. , which does not cause hue shift due to relative level differences in each of the three primary color signals or variations in the constants of the matrix circuit, has good color reproducibility, and can obtain high-quality reproduced color images. It is.

[Brief explanation of drawings]

FIG. 1 is a block system diagram showing one embodiment of the present invention, and FIG.
The figure is a diagram schematically showing the signals of each of the nine essential parts of the block system illustrated in Figures 1 and 5, Figure 3 is a signal waveform diagram for explaining the operation of the block system illustrated in Figure 1, and Figure 4 is the NTSC system. FIG. 5 is a block system diagram showing an example of a reproduction system for reproducing the three primary color signals recorded according to the present invention, and FIG. 6 is a conventional camera-integrated VT.
FIG. 7 is a diagram showing an example of a track pattern in R. FIG. 7 is a diagram showing an example of a track pattern of a color video signal recording/reproducing apparatus previously proposed by the present applicant. 11-13... Primary color signal input terminal, 14... Composite synchronization signal input terminal, 15.55... Timing pulse generation circuit, 16... Synchronization pulse and discrimination signal generation circuit,
17~22.48~53...1H memory, 23~27
．． 56-58... Switch circuit, 28.29... Synchronous pulse and discrimination signal addition circuit, 32.33... FM
Modulator, 36.37, 40.41... Rotating head, 3
8... Magnetic tape, 59-61... Reproduction primary color signal output terminal, 62... Reproduction composite synchronization signal output terminal.

Claims (1)

[Claims] The color information per horizontal scanning period of the three primary color signals is 2/3 each.
The three primary colors are characterized in that the three primary color signals are time-axis compressed so as to be transmitted within a horizontal scanning period, and the time-axis compressed three primary color signals are sequentially and alternately distributed and recorded on two tracks on a recording medium. Signal recording method.