JPS6242683A - Video signal recording device - Google Patents

Abstract

PURPOSE:To record and reproduce a signal in a high frequency band without expanding a frequency band by separating high and low frequency components from an input luminance signal, obtaining a low band wave from the high frequency component by means of a balance modulator and adding said wave to said low frequency component so as to frequency-modulate. CONSTITUTION:The 1st low-pass filter 2 extracts the high frequency component from a high frequency luminance signal. The 1st subtractor 3 substracts the high frequency component from the high frequency luminance signal to obtain the low frequency component. After the balance modulator 5 balance-modulates the high frequency component with the aid of a reference signal from a recording reference signal generator 4, a low-pass filter 6 takes out the lower band wave. An adder 7 adds the lower band wave to the low frequency component so as to multiplex them.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a single-image recording/reproducing apparatus, and particularly to a high-resolution single-image recording/reproducing apparatus.

BACKGROUND OF THE INVENTION An image recording and reproducing device for an electronic still camera, which was largely standardized in May 1980, will be described. FIG. 6 shows the basic configuration of an image recording and reproducing device for an electronic still camera, in which 51 is a luminance (1) signal input terminal, 31 and 32 are R-Y and B-Y color difference signal input terminals, and 52 is a low frequency signal input terminal. Pass filter (LPF), 33 is a line sequential circuit, 63
．． 34 are FMs for luminance signals and line-sequential color difference signals, respectively.
Modulator, 64 is an adder, 9 is a recording amplifier, 1o is a recording/reproduction changeover switch, 11 is a magnetic head, 12 is a magnetic sheet, 13 is a disk motor, 14 is a head amplifier, 36 is a high-pass filter, 3a is a Low pass filter, 15.3
8 is an FM demodulator for luminance signals and line sequential color difference signals, 39 is an inverse line sequential circuit, 40 is an encoder, and 55 is a standard television signal output terminal. Next, the operation will be explained. During recording, the luminance signal to which the synchronization signal is added is input to the input terminal 51. After the band is limited by the LPF 52), the luminance signal FM modulator 53 inputs the luminance signal to the FMg: and tonality general adder 64. It will be destroyed. On the other hand, the R-Y color difference signal and the B-Y color difference signal led to the input terminals 31 and 32 are processed by the line sequential circuit 33 for each horizontal period, on the line 1 on which the R-Y color difference signal and the B-Y color difference signal appear. It is converted into a sequential color difference signal, FM-modulated by an FM modulator 34 for line-sequential color difference signals, and guided to an adder 54.
It is added to the M modulated luminance signal, and the recording amplifier 9. Recording is performed by a magnetic head 11 via a recording/reproduction changeover switch 10 on a magnetic sheet 12 that is rotated by a motor 13 . .

Note that the bands occupied by the FM modulated luminance signal and the FM modulated line sequential color difference signal are as shown in FIG.
．． It is said to be 5MH. The sync chip frequency of the luminance signal is 6MHz, and the white peak frequency is 5M.
The center frequency of 1-IZ, Ry color difference signal is 1.2 Ml
-17,B -Y color difference signal center frequency is 1.3MHX
! It is said that There is a limit to the band of luminance signals that can be recorded and played back in a recording/playback system with a fixed band in this way.
4.6M1-(z (approximately 36o in terms of horizontal resolution)
'ry books). The reason why the band is restricted in the standard is that there is a limit to the band that can be recorded and reproduced by a magnetic head and a magnetic sheet.

Furthermore, when attempting to perform FM modulation by inputting a high-band luminance signal to a recording system in which the frequency band and frequency arrangement of the FM modulated wave have been determined in this way, false signals such as aliasing distortion occur and the image quality deteriorates. .

In order to prevent this, an LPF is placed between the luminance signal input terminal 61 and the 7M modulator 53 to increase the band of the luminance signal input to the 7M modulator 53 up to the highest frequency that can be recorded and reproduced by this recording and reproduction system. is limited to. Therefore, the cutoff frequency of the LPF in FIG. 6 is designed to be about 4.5 M@Z.

Next, during reproduction, the signal recorded on the magnetic sheet 12 is reproduced by the magnetic head 11 and amplified by the head amplifier 14 via the recording/reproduction changeover switch 1Q. Then, the output of the head amplifier 14 is changed to 2.
Components of 5M14 or more are separated, FM demodulated by a luminance signal FM demodulator 16, reproduced as a luminance signal iN, and guided to an encoder 40.

On the other hand, the output of the output amplifier 14 is also guided to the LPF 37,
FM for line-sequential color difference signals in which components below 2.5M are separated.
The demodulator 38 performs FM demodulation into a line sequential color difference signal, and the reverse line sequential circuit 39 reproduces the R-Y color difference signal and the B-Y color difference signal, which are led to the encoder 40 and encoded together with the luminance signal. The signal is output from the output terminal 66 as a standard television signal. Note that the recording/playback selector switch 10
It is assumed that is switched to the terminal R side during recording and to the terminal P side during playback.

Problems to be Solved by the Invention In the conventional image recording and reproducing apparatus having the configuration described above, the band of luminance signals that can be recorded and reproduced is approximately 4.5 Ml-IZ (approximately 35 o'rv lines in terms of horizontal resolution). , cannot meet demands for higher resolution. Furthermore, there is a strong demand for even higher resolution for devices that record and reproduce still images, such as electronic still cameras. To cope with this, it is necessary to take measures such as increasing the recording capacity of the recording medium (in this case, a magnetic sheet) and changing the standard.

The present invention solves the above-mentioned problems and provides a high-resolution image recording and reproducing apparatus that uses the recording medium as it is, without making any major changes to the standards, and that communicates with the current standards. The aim is to provide a recording device.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a separating means for separating high frequency components and low frequency components of an input luminance signal, and a separating means for separating the high frequency components and low frequency components. and a balanced modulator that balance-modulates a reference signal having a frequency that is an odd multiple of a frequency that is half of one horizontal scanning frequency with the high frequency component, and a low-pass filter that obtains a lower side band of the modulated output of the balanced modulator. and an adder for adding the low frequency component and the output signal of the low-pass filter, a frequency modulator for frequency modulating the output of the adder, and means for recording the output of the frequency modulator on a recording medium. This is a video signal recording device.

The present invention also provides a second frequency modulator that obtains a frequency modulated chromaticity signal occupying a band lower than a band of the frequency modulator output signal from one line-sequentialized chromaticity signal; a second adder that mixes the frequency-modulated chrominance signal and the frequency-modulated chrominance signal to obtain a modulated color video signal; 1. This is a color video signal recording device provided with means for recording this second adder output signal on a recording medium.

Effect The present invention has the above-described configuration, and the high-band luminance signal (band o
-fM) is the frequency fc that can be recorded and reproduced by the recording/reproducing system.
Separate into the following low frequency component YL times signal band 0~fc) and high frequency component YH times signal band fc-fM) above fc),
A lower frequency than the YH multiplied signal fc and a horizontal scanning frequency f
, by harmonizing the frequency at an odd multiple of half the frequency of , and obtaining its lower sideband, the band changes from f, -f, to h fs(
<fc) modulated high-frequency luminance signal YH' is obtained, and this YH/
By adding the signal and the YL times signal, the band becomes 0.
~fc, a signal containing information on both the low frequency component and the high frequency component of the high band luminance signal is obtained, and this signal is recorded on a recording medium. The frequency spectrum of this recorded signal has energy concentrated at frequencies that are integral multiples of the YL multiplied signal fH, and the energy of the Y)1' signal is concentrated at frequencies that are odd multiples of fH/2. It is possible to separate the YL times signal YH/signal by using
It is possible to reproduce a high band luminance signal from the YL multiplied signal Y and the signal by reproducing the signal.

Furthermore, the present invention is applied to a method in which a line-sequential color difference signal is FM-modulated and multiplexed onto a luminance FM modulated wave for recording, thereby making it possible to increase the bandwidth of the luminance signal of a color image.

Embodiment FIG. 1 is a block diagram showing a first embodiment of the present invention. In FIG. 1, 1 is a high-band luminance signal input terminal, 2 is a first high-pass filter (HPF), 3 is a first subtractor, 4 is a recording reference signal generator, 5 is a balanced modulator, and 6 is the first
7 is a first adder, 8 is an FM modulator, 9 is a recording amplifier, 10 is a recording/reproduction changeover switch, 1
1 is a magnetic head, 12 is a magnetic sheet, 13 is a disk motor, 14 is a head amplifier, 1 is an FM demodulator, 16 is a horizontal scanning period delay circuit (IHD, L,), 1γ is a second
18 is a second reducer, 19 is a reproduction reference signal generator, 20 is a synchronous detection circuit, 21 is a third adder, 2
2 is an output terminal for a high band luminance signal. During recording, as shown in Fig. 2 (a), which is input to the input terminal, a high band luminance signal Y having a band up to the highest frequency fM has a frequency of 10 or more as shown in Fig. 2 (c). High frequency component YH times signal 1st. Extracted with DHPF. and the first
The subtracter 3 subtracts the YH times signal from the Y signal, and the result is shown in Figure 2 (
As shown in b), a low frequency component y, - signal with a band fci is output. On the other hand, after being balanced modulated by the YH multiplied signal balanced modulator 5 with the reference signal of frequency fs' from the recording reference signal generator 4, the lower sideband is extracted by the first LPF 6, as shown in FIG. 2(d). The upper modulated high-frequency luminance signal YH' is frequency-converted as shown in FIG.
As shown in FIG. 2 (0), the frequency band is 45 at maximum fc, but a signal containing both YLfj and YH times information is obtained. , it should be noted that the frequency f is shown in Figure 2 (C).
The power of.

The frequency is lower than the off frequency fc and is selected to be an odd multiple of half the frequency of the monthly horizontal Ill circle frequency.

Therefore, if the frequency axis of the output signal of the first adder 7 is expanded as shown in FIG. Yl(' of the signal]-energy is fI(//2
It concentrates on frequencies that are odd multiples of , and is in a frequency iterator relationship. The output signal of the first 1lIll calculator γ is 7M
The frequency spectrum of the FM modulated wave 1, which is FM modulated by the modulator 8, is shown in FIG. / is assumed to match the band of the FM modulated wave of the luminance signal. The output of the 7M modulator 8 is sent to the recording amplifier/record/playback switch/f edge 1Q, magnetic field, 2. via de 11,
The data is recorded on the magnetic sheet rotated by the scouring motor 13.The recording/reproduction changeover switch 10 is set to the R terminal [11+1] during recording, and to the R terminal [11+1] during re-setting (iP stop; needle completion side). jd,continued-r-i・“).

During reproduction, the signal reproduced by the magnetic head 11 is sent to the head amplifier 1 via the recording/reproduction switch 10.
4, and then FM demodulated by the FM demodulator 15 and the second
A signal in which YL times signal yH/times signal is multiplexed as shown in FIG. 6 is reproduced. And this multiplex signal is IHD
A separation circuit (<C-shaped filter) composed of L16, a second adder 17, and a second subtracter 18 generates the YL multiplied signal YH'
Separated into signals.

This separation circuit (<1., type filter) is well known, but will be briefly explained. Since the YH' signal is balanced modulated at a frequency fs that is an odd multiple of fH/2, the phase is reversed every -water period. Therefore, when the output signal of the i HD L16 and the output of the FM demodulator 16 are added in the second adder, the yH/signal is removed and the Y signal can be extracted, and when subtracted in the subtracter 18, the YL signal can be removed and the YH' signal is removed. 3 from which the signal can be extracted, and this YH' signal has the same frequency f as the recording reference signal generated by the reproduction reference signal generator 19.
At s, synchronous detection is performed by the synchronous detection circuit 2Q using the reproduction reference signal having the same phase, and the high-frequency luminance signal YH is reproduced. This YH multiplied signal and the YL multiplied signal output from the second subtracter 1γ are added by the third adder 21, and a high band luminance signal Y is outputted to the output terminal 22. In this way, without increasing the frequency band of the signal recorded on the recording medium compared to the conventional example, by skillfully utilizing the properties of television signals, it is possible to record and reproduce signals in the υ higher band than in the conventional system1. , FIG. 3 is a professional diagram showing another implementation of the present invention, and the difference from FIG. 1 is that the information of the recording reference signal is time-multiplexed in the intermittent period (blanking period) of the image signal. The structure is such that a reference signal for reproduction is created by recording the same signal and distorting the signal at the time of reproduction. Only the differences from FIG. 1 will be explained. 23 is a synchronization signal input terminal, 24 is a recording burst gate pulse generation circuit, 25 is a first gate circuit, 26 is a fourth adder, 2 is a synchronization separation circuit, 28
Reference numeral 29 denotes a reproduction burst gate pulse generation circuit, 29 a second gate circuit, 30 a reproduction reference signal generation circuit, and 46 a blanking circuit. During recording, based on the synchronization signal input to the terminal 23, the recording burst gate is used to gate the recording reference signal in the gate circuit 25 for an arbitrary period of the granging period of the video signal in the recording burst 1 and the gate generation circuit 24. The pulsed recording reference signal is added with the low frequency component YL multiplied signal modulation high frequency luminance signal Y, / of the luminance signal by the fourth adder 26, and this multiplexed signal undergoes the same process as shown in FIG. recorded on a recording medium.

During reproduction, a synchronization signal among the signals output from the 7M modulator 15 is separated by a synchronization separation circuit 27. Based on this synchronization signal, a reproduction burst gate pulse is generated by a reproduction burst gate generation circuit 28, and this pulse 2nd by
Of the signals output from the subtracter 18, a reproduced burst-like reference signal is extracted by a gate I-circuit 29, and a continuous reproduced reference signal is generated by a reproduced reference signal generator 3o based on this reproduced burst-like reference signal. generated. - Old handwriting 2 subtractor 18
The output from the output is blanked by the graphing/king circuit 46, where the reproduced burst gate pulse number 1n portion is blanked, and the reproduced modulated high-frequency luminance signal yH/ is taken out. Even during playback, other operations and configurations are the first
It is the same as the figure. 3 The configuration of Figure 3 like this! l: Due to time axis fluctuations caused by uneven rotation of the motor 13 during recording and reproduction.

It has the characteristic that Yn' can be synchronously detected without error even if the phase and frequency e of the reference signal vary between recording and reproduction.

Figures 4 and 5 show other embodiments of the present invention. A color image recording and reproducing method in which the actual iAρ values shown in FIGS. 1 and 3, respectively, are subjected to full FM modulation of the linear color difference signal explained in the conventional example section, multiplexed onto the luminance FM modulated wave, and then recorded and reproduced. This system is applied to the conventional column in Fig. 6 and the conventional column in Fig. 4 to increase the bandwidth of the luminance signal of a color image.
Since this is a combination of the implementation rows of the present invention shown in FIG. 5, the illumination will be omitted.
The reference signal fs is lower than the cut 47 frequency fc of the HPF and f. ,・I explained that a frequency that is an odd multiple of '2 is sufficient, but in the NTSC television system:・The number of numbers u3, +J and the color subcarrier f S
G (”3-5 7 9 5 4 5 M)l
If it is used as a z-, : 5 2 6 - signal, there is an advantage that there is no need to separately provide a recording reference signal generator. This effect is particularly great in devices such as electronic still cameras that are integrated with an imaging section because the imaging section includes a synchronization signal generator that generates this color subcarrier.

Furthermore, in the implementation sequence explained above, the low frequency component YL of the luminance signal
The signal is obtained by simply subtracting the high-band luminance signal YH from the double signal and the high-band luminance signal Y, but as it is, it is shown in Fig. 2 (f”
As shown in Figure 1, there is a small amount of YL signal energy at frequencies that are odd multiples of fH/2, and when the YL multiplied signal y,/signal is separated during playback, a little crosstalk occurs and the playback is interrupted. There will be some interference in the image. In order to eliminate this, in the embodiments shown in FIGS. 1 and 4, the first subtracter 3 and the first adder 7 must be connected, and in the embodiments shown in FIGS. A pre-comb filter may be inserted between the subtracter 3 of 1 and the fourth adder 26 to remove frequency components that are odd multiples of fHI3 in the YL signal.

Furthermore, in the embodiments described above, the configuration of a recording/playback device having a recording/playback switch has been explained. It is clear that it is also good.

Furthermore, in the implementation sequence described above, the separation circuit that separates the high frequency component y++ signal and the low frequency component YL times the signal from the input luminance signal was explained as being composed of the 10th HPF 2 and the first subtractor 3, but it is not necessary to use this method. It is clear that it may be configured in any other way. As a method for this, there is a simple method of obtaining a YL times signal from the H P F fYH signal using an LPF.

As described in detail, according to the present invention, high-band signals can be recorded by skillfully utilizing the characteristics of television signals without increasing the frequency band of signals recorded on a recording medium compared to the conventional example.・Can be played back and high resolution can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an FIJ that implements the present invention, and FIG.
The figures are waveform diagrams, FIGS. 3 and 4, for explanation. FIG. 5 is a block diagram showing another embodiment 11tlJ of the present invention, FIG. 6 is a block diagram of a recording/reproducing section of a conventional electronic still camera, and FIG. 7 is a recording frequency allocation diagram of a conventional electronic still camera. It is. 2...HPF, 3...subtractor, 4...
. . . Recording reference signal generator, 5 . . . Balanced modulator, 6 . . LPF, 70. ...adder, 8...
...FM modulator, 9... Recording amplifier, 1Q.
...Record/playback selector switch, 11...Magnetic head, 12...Magnetic sheet, 13...
Disc motor, 14... Head un7', 1
5.°...FM demodulator, 17...Adder, 18
...Subtractor, 19..Reproduction reference signal generator, 20.
...Synchronous detection circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure (ZKuriki Σ (z flatness --J Figure 6 Figure 7

Claims (6)

[Claims] (1) Separating means for separating high frequency components and low frequency components of an input luminance signal; a balanced modulator that balance-modulates a reference signal with the high-frequency component; a low-pass filter that obtains a lower band of the modulated output of the balanced modulator; and an output signal of the low-frequency component and the low-pass filter. 1. A video signal recording device comprising: an adder for adding , a frequency modulator for frequency modulating the output of the adder, and means for recording the output of the frequency modulator on a recording medium. (2) A patent in which the adder is configured to add a burst-like reference signal obtained by extracting the reference signal for an arbitrary period of the blanking period of the input luminance signal, a low frequency component, and an output signal of a low-pass filter. A video signal recording device according to claim 1. (3) Claim 1 or 2 characterized in that the input luminance signal is a luminance signal of the NTSC television system, and the frequency of the reference signal is the same as the color subcarrier frequency in the NTSC television system. The video signal recording device described in Section 1. (4) Separating means for separating high frequency components and low frequency components of the input luminance signal; a balanced modulator that balance-modulates a reference signal with the high-frequency component; a low-pass filter that obtains a lower band of the modulated output of the balanced modulator; and an output signal of the low-frequency component and the low-pass filter. a first adder that frequency-modulates the output of the first adder to obtain a frequency-modulated luminance signal; and a first frequency modulator that frequency-modulates the output of the first adder to obtain a frequency-modulated luminance signal; a second frequency modulator that obtains a frequency-modulated chrominance signal occupying a band lower than the band of the luminance signal; and a second adder that mixes the frequency-modulated luminance signal and the frequency-modulated chrominance signal to obtain a modulated color video signal. and means for recording the second adder output signal on a recording medium. (5) The first adder is configured to add the burst reference signal extracted from the reference signal for an arbitrary period of the blanking period of the input luminance signal, the low frequency component, and the output signal of the low pass filter. A video signal recording device according to claim 4. (6) Claim 4 or 5, characterized in that the input luminance signal is a luminance signal of the NTSC television system, and the frequency of the reference signal is the same as the color subcarrier frequency of the NTSC television system. The video signal recording device described in Section 1.