JPH05207508A - Recorder for color video signal - Google Patents

Abstract

PURPOSE:To record a color video signal at a base band properly in response to an aspect ratio of a displayed pattern. CONSTITUTION:A luminance signal Y and color difference signals R-Y, B-Y are time-compressed for each unit time. The luminance signal Y and color difference signals R-Y, B-Y time-compressed are subjected to time division multiplex within a prescribed time and the result is recorded on a recording medium. Sampling clocks CKy, CKc of the luminance signal Y and color difference signals R-Y, B-Y are selected depending on the aspect ratio of the displayed pattern which is 16:9 or 4:3, and the share rate of the luminance signal Y and difference signals R-Y, B-Y for a prescribed time for time division multiplex is changed depending on the aspect ratio.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image signal recording apparatus for time-compressing a luminance signal and a chrominance signal and performing base-band recording as a time division multiplexed signal.

[0002]

2. Description of the Related Art When a color image signal is recorded by forming an oblique track on a magnetic tape as a baseband signal of a luminance signal Y and color difference signals RY and BY of red and blue, the luminance signal and A recording method called a TCI method for recording a color difference signal as a time division multiplexed signal is known.

In this recording method, as shown in FIG. 3, a luminance signal Y (FIG. 3A), a red color difference signal RY (FIG. 3B), and a blue color difference signal B are provided for each horizontal section. -Y (FIG. 3C) are time-compressed, and the time-compressed signals are distributed in one horizontal section, for example, so that the distribution ratio is Y: RY-BY: RY = Ry: Rc: Rc. , Time division multiplexing.

In this case, the total number of samples per horizontal section, which is the unit period of the time division multiplexed signal, is determined according to the transmission rate. Therefore, the luminance signal and the color difference signal which are time division multiplexed per horizontal section. The number of samples is determined according to the distribution rate.

[0005]

By the way, when the aspect ratio of the display screen, that is, the aspect ratio of 16: 9 is long like the high definition television signal, the display screen of the current standard television system is used. It is desirable that the resolution in the horizontal direction be higher than that of the aspect ratio of 4: 3. For this purpose, it is better to increase the distribution rate of the time division multiplexing of the luminance signal.

However, in such a case, in the case of the current aspect ratio of 4: 3, the horizontal resolution becomes excessively high, but on the other hand, there is a drawback that the color resolution becomes poor.

An object of the present invention is to provide a color video signal recording apparatus capable of obtaining an optimum reproduced color image corresponding to two kinds of aspect ratios.

[0008]

In order to solve the above-mentioned problems, a color video signal recording apparatus according to the present invention time-compresses a luminance signal and a color signal for each unit of time, and a time-compressed luminance signal and color signal. In a device for time-division-multiplexing a signal within a predetermined time and recording it on a recording medium, a luminance signal within the predetermined time for time-division multiplexing when the aspect ratio of the display screen is 16: 9 and 4: 3 And a color signal distribution ratio changing means is provided.

[0009]

According to the aspect ratio of the color video signal to be recorded, the distribution ratio of the time division multiplexing of the luminance signal and the color difference signal is changed and recorded.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a color video signal recording apparatus according to the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of the main part of the recording apparatus of this example. Luminance signal Y through the input terminals 1, 2 and 3,
The red color difference signal RY and the blue color difference signal BY are supplied to the clamp circuits 4, 5, and 6, respectively.

The luminance signal Y from the input terminal 1 is also
The horizontal sync signal HD is supplied to the horizontal sync separation circuit 22, and the horizontal sync signal HD is obtained. The horizontal sync signal HD is supplied to the clamp pulse generation circuit 23, and the clamp pulse is obtained therefrom. Then, the clamp pulse is supplied to the clamp circuits 4, 5 and 6, respectively, and in the clamp circuits 4, 5 and 6, the luminance signal Y and the red color difference signal R are supplied.
The −Y and blue color difference signals B−Y are, for example, pedestal clamped.

The luminance signal Y from the clamp circuit 4 is A /
It is supplied to the D converter 7 and is sampled by the sampling clock CKy having a frequency corresponding to the distribution rate of the time division multiplexing of the luminance signal Y, and the sampling value is converted into a digital value.

Similarly, the red and blue color difference signals R-Y and B-Y from the clamp circuits 5 and 6 are supplied to the A / D converters 8 and 9 to be distributed to the time-division multiplex of the color difference signals. Sampling is performed by the sampling clock CKc having a corresponding frequency, and the sampled values are converted into digital values.

The digital luminance signal from the A / D converter 7 is passed through the delay circuit 10 for multiplexing after the color difference signal in the time division multiplexing, one horizontal interval at a time, and a line memory for time compression processing. 11 is supplied. Also, A
The digital color difference signals from the / D converters 8 and 9 are also
Further, it is supplied to the line memories 12 and 13 for time compression processing for each data amount of one horizontal section same as the luminance signal.

In the line memories 11, 12, and 13, time compression is performed according to the ratio of the read speed and the write speed. The time compression rate is determined by the distribution rate of the luminance signal and the color difference signal in one horizontal section which is a unit section of time division multiplexing.

The line memories 11, 12, 1
The time-compressed digital luminance signal and digital color-difference signal from 3 are supplied to the switch circuit 14, and the switch circuit 14 is switched by the timing signal MT for time division multiplexing, so that the red color-difference signal R-Y and the blue color difference signal. The color difference signal BY and the luminance signal Y are time-division multiplexed in one horizontal section. In this case, although not shown, the digital data from the line memories 11, 12, and 13 are read in synchronization with the switching timing of the switch circuit 14. The read clock is also the same clock in the line memories 11 to 13, and is switched to the line memories 11 to 13 in synchronization with the timing signal MT.

The time-division multiplexed signal from the switch circuit 14 is supplied to the field memory 15 to remove unnecessary horizontal sections of the vertical blanking section to convert the number of lines per field, and within the one-field section. Shuffling processing for rearranging the data in units of one line is performed according to a predetermined rule.

The signal from the field memory 15 is
The signal is supplied to the adder circuit 16, and the synchronizing signal SYNC and the burst signal SB from the synchronizing / burst signal generating circuit 17 are added to this signal. The synchronization signal SYNC and the burst signal SB are formed as time division signals to be recorded.

The output signal of the adder circuit 16 is supplied to the D / A converter 18 and returned to an analog signal. Then, the analog time division multiplexed signal from the D / A converter 18 is supplied to the modulation circuit 20 via the emphasis circuit 19 and frequency-modulated. The output signal of the frequency modulation circuit 20 is supplied to a recording amplifier 21 and recorded as a diagonal track on a magnetic tape by a recording rotary head (not shown).

In this case, the frequency of the sampling clocks CKy and CKc used in the A / D converters 7, 8 and 9 is 16: 9 for the aspect ratio of the color video signal to be recorded.
For example, a high-definition signal or an aspect ratio of 4:
It is adapted to be switched depending on whether it is the current signal of No. 3.

That is, 30 is a sampling clock generation circuit. Reference numeral 31 is a variable frequency oscillator from which an oscillation output signal having a center frequency of 12 fsc (fsc is a color subcarrier frequency) is obtained. The output signal of the variable frequency oscillator 31 is frequency-divided into a horizontal frequency signal by the frequency dividing circuit 32 and then supplied to the phase comparison circuit 33. The phase comparison circuit 33 is supplied with the horizontal synchronization signal HD from the horizontal synchronization separation circuit 22 and is compared in phase with the signal from the frequency dividing circuit 32. Then, the phase comparison error output from the phase comparison circuit 33 is supplied to the variable frequency oscillator 31, and the oscillation output signal is controlled so as to be phase-synchronized with the horizontal synchronization signal HD.

Then, the oscillation output signal of the variable frequency oscillator 31 is supplied to the frequency dividing circuit 34 and frequency-divided by 1/3, and the frequency dividing circuit 34 obtains a clock having a frequency of 4 fsc. The output clock of the frequency dividing circuit 34 is supplied to the switch circuit 38 and also to the frequency dividing circuit 35, and is further divided by 1/2, and the frequency dividing circuit 35 obtains a clock having a frequency of 2 fsc.

The output signal of the variable frequency oscillator 31 is also supplied to the frequency dividing circuit 36 and frequency-divided by 1/2, and a clock having a frequency of 6 fsc is obtained from the frequency dividing circuit 36. The output clock of the frequency divider circuit 36 is the switch circuit 3
A clock having a frequency of 1.5 fsc is obtained from the frequency dividing circuit 37 while being supplied to the frequency dividing circuit 37 and the frequency dividing circuit 37.

The clocks from the frequency dividing circuits 34 and 35 are
Clocks CKy and CK when the aspect ratio is 4: 3
c. The clocks from the frequency dividing circuits 36 and 37 are the clocks CKy and CKc when the aspect ratio is 16: 9.

That is, the switch circuit 38 is switched according to the aspect ratio of the color video signal to be recorded by the switching signal SW. When the color video signal to be recorded has an aspect ratio of 16: 9, the input of FIG. Edge W
State, that is, the sampling clock C of the luminance signal Y
The output of the frequency dividing circuit 36 is obtained as Ky, and the color difference signal R-
The Y and B-Y sampling clocks CKc are switched to a state in which the output of the frequency dividing circuit 37 can be obtained. As a result, when the aspect ratio is 16: 9, the adding circuit 15
2A, the distribution rate per horizontal section is Y: RY-BY: BY = 6fsc: 1.5fsc: 1.5fsc = 4: 1: 1 as shown in FIG. 2A. You get what was done. Note that, in FIG. 2, the numerical values indicate the number of samples in the corresponding period.

Next, when the color video signal to be recorded has an aspect ratio of 4: 3, the switch circuit 38 is in the state of the input terminal N of FIG. 1, that is, the output of the frequency dividing circuit 34 as the sampling clock CKy of the luminance signal Y. Is obtained, and the state is switched to a state in which the output of the frequency dividing circuit 35 is obtained as the sampling clock CKc of the color difference signals RY and BY. As a result, when the aspect ratio is 16: 9, D /
As the time division signal from the A converter 18, as shown in FIG. 2B, the distribution rate per horizontal section is Y: RY: BY = 4fsc: 2fsc: 2fsc = 4: 2: 2. You can get what you want.

As described above, in this example, when the aspect ratio is 16: 9, the color image signal is recorded such that the luminance signal has a wider band than that when the aspect ratio is 4: 3, and When the aspect ratio is 4: 3, the color video signal is recorded in a state where the band of the luminance signal is not excessively widened and the band of the color difference signal is widened.

In the above example, the color video signal is recorded on the tape in an analog signal state.
It goes without saying that the present invention can also be applied to recording in the state of digital signals.

Further, the distribution ratio of the luminance signal and the color signal as a time division signal is not limited to the value described in the above example, and it goes without saying that various values can be selected.

[0031]

As described above, according to the present invention, when the aspect ratio of the display screen of the color video signal to be recorded is 16: 9, the luminance signal is relatively wide band, and when it is 4: 3, the color signal is color. Since the signal is made to have a relatively wide band, the luminance signal as a time division signal is recorded by switching the distribution ratio with the color signal according to the aspect ratio, so that recording can be performed effectively using a constant recording band. A device can be provided.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of a color video signal recording apparatus according to the present invention.

FIG. 2 is a waveform diagram of a recording signal according to an aspect ratio.

FIG. 3 is a diagram for explaining a time division signal to be recorded.

[Explanation of symbols]

 1 Input terminal of luminance signal Y 2 Input terminal of color difference signal RY 3 Input terminal of color difference signal BY 7 A / D converter of luminance signal Y 8 A / D converter of color difference signal RY 9 Color difference signal B- Y A / D converter 11 Time compression line memory for luminance signal Y 12 Time compression line memory for color difference signal RY 13 Time compression line memory for color difference signal BY 14 Switch circuit for generating time division signal 30 Sampling clock generation circuit CKy Luminance signal sampling clock CKc Color difference signal sampling clock

Claims (1)

[Claims] 1. An apparatus for time-compressing a luminance signal and a chrominance signal for each unit of time and recording the time-compressed luminance signal and chrominance signal on a recording medium by time-division multiplexing in a predetermined time. A color video signal is provided with means for changing the distribution ratio of the luminance signal and the color signal within the predetermined time of the time division multiplexing depending on the aspect ratio of 16: 9 and 4: 3. Recording device.