JPH04172097A - Magnetic recording/reproducing method for color video signal - Google Patents

Abstract

PURPOSE:To record an ultra-fine color video signal on a magnetic tape by varying the time base compressibility according to the content of the inputted video signal. CONSTITUTION:A brightness signal and a color difference signal inputted from input terminals 1-3 are converted into a digital signal then compressed and expanded at a time base, and stored in the memory of a recording side video signal processing circuit 6 temporarily. And as a signal process converting the brightness signal component and the color signal component of the input color video signal into a one channel time base compression multiplex signal, while the continuous signal of the brightness signal component and the color signal component of a one horizontal synchronizing period is converted into the time base compressing/expanding signal of an always fixed time length according to the content of information included in each signal respective time base compressing/expanding ratios are varied adaptedly. Thus, it is possible to record the ultra-fine color video signal on the magnetic tape.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for magnetically recording and reproducing color video signals, such as in a video tape recorder, which records and reproduces high-quality color video signals and audio signals using magnetic tape. .

2. Description of the Related Art Conventional analog VTRs for recording and reproducing component color video signals record color video signals on a magnetic tape by compressing and expanding the luminance signal and color signal on the time axis.

Problems to be Solved by the Invention In conventional analog VTRs that record and play back component color video signals, the time axis compression/expansion ratios of luminance signals and color signals are constant depending on the format, resulting in extremely high definition. The drawback is that the resolution does not particularly increase when a video signal is input.

Means for Solving the Problems In order to solve the above problems, in the present invention, the time axis compression ratio of the video signal is changed depending on the content of the input video signal, and an ultra-high definition color video signal is recorded on a magnetic tape. to be recorded.

Function The present invention can record ultra-high definition color video signals on a magnetic tape with the above-described configuration.

EXAMPLE An example of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of main parts in one embodiment of the present invention. Specifically, it is assumed that the color video signals to be recorded in this embodiment are a luminance signal Y and two color difference signals Cw and Cn that constitute a no-vision signal. In FIG. 1, for example, a luminance signal is input to input terminal 1.
The color difference signal CW is input to the input terminal 2, and the color difference signal Cn is input to the input terminal 3. The luminance signal inputted from the input terminal 1 is inputted to the synchronization separation circuit 4, where it is separated into a horizontal synchronization signal and a vertical synchronization signal. The separated horizontal synchronization signal and vertical synchronization signal are input to the recording side reference clock generation circuit 6. The recording-side reference clock generation circuit 6 utilizes a well-known PLL circuit to determine the time axis reference for the operation of each circuit's one-rotation cylinder, capstan motor, etc. during recording from a horizontal synchronization signal and a vertical synchronization signal. A reference clock is generated.

Now, the luminance signals 9 and the color difference signals Cw and Cw inputted to the input terminals 1, 2, and 3 are led to the recording side video signal processing circuit 6, and after being converted into digital signals, they are converted into digital signals as well known in the art. Time axis compression and expansion are performed, and the data is then stored in the memory within the recording side video signal processing circuit 6. Then, as a signal/process to convert the luminance signal component and chrominance signal component of the input color video signal into a time axis compression multiplexed signal of 1 channel μ, the luminance signal for one horizontal synchronization period is converted according to the information contained in each signal. The continuous signals of the color signal component and the color signal component are always converted into time-domain compression/expansion signals having a constant time length, and the respective time-domain compression/expansion rates are adaptively changed. That is, if the input luminance signal is of high definition and the color signal is not of high definition, the TCI sampling frequency of the luminance signal is increased and the TCI sampling frequency of the chrominance signal is decreased. Conversely, if the input luminance signal does not have high definition but the chrominance signal has high definition, the TCI sampling frequency of the luminance signal is lowered and the TCI sampling frequency of the chrominance signal is increased. It is well known that statistically in color video signals, if the luminance signal is high definition, the color signal is not high definition, and if the luminance signal is not high definition, the chrominance signal is often high definition. There is.

Therefore, although the image quality during playback may be improved by changing the sampling frequency, it will not be reduced.

By the way, in this embodiment, as shown in FIG. 1, two magnetic helads 8 and 9 are mounted on a rotating cylinder 11 that rotates in a direction 12. However, the two magnetic helads 8 and 9 are arranged symmetrically about the center of rotation. Here, the track widths of these two magnetic heads are all the same, and the azimuths are opposite to each other. Moreover, the magnetic tape 1o is placed on the rotating cylinder 11 by approximately 1
The magnetic tape 10 is wound at an angle of 80 degrees or more, and at least one magnetic head is always in contact with the magnetic tape 10.

In this embodiment, as shown in FIG.
A channel time axis compression/expansion signal (TCI signal) is supplied to one specific magnetic head in contact with the magnetic tape 1o, and the magnetic head receives the magnetic tape 1o.
A signal is recorded on o. One point of the present invention lies in the recording track pattern of the recorded signal. That is, in the present invention, since time-axis expanded or compressed video signals, whether luminance signals or color signals, are frequency modulated (FM modulated) and recorded, the signals recorded on adjacent tracks are statistically If a signal with a strong correlation is selected, even if the crosstalk signal recorded on this adjacent track is picked up during playback, the so-called 3
According to the theory of angular noise, this crosstalk signal is sufficiently attenuated so that the crosstalk disturbance to the reproduced image quality is not noticeable. In other words, the track pattern is such that signals with strong correlation between adjacent tracks are recorded.
The recording side video signal processing circuit 6 transmits its output to the FM modulation circuit 7 based on the time reference signal of the recording reference clock generation circuit 6 which also controls the rotational phase of the rotary cylinder 11. The output of the FM modulation circuit 7 is supplied to the magnetic head and written on the magnetic tape 10.

In this embodiment, the video signal is compressed on the time axis after removing the vertical synchronization signal, so the recording length of the video signal recording track corresponds to the period during which the magnetic head rotates 180 degrees on the rotating cylinder. The length is shorter than the length, i.e. about 16
It will be 6 degrees. As a result, the recording area has a margin of about 16 degrees, and can record PCM audio signals and the like.

With simple control of the recording timing, the video signal is recorded in the opposite azimuth on the track adjacent to the part where the video signal is recorded, and the video signal is recorded in the opposite azimuth on the track adjacent to the part where the audio signal is recorded. It can be made into a track pattern where the audio signal is recorded.

In addition, the length of the video signal recording track is equivalent to the period during which the magnetic head rotates 170 degrees on the rotating cylinder, and the PCM audio signal recording track is continuous with the track on which the video signal is recorded. area, and its recording track length is 2
It is also conceivable that the magnetic tape is wound around the rotary cylinder at an angle of 180 degrees and 10 degrees as the length corresponding to the period of 0 degree rotation. An example of the recorded TCI signal is
As shown in the figure. 4 Now,
During playback, the original signal is restored using the reverse process of recording. In FIG. 1, the signal reproduced from the magnetic head is input to the reproduction side reference clock generation circuit 13, where:
The timing at which a specific video signal or audio signal is recorded is detected by detecting a synchronization signal or a burst signal.

The reproduction side video signal processing circuit 16 performs signal processing opposite to that on the recording side, and outputs a luminance signal from the output terminal 16, a color difference signal Cw from the output terminal 17, and a color difference signal Cw from the output terminal 18 as reproduction signals.
A color difference signal Cn is outputted from each of the two.

In this embodiment, the case where the recording TCI signal has one channel has been described, but it is also possible to realize, for example, the case of two channels, three channels, or, generally, the case of N channels, where N is a positive integer.

Effects of the Invention According to the present invention, it is possible to record ultra-high definition color video signals on a magnetic tape while keeping the number of recording channels of a VTR unchanged.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a main part in an embodiment of the present invention, and FIG. 2 is a pattern diagram showing an example of a recording signal subjected to time axis compression/expansion according to the present invention. 6... Recording side video signal processing circuit, 16...
...Playback side video signal processing circuit.

Claims (5)

[Claims] (1) Signal processing that inputs a color video signal and converts the luminance signal component and chrominance signal component of the color video signal into a one-channel time-base compression multiplexed signal. The continuous signals of the luminance signal component and the chrominance signal component during the horizontal synchronization period are always converted into time-domain compression/expansion signals with a constant time length, and the time-domain compression/expansion rate of each is adaptively changed. A method for magnetically recording and reproducing a color video signal, which comprises recording an axial compression/expansion signal on a magnetic tape. (2) The color video signal according to claim 1, wherein the signal form when the color video signal is recorded is a time axis compression/expansion signal of a frequency-modulated luminance signal and two color signals. Magnetic recording and reproducing method. (3) The color video signal according to claim 1, wherein the signal form when the color video signal is recorded is a time-base compression/expansion signal of a frequency-modulated luminance signal and a line-sequential color difference signal. Magnetic recording and reproducing method. (4) The recording track pattern is determined so that the frequency-modulated luminance signal and the two color difference signals recorded on the magnetic tape have a statistically high correlation with the signals recorded on adjacent tracks. 4. A method for magnetic recording and reproducing a color video signal according to claim 2 or 3, characterized in that: (5) Signal processing that inputs a color video signal and converts the luminance signal component and chrominance signal component of the color video signal into an N-channel time-base compression multiplexed signal, where N is an integer, is performed on information contained in each signal. Depending on the content, the sum signal of the luminance signal component and the chrominance signal component in one horizontal synchronization period is always converted into a time-domain compression/expansion signal with a constant time length, while the respective time-domain compression/expansion rates are adaptively changed. A method for magnetically recording and reproducing a color video signal, which comprises recording an N-channel time-base compression/expansion signal on a magnetic tape.