JPS63224578A - Rotary head type magnetic video recording and reproducing device - Google Patents

Abstract

PURPOSE:To contrive the improvement of the S/N of a color signal by recording a color signal by one head pair and using other head pair so as to record on a recording locus. CONSTITUTION:An NTSC signal inputted to a terminal 1 is separated into a luminance signal Y and a chrominance signal C by LPF2 and a BPF3. The separated signal Y is frequency-modulated by an FM modulator 4 and the signal C is converted into a prescribed low frequency by a balanced modulator 5. A synthesized signal via a mixer 6 at the normal state is fed to head pairs L', R' at the SP mode and head airs L, R at the EP mode via a recording amplifier 10 by a switch 9. In requiring the recording and reproducing characteristic of a more excellent chrominance signal, a changeover switch 7 is switched to the position of a contact (b) to turn on a switch, a low frequency conversion chrominance signal is fed to the head pairs R, L and an FM modulation luminance signal is fed to the head pairs R', L' by the switch 9. Thus, excellent color S/N is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a rotating head type magnetic recording and reproducing apparatus (hereinafter referred to as a VTR) using a helical scanning system, and is particularly characterized by a recording and reproducing system for color signals and luminance signals. It is something that you have.

BACKGROUND OF THE INVENTION In recent years, consumer VTRs such as VH8 system VTRs have been made capable of selectively switching between a standard recording mode (hereinafter referred to as SP mode) and a long recording mode (hereinafter referred to as EP mode) by switching the tape speed during recording. Recording and reproducing are performed by switching.

In order to obtain better recording and reproducing characteristics during recording and reproducing in SP mode and EP mode, a device is equipped with two pairs of heads: a magnetic head pair for SP mode and a magnetic head pair for EP mode. It is considered.

In addition, these two pairs of heads are sometimes arranged close to each other, as shown in Figure 3, in order to obtain better images during special playback such as still image playback and fast-forward playback. .

That is, in FIG. 4, Ll and R/ are the SP mode head pair, and L and R are the EP mode head pair whose head width is smaller than the SP mode head pair ' and R'. be. The interval between the two is set, for example, to the recording length of the video signal of two horizontal scanning periods (2H) on the magnetic tape.

Note that L and L' and R and R' have the same azimuth angle.

Furthermore, most recording systems for consumer VTRs, as shown in Figure 3, change the color signal C of the NTSC television signal to be recorded to a frequency lower than 3.58 MHz (for example, 629 KH).
A color low-frequency conversion method is used in which the signals are frequency-converted to z), mixed so as to be located in the low frequency range of the frequency-modulated luminance signal Y, and recorded using the same head.

Problems to be Solved by the Invention In the conventional color low-frequency conversion recording system, since the luminance signal Y and the color low-frequency conversion signal C are recorded and reproduced using one head,
In the recording amplifier, it is necessary to mix Y and C recording currents, and if care is not taken at the mixing ratio of Y and C, a phenomenon of cross modulation will occur, resulting in a screen that is very difficult to see. Furthermore, in order to prevent the above-mentioned cross-modulation, the C recording current value is set around -10 to -13 dB with respect to the optimal Y recording current.
This value is very low compared to the optimum recording current value at (KHz). Therefore, the color S/N is poor. Also, since Y and C are mixed on the recording amplifier, Y
Moiré in C and C is also a problem, and in order to prevent moire, the low range of Y is limited to prevent moiré, but this leads to a deterioration in resolution when recording and playing back. is the current situation.

In order to solve these problems, the present invention maintains the recording pattern recorded by the conventional method while making it reproducible.
The structure is such that when necessary, a recording pattern with improved color E37H and reduced moiré can be recorded.

Means for Solving the Problems In order to solve the above-mentioned problems, the rotary head type magnetic recording/reproducing apparatus of the present invention has a pair of first and second heads so as to correspond to recording and reproduction at mutually different tape speeds. It is placed on a rotating cylinder and generates a composite signal that is a mixture of a color signal frequency-converted to a low frequency band and a luminance signal located in a higher frequency band than the color signal in the low frequency band, depending on the selected tape speed. , a first recording and reproducing mode in which the first and second head pairs are selected and sequentially recorded and reproduced on the magnetic tape;
The color signal in the low frequency band is recorded by the first pair of heads, and the luminance signal located in the high frequency band is scanned by the second pair of heads on the recording locus of the color signal by the first pair of heads, The second one records and plays back on magnetic tape.
The recording/playback mode can be selected.

Operation According to the above configuration, normally the SP mode or EP mode is selected as in the past to operate as a color low frequency conversion recording method, and when necessary, low frequency conversion is performed by one head pair among a plurality of head sets. By recording the converted color signal and recording the brightness signal in the high frequency band using another pair of heads from above the recording trajectory, it becomes possible to record the color signal and brightness signal separately and overlappingly on the tape. Compared to the conventional method of recording a composite signal of a low-frequency converted color signal and a luminance signal during recording, both the color signal and the luminance signal can be set to a more optimal recording current value, and the S/N of the color signal is improved. This will improve the results.

Example Examples thereof will be described below with reference to the drawings.

In FIG. 1, 1 is an input terminal to which an NTSC signal to be recorded is applied;
The SC signal is separated into a luminance signal component Y and a color signal component C by the LPF2 and BPF3, respectively. The separated luminance signal Y is frequency-modulated by the FMM modulator 4, and the color signal is modulated by the balanced modulator 6 to a predetermined low frequency (for example, VH
8 system, the frequency is converted to 629 KHz).

During normal recording, this FM volatile signal and low frequency conversion color signal are mixed by the mixer 6, and this mixed composite signal is sent to the head via the recording amplifier 10 by the switch 9. , H/, and EP are applied to the head at one time to record on the magnetic tape.

The above operation is the same as the recording method in VHS system or β system VTR. A feature of this embodiment is that a changeover switch 7 and a switch 8 are further provided.

That is, when better recording and reproducing characteristics of color signals are required, the changeover switch 7 is switched to the contact side, the switch 8 is turned on, and the low frequency converted color signal is sent to the heads R and L via the recording amplifier 11. The FM modulated luminance signal is applied to the head pair R', L' by the switch 9.

According to this configuration, as shown in FIG. 2, the color signals are superimposed on the recording trajectory CR2CL recorded by the heads R and L).
The FM luminance signal from Sodoptt and Lt is the recording trajectory YR'
, YL'. At this time, since the low frequency converted color signal has a lower frequency than the frequency-modulated luminance signal component, it is recorded deep in the thickness direction of the magnetic tape, and the luminance signal is recorded above it. Even during playback,
A color signal is reproduced from the reproduced signals from the head pair R, L, and a luminance signal is reproduced from the head pair R/, L/.

Effects of the Invention As described above, according to the present invention, it is possible to record and reproduce color television signals with better color S/N characteristics when necessary by making only slight improvements to conventional VTRs. . Furthermore, it is possible to record and reproduce data using conventional methods, and to maintain compatibility.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the rotary head type magnetic recording/reproducing device of the present invention, FIG. 2 is a diagram schematically showing the recording locus of the same embodiment, and FIG. 3 is a diagram showing a low frequency conversion recording method. FIG. 4, a spectrum diagram of a recording signal, is a diagram showing the head position on a rotating cylinder of a conventional rotating head type magnetic recording/reproducing device. 2...LPF, 3...BPF, 4...
...FM modulator, 6...Balanced modulator, 6.
...Mixer, 10, 11... Recording amplifier, L, R, L/, R/... Magnetic head. Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] A pair of first and second heads are arranged on a rotating cylinder to correspond to recording/reproducing at mutually different tape speeds, and a color signal frequency-converted to a low frequency band is located in a higher frequency band than the color signal in the low frequency band. a first recording and reproducing mode in which the first and second head pairs are selected to sequentially record and reproduce a composite signal mixed with a luminance signal on the magnetic tape according to a selected tape speed; A color signal in a frequency band is recorded by the first pair of heads, and a luminance signal located in the high frequency band is recorded by a second pair of heads that scans a recording locus of the color signal by the first pair of heads. A rotary head type magnetic recording and reproducing device that can select a second recording and reproducing mode for recording and reproducing on a magnetic tape.