JPH03108985A - Magnetic recording and reproducing device for high fidelity color video signal - Google Patents

Abstract

PURPOSE:To prevent picture quality from being degraded by the cross talk interference, etc., of an adjacent track by dividing a high fidelity base band signal into the signals of (n) channels and executing recording/reproducing by using the 2n-pieces of specified magnetic heads. CONSTITUTION:In a signal processing circuit 4 to divide the high fidelity base band signal into the recording signals of the (n) channels, memories for the (n) channels are provided to record the high fidelity base band signals within a period more than one field period. Then, the 2n-pieces of the magnetic heads forming the (n)-pieces of pairs are provided to be arranged on a rotary cylinder 8, which is rotated by (n+1)/n in one field, symmetrically at 360/2n deg., and to these magnetic heads, the recording signals of the (n) channels are supplied. The recording signals of the (n) channels are respectively supplied to the (n)- pairs of the magnetic heads, which are made symmetric for each channel, and the signals are recorded and reproduced onto a magnetic recording medium 10. Thus, the picture quality can be prevented from being degraded by the cross talk interference, etc., of the adjacent track.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a high-definition color video signal recording and reproducing apparatus such as a home-use vision VTR that records and reproduces high-definition color video signals on a magnetic tape.

Conventional technology Previous attempts at recording and reproducing high-definition video signals for the purpose of applying them to home VTRs were made by the Japan Broadcasting Corporation (NHK).
Studies have been conducted on recording and reproducing in the form of a MUSE signal, which is a band-compressed signal of a non-visible eye signal, as proposed by . For example, the Proceedings of the 1987 National Conference of the Television Society, Volume 7-16, the Recording Study Group of the Television Society,
This is a recording method as shown in VRsa-4゜Page 19-24, January 27, 1986.

Problems to be Solved by the Invention In VTRs that record and play back these MUSE signals, a complex algorithm and a relatively large scale are required to convert the MUSE signal, which is an analog Φ sample μ value, into a high-definition e baseband signal. This method requires a signal processing circuit, which makes it difficult to apply it to a camera-integrated VTR, and there is also the problem of leakage. Furthermore, if solid recording without guard bands is performed in a VTR that records and reproduces MUSE signals, there is a drawback that the image quality deteriorates greatly as motion detection errors occur due to crosstalk interference between adjacent tracks.

In view of the above-mentioned problems, the present invention records and reproduces a high-definition baseband signal, which is a high-quality video signal, by dividing it into 2-channel signals, and uses 2n magnetic heads, for example, 4 magnetic heads. With an extremely simple configuration,
It can be easily applied to camera-integrated VTRs, etc., and the azimuth recording eliminates guard bands, resulting in high recording density and long recording and playback times.
Since the recording track/notations of the two magnetic heads are symmetrical, the four magnetic heads can be used not only in the standard mode but also in the long-term mode, and there is no need to add four new magnetic heads. The present invention provides a high-quality color and video signal magnetic recording and reproducing device that has excellent features and is easy to deploy for home use.

Means for Solving the Problems In order to solve the above problems, in the present invention, a signal processing circuit that divides a high-definition φ baseband signal into n-channel recording signals is provided with It is equipped with n channels of memory for storing vision-based signals, and one field (
360/2 on a rotating cylinder that rotates n+1)/n
Equipped with 2n magnetic heads forming n pairs arranged n degrees symmetrically and supplied with n channels of recording signals,
Furthermore, it is constructed with a capstan φ motor φ drive circuit that changes the magnetic tape feeding speed between a standard mode and a long time mode.

Effect of the Invention The present invention has the above-mentioned configuration, which realizes high-density recording without a guard band even though it is a VTR that records and plays back a no-vision baseband, and is capable of long-time recording suitable for home use. Despite recording and reproducing high-visibility signals with a large amount of information, the relative speed of the heads during the tape is relatively small, and since there are only four magnetic heads used, the mechanical rotation of the rotating cylinder requires precision. While making it possible to realize a VTR with an extremely simple configuration both in terms of circuitry and circuitry, it is also possible to realize a VTR that has two or more types of recording and playback time for the same tape, such as standard mode and long time mode. shall be.

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. For example, in Figure 1, input terminals 1, 2, and 3 are connected to Figure 2 (1) # @ and (2), respectively.
Hi-Vigilance baseband luminance signal Y as shown in
and two color difference signals CW and CN are input. Here Y
, CW and CN are 20 MHz and 7 MHz, respectively
z and 5.5 MHz, one frame has two fields and 1126 lines.

These three Y's.

The Cw and CN signals reach the recording side video signal processing circuit 4. The video signal processing circuit on the recording side has a configuration as shown in FIG. . and vertical synchronization signal V, an
. The signals are separated and each input to a control circuit 20 formed by a microcomputer. In the control circuit 20, three A
/D converters A/D21, A/D22 and A/D converters
Generates the A/D conversion clock for D23. Y is A/D converted to abit by A/D converters 21, 22 and 23.

Cw and CN are respectively recorded in the memory 24 and the memory 26 in the order of line numbers, with the sear address and write timing controlled by the control circuit. Here memory 2
The format in which y, cw, and CN are written to the memory 26 is such that odd lines are written to the memory 24 and even lines to the memory 26. The Y, Cw and CN signals written to the memory are shown in Figure 2 (4).
And as shown in ■, the time axis converted form of n channels A/A and B is stored in the memory 24 in the order of Y, cw and CN.
and two D/A converters 26
and 27 are converted into analog signals, which are input to the FM modulators 6 and 7 in FIG. 1, where they are FM modulated and then recorded and amplified to become recording signals A and B. However, the bands of Y, Cw, and CN that have been time-axis transformed in A and B are the same. The n-channel recording signals A and B are recorded on a rotary cylinder 8 with four
The four magnetic heads A←), B(→, C(→ and D(→) are formed.However, these four heads form a bare head with the same azimuth angle when they are located symmetrically with respect to the center of the rotating cylinder. Assume that the adjacent heads on the circumference of the cylinder have an opposite azimuth relationship.The rotating cylinder rotates in the direction of arrow 9, and there are approximately 180
A magnetic tape 10 is wound over the length of 0. This magnetic tape 1° is moved in the direction of arrow 12 by a capstan motor 11. Here, the rotational phases of the rotary cylinder 8 and the capstan motor 11 are controlled by commands from a rotation control circuit 6 which changes the rotation mode in response to a mode switching signal input from the outside. The rotation of the rotating cylinder 8 is controlled so that it rotates once during one field period of the input visual baseband signal. The rotation of the capstan motor is controlled so that the recording track width on the tape is approximately equal to the head width, or approximately half the head width. Input Y in Figure 4 (1) # @ and (3).

Frequency Spectrum of Cw and CN Signals) /1/ and ) show the frequency spectrum of the recording baseband signal A@ divided into n channels. For example, in the FM modulators 6 and 7, the sync chip frequency is 1yM as shown in the fourth drawing.
Hz, 10 oz.6 of white is FM modulated to 20 MHz. For example, if the rotating cylinder of a VH8 type VTR rotates eO0 times per second, the relative speed will be approximately 11.6 m/SeC, but sufficient recording and reproduction is possible using a high-performance metal head and metal tape. FIG. 6 shows a recording track pattern recorded by four magnetic heads.

In Figure 6, the neighbor of Y is Y, and the neighbor of Cw is Cw.
Since the neighbor of CN is CN, crosstalk interference after 91M demodulation is reduced due to the correlation of the video signal even in solid writing recording. In the present invention, since the four magnetic heads on the rotating cylinder are arranged 900 degrees symmetrically, the recording track patterns of the four magnetic heads are all symmetrical even if the tape feed speed changes, for example. Therefore, even if the tape feeding speed changes, the track pattern does not change, so the same magnetic head used in the standard mode can be used in the long time mode.

Now, in the standard mode and the long time mode, the signals recorded as shown in FIGS. 6 and 6, respectively, are reproduced by the same magnetic head as when they were recorded. In FIG. 1, magnetic head A(→, A(→, B)
(→ and B(→), the n-channel signals ARP' and BRF' reproduced by the two magnetic heads that are always in contact with the magnetic tape 1o are sent to the FM demodulator 13, respectively.
and 14, is reproduced and amplified, then FM demodulated, and then inputted to the reproduction side signal processing circuit 15. The reproduction side signal processing circuit 15 performs the reverse processing to that performed in the recording side signal processing circuit 4 (see FIG. 2), and produces a reproduction signal Y' of the three-channel high-vigilance baseband signal.
, Cw' and CH2 are obtained. Y/.

Cw' and CH2 are output from output terminals 16, 17 and 18, respectively.

By the way, if four magnetic heads are installed in a conventional n-channel/I/VTR such as Ml-format or β-CAM, two of which are arranged close to each other on a rotating cylinder, Since the same track pattern cannot be obtained in the long-duration mode and the standard mode, recording and reproduction are impossible.

Further, the present invention is applied to various video signal recording apparatuses in which an electromagnetic conversion system is capable of two-channel recording.

That is, the input signals to the circuit system are R signal and G signal.

Whether it is a 3-channel signal such as a B signal, a 1-channel signal, an n-channel signal, or a 3.4-channel signal, it is sufficient to convert it into an n-channel signal and record it. Furthermore, the recording track pattern on the magnetic tape is not limited to the diagram shown in FIG. A similar effect can be obtained even if signal processing is performed so that a color signal is recorded adjacent to two color signals.

Furthermore, although the present embodiment has been described for the case of 4 heads, similar effects can be obtained when N is 6 heads, or when N is an integer larger than 3 and 2N heads are used.

Effects of the Invention In conventional VTRs that record and play back MUSE signals, there is noise at the corners due to time axis errors, and in solid recording, crosstalk between adjacent tracks can greatly improve image quality, such as mistakes between video mode and still image mode. There is a problem of deterioration. Furthermore, it is difficult to apply this technology to circuit-scale camera-integrated VTRs.

However, as shown in the present invention, the shape of the running track of the magnetic head can be made similar in both the standard mode and the long-time mode, so high-visibility run can be achieved with as few as four magnetic heads in multiple recording and reproducing modes. Recording and reproduction of baseband signals becomes possible. Furthermore, since it handles baseband signals, it is easy to develop into a camera-integrated VTR.

FIG. 5 is a recording track pattern diagram according to the present invention.

1.2, 3... Input terminal, 4... Recording side signal processing circuit, 5... Rotation control circuit, 6, 7
...FM modulator, 8...Rotating cylinder, 9...Rotation direction of rotating cylinder, 10...
. . . Magnetic tape, 11 . . . Capstan motor, 12 . . . Moving direction of magnetic tape, 13.
14...FM demodulator, 15...Playback side video signal processing circuit, 16, 17.18...Output terminal, 19...Synchronization signal separation circuit , 20...
...Control circuit, 21.22.23...A/D
Converter, 24°26...Memory, 26,27.
...D/A converter.

Claims (3)

[Claims] (1) A means for converting an input high-definition color video signal into an n-channel recording signal, and a rotating cylinder (n+1)/n for each field of the high-definition color video signal.
A high-quality color video signal magnetic recording and reproducing device comprising a rotating cylinder drive circuit for rotating, and 2n magnetic heads arranged on the rotating cylinder symmetrically by (360/2n) degrees with respect to the rotation center, The n-channel recording signals are supplied channel by channel to n sets of magnetic head bears that are symmetrical (360/n) degrees with respect to the rotation center of the rotary cylinder among the 2n magnetic heads. A high-quality color video signal magnetic recording and reproducing device characterized in that it is configured to record and reproduce channel recording signals on a magnetic recording medium. (2) means for converting an input high-quality color video signal into a two-channel video signal of a luminance signal and a color signal;
means for time-axis expanding the luminance signal and time-axis compressing the color signal; and channel switching of the time-axis expanded luminance signal and the time-axis compressed chrominance signal every M lines (M is an integer greater than 1). A high-quality color video signal magnetic recording and reproducing apparatus according to claim 1, further comprising means for recording and reproducing high-quality color video signals. (3) Claim 1, further comprising a drive circuit that changes the feeding speed of the magnetic recording medium for each of a plurality of modes, and changes the recording track width by the four magnetic heads for each of the plurality of modes. ) or (2). (4) A means for converting an input high-quality color video signal into an n (an integer of n≧3) channel recording signal, and a rotary cylinder drive circuit that rotates the rotary cylinder once for each field of the color video signal. and n magnetic heads attached to the rotary cylinder symmetrically by (180/n) degrees with respect to the rotation center thereof, and one channel of the recording signal of the n channels is attached to the rotary cylinder among the 2n magnetic heads. and a means for supplying each of the n sets of magnetic head bearings 180 degrees symmetrical with respect to the center of rotation of the high-speed recording medium, and recording and reproducing the n-channel recording signals on a magnetic recording medium. High quality color video signal magnetic recording and reproducing device.