JPS5962287A - Video tape recorder - Google Patents

Abstract

PURPOSE:To attain the after recording, by recording a luminance signal and a chroma signal on a different track so as to obtain a reproduced picture with high quality and recording independently a sound signal on different tracks. CONSTITUTION:A rotary magnetic head recording and reproducing an FM luminance signal is provided on a cylinder (not shown in the figure), luminance and chrominance signal video tracks 14a, 15a are formed on a magnetic tape 1 at the same time, and similarly luminance signal video tracks 14b, a chroma signal track 15b are formed respectively at the same time, the 1st sound signal overlap tracks 16a, 16b- are formed on the prolonged line of luminance signal video tracks 14a, 14b- and overlap tracks 17a, 17b- for the 2nd sound signal recorded independently of the 1st sound signal are formed on the prolonged line of the chroma signal video tracks 15a, 15b-.

Description

Detailed Description of the Invention [Field of Application of the Invention] The present invention relates to a video tape suitable for recording luminance signals, color signals, and two-channel audio signals on recording tracks formed diagonally on a magnetic tape. Regarding recorders.

[Prior art]

With the spread of video tape recorders, interest in video tape recorders is increasing, and in recent years, a small video tape recorder integrated with a video camera has been proposed, improving its mobility and unifying some standards. For this reason, it is attracting a lot of attention.

By the way, as a result of the research and development of video tape recorders to date, the image quality of reproduced images has significantly improved, but there has been no definitive means for improving the quality of audio. However, in recent years, technological developments have progressed in converting audio signals to PCM (Pulse Code Modulation), which has significantly improved audio quality. Even in the video camera-integrated video tape recorder described above, which does not require converting the signal into PCM, a recording and reproducing method by converting the audio signal into PCM is adopted so that high-quality audio can be reproduced.

FIG. 1 is an explanatory diagram showing an example of such a conventional video tape recorder, in which 1 is a magnetic tape, 2 is a preliminary audio signal recording track, 3 is a preliminary track on which the user can record cue signals, etc.; is an overlap track, and 5 is a video track. Note that arrow 6 indicates the moving direction of the magnetic tape 1, and arrow 7 indicates the moving direction of the rotating magnetic head (not shown) on the magnetic tape 1. In the figure, the magnetic tape 1 is connected to two rotating magnetic heads. are wound around cylinders (not shown) provided at 180° intervals over a length of about 210°, and the rotating magnetic head
This approximately 210° cylinder winding is done by magnetic tape 1 only at the corners.
By scanning, a recording track consisting of an overlap track 4 and a video track 5 is sequentially formed in the direction opposite to the arrow 6, and the recording track is reproduced and scanned.

The overlap track 4 has a cylinder wrap corresponding to about 30 degrees of the corner, and the video track 5 has a cylinder wrap corresponding to about 180 degrees of the corner. When the video track 5 is moving and scanning on the overlap track 4, the other rotary magnetic head is moving and scanning the end portion of the cylinder winding of the video track 5, which corresponds to about 30° of the corner, and the two This means that the scanning periods of the magnetic tape 1 by the rotating magnetic heads partially overlap.
Two channels of audio signals and a pilot signal f are recorded. Audio signal A1. A2 is converted into PCM (pulse code modulation), mixed on the time axis, and time-compressed. On the video track 5, a luminance signal Y11 signal C and a pilot signal f are recorded. Then, for each video track 5, a luminance signal Y and a chrominance signal C are recorded for one field period, and in a certain video track 5, the luminance signal YA and the chrominance signal C of an odd field are recorded.
In the adjacent video track 5, even field luminance signal YB and chrominance signal cB are recorded, and even field luminance signal YB and chrominance signal cA are recorded, as well as odd field luminance signal YB and chrominance signal cA. YB and color signals cB are recorded on alternate video tracks 5.

The pilot signal f has a carrier frequency fl + f2
+f3. The four pilot signals f, (hereinafter referred to as pilot signals flT') 21f31f4), different pilot signals are recorded for each recording track, so that the pilot signals recorded between adjacent tracks are different. Additionally, the pilot signals recorded on the video track 5 and the overlap track 4 are made different. In other words, when the recording tracks formed on the magnetic tape 1 are viewed sequentially in the direction indicated by the arrow 6, a pilot signal f□ appears in the video track 5 of a certain recording track, and a pilot signal f4 appears in the overlap track 4. is recorded, a pilot signal f2 is recorded on video track 5 of the next recording track, a pilot signal f1 is recorded on overlap track 4, and a pilot signal is also recorded on video track 5 of the next recording track. f3, pilot signal f2 is recorded on overlap track 4, pilot signal f4 is recorded on video track 5 of the next recording track, pilot signal f3 is recorded on overlap track 4, and the following four recording tracks are recorded. The recording order of the pilot signals is repeated with . In this way, by recording the pilot signal on each recording track, tracking adjustment during reproduction of the rotary magnetic head is performed. The frequency of the pilot signal is
- As an example, f, medium 6.51H, f2'=F7.5fH
.

It is set to 10.5 fH in f3 and 9.5fa in f4 (however, fH is the horizontal synchronizing signal frequency).

Each signal recorded on the video track 5 is frequency division multiplexed, and an example of their frequency spectrum is shown in FIG. The luminance signal is frequency modulated and recorded (
(Hereinafter, such a brightness signal is referred to as an FM brightness signal), its frequency spectrum C is composed of an FM carrier 8 with a predetermined frequency shift, a lower sideband wave 11, and an upper sideband wave 12, and the total frequency band occupied by these is FMM. This is the frequency band of the signal.

The color signal 9 is obtained by frequency converting the carrier color signal to a lower frequency band, and its frequency band is set below the FM luminance signal. Furthermore, the frequency band of the pilot signal 10 is set below the color signal 90 frequency band.

As mentioned above, in the conventional video cheap recording,
A color video signal and an audio signal are recorded, but as is clear from Fig. 2, since the FMQ intensity signal and the color signal are frequency division multiplexed, the frequency band of the FM luminance signal is is limited by the frequency band of the chrominance signal, and as a result, the frequency band of the FM luminance signal cannot be widened sufficiently, and the resolution of the luminance signal is inevitably lowered. However, since subcarriers are present in the color signal, color unevenness occurs due to jitter that is characteristic of video tape recorders.

Additionally, in general, video tape recorders need to be able to perform after-recording, in which the already recorded audio signals are erased and new audio signals are recorded. In a recorder, the two channels of audio signals recorded on the overlap track are mixed on the time axis and time-compressed, so only one of these audio signals can be erased to create a new audio signal. It is extremely difficult to perform after-recording in which signals are recorded.

One possible solution to this problem is to record each audio signal at separate locations on the overlap track. According to this, after-recording of either audio signal can be easily performed, but in this case, the cylinder wrap of about 30 degrees divides the overlap track corresponding to the corner into two areas. death,
It is not possible to record one audio signal in one area and the other audio signal in the other area, however, because the interleaving length of each is short, the error correction ability is significantly degraded and is not practical. It won't be.

Therefore, in order not to shorten each interleave length,
Wrap the magnetic tape around the cylinder by approximately 30° further around the corner.
There is a method of increasing the overlap track, pointing the cylinder winding rate at about 60' of the corner, dividing the overlap track into two areas, and recording two channels of audio signals as described above. It is possible, but with this method,
Although there is no deterioration in the error correction ability, the angle when the magnetic tape is wrapped around the cylinder increases from about 210° to about 250°, making it difficult to load and run the magnetic tape stably.

[Purpose of the invention]

An object of the present invention is to provide a video tape recorder which can obtain high-quality reproduced images and easily perform after-recording on either one of two channels of audio signals, while eliminating the drawbacks of the prior art. :Ij
It is in the % offer.

[Ready-made invention]

To achieve this object, the present invention extends the frequency band of the luminance signal by recording the luminance signal and the chrominance signal on different video tracks, and improves the frequency band of the luminance signal by recording the luminance signal and the color signal on different video tracks. The present invention is characterized in that different audio signals are recorded on each track, and each audio signal can be recorded and erased independently.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 is an explanatory diagram showing an embodiment of the video tape recorder according to the present invention, in which reference numeral 13 indicates a control track;
14a, i4b, 14c, -1' are video tracks for luminance signals, 15a, 15b, 15c, . . . are video tracks for color signals, and 16a.

16b, 16c, . . . are overlap tracks for the first audio signal, 17a, 17b, 17c, .
. . . is an overlap track for the second audio signal, and parts corresponding to those in FIG. 1 are given the same reference numerals.

In FIG. 3, the winding angle of the magnetic tape 1 around a cylinder is similar to that of the conventional video tape recorder 7 shown in FIG. A rotating magnetic head (not shown) and a rotating magnetic head (not shown) for recording and reproducing color signals are provided, and these rotating magnetic heads create a luminance signal video track 14a on the magnetic tape 1. and the color signal video track 15a are formed at the same time, and similarly, the luminance signal video track 141) and the color signal video track 1 are formed at the same time.
5b, a video track 14c for a luminance signal and a video trunk 15c for a chrominance signal are simultaneously formed, respectively, and along with this, a video track i4a for a luminance signal,
14b, 14c, ...... each extension line,
First audio signal overlap tracks 16a, 16b
+16c+""" is also the second audio signal overlap track 17a, on the extension line of the color signal video track 15a, 15bl 15(!1...).
17b, 17c, . . . are formed.

Odd field FM luminance signals and color signals are recorded in the luminance signal video track 14a and the chrominance signal video track 15a, respectively.
Even-field FM luminance signals and chrominance signals are recorded in the b5 color signal video track 15b, and odd-field FM luminance signals and chrominance signals are recorded in the luminance signal video track 14c and the chrominance signal video trunk 15c, respectively. is,
Thereafter, in the same manner, the FM luminance signal and the color signal are recorded alternately in odd and even fields on different video tracks.

Overlap track 16a for first audio signal.

16b, 16c, . . . record the first audio signal, and overlap track 17a for the second audio signal.
, 17b+17c, . . ., the second audio signal is recorded. 1st. The second audio signal is a time-compressed PCM audio signal, and the magnetic tape 1 is wound around the cylinder to two rotating magnetic heads (not shown) scanning an overlapping portion of about 30 degrees. ．． By simultaneously supplying the second audio signal, the respective audio signals are recorded as described above.

However, the first audio signal overlap track 16
a, 16b, 16c, . . . and second audio signal overlap tracks 17a, 17b.

17c, . . . can be erased and recorded independently of each other, and after-recording can be performed independently for each.

Note that a control pulse is recorded in the control track 13, and tracking during reproduction is performed using the control pulse.

FIG. 4 shows the luminance signal video tracks 14a and 1 of FIG.
4b, 14c, -- is a spectrum diagram showing a specific example of the FM luminance signal recorded on the FM luminance signals, and the same reference numerals are given corresponding to the spectrum of the FM luminance signal in FIG. 2.

As is clear from FIG. 4, since color signals are not recorded on the video tracks 14a+ 14b, 1401-, etc. for luminance signals (FIG. 3), the FM
The frequency band of the luminance signal can be expanded, and the resolution of the reproduced image can be greatly improved.

FIG. 5 shows the color signal video track 15a + of FIG.
15 b + 15 c + . . . is a spectral diagram showing a specific example of a color signal recorded.

In FIG. 5, the color signal is a signal obtained by frequency division multiplexing a first color difference signal and a second color difference signal,
．． The second color difference signal may be the R-Y signal and the B-Y signal, or the ■ signal and the Q signal,
Each is frequency modulated. The first color difference signal consists of an FM carrier 18 with a predetermined frequency shift, a lower sideband wave 19, and an upper sideband wave 20, and the total frequency band of these old bands is:
This is the frequency band of the first color difference signal. -1: f? ,,,
The second color difference signal is an FM carrier 2 with a predetermined frequency shift.
1, a lower sideband wave 22, and an upper sideband wave 23. These first
．． Since there is no subcarrier in the second color difference signal,
It is not affected by jitter, and color unevenness does not occur in the reproduced image. t7t, 1st. It is possible to set a large frequency shift for the second color difference signal, and the S/N of the color signal is improved.

Note that the color signal video track 15a in FIG.

The color signals recorded in 15b, 15c, . . . are not limited to those shown in FIG.
For example, 1st. The second color difference signal may be time-compressed to about 1/2, time-division multiplexed, and may be a frequency-modulated signal.

FIG. 6 is an explanatory diagram showing another embodiment of the video tape recorder according to the present invention, and parts corresponding to those in FIG. 3 are given the same reference numerals.

This embodiment is similar to the embodiment shown in FIG. 3, except that a pilot signal is recorded on each recording track and tracking adjustment during reproduction is performed using the pilot signal.

In FIG. 6, a video track for a luminance signal and a video track for a chrominance signal (for example, a video track 14a for a luminance signal and a video track 15 for a chrominance signal) are formed simultaneously.
a) (hereinafter referred to as a video track pair), the same pilot signal is recorded, and in sequential video track pairs, different pilot signals are recorded sequentially, as in the case of video track 5 in FIG. .

1st. The same applies to the second audio signal overlap track, which is formed simultaneously to form an overlap track for the first audio signal and an overlap track for the second audio signal (hereinafter referred to as an overlap track pair). The same pilot signal is recorded on each pair of overlap tracks, and different pilot signals are recorded on successive pairs of overlap tracks, as in the case of overlap track 4 in FIG.

Moreover, an overlap formed on an extension line of a certain video trunk pair (for example, a pair of a luminance signal video track 14a and a color signal video track 15a) and a video track pair formed next to the video track pair. Overlap track pair (overlap track 16b for first audio signal)
and the second audio signal overlap track 17b), the same pilot signal (for example, pilot signal h) is recorded. As a result, the recording tracks formed by the rotating magnetic head (not shown) moving in the direction of arrow 7 are formed in the order of the overlap track pair and the video track pair.
One pair of rotating magnetic heads (a rotating magnetic head that scans a video track for luminance signals and a rotating magnetic head that simultaneously scans a video track for chrominance signals, hereinafter referred to as a pair of rotating magnetic heads) For example, the cylinder winding near the ends of the luminance signal video track 14a and the color signal video track 15a has an angle of approximately 30°.
, the other rotating magnetic head pair moves between the first audio signal overlap track 16b and the second audio signal overlap track 17b of the next recording track. In fact, during this period, all four rotating magnetic heads are in contact with the magnetic tape 1, and the same pilot signal can be supplied to them. Then, at the point when one pair of rotating magnetic heads is displaced from the pair of overlap tracks to the pair of video tracks (at this point, the other pair of rotating magnetic heads is away from the magnetic tape 1), the other pair of rotating magnetic heads is transferred to the other pilot signal. A switch will take place. Therefore, the same pilot signal can be supplied to all rotating magnetic heads at the same time, and the pilot signal switching timing is also common to all rotating magnetic heads. is simplified.

7 and 8 show the luminance signal video tracks 14a, 14b+14c, 14d+14e, . . . in FIG. 6, respectively.
. . A spectral diagram showing a specific example of a signal recorded on the color signal video track 15a.

15b, 15c, 15d, . . . are spectrum diagrams showing specific examples of signals recorded in the signals, except that the Pyrosotoi δ 100 frequency band is set on the lower side of each.
This embodiment is similar to the embodiment shown in FIG. 3, and its explanation will be omitted.

FIG. 9 is an explanatory diagram showing still another embodiment of the video tape recorder according to the present invention, in which 14 is a video track for luminance signals, 15 is a video trunk for color signals, and 16t is an overlap track for first audio signals. Track 17 is a second audio signal phase overrun trunk, and parts corresponding to those in FIG. 3 are given the same reference numerals, and some explanations will be omitted.

In this embodiment, an overlapping track pair is formed after the video track sequence. That is, a pair of video tracks is formed from the point at which a pair of rotating magnetic heads (not shown) comes into contact with the magnetic tape 1, and once a pair of video trunks is formed in a portion corresponding to an angle of approximately 180 degrees, the cylinder winding is performed as follows. An overlap track pair is formed in a portion corresponding to about 30" of A track pair is formed, and all four rotating magnetic heads are in contact with the magnetic tape 1 during this period.

FIG. 10 is an explanatory diagram showing still another embodiment of the video tape recorder according to the present invention, and parts corresponding to those in FIG. 9 are given the same reference numerals, and some explanations are omitted.

In this embodiment, instead of the control pulses on the control track 13 in the embodiment shown in FIG. 9, a pilot signal is recorded on the recording track to enable tracking adjustment during reproduction. As in the embodiment shown in FIG. 6, different pilot signals are sequentially recorded for each pair of video tracks and for each pair of overlap tracks. The point at which all the rotating magnetic heads (not shown) are in contact with the magnetic tape L is when the video track pair shifts to the overlap track pair (at this point, the other rotating magnetic/magnetic head pairs are The pilot signal is switched at a point separated from the tape 1, thereby simplifying the means for supplying the pilot signal to the rotating magnetic bed.

As a result, as shown in FIG. 10, the pilot signals recorded on a certain overlap track pair and the next formed video track pair are the same. In this embodiment as well, all luminance signals and color signals are recorded using the same frequency spectrum as in the embodiment shown in FIGS. 3 and 6.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to expand the recording frequency band of the luminance signal, thereby greatly improving the resolution of the reproduced image and suppressing color shift.
High-quality reproduced images can be obtained, and furthermore, individual after-recording of two-channel audio signals can be easily performed, and a video tape recorder with excellent functions can be provided without the drawbacks of the above-mentioned prior art.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an example of a conventional video tape recorder, FIG. 2 is a spectrum diagram showing an example of a signal recorded on the video track of FIG. 1, and FIG. 3 is a diagram of a video tape recorder f invented by Lee. An explanatory diagram showing one embodiment, FIG. 4 is a spectrum diagram showing a specific example of the signal recorded on the luminance signal video track of FIG. 3, and FIG. 5 is a chrominance signal video track of FIG. 3. FIG. 6 is an explanatory diagram showing another embodiment of the video tape recorder according to the present invention, and FIG. 7 is a spectrum diagram showing a specific example of a signal recorded in the video tape recorder of FIG. FIG. 8 is a spectrum diagram showing a specific example of the signal recorded on the color signal video track of FIG. 6;
FIGS. 9 and 10 are explanatory diagrams showing still other embodiments of the video tape recorder according to the present invention. 1...magnetic tape, 14.14a, ],
, 4b, 14c, 14d, 14e... Video track for luminance signal, 15+ 15a+ 15
b, 15c, 1sa----color signal video track, 16, 16a+ 16b, 16c...
... Overlap track for first audio signal, 17.
17a, 17b, 17cm - 2nd audio signal overlap track 0 72 concave T3 figure '11'4 figure θ lρ 70 Mfh) -111 Chuo 6 Japan 712″l? 8121 PI syndrome 5 (MHz)□

Claims (1)

[Scope of Claims] (1) A video tape recorder configured to record a luminance signal, a color signal, and a two-channel audio signal on recording tracks formed diagonally on a magnetic tape, in which the luminance signal is a first recording track on which the color signal is recorded; a second recording track on which the color signal is recorded; and a first recording track on which the color signal is recorded.
A third recording track is formed on an extension of the recording trunk and records the audio signal of the one channel, and a third recording track is formed on the extension of the second recording trunk and records the audio signal of the other channel. a fourth recording track, and the first and second recording trunks are arranged alternately on the magnetic tape. (2) A video tape recorder according to claim (1), characterized in that the audio signals of the two channels are respectively time-compressed PCM audio signals. (3) Claim (1) The video tape recorder according to claim 1) or claim 2, wherein the color signal is two frequency-division multiplexed color difference signals. In section (2), the color signal is time-compressed and time-division multiplexed.
c. A video tape recorder characterized in that it uses two color difference signals.