JPH06231402A - Video tape recorder - Google Patents

Abstract

(57) [Abstract] [Purpose] A voice recording head for deep recording is used to record and reproduce signals in a relatively wide band. [Structure] A magnetic tape M is formed by the preceding audio head Ha.
It is premised on a video tape recorder in which the audio signal Sa is deeply recorded on the inclined track on the T and the video signal Sv is recorded by the following video head HV. The width Wv of the video head is set narrower than the track pitch, and the recording track by the audio head and the recording track by the video head do not completely overlap each other, and the surface layer of the track TKa formed by the audio head Ha. Partially remain.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video tape recorder.

[0002]

2. Description of the Related Art Conventionally, in order to record and reproduce audio with high quality, a rotary magnetic head for audio signals is provided separately from the rotary magnetic head for video signals so that the audio signals are recorded deeply. Known VTRs.

In this type of VTR, as for the video signal, the luminance signal is frequency-modulated, and the carrier color signal is frequency-converted to the low frequency side of the frequency-modulated luminance signal YFM to obtain the signal CL, and both are frequency-multiplexed. Then, the frequency multiplexed signal (see the frequency spectrum in FIG. 10A) is recorded on a magnetic tape by the video signal rotary magnetic head.

On the other hand, as for the audio signal, for example, the left channel signal and the right channel signal are frequency-modulated with carrier frequencies of 1.3 MHz and 1.7 MHz, respectively,
As the frequency modulation signals LFM and RFM in the frequency band between the frequency modulation luminance signal YFM and the low frequency conversion color signal CL (see FIG. 1).
0B frequency spectrum), and deep recording is performed by a rotary magnetic head for audio signals.

That is, in actual recording, first,
Audio information Sa (= of the frequency spectrum shown in FIG. 10B
11, LFM + RFM) is deep-recorded on the tape MT as a recording layer La by the dedicated audio signal rotary magnetic head Ha configured to be capable of deep-layer recording, as shown in FIG. Then, the video information Sv (= YFM + CL) of the frequency spectrum shown in FIG. 10A is superposed on the recording layer La and is recorded on the surface layer of the tape MT by a dedicated rotary magnetic head Hv that follows the rotary magnetic head Ha. Record as Lv.

In this case, the rotary magnetic head Hv for video signals is used.
In practice, the rotary magnetic heads for audio signals Ha and the rotary magnetic heads for audio signals 180 ° with respect to each other, as shown in FIG.
Two rotary magnetic heads Hv arranged at different rotation angle positions
1, Hv2 and Ha1 and Ha2, and audio signal rotary magnetic heads Ha1 and Ha2 are attached so as to rotate prior to the video signal rotary magnetic heads Hv1 and Hv2, respectively.

As shown in FIG. 12, the magnetic gap g between the two video signal rotary magnetic heads Hv1 and Hv2.
The so-called azimuth angles of v1 and gv2 are made different from each other, and the azimuth angles of the magnetic gaps ga1 and ga2 of the two rotary magnetic heads for audio signals Ha1 and Ha2 are made different from each other. Further, the azimuths of the video signal rotary magnetic head and the audio signal rotary magnetic head arranged at the same rotation angle position are different from each other.

To simplify the description, the rotary magnetic head for video signals (hereinafter abbreviated as video head) is Hv.
And a rotary magnetic head for audio signals (hereinafter abbreviated as audio head) is represented by Ha.

The conventional rotary magnetic head for video signals Hv and the conventional rotary magnetic head for audio signals Ha are shown in FIG.
2, the width Wv of the gap gv (gv1, gv2 is represented by gv) and the gap ga (ga1,
Since the width Wa of (ga2 is represented by ga) is equal and there is no step (deviation of the mounting position in the gap width direction) at the mounting position, as shown in FIG. Pitch p equal to its width
And an inclined track TKa formed on the tape MT,
The inclined track TKv formed by the subsequent video head Hv completely overlaps, and only the recording layer Lv of the video signal Sv is formed on the surface layer of the tape MT.

Video signal Sv recorded as described above
And the audio signal Sa correspond to the corresponding heads Hv and Ha.
Is reproduced by, but as shown in FIG. 12 and FIG.
Since the two heads Hv and Ha have different azimuth angles, crosstalk between the video signal Sv and the audio signal Sa is sufficiently suppressed.

[0011]

By the way, generally, the above-mentioned audio head Ha has the performance of recording / reproducing a signal in the same frequency band as that of the video head Hv, and costs about the same. . However, conventional VT
In R, due to the restriction on the method of deep recording, as shown in FIG. 10B, as shown in FIG.
There was a problem that the original performance was not utilized, only recording and reproducing only + RFM).

In view of the above points, an object of the present invention is to provide a video tape recorder having improved performance by utilizing a magnetic head for deep layer recording.

[0013]

In order to solve the above-mentioned problems, the video tape recorder according to the present invention displays the magnetic tape MT on the magnetic tape MT by the preceding first rotary head Ha when the reference numerals of the embodiments described later are made to correspond. A video tape in which an audio signal Sa is deeply recorded on an inclined track formed at a predetermined pitch p, and a video signal Sv is recorded by being superposed on the audio signal Sa by a second rotary head Hv that follows. In the recorder, the width of the magnetic gap of the second rotary head is set narrower than the predetermined pitch, and the recording track by the first rotary head and the recording track by the second rotary head are completely Is characterized by not overlapping.

[0014]

With this structure, the inclined track TKa formed by the first rotary head Ha partially overlaps the inclined track TKv formed by the second rotary head Hv. Therefore, the surface layer of the inclined track formed by the first rotary head Ha partially remains. Therefore, it becomes possible to reproduce the signal recorded on the surface layer of a part of the deep-recorded track, and the first rotary head can record and reproduce the signal in a wider band than the conventional one.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the video tape recorder according to the present invention will be described below with reference to FIGS.

As shown in FIG. 2, in this embodiment, the gap width Wa of the audio head Ha is set equal to the track pitch p, and the gap width Wv of the video head Hv is set.
Is set narrower than the track pitch p. Then, both heads Hv and Ha are mounted so that their centers in the gap width direction rotate in unison, that is, they are mounted without a step, and the audio head Ha precedes the video head Hv by the mounting distance d. In this state, it is attached to a rotary drum (not shown).

On the tape MT, as shown in FIG. 1, the audio head Ha sequentially forms inclined tracks TKa having a track width equal to the pitch p, and the video head Hv also causes a track width Wv (<p). Tracks TKv are formed so as to overlap each other only in the center portion of the track TKa in the width direction. That is, the video head Hv
Is smaller than the track pitch, a portion of the track TKa formed by the audio head Ha that is not scanned by the video head Hv occurs, and therefore the track TK formed by the audio head Ha.
a and a track TKv formed by the video head Hv
Does not completely overlap, and a part of the surface layer of the track TKa recorded by the audio head Ha is recorded on the video head Hv.
It remains without being erased. Therefore, this track T
It is possible to reproduce the signal recorded on the surface layer of the partially remaining Ka.

The width Wa of the voice head Ha can be set larger than the track pitch p. In that case, part of the track TKa is in a so-called overwritten state, and as a result, the track has a width equal to the pitch p.

As described above, the signal can be reproduced by the audio head Ha even in a part of the surface layer of the track TKa recorded by the audio head Ha. Therefore, by using this part, a signal other than the audio signal can be reproduced. A signal can also be frequency-multiplexed with an audio signal and recorded and reproduced.

Therefore, in this embodiment, assuming a recording pattern as shown in FIG. 1, a recording system as shown in FIG. 3 and a reproducing system as shown in FIG. , And the carrier color signal C is recorded / reproduced by frequency-multiplexing with the audio signal Sa (LFM + RFM).

In FIG. 3, 10 is a video recording system,
Reference numeral 20 is a voice recording system. In the video recording system 10, the composite video signal input from the input terminal 10i is separated into the luminance signal Y and the carrier color signal C by the Y / C separation circuit 11, and the luminance signal Y includes the luminance including the frequency modulator 12fm. The carrier color signal C is sent to the signal processing circuit 12 by the color signal processing circuit 13.
, Respectively. Then, the luminance signal processing circuit 1
The output YFM of 2 is supplied to the adder 15 via the delay circuit 14, and the output of the color signal processing circuit 13 is supplied to the low frequency conversion circuit 17 via the delay circuit 16.

In the low frequency conversion circuit 17, the frequency of the color subcarrier is, for example, 3.58 MHz to 629 kHz.
The low-frequency conversion carrier color signal C is frequency-converted so that
L is formed, and this signal CL is frequency-multiplexed with the FM luminance signal YFM in the adder 15 as shown in FIG. 5A, is supplied to the video signal head Hv through the recording amplifier 18, and is recorded on the tape MT. It The delay circuit 1
The delay times τ14 and τ16 of 4 and 16 are appropriately set corresponding to the attachment distance d (see FIG. 2) between the video head Hv and the audio head Ha. In the audio recording system 20 of this embodiment, a stereo audio signal (L) composed of the audio signal L of the left channel and the audio signal R of the right channel input from the terminal 20i.
+ R) is supplied to the frequency modulation circuit 21, and an audio signal Sa (LFM + RFM) as shown in FIG. 5B is formed and supplied to the adder 22.

In this embodiment, the carrier color signal from the color signal processing circuit 13 is supplied to the synchronizing signal inserting circuit 24 and the luminance signal Y from the Y / C separating circuit 11 of the video recording system 10 is synchronized. It is supplied to the separation circuit 23 to separate the horizontal synchronization signal, and the horizontal synchronization signal is supplied to the synchronization signal insertion circuit 24. Then, in the synchronizing signal inserting circuit 24, a horizontal synchronizing signal used for correcting the time axis of the carrier color signal C recorded by the audio head at the time of reproduction is inserted into the carrier color signal C. And
The carrier color signal added with the sync signal from the sync signal insertion circuit 24 is supplied to the adder 22 and frequency-multiplexed with the audio signal Sa (LFM + RFM) as shown in FIG. 5B.
It is supplied to the video signal head Ha through the recording amplifier 25 and recorded on the tape MT.

In FIG. 4, 30 is a video reproducing system,
Reference numeral 40 denotes an audio reproducing system, to which RF signals are supplied from the video head Hv and the audio head Ha, respectively. The output of the amplifier 31 of the video reproduction system 30 is separated by the high-pass filter 32 and the low-pass filter 33 into the frequency-modulated luminance signal YFM and the low-pass conversion carrier color signal CL, and the frequency demodulator 34fm.
Are supplied to the luminance signal processing circuit 34 including the high frequency conversion circuit 35 and the high frequency conversion circuit 35. In the high frequency conversion circuit 35, contrary to the low frequency conversion circuit 17 of the recording system 10, the frequency of the color subcarrier is, for example, from 629 kHz to 3.58 MH.
The low-frequency conversion carrier color signal CL is restored to the carrier color signal C of the original carrier frequency by frequency-converting so as to become z.

The output Y of the luminance signal processing circuit 34 is the adder 3
6 and the output C of the high frequency conversion circuit 35 is
The color signal processing circuit 38 is passed through the a side end of the changeover switch 37.
And the output of the color signal processing circuit 38 is supplied to the adder 3
6 and the composite video signal from the adder 36 is supplied to the terminal 3
It is derived to 0o.

Next, in the audio reproduction system 40, the output of the amplifier 41 is the bandpass filter 42, the high-pass filter 43,
It is commonly supplied to the low-pass filter 44. An audio signal Sa is obtained from the bandpass filter 42, the audio signal Sa is supplied to the frequency demodulation circuit 45, and the stereo signal (L + R) is derived to the terminal 40o.

Further, the carrier color signal C recorded on the higher band side of the audio signal Sa is obtained from the high-pass filter 43, and this carrier color signal C is the A / D converter 51 of the time axis correction circuit 50.
Is supplied to. Then, the output of the low-pass filter 44 is supplied to the sync separation circuit 46, and the sync signal recorded together with the carrier color signal is obtained therefrom and supplied to the PLL 52 of the time axis correction circuit 50. From the PLL 52, a clock including the same time axis error as the synchronizing signal supplied thereto is obtained.

In the time axis correction circuit 50, the A / D converter 5
The data Dc of the carrier color signal C converted by 1 is P
It is written in the memory 53 by the clock from the LL 52, and is read from the memory 53 by the clock from the fixed oscillator 54 with no time axis error. The reading from the memory 53 is performed by the luminance signal processing circuit 34 of the video reproduction system 30.
Is separated from the output signal Y of
It is reset by the synchronization signal S47. The carrier color signal data Dc read from the memory 53 is transferred to the D / A converter 5
The carrier color signal C is returned by 5 and is supplied to the end of the changeover switch 37 on the b side.

When a tape recorded by frequency-multiplexing the audio signal Sa with the audio head Ha is reproduced by the recording system as shown in FIG. Thus, the changeover switch 37 is connected to the end on the b side. Further, when the conventional device reproduces the tape in which only the low-frequency conversion carrier color signal CL is recorded as the carrier color signal, the switch 37 is switched to the a side end contrary to the illustration.

When the tape recorded by the apparatus of this embodiment is reproduced by the conventional apparatus, the audio head Ha for recording / reproducing the carrier color signal C is a normal image as shown in FIG. Video head H for recording / reproducing signals
Since v and the azimuth angle are different, the carrier color signal C recorded on the track TKa is output to the reproduction output of the video head Hv.
Is not reproduced as crosstalk, and compatibility with the conventional device is ensured.

As described above, in this embodiment, recording / reproducing is performed without frequency conversion of the carrier color signal C in a system different from the normal video signal system, so that the low range of the carrier color signal is obtained. The deterioration of the reproduced image quality associated with the conversion is removed, and the quality of the reproduced image is significantly improved. In this embodiment, the carrier color signal C is recorded by frequency-multiplexing with the audio signal Sa (= LFM + RFM), but not limited to the carrier color signal C, for example, a sub screen for a so-called two-screen television sub-screen. It is also possible to multiplex record a relatively wide band signal such as a video signal and a character information signal.

In the above-described embodiment, the track TKa formed by the audio head Ha and the track TKv formed by the video head Hv are aligned so that the center lines thereof coincide with each other, that is, the two heads Hv and Ha are arranged without a step. However, when recording is performed so that the edges of the track TKa and the track TKv coincide with each other as shown in FIG. 6, the same operation as in the above-described embodiment can be obtained and the same effect can be obtained. .

In this case, the video head Hv and the audio head Ha have the same magnetic gap width as in the above-mentioned example, but as shown in FIG. In addition, it is arranged so that an appropriate step hc is generated.

8 and 9 show another embodiment of the present invention. That is, in this example, as shown in FIG. 8, the gap widths Wa and Wv of the video and audio heads Ha and Hv are set narrower than the track pitch p, and the heads Ha and Hv are set in the gap width direction. , H
It is arranged so that a step is generated by shifting only e. In the case of this example, the gap widths Wa and W of both heads Ha and Hv are
v may be equal to each other or may have different widths.

According to the rotary heads Ha and Hv having the structure of FIG. 8, as shown in FIG. 9, a guard band is formed between adjacent tracks of the track TKv formed by the head Hv, and similarly, Recording is performed in a state where a guard band is formed between adjacent tracks of the track TKa formed by the head Ha. And
The track TKa and the track TKv partially overlap,
Since the surface layer of a part of the track TKa remains, the track TKa operates in the same manner as in the above-described embodiment, and the same effect can be obtained.

[0036]

As described above, according to the present invention, the preceding rotary head capable of deep recording records an audio signal on the magnetic tape as an inclined track having a predetermined pitch, and the succeeding second head. In the video tape recorder in which the video signal is recorded by the rotary head, the inclined track recorded by the preceding rotary head and the formation track of the second rotary head are prevented from completely overlapping. The surface layer of the inclined track formed by the preceding rotary head can be partially left, and by utilizing this portion, recording and reproduction of a wide band signal can be performed by the preceding head.

[Brief description of drawings]

FIG. 1 is a plan view showing a recording pattern of an embodiment of a video tape recorder according to the present invention.

FIG. 2 is a schematic diagram showing an example of the configuration of a rotary head according to an embodiment of the present invention.

FIG. 3 is a block diagram showing an example of a recording system according to an embodiment of the present invention.

FIG. 4 is a block diagram showing an example of a reproducing system according to an embodiment of the present invention.

FIG. 5 is a frequency spectrum diagram for explaining the operation of the embodiment of the present invention.

FIG. 6 is a plan view showing a recording pattern of another embodiment of the present invention.

FIG. 7 is a diagram showing a configuration of a rotary head according to another embodiment of the present invention.

FIG. 8 is a diagram showing a configuration of a rotary head according to another embodiment of the present invention.

FIG. 9 is a plan view showing a recording pattern of still another embodiment of the present invention.

FIG. 10 is a frequency spectrum diagram for explaining the operation of the conventional video tape recorder.

FIG. 11 is a conceptual diagram for explaining the operation of the conventional example.

FIG. 12 is a diagram showing a configuration of a rotary head of a conventional example.

FIG. 13 is a plan view showing a recording pattern of a conventional example.

[Explanation of symbols]

 10 video recording system 20 audio recording system 30 video reproduction system 40 audio reproduction system 50 time axis correction circuit Ha audio head Hv video head

Claims (3)

[Claims] 1. An audio signal is deeply recorded on an inclined track formed on a magnetic tape at a predetermined pitch by a preceding first rotary head, and a video signal is converted into the audio signal by a subsequent second rotary head. In the video tape recorder, the width of the magnetic gap of the second rotary head is set narrower than the predetermined pitch, and the recording track of the first rotary head and the Two
A video tape recorder characterized in that the recording track by the rotating head of is not completely overlapped. 2. An audio signal is deeply recorded on a slanted track formed on a magnetic tape at a predetermined pitch by a preceding first rotary head, and a video signal is converted into an audio signal by a subsequent second rotary head. In the video tape recorder adapted to be superposed on the recording medium, the first and second rotary heads are arranged so as to be offset from each other in the width direction of the magnetic gap with a predetermined step, and the first rotary head is used for recording. Truck and second above
A video tape recorder characterized in that the recording track by the rotating head of is not completely overlapped. 3. The video tape recorder according to claim 1, wherein the first rotary head frequency-multiplexes and records an audio signal and a relatively wideband signal.