JPS59221802A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To record and reproduce simultaneously a video signal and a digital signal, and to use a device for a multi-purpose by providing a recording and reproducing system of a digital signal, in addition to a recording and reproducing system of a video signal. CONSTITUTION:A modulating means 3 FM-modulates a video signal extracted by a separating means 2, a memory means 6 stores temporarily an extracted digital signal of the means 2, and a modulating means 7 executes a digital modulation of an output of the means 6. Also, recording and reproducing means 5, 9 record the modulated signals of the means 3, 7 in different tracks of a magnetic tape, also reproduce them from the tape, and demodulating means 10, 12 demodulate the reproducing signals of the means 5, 9 to the video signal and the digital signal, respectively. Also, the digital signal of the means 12 is stored temporarily in a memory 13, so that a reproducing video signal and a reproducing digital signal can be obtained from the output side of the means 10 and the output side of the means 13, respectively, at the time of reproducing, and a device can be used for a multi-purpose.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an apparatus for recording and reproducing video signals and digital signals on a magnetic tape.

Conventional configuration and its problems In recent years, among devices for recording and reproducing video signals on magnetic tape, two types of video tape recorders (hereinafter abbreviated as VTR), VH3 system and β system, have been used as devices for general households. has been put into practical use. The VH8 system allows 2 hours of recording and playback at 4G standard, and the β system allows 1 hour of recording and playback at F standard.

Furthermore, recently, in addition to these standards, models that are capable of recording and playing back for longer periods of time with the same cassette have been put into practical use. For example, with a VH8 system VTR, the same cassette that can record and play back two hours can record and play back three times as long, six hours. This increases the tape feed speed to 33 on a 2 hour machine.
, 11.1M+1/S, about 1/3゛ from 4am/S
Since the feed speed is set to , the track width for recording video signals on this IC is narrower. The advancement in technology that has made long-term recording and playback possible is due to the reduction in S/N of the video signal due to the narrower video A track, as well as measures to address the problem of crosstalk from adjacent tracks, and improvements in high sensitivity. , the adoption of low-noise video heads and accompanying advances in circuit technology such as lower noise.

In addition, as a recording and playback system that enables long-time recording, for example, the VH8 system has traditionally been a two-head system,
There is a 4-head system. The 2-head system has 2 narrow track widths.
．． This is a system that uses 2 heads that are shared for 6 hours, and the 4-head system has 2 heads for 2-hour edges and 2 heads for 6-hour edges.
This system uses four different heads depending on the recording time. For example, of the recording pattern on the tape of the former two-head system, only the video signal recording portion is briefly shown in FIGS. 1 and 2.

FIG. 1 is a video signal recording pattern diagram for the 6-hour edge mode, and FIG. 2 is a video signal recording pattern diagram for the 2-hour edge mode. In Figure 1, the track pitch is 19.3
μ, track width number 19.3. However, in FIG. 2, the track pitch is 58 μm, which is the standard for VH8 VTRs, and the track width is about half, 29 μm. Therefore, in terms of tape usage efficiency, it is halved, which means that there are many cases where there is no improvement. On the other hand, teletext and PCM (P
(ulse Code Modulation) A magnetic recording and reproducing apparatus that can simultaneously record and reproduce digital signals such as audio is desired.

OBJECTS OF THE INVENTION An object of the present invention is to provide a magnetic recording and reproducing apparatus that can be used for multiple purposes by recording digital signals such as PCM recording and teletext between the video signals shown in FIG.

Structure of the Invention According to the magnetic recording and reproducing apparatus of the present invention, a separating means separates an input television signal into a video signal and a digital signal; a first modulating means performs FM modulation on the video signal extracted by the separating means; a first memory means for temporarily storing the digital signal extracted by the separation means; a second modulation means for digitally modulating the digital signal output from the first memory means; and first and second modulation means. A recording/reproducing means for alternately recording and reproducing modulated signals on different tracks on a magnetic tape and reproducing them from the magnetic tape; 2 demodulating means;
and second memory means for temporarily storing the digital signal output from the second demodulating means, the reproduced video signal is obtained from the output side of the first demodulating means during reproduction, and the reproduced video signal is reproduced from the output side of the second memory means. It is characterized by being configured to obtain a digital signal.

DESCRIPTION OF EMBODIMENTS FIG. 3 shows a block diagram of a recording/reproducing circuit of a magnetic recording/reproducing apparatus according to an embodiment of the present invention. 1 is T
V signal input terminal, 2 is a character signal extraction circuit that separates and extracts a video signal and character signal, 3 is a video signal recording circuit that modulates the video signal with FM, 4 is a first recording/playback changeover switch, 5 is a video signal recording/playback Head H1 and H2
Consisting of

6 is a first buffer 7 memory, 7 is a digital signal recording circuit that digitally modulates the g signal, 8 is a second recording/playback changeover switch, and 9 is a digital signal recording/playback head consisting of a head H3 and a head 14. .

10 is a video signal reproducing circuit, 11 is a video signal output terminal, 12 is a digital signal reproducing circuit, 13 is a second buffer memory, 14 is a video signal converting circuit, and 15 is a text information video signal output terminal.

The TV signal input from the TV signal input terminal 1 is input to the character signal extraction circuit 2, which separates it into a video signal and a character signal, converts the video signal into a video signal, and converts the character signal into a character signal. Convert to digital signal and output. The video signal output from the character signal extraction circuit 2 is input to the video signal recording circuit 3. For example, if it is an NTSC video signal, it is separated into a luminance signal and a color signal, and the luminance signal is converted into a low carrier FM signal. , the color signal is also converted into a low frequency converted color signal, and a signal obtained by superimposing both is output to the first recording/reproduction changeover switch. During recording, the first recording/reproducing changeover switch is connected to the video signal recording circuit 3. Video signal recording/playback head 1-11, H2
is driven by the output signal of the video signal recording circuit 3, and the video signal is recorded on the tape.

Further, the character signal outputted from the character signal extraction circuit 2 is inputted to the first buffer 7 memory 6. When the character signals for one screen are input to the first buffer 7 memory 6, the character signals for one screen are output to the digital signal recording circuit 7. In the digital signal recording circuit 7, the character signal consisting of a header part and a data part is divided into every n blocks as shown in FIG. 4, and a synchronization signal and a correction code are added to each block to form a frame. After applying, for example, MFM modulation, the signal is output to the second recording/reproduction changeover switch 8.

The digital signal recording and reproducing heads H3 and H4 record the character signal output from the digital signal recording circuit 7 onto the tape.

FIG. 5 shows heads H1 and H of the video signal recording/reproducing head 5.
2. Heads H3 and H4 of the digital signal recording/reproducing head 9
FIG. 6 shows a recording pattern on the tape. In FIG. 5, two heads H1 and H2 for recording and reproducing video signals are located on a diagonal line of 1800 mm from each other, and similarly recording and reproducing digital signals.
The heads H3 and H4 are also located on the diagonal line of 1800,
The mounting heights of 1-11, H2, 1''3, and H4 are adjusted so that they trace different tracks, respectively.

Therefore, as shown in FIG. 6, for example, when head 1"1 records a video signal on track #1, head H
3, digital signals can be recorded on racks #1'1 to #1'1. Here, the tracks #1 and #1' are close to each other, but if the prior art inclined azimuth recording method is used, the influence of adjacent tracks when track deviation occurs can be reduced even without a guard band. The relationship between heads H2 and H4 is the same as that between heads H1 and H3, and the recording pattern shown in FIG. 6 is formed.

During reproduction, the first recording/reproduction changeover switch 4 and the second recording/reproduction changeover switch 8 are connected to the video signal gH main circuit 10 and the digital signal reproduction circuit 12, respectively. Video signal recording/playback head 5 head +1
, H2 is input to the video A signal reproducing circuit 10 through the first recording/reproducing changeover switch 4. The video signal reproducing circuit 10 performs FM demodulation on the reproduced signal, converts the luminance signal and color No. 16 to 0, and outputs the resulting signal from the video signal output terminal 11. On the other hand, the character signal reproduced by the heads 1-13.1-14 of the digital signal recording/reproducing head 9 is inputted to the digital signal reproducing circuit 12 through the second recording/reproducing changeover switch 8. After performing MFM demodulation in the digital signal reproducing circuit 12,
After detecting the signal I'] and performing error correction using a correction code for each frame, character signals are separated and output to the buffer memory 13. When the buffer memory 13 receives character signals for one screen, it is output to the video signal converting circuit 14. The video signal circuit 14 decodes the character signal, which is a digital signal, and outputs it as a video signal from the character information video J& signal output terminal 15.

By switching the output to the television receiver between the video signal and the text information video signal, it becomes possible to select and view both.

As described in the detailed description of the invention, according to the magnetic recording device of the present invention, a recording and reproducing system for digital signals in previsicon signals is provided separately from a recording and reproducing system for video signals. Its practical effects are great in that it can record and reproduce signals simultaneously and can be used for more purposes than conventional ones.

[Brief explanation of the drawing]

Figures 1 and 2 are recording pattern diagrams in the 6-hour mode and 2-hour edge mode of the VH8 system as a conventional magnetic recording device, and Figure 3 shows an example of the present invention. (Figure 4 is a block diagram of a magnetic recording and reproducing device. Figure 4 is a frame configuration diagram of character information. Figure 5 is an explanatory diagram of the position of the head in Figure 3. Figure 6 is a recording pattern diagram in Figure 3.) 1... TV signal input terminal, 2... Character signal extraction circuit [separation means], 3... Video signal recording circuit (first modulation means), 5... Video signal recording/reproducing head, 6・・・
- first buffer memory, 7... digital signal recording circuit, 9... digital signal recording/reproducing head, 10...
Video signal regeneration circuit [first demodulation means], 11... video signal output 9; Buffer memory of 2, 15...Text information video signal output terminal cost 1.14 people Hiroshi Morimoto Figure 1

Claims (1)

[Claims] 1. Separation means for dividing an input television signal into a video signal and a digital signal; a first modulation means for FM modulating the video signal extracted by the separation means; and a first modulation means for FM modulating the video signal extracted by the separation means; A first memory means for temporarily storing a digital signal, a second modulation means for digitally modulating a digital signal output from the first memory means, and a magnetic tape that alternately modulates the signals modulated by the first and second modulation means. a recording/reproducing means for recording on different tracks on the magnetic tape and reproducing from this magnetic tape; and a first recording/reproducing means for demodulating the signals reproduced by the recording/reproducing means into video signals and digital signals, respectively.
, comprising a second demodulating means and a second memory means for temporarily storing the digital signal output from the second demodulating means, and obtaining a reproduced video signal from the output side of the first Wi modulating means during reproduction;
A magnetic recording/reproducing device developed to obtain a reproduced digital signal from the output side of a second memory means.