JPH03292075A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To attain normal recording of a video signal by providing a 1st modulator receiving an output signal from a digital signal processing unit as a modulation input and supplying a modulation signal to a 1st recording and reproducing means and a 2nd modulator converting an inputted video signal into a luminance signal subject to frequency modulation and a color signal subject to low frequency conversion and supplying the converted signal to a 2nd recording and reproducing means. CONSTITUTION:A 1st signal processing unit 9 adds an error correction code to an inputted digital audio data and applies signal processing such as formatting and supplies the result to a 1st modulator 10. The 1st modulator 10 converts an input signal into a 4-phase modulation signal taking a frequency band shown in figure H into a 2.5MHz carrier frequency and gives the result to a 1st amplifier 11. A video signal fed to a 2nd input terminal 16 is inputted to a 2nd modulator 17, in which the signal is separated into a luminance signal and a chrominance signal and they are subject to frequency modulation and low frequency conversion respectively in a frequency band shown in figure I. The luminance signal subject to frequency modulation and the chrominance signal subject to low frequency conversion are added and the result is fed to a 2nd amplifier 18.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic recording/reproducing device having a digital signal input terminal conforming to the digital audio interface standard.

2. Description of the Related Art In recent years, digital audio tape recorders (hereinafter referred to as D
It is called AT. Development of systems that can record pulse code modulated signals such as those typified by ) is progressing.

This DAT, together with an analog audio signal input terminal, is connected to the Electronic Industries Association of Japan (hereinafter referred to as EIAJ).

) digital audio interface standard CP-
It has an input terminal for digital audio signals in accordance with H.340.

An example of a conventional magnetic recording/reproducing device will be described below with reference to the drawings.

FIG. 4 is a block diagram of a signal recording/reproducing section of a conventional DAT. In Fig. 4, 51 is an input terminal into which a digital signal conforming to the EIAJ digital audio interface standard is input, and 52 is an input terminal for converting the digital signal input to the input terminal 51 into a digital audio signal and adding a copy prohibition flag, a sampling frequency flag, etc. A receiver for separating information signals, 53, is a copy prohibition detector that receives the additional information signal output from the receiver 52 and detects whether a copy prohibition flag in the input signal prohibits digital copying. . Reference numeral 54 denotes a sampling frequency discriminator which receives the additional information signal output from the receiver 52 and discriminates from the sampling frequency flag in the input signal whether the digital signal has a recordable frequency or not. Reference numeral 55 denotes an OR circuit (hereinafter referred to as an OR circuit) that calculates the logical sum of the output signals of the copy prohibition detector 53 and the sampling frequency discriminator 54. A first signal processor 56 receives the digital audio signal output from the receiver 52 and processes the input signal in various ways. 57 amplifies the output signal of the first signal processor 56, and a switch 58 and a rotary transformer 5
Magnetic head group 6 attached to cylinder 60 via 9
1a and 81b. 6
2 is a magnetic tape; 83 a and 83 b are guide posts; 84 is a controller that controls the rotation of the cylinder 60 and the running of the magnetic tape 62; 65 is a magnetic head group 61 a;
31b and amplifies the signal supplied via the rotary transformer 59 and the switch 58. A second signal processor 66 processes the output signal of the second amplifier 85 in various ways and returns it to the original digital audio signal. The output signal of the second signal processor 66 is converted to a digital/analog converter (hereinafter abbreviated as a D/A converter).
At 67, the signal is converted into an analog audio signal and output to an output terminal 68.

The operation of the conventional DAT signal recording/reproducing section configured as described above will be described below.

First, the operation during recording will be explained.

A digital signal conforming to the EIAJ digital audio interface standard is input to the input terminal 51.

The digital signal input to the input terminal 51 is sent to the receiver 52.
The signal is separated into a digital audio signal and additional information signals such as a copy prohibition flag and a sampling frequency flag. The additional information signal is supplied to the copy inhibition detector 53 and the sampling frequency discriminator 64, and the digital audio signal is supplied to the first signal processor 54. The copy prohibition detector 53 detects whether the copy prohibition flag in the input additional information signal prohibits digital copying. and,
If digital copying is prohibited, a high level signal is output to the OR circuit 55. Similarly, the sampling frequency discriminator 54 discriminates from the sampling flag in the input additional information signal whether or not the digital audio signal has a recordable frequency. And if it is not possible to record (e.g.
If the digital audio signal of the input signal has a sampling frequency of 44.1kHz, and the first signal processing 56 supports only a digital audio signal with a sampling frequency of 48kHz, a high level signal is output to the OR circuit 55. do. Therefore, the OR circuit 66 outputs a high level signal to the controller 84 when digital copying is prohibited or when a digital signal with an unrecordable sampling frequency is input, and otherwise outputs a low level signal. Output. The first signal processor 5B performs signal processing such as adding an error correction code to the input digital audio signal, formatting, and 8-10 conversion.
Supply to 7. The signal amplified by the first amplifier 57 is
It is applied to a group of magnetic heads 81a and 61b with an azimuth angle of ±20° attached to a cylinder 60 via a switch 58 switched to the R side and a rotary transformer 59.

If the OR circuit 5 is outputting a high level signal, the controller 64 stops the running of the magnetic tape 62 and the rotation of the rotary cylinder 60. Therefore, the output signal of the first amplifier 57 is not recorded on the magnetic tape 62. When the OR circuit 55 is outputting a low level signal, the controller 64 causes the magnetic tape 62 to travel in the direction of arrow B as shown in FIG. 4, and further rotates the rotary cylinder 60 in the direction of the arrow. As a result, the output signal of the first amplifier 57 is recorded on the magnetic tape 62.

Next, the operation during playback will be described.

The signals reproduced by the magnetic head group 81a and Blb are transferred to the rotary transformer 50 and the switch 68 switched to the P side.
to the second amplifier 65 via. The signal amplified by the second amplifier 6L'' is multiplied by the second signal processor 66 into a digital audio signal and output to the D/A converter 67. The digital audio signal is converted into an analog audio signal and outputted to the output terminal 68.

Problems to be Solved by the Invention However, with the above configuration, when digital copying of an input digital signal is prohibited in accordance with a predetermined digital audio interface standard, or when a signal with a sampling frequency not supported by the recording device is input. If this happens, the rotation of the cylinder and the running of the magnetic tape will be stopped. Therefore, JP-A-63-17140
If the above-mentioned recording prohibition method is used with a device capable of recording a digitalized audio signal at the same time as a video signal, such as the digital audio recording video tape recorder of Publication No. 3, recording of the video signal will also be prohibited. had.

The present invention solves the above-mentioned conventional problems, and even when digital copying of an input digital signal is prohibited according to a predetermined digital audio interface standard, or when a signal with a different sampling frequency is input, An object of the present invention is to provide a magnetic recording/reproducing device that does not interfere with the recording of video signals.

Means for Solving the Problems To achieve this object, the magnetic recording and reproducing apparatus of the present invention includes two groups of recording and reproducing means for recording and reproducing signals on a magnetic tape, and for converting input digital signals into digital audio signals and copying. A receiver that extracts a prohibition flag and a sampling frequency flag, and a digital audio data converter that converts digital audio data output from the receiver into analog audio data.
an analog converter, an analog/digital converter that converts the output signal of the digital/analog converter into a digital audio signal, a detector that detects a copy prohibition flag output from the receiver, and a sample output from the receiver. A discriminator that discriminates the frequency flag; an OR circuit that computes the logical sum of the output signals of the detector and the discriminator; A switch that outputs either one of the digital audio signals to be output, a digital signal processor that adds an error correction code to the digital audio signal output from the switch, and a modulation input for the output signal from the digital signal processor. a first modulator that supplies a modulated signal to the first recording/reproducing means; and a second modulator that converts the input video signal into a frequency-modulated luminance signal and a low-frequency converted color signal It has a configuration including a second modulator that supplies data to the recording and reproducing means.

According to the above-described configuration, the present invention converts a digital audio signal into an analog audio signal when digital copying of a digital signal input through a digital audio interface is prohibited or when a digital signal with a sampling frequency not compatible with recording is input. A converter converts it back into a digital signal at a recordable sampling frequency and records it on magnetic tape. The input video signal is also converted into a frequency-modulated luminance signal and a low frequency-converted color signal, which are then recorded on a magnetic tape.

As a result of the above, even if digital copying of the input digital signal is prohibited, or even if a digital signal with an incompatible sampling frequency is input, recording of the video signal will not be hindered.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of a magnetic recording/reproducing apparatus according to an embodiment of the present invention. FIG. 2 is a characteristic diagram illustrating the frequency band of a signal to be recorded, and FIG. 3 is a diagram showing a track pattern of a magnetic tape recorded by the magnetic recording/reproducing apparatus of this embodiment.

In Figure 1, 1 is an input terminal into which a digital signal conforming to the EIAJ digital audio interface standard is input, and 2 is an input terminal for converting the digital signal input to input terminal 1 into a digital audio signal, a copy prohibition flag, a sampling frequency flag, etc. a receiver that separates the additional information signal;
3 inputs the additional information signal output from the receiver 2,
The copy prohibition flag in the signal indicates that digital copy is prohibited.
1 is a copy prohibition detector that detects whether or not the signal is stopped. 4 inputs the additional information signal output from the receiver 2, and detects from the sampling frequency flag in the signal whether the frequency is recordable for the digital audio signal or not. This is a sampling frequency discriminator that discriminates whether the 5 is an OR circuit that calculates the logical sum of input signals, and e is a D/A converter that receives the digital audio signal output from the receiver 2 and converts this signal into an analog audio signal. Reference numeral 7 denotes an analog/digital converter (hereinafter abbreviated as A/D converter) which digitizes the analog audio signal output from the D/A converter 8 at a re-recordable sampling frequency.

). 8 is a first switch that is controlled by the output signal of the OR circuit 5 and supplies an output signal from either the receiver 2 or the A/D converter 7; 9 is a first switch that supplies the digital audio signal supplied from the switch 8; This is a first signal processor that receives the digital audio signal as an input and performs various signal processing on this digital audio signal. 10 is the first
11 is a first amplifier that amplifies the output signal of the first modulator 10, and the output signal is converted into a quadrature phase modulation signal. cylinder 1 via switch 12 and first rotary transformer 13
The magnetic head is supplied to a first group of magnetic heads 15a and 15b having an azimuth angle of, for example, ±30'. 1
6 is the second input terminal into which the video signal is input; 17 is the second input terminal;
This is a second modulator that converts the video signal input to the input terminal 1B into a frequency-modulated luminance signal and a low-frequency-converted chrominance signal. 18 amplifies the output signal of the second modulator 17, and a third switch 19 and a second rotary transformer 2
A second magnetic head group 21a, 21 having an azimuth angle of ±6°, for example, is attached to the cylinder 14 through a
b. 22 is a magnetic tape; 23a and 23b are guide posts; 24 is a control device that controls the rotation of the cylinder 140 and the running of the magnetic tape 22; and a third amplifier that amplifies the signal supplied via the second switch 12, and 26 is a first demodulator that demodulates the output signal of the third amplifier 25 into a digital signal.

27 performs various signal processing on the output signal of the first demodulator 26;
This is a second signal processor that demodulates an analog audio signal. 28 is a second output terminal to which the output signal of the second signal processor 27 is output; 29 is a second magnetic head group 21a, 2
1b and amplifies the signal supplied via the second rotary transformer 20 and the third switch 19. A demodulator 30 demodulates the output signal of the fourth amplifier 29 into a video signal and outputs it to the second output terminal 21.

and a first amplifier 11. first switch 12, first
Rotating transformer 13. First magnetic helix group 15 ae
15 bt The third amplifier 25 constitutes the first recording/reproducing means, and the second amplifier 18 . Second switch 18.
Second rotating transformer 20. Second magnetic head group 21
a, 21b, and a fourth amplifier 29 constitute a second recording/reproducing means.

The operation of the magnetic recording/reproducing apparatus in this embodiment configured as above will be described below.

First, the recording operation will be explained.

A digital signal conforming to the EIAJ digital audio interface standard inputted to the input terminal 1 is separated by the receiver 2 into a digital audio signal and additional information signals such as a copy prohibition flag and a sampling frequency flag.

The additional information signal is supplied to the copy prohibition detector 3 and the sampling frequency discriminator 4, and the digital audio signal is supplied to the first
switch 8 and D/A converter 6. The copy prohibition detector 3 detects whether the copy prohibition flag in the input additional information signal prohibits digital copying. If digital copying is prohibited, a high level control signal is output, and if it is not prohibited, a low level control signal is output. Further, the sampling frequency discriminator 4 discriminates whether the input digital audio signal has a sampling frequency compatible with the first signal processor 9 based on the sampling frequency flag in the input additional information signal. Then, if it is compatible, a high-level control signal is output, and if it is not compatible, a low-level control signal is output.

The digital audio signal supplied to the D/A converter 6 is converted into a two-channel analog audio signal. After that, A
In the /D converter 7, the signal is again digitized at a sampling frequency of 48 kHz, which allows signal processing by the first signal processor 9, and is output to the first switch 8.

The first switch 8 switches to the E side when the OR circuit 5 outputs a low level control signal and supplies the output signal of the receiver 2 to the first signal processor 9, and switches to the F side when the OR circuit 5 outputs a high level control signal. The output signal of the A/D converter 7 is then supplied to the first signal processor 8. In other words, if digital copying is prohibited or if a digital audio signal with a sampling frequency that cannot be recorded is input, the input digital audio signal is first exchanged with an analog signal and then digitized again with a recording sampling frequency. . The first signal processor 9 performs signal processing such as adding an error correction code and formatting the input digital audio data, and supplies the data to the first modulator 10 .

The first modulator 10 converts the input signal into a four-phase phase modulated signal having a carrier frequency of 2.5 MHz in the frequency band indicated by H in FIG. The signal amplified by the first amplifier 11 is sent to the first magnetic head with an azimuth angle of ±30° attached to the cylinder 14 via the second switch 12 switched to the R side and the first rotary transformer 13. Group 15a.

15b. Note that the first magnetic head group 15a,
15b is attached around the cylinder 14 at a positional relationship of 180 degrees.

The video signal applied to the second input terminal 16 is input to the second modulator 17, and after being separated into a luminance signal and a color signal,
The signals are frequency modulated and low-pass converted into the frequency bands shown in FIG. 2, respectively. The frequency modulated luminance signal and the low frequency converted chrominance signal are added and supplied to the second amplifier 18.

The signal amplified by the second amplifier 18 is transferred to the third switch 19 switched to the R side and the second rotary transformer 2.
The azimuth angle attached to the cylinder 14 through 0 ±
6° second magnetic head group 21a, 21b. Note that the second magnetic heads 21a and 2tb are connected to the cylinder 1.
It is attached around 4 in a 180 degree positional relationship.

The cylinder 14 has guide posts 23 a and 23 b.
The magnetic tape 22 is wound diagonally and runs in the direction of arrow B shown in FIG. At the same time, the cylinder 14 is controlled by the control device 24 and rotates in the direction of arrow A.
The respective signals are recorded on the magnetic tape 22 in tracks diagonal to the running direction of the magnetic tape. The magnetic head groups attached to the cylinder 14 are arranged so that the recorded tracks overlap, that is, the tracks recorded by the first magnetic head groups 15a and 15b are later overlapped by the second magnetic head groups 21a and 21b. The height is determined as follows.

That is, the magnetic heads 15a and 15b are mounted at the same height, and the magnetic heads 21a+21b are mounted at the same height but lower than the magnetic head 15a.

The track pattern recorded on the magnetic tape 22 in this manner is shown in FIG. 10 shown in Figure 3
1 a, 10 l b, 102 a, 10
2 b are magnetic heads 15 al 15 b, respectively.
+21 a.

This is the track recorded by 21b.

Although the tracks recorded on the magnetic tape 22 overlap each other, since the azimuth angles of the magnetic heads are different, signals recorded by magnetic heads having different azimuth angles are attenuated by azimuth loss during reproduction.

In addition, the carrier wave frequency is selected so that parts of high signal energy do not overlap each other in the frequency band of the signal recorded by the Do group for each magnetic field. As a result, mutual interference can be reduced, and even if recording tracks overlap, the degree of attenuation of previously recorded signals can be reduced.

The playback operation will be described.

The signals reproduced by the first magnetic head group 15a, 15b are applied to the third amplifier 25 via the first rotary transformer 13 and the second switch 12 switched to the P side, and are amplified. . First magnetic head group 15
The signals reproduced from the signals a and 15b are demodulated into digital signals by a first demodulator 26. The second signal processor 27 performs various signal processing on this digital signal, demodulates it into an analog audio signal, and outputs it to the first output terminal 28 .

The signals reproduced by the second magnetic head group 21a, 21b are applied to the fourth amplifier 29 via the second rotary transformer 20 and the third switch 19 switched to the P side, and are amplified. The signal amplified by the fourth amplifier 29 is demodulated into a video signal by the second demodulator and output to the second output terminal 31.

As described above, according to this embodiment, there are two groups of recording and reproducing means for recording and reproducing signals on a magnetic tape, and a digital audio signal from an input digital signal.

A receiver that extracts a copy prohibition flag and a sampling frequency flag, a digital/analog converter that converts the digital audio data output from the receiver into analog audio data, and a digital/analog converter that converts the output signal of the digital/analog converter into a digital audio signal. An analog/digital converter for conversion, a detector for detecting the copy prohibition flag output from the receiver, a discriminator for discriminating the sampling frequency flag output from the receiver, and an analog/digital converter for detecting the copy prohibition flag output from the receiver. An OR circuit that calculates a logical sum, and a switch that outputs either the digital audio signal output from the receiver or the digital audio signal output from the analog/digital converter based on the output signal of the OR circuit; a digital signal processor that adds an error correction code to the digital audio signal, and a first modulator that uses the output signal from the digital signal processor as a modulation input and supplies the modulated signal to the first recording/reproducing means. A second converter converts the input video signal into a frequency-modulated luminance signal and a low-frequency-converted color signal, and supplies the converted signals to a second recording/reproducing means.
Even if digital copying of the input digital signal is prohibited,
Even if a digital signal with an incompatible sampling frequency is input, recording of the video signal will not be hindered.

Note that in this embodiment, the first. As the second recording/reproducing means, a deep recording method was used in which magnetic heads having different azimuth angles were attached to a cylinder. but, "
Electronics Life” (August 1987 issue p47
- The first part is as shown in the 8mm video described on page 53).
As a recording and reproducing means, a method of recording and reproducing compressed signals on a magnetic tape area with increased winding angles may be used. Further, the modulation performed by the first modulator 60 may also use digital modulation and conversion such as pi-phase modulation and 8-10 conversion.

Effects of the Invention As described above, the present invention includes two groups of recording and reproducing means for recording and reproducing signals on a magnetic tape, and extracts a digital audio signal, a copy prohibition flag, and a sampling frequency flag from an input digital signal. a receiver, a digital/analog converter that converts digital audio data output from the receiver into analog audio data, an analog/digital converter that converts an output signal of the digital/analog converter into a digital audio signal, and a receiver. a detector for detecting a copy prohibition flag output from the receiver; a discriminator for discriminating the sampling frequency flag output from the receiver; an OR circuit for calculating the logical sum of the output signals of the detector and the discriminator; Depending on the output signal of the circuit, there is a switch that outputs either the digital audio signal output from the receiver or the digital audio signal output from the analog/digital converter, and an error correction code is applied to the digital audio signal output from the switch. a digital signal processor that performs addition, etc., a first modulator that takes the output signal from the digital signal processor as a modulation input and supplies the modulated signal to the first recording and reproducing means, and the input video signal, After converting into a frequency modulated luminance signal and a low frequency converted color signal, the second
By providing a second modulator that supplies data to the recording and reproducing means, even when digital copying of digital signals is prohibited or when a digital signal with an incompatible sampling frequency is input, , without interfering with the recording of video signals.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a magnetic recording/reproducing apparatus according to an embodiment of the present invention, FIG. 2 is a frequency band diagram of signals recorded on a magnetic tape, FIG. 3 is a track pattern diagram of a magnetic tape, and FIG. 4 is a diagram of a conventional magnetic recording/reproducing apparatus. FIG. 1 is a block diagram of a magnetic recording/reproducing device. 2...Receiver, 3...Copy protection detector,
4...Sampling frequency discriminator, 5...OR
Circuit, 6...D/A converter, 7...A/D converter, 8°12.19...Switch, 9.27...
・Signal processor, 10.17...Modulator, 28.3
0... Demodulator.

Claims (1)

[Claims] First and second recording and reproducing means for recording and reproducing signals on a magnetic tape; receiving a digital signal inputted through a digital interface; and generating digital audio data, a copy prohibition flag and a sampling frequency from the input signal a receiver that extracts a flag; a digital/analog converter that converts the digital audio data output from the receiver into analog audio data; and an analog/analog converter that converts the output signal of the digital/analog converter into a digital audio signal. a digital converter; a detector for detecting a copy prohibition flag output from the receiver; a discriminator for discriminating a sampling frequency flag output from the receiver; and an output signal of the detector and the discriminator. an OR circuit that performs a logical sum; a switch that outputs either a digital audio signal output from the receiver or a digital audio signal output from the analog/digital converter according to the output signal of the OR circuit; a digital signal processor that adds an error correction code to the digital audio signal output from the switch; and a digital signal processor that uses the output signal from the digital signal processor as a modulation input and supplies the modulated signal to the first recording and reproducing means. a first modulator that converts the input video signal into a frequency-modulated luminance signal and a low-band-converted color signal, and then supplies the converted signals to the second recording/reproducing means; A magnetic recording/reproducing device comprising: