JP2572833B2 - PCM recording / reproducing device with built-in BS tuner - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a PCM recording / reproducing apparatus with a built-in BS tuner for digitally recording a digital audio signal.

[Prior Art] FIG. 3 is a block diagram showing a recording system of a conventional recording / reproducing apparatus with a built-in BS tuner. In FIG. 3, (10) is an external video signal input terminal, and (11) is a video signal input switching. Switch, (12) is a low-pass filter (hereinafter referred to as LPF) for extracting luminance signal from video signal, (13) is FM modulation circuit, (14) is for extracting chromaticity signal from video signal (15) is a frequency conversion circuit for low-frequency conversion, (16) is a video signal recording amplifier, and (17) is a video signal head.

(18) is the RF signal input terminal, (19) is the RF converter,
(20) is a tuner, (21) is a BS signal input terminal, (22) is
BS converter, (23) BS tuner, (24) 4-phase differential phase demodulation circuit of audio subcarrier (hereinafter referred to as QPSK demodulation circuit), (25) PCM data demodulation circuit, (26) digital filter, (27) is a D / A converter, (28) is an LPF,
(49) is a magnetic tape, (50) is an external analog audio signal input terminal, (51) is an audio signal input switch, (52) is
FM modulation circuit, (53) is an analog audio signal recording amplifier,
(54) is an analog audio signal head.

FIG. 4 is a block diagram showing a reproducing system of a conventional recording / reproducing apparatus with a built-in BS tuner. In FIG. 4, (17) is a video signal head, (49) is a magnetic tape, and (54) is an analog audio signal. Head for signal, (55) amplifier for video signal reproduction,
(56) is a BPF for extracting a luminance signal, (57) is an FM demodulation circuit, (58) is an LPF for extracting a chromaticity signal, (5)
9) is a frequency conversion circuit for returning the low-frequency converted signal, (60) is a video signal output terminal, (65) is an amplifier for reproducing analog audio signals, (66) is an FM demodulation circuit, and (67) Is an analog audio signal output terminal.

 Next, the operation of the above configuration will be described.

First, the recording operation will be described. The analog audio signal input from the external analog audio signal input terminal (50) and the RF signal input from the RF signal input terminal (18) pass through the RF converter (19) to the tuner (20). ) And the analog audio signal selected from the BS signal input terminal (21)
The BS signal passes through the BS converter (22), demodulates the audio subcarrier selected by the BS tuner (23) by the QPSK demodulation circuit (24), and converts it into digital audio data by the PCM data demodulation circuit (25). The audio signal input switch (51) is used to perform the arithmetic operation in the filter (26), convert it to an analog signal in the D / A converter (27), and remove the high-frequency component in the LPF (28). Are modulated by the FM modulation circuit (52), and are recorded in the deep layer of the magnetic tape (49) by the analog audio signal head (54) via the analog audio signal recording amplifier (53).

On the other hand, the video signal input from the external video signal input terminal (10) and the RF signal input from the RF signal input terminal (18) pass through the RF converter (19) and the video signal selected by the tuner (20). The video signal input switch (11) is used to switch the signal input from the BS signal input terminal (21) via the BS converter (22) to the video signal selected by the BS tuner (23).
The luminance signal is extracted by the LPF (12) and the chrominance signal is extracted by the BPF (14). The luminance signal is modulated by the FM modulation circuit (13), and the chrominance signal is converted by the frequency conversion circuit (15).
After the low-frequency conversion, the two signals are added to each other, and are passed through a video signal recording amplifier (16) to the analog audio signal head (54) and the video signal head (17) having a different azimuth angle using a magnetic tape (17). 49) recorded on the surface layer.

Next, the reproducing operation will be described. The video signal recorded on the magnetic tape (49) is transferred to the video signal head (17).
And the BPF (5) via the video signal playback amplifier (55).
The luminance signal component is extracted in 6), and the chromaticity signal component is extracted in LPF (58). The converted data is restored, the two are added, and the result is output to the video signal output terminal (60).

On the other hand, the audio signal is reproduced by the analog audio signal head (54), and is passed through the analog audio signal reproduction amplifier (65).
The signal is demodulated by the FM demodulation circuit (66) and output to the analog audio signal output terminal (67).

[Problem to be Solved by the Invention] Since the conventional recording / reproducing apparatus with a built-in BS tuner is configured as described above, the digital audio signal from the BS tuner cannot be directly recorded on the magnetic tape. Therefore, there is no external digital audio signal input terminal.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and a digital audio signal from a BS tuner and an external digital audio signal can be input and recorded and reproduced by sharing an interface. An object of the present invention is to provide a PCM recording / reproducing apparatus with a built-in BS tuner.

Means for Solving the Problems In order to achieve the above object, the present invention provides a means for incorporating a BS tuner and an RF tuner for recording and reproducing a video signal on a magnetic tape surface layer, Means for recording / reproducing an analog audio signal to / from the deep magnetic tape with an azimuth angle different from that for recording / reproducing.
A PCM recording / reproducing device, which demodulates a BS audio signal output from the BS tuner, converts the demodulated BS audio signal into the analog audio signal, and outputs the analog audio signal. PCM demodulation for performing PCM demodulation on the BS audio signal A BS audio signal demodulating means including a circuit, a BS digital audio signal branched out and taken out after the PCM demodulation, and an external digital audio signal inputted from outside as a PCM audio signal are selectively passed through the first digital audio signal.
A first digital audio signal switching circuit for outputting a digital audio signal, and an A / D for performing A / D conversion on at least an externally input analog audio signal and outputting this as a second digital audio signal A conversion circuit, a second digital audio signal switching circuit for selecting and outputting either the first digital audio signal or the second digital audio signal, and a second digital audio signal switching circuit selected by the second digital audio signal switching circuit. A digital audio signal recording circuit for recording the digital audio signal together with the analog audio signal in the deep layer of the magnetic tape; and a digital audio signal reproducing circuit for reproducing the digital audio signal recorded on the magnetic tape. Digital recording or digital recording of external analog audio signal is selected and performed. It is.

[Action]

According to the above configuration, the BS audio signal from the BS tuner is
The digital signal is sent to the audio demodulation means, and the BS digital audio signal is branched and taken out from the PCM demodulation circuit included in the audio demodulation means.
One of a digital audio signal and an external digital audio signal input from the outside is selected by a first digital audio signal switching circuit, and the first digital audio signal is selected by a second digital audio signal switching circuit. A second digital audio signal obtained by A / D conversion of an analog audio signal input from the outside is selected, and the selected digital audio signal is processed by the digital audio signal recording circuit together with the analog audio circuit. It is recorded in the deep layer of the magnetic tape. On the other hand, a digital audio signal recorded on a magnetic tape is reproduced by a digital audio signal reproducing circuit, so that not only recording and reproduction of video signals and analog audio signals but also recording and reproduction of digital audio signals are combined. Can be done. In this case, the BS digital audio signal and the external digital audio signal can be freely selected and recorded.

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

FIG. 1 shows a PC with a built-in BS tuner according to an embodiment of the present invention.
FIG. 3 is a block diagram showing a recording system of the M recording / reproducing apparatus, in which (10) is an external video signal input terminal, (11) is a video signal input switching switch, and (12) extracts a luminance signal from the video signal. LPF for (13) FM modulation circuit, (14)
Is a BPF for extracting chromaticity signals from video signals, (15)
Is a frequency conversion circuit for low-frequency conversion, (16) is a video signal recording amplifier, and (17) is a video signal head.

(18) is the RF signal input terminal, (19) is the RF converter,
(20) is a tuner, (21) is a BS signal input terminal, (22) is
BS converter, (23) BS tuner, (24) QPSK demodulation circuit of voice subcarrier, (25) PCM data demodulation circuit, (2)
6) is a digital filter, (27) is a D / A converter,
(28) is the LPF.

(29) is an external analog audio signal input terminal, (30) is an analog audio signal input switch, (31) is LPF, (3)
2) is a sample and hold circuit (hereinafter referred to as S / H circuit),
(33) is an A / D converter, (34) is a digital audio data switching switch, (35) is a memory, (36) is a memory address control circuit, (37) is an error correction code encoding circuit, and (38) is QPSK. Modulation circuit, (39) Digital audio signal recording amplifier, (40) Head for digital audio signal, (41) External digital audio signal input terminal, (42)
Is a digital audio signal input switch, (43) is a serial / parallel conversion circuit (hereinafter referred to as S / P circuit), (44) is a phase detection circuit, (45) is a VCO, and (46) is a data timing clock. Generation circuit, (47) Data latch circuit, (48)
Indicates a parallel / serial conversion circuit (hereinafter referred to as P / S circuit), (4
9) is a magnetic tape.

FIG. 2 shows a PC with a built-in BS tuner according to an embodiment of the present invention.
FIG. 3 is a block diagram showing a reproducing system of the M recording / reproducing apparatus, in which (17) is a head for a video signal, (26) is a digital filter, (27) is a D / A converter, and (28) is an LP.
F, (35) is a memory, (36) is a memory address control circuit, (40) is a head for digital audio signals, (4
9) is a magnetic tape.

(55) is an amplifier for reproducing a video signal, (56) is a BPF for extracting a luminance signal, (57) is an FM demodulation circuit, (58) is an LPF for extracting a chromaticity signal, and (59) is low. A frequency conversion circuit for restoring the band-converted signal, (60) is a video signal output terminal, (61) is a digital audio signal reproduction amplifier, (62) is a QPSK demodulation circuit, and (6) is an error correction code. The decoding circuit (64) is an analog audio signal output terminal.

 Next, the operation of the above configuration will be described.

First, the recording operation will be described. The signal input from the BS signal input terminal (21) passes through the BS converter (22).
The audio subcarrier selected by the BS tuner (23) is demodulated by the QPSK demodulation circuit (24), and the PCM data demodulation circuit (25)
The digital audio signal demodulated by the digital audio signal input terminal (41) and the digital audio signal input from the external digital audio signal input terminal (41) are selected by the digital audio signal input switch (42), and the phase of the data is detected by the phase detection circuit (44). ) To detect
The VCO (45) is controlled, and the data timing clock is generated by the timing clock generation circuit (46).
The data that has been S / P converted by the S / P conversion circuit (43) is latched by the data latch circuit (47), and only the digital audio data is
P / S conversion is performed by a P / S conversion circuit (48), and the converted data is transmitted to a digital audio data switching switch (34).

The digital audio signal demodulated by the PCM data demodulation circuit (25) is further processed by a digital filter (26), converted to an analog signal by a D / A converter (27), and converted to an analog signal by an LPF (28). An analog audio signal from which components have been removed, a signal input from an RF signal input terminal (18), an analog audio signal selected by a tuner (20) via an RF converter (19), and an external analog signal input terminal (29) An analog audio signal input from the A / D converter (32) is selected by an analog audio signal input switch (30) and a noise component is removed by an LPF (31). ) Is converted to digital audio data and sent to the digital audio data switching switch (34). The data selected by the digital audio data switching switch (34) is stored in the memory (35) according to the instruction of the memory address control circuit (36). The data in the memory (35) is read out by a memory address control circuit (36) in accordance with a certain rule, and is coded for error correction by an error correction code coding circuit (37). ). After that, the data in the memory (35) is read out at any time by the memory address control circuit (36), modulated by the QPSK modulation circuit (24), and then read through the digital audio signal recording amplifier (39). The sound signal head (40) is used to record the data to the depth of the magnetic tape (49).

On the other hand, the video signal input from the external video signal input terminal (10) and the RF signal input from the RF signal input terminal (18) pass through the RF converter (19) and the video signal selected by the tuner (20). The signal input from the BS signal input terminal (21) passes through the BS converter (22) and the video signal selected by the BS tuner (23) to the video signal input switch (11).
The luminance signal is extracted by the LPF (12) and the chrominance signal is extracted by the BPF (14). The luminance signal is modulated by the FM modulation circuit (13), and the chrominance signal is converted by the frequency conversion circuit (15).
After the low-frequency conversion is performed, the two are added, and the digital audio signal head (40) and the video signal head (17) having different azimuth angles are added via the video signal recording amplifier (16).
Is recorded on the surface layer of the magnetic tape (49).

Next, the reproducing operation will be described. The video signal recorded on the magnetic tape (49) is converted to a video signal head (17).
BPF via the video signal playback amplifier (55)
A luminance signal component is extracted in (56), and a chromaticity signal component is extracted in LPF (58). Among them, the luminance signal component is demodulated by the FM demodulation circuit (57), and the chrominance signal is low-frequency converted by the frequency conversion circuit (59). 60) is output.

The digital audio signal is reproduced by the digital audio signal head (40), is demodulated by the QPSK demodulation circuit (62) via the digital audio signal reproduction amplifier (61), and is instructed by the memory address control circuit (36). Stored in memory (35). The data in this memory (35)
The memory address control circuit (3
The data is read out in 6), decoded for error correction in the error correction code decoding circuit (63), and written to the memory (35). After that, the data in the memory (35) is read out at any time by the memory address control circuit (36),
The analog audio signal calculated by the digital filter (26), converted to an analog signal by the D / A converter (27), and the high-frequency component removed by the LPF (28) is output from the analog audio signal output terminal (64). Is output.

In the above-described embodiment, the recording and reproduction using the rotating head has been described. However, the recording and reproduction may be performed linearly in the longitudinal direction of the magnetic tape using the fixed head.

Further, the input signal at the time of recording does not necessarily have to be input to both the video signal and the digital audio signal.

[Effects of the Invention] As described above, according to the present invention, in addition to recording / reproducing a video signal and an analog audio signal, recording / reproduction of a digital audio signal can be performed together. In this case, the BS digital audio signal and the external digital audio signal can be freely selected and recorded. In addition, 1
A set of audio heads can record both analog and digital audio signals. Further, since the digital audio signal is recorded in the deep layer of the magnetic tape together with the analog signal, the recording area in the thickness direction of the magnetic tape can be increased, and the quality of the recording signal can be improved.

[Brief description of the drawings]

FIG. 1 shows a PCM with a built-in BS tuner according to an embodiment of the present invention.
FIG. 2 is a block diagram showing a recording system of a recording / reproducing apparatus, FIG. 2 is a block diagram showing a reproducing system of a PCM recording / reproducing apparatus with a built-in BS tuner according to an embodiment of the present invention, and FIG. FIG. 4 is a block diagram showing a recording system, and FIG. 4 is a block diagram showing a reproducing system of a conventional recording / reproducing apparatus with a built-in BS tuner. (21) BS signal input terminal, (22) BS converter,
(23)… Tuna, (25)… PCM data demodulation circuit,
(39)… Digital audio signal recording amplifier, (40)…
Head for digital audio signal, (41) External digital audio signal input terminal, (42) Digital audio signal input switch, (49) Magnetic tape. The same reference numerals in the drawings indicate the same or corresponding parts.

Claims (1)

(57) [Claims] A means for incorporating a BS tuner and an RF tuner for recording / reproducing a video signal on a surface layer of a magnetic tape;
Means for recording / reproducing an analog audio signal in a deep layer of the magnetic tape with a different azimuth angle from the recording / reproduction of the video signal, wherein the BS audio output from the BS tuner is provided. A BS audio signal demodulating means including a PCM demodulation circuit for performing PCM demodulation on the BS audio signal, which is a circuit for converting the analog audio signal to the analog audio signal and outputting the signal after demodulating the signal; A first digital audio signal switching circuit for selectively passing a BS digital audio signal to be taken out and an external digital audio signal externally input as a PCM audio signal and outputting a first digital audio signal; A / A for analog signals input from outside
A / D that performs D conversion and outputs a second digital audio signal
A conversion circuit; a second digital audio signal switching circuit for selecting and outputting either the first digital audio signal or the second digital audio signal; and a second digital audio signal switching circuit selected by the second digital audio signal switching circuit. A digital audio signal recording circuit for recording the digital audio signal together with the analog audio signal in a deep layer of the magnetic tape; and a digital audio signal reproducing circuit for reproducing the digital audio signal recorded on the magnetic tape. A PCM recording / reproducing apparatus with a built-in BS tuner, which can select and record either digital recording of a signal or digital recording of an external analog audio signal.