JPS62185249A - Recording and reproducing device for digital signal - Google Patents

Abstract

PURPOSE:To execute a dubbing operation of a digital signal, and to curtail remarkably a circuit scale for recording and reproduction, by providing a circuit system used for both recording and reproduction of a digital signal, and switching and connecting it suitably by a switching circuit. CONSTITUTION:The titled device is provided with a low-pass filter 22 for limiting a band, a signal converter 23 for executing an A/D conversion or a D/A conversion, a digital processing circuit 24, a modulating and demodulating circuit 25, the first recording amplifier 26, a reproducing amplifier 27, a reproducing equalizer 28, a clock reproducing circuit 29, a data detector 30, the second recording amplifier 31, the first tape running mechanism 32, the second tape running mechanism 35, the first switching circuit SW1, and the second switching circuit SW2. In this way, a digital signal which has been reproduced from a magnetic tape of the first tape running mechanism side can be recorded, namely, dubbed to a magnetic tape of the second tape running mechanism side through a data detector, and a circuit scale for digital recording and reproduction can be curtailed remarkably.

Description

[Detailed Description of the Invention] (a) Field of Industrial Application The present invention relates to a digital signal recording and reproducing device that converts an audio signal into a digital signal and records it on a magnetic tape, and particularly relates to a digital signal recording and reproducing device for converting an audio signal into a digital signal and recording it on a magnetic tape. The present invention relates to a digital signal recording and reproducing apparatus that includes a plurality of tape running mechanisms and performs signal dubbing.

(b) Conventional technology audio signal yg-P CM (Pu1se Code M
A tape recorder that converts into a signal (duration) and records and plays it has an input terminal (1) as shown in Figure 2.
The input analog signal is passed through a low-pass filter (2)
After the signal is band-limited by the A/D converter (3), it is converted into a PCM signal. This PCM signal is processed by the digital processing circuit (
In step 4), after processes such as adding an error correction code to correct signal errors due to signal dropouts during reproduction and adding a synchronization signal to represent the beginning of a digital data block are performed, the modulation circuit ( The recording system (R1) is configured such that the signal is converted into a signal that can be easily recorded and reproduced on the magnetic tape by 5), the power is amplified by the recording amplifier (6), and the signal is recorded on the magnetic tape (8) by the recording head (7). ing.

During playback, the signal read out from the magnetic tape (8) by the playback head (9) is voltage amplified by the playback amplifier (IG), and then the characteristics of the recording and playback system such as the head and tape are compensated by the playback equalizer αB. The signal is then converted into the original recording digital signal by a data detection circuit. α3 is a clock regeneration circuit, which reproduces the glow signal for data detection that follows the signal containing jitter such as rotational unevenness. At the detection circuit, data is detected based on the clock regenerated by the clock regeneration circuit, then demodulated to the original PCM signal by the demodulation circuit αa, and synchronized signals are detected and errors are corrected by the digital processing circuit. After the D/A
A reproduction system tp+ is configured such that the signal is restored to the original analog signal by a converter α01 and a low-pass filter αη and outputted from an output terminal (181).

As for the mechanism for running the magnetic tape, a fixed head type or a rotating head type is used (for example, JP-A-59-162606'5!r, JP-A-59-162606'5!r).
92411% publication).

By the way, in order to realize a signal dubbing function, a conventional analog audio tape recorder is equipped with two tape running mechanisms, and the first tape running mechanism performs Q1.
A method has been adopted in which the second tape running mechanism records the reproduced signal at the same time that 0 is reproduced.

In such a configuration having two tape running mechanisms (hereinafter referred to as a double-deck configuration), in order to shorten the time required for dubbing, the tape running speed of the recording tape running mechanism and the reproducing tape running mechanism is simultaneously increased, for example, from 2 to 2.
It can speed up 6 times and shorten dubbing time to 1/2 to 1/6.

1"l Problems to be Solved by the Invention Let us consider the case where this double-deck configuration for ignition is applied to the aforementioned digital ε recording/playback system tape recorder.

In order to function as a double-deck configuration, at least the recording system i and the playback system [F
] must be provided separately. On the other hand, the recording and playback circuit of a digital recording and playback type tape recorder is
The circuit scale is larger than that of a conventional analog recording/playback system tape recorder, and the aforementioned recording system and playback system (
If both of these are provided, a problem arises in that the cost becomes high.

(-4 Means for Solving Problems) In view of the above problems, the present invention provides a low-pass filter for band limiting, a signal converter for performing A/D conversion or D/A conversion, and a signal converter for encoding or converting digital data. a digital processing circuit for decoding, a modulation/demodulation circuit for modulating or demodulating digital data, a first epsilon amplifier for amplifying the modulated signal of the circuit, a regenerative amplifier, and a regenerative equalizer for compensating the characteristics of the output of the regenerative amplifier; a clock regeneration circuit that regenerates a clock from the equalizer output signal; and a clock regeneration circuit that detects data from the equalizer output signal based on the clock regenerated by the clock regeneration circuit and uses the data as data for demodulation of the modulation/demodulation circuit. a first recording/reproducing head; a second recording amplifier for amplifying the data detector output signal; and a first recording/reproducing head.
A tape running mechanism, a second tape running mechanism including a second recording/reproducing head, and the first recording/reproducing head are connected to the @
11 a first switch circuit connected to the output side of the recording amplifier or the input side of the regenerative amplifier; and a second switch circuit connected to the second recording/reproducing head to the output side of the second recording amplifier or the input side of the regenerative amplifier. The present invention provides a digital signal recording and reproducing device equipped with a switch circuit.

(e) Operation: The first recording/reproducing head of the first tape traveling mechanism is connected to the input side of the reproducing amplifier by the first switch circuit, and the second recording/reproducing head of the m2 tape traveling mechanism is connected by the @2 switch circuit. is connected to the output side of the second recording amplifier, the digital signal reproduced from the magnetic tape on the side of the first tape traveling mechanism is recorded on the magnetic tape on the side of the second tape traveling mechanism through the data detector, i.e. Can be dubbed.

(F) Embodiment An embodiment of the main apparatus for recording and reproducing digital signals according to the present invention will be described with reference to FIG.

In Figure 1, l is an analog signal input terminal, ■ is an analog playback signal output terminal, the reason is a recording/playback switching signal input terminal for switching the circuit operation to recording or playback, and ■ is a low pass shared during recording and playback. The filter is a signal converter that performs A/D conversion or D/A conversion, (to) is a digital processing circuit that encodes or decodes digital data, and (c) is a modulation/demodulation circuit that modulates or demodulates digital data. These low-pass filters and the digital processing circuit-1 modulation/demodulation circuit (5) of the signal converter are switched to recording system operation or reproducing system operation by the signal from the switching signal input terminal (2).

(to) is the first recording amplifier that amplifies the modulation signal of the modulation/demodulation circuit (5), (2) is the regenerative amplifier, (2) is the regenerative equalizer that compensates the characteristics of the output of the regenerative amplifier, and is the equalizer that uses the output signal of the equalizer. a clock regeneration circuit that regenerates a clock; (2) a data detector that detects data from the equalizer output signal based on the clock regenerated by the clock regeneration circuit and uses the data as data for demodulation in the modulation/demodulation circuit; 01) is a second recording amplifier that amplifies the data detector output signal, and (to) is a first recording amplifier.
A first tape running mechanism in which a recording/reproducing head (to) and a first magnetic tape (to) are prepared; The traveling mechanism (SWr) is the first recording/reproducing head (to)
A first switch circuit (SWz) connects the second recording/reproducing head (to) to the output side of the first recording amplifier C31 or the input side of the reproducing amplifier C31).
or the input side of the regenerative amplifier ■.
It is a switch circuit.

(to) is a control input terminal to which a control signal for switching the first switch circuit (SWl) and the second switch circuit (SWz) is input.

Therefore, if a dubbing control signal is input to the control input terminal (to), which sets the first tape traveling mechanism (to) to the playback mode and sets the second tape traveling mechanism (to) to the recording mode, the dubbing control signal is input to the control input terminal (to). One switch circuit (SW θ connects the first recording/reproducing head (to) to the input side of the reproducing amplifier surface, and the second switch circuit (SWs) connects the first recording/reproducing head (to) to the input side of the reproducing amplifier surface.
is connected to the output side of the second recording amplifier 6D,
At the same time, the signal from the recording/reproduction switching signal input terminal (2) switches the low-pass filter, signal converter (to), digital processing circuit (2), and modulation/demodulation circuit (c) to reproduction system operation.

As a result, the signal read out by the first recording/reproducing head (to) is amplified by the reproducing amplifier surface, and the reproduction amplifier (to)
After the characteristics are compensated by the data detector ω based on the recovered clock of the clock recovery circuit, the digital data is amplified by the second recording amplifier C3]
The information is recorded on the second magnetic tape (b) of the second tape running mechanism (b) by the recording/reproducing head (b), and so-called dubbing is performed. At the same time, the data from the data detector (2) is outputted from the output terminal (2) as an original analog signal by the demodulation circuit (C), the decoding circuit (C), the low-pass filter of the D/A converter.

Incidentally, the normal ε recording operation and reproduction operation can be executed by appropriately switching the first switch circuit (SW θ) using a control signal from the control input terminal (to).

(G) According to the present invention, as described in detail, a set of circuit systems for recording and reproducing digital signals is prepared, and in addition to this, a simple second recording amplifier is added, Since the dubbing operation of a digital signal can be performed simply by appropriately switching connections using a switch circuit, it is possible to significantly reduce the circuit scale for digital recording and reproduction using a double-deck configuration, which is useful.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a digital signal recording and reproducing apparatus according to the present invention, and FIG. 52 is a block diagram showing a conventional example of a digital recording and reproducing type tape recorder. ■...Low pass filter, ■...Signal converter, (to)...Digital processing circuit, ■...Modulation/demodulation circuit, (4
)...First recording amplifier,...Reproducing amplifier, (support)
... Regenerative equalizer, device... Clock regeneration circuit, ■...
・Data detector, C3])...Second recording amplifier, (
2)...First tape running mechanism, (To)...First recording/reproducing head, (7)...Second tape running mechanism, (To)
...Second ξ recording/playback head, (SWl)...first switch circuit, (SW2)...second switch circuit.

Claims (1)

[Claims] (1) A low-pass filter for band limiting, a signal converter that performs A/D conversion or D/A conversion, a digital processing circuit that encodes or decodes digital data, and a modulation/demodulation circuit that modulates or demodulates digital data; a first recording amplifier that amplifies the modulation signal of the circuit; a reproducing amplifier;
a regenerative equalizer that compensates the characteristics of the regenerative amplifier output; a clock regeneration circuit that regenerates a clock from the equalizer output signal; and a clock regeneration circuit that regenerates a clock from the equalizer output signal based on the clock regenerated by the clock regeneration circuit. a data detector that detects the data and uses the data as data for demodulation of the modulation/demodulation circuit, a second recording amplifier that amplifies the output signal of the data detector, and a first tape running mechanism provided with a first recording/reproducing head. , second
a second tape running mechanism provided with a recording and reproducing head; a first switch circuit that connects the first recording and reproducing head to the output side of the first recording amplifier or the input side of the reproducing amplifier; and the second recording and reproducing head. A digital signal recording and reproducing apparatus, comprising: a second switch circuit that connects a head to an output side of the second recording amplifier or an input side of the reproducing amplifier.