JP2536343B2 - Digital recording / playback device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital recording / reproducing apparatus such as DAT.

[0002]

2. Description of the Related Art A receiver P receives a digital input signal during recording.
If the LL (Phase Locked Loop) is unlocked, it must be muted immediately and the recording interrupted to prevent noise recording. When the PLL lock is released, for example, the sampling frequency of the digital sound signal output from the BS tuner or the like differs depending on the mode. Therefore, when the mode is switched, the sampling frequency changes and the signal is interrupted, so that the PLL circuit of the digital recording / reproducing apparatus is unlocked. When the lock of the PLL circuit is released, the recorded signal has a non-predetermined format, which becomes noise and is recorded on the tape. Therefore, it is necessary to stop the recording immediately when the PLL lock is released, but in reality, the stop timing is not in time and a noise portion is generated on the tape. Therefore, when recording is stopped, rewinding is performed until just before the noise portion by review, and the position is set to P.
Recording was performed as a recording start position of a new signal after relocking of the LL circuit, and the noise portion was removed.

[0003]

However, in the rewinding operation just before the noise portion after relocking the PLL circuit as described above, the position accurately determined by the frame address of the signal terminating portion is detected. It is not done by. Therefore, the start position when recording a new signal is ambiguous, so when resuming recording, the rear part of the useful signal already recorded is erased, or the noise part remains. there were. The present invention solves the above-mentioned problems, and while recording a digital signal on a recording medium, the frame address at the position where the PLL lock is released and the recording is stopped is read by rewinding the frame address by reviewing, and this is stored, When a signal is recorded after returning to the PLL lock state again, a new signal is recorded when the frame address read by reproduction matches the previously stored frame address, so that the signal is already recorded. Without losing a useful signal, and
It is an object of the present invention to provide a digital recording / reproducing device capable of removing noise.

[0004]

In order to achieve the above object, the present invention has a PLL circuit, a receiving section for receiving a digital signal, and a signal processing section for processing the signal received by the receiving section. , In a digital recording / reproducing apparatus for recording the signal processed by the signal processing unit on a recording medium,
When the LL lock is released, recording is stopped, and a reading unit that reads the recording signal while rewinding the recording medium in the review, a storage unit that stores the frame address of the terminal end of the signal recording unit at the time of this reading, and the frame address After a lapse of a short time after reading, the stopping means for stopping the rewinding of the recording medium, and the reproduction start when the rewinding is stopped and the PLL lock state is restored,
A recording control means for starting recording when the frame address on the recording medium read by the reading means matches the frame address stored in the storage means.

[0005]

According to the above construction, when a digital signal such as a music signal is being recorded on a recording medium such as a tape and the PLL circuit is unlocked due to a change in the sampling frequency or the like, the recording is stopped by the reading means. Then, the tape is rewound by the review, and the frame address of the end portion of the already recorded music signal portion is read. This rewinding operation is stopped by the stopping means after a short time has elapsed after reading the frame address. Here, PL again
When the L-lock state is restored, reproduction is started to read the frame address, and when the read frame address matches the frame address previously stored in the storage means, the recording control means starts recording.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A DAT system according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the functional block configuration of this system. In the figure, the DAT main body 1 has a digital receiver 3 for receiving a digital audio signal from the BS tuner 2. Also, DA
The T body 1 is provided with a PLL circuit 4 that tunes the frequency of the digital audio signal received by the digital receiver 3. The PLL circuit 4 is unlocked when the sampling frequency of the digital audio signal changes, and enters the locked state again when a new frequency signal can be input. Further, the CPU 5 controls the entire DAT main body 1 according to a predetermined program procedure, and particularly controls the mechanism of the servo LSI 11 and the like which will be described later.

The DSP 6 inputs a digital audio signal,
The PLL circuit 4 performs signal processing such as error correction of the signal.
It is controlled by the clock generated in. The D / A converter 7 converts the digital signal processed by the DSP 6 into an analog signal and outputs it to the outside. The RF AMP 8 modulates the digital signal from the DSP 6 during signal recording, and the signal is recorded on the tape 10 (recording medium) by the drum head 9. Further, the RFAMP 8 demodulates the digital signal read from the tape 10 during reproduction. Servo LSI
Reference numeral 11 denotes a circuit that locks a capstan motor 12 that drives a capstan (not shown) of the DAT body 1 and a drum motor 13 that drives the drum 9 under the control of the CPU 5 when the PLL circuit 4 is locked. Where C
The PU 5, the DSP 6, the RF AMP 8, the drum head 9, the servo LSI 11, the capstan motor 12, and the drum motor 13 constitute a reading unit for reading a recording signal, a stopping unit, and a recording control unit, and the CPU 5 has a memory function and a storage unit. Built in.

Next, the signal recording operation by the DAT main body 1 of this embodiment will be described with reference to FIGS. 2 and 3. Figure 2
FIG. 3 is an explanatory diagram of a signal recording operation, and FIG. 3 is a diagram showing a tape recording state immediately after the PLL is unlocked and after the PLL is relocked. In these figures, when the sampling frequency changes during recording of the digital audio signal A, the PLL circuit 4 is unlocked (point b), and the CPU 5 stops recording (c
point). Since there is a slight time delay before the recording is stopped, a noise portion 22 (points b to c) is formed on the tape 10 between the signal A recorded portion 21 and the unrecorded portion 23. After the recording is stopped, the CPU 5 outputs an operation command to each section according to a predetermined program procedure, performs a review, and during the review operation, the signal A recorded section 21 is read by the reading means.
End, that is, the part (b
The frame address of point) is memorized.

Next, after storing the frame address, the review is stopped for a few hundred milliseconds, that is, at the point a. When it returns to the locked state, the play is started and the frame address on the tape 10 is read by the reading means. Then, when the read frame address matches the previously stored frame address, the recording control means starts recording a new digital audio signal B. As a result, the recording of the digital audio signal B is accurately restarted from the point b, which is the end of the signal A recorded section 21, so that the noise section 22 is completely erased by the signal B recording section 24, and the digital audio signal is recorded. A,
You can write and connect only B. It should be noted that the present invention is not limited to the configuration of the above embodiment, and various modifications can be made, and the present invention can be applied to a digital compact cassette (DCC) and other digital recording / playback devices.

[0010]

As described above, according to the present invention, during recording of a digital signal such as a music signal, the frame address of a position where the PLL lock is released due to a change in the sampling frequency of the signal and the recording is stopped is stored. , The recording start position of a new signal is determined based on the stored frame address, so that the rear part of the useful signal that has already been recorded is not erased, and the noise part is eliminated. It can be completely erased.

[Brief description of drawings]

FIG. 1 is a block diagram of a DAT body according to an exemplary embodiment of the present invention.

FIG. 2 is a diagram for explaining a signal recording operation by the DAT main body.

FIG. 3 is a diagram showing a signal recording state of the tape immediately after the PLL is unlocked and after the PLL is relocked.

[Explanation of symbols]

 3 Digital Receiver 4 PLL Circuit 5 CPU 6 DSP 8 RFAMP 9 Drum Head 10 Tape 11 Servo LSI 12 Capstan Motor 13 Drum Motor

Claims (1)

(57) [Claims] 1. A receiver having a PLL circuit for receiving a digital signal, a signal processor for processing the signal received by the receiver, and a signal processed by the signal processor recorded on a recording medium. In the digital recording and reproducing device
Recording is stopped when the PLL lock is released, and reading means for reading the recording signal while rewinding the recording medium in the review, storage means for storing the frame address of the terminal portion of the signal recording portion at the time of reading, and this frame address After a short time has elapsed after reading, the stop means for stopping the rewinding of the recording medium, and the reproduction start when the rewinding is stopped and the PLL lock state is restored, are read by the reading means. A digital recording / reproducing apparatus comprising: a recording control unit that starts recording when a frame address on a recording medium matches a frame address stored in the storage unit.