JPH0762940B2 - Playback device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a reproducing apparatus for reproducing a signal obtained by recording a wideband signal in multi-channels.

[Prior art]

Conventionally, as a method of recording a wide band signal, a high speed recording with a single channel (the relative speed between the head and the medium is large) and a low speed recording with a multi-channel by dividing the band (a relative speed between the head and the medium) are performed. Is small) is known to do. Among them, in the case of performing high-speed recording like the former, it is extremely difficult to maintain mechanical accuracy, and the deterioration of the head is remarkable, resulting in low reliability. Also, in the latter case, in order to perform low-speed recording,
It is improved compared to the former in maintaining mechanical accuracy and deterioration of the head, but it is necessary to keep the head alignment error between each channel within the allowable range. Need to

Further, in the reproducing system, the circuit for returning the signal of each channel to the original is complicated.

As described above, in any of the methods, the apparatus is required to have high accuracy, but it is actually difficult to remove the head alignment error and the mechanical error, and these errors cause a time error. When it occurs, there is a problem that the image quality is deteriorated. In addition, compatibility between the devices was also hindered.

〔Purpose〕

The present invention has been made in view of the above problems, and an object of the present invention is to provide a reproducing apparatus capable of improving the stability of image quality and reducing the system cost.

〔Example〕

First, a recording system circuit A of a wideband signal recording / reproducing apparatus according to the present invention will be described with reference to FIG.

The input information signal is subjected to predetermined signal processing by the preprocessing circuit 1 and then is processed by the multiplexer 2 into 2 channels CH1, CH.
It is divided into two signals and input to the signal processing circuits 3 and 4. Then, in the signal processing circuits 3 and 4, the information signal S of a form suitable for recording
It is converted into w (for example, FM modulated signal) and input to the adders 5 and 6. On the other hand, the system clock generation circuit 7 inputs the system clock required for multi-channel to the multiplexer 2 and the time reference signal generator 8, and the time reference signal St output from this signal generator 8 is added to the adder 5 , 6
Is entered. Then, the information signal Sw is added by the adders 9 and 10.
And the time reference signal St are added, and recording is performed on the recording medium from the heads 11 and 12 via the amplifiers 9 and 10. At this time, the time reference signal St is, as shown in FIG.
Are recorded simultaneously in time division. Also, this time reference signal
St uses a dispersed signal in order to avoid the effects of dropout and the like due to defects in the recording medium. It should be noted that the dispersed signal may be, for example, a Barker sequence or an M sequence.

Next, the reproducing system circuit B of the wideband signal recording / reproducing apparatus according to the present invention will be described with reference to FIG.

The information signals of a plurality of channels recorded as described above and the time-reference dispersed signal multiplexed with these signals are
The reproduction heads 13 and 14 extract the time reference signal St and the information signal Sw in a time-multiplexed form. These signals are supplied to post-signal processing circuits 17 and 18 via amplifiers 15 and 16, and the information signal Sw is demodulated into original information signals (for example, FM demodulation) in the signal processing circuits 17 and 18. Further, these signals are converted into digital signals by the A / D converters 19 and 20. This digital signal is used by the system clock generator 21.
According to the clock signal Sc from the memory M as a storage means
Written in 1, M2. The time reference signal St is an impulse P ₁ as shown in Figure 4 by a detector (detecting means) 22, 23 made of a correlator for detecting a temporal shift between the output signals of the reproducing heads 13 and 14 , P ₂ , and output to the CPU 24 as a control means for correcting the time lag between the output signals. At this time, if an alignment error occurs between the channel CH1 and the channel CH2, a time error Δt occurs as shown in FIG. The CPU 24 detects this temporal error Δt, and based on the impulses P ₁ and P ₂ , the memory M according to the error Δt.
The read timing of 1 and M2 is controlled to correct the time error Δt. As a result, the demultiplexer 25 forms an array of signals with no time error. After that, it is converted into an analog signal by the D / A converter 26 and output as a reproduction output.

In this way, since the time shift is corrected using the dispersed signal for the time reference, it is possible to avoid the influence of dropout or the like.

Although the wideband signal is divided into two channels in the above embodiment, it is needless to say that the present invention is not limited to two channels and can be applied to other channels.

〔effect〕

As described above, according to the present invention, there is an effect that the stability of image quality can be improved and a system cost can be reduced, and an effect can be avoided by a dropout or the like.

[Brief description of drawings]

FIG. 1 is a block diagram showing a recording system circuit of a wide band signal recording / reproducing apparatus according to the present invention, FIG. 2 is a diagram showing a signal recording state by the one shown in FIG. 1, and FIG. 3 is related to the present invention. FIG. 4 is a block diagram showing a reproducing system circuit of the wide band signal recording / reproducing apparatus, and FIG. 4 is a diagram showing a signal reproducing state by the one shown in FIG. 2 ... Multiplexer, 13,14 ... Playback head, 22,23 ...
… Detector (detection means), 24… CPU (control means), St…
... Time reference signal, Sw ... Recording signal, CH1, CH2 ... Channel, A ... Recording circuit, B ... Playback circuit, M1, M2 ...
... Memory (storage means).

Claims (1)

[Claims] 1. A plurality of reproducing heads for respectively reproducing a plurality of channels of signals and a time-reference dispersed signal multiplexed with these signals, a storage means for storing an output signal of each reproducing head, and the dispersed signal. And a detection means for detecting a time lag between the output signals and a read control of the storage means based on the detection output of the detection means to correct the time lag between the output signals. And a control unit for controlling the reproduction apparatus.