JPH0562301A - Magnetic recording / reproducing device - Google Patents

Abstract

(57) [Abstract] [Purpose] In a magnetic recording / reproducing apparatus that records a PCM digital audio signal and an FM-modulated audio signal, and superimposes and records an FM-modulated video signal, improves the accuracy of automatic tracking adjustment and optimally traces. It can be so. [Arrangement] An error pulse detection circuit 25 for detecting and monitoring an error pulse of a PCM digital audio signal from the PCM audio signal processing circuit 19 is provided so that the tracking processing microcomputer 15 outputs the output signal of the video signal embedding detection circuit 20. In addition to the input, the error pulse information is input to perform automatic tracking adjustment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus, and more particularly to a VT for recording / reproducing video signals and PCM audio signals.
The present invention relates to a magnetic recording / reproducing apparatus that is used in R etc. and that performs an optimized automatic tracking operation.

[0002]

2. Description of the Related Art Conventionally, a magnetic recording / reproducing apparatus of this type monitors output signals of a video head and an audio head in order to automatically control the magnetic head to optimally trace a track on a magnetic tape during reproduction. However, the overall judgment is made so that the respective output signals are maximized.

A block diagram of such a conventional magnetic recording / reproducing apparatus having an automatic tracking adjustment function is shown in FIG. In FIG. 2, the conventional magnetic recording / reproducing apparatus includes a video head 11 for reading a video signal from a video track of a magnetic tape 22, a video head AMP 12 for amplifying an output signal from the video head 11, and a video head AM.
A video signal processing circuit 13 for processing the output signal of P12;
An envelope detection circuit 14 that obtains a voltage proportional to the head output of a video signal, a tracking processing microcomputer 15 that performs automatic tracking adjustment, an audio head 16 that reads an audio signal from an audio track of a magnetic tape 22, and an output from the audio head 16. Audio head AMP17 for amplifying signals and audio head A
An FM audio signal processing circuit 18 that FM demodulates an FM-modulated audio signal of the output signal from the MP17, and a PCM that demodulates the PCM-processed audio signal of the output signal from the audio head AMP17 into a digital audio signal. An audio signal processing circuit 19 and an envelope detection circuit 20 for obtaining a voltage proportional to the head output of the audio signal,
Motor control circuit 2 for positioning the magnetic head 24 under the control of the tracking processing microcomputer 15
1 and 1.

Next, the operation of the conventional magnetic recording / reproducing apparatus configured as described above will be described. First, the video signal read from the video head 11 is
The signal is amplified by MP12 and output to the video signal processing circuit 13. In the video signal processing circuit 13, the video head AMP12
The video signal amplified by is demodulated and output to the outside as a reproduced video signal. Where the video head AM
The output signal of P12 is also output to the envelope detection circuit 14,
A voltage proportional to the head output is obtained in the envelope detection circuit 14, and the output signal is input to the tracking processing microcomputer 15 for automatic tracking adjustment.

Similarly, the audio signal is read by the audio head 16, and the output signal from the audio head 16 is amplified by the audio head AMP 17. The audio signal output from the audio head AMP 17 is FM demodulated by the FM audio signal processing circuit 18, and P
The CM signal portion is demodulated by the PCM audio signal processing circuit 19 and output to the outside as an audio signal.
Here, the output signal of the audio head AMP 17 is also input to the envelope detection circuit 20, and a voltage proportional to the head output is input to the tracking processing microcomputer 15 via the envelope detection circuit 20. Tracking processing microcomputer 15
Then, the output signals of the video signal detection circuit 14 and the audio signal detection circuit 20 input from the envelope detection circuit 14 are monitored to determine the optimum head trace position.

This tracking adjustment is performed by, for example, a VTR.
Regarding the recording state in the long time mode, since the track width of the magnetic tape to be recorded is generally smaller than the head width of the magnetic head for recording and reproducing, the head output changes when the tracking is changed and the trace position is changed. To do. This is illustrated by the schematic diagram shown in FIG. 3, which shows the trace position of the magnetic track and the output voltage of the magnetic head when the magnetic head 24 traces the magnetic track 23 on the magnetic tape 22. It is a figure which shows the relationship of.

[0007]

As described above, in the tracking adjustment of the conventional magnetic recording / reproducing apparatus, since the output voltage signal of the magnetic head becomes a trapezoidal wave due to the tracking change, the track position where the tracking adjustment is optimum. There was a problem that it was difficult to understand. That is, although the azimuth is different from that of the adjacent track, the center of the magnetic track is not always the optimum tracking position because it is subject to crosstalk interference, and the envelope detection circuit is not limited by the contents of the recorded video signal or FM audio signal. Since the output signal of 1 changes at the same tracking position, it is difficult to find the optimum point.

The present invention has been made in order to solve the above-mentioned problems, and the automatic tracking adjustment is performed so that the optimum tracking position can be obtained by monitoring the error pulse information of the PCM audio signal. The purpose is to obtain a magnetic recording / reproducing apparatus.

[0009]

In order to achieve the above object, a magnetic recording / reproducing apparatus according to the present invention is based on a detecting means for detecting an error pulse of a PCM digital audio signal, and information based on this detecting means. A magnetic tape control unit for controlling the magnetic tape.

[0010]

Therefore, according to the magnetic recording / reproducing apparatus of the present invention,
At the time of reproduction, the information corresponding to the error pulse of the PCM digital audio signal is monitored together with the output signal of the video detection circuit of the video signal, and the automatic tracking adjustment for optimally tracing the track of the magnetic tape by the magnetic head is performed.
The tracking position can be controlled so that the error pulse of the PCM audio signal is minimized, and the optimum tracking position can be accurately determined.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a magnetic recording / reproducing apparatus according to this embodiment.

In FIG. 1, the same or corresponding parts as those of the conventional magnetic recording / reproducing apparatus are designated by the same reference numerals to simplify the description. That is, the magnetic recording / reproducing apparatus of the present invention includes a video head 11, a video head AMP 12, a video signal processing circuit 13, an envelope detection circuit 14, a tracking processing microcomputer 15, an audio head 16, an audio head AMP 17, and FM audio signal processing circuit 18
, PCM audio signal processing circuit 19, and envelope detection circuit 2
0, the motor control circuit 21, and the error pulse detection circuit 2 for detecting and monitoring the error pulse of the PCM digital audio signal output from the PCM audio signal processing circuit 19.
It is composed of 5 and.

Next, the operation will be described. In the operation of the magnetic recording / reproducing apparatus of the present invention, the description of the same parts as those of the related art will be omitted.

In the magnetic recording / reproducing apparatus of the present invention configured as described above, the audio signal read from the audio head 16 is processed by the FM audio signal processing circuit 18 and the PCM audio signal processing circuit 19 as in the conventional case. But
Further, the error pulse detection circuit 25 detects an error pulse of the PCM digital audio signal, and the detected error pulse information is input to the tracking processing microcomputer 15.

In the tracking processing microcomputer 15, in addition to the output signal of the video signal embedding detection circuit 14 and the output signal of the audio signal embedding detection circuit 20, the error pulse information input from the error pulse detection circuit 25 is used to make an accurate optimum. The tracking position can be obtained.

That is, the error pulse information detected by the error pulse detection circuit 25 is digitally processed data and can be known as a concretely determined amount.
Depending on the contents of the signal data, the f
The output signal does not change under the influence of the characteristics. Therefore, it becomes possible to know the optimum tracking position more accurately.

Further, since the video head and the audio head have different attachment positions, when reproducing a magnetic tape recorded by another VTR device, depending on the attachment positions of the video track and audio track of the VTR, the output signals of the respective output signals are different. The optimal tracking position may be different. In such a case, conventionally, a method that takes advantage of the characteristics of each VTR has been adopted, such as an intermediate value between the optimum points of both video tracks and audio tracks, or a position where the video signal is emphasized.

In the magnetic recording / reproducing apparatus of the present embodiment, the optimum tracking position of the audio track can be made more accurate by adding error pulse information as input information in the tracking processing microcomputer 15. Moreover, the weighting of the relative positional relationship with the optimum tracking position of the video signal can be freely selected as in the conventional case.

If the automatic tracking adjustment is performed only by the error pulse information, it is not always easy to determine the optimum tracking position as the VTR, and the entire device may not reach the optimum point. It is expected that. However, in the magnetic recording / reproducing apparatus of the present embodiment, since the output signal of the envelope detection circuit 14 of the video signal at this point is also monitored, such a problem can be avoided.

Further, in self-recording / reproducing in which recording / reproducing is performed by the own device, the optimum points of the video track and the audio track are matched because the respective mounting positions are not different. Therefore, in the magnetic recording / reproducing apparatus of the present embodiment, since the tracking information is enhanced by adding the error pulse information, there is a problem that the optimum point due to the crosstalk interference becomes unfavorable in the conventional method. The tracking point can also be accurately obtained.

[0021]

As described above, according to the magnetic recording / reproducing apparatus of the present invention, the output signal of the video signal detection circuit and the information corresponding to the error pulse of the PCM digital audio signal are monitored. Therefore, the optimum tracking point of the audio head can be determined more accurately, the accuracy of automatic tracking adjustment is improved, and there is an effect that optimum tracing can be performed.

[Brief description of drawings]

FIG. 1 is a block diagram of a magnetic recording / reproducing apparatus showing an embodiment of the present invention.

FIG. 2 is a block diagram of a conventional magnetic recording / reproducing apparatus.

FIG. 3 is a schematic diagram showing a relationship between a magnetic tape, a magnetic track and a magnetic head (FIG. 3A), and a graph showing a relationship between a trace position of the magnetic track and an output voltage of the magnetic head (FIG. 3B).

[Explanation of symbols]

 11 video head 12 video head AMP 13 video signal processing circuit 14 video signal embedding detection circuit 15 tracking processing microcomputer 16 audio head 17 audio head AMP 18 FM audio signal processing circuit 19 PCM audio signal processing circuit 20 audio signal embedding detection circuit 21 motor control Circuit 22 Magnetic tape 23 Magnetic track 24 Magnetic head 25 Error pulse detection circuit

Claims (1)

[Claims] 1. A PCM-converted digital audio signal and FM.
A helical scan type magnetic recording / reproducing apparatus in which a modulated audio signal is recorded on a magnetic tape by a pair of magnetic heads, and an FM-modulated video signal is superimposed and recorded by the other pair of magnetic heads. A magnetic head is equipped with an automatic adjustment means for monitoring information corresponding to an error pulse of a PCM digital audio signal read and reproduced from the magnetic head, and for performing automatic tracking adjustment for optimally tracing the track of the magnetic tape. And a magnetic recording / reproducing apparatus.