JP2827600B2 - Method for detecting control signal head mounting position of rotary head type magnetic recording / reproducing apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting a control signal head mounting position of a rotary head type magnetic recording / reproducing apparatus used for adjusting the height of a control signal head for recording / reproducing a control signal on / from a magnetic tape. .

[0002]

2. Description of the Related Art Conventionally, in a rotating head type magnetic recording / reproducing apparatus of a helical scan type such as a VHS type,
In order to control the relative positional relationship between the rotating magnetic head and the recording track during reproduction, a signal synchronized with the rotation phase of the rotating magnetic head during recording is recorded as a control signal in the longitudinal direction of the tape. The recording / reproduction of the control signal is performed by a control signal head, and the height adjustment of the control signal head affects quality such as compatibility of the apparatus. Hereinafter, an example of a method of adjusting the height of the control signal head of the rotary head type magnetic recording / reproducing apparatus will be described with reference to FIGS.

In FIG. 3, reference numeral 1 denotes a reference magnetic tape, and a side edge of the recording track is located at a position L2 near one side edge E1 located below the reference magnetic tape from a specified position L1 defined in advance by a standard. Is located on the first recording track 2
A first pulse signal 3 of a constant level synchronized with the rotation phase of the rotating magnetic head during recording is recorded as a control signal. The first recording track 2 is provided close to and parallel to a side edge located at the position L2, that is, the side edge and the predetermined position L
A standard signal having a constant frequency and a constant level is recorded as a second signal on a second recording track 4 provided between the first recording medium 1 and a position L3 farther from the one side edge E1. In selecting the frequency of this standard signal, when the reproduced standard signal waveform is displayed on the oscilloscope display, it is necessary to obtain a level that facilitates visual judgment and use a standard signal with the highest possible frequency. Therefore, about 2 KHz is selected in consideration of the fact that the visual determination of the waveform becomes easy. The reference magnetic tape 1 is loaded into a rotary head type magnetic recording / reproducing apparatus to be measured and reproduced, so that a control signal head of the rotary head type magnetic recording / reproducing apparatus outputs a first pulse signal and a standard signal which are control signals. And outputs a reproduced signal having the second signal. The first pulse signal controls the relative positional relationship between the rotating magnetic head and the reference magnetic tape 1 in the tape longitudinal direction, and is obtained directly from the reproduction signal, or
A second signal obtained by separating the reproduced signal by a filter.
While detecting the relative height position between the control signal head and the reference magnetic tape 1 based on the signal level of
The relative height position of the control signal head, that is, the mounting position is adjusted so that the detected level becomes a predetermined level.

[0004]

However, in the above configuration, the output level of the second signal indicating the relative height position between the control signal head and the reference magnetic tape is determined as shown in FIG. The peak difference of the output waveform displayed on the oscilloscope display is measured and determined, but the peak difference is small and the waveform displayed in a noise waveform shape is difficult to measure. The signal head mounting adjustment accuracy was not sufficiently obtained.

As a countermeasure, an attempt was made to increase the level of the standard signal during recording so as to increase the peak difference of the waveform of the second signal during reproduction. However, a sufficient peak difference could not be obtained. .

The present invention solves such a problem, and easily,
It is another object of the present invention to provide a method for detecting a control signal head mounting position of a rotary head type magnetic recording / reproducing apparatus, which can surely improve the accuracy of the control signal head mounting adjustment.

[0007]

A method for detecting a control signal head mounting position of a rotary head type magnetic recording / reproducing apparatus according to the present invention comprises the steps of: recording a recording track at a position closer to one side edge of a magnetic tape than a predetermined position; A first pulse signal of a constant level synchronized with the rotation phase of the rotating magnetic head at the time of recording is recorded as a control signal on the first recording track where the side edge of the first recording track is located. A rotary head type magnetic recording / reproducing apparatus to measure a reference magnetic tape on which a second pulse signal having a constant level opposite in polarity to the first pulse signal is recorded on a second recording track close to and parallel to a side edge. And outputs a reproduction signal having a first pulse signal and a second pulse signal from a control signal head of the rotary head type magnetic recording / reproducing apparatus. A signal controls the relative positional relationship between the rotating magnetic head and the magnetic tape in the longitudinal direction of the tape, and detects the relative height position between the control signal head and the reference tape based on the level of the reproduced second pulse signal. Is what you do.

[0008]

According to the method of detecting the control signal head mounting position of the rotary head type magnetic recording / reproducing apparatus of the present invention, the first pulse signal recorded on the reference magnetic tape and the first pulse signal having a constant level opposite in polarity to the first pulse signal are recorded. The second pulse signal is reproduced by the control signal head of the rotary head type magnetic recording / reproducing apparatus to be measured, and the first signal controls the relative positional relationship between the rotary magnetic head and the reference magnetic tape in the tape longitudinal direction. In addition, since the relative height position between the control signal head and the reference magnetic tape is detected based on the level of the reproduced second pulse signal, the waveform of the second pulse signal is displayed on a display of an oscilloscope. When the level is visually determined from the waveform, the level of the displayed second pulse signal can be increased, and Because it is displayed as a waveform, readily said visual estimation judgment, and becomes reliably, it is possible to obtain the accuracy of the mounting adjustment of the control signal head.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for detecting a control signal head mounting position of a rotary head type magnetic recording / reproducing apparatus according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view of a reference magnetic tape showing recording states of a first pulse signal and a second pulse signal, and FIG. 2 is a waveform of an output level of a second pulse signal obtained by reproducing the reference magnetic tape. FIG.

In FIG. 1, reference numeral 1a designates a reference magnetic tape used for adjusting the mounting of a control signal head of a rotary head type magnetic recording / reproducing apparatus in the VHS system, and a prescribed position L of the reference magnetic tape 1a defined in advance.
1, one side edge of the recording track is located at a position L2 closer to one side edge E1 located below the reference magnetic tape 1a, and the other side of the recording track is located at the one side edge E1. A first recording track 2 where the side edge is located is formed.

The first recording track 2 has a first level of a fixed level synchronized with the rotation phase of the rotating magnetic head during recording.
Is recorded as a control signal.

The recorded first pulse signal 3 is composed of a pair of a positive pulse signal 3a and a negative pulse signal 3b. In the reproducing mode in the VHS type magnetic recording / reproducing apparatus, the positive pulse signal is used. 3a is used as a control signal. Therefore, also in this embodiment, the first pulse signal 3 will be described below as a positive pulse signal 3a.

The first recording track 2 is provided so as to be close to and parallel to the side edge located at the position L2, that is, a predetermined distance farther from the position L2 and the one side edge E1 than a predetermined specified position L1. A second recording track 4 provided as a recording track between the first and second limit positions L3 has a polarity opposite to that of the positive pulse first pulse signal 3, that is, a negative second pulse signal.
Is recorded at a constant level.

An embodiment of a method for producing the above-described reference magnetic tape 1a will be described.

First, a second pulse signal 6 is recorded by a first control signal head from the limit position L3 of the reference magnetic tape 1a to one side edge E1 as a recording track, and thereafter, the first recording is performed. The first pulse signal 3 is overwritten on the track 2 by the second control signal head as a control signal. As a result, it is possible to create the reference magnetic tape 1a in which the first pulse signal 3 is recorded on the first recording track and the second pulse signal 6 is recorded on the second recording track.

The reference magnetic tape 1a is loaded into a rotary head type magnetic recording / reproducing apparatus to be measured and reproduced, whereby a first pulse signal 3 and a second pulse signal 3 are output from a control signal head of the rotary head type magnetic recording / reproducing apparatus. A reproduced signal composed of the pulse signal 6 of the above is output. The first pulse signal 3 controls the relative positional relationship between the rotating magnetic head and the magnetic tape in the longitudinal direction of the tape, and the waveform 6a of the reproduced second pulse signal 6 displayed on the display of the oscilloscope ( 2), the relative height position of the control signal head and the reference magnetic tape, that is, the mounting position is adjusted so that the output detected and determined to be the predetermined level V1.

The relative height position of the control signal head capable of obtaining the predetermined level V1 is referred to as the position L2 in order to obtain compatibility as a magnetic recording / reproducing apparatus.
Position L1 set between the position and the predetermined limit position L3
The output obtained when the one edge of the control signal head is positioned at the specified position L1 and the second pulse signal 6 recorded from the position L2 to the predetermined specified position L1 is reproduced. Becomes a predetermined level V1.

[0018]

As described above, the method of detecting the control signal head mounting position of the rotary head type magnetic recording / reproducing apparatus according to the present invention uses the first pulse signal and the first pulse signal recorded on the reference magnetic tape. A second pulse signal of a fixed level of opposite polarity is reproduced by a control signal head of a rotary head type magnetic recording / reproducing apparatus to be measured, and the rotary magnetic head and the magnetic tape are separated by the first pulse signal in the reproduced signal. Controls the relative positional relationship of the tape in the longitudinal direction,
Since the relative height position between the control signal head and the reference magnetic tape is detected based on the level of the second pulse signal in the reproduced signal, the waveform of the second pulse signal is displayed on a display of an oscilloscope. When the level is visually determined from the output waveform, the level of the displayed second pulse signal can be increased, and the displayed second pulse signal is displayed as a pulse-like waveform. This makes it possible to improve the accuracy of the mounting adjustment of the control signal head.

Further, the second pulse signal has a second polarity with respect to the polarity of the first pulse signal.
Are set to have opposite polarities, the second pulse in the reproduction signal is used as a first pulse signal for controlling the relative positional relationship between the rotating magnetic head and the magnetic tape in the tape longitudinal direction. A pulse signal is not detected, and the control does not become abnormal as an apparatus.

[Brief description of the drawings]

FIG. 1 is a plan view showing an example of a reference magnetic tape used in a method for detecting a control signal head attachment position of a rotary head type magnetic recording / reproducing apparatus according to the present invention.

FIG. 2 is a waveform diagram of a second pulse signal reproduced from the reference magnetic tape.

FIG. 3 is a plan view showing an example of a method for adjusting the height of a control signal head mounting position of a conventional rotary head type magnetic recording / reproducing apparatus.

FIG. 4 is a waveform diagram of a second pulse signal in a conventional example.

[Explanation of symbols]

 1a Reference magnetic tape 2 First recording track 3 First pulse signal 3a Pulse signal 4 Second recording track 6 Second pulse signal 6a Waveform

Claims (1)

(57) [Claims] 1. A synchronous phase with a rotation phase of a rotary magnetic head at the time of recording on a first recording track in which a side edge of a recording track is located closer to one side edge of a magnetic tape than a predetermined specified position. A first pulse signal having a constant level is recorded as a control signal, and a second recording track adjacent to and parallel to the side edge of the first recording track has a constant level having a polarity opposite to that of the first pulse signal. The reference magnetic tape on which the second pulse signal has been recorded is loaded into a rotary head type magnetic recording / reproducing apparatus to be measured, and the control signal head of the rotary head type magnetic recording / reproducing apparatus receives
And a reproduction signal having a second pulse signal and a second pulse signal. The first pulse signal controls the relative positional relationship between the rotating magnetic head and the magnetic tape in the longitudinal direction of the tape. A method of detecting a control signal head mounting position of a rotary head type magnetic recording / reproducing apparatus, wherein a relative height position between the control signal head and a reference tape is detected based on a level of a pulse signal.