JPH06282826A - Method of measuring deviation of azimuth angle - Google Patents

Abstract

PURPOSE:To achieve an accurate and handy measurement of a deviation of an azimuth angle of a magnetic head. CONSTITUTION:A sweeping signal with the frequency thereof varying from 0Hz to several MHz is recorded on one track with a known track width W thereof using a magnetic head with an azimuth angle thereof known as differing from the azimuth angle of a magnetic head 15 to be measured to prepare a reference tape for measurement. Then, the reference tape is set on a magnetic reproducer carrying the magnetic head 15 to be measured to reproduce. A reproduction signal of the sweeping signal is outputted from the magnetic head 15 to be measured. But, when a deviation of the azimuth angle and the frequency of the sweeping signal in the recording and reproduction meet a specified relationship, an azimuth loss increases. The deviation of the azimuth angle of the magnetic head to be measured can be measured from a suppressing point of the reproduction signal. At this point, as reproduction is performed during the stoppage of the tape, the effect of disturbance caused by the running of the tape is reduced thereby achieving accurate measurement.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a helical scan type magnetic recording or reproducing apparatus which records or reproduces a video signal or an audio signal on a magnetic tape by a magnetic head rotating together with a rotary drum. The present invention relates to improvement of an azimuth angle deviation measuring method for measuring an azimuth angle deviation.

[0002]

2. Description of the Related Art In recent VTRs having a narrow track width, guard bandless azimuth recording is predominant not only for consumer use but also for professional use. For example, in the VHS (registered trademark) system, ch (channel) 1 and ch 2 The azimuth angle of the magnetic head has an angle of ± 6 degrees with respect to the direction perpendicular to the running direction.

By the way, recently, improvements have been made in order to improve the image quality and the functionality of VTRs for general households such as the VHS system. For example, with respect to high image quality, VTRs of S-VHS (registered trademark) specifications for achieving higher bandwidth have become widespread, and the maximum frequency of recording signals has also exceeded 7 MHz. On the other hand, with regard to higher functionality, devices have been provided that realize trick play during reproduction, and improvements have been made in recording track locus tracking technology used for VTR noiseless slow or noiseless still reproduction.

Regarding the former image quality improvement, since the recording signal wavelength becomes shorter as the signal bandwidth becomes higher, the control of the azimuth angle accuracy of the magnetic head used for recording and reproduction is becoming stricter. With regard to the latter function enhancement, since the magnetic head chip is fixed to the special reproduction actuator and this actuator is fixed on the rotating drum, the magnetic head chip is kept within a predetermined range. The managed azimuth angle may deviate during the manufacturing process.

In the S-VHS type VTR, the allowable range of azimuth angle deviation of the magnetic head is approximately ± 10 '(10 minutes).
However, the actual condition is that the magnetic head assembly is managed within the range of a deviation of 4-5 'or less.

As a conventional method for measuring such an azimuth angle shift, there is an optical method using a microscope or the like. According to this, at the stage where the magnetic head is mounted on the rotary drum, the gap portion of the magnetic head is enlarged by a microscope, the optical image thereof is subjected to image processing, and the azimuth angle deviation is measured.

[0007]

However, in the above-mentioned conventional techniques, it is necessary to set a jig such as a microscope on the object to be measured, which requires time and effort for the measurement. Therefore, conventionally, the sampling check of the azimuth angle is performed at a rate of, for example, about one product per one lot.

However, as described above, recently, high accuracy has been required for the azimuth angle from the viewpoints of high image quality and high functionality, and in some cases, not only the sampling check but also the 100% check may be required. There is a nature. The present invention focuses on these points, and an object thereof is to provide an azimuth angle deviation measuring method capable of accurately and easily measuring the azimuth angle deviation of a magnetic head.

[0009]

In order to achieve the above object, the present invention is a magnetic head having a known azimuth angle different from the azimuth angle of the magnetic head to be measured, and a predetermined one track length includes at least one sweep. A standard tape for measurement created by recording a sweep signal in the frequency range with a known track width is set in a magnetic reproducing device equipped with the magnetic head to be measured, reproduced while the tape is stopped, and output from the magnetic head to be measured. It is characterized in that the azimuth angle deviation of the magnetic head to be measured is measured from the suppressed state of the reproduced signal.

[0010]

According to the present invention, a magnetic recording apparatus equipped with a magnetic head having a known track width and a known azimuth angle records a sweep signal in a predetermined frequency range at a tape standard speed to prepare a standard tape for measurement. . And this standard tape for measurement
A magnetic reproducing apparatus equipped with a magnetic head to be measured is set and reproduced, and a frequency of a suppressed portion is read from an envelope waveform of a sweep signal obtained thereby to measure an azimuth angle deviation of the magnetic head to be measured. Since the standard tape for measurement is reproduced in a stopped state, a measurement error due to disturbance caused by driving the tape does not occur.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the azimuth angle deviation measuring method according to the present invention will be described in detail below with reference to the accompanying drawings. <Basic Method> First, the basic method of this embodiment will be described. As is well known, if the azimuth angle of the magnetic head gap is different between the recording side and the reproducing side,
This causes so-called azimuth loss, which causes signal deterioration. When this is expressed by a mathematical expression, it becomes as shown in the following (Equation 1).

[0012]

[Equation 1]

In this equation (1), when the numerator becomes zero, the azimuth loss L becomes infinite. When this condition is obtained, the following equation (2) is obtained. Sin [πW ₀ / λ {Tan (θ)}] = 0 πW ₀ / λ {Tan (θ)} = π, 2π, ..., nπ (Equation 2) where n is an integer. Here, if n = 1, then λ = W ₀ {Tan (θ)} …………………… (Equation 3).

FIG. 1 shows the conditions of the equation (3). In FIG. 1A, a signal having a width W and a predetermined frequency is recorded on the track 10 on the magnetic tape. The arrow FA indicates the traveling direction of the reproducing magnetic head 14. It is assumed that the azimuth angle of the recording head (not shown) of the recorded track 10 is as shown by the dotted line in the figure, and this is reproduced by the reproducing magnetic head 14 having the gap 12. In such a case, the deviation of the azimuth angle between recording and reproducing is as shown by θ in the figure.

Here, considering the case of satisfying the relationship of the equation (3), from the recorded track 10 corresponding to just one wavelength (λ) from the upper part to the lower part of the gap 12 of the reproducing magnetic head 14. This corresponds to the case where the magnetic flux is obtained (see FIG. 7B). In this case, the reproducing magnetic head 14
In the end, the output of is canceled out in the entire gap 12 and becomes close to zero.

In the case of FIG. 3B, even if a positive signal is obtained on the left side of the gap 12, a substantially equal negative signal is obtained on the right side, so that it is canceled as a whole. . In the case of the example of FIG. 1, the equation (3) is not related to the track width WA of the reproducing magnetic head 14, and the track width W of the recorded track 10 is
Corresponds to the overlapping width W ₀ of the head and the track. That is, the expression (3) depends only on W.

FIG. 2 is a graph showing the relationship of the equation (1). As shown in FIG. 3, this graph shows that the track width W is 27 μm, the relative linear velocity between the recording magnetic head and the magnetic tape is 5.8 m / s, and the sweep signal whose frequency changes from 0 Hz to several MHz is applied to the magnetic tape. Prepare the recorded one, and the azimuth angle deviation θ is 3
Reproducing magnetic head 1 with a gap of 1 degree, 2 degrees, 1 degree and 20 '
5 corresponds to the output signal obtained by reproduction. The vertical axis of FIG. 2 is the azimuth loss (dB), and shows that the loss increases as it goes down. The horizontal axis is the signal frequency (MH
z). A graph in which the azimuth angle deviation θ in the figure is 3 ° is shown in FIG.

As shown in FIGS. 2 and 3, when the frequency satisfies the condition of the equation (3), the azimuth loss increases. For example, in the case of an azimuth angle deviation of θ = 3 °, the first dip (n = 1) appears near 4 MHz, and the second dip (n = 1) near 8 MHz.
= 2) is displayed. In the case of an azimuth angle deviation of θ = 2 °, the first dip (n = 1) appears near 6 MHz. The present invention utilizes such a relationship to measure the azimuth angle deviation.

By the way, referring to these graphs,
It can be seen that as the azimuth angle deviation θ becomes shallower, the frequency at which the dip in which the azimuth loss increases increases appears, and it becomes difficult to measure the dip frequency. For example,
At θ = 20 ′, it is considered that the dip cannot be measured unless it has a very high frequency of several tens of MHz. On the contrary, if the azimuth angle deviation θ is increased, the frequency of the dip is lowered and the measurement becomes easier. However, if θ becomes too large, the resolution will decrease and the measurement error will increase.

From this point of view, the azimuth angle deviation θ between the recorded magnetic tape of the sweep signal and the magnetic head to be measured (reproducing head) is θ in the case of a magnetic head having a track width W of 20 to 50 μm. It will be convenient for the measurement if it is set to be about 3 °.

In the case of the VHS system, for example, ch1
4A, the azimuth angle is set to be +6 degrees in the counterclockwise direction with respect to the direction FB orthogonal to the head traveling direction FA, as shown in FIG. Therefore, this +
In order to obtain a recorded track locus having an angle deviation of about 3 ° with respect to an azimuth angle of 6 °, a sweep signal of a magnetic head having an azimuth angle of about 6 + 3 = 9 ° (or 6-3 = 3 °) is used. You just have to make a record.

Similarly, in the ch2 magnetic head, as shown in FIG. 2B, the head running direction FA is orthogonal to the direction FB.
On the other hand, the azimuth angle is set to be 6 ° in the clockwise direction, that is, −6 ° in the counterclockwise direction. Therefore, in order to obtain a recorded track locus having an angular deviation of about 3 ° with respect to the -6 ° azimuth angle, -6-3 =-
It suffices to record the sweep signal with a magnetic head having an azimuth angle of about 9 ° (or −6 + 3 = −3 °).

FIG. 5 is a graph showing the conditions of the equation (3). The horizontal axis represents the azimuth angle of the magnetic head to be measured, and the vertical axis represents the frequency at which a dip occurs when n = 1 ( It corresponds to the wavelength λ in the formula (3). The condition of the recorded tape is that the track width W is 45.5.
μm, and the azimuth angle of the recording magnetic head is 9.27 °. Such a recorded tape is reproduced by the magnetic head to be measured to obtain a reproduction sweep signal, and the n = 1 dip frequency at which the signal level becomes zero is detected from the envelope waveform. Then, the measurement can be performed by reading the azimuth angle of the magnetic head to be measured from the graph of FIG.

The procedure for measuring the azimuth angle deviation of the magnetic head to be measured according to this embodiment is summarized as follows. Using a magnetic head set to a known azimuth angle that is deviated by about 3 ° from the azimuth angle of the magnetic head to be measured, a sweep signal whose frequency changes from zero to several MHz is used with a known track width W. Record on magnetic tape and make a standard tape for measurement.

Next, this standard tape is set on a VTR equipped with a magnetic head having an azimuth angle to be measured and reproduced, and a reproduced signal is measured. Next, the frequency of the reproduced signal is analyzed to detect the dip frequency, and the azimuth angle deviation θ is obtained from the value and the value of the known track width W using the equation (3). Then, the value of the azimuth angle of the measured magnetic head is obtained from this θ and the known value of the azimuth angle of the recording magnetic head.

<Method for Creating Standard Tape> Next, a method for creating a standard tape for measurement will be described. FIG. 6 shows the structure of a VTR for making a standard tape. In the figure, the output side of the composite video signal output unit 20 which is a normal video signal is connected to the signal processing circuit 22, and the output side of this signal processing circuit 22 is connected to the switching input side a of the changeover switch 24. Has been done. A sweep oscillator 26 is connected to the other input side b of the changeover switch 24.

A sync separation circuit 28 is connected to the composite video signal output section 20, and the output side of this sync separation circuit 28 is connected to the switching input side a of another changeover switch 30. In addition, the sweep oscillator 26 includes a synchronization signal generator 3
2 is connected, and the output side of the synchronizing signal generator 32 is connected to the other changeover input side b of the changeover switch 30.

Next, the output side of the changeover switch 24 is for recording / recording.
The output side of the recording / reproducing amplifier 34 is connected to the reproducing amplifier 34, and the magnetic heads H1 and H2 of the ch1 and ch2 of the rotating drum 36 are connected via a rotary transformer (not shown).
2 are connected to each. On the other hand, the changeover switch 30
Are connected to the drum phase control circuit 38 and the capstan phase control circuit 40, respectively, and these output sides are connected to motor drive amplifiers (indicated by MDA) 42, 4 respectively.
4 are connected respectively.

The output side of the MDA 42 is connected to the drum motor 46, and the output side of the MDA 44 is connected to the capstan motor 48. Further, the FG (speed) signal and PG (phase) signal output sides of the drum motor 46 are fed back to the drum phase control circuit 38.
The FG signal output side of the capstan motor 48 is fed back to the capstan phase control circuit 40.

Of the above units, the composite video signal output unit 2
0 outputs a composite video signal, and is compatible with various sources such as a television tuner and a video disc.
The signal processing circuit 22 is for performing signal processing necessary for recording the input composite video signal. The sweep oscillator 26 outputs a sync signal C.C. which corresponds to the vertical sync of the composite video signal. Based on SYNC, eg from zero to 6
A continuous sweep signal of about MHz is generated. In the synchronizing signal generator 32, the synchronizing signal C. SYNC is a genlock signal, which causes the vertical sync signal V.V. SYNC is output.

The recording / reproducing amplifier 34 is for amplifying the input RF signal and supplying it to the magnetic heads H1 and H2. The drum phase control circuit 38 is for performing servo control of the drum motor 46 using the synchronization signal supplied from the changeover switch 30 side and the FG and PG signals supplied from the drum motor 46 side. The capstan phase control circuit 40 receives the synchronization signal supplied from the changeover switch 30 side and the F signal supplied from the capstan motor 48 side.
The G signal is used to perform servo control of the capstan motor 48.

Next, the standard VHS magnetic head has the azimuth angle of ± 6 degrees as described above and the recording signal track width W.
Is, for example, 52 μm. However, each of the magnetic heads H1 and H2 of this apparatus has an azimuth angle of about ± 9 ° with respect to the direction orthogonal to the head traveling direction, and the recording signal track width W is set to about 45 μm. The azimuth angle and the recording signal track width are known in advance by the optical method. Further, the arrangement angle with respect to the rotary drum 36 is 180 degrees, and the protrusion amount is adjusted in the same manner as a standard magnetic head.

Next, the operation of the standard tape recording apparatus as described above will be described. First, the changeover switches 24, 3
It is assumed that 0 is switched to the a side. The operation in this case is
It is similar to a general VTR. That is, the composite video signal output from the composite video signal output section 20 is subjected to predetermined processing in the signal processing circuit 22, and then supplied to the recording / reproducing amplifier 34 via the changeover switch 24. Then, after amplification by this, it is supplied to the magnetic heads H1 and H2 via a rotary transformer.

On the other hand, the vertical sync signal separated by the sync separation circuit 18 is supplied to the drum phase control circuit 38 and the capstan phase control circuit 40 via the changeover switch 30, respectively. The drum phase control circuit 38 uses the input synchronization signal as a reference signal and controls the rotation of the drum motor 46 while referring to the FG and PG signals from the drum motor 46. As a result, the rotary drum 36, that is, the magnetic heads H1 and H2 are rotated in synchronization with the composite video signal.

In the capstan phase control circuit 40, the input synchronizing signal is used as a reference signal, and
The rotation control of the capstan motor 48 is performed with reference to the FG signal from the capstan motor 48. This allows the magnetic tape 50 to be transported at a standard running speed.

Next, when the standard tape according to this embodiment is produced, the changeover switches 24 and 30 are changed over to the b side. Then, instead of the composite video signal, the sweep oscillator 2
6, the sweep signal is output, and the sync signal generator 32 outputs the vertical sync signal of the sweep signal. That is, the sweep signal is recorded on the magnetic tape 50 instead of the composite video signal. The signal recording at this time is performed at the optimum recording voltage.

FIG. 7 shows a recorded track of a standard tape on which a sweep signal is recorded by the above-mentioned device. As shown in the figure, the sweep signal is recorded at the standard tape running speed, and the track width W is 45
Since it is set to be slightly narrower than μm, it has a slightly wide track locus with a guard band with alternating azimuth angles of ± 9 degrees.

In the figure, the track locus of the ch1 magnetic head H1 is T1, and the track locus of the ch2 magnetic head H2 is T2. The arrow FC indicates the running direction of the magnetic tape 50, and CP indicates a control pulse. The track width of the track loci T1 and T2 is W. Also, the sweep signal recorded on each track is synchronized with the vertical sync signal,
For example, the position of zero frequency of the sweep signal shown by the dotted line HP in the figure is located at substantially the same height through each track of the magnetic tape 50.

<Method of Measuring Azimuth Angle> Next, a method of measuring the azimuth angle of the magnetic head to be measured will be described using the standard tape 50 prepared as described above. First, the standard tape 50 is set in the VTR device in which the magnetic head to be measured 52 (see FIG. 7) is mounted. Then, the still reproduction, that is, the reproduction with the standard tape 50 stopped is performed. Here, when the width Wh1 of the measured magnetic head 52 is wider than the width W of the recorded tracks T1 and T2 (for example, the VHS type SP mode magnetic head is 52 μm), FIG. The measured magnetic head 52 repeatedly scans the shaded portion.

When the standard tape 50 is reproduced while running at the standard tape speed, the measured magnetic head 52
Will just scan the recorded track T1. However, in this example, since the standard tape 50 is stopped, the measured magnetic head 52 shifts by exactly one track and the measured magnetic head 52 moves to the recorded tracks T1, T2 of the standard tape 50.
Will be scanned.

The relationship between the recorded tracks T1 and T2 and the scanning locus of the magnetic head to be measured 52 in such a state will be further explained. As described above, in this example, the track width Wh1 of the magnetic head to be measured 52 is larger. It is wider than the width W of the recorded tracks T1, T2. Therefore, in FIG. 7A, the measured magnetic head 52 scans almost the entire width of the recorded track T1 in a relatively long portion near the center of the recorded track T1.

Therefore, the person who performs the measurement is
The stop position of the standard tape 50 with respect to the magnetic head 52 to be measured is controlled so that the dip frequency of the corresponding magnetic head 52 corresponds. This is because the overlapping width W ₀ is included in the above formula (Equation 3), and a measurement error occurs unless the measured magnetic head 52 covers the entire width W of the recorded track T1. This adjustment method will be described later.

FIG. 8 shows an example of the envelope signal of the reproduction signal output from the magnetic head to be measured 52. In this signal example, a portion of ΔV1 which is one vertical scanning period is a signal waveform at the time of stop reproduction of ch1 of the magnetic head to be measured 52, point P0 indicates the zero frequency f ₀ of the sweep signal, and point P1 indicates the first frequency. 1 shows the dip frequency (n = 1) f ₁ and the point P 2 shows the second dip frequency (n = 2) f ₂ . ΔV represents one vertical scanning period.

In the next vertical scanning period of ΔV2, c
Since the recorded track T1 recorded by the recording magnetic head of ch1 is being reproduced by the measured magnetic head of h2, the azimuth angle is greatly deviated. Therefore, almost no output signal is obtained.

Such a reproduced signal is supplied to a frequency spectrum analyzer (not shown) or the like for envelope detection to read the first dip frequency. In this case, if the measured magnetic head 52 does not cover the full width W of the recorded track T1 as described above, a measurement error will occur, so the tracking adjustment is performed so as to cover the full width W.

More specifically, according to the equation (3), the overlapping width W of the head and the track at the dip frequency is W.
_There is a proportional relationship between ₀ and the wavelength λ. Since the frequency corresponds to the reciprocal of the wavelength λ, the overlapping width W ₀ and the frequency have an inverse relationship. That is, the larger the overlapping width W _{0, the} lower the frequency. Therefore, when the standard tape 50 is slightly moved in the arrow FC or the opposite direction (see FIG. 7) and the overlapping width W ₀ is maximized, the graph in FIG. 8 is located at the leftmost position in FIG. The dip frequency is measured after such tracking adjustment is performed.

On the other hand, the relationship between the azimuth angle deviation θ and the dip frequency shown in FIG. 5 is obtained in advance for the standard tape 50. Then, the azimuth angle deviation θ is obtained from this relationship and the value of the dip frequency measured as described above. Further, the azimuth angle of the measured magnetic head 52 is obtained from the value of the azimuth angle deviation θ and the known value of the azimuth angle of the recording magnetic head.

Next, the width W of the recorded tracks T1, T2
When the width Wh2 of the measured magnetic head 52 is narrower than that (for example, the VHS type EP mode magnetic head is 26 or 19 μm), the shaded portion in FIG. 7B indicates the measured magnetic head 52. Will be repeatedly scanned. The scanning locus of the magnetic head to be measured 52 in the tape stopped state has the same inclination as in the SP mode. However, since the head width Wh2 is narrower than the track width W, scanning is performed over almost the entire track.
Therefore, the tracking adjustment described above is relatively simple. In this case, the overlapping width W _{0 of the} equation (3) is the gap width Wh2 of the magnetic head 52 to be measured, which is narrower than the track width W.

The track inclination angle when the magnetic tape is running is 5 ° 58′9.9 ″ in the case of VHS and 5 ° 56′7.4 ″ when the magnetic tape is stopped, which is the measured value of the azimuth angle. An angular deviation corresponding to the difference 2'2.5 "is apparently generated. Therefore, the difference 2'from the calculation result is obtained.
Be sure to correct 2.5 ″.

As described above, this embodiment has the following effects. (1) It is possible to easily measure the azimuth angle of the magnetic head to be measured without requiring a special jig such as a microscope unlike the conventional optical method. Therefore, at the time of assembling the VTR, it is possible to check all the deviations of the azimuth angles of the magnetic heads mounted on the rotary drum and mounted on the actuator.

(2) Since the standard tape for measurement is stopped and the measurement is performed, occurrence of a dip frequency detection error due to uneven feeding of the tape or disturbance to the tape running servo is prevented, resulting in high accuracy measurement. Is possible. In addition, measurement can be performed if there is only one track on which the sweep signal is recorded, and the time required for analysis by the spectrum analyzer can be secured sufficiently.

<Other Embodiments> The present invention is not limited to the above embodiments, and includes, for example, the following. (1) In the above-described embodiment, the sweep signal of 0 to several MHz is recorded once on one track of the standard tape, but it may be repeatedly recorded a plurality of times within one track. (2) In the above-described embodiment, the sweep standard recording tape is created by alternately recording the sweep signals for ch1 and ch2 of the magnetic head. However, separate measurement standard tapes may be created for ch1 and ch2. . In this case, the track loci do not become continuous as shown in FIG. 7, but the tracks are recorded every other track.

(3) The above embodiment is an example of measurement when so-called azimuth recording is performed, that is, when the magnetic head to be measured has a finite azimuth angle with respect to the direction perpendicular to its traveling direction. The present invention is also applicable to the case where the angle is 0 °, that is, when the gap of the magnetic head to be measured is formed in the direction perpendicular to the traveling direction (ideal state), such as when performing guard band recording. Applicable. This is the case when so-called guard band recording is performed.

(4) Specific numerical values such as the track width, tape speed, and azimuth angle shown in the above embodiment are examples, and the present invention is not limited to these. (5) In the above embodiments, the case of the VHS system was mainly described as an example, but the present invention is applicable regardless of whether it is VTR or DAT of another system, or commercial or home use.

[0055]

As described above, according to the azimuth angle deviation measuring method of the present invention, the fact that the azimuth loss becomes infinite at a predetermined frequency is used to measure the standard tape for measurement on which the sweep signal is recorded. Since we decided to measure the azimuth angle deviation from the suppression state of the reproduction signal obtained by the stop reproduction with the magnetic reproduction device equipped with the measurement magnetic head, it is necessary to attach a special jig in the state of the drum assembly at the time of assembly. There is an effect that the measurement can be easily and accurately performed without performing.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing conditions under which an azimuth loss becomes infinite.

FIG. 2 is a graph showing the relationship between signal frequency and azimuth loss.

FIG. 3 is an explanatory diagram showing a relationship between a state in which a track on which a sweep signal is recorded is reproduced by a magnetic head and azimuth loss.

FIG. 4 is an explanatory diagram showing a relationship between a magnetic head and an azimuth angle.

FIG. 5 is a graph showing the relationship between dip frequency and azimuth angle deviation.

FIG. 6 is a block diagram showing an example of a recording device for producing a standard tape for measurement.

FIG. 7 is an explanatory diagram showing a relationship between a standard tape track and a measured head locus when measuring an azimuth angle deviation.

FIG. 8 is an explanatory diagram showing an example of a sweep signal waveform reproduced by a magnetic head to be measured.

[Explanation of symbols]

10 ... Recorded track, 12 ... Gap, 14, 15
... magnetic head, 20 ... composite video signal output section, 22 ... signal processing circuit, 24, 30 ... changeover switch, 26 ... sweep oscillator, 28 ... sync separation circuit, 32 ... sync signal generator, 34
... recording / reproducing amplifier, 36 ... rotating drum, 38 ... drum phase control circuit, 40 ... capstan phase control circuit, 4
2, 44 ... Motor drive amplifier, 46 ... Drum motor, 48 ... Capstan motor, 50 ... Standard tape for measurement, 52 ... Magnetic head to be measured, CP ... Control pulse, FA ... Head traveling direction, FB ... Orthogonal to FA Direction, FC ... tape running direction, H1, H2 ... magnetic head,
P0 ... Zero frequency position, P1, P2 ... Dip frequency position, T1, T2 ... Track, W ... Track width, WA,
Wh1, Wh2 ... gap width, .DELTA.V1, .DELTA.V2 ... vertical scanning period, .theta .... azimuth angle deviation, .lambda .... recording signal wavelength.

Claims (1)

[Claims] 1. A magnetic head having a known azimuth angle different from the azimuth angle of the magnetic head to be measured, and a sweep signal in a predetermined frequency range including at least one sweep per track length is recorded with a known track width. The created standard tape for measurement is set on the magnetic reproducing device equipped with the magnetic head to be measured and reproduced with the tape stopped. From the suppression state of the reproduction signal output from the magnetic head to be measured, An azimuth angle deviation measuring method characterized by measuring an azimuth angle deviation.