JPS60613A - Method for detecting position of magnetic head of magnetic recording device and master tape used for it - Google Patents

Abstract

PURPOSE:To grasp quickly and accurately a position of a magnetic head to a reference position by detecting contents of recording of a master tape by means of a magnetic head of a magnetic recording device and detecting a position of the magnetic head to the reference position from a timewise change of the detected output within a prescribed period. CONSTITUTION:The master tape is loaded to the magnetic recording device. Then the magnetic recording device is operated and a signal recorded on the 1st and 2nd signal tracks 35, 36 of the master tape is detected by a magnetic head 18. The timewise change of the signal level depends on the relation of position of the magnetic head 18 to signal tracks 35, 36, i.e., the relation of position among the reference track 32, side tracks 33, 34 and the magnetic head 18. Thus, the relative position of the magnetic head 18 to the tracks 32, 33 and 34 at that time is confirmed by observing the form of a reproducing signal displayed on a cathode ray tube.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for detecting the position of a magnetic head in a magnetic recording device using a magnetic tape, and a master tape used in the method for detecting the position.

[Technical background of the invention]

Conventionally, data is recorded or reproduced by running a magnetic tape in the longitudinal direction in contact with a magnetic head, and by moving the magnetic head along the width direction of the magnetic tape, data is recorded or reproduced on each track divided into multiple stages. Magnetic recording devices for reproduction have been developed. The mechanism for moving the magnetic head in the width direction of the magnetic tape is called a tracking mechanism, and its mechanism will be explained based on FIGS. 1 and 2.

First, a capstan 2 and a pinch roller 3, which are driven by a motor (not shown), are installed on the pace 1. A row 57-arm 4 holding the pinch roller 3 is rotatably held on the pace 1 about a pin 5, and the roller arm 4 is driven by a solenoid (not shown) via a link 6. Further, a pulse motor 9 is fixed under the pace 1, and a motor gear 10 driven by the Nockles motor 9 and gears 11 and 12 are provided on the upper surface of the pace 1 and are successively meshed with each other.

Next, frame 1 is placed on pace 1 so as to cover gear 12.
A feed screw 14 that rotates integrally with the gear 12 is rotatably held in the frame 13, and a guide shaft 15 is fixed in parallel to the feed screw 14. A head base 19 that holds a guide plate 17 that contacts a magnetic tape 16 and a magnetic head 18 is held on the guide shaft 15 so as to be vertically movable and rotatable. A window 20 is formed in the guide plate 12 to allow the magnetic head 18 to come into contact with the magnetic tape 16.

An arm 21 protruding from one side of the head base 19 has a locking pawl 2 that engages with a threaded portion 22 of the feed screw 14.
3 is fixed by a fixing plate 24, and a leaf spring 25 is screwed to the other side of the head base 19. A felt 26 impregnated with lubricating oil is fixed to this leaf spring 25.

Therefore, the magnetic tape 16 is fed by the capstan 2 and the pinch roller 3 for recording or reproduction, but when 90 rotations of the nockle smoke are transmitted to the feed screw 14, the locking pawl 23 engages with the threaded portion 22. Therefore, the head base 19 moves along with the magnetic head 18 in the vertical direction, that is, in the width direction of the magnetic tape 16, according to the rotating direction of the motor 9.

The width of the magnetic tape 16 is 12.7 rwm (1,(
2 inches), and within this, there are 150 to 2
00 M tracks are provided. The magnetic tape 16 runs at a speed of about 5 mly+ee while contacting the magnetic head 18.

In such a magnetic recording device fli, the magnetic tape 1
It is necessary to set the digit 1d of the signal recording section (signal track section) recorded in No. 6 to a certain reference position.

Conventionally, this alignment method involves using a magnetic recording device that has been adjusted separately, and reproducing a master tape on which a certain reference signal is recorded on the signal track at the reference position using a four-way magnetic recording device.

Then, the reproduction output level was added to 1lill, and the upper and lower 1t of the magnetic head were set so that the reproduction level indicated the maximum value. That is, in FIGS. 1 and 2, after the pulse motor 9 is driven to rotate and the magnetic head 18 is moved to the signal track position 1 indicating the maximum reproduction output,
Make fine adjustments using mounting screws, etc. Then, this position is set as a reference position and is applied to the control circuit of the /4'rus motor 9.

[Problems with background technology]

However, the above-described magnetic head position recommendation cavity method has the following problems.

In other words, it is necessary to estimate how far the magnetic head is from the reference position from the reproduction output level, so during adjustment work, move the magnetic head up and down while checking the actual amount of deviation! 9JJ fine W11 adjustment cannot be carried out. Also,
It is not possible to immediately determine whether the magnetic head is located above or below the reference position. Therefore, there is a problem in that the adjustment work time increases.

゛Also, when confirming that the position of the magnetic head where the playback output level reaches the maximum value corresponds to the true reference position, or when checking the error distance from the reference position, it is necessary to move the magnetic head to the reference track of a new magnetic tape. Record the semi-signal. and,
The deviation from the reference position of the magnetic head was confirmed by developing this recorded image and checking the recorded position with a microscope, etc. However, according to this method, each time a measurement is made, Cut out the magnetic tape,
Since the image must be developed, there is a problem in that the time required for confirmation work increases.

[Purpose of the invention]

The present invention has been made based on the above circumstances, and its purpose is to quickly and accurately determine the position of the magnetic head relative to the reference position, and to facilitate the adjustment of the magnetic head position. An object of the present invention is to provide a method for detecting the position of a magnetic head of a magnetic recording device that can be carried out quickly and in a short time, and a master tape used in this method.

[Summary of the invention]

In the master tape of the present invention, a reference position is set at an arbitrary position in the width direction of the tape, and a pair of signal tracks having the same width and a predetermined gap are formed around the reference position at constant intervals in the width direction. It is formed in a meandering manner.

Furthermore, in this invention, the recorded content of the master tape is detected by a magnetic head of a magnetic recording device, and the position of the magnetic head with respect to the reference position is detected from the time change of the detection output within the certain period. ing.

[Practice of the Invention ψ11] FIG. 3 is a track arrangement diagram of a master tape used in a magnetic head position detection method of a magnetic recording device according to an embodiment of the present invention.

Is this master tape 12.7? This reference line 31 has a width of Il+K (V2 inches)' and extends in the longitudinal direction through the reference position set at the center in the width direction.
A base iV4) rack 32 with a width of 65 μm centered on is provided. First and second side tracks 33 and 34 are provided above and below this reference track 32 with a gap of 65 μm, which is the same width as the width of the reference track 3 . The widths of the first and second side tracks 33 and 34 are 65 μm, the same as the reference track 32.

Furthermore, the center line of the gap between the first side track 33 and the reference track 32 is a constant period of length L in the longitudinal direction of the tape, and the first side track 33 and the reference track 32 A first signal track 35 having a meandering sine wave shape is also provided. This first signal track 3
The width of the first signal track 35 is 65 μm, the same as the reference track 32, and a sine waveform signal of a constant frequency and a constant level is recorded on this first signal track 35. Note that the length L of the above-mentioned fixed period is set to 2.5 m or less.

Further, the first No. 48 track 35 is aligned with the center line of the gap between the second side track 34 and the reference track 32.
A second signal track 36 having the same O/W configuration is provided parallel to the first signal track 35. Therefore, the width of the gap between the first signal track 35 and the second signal track 36 is 65 μm, as is clear from FIG. These signals are recorded in advance by periodically varying the vertical position f of the magnetic head 18 in the reference magnetic recording device ff shown in FIG.

Using the master tape stored in this way, unR11
'a! The method of detecting the position of the magnetic head of the magnetic recording device (Ii) will be explained.

First, the master tape shown in FIG. 3 is installed in the magnetic recording apparatus shown in FIG. Then, the magnetic recording device is operated, and the magnetic head 18 records the first and second data on the master tape.
Detect the signals recorded on signal tracks 35 and 36 of . The detected signal is then displayed using a cathode ray tube oscilloscope (not shown), with the vertical axis representing the signal level and the horizontal axis representing time t. Therefore, for example, the levels of the composite signals detected from the first and second signal tracks 35 and 36 by the magnetic head 18 having the same 65μlet 1jjW as the reference track 32 are as shown in FIGS.
It is displayed as a periodic function of period T as shown in FIG. This period T corresponds to the constant period length L in FIG. 3, and since the tape speed is 5 m/see in the embodiment, it is less than 0.5 se6. Note that the starting point a of the period T on the tape is made to coincide with the starting point a of the period T on the cathode ray tube using the illustrated trigger device.

These No. 48 level temporal variations are determined by the positional relationship between each signal track 35, 36 and the magnetic head 18, ie, the reference track 32.36, as shown in FIG. Side track 33.
It depends on the positional relationship between J4 and the magnetic head 18. For example, as shown in Figure 4(,), questions a-5 and questions d-e
When the IA signals with the same period between (a) are displayed, it is confirmed that the magnetic head 18 is located at position A in FIG. 5, that is, on the first side track 33.

The signals between a and b and between de and e are the first reproduced signal 35a reproduced from the first signal track 35, and the maximum level thereof is at point a and point 0 (point a). occurs in Further, as shown in FIG. 4(b), when an oath signal is displayed between b and d in addition to the signal shown in FIG. 4(a), the magnetic head 18 is moved to position B in FIG. It is confirmed that it is located at the center of the reference line 31 of .

In this case, the signals of question a-5 and d-e 1iiJ are conversely the second reproduction signal 36a reproduced from the second signal track 36, and the signal between b-d is the first reproduction signal 36a.
It is 5a. Then, the first and second reproduction signals 35t
The maximum values of s and 36a occur at points C, , (,), respectively. If a signal is displayed between b and d as shown in FIG. 4(c), the magnetic head 18 will be in position C in FIG.
The above signal is the second reproduced signal 36a, and the maximum value occurs at point C. In addition, Fig. 4(d) and Fig. 41561 (
In the case of the shape shown in e), the magnetic heads 18 are in the positions E and E in FIG.
3 and a part of the second side track 34 can be confirmed.

In addition, in the reproduced signal shape displayed on the above-mentioned cathode ray tube, the track width and the width of the magnetic head.

If the intervals between tracks are different, each playback signal 35h,
Some of the 36h waveforms overlap and are separated by axes, but
The basic shape, such as the position showing the maximum value, does not change.

Therefore, it is displayed on the cathode ray tube (1J, raw i 11
By observing the shape of the number, the relative position of the magnetic head 18 to each track 32, 33, 34 at that time can be confirmed.

The amount of deviation of the magnetic head 18 from the reference line 31, that is, the distance between the magnetic head 18, the center line, and the reference line 31, can be determined from the relative values of the levels of the reproduction signals 35a and 36a in FIG. Specifically, in FIG. 4, each reproduced signal 35 at position C and position a(e) within period T
Compare the levels of a and 36a. For example, in the same figure (a
), considering the full scale as one track, C
The point is “O” and 1. (The 01 point is '1' of the reproduced signal 35a.
It is #. Therefore, the magnetic head 18 is
, i.e. side track 33.
It is located above. In addition, in the case of the same figure (b), point C is "1" of the reproduced signal 35a, and point a(e) is "1" of the reproduced signal 35a.
It is "1" of 6h. Therefore, the level difference is zero and the deviation of the magnetic head 18 is zero. Furthermore, in the case of (d) in the same figure, the point C is 10". The point (,) is the reproduced signal 35".
0.5" of m. Therefore, the magnetic head 1B is nr quasi-height 31 by 0.5)7 ts 2i"; 1 (D
This shows that the side track 33 has shifted upward. In this way, the amount of deviation of the magnetic head 18 is determined by the two reproduction signals 35.
It can be easily determined from the level ratio of h, 36&.

Then, based on the magnetic head 18, 'f"ft1J' s 1
When adjusting the position, the magnetic head 18 is adjusted to the position shown in FIG.
After moving the shape i to 11f, where it is closest to the state shown in Figure 4 (b), adjust the height m: J using mounting screws, etc. so that the levels of point C and point a (e) are equal. .

Then, use that position as the reference position and do the above! Set to control 011 circuit of Le Smoke 9.

The width of each track on the master tape is 65 μm.
However, the width of the magnetic head 18, the detection accuracy, etc.
A range of about 55 to 75 μm is desirable.

If this magnetic head position detection method is used, [3fi
The positional relationship of the head 18 with the reference line 3) of the master tape is shown in Figure 4 (-) to () on the cathode ray tube of the oscilloscope.
The harm time (real time) is displayed as shown in ).

Therefore, in an unadjusted magnetic recording device, the position fr4 of the magnetic head J8 (when performing adjustment, the magnetic head 18
You can immediately judge whether the magnetic head 18 is located above or below the reference line 31, and also check the amount of deviation of the magnetic head 18 and finely adjust the vertical movement of the magnetic head 18 from the orange. Therefore, the tatami preparation work can be carried out easily and in a short time.

Furthermore, since the distance of the magnetic head 18 from the reference line 31 can be easily calculated from the level ratio of the reproduced signals at the 0 point and point a(e) on the cathode ray tube, the deviation of the magnetic head 18 The confirmation work time can be significantly reduced.

〔Effect of the invention〕

As explained above, according to the present invention, a master tape in which a pair of signal tracks meandering in the width direction in one short circle J around a reference position are arranged in parallel with each other at a constant interval, is used. The position of the magnetic head relative to the reference position is detected by detecting the shape and level of the reproduction signal of the signal track within the certain period.

Therefore, it is possible to provide a magnetic head position detection method that allows the position of the magnetic head to be grasped quickly and accurately, and further allows adjustment of the magnetic head position to be carried out easily and in a short time, and a smart table f used in this method.

[Brief explanation of drawings]

Figure 1 is a cutaway plan view showing the recording device, and Figure 2 shows the main parts of the recording device.
．． Figures 2l-S3 are signal track arrangement diagrams that can be arranged on a 1h% master tape as an example of the present invention.
a) (b) (c) (d) (0) relates to an additional example of the present invention (; Bekarishi Recording Test 1: j''s 11'' air head position i1..4 detection method e ii: r, Initial A No. 4 External Diagram for Clarification, Figure 5 Magnetic Head Arrangement for Explaining the Stud Output Method 4-1: ≦1. 2...Pinch Roller , 3... Capstan, 9...
・Pulse motor, 16...Magnetic tape, 18...I4 (air head, 31...Reference line, 32..., 11
', ill track, 33rd...' first track, 34th... :2nd track, 35th.
...First signal track, 36...Second A track, 35B...Aisoi A of beat 1; No., 36a...
・) Reproduction No. 46 of 1gi 2. Figure 4 (a) (b) □ (a) Figure 5

Claims (2)

[Claims] (1) In a magnetic recording device that uses a magnetic head to record and reproduce data on a magnetic tape that runs while in contact with the magnetic head, a reference position is determined at an arbitrary position in the width direction, and the reference position is set as the center. Using a master tape formed by meandering a pair of signal tracks with the same width and a predetermined gap between each other at a constant period in the width direction, the recording infield of this master tape is detected by the magnetic head, and the detected output is detected. ! of the magnetic head based on the time change within the fixed period of ! J! , a magnetic head position detection method for a magnetic recording device, the method comprising detecting the position relative to the S position. (2) A reference position is determined at an arbitrary position in the width direction, and a pair of signal tracks with the same width and a predetermined gap are formed around the reference position by meandering in the width direction at a constant period. A master tape used in a magnetic head position detection method for a magnetic recording device, characterized in that: