JPH03288313A - Magnetic recording and reproducing method - Google Patents

Abstract

PURPOSE:To obtain satisfactory reproduced pictures by moving a magnetic head in the breadthwise direction of a track within a range less than the specified ratio of a track pitch after automatically correcting the step of the head, and detecting a magnetic head position, where a reproducing signal is made maximum, within the moving range. CONSTITUTION:The outputs of a detector 25 are respectively measured by a timer 32 and digitally converted by a sampling signal to be inputted through an input/output circuit 28 to an A/D converter 26, and an average value for the 100 pieces of data, for example, is calculated and stored in a data memory 29. Then, an output signal from the input/output circuit 28 to a D/A converter 21 is found out corresponding to the case of making the output signal maximum in these average values. While defining the output signal of the maximum aver age value found out in such a way is defined as V, and signal V is outputted to the converter 21 and the step of the head is corrected. Next, with this V as a center, a head 1 is moved in the breadthwise direction of the track within the range less than the 1/3 of the track pitch and the head position is detected 25 so that the reproducing signal can be made maximum within the moving range. Then, the satisfactory reproduced pictures are obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a reproducing method for a high-density magnetic recording/reproducing device.

[Prior Art] As a conventional magnetic recording and reproducing method, for example, Japanese Patent Publication No. 1-1
The device disclosed in Japanese Patent No. 50967 is known and is explained as follows.

FIG. 8 is a diagram showing the mounting state of the magnetic head, and FIG. 9 is a block diagram showing a conventional magnetic recording/reproducing apparatus.

As shown in FIG. 8, the magnetic head 1 is attached to a rotating drum 3 by a movable element 2 such as a piezoelectric element, and by inputting an electric signal or other signal to the movable element 2, the magnetic head 1 is moved in the direction of the arrow in FIG. As shown in FIG. 9, a playback device that can generate a signal from the detector 8 and the generator 12 includes a detector 8 that detects the output of the magnetic head l, a signal generator 12 that can generate a step-like signal, and a signal generator that generates a step-like signal. An AD converter 18 that converts into a digital quantity and a memory 9 that can store its output
, a computing unit 10 that performs a predetermined operation on the memory contents, and a DA converter 11 that converts the operation result into an analog quantity. 15 is a sampling signal generator, 14 is an amplifier, 13 is reproduction mode switching means, and switches SW1. SW
Operate 2.

When starting playback, first the playback mode switching means 13 operates, and the switch SWI is activated.

SW2 operates as shown by the broken line. As shown in FIG. 10, a step signal generator 12 generates signals in several stages (three stages in this example) in units of fields, and is applied to the movable element 2. The movable element 2 moves the head 1 in the track width direction according to the applied voltage, so the track 5
11, position the head l.
will be scanned. (The applied voltage is not changed while the head 1 scans the track 5 once (approximately 17.ms).) At this time, the reproduction output from the head 1 is at the position of the head l, as shown in FIG. Corresponding characteristic waveforms 16, 17, and 19 are shown. At this time, the step signal voltage and the output waveform 16.1719 are stored in the memory 9 at a predetermined sampling period, and the switches SWI and SW2 are turned OFF.
shall be.

(See Figure 10b).

Now, by associating the applied voltage from the step signal generator 12 with the corresponding head outputs 16, 1719, the amount of curvature of the track 5 can be determined by the calculator 10, as shown in FIG. 13, for example. FIG. 13 shows that the optimal track position is set at the position where the reproduction outputs 16, 17, and 19 from the head 1 are at their maximum, and the computing unit 10 generates a waveform 20 that smoothly connects each point. This is what we seek. In order to improve the accuracy with which the head traces the track with respect to the amount of track curvature, it is necessary to know in advance the maximum reproduction voltage Vd that the head will output as reproduction output. The amount of track deviation may be calculated from the difference between the voltage value) Vd and the maximum value during reproduction, and this difference may be eliminated. Assume now that the maximum value Vrnax is obtained as a signal during reproduction. In this case, if V, -V□, 8 x ε (however, ε is a small value), the head is considered to be tracing almost the track.

The track acidity amount obtained in this manner is stored in the memory 9 again. From point b in Figure 1O, switches SWI, S
W2 is turned off, and a voltage for correcting the amount of curvature of the track 5 is applied to the movable element 2 via the DA converter 11 every time the head 1 scans.

Thereby, the best tracking can be performed without constantly vibrating the head 1.

Incidentally, when the tape running mode changes, a step signal is generated only at the moment of the change (sections c and d in FIG. 10), and a new correction signal is generated in the same manner as before.

In the case of a VTR, the time required for one head scan is 17m5.
Therefore, even if about 10 scans are performed, the step signal generation period is about 170 m5, which is not a particularly problematic length in terms of video.

In the above, the track acidity amount is learned only during the step signal generation period, but as another example, the track acidity amount is learned by correcting the track acidity amount at the beginning of the memory voltage application period b - c in Fig. 6. Compare the head output voltage with the design voltage value Vd and check whether the track bending correction voltage is sufficient. If it is insufficient, superimpose the step voltage on the track bending correction voltage and check the track bending amount again. The correction accuracy may be improved by calculation.

[Problems to be Solved by the Invention] The conventional magnetic recording and reproducing method is as described above, and even if the magnetic tape is recorded by the same magnetic recording device, there are problems such as expansion and contraction of the magnetic tape and changes in the tension of the reproducing device. Therefore, there is a change in track bending over time. Therefore, it is necessary to respond to this change over time.

However, as described in Japanese Patent Publication No. 1-50967, the conventional method deteriorates the image quality for a certain period immediately after the start of signal reading, that is, while the step signal is being generated. In order to follow changes over time, it is necessary to provide a step signal generation period during playback, and the image quality deteriorates each time.

Furthermore, in the case of a general household magnetic recording and reproducing device, for example, the magnetic tape to be reproduced is recorded by various magnetic recording devices, and since there are individual differences in the recording level of each device, the design voltage value Vd cannot be uniquely determined, and the accuracy of track bending correction cannot be improved by comparison with a constant value Vd.

The present invention was made to solve the above-mentioned problems, and it automatically corrects the head level difference at the start of playback.
A magnetic recording and reproducing method that can follow changes in track curvature over time and obtain good reproduced images even for magnetic tapes with different recording levels, without deteriorating image quality during subsequent reproduction. is intended to provide.

[Means for Solving Problem 11] The magnetic recording and reproducing method according to the present invention includes changing the position of the magnetic head once during the period in which the magnetic head is not reproducing the track or once in a plurality of periods during which the magnetic head is not reproducing the track. After the position of the magnetic head is moved in the track width direction by a movable element, the track is reproduced, and the step amount of the magnetic head is calculated from the movement amount of the magnetic head and the reproduction signal at that time, and the step amount of the magnetic head is calculated based on the calculation result. a step of moving the magnetic head during a period when the magnetic head is not reproducing the track, and inputting a first pattern signal based on the initial offset to the movable element using the position moved in this step as an initial offset. Then, while keeping the first pattern as it is, the magnetic head is moved in the track width direction within a range of 1/3 or less of the track pitch, and the reproduced signal at that time is read, so that the reproduced signal becomes maximum within the moving range. Detecting the position of the magnetic head and inputting a second pattern signal necessary for moving the magnetic head to the detected position to the movable element; and adjusting the track pitch while leaving the second pattern as it is. The magnetic head is moved in the track width direction within a range of 1/3 or less, the reproduced signal at that time is read, the position of the magnetic head where the reproduced signal is maximum within the moving range is detected, and the magnetic head is moved at that position. and inputting a third pattern signal necessary for moving the movable element to the movable element.

[Operation] According to the above method, the step of the head is automatically corrected at the start of reproduction, and then the magnetic head is moved in the track width direction within a range of 1/3 or less of the track pitch, and the reproduced signal is adjusted within the moving range. The magnetic tape detects the position of the magnetic head where the magnetic head is at its maximum, updates the corresponding pattern signal one after another, and inputs it to the movable element, so the image quality does not deteriorate during playback and the recording level is different. It is also possible to follow changes in track curvature over time and obtain good reproduced images.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings. In Fig. 1, the reproduction output of the magnetic head (1) is transmitted through the amplifier (24
), the signal is input to a detector (25), envelope-detected there, and input to an A/D converter (26) where it is converted into a digital signal. The output of the A/D converter (26) is transmitted by a microcomputer (hereinafter referred to as microcomputer) (3
3) is input to the input/output circuit (28). Here, A/
The input/output circuit (28) outputs the timing signal sampled by the D converter (26). In addition, the output of the playback mode signal generator (22>) that outputs a signal indicating whether or not the playback mode is in playback mode (hereinafter referred to as PB) is also input to the input/output circuit (28). (hereinafter referred to as H) is the playback mode; otherwise, the low level (hereinafter referred to as L) is the playback mode signal generator (
22). The output of a field signal generator that generates a signal (hereinafter referred to as FD) that changes on a field-by-field basis is also input to the input/output circuit (28) of the microcomputer (33). Here, magnetic head (1)
It is assumed that Hl is the field to be reproduced and L is output from the field signal generator (23) otherwise. Further, the signal output from the input/output circuit (28) is converted into an analog signal by the D/A converter (21), and then amplified by the amplifier (20) and applied to the movable element (2). The microcomputer (33) is a reproduction mode signal generator (22),
Field signal generator (23), A/D converter (26)
Input the signal from the D/A converter (21), A/D
An input/output circuit (28) that outputs signals to the converter (26), a data memory (29) that temporarily stores data, an arithmetic circuit (30) that performs calculations, and a program memory (31) that controls operation commands. It is composed of a timer (32) that measures time.

Next, the operation will be explained.

In FIG. 2(a), when the track recorded on the magnetic tape (4) is (34a), first the magnetic head (1)
A signal V whose position is V is output from the input/output circuit (28), converted to an analog signal by the D/A converter (21), amplified by the amplifier (20), and applied to the movable element (2). The output of the detector (25) at this time is shown in FIG. 2(d). Furthermore, it has been experimentally confirmed that no significant deterioration in image quality is observed even when the magnetic head (1) is moved in the track width direction within a range of ⅓ or less of the track pitch. When tracks are recorded on the magnetic tape (4) as shown in Fig. 7, the track pitch is the width indicated by TP with respect to the track width TW, and if there is no guard band, T
W and TP will match. Here, the amount of movement in this embodiment is assumed to be ±a, (the output signal from the input/output circuit (28) to the D/A converter (21) corresponding to the range ±a is assumed to be ±A). For the mini, we will move it within a wider range of ±2a. Therefore, the magnetic head (
1) outputs signals V+2A, V+A, VA-A and V-2A whose positions are v+2aSv+aSv-a and v-2a from the input/output circuit (28) to the D/A converter (21). At that time, the outputs of the detector (25) are respectively shown in Fig. 2 (b), (c), (e) (f), and these Fig. Of (f), first the signal shown in Fig. 2 (b) is sent to the timer (32).
is measured by the A/D converter (
26) by the sampling signal input to
Digital conversion is performed by the A/D converter (26) at the timing of , the average value is obtained by adding the 10 data and dividing by 10, and this value is sent to the data memory (29) via the input/output circuit (28). ). Figure 2 (C), (
In the case of d), (e), and (f), the average value is similarly determined and stored in the data memory (29). The output signal from the input/output circuit (28) to the D/A converter (21) corresponding to the maximum among these average values is found. Second
In the case shown in FIG. 2(a), the average value is maximum in the case of FIG. 2(d), and the output signal corresponding to this is V. By outputting the signal V obtained by the above operation to the D/A converter (21), the height difference in the head is corrected.

Next, the magnetic head (1) is moved by ±a in the track width direction with this V as the center. Detector at this time (25)
The output from Figure 2 (c) and (d
), (e). These Figures 2 (c), (d) (e
) is measured by the timer (32) and inputted to the A/D converter (26) via the input/output circuit (28), and the sampling signal is input to the A/D converter (26) at the timing of To-79.
The data is converted into digital data by a converter (26) and stored in a data memory (29) via an input/output circuit (28). Next, at each time from To to T9, v+a, v,
The arithmetic circuit (3o) calculates at which position of the magnetic head (1) on v-a the envelope detection signal of the output of the detector (25) is maximum, and the data memory (29)
) is detected from among the data. And Tk (k=o
The signal necessary for the output of the detector (25) to reach its maximum at the time of ~9) (V+A when v10a, V when v,
-a, V-A) is output from the input/output circuit (28) to the D/A converter (21) at the timing of Tk' (k=o to 9) measured by the timer (32). The signal pattern output from the input/output circuit (28) at that time is
It is shown by the solid line in Figure (a). It is necessary to set Tk≧Tk'' in consideration of sample hold in the A/D converter (26), delays in other circuits, response time of the movable element (2), etc. At this time, the detector (25) ) is output from the detection signal shown in FIG. 4(b).The detected signal shown in FIG. ) in the data memory (29).Then, first, the signal pattern in FIG.
-A part is ■, ■ part is V+A, V0A part is V
Change it to +2A. Then, the output of the wave detector (25) at that time is sampled by the A/D converter (26) at a timing of To-79 and stored in the data memory (29) via the input/output circuit (28). The output of the detector (25) when the offset level is changed by -A, which is indicated by the downward arrow in the signal pattern of Figure 4 (a), is also stored in the data memory (29).Then, the data is stored in the data memory (29) by the arithmetic circuit (30). Out of the data in the memory (29), in which of the three cases above (the pattern in Figure 4 (a), when this is changed by 10A or -A) at each time of To-79 is the maximum value? is detected and the output signal at that time is TO°
~ D/A from the input/output circuit (28) at the timing of T9'
Output to converter (21). The output signal pattern is shown in FIG. 4(C). The detected signal from the detector (25) at this time is shown in Fig. 4(d), which shows that a good reproduced signal can be obtained even for a curved track like 34a in Fig. 2(a). Even after repeating the above operation, if the track bend remains 34a, the signal output from the input/output circuit (28) to the D/A converter (21) will follow the signal pattern shown in FIG. 4(c). Without any change, the output of the detector (25) remains as shown in FIG. 4(d), and a good reproduced signal is maintained. Furthermore, even on magnetic tapes recorded with the same magnetic recording device, track bending may change over time due to expansion and contraction of the magnetic tape, changes in the tension of the playback device, etc. It is also possible to maintain good reproduction output by repeating the above operations according to the present invention. For example, when the track bend changes from 34a in FIG. 2(a) to 34b in FIG. 5(a) due to changes over time, the signal pattern shown by the solid line in FIG. The offset level is changed by ±A in the vertical direction shown, and T
It detects in which case the maximum value is reached at each time of o-79, and the output signal at that time is sent from the input/output circuit (28) to the D/A converter (21) at the timing of TO' to T9'.
). The output signal pattern at this time is shown in Figure 5 (
In this case, the detected signal from the detector (25) becomes the solid line shown in FIG. 5(c), indicating that a good reproduced signal can be maintained even if the track curve changes over time.

Next, the operation will be explained with reference to the flowchart shown in FIG. First, at (100), it is detected whether or not the mode is playback mode, and if it is the playback mode, the process moves to (84), and if not, it waits until the playback mode is set. (84) sets V+2A at address 000, V0A at address 001, ■ at address 002, and V-AOO3003 in the data memory (29) whose addresses are set as shown in Figures 3 and 4. TeV
-2A is stored at address 004. Next, at (85>), store O at address X. Then, at (86), store O at address 100.
Remember and initialize. At step (87), the controller waits until the FD falls and detects the beginning of a period in which the head does not reproduce a track. Next, at (88), the contents of address 000, namely V+2A, are output to the D/A converter (21). Then, in (89), the rise of the FD, that is, the point in time when the head starts reproducing the track, is detected, and in (90), the timer (32) is reset and started to begin measuring time. Then, in (91), O is stored at address Y. Next, if (92) waits until time TO is reached, then (93
) adds the input data from the A/D converter (26) via the input/output circuit (28) to the contents of address 100. Then, in (94), 1 is added to the contents of address Y to make it l, and in (95), since the contents of address Y is not lO, the process returns to (92). Similarly, operations (92) to (95) are repeated until the contents of address Y become IO. In other words, the D/A converter (21)
To-T when outputting 00000 address V+2A to
Add all the data sampled in step 9 and get Ioo
This means that it was memorized. Next, in step (96), the contents at address 100 are divided by 10 and stored again at address I00. This means that the average value of the 10 data sampled by To-79 has been calculated. Then, in (97), l is added to the contents of address X to make it 1, and in (98), since the contents of address X are not 5, the process returns to (87). The operations from (87> to (98)) are then repeated until the contents of address X become 5. In other words, V+A stored at addresses 001, 002, 003, and 00404.

When outputting V, VA and V-2A to the D/A converter (21), calculate the average value of each IO data sampled at the timing of TO-T9 and calculate +0110.
This means that it is stored at addresses 2103 and 104. Next, in (99) I 00, 101, 102. I 03 and I
The address OMAX stores the output signal to the D/A converter (21) corresponding to the largest data among the contents of address O4 (000 if the content of address 100 is the largest)
There is OMAX number 00, I. If it is address 01, it is 001, I.
Address 02 is 002. Address 103 is 003, I 04.
If it is an address, 004 is ONAI). In the case of Figure 2 (a), Figure 2 (b), (c), (d),
From (e) and (f), the case of Fig. 2 (d) is determined by the detector (
Since the detection signal of the output of 25) is the maximum, 002 is OM.
AX, and the output of the detector (25) reaches its maximum when it outputs the symbol (■) at address 00202, which means that the head level difference has been corrected.

Next (101) 't' is OMA for addresses 000-009
Memorize the value V-A obtained by subtracting A from the contents of address X, and do the same thing.
Enter the data V+A in the address. Next, (1
02), O is stored at address X in the data memory (29). Then, in step (103), the magnetic head (1) detects whether or not the FD rises, that is, the track to be reproduced has arrived. If a rise is detected, the process moves to (104), and if not, it waits until it becomes a rise. Next (+
In step 04), the timer (32) is reset and then started to start measuring time. Then, in (105), 0 is stored at address Y in the data memory (29). next,
At (106), wait until time TO' is reached. When TO' is reached, at (107) the value V-A stored in advance at 000 is transferred from the data memory (29) to the input/output circuit (28).
It outputs the sampling signal to the D/A converter (21) via (108) and waits until the time TO arrives, and when the time comes, outputs the sampling signal to the A/D converter (26) and inputs the sampled data. Data memory (2) via output circuit (28)
9) is stored in I00. Next, in (110), 1 is added to the contents of address Y, making it l, and in (111), the contents of address Y are 1.
Since it is not 0, the process returns to (106). Hereafter, in the same way (1
Perform operations from 06) to (III) until the content of address Y is 10.
Repeat until. This results in outputting VA, which is the content of addresses 001-009, and storing data sampled at the timing of TI-T9 in addresses IO1-109.

Next, in (113), add l to the contents of address X to make it 1, and (
+13), the contents of the X address are not 3, so the process returns to (102) and the operations from (103) to (113) are repeated until the contents of the X address becomes 3. As a result, 010-019
Output V, which is the content of the address, and store the data sampled at timings T1 to T9 in addresses +10 to 119, and then output V+A, which is the content of addresses 020 to 029, and sample it at timing TI-T9. This means that the data was stored at addresses +20 to +129. In other words, the signals shown in FIGS. 2(c), 2(d), and 2(e) are sampled and stored in the data memory (29), respectively. Next, in step (114), O is stored at address Y. Then, in (115), when the content of addresses I00, 110, and 120 becomes the maximum, the corresponding OMAX
Find Y. In other words, if address +00 is the maximum, it is 000,
r If address 10 is the maximum, set 010. If address 120 is maximum, set 020. ○MAXY tossle. Soshite (116) T (
OMAXY-A) is stored as 0001, and OM
Store the data AXY in 010, (OMAX Y
+A) is stored in 020. Next (117
), 1 is added to the contents of address Y to make it l, and since the contents of address Y are not 10 in (118), the process returns to (115). Thereafter, the operations from (115) to (118) are repeated in the same manner until the content of address Y becomes 10. This allows TO~T9
The corresponding D/A converter (21) when the input signal from the A/D converter (26) reaches the maximum at each time of
Store the output level to addresses 010 to 019, and store the signal obtained by adding an offset of -A and 10A to the above level as 00
This means that they are stored at addresses 0-009 and 020-029. That is, the data for the signal pattern shown by the solid line in FIG. 4(a) is stored at addresses 010-019.

Next, at step (119), the program waits until the FD starts up again, that is, until the next track to be played arrives. If the rising of the FD is detected (120), the timer (32)
Reset and start the time measurement. Next, in (121), O is stored at address Y. And (12
In step 2), wait until the time reaches TOo, and when it reaches TO', in step (123) the contents of address 010 are output from the input/output circuit (28) to the D/A converter (21).

Then, in (124), 1 is added to the contents of address Y to make it 1.

Next, in (125), the content of address Y is not 10, so (1
Return to step 22) and repeat operations (122) to (125) until the content of address Y becomes 10. This allows the signal pattern of Fig. 4(a) to be transferred from the input/output circuit (28) to
/A converter (21). Next, (1
In 26), if PB is H, the process returns to (102), but if it is L, the mode is other than the playback mode, so the process moves on to other processing. When PB returns to (102) at H, it returns to (1
Repeat the operations from 02) to (113) until the content of address X becomes 3. This allows from (114) to (118
) and the output signal pattern data stored in addresses 010 to 019 obtained by repeating operations up to 000 to 009, which are offset by -A and 10A.
The A/D converter (26
) input signal data from addresses 110 to 119, ! at timings TO to T9, respectively. It is stored at addresses 00-I09 and addresses 120-129. And then,
Find a new signal pattern by performing the operations from (114) to (118) and store it in addresses 010 to 019, and then repeat the operations from (119) to (125) to create a new signal pattern in the input/output circuit (28). from the D/A converter (2
1) Output. The output pattern becomes the pattern shown by the solid line in FIG. 4(C). The operations described above (1
Step 26) is repeated until PB becomes L, that is, during the playback mode. Generally speaking, from (84) to (99
> operation to detect the offset amount that maximizes the average value of the output signal of the detector (25), and from (102) to (113)
Signal pattern that is repeated operation up to ±A
The input data from the A/D converter (26) for each case is stored in the data memory (29), and the best new pattern is outputted. The pattern from (114) to (
It is found by repeating operations up to (118), and (11
By repeating the operations from 9) to (125), the new pattern is transferred from the input/output circuit (28) to the D/A converter (2).
1), and if PB is H at (126), return to (102) and repeat the series of operations again.

In the above embodiment, it is output from the input/output circuit (28), converted into analog by the D/A converter (21), and sent to the amplifier (2).
The signal applied to the movable element (2) via the movable element (2) changes in a stepwise manner.Actually, considering the response band of the movable element (2), Figs. If the signal pattern shown in Figure 5 (b) is a signal connected by a smooth curve, the detected signals shown in Figure 4 (b), (d) and Figure 5 (c) will also have a smooth shape rather than a sawtooth shape. becomes. Further, although a microcomputer is used in the above embodiment, hardware may be used instead. In addition, if the change in the detection signal near the entrance of the truck is large, among the processes (107) and (123), the contents of the OXO address and 010 address are output to the D/A converter (21) in (103) and (123). It may be just before (119). Further, if the track bending changes slowly over time, the pattern update interval may be increased by repeating the operations (119) to (125) for outputting a new pattern for a certain period of time. Also, in (101), ooo~009 address, O1O~019 address, 020-0
Although a constant signal is applied to each address 2929, this is not limited to a constant signal, and any signal pattern suitable for the magnetic recording/reproducing apparatus to which the present invention is applied may be applied.

In addition, when correcting the head level difference, the range in which the head is moved is set in 5 steps between V → 2a and V-2a, but this is not limited to 5 steps, and if the number of steps is increased This improves the accuracy of head level difference correction, and if the movement range is within the range from the position where the bottom edge of the playback head is the top edge of the track to the position where the top edge of the playback head is the bottom edge of the track, an effective playback envelope detection signal can be obtained. Therefore, it is not limited to between v+2a and v-2a.

Furthermore, although the difference in level was detected by simply averaging the data at each sampling point, it is also possible to perform weighting for each sampling point and then calculate the average to detect the difference in level.

[Effects of the Invention] As described above, according to the present invention, after automatically correcting the head height difference, the magnetic head is moved in the track width direction within a range of 173 or less of the track pitch, and the reproduced signal is maximized within the movement range. In order to detect the position of the magnetic head and update the corresponding pattern signal one after another and input it to the movable element,
It is possible to follow changes in track curvature over time without deteriorating image quality during reproduction, and to obtain good reproduced images.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an example of the device used in the present invention, Fig. 2 is an explanatory diagram showing recorded tracks and reproduced envelope detection signals, and Fig. 3 shows memory addresses in the data memory. Explanatory diagram, Figure 4 is a diagram showing the output signal pattern from the microcomputer and the envelope detection signal, Figure 5
The figure shows the track when the track bend changes over time, the output signal pattern from the microcomputer at that time, and the envelope detection signal, Figure 6 is a flowchart diagram showing the operation of the present invention, and Figure 7 explains the track pitch. Figure 8 is a diagram showing the mounting state of the magnetic head, Figure 9 is a diagram showing the mounting state of the magnetic head.
The figure is a block diagram showing a conventional magnetic recording/reproducing device.
Figure 11 is a diagram showing the conventional head scanning method, Figure 12 is a diagram showing the output waveform of the head at that time, and Figure 13 is an example of track acidity stored in memory. FIG. 1...Magnetic head, 2...Movable element, 20.24...
Amplifier, 21...D/A converter, 22...Reproduction mode signal generator, 23...Yield signal generator, 25...
Detector, 26... A/D converter, 28... Input/output circuit,
29...Data memory, 30...Arithmetic circuit, 31...
-Program memory, 32...timer In the figures, the same reference numerals indicate the same or corresponding parts. Diagram

Claims (1)

[Claims] By mounting a magnetic head on a movable element such as a piezoelectric element and applying an input signal such as electricity to the movable element from the outside,
In a method of performing magnetic recording and reproducing using a magnetic recording and reproducing apparatus that moves a magnetic head to track a track written on a magnetic tape, the position of the magnetic head is adjusted to the position of the magnetic head during a period when the magnetic head is not reproducing the track. After the position of the magnetic head is moved in the track width direction by the movable element once during a non-reproducing period or during a plurality of periods, the track is reproduced, and the magnetic head is determined based on the amount of movement of the magnetic head and the reproduction signal at that time. a step of calculating the step height of the head, and moving the magnetic head during a period when the magnetic head is not reproducing the track based on the calculation result, and using the position moved in this step as an initial offset based on the initial offset. A first pattern signal is input to the movable element, and the magnetic head is moved in the track width direction within a range of 1/3 or less of the track pitch while keeping the first pattern as it is, and the reproduced signal at that time is detecting a position of the magnetic head where the reproduction signal is maximum within a reading and movement range, and inputting a second pattern signal necessary for moving the magnetic head to that position to the movable element; 1 of the track pitch without changing the second pattern.
The magnetic head is moved in the track width direction within a range of /3 or less, the reproduced signal at that time is read, the position of the magnetic head where the reproduced signal is maximum within the moving range is detected, and the magnetic head is moved at that position. A magnetic recording and reproducing method comprising the step of inputting a third pattern signal necessary for movement to the movable element.