JPS5826106B2 - Jikihetsudoichigimesouchi - Google Patents

Description

[Detailed description of the invention] The present invention relates to a magnetic head positioning device.

In general, devices with various system configurations have been proposed and put into practical use as magnetic head positioning devices, among them a track-following type that uses a magnetic head to read position information pre-recorded on a magnetic disk surface and performs positioning as a position servo signal. With the advent of magnetic head positioning devices, their performance, especially track density, has greatly improved.

However, the above-mentioned condition for improving the track density cannot be achieved unless the head width of the magnetic head is physically narrowed.

For this reason, in recent years, by applying thin film technology and integration technology, a narrow track head block, that is, an integrated magnetic head, which has an extremely narrow head width and integrates a plurality of magnetic heads, has been developed and put into practical use. A positioning servo head is added adjacent to the integrated magnetic head, making use of the feature that a plurality of magnetic heads can be arranged at extremely narrow intervals. A method has been proposed in which the integrated magnetic head, that is, a plurality of magnetic heads, is simultaneously positioned using the readout signal as a servo signal.

However, due to the structure of the integrated magnetic head, the number of turns of the conductor for generating magnetic flux, which is included in the magnetic head, is generally only a few turns at most. In order to generate sufficient magnetic flux to accurately and reliably magnetically record information, a write current of several amperes is required in the conductor, and when reading information, the output from the integrated magnetic head is similar to that of a conventional magnetic head. Normally, the output is extremely small compared to the output of

On the other hand, even when the adjacent magnetic head, that is, the data head, is writing or reading information, the positioning servo head naturally reads position information pre-recorded on the magnetic disk surface and performs positioning as a position servo signal. Must be.

In particular, when writing information, as mentioned above, a write current having a current value of several amperes and varying at a constant frequency determined by the recording method, that is, generally an extremely high frequency, flows through the conductor, so The positional information read by the servo head results in an extremely large amount of noise, that is, crosstalk noise.

Therefore, the magnetic head positioning device adopting the above method is
Add a filter circuit to remove the noise, or
The data head and positioning servo head must be separated by a distance sufficient to ensure that the influence of the noise on the position information is within tolerance; the former complicates electronic circuitry, reduces reliability, and It has the disadvantage of being expensive, the latter obviously being an essential disadvantage in terms of increasing track density.

Furthermore, in order to further improve the track density, when a magnetic head with a narrow head width is used as the servo head, the positional information is more strongly affected by the noise Q, that is, the S/N is significantly reduced. There was also the drawback that not only highly accurate positioning but also positioning itself was impossible.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to eliminate the above-mentioned drawbacks, to provide a system with a relatively simple configuration, without deterioration of reliability, to be inexpensive, to use an integrated magnetic head, to be equipped with novel means, and to be improved. An object of the present invention is to provide a track-following type magnetic head positioning device.

According to the present invention, in an integrated magnetic head for arranging a plurality of data heads, one positioning servo head is installed at each end of the arrangement direction, and a positioning servo head is selected for writing or reading data. The positioning servo head having a larger distance from the selected data head is always selected, that is, the selected data head belongs to the head group on the left half of the integrated magnetic-rad in the arrangement direction. In the former case, the positioning servo head is selected to be installed at the right end of the integrated magnetic head, and in the latter case, the positioning servo head is installed at the left end. This is a track following type magnetic head positioning device that reads position information recorded on the disk surface and positions the integrated magnetic head as a position servo signal. The number of heads is N,
Further, if the distance between the data head selected for writing or reading information in the integrated magnetic head and the selected servo head is S, then PN≧S≧PN/
2 (N: even number) or PN≧S≧P (N-1)
/2 (where N is an odd number), and by appropriately setting the number N of heads, the influence of the noise generated when writing information on the position information read by the servo head will be within the allowable value. The data head and the servo head can be separated by a distance sufficient to .

Therefore, with a relatively simple system configuration, it is possible to perform high-precision positioning without reducing reliability, inexpensively, and without reducing the number of tracks per surface of the magnetic disk, thereby increasing the track density. It is possible to achieve significant improvements.

Therefore, the object of the present invention can be fully achieved.

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an embodiment of the integrated magnetic head for a track-following magnetic head positioning device according to the present invention, and is an enlarged view of the surface facing the magnetic disk surface.
l...--...-+Hn is data head, SL, S
R is positioning servo head, IH is data head H6
, Hl, .
Integrated magnetic heads with L and SR installed, P, δ, and n+1 are data heads H6, Hl, . . ., respectively.
...represents the arrangement pitch, head width, and number of heads of Hn.

FIG. 2 is a block diagram of an embodiment of the present invention. The integrated magnetic head in this embodiment is n-15 in FIG. 1, and in the same figure, Ho, Hl, .
..., H15 is an array of 16 data heads,
SL and SR are data heads H6°H, l...
Positioning servo heads installed on both left and right ends of ・－■, 5, IH is data head Ho, H, ・ , ・
---- An integrated magnetic head comprising servo heads SL and SR, 1 and a head selection circuit.

2 and 3 are data heads H8, Hl,...
-, H, 5 and servo beds SL, SR form data tracks and servo tracks on the magnetic disk surface; 4 is an inverting amplifier with a gain of 10; 5 is a positioning means;
L and AR are analog switches that connect and disconnect the outputs of the servo heads SL and SR, respectively, ioo and io1゜102.10
3 and 104 are signal lines, and the data heads Ho, H□, . . .
15, the head number expressed in binary of the desired data head selected for writing and reading information is given to the head selection circuit 1, and the selection circuit 1 selects the desired data head. Information written to or read from the data track 2 is input/outputted to a write/read circuit (not shown) through the signal line 104.

At this time, the signal lines 100, 101, 102, and 103 each have a head number of 23, 22, 21, etc. expressed in binary.
It corresponds to the digit of 2°.

As a result, “On” 111n 1 ++ “1” or “I
When a signal of IT * 011 n 011"0 is given, the data head with head number 7 or 8 will be selected, respectively.

By associating the signal line with the digit of the head number in this way, the signal on the signal line 100 is
Crab Gumi desired data head is data head H8,H
It can be determined whether the head belongs to the left-right head group among the left-right head groups among l, . . . ---, , H15.

That is, when the signal on the signal line 100 is 1"', the desired data spatula 11 are sent to the head Ho, H1゜.
-.-2H15 belongs to the right half of the head group, and when the signal is 0'', it belongs to the left half.

Taking advantage of this, in the former case, the data head H8,
Hl.

-・-1--...H15's leftmost servo head SL,
In the latter case, data heads H8, Hl, etc.
If the configuration is such that the rightmost servo head SR of H15 is selected, it is possible to select the positioning servo head that is located at a greater distance from the desired data head.

Now, for analog switch AL, the signal on signal line 100 is 1.
According to "'" and "0", the analog switch AR is connected and "disconnected" respectively, and since the signal on the signal line 100 is applied to the analog switch AR via the inverting amplifier 4 with a gain of 10, the signals are connected and disconnected according to "1" and O". When , they become "disconnection" and "contact", respectively.

Therefore, from the control means, not shown now, head number 10
data head selection command, that is, signal line 100°101
．． 102 and 103 respectively "1""0'',"1","
When a signal of 0'' is applied, the analog switch AL and the analog switch AR are connected and disconnected, respectively, and the position information recorded in advance on the servo track 3 is read out by the servo head SL, and the analog switch AL is turned on. The signal is fed back to the positioning means 5 as a position servo signal, and the integrated magnetic head is positioned in accordance with this servo signal.

Since the integrated magnetic head IH in this embodiment has n=15 in FIG. 1, as is clear from FIG. The servo head SL, which belongs to half the head group, is the positioning servo head with head number 10, which is located at a larger distance from the data head.

Similarly, from data heads H6, Hl, . . . , H15 of the integrated magnetic head IH, the distance from the data head selected for reading and writing information is always large. You can choose the side positioning servo head.

Therefore, if the arrangement pitch of the data heads and the number of heads are respectively P and H, and the distance between the selected data head and the positioning servo head corresponding to this data head is S, then as described above, at least 5= PN/
2 (N: even number) or S = P (N = 1)/2
(N: odd number), and by appropriately setting the number of data heads, that is, n + 1, the influence of noise generated when writing information on the position information read out in the above →\not can be reduced to a permissible value. The data head and the servo head may be separated by a distance sufficient to allow the data head and the servo head to enter the servo head.

Note that, as is easily understood from the above content, the double line represents a mechanical connection.

As described above in detail about the operating principle of the embodiment of the present invention, it is possible to reduce the number of tracks per surface of a magnetic disk using a relatively simple system configuration, without reducing reliability, and by inexpensive means. Therefore, it is possible to realize a track-following magnetic head positioning device using an integrated magnetic head with high accuracy and high track density.

Although the present invention has been described in detail above, it is obvious that modifications can be made within the L range without departing from the spirit of the present invention, and the above description does not limit the scope of the present invention.

[Brief explanation of drawings]

FIG. 1 shows an embodiment of the integrated magnetic head for a track-following magnetic head positioning device according to the present invention, and is an enlarged view of the surface facing the magnetic disk surface, Ho. Hl, -------, Hn is the data head, SI,
, SR is the positioning servo head, IH is the integrated magnetic head, P is the arrangement pitch of the data heads, δ is the head width of the data heads, and n+1 is the number of data heads. FIG. 2 is a block diagram of an embodiment of the present invention, with Ho, Hl
, ---------, H15 is the data head, SL. SR is a positioning servo head, IH is an integrated magnetic head, 1 is a head selection circuit, 2 is a data track, 3 is a servo track, 4 is an inversion amplifier, 5 is a positioning means, 1
00, 101.102°103.104 are signal lines.

Claims (1)

[Claims] 1. In an integrated magnetic head positioning device in which a plurality of data heads are arranged and one positioning servo head is installed at each end in the arrangement direction, a head selection circuit is provided for writing or reading data. At,
Select a data head, divide the selection signal of the data head into two, one through an inverting amplifier, and the other without going through an inverting amplifier, and two servo heads are respectively connected to the two servo heads. configured to be supplied to the analog switch of
The head selection circuit always selects the positioning servo head with a larger distance from the selected data head, and furthermore, the selected positioning servo head selects the position recorded in advance on the magnetic disk surface. A track following type magnetic head positioning device characterized in that the integrated magnetic head is positioned by reading out information and using the information as a position servo signal.