JPS62197968A - Magnetic recorder - Google Patents

Abstract

PURPOSE:To perform the positioning of a head on an object data track in a short time, by reading out in advance a bit of second position information by which a bit of first position information should be corrected with a data head, and storing it as a correction value. CONSTITUTION:A servo head 15 detects the bit of first position information recorded on a servo plane, and at a position signal reproduction circuit 16, a required position signal is separated from a servo signal, and a position deviation between the servo head and a servo track is found at a position error detection circuit 17. Five data heads 11a-11e perform the reproduction of the bits of second position information from corresponding data planes. Obtained bits of position information are changed to the second position error signals at a position detection circuit 13, and the bits of second position information corresponding to each of the data heads are held at hold circuits corresponding to respective head as position deviation signals reproduced and corrected in advance. In this way, since no waiting time is required at the time of obtaining the bit of second position information, the positioning can be obtained in a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in a head positioning method for a magnetic recording device, that is, to an improvement in method (1) for accurately positioning a data head on a predetermined data track.

[Summary of Invention 0] The present invention provides a magnetic recording device that reproduces the F'Lfc interest rate information recorded on the disk surface and performs head positioning while referring to the information. It has position information and 2nd location information on data surface 1, and ejects the second position R information on one side or more of data surface appropriately in Otk state except when starting, and obtains from the first and 20th position information. A signal corresponding to the difference between the data head and the target data track om!iin and the difference in position deviation between the servo head and the servo track,
If necessary, it is stored as a correction groove for each data head, and after switching the data head, the Q
The correction amount corresponding to the new ^ data head is about 1■ in the above frame!
By superimposing the head on the signal for positioning and then recording and reproducing the data, it is possible to accurately position the head on the data track in a short time.

[Conventional technology]

A magnetic recording device l is a magnetic disk on which data is recorded (
It has a conversion system consisting of a magnetic head (hereinafter referred to as the head) that records and reproduces information on the disk.
It is fixed to the mechanism that determines the position. A large number of concentric data recording areas called tracks are provided on the disk, and by moving the head onto these tracks, information is recorded and reproduced between the disk and the head.

Therefore, in order to efficiently and accurately record and reproduce [1],
It is necessary to accurately position the head on the track.

As the track density increases and the track width decreases, more accurate positioning is required. For this reason, position information is recorded on the disk, and the head is moved accurately (on the track) according to the position signal reproduced by the head. Control positioning. Servo method is widely used.

Conventionally, there are several types of servos, but for reasons such as excellent vertical positioning accuracy and short positioning time, one of the recording surfaces of the disk is used to record vertical positioning information for complete positioning control O. Many systems have been adopted in which the remaining 0 sides are used for recording only data. The control-only surface on which only the aforementioned positional information is recorded will be called the servo surface (servo disk surface), and the surface on which only the remaining data will be recorded will be called the data surface (data disk surface).

An example of a mechanism of a magnetic recording device having a servo surface will be described below with reference to Figure 1. A disk having a servo disk surface 1 and data disk surfaces 2cL to 26 is fixed to a main shaft motor 3 and rotates. In the case of this method, the magnetic recording device uses the 2flk type heads 4, which corresponds to the servo surface (called servo head) 4, and the heads (called data heads) 5α to 5e, which correspond to the data surface. . These Q heads are then attached to a support arm 6, and the support arm 6 is movable in the radial direction of the disk, and an M (voice coil motor) 8 is used as its driving motor. The positioning mechanism 7 is fixed to the base 7 Rem 9 and can rotate around the shaft 1 (1) fixed to the base 7 Rem 9. This rotational movement causes the head group to move in the radial direction of the disk. When it is necessary to record and reproduce data on a certain track, drive the 70M9 and position the data head on the target track. Monitor the servo head position and the target track position.
Control and position! ! The data head was secondarily positioned to the target data track via the purchasing section.

However, according to the above method, although it is possible to accurately align the positions of the servo head and the servo track (2), it is not necessarily possible to accurately align the data head and the target data track (Ki).

In other words, misalignment and tilt may occur between the servo head and the data head due to the operation and aging of various parts in the support arm, positioning mechanism, and even the main shaft motor. The servo head may be damaged due to reasons such as the pace frame has a fixed part, or it warps or deforms due to temperature changes, or there is a temperature difference between the stacked disks, resulting in a difference in the amount of thermal expansion. and servo track Oifli
A difference occurs between the position and relative phase of the data head and the target data track.

As a result, even if the servo head is accurately positioned on the target servo track, the data head will deviate from the target data track.

Therefore, in order to solve this problem, 1%
As described in 03, positioning is performed using the first position signal obtained from the servo head, and then the corrected accuracy obtained from the second position signal obtained from the data head is @l
Superimposed on the O position signal.

A method was adopted in which the data head was accurately positioned over the target data track.

[Problem that the invention seeks to solve]

According to the above method, the data head currently in use and the target data track are correctly aligned, but in a magnetic recording device that has multiple data surfaces and data heads, when switching to another head on the same cylinder, different cits may occur. The data track on the data surface and the data head are not necessarily aligned correctly.In the magnetic recording device shown in FIG. 1, the data head 5α on the data surface 2α and the target The data track is correctly positioned and
Even if data is recorded and reproduced, if the current position is maintained on the same cylinder and an attempt is made to record or reproduce between the O data head 5e on another data surface 2e and the target data track, the data will not be recorded. Head 56 is not necessarily positioned correctly.

On the other hand, in order to eliminate the rfLrIk determination error that occurs as described above and perform accurate positioning, the position information on the target data surface to be recorded and reproduced is read out every time the head is switched, even if the O movement between cylinders is not performed. The correction obtained from the servo surface is superimposed on the position signal and corrected, Q1! A method similar to f open 5]-81603 can be considered. However, according to this method, each time the head is switched, the time required for the position information on the data surface to rotate to the data head position and arrive at the data head position is called the waiting time, and during this waiting time, the data surface It is not possible to obtain the positional information of the data head and the target data track is correctly aligned with the data head after switching by correcting the position information on the data surface only after a waiting time. - In the case where only one positional information is recorded per round on the data track as a row, the drying waiting time is equal to the time it takes for the disk to rotate 2 minutes 01 times.A large number of positional information on the data surface is recorded per round. This may reduce the waiting time, but it is not a fundamental solution.

The above-described method of waiting for positional information from the disk surface after switching the head and correcting the positioning has the disadvantage that there is a waiting time of 25 r when switching the head, and extra time is required to read data.

As described above, according to the conventional method, all the data heads and target data tracks corresponding to each data surface are
Since it is impossible to align the positions Iji and Iji, there is a drawback that when the data head is switched, the head position shifts, making it impossible to record and reproduce data correctly. Also, every time you switch the data head! This method has the disadvantage that it takes time to read data, and it does not satisfy the demands for faster data retrieval and faster data transfer, which have been increasing in recent years with the increase in the capacity of magnetic recording devices. Ta.

An object of the present invention is to provide a magnetic recording device that improves the above-mentioned drawbacks.

[Means to solve the problem]

The present invention provides a control signal for positioning the data head on the target data track, which includes a servo disk surface in which the first position information is recorded, and a second ridge position information along with the data area on the data track. a servo head having one or more recorded data disk surfaces and mounted in correspondence with the servo disk surface;
A plurality of 0 data heads are arranged corresponding to the data disk surface, and are used to record and reproduce data and to reproduce the second position information, and the first and second position clear heads. According to the information, in a magnetic recording device having a control unit that determines and controls the data head to the target data track lff1i, the 2nd Q position information on one or more data disk surfaces is stored in a state other than the time of startup. The data head and the target data track are detected from the @2 position signal obtained by passing the road and the first position signal obtained from the servo disk surface on which the @1■ modification information is recorded. Detecting a signal 1 corresponding to the difference between the positional deviation of
when switching data heads.

The correction if corresponding to the data head after switching:
, when positioning is performed superimposed on the first position signal and recording/reproduction is performed, vkK is performed.

[Effect]

According to the present invention, the 20,000 positional information for which the first digit Ii information should be corrected is read out in advance by the data head and stored as a correction value, and when the head is switched, it is obtained in advance for the data head. Since the position of Vh is determined according to the correction value of ml, the above-mentioned waiting time does not exist, and the time required for positioning is short, and it may be possible to move to the second ml! if
With the f-report correction being performed, each data head is accurately positioned on the target data track.

[Implementation row]

A first embodiment of the present invention will be explained below.

Figure 1 shows this example! ! The structure is shown, but in the case of the real 1M series, there is no difference from @Mizogami's conventional model.

The Ugly 2 figure is recorded on the data surface of the real M column and is 9 data and @
This is a conceptual diagram of location information of No. 2, and in this implementation series, JP-A-51-
It is basically the same as the 0 column such as 81603. Data side 2
■A large number of data tracks D1 to Ds and servo tracks 81 to 4 are arranged above, and the boundaries of adjacent servo tracks coincide with the radial center of the data tracks1.
In this embodiment, the servo tracks are placed only at one location on the data track, but there is no problem even if there are servo tracks at two or more locations.

@Figure 3 is the position control circuit O of the magnetic disk drive in this implementation row.
This is a conceptual diagram, and the operation will be explained below.

15 is a servo head, and the legal name 1 is recorded on the servo surface.
Detects the position information of, and in the position signal reproducing circuit 16,
Position detection errors do not occur due to changes in signal amplitude.
After passing through lCaGc, a necessary position signal is separated from the servo signal, and a position error detection circuit 17 determines the position deviation between the servo head and the servo track.

Position information obtained from the data head is similarly processed. The magnetic recording device in FIG. 1 has five data heads.
In Figure 3, there are 5 data heads 11a-11ε. During the period when each head itself is not recording or reproducing data, it appropriately reproduces the 20th # information from the corresponding data surface. The obtained position information passes through the position signal reproducing circuit 12 and becomes a second position error signal in the % position error detection circuit 13.
Furthermore, by taking the difference from the position error signal obtained from the acid 11 information of wXl on the servo surface, the difference between the vertical #L deviation between the data head and the target data track and the position deviation between the servo head and the servo track is calculated. This is the correction amount representing.

This correction amount is held without being outputted by a hold circuit (14α to 14s+) K corresponding to the 9 data heads that reproduces the second position information and does not output it until the correction amount for the 1st Q data head is input. An example of 0 or more that is output for the first time when the head is switched and the corresponding head is selected? I'll give you an explanation.

For example, it is assumed that the data head IIa is not currently in the recording/reproducing state and the data head 11g is selected.

The position information of wE2 detected from the data surface 2α corresponding to the data head 11α is processed by the 1-position signal reproducing circuit 12 and the position error detection circuit 13, and then the data head 1
A hold circuit corresponding to 1α is held at α (14α). If data head 11a is selected, the correction value is output to the next stage, but currently data head 11g is selected.
is selected, the hold circuit ε(14g')
When the primary head is switched and the data head 11α is selected, the hold circuit α outputs a correction value.

As mentioned above, each time the data head is switched, the correction amount corresponding to the new head after switching is switched and output, and is superimposed on the output signal of the OCt error output circuit 17 from the servo surface. This becomes a corrected error signal. While performing phase control, SW is closed, and this 0 signal is applied to the M drive circuit 18GC, and the SW is closed.
By doing 19'kl1Ma, it enters the recording/playback state ^
accurately position the data head on the target data track.

As mentioned above, there are 11
212) The fill information is held in a hold circuit corresponding to each head as a vertical deviation signal that has been reproduced and corrected in advance. After that, each time the head is switched, the correction amount for the new head is output, and the positioning control is performed by correcting the O1 + 2) i1 error signal from the servo head. t-can be minimized. Moreover, the second
Since there is no waiting time as described above when obtaining the fl1 information, positioning can be performed in a short time. Note that the speed control circuit 21 is used for movement between tracks, and is not used for positioning when switching heads.Therefore, for positioning when switching heads, BW is closed and 8W! Do this with the switch open, and when moving between tracks, SW! Speed control is performed with SW closed and SW open, and during the final stage of ml determination control, SW is closed and SW is open.
W! becomes open.

Another implementation column of the present invention Q - shown in FIG. 4. The basic operation is the same as the first implementation column, but the processing of the position signal obtained from the data head is different. For example, when processing the position information of the data head 11α, the position information is processed by the position signal detection circuit 12,
After passing through the position error detection circuit 13, the corrected position error enters the equation-to-balance ratio circuit B. The drying equalization circuit manually inputs the corrected position error signal every time a sampling command is input, holds the new 16 @ O data from the i direction, calculates the 〒average 1fEt of these data, and calculates this oy average. Hold circuit α (14α) corresponding to the direct data head II a
). By averaging the 16 position deviation signals, it is possible to output a position correction signal with less error caused by irregular disc radial direction, equipment deviation, or vibration, improving correction accuracy. The circuit configuration and operation other than this are the same as the implementation column shown in FIG.

In addition, in the above explanation, one correction is calculated for all data heads, and correction is performed for all heads every time the head is switched.However, in the present invention, it is not necessary to calculate the correction r*' for all heads. There is no need to calculate r or make corrections, just perform the necessary head operations.

〔effect〕

As described above, according to the present invention, the amount of correction obtained from the position information of the snore 2 on the data surface is determined and stored in advance for each head that requires correction, and each time the data head is switched, The position error signal obtained from the first position information on the servo surface is corrected and positioned using the correction amount corresponding to the data head immediately after head switching, so no matter which data head is used, the head It is possible to position the target data track correctly and in a short time.

[Brief explanation of drawings]

@1 Figure is a schematic diagram showing the structure of the mechanism part of the embodiment of the present invention,
Figure 2 is a schematic diagram showing the arrangement of data tracks and servo tracks with respect to the data surface according to an embodiment of the present invention, Figure 3 is a diagram showing the circuit configuration of the present invention. FIG. 2 is a diagram showing a circuit configuration of another real tU string according to the present invention. 1...Servo surface 2 (2α~2g)...Data surface 3...Spindle motor 4...Servo head 5 (5α~5g) *Data head 6...Support arm 7...Head positioning @ groove 8... Voice coil motor (M) 9... Pace frame 10... Axis 11 (11α~11e)... Data head α~e12
--Position signal regeneration circuit 13...Position error detection circuit 14 (14α to 14e)+1.Hold circuit 5 to 615
1 servo head 16...Position signal reproducing circuit 17...Position error detection circuit 18@...M drive circuit 19-@V(:MI...Head positioning mechanism section 21φ/Speed control circuit 22Q@Averaging circuit B"ll -a Switch 1 SW No.-Switch 2 Snow D1~D s a a Data Track B-Be/Data Track Top O Servo Toratsu Applicant: Seiko Epson Shishiki Co., Ltd. Figure 1

Claims (1)

[Claims] As a control signal for positioning the data head to the target data track, a servo disk surface on which first position information is recorded, and a surface on which second position information is recorded together with a data area on the data track, or a servo head that has a plurality of data disk surfaces and is attached to the servo disk surface, and a servo head that is attached to the data disk surface to record and reproduce data and the second position information A magnetic recording device comprising one or more data heads for reproducing data, and a control section for controlling the positioning of the data heads to a target data track based on the first and second position information. The second position information on the data disk surface is appropriately detected in a state other than startup, and the obtained second position signal and the first position information are obtained from the servo disk surface on which the first position information is recorded. A signal corresponding to the difference between the positional deviation between the data head and the target data track and the positional deviation between the servo head and the servo track is detected from the first position signal, and each signal is calculated as a correction amount corresponding to each data head. In the case where the correction amount is stored for each data head, and when the data head is switched, the correction amount corresponding to the switched data head is superimposed on the first position signal for positioning and recording/reproduction is performed. A magnetic recording device characterized by: