JPS62262282A - Positioning method for magnetic head of magnetic disk device - Google Patents

Abstract

PURPOSE:To reduce the moving distance, and the moving time of a head, by using a magnetic head assembly in which the space of two data heads is of the integer-fold of the track pitch of a data track, and arranging the two data heads at positions corresponding to cylinder areas divided into two parts. CONSTITUTION:By inputting a new targeted cylinder address to an address difference arithmetic circuit 2 in a head positioning circuit 1, a head 6 is moved according to a difference between the targeted cylinder address, and the present track address, when the cylinder address corresponds to the cylinder area on one side. Also, when the targeted cylinder address corresponds to the cylinder area on the other side, the head 6 is moved by the number of cylinders in which the number of cylinders equivalent to the space between two data heads 13A-13D are subtracted from the difference between the targeted cylinder address and the present track address. In this way, the reduced, and furthermore, a mean moving time is also reduced relatively.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a magnetic head positioning method for moving and positioning a magnetic head of a magnetic disk device to a target track.

[Conventional technology]

FIG. 3 is a block diagram of a magnetic head positioning circuit and mechanism for a conventional magnetic head positioning method. When the cylinder address corresponding to is input, the address difference calculation circuit (2) causes the current address register (8) to hold the servo track address where the current magnetic head is located.
It performs a comparison calculation with the cylinder address and outputs the difference in cylinder addresses and the direction in which the magnetic head moves. Based on these address differences and directions, a target speed generation circuit (4) generates a target movement speed for appropriately controlling the movement of the magnetic head.

On the other hand, a position signal of the servo head (6) is detected by a position detection circuit (γ) based on a servo signal read by the servo head (6) from the recording surface (5). The position signal of the n servo head (6) detected here is input to a speed detection circuit (8), and the moving speed of the head is detected.

The moving speed of the servo head (6) thus obtained and the target speed are input to the speed error detection calculation circuit (9), and a head drive voltage is generated according to the speed difference between the two. This drive voltage is input to the drive circuit and converted into a current that drives the positioner and actuator (2) for moving the head. When the head moves in this way, the servo track address changes due to the change in the position signal of the servo head (6) obtained from the servo signal as described above, and the contents of the current address register (8) are updated. nru. As described above, the head is moved based on the difference between the position of the magnetic head and the target cylinder address, and the head stops when this difference becomes zero.

Data head 08 which then writes and reads data
, (13a) is the data recording surface σ4. (1aa), one piece A is arranged, and it operates integrally with the movement and stopping operation of the servo head (6). For this reason, the servo head (6
) with the servo track address is expressed as shown in FIG. That is, databed α3),
The head address of (13a) is 9101 and %
11, and 1 from cylinder address i=%0'
1''!, the servo track address at each head address is from 1Qt to %KI like the cylinder address.Here, in Fig. 3, the servo recording surface (5) has no servo track address 101
Servo information is written in the servo tracks corresponding to 1Kl to 1Kl, and as described above, the head positioning circuit (1) moves and positions the head toward the servo track corresponding to the target cylinder address input to the circuit (1). Therefore, when the head is positioned at cylinder address 10I in FIG. 3, then if cylinder address %KI is input as the target cylinder address, the servo head (6) will move the servo on the servo recording surface (6). Move from track address %Ol to servo track address %KI 0 In other words, the movement distance of the servo head (6) in this case is the maximum movement distance, and the time required for that movement is the maximum movement time 0 This maximum The travel time is determined by the servo head (6) and data head θ as described above.
'4, (13a) move together, and the fourth
As shown in the figure, the cylinder address is % of the head address.
Since there is a one-to-one correspondence with the servo track addresses in Of and %11, the data head C
19) is equal to the maximum travel time of (13a).

In general, in a magnetic disk device, it is required that the access time to the target data track be as short as possible, and the above-mentioned maximum travel time must also be shortened as much as possible. Furthermore, for the same reason, it is desirable to shorten the average travel time required for the average travel distance.

[Problem that the invention seeks to solve]

Conventional head positioning methods are performed as described above, so in order to shorten the maximum movement time and average movement time, it is necessary, for example, to increase the drive efficiency of the positioner (9) and to reduce the current that drives the positioner (9). Although it is possible to reduce the weight of the actuator and reduce the weight of the actuator, these methods are difficult to achieve in many cases because the overall size and power supply voltage of the magnetic disk drive are limited. It is designed to have a performance that is close to its limit, so there is very little room for improvement, and even if it were possible to improve it, the effect would hardly be expected.

This invention was made to solve the above-mentioned problems, and includes changes to the mechanical part for head positioning control, such as changing the shape and mass of the positioner and actuator, and changing the power supply voltage of the positioner drive circuit. An object of the present invention is to obtain a head positioning method that can shorten the head movement distance without performing the above steps, thereby shortening the head movement time. [Means for Solving the Problems] A head positioning method according to the present invention. In this method, a magnetic head assembly having two data heads that maintain an interval that is an integral multiple of the data track is placed on the data recording surface of a magnetic disk, this data recording surface is divided into two cylinder areas, and the two data heads are arranged in two cylinder areas. -nIII"4 in each of the two cylinder areas, and the head positioning circuit stores the cylinder area information obtained as a result of the cylinder area determination circuit that determines which of the two cylinder areas the target cylinder address corresponds to. In this example, a register is added.

[Effect].

In the head positioning method according to the present invention, once a new target cylinder address is input to the head positioning circuit,
When the cylinder address corresponds to one cylinder area, the head is moved according to the difference between the target cylinder address and the current track address, and when the target cylinder address corresponds to the other cylinder area, the head is moved based on the difference between the target cylinder address and the current track address. The head can be moved by the number of cylinders obtained by subtracting the number of cylinders corresponding to the distance between the two data heads from the difference between the two data heads.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, (13A), (13B) and (15c)
.

(13D) respectively indicate data heads, <15),
(15a) is a magnetic head assembly, α6) is a cylinder area determination circuit, (17) is a cylinder area register, and other symbols are the same as the conventional one shown in Fig. 3, so they are given the same symbols. The explanation will be omitted.

Next, we will explain the operation of the head positioning method.0 When the target cylinder address is input to the address difference calculation circuit (5) via the external connection interface of the magnetic disk device, the current position of the servo head (6) is A comparison operation is performed with the current address register (8) that holds the servo track address to be used, and the head movement is calculated based on the address difference between the two and the direction in which the head moves. A target speed generation circuit (4) generates a target movement speed for appropriately controlling the movement speed. On the other hand, the servo track address of the servo head (6) is detected by a position detection circuit (γ) from a position signal obtained based on a servo signal read by the servo head (6) from the servo recording surface (5). Next, the position signal detected here is input to the speed detection circuit (8), where the moving speed when the head is moving is detected.The moving speed of the head obtained as described above and the above The target speed is input to a speed error detection calculation circuit (9), and a head drive voltage is generated according to the difference in speed between the two.

This voltage is input to the drive circuit αq and converted into a current that drives the positioner α and the actuator for moving the head. When the head moves in this manner, the head position signal detected from the servo signal changes, and the contents of the current address register (8) are updated.

Next, a magnetic head assembly (b) that integrally holds the data heads (13A) and (13E) for writing and reading data holds the data heads (13C) and (13D) as one unit on the same data recording surface. The magnetic head assembly (15a) has a data recording surface (14a)
are placed respectively. Here, the magnetic head assembly (15a) is integrally attached to the actuator (2) together with the servo head (6).
It operates together with the movement and stopping of the servo head (6). Here, the head positioning circuit (1) in FIG.
The relationship between the servo trunk address of the servo head (6) and the target cylinder address input at each head address is shown in FIG.

That is, the head addresses of data heads (13A) and (13B) are 3%0-AI and %0-BIT, and the head addresses of data heads (L5C) and (13D) are 3%0-AI and %0-BIT, respectively. 1-AI, %113#. On the other hand, the cylinder address is up to 10l-%KI, so divide this nine into two equal parts and divide it into %Ol~ //2-11″1 cylinder area and %K/2 # ~%K #-! The relationship between the head address and the cylinder area is as follows: head address %0-AIO and '
1-A#75E%0#-/2-11 Head address %0-B# and %l-B# in cylinder area of i
is assigned to the cylinder area of 1/21-'K I 1 and is n.

On the other hand, in FIG. 1, servo tracks corresponding to servo track addresses %OI to %KI are written on the servo recording surface (5), and the target input to the head positioning circuit (1) as described above. A movement and positioning operation is performed toward the servo track corresponding to the cylinder address. Here, when the servo head (6) is positioned at the servo track address sQe, if the cylinder address %KI is then input as the target cylinder address, the cylinder area %OI-% will be /2-11
J Take Cylinder Area' K/2 Cylinder area determination circuit that determines whether it is the area of #1 to 1KI.
The cylinder area is determined to be the latter cylinder area. At this time, when the cylinder artless was positioned at %O1, the contents of the cylinder area register αη were cylinder area sQl~%K/2-11, so the cylinder area determination circuit α6) changed the register to %/2#~ S.K.
Since the determination is I, the contents of the cylinder area register σ are changed. Address difference calculation circuit (2
) then change cylinder area 730v21 to %KI n
In response to this, the address difference (K-D) is output by subtracting the number of cylinders from the difference in cylinder addresses (K-0=K). Here, the number of cylinders is the data head (13A) and (13A) of the magnetic head assembly (b) in FIG.
This is the number of cylinders corresponding to the head spacing between B) and B).

In other words, the target cylinder address is cylinder area %Qz
~% is in the range of /2-11, the address difference calculation circuit (2) outputs the n address difference obtained from the comparison with the register contents of the current address register (8), but the cylinder area is in the range of % /2 If it is in the range of # to %KI, output the address difference obtained by further subtracting the number of cylinders from the address difference n obtained from the comparison with the register contents of the current address register + a).

By operating as above, the servo head (6
), data head (13A), (13B), (13C)
The maximum number of cylinders that (13D) moves is −D
Therefore, compared to the conventional head positioning method shown in Fig. 3,
) decreases by D. Accordingly, the maximum travel time required for movement also decreases, and the average travel time also relatively decreases.

In the embodiment, the case is shown in which the number of data heads included in the magnetic head assembly and the number of divided cylinder areas are two, but the present invention can also be carried out in the case where there are three or more data heads.

〔Effect of the invention〕

As explained above, according to the present invention, a magnetic head assembly is used which has two data heads and the interval between the two data heads is an integral multiple of the track pitch of the data track. Since the cylinder areas are arranged in correspondence with the two divided cylinder areas, the cylinder address difference to be moved when the target cylinder area corresponds to one cylinder area is reduced by the number of cylinders corresponding to the data head interval. is possible,
As a result, the head movement distance can be shortened, and at the same time, the movement time can also be shortened.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of the configuration and head position for carrying out a head positioning method according to an embodiment of the present invention, FIG. 2 is a correspondence table between cylinder addresses and track addresses of each head, and FIG. 3 is a conventional head positioning method. The configuration of the head positioning method and the head positioning circuit diagram are also shown in FIG. 4, which is a correspondence table between the cylinder address and the track address of each head. (1): Head positioning circuit (2) Near address difference calculation circuit (8): Current address register (4): Target speed generation circuit (6): Servo recording surface (6): Servo head ())
: Position detection circuit (8): Speed detection circuit (9): Speed error detection calculation circuit αQ: Drive circuit (111: Positioner ((2)
: Actuator (13A) to (13D) : Data head side, (14a
): Data recording surface u), (15a): Magnetic head assembly a6)
Niji Linda area determination circuit q7) Niji Linda area register Note that the same reference numerals in the drawings indicate the same or corresponding parts.

Claims (2)

[Claims] (1) It has a first magnetic head and a second magnetic head,
Data is written and read using a magnetic head assembly in which the head spacing in the direction across the data track between the gap of the first magnetic head and the gap of the second magnetic head is an integral multiple of the track pitch of the data track. All cylinder addresses are divided into a first cylinder area and a second cylinder area, the first magnetic head of the magnetic head assembly is placed in the first cylinder area, and the second magnetic head is placed in the second cylinder area. When switching from the first cylinder address of the first cylinder area to the second cylinder address of the second cylinder area, the first cylinder address and the second cylinder address
A method for positioning a magnetic head in a magnetic disk device, characterized in that the magnetic head assembly is moved by the number of cylinders obtained by subtracting the number of cylinders corresponding to the head spacing from the address difference between the cylinder address and the cylinder address. (2) A magnetic head of a magnetic disk device according to claim 1, wherein the magnetic head assembly has three or more magnetic heads, and the data area is divided into three or more cylinder areas. Positioning method.