JP2735312B2 - Head disk assembly of disk device, method of manufacturing the same, and head positioning control method of disk device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head disk assembly of a disk drive, a method of manufacturing the same, and a head positioning control method of the disk drive, and is particularly suitable for high-speed track positioning of a head. The present invention relates to a head disk assembly of a disk device, a method of manufacturing the same, and a head positioning control method of the disk device.

[Conventional technology]

In general, head positioning control for positioning a head on a track on a disk includes a seek control mode in which the head is moved to a target track position using the head traveling speed as a control target, and a head control mode in which the relative position between the head and the track is controlled. There is a track following control mode for positioning at the track position. A plurality of heads corresponding to a plurality of data surfaces are provided on a single head carriage, a positioning signal is recorded on the plurality of data surfaces, and read out to perform positioning. , The head positioning system
In general, if the displacement between the head and the target track (cylinder) is less than or equal to 1/2 of the track pitch, the head is controlled by the following control mode to perform the positioning of the head. Further, in the above-described data surface servo type disk device, the seek control mode is always executed once when the positioning target cylinder composed of a set of tracks having the same number or the same radius is changed, and thereafter the control in the following control mode is performed. It is carried out.

[Problems to be solved by the invention]

In the prior art described above, even if the target cylinder of the head is a cylinder adjacent to the cylinder where the head is currently positioned, control is always performed in the seek control mode, and then control is performed in the following control mode. It is configured to be. Therefore, even when the head is moved to an adjacent cylinder, as in the case where the head is moved over an interval of two or more cylinders,
Control in the seek control mode is always performed, which is one of the causes of a decrease in system throughput.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems of the related art, and when positioning control is performed on a shilling adjacent to a cylinder in which a head is currently positioned, without performing control in a seek control mode, the following operation is performed. An object of the present invention is to provide a head positioning control method, a head disk assembly, and a disk in a disk device that enable positioning only by control in a control mode.

[Means for solving the problem]

The head disk assembly of the disk device of the first invention has a plurality of data surfaces, records a positioning signal on each data surface, reads out the recorded positioning signal,
The present invention is applied to a disk device for positioning a plurality of heads integrally provided for each data surface on the same head carriage.Especially, each head is based on the same cylinder on each data surface. It is characterized in that it is provided so as to be relatively displaced by a predetermined distance in the radial direction.

Further, the head disk assembly of the disk device of the second invention has a plurality of data surfaces, records a positioning signal on each data surface, reads out the recorded positioning signal, and integrates each of the data on the same head carriage. The present invention is applied to a disk device for positioning a plurality of heads provided corresponding to a data surface, and the track of the same number on each data surface is relative to a radial direction of the data surface by a predetermined distance. Is formed so as to be deviated in position.

Further, a head positioning control method for a disk drive according to the third invention has a plurality of data surfaces, records a positioning signal on each data surface, reads out the recorded positioning signal, and integrally integrates the same head carriage. The present invention is applied to a disk device for positioning a plurality of heads provided corresponding to each data surface. In particular, when the first head is positioned at a certain track with a zero off-track amount, the first head is positioned at the track. By selecting a track having an off-track amount smaller than 1/2 of the track pitch with respect to an adjacent track and performing only the following mode control, the selected head is positioned at the adjacent track. .

Further, a method of manufacturing a head disk assembly for a disk drive according to a fourth aspect of the present invention has a plurality of data surfaces, records a positioning signal on each data surface, reads the recorded positioning signal, and transfers the positioning signal to the same head carriage. The present invention is applied to a disk device for positioning a plurality of heads integrally provided for each data surface, and after writing a servo signal on each data surface, a plurality of heads integrally provided on the same head carriage. To give relative displacement,
It is characterized by providing a relative difference in the amount of off-track between heads.

Further, the method of manufacturing the head disk assembly of the disk device according to the fifth invention has a plurality of data surfaces, records a positioning signal on each data surface, reads the recorded positioning signal, and transfers the positioning signal to the same head carriage. It is applied to a disk device that positions a plurality of heads provided integrally for each data surface, and writes servo signals on tracks of the same track number on each data surface by a predetermined number of pits in the disk radial direction. By shifting the heads, a difference in the amount of off-track is given relatively to a plurality of heads.

[Action]

According to the first and second aspects of the present invention, there is provided a head disk assembly of a disk device in which an off-track amount is relatively shifted between heads. And the third
According to the invention, when the head disk assembly according to the first and second inventions receives a seek command from a higher-level device to an adjacent cylinder accompanied by head switching, without performing control in a seek control mode, The head is positioned on the adjacent track only by controlling the ing control mode. Therefore, high-speed head positioning can be performed.

Further, according to the fourth and fifth aspects, it becomes possible to manufacture the head disk assembly of the disk device according to the first and second aspects.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to examples shown in the accompanying drawings.

FIG. 1 is a sectional view showing an embodiment in which the present invention is applied to a head disk assembly (hereinafter, referred to as HDA) of a magnetic disk device. In FIG. 1, 1a, 1b, 1
c and 1d indicate a one-sided head, a two-sided head, a three-sided head, and a four-sided head, respectively, and 2a, 2b, 2c, and 2d indicate one-sided, two-sided, three-sided, and four-sided heads, respectively.
The (n-1) th track on the surface is shown. Also, in the figure, 3a, 3b, 3c, 3d indicate an n-th track, and 4a, 4b, 4c,
Reference numeral 4d denotes tracks (n + 1) of one, two, three, and four surfaces, respectively. Further, 5 indicates a head carriage,
6a, 6b, 6c, and 6d indicate first, second, third, and fourth data surfaces, respectively, 7 indicates a spindle, and 8 indicates a motor.

FIG. 6 is a sectional view showing an HDA of a conventional magnetic disk drive, and the same parts as those of the embodiment shown in FIG.

According to the first embodiment shown in FIG. 1, when the one-surface head 1a is located directly above the n-th track 3a on the one surface and there is no positional deviation, that is, when the off-track amount is zero, The head 1b, the three-sided head 1c, and the four-sided head 1d each have two sides n
Track 3b, 3rd track nth track 3c, 4th track nth track
As shown in the figure, the off-track amount is set so that the off-track is 1/4, 2/4, and 3/4 times the track pitch in the direction of the (n-1) th track. The heads 1a to 1c are offset. This offset setting is shown in FIG.
As shown in the cross-sectional view of the HDA, the servo signal is written as before, and the head carriage 5 of the HDA, which has no off-track amount offset between the heads, is deformed unequally in the direction parallel to the data plane. This is done by adding. This deformation can be accurately realized by using not only a mechanical method but also an electro-mechanical conversion by a piezo effect.

FIG. 2 shows that the tracks on each data surface have a track pitch of one another without deforming the head track 5.
An example is shown in which cylinder offsets between heads are set by shifting by 1/4, 2/4, 3/4 times, and the same parts as those shown in FIG. 1 are denoted by the same reference numerals. The offset setting shown in FIG. 2 is applied to the case where external positioning control is performed on the head carriage 5 by the laser photometry method at the time of writing a servo signal.
b, every time the writing is sequentially switched to the nth track 3c on the third surface and the nth track 3d on the fourth surface, the head carriage 5 is moved to (n-1).
It can be realized by moving in the direction of track No. by 1/4 times the track pitch. It can be easily understood that the embodiment shown in FIG. 2 and the embodiment shown in FIG. 1 can be set exactly the same with respect to the head-to-head offset amount of the track (cylinder).

In the above-described first and second embodiments, for example, when the one-side head 1a is writing data on the n-th track on the first side, a command for writing data on the fourth (n-1) -th track by the four-side head 1d is issued. Is issued, in the conventional example shown in FIG. 6, the four-side head 1d is moved to the four-side (n-1) -th track 2d.
In the first and second embodiments, it is only necessary to perform the following control of the four-side head 1d to the four-side (n-1) th track 2d. No seek control is required.

FIG. 3 is a block diagram showing one embodiment of a head positioning control system according to the present invention. In FIG. 3, 11 is a data surface, 12 is a head carriage and a head, and 13 is a VCM.
(Voice coil motor), 14 is a position converter, 15 is a VCM drive amplifier, 16 is a control mode changeover switch, 17 is a head positioning controller, 18 is a seek control system, 19 is a speed error amplifier, 20 is a speed converter, 21 Is a deceleration curve generator, 22 is a difference counter, 23 is a track crossing counter,
24 is a track following control system, 25 is a position error amplifier, 26 is a compensation circuit, and 27 is an off-track amount head-to-head offset learner.

In the data surface servo type disk device, a data surface servo signal is written on each surface of the data surface 11.
Therefore, the off-track amount and off-track direction of the track closest to the head can be determined from the level difference between the two types of servo signals read by the head. Regarding the following control for the target track, the controllable range is ideally up to the off-track amount smaller than 1/2 of the track pitch for the off-track in both directions. VCM13 is V
The head is moved in the cross-track direction on the data surface 1 by moving the head carriage and the head 12 in response to the output of the CM drive amplifier 15. The position converter 14 generates a position error signal indicating the off-track amount and the off-track direction from the servo signal from the head during the read operation. In the control mode of the head positioning control system, a track following control mode in which a position error signal is controlled and an off-track of less than half the track pitch is controlled, and a seek operation is controlled by controlling a head moving speed. There is a seek control mode, and the input of the VCM drive amplifier 15 is switched to each mode by the control mode switch 16. The head positioning controller 17 controls each block of the head positioning control system based on an operation head positioning command from a host device. The operation relating to the present invention will be described later with reference to FIGS.

The seek control system 18 engages in the seek control mode operation, and the speed error amplifier 19, the speed converter 20, the deceleration curve generator 2
1, Difference counter 22, Track crossing counter 23
Consists of The speed converter 20 receives the position error signal from the position converter 14 and outputs a speed signal indicating the head moving speed. The track traversing counter 23 receives the position error signal from the position converter 14 and counts the number of traversing tracks of the operating head, that is, the number of moving tracks. The difference counter 22 counts the number of remaining required moving tracks up to the target track indicated by the head positioning controller 17 based on the number of moving tracks, and then the deceleration curve generator 21 responds to the approach of the target track of the head. Generates a target speed signal with appropriately decreasing characteristics. By subtracting the speed signal from the speed converter 20 and the target speed signal from the deceleration curve generator 21, a speed error signal for the target speed is created, and a control mode changeover switch is passed through the speed error amplifier 19.
Sent to 16.

The track following control system 24 is engaged in the track following mode, and includes a position error amplifier 25, a compensation circuit 26, and an off-track amount head-to-head offset learning device 27. Off-track amount Head-to-head offset learner 27 is VC
The amount of off-track head-to-head offset is learned by observing the output of the M drive amplifier 15, and the input is switched to the input of the position error amplifier 25 via the compensation circuit 26 immediately before performing the operation head change until the operation head change. A position error signal equivalent to half the off-track offset between the front and rear heads is added. Therefore, during this time, the head carriage performs a following operation at an intermediate position between before the head change and after the head change. The output of the position error amplifier 25 is sent to the control mode switch 16. The head positioning controller 17 receives a seek and head change command from the host and switches the mode to the seek control mode or the track following control mode by the control mode changeover switch 16, and also a difference counter.
22 and off-track amount head-to-head offset learner 27,
It controls the compensation circuit 26. These operations will be described below with reference to FIGS.

FIG. 4 is a head positioning controller shown in FIG.
17 is a flowchart showing a process performed when a track change command is received from a host device. When the head positioning control system is in the track following control mode, a track change command including a seek command and a head change command is transmitted to the head positioning controller 17.
(Step 401), the presence / absence and type of the seek command and the head change command are determined (step 402, step 403).

If it is determined in step 402 that the head change does not include a command, the mode is switched to the seek control mode to seek to the target track (step 40).
5), and then return to the track following control mode (step 406).

If there is a head change command in step 402 and it is determined in step 403 that no seek command is included, the off-track amount is set to 1 / off of the head-to-head offset.
The intermediate position following is performed by feeding forward the position error signal equivalent to twice to the track following system (step 409), and then the head is changed to the target head (step 410). Move to the following control for the track.

If it is determined in step 402 that a head change command is included, and if it is determined in step 403 that the command is a seek command for performing one cylinder seek, the determination in step 404 is performed. In step 404,
The value obtained by subtracting the off-track amount head-to-head offset for the track with the target cylinder number from the track pitch is
It is determined whether or not the track pitch is equal to or less than 1/2 times and is within the following control range. If it is determined that the following control is possible, the process of step 409 (intermediate position following) is performed without activating the seek control, and then the head is changed and the control is shifted to the following control of the target track. Yes (Step 41
0).

In step 402, a head change command is included. In step 403, a value obtained by subtracting the off-track amount head-to-track offset for the track of the target cylinder number from the seek or track pitch of two or more cylinders is one cylinder outside the following control range. If it is determined that the seek is performed, the mode is switched to the seek control mode to seek the target cylinder (step 407), and thereafter, the mode is returned to the track following control mode (step 40).
8) Then, a head change is performed via intermediate position following (step 409) (step 410), and the process shifts to following track following control.

FIG. 5 is a flowchart showing the operation of the off-track amount head-to-head offset learning unit 27 shown in FIG. The off-track amount head-to-head offset learning device 27 has difficulty in accurately arranging the heads 1a, 1b, 1c, 1d by a し て track pitch in FIG. 1, and the track 3a in FIG. , 3b, 3c, 3d, it is difficult to form a disk by accurately shifting by a 1/4 track pitch.Therefore, the respective off-track amounts and head-to-head offset amounts are obtained in advance and input to the compensation circuit 26. And enables accurate following control.

As shown in FIG. 5, the first head is seeking the 0th cylinder of First there are four heads 11, by following operation (step 502), the output data V ₁ of the VCM drive amplifier 15 at that time taken (Step 503). Next, the same operation is performed for the remaining three heads, and output data V ₂ , V ₃ , and V ₄ of the VCM drive amplifier 15 are collected (step 503).
Next, the difference (V ₂ −V ₁ ) between the output data V ₁ and V ₂ of the VCM drive amplifier 15 of each head is multiplied by the head movement amount per unit VCM drive output to obtain the off-track amount and the head-to-head offset amount. Is calculated (step 506). Next, step 505,5
The same operation as in step 06 is performed for all combinations of four heads, and the amount of off-track between the heads and the offset between heads are calculated (step 504).

〔The invention's effect〕

Since the present invention is configured as described above, it has the following effects.

By setting the off-track amount of each head to the offset between the heads, in seeking to an adjacent cylinder with a head change, there is a cylinder skew time that is several times larger than the head switching skew time.
Head positioning can be completed only by track following control without performing track pitch seek control.
In particular, even when performing continuous seek over the entire capacity of the disk, depending on the setting of the track switching sequence, all seeks can be completed substantially with track following control, so that the total seek time can be reduced to several tenths.

Further, in the present invention, the minimum step of the movement of the head carriage is the off-track offset amount pitch which is a fraction of one track pitch with respect to the conventional one track pit, so that noise during continuous seek is greatly reduced. be able to.

[Brief description of the drawings]

1 and 2 are sectional views showing an embodiment of a head disk assembly of a disk drive according to the present invention. FIG. 3 is a position embodiment of a head positioning control system for executing a head positioning control method of the disk drive according to the present invention. 4 and 5 are flowcharts showing the operation of the embodiment shown in FIG. 3, and FIG. 6 is a sectional view showing an embodiment of a head disk assembly of a conventional disk device. 1a: One-sided head, 1b: Two-sided head, 1c: Three-sided head, 1d: Four-sided head, 2a: One-side (n-1) track, 2b: Two-sided (n-1) Track No.) 2c Track 3 (n-1) Track 2d Track 4 (n-1) Track 3a Track 1 Track n 3b Track 2 Track n 3c ... Track 3 nth track 3d Track 4 nth track 4a Track 1 (n + 1) track 4b Track 2 (n + 1) track 4c Track 3 (n + 1) track 4d ... Track 4 (n + 1) track 5... Head carriage 6a... 1st data face 6b... 2nd data face 6c... 3rd data face 6d. ... Spindle, 8 ... Motor, 11 ... Data surface, 12 ... Head carriage and head, 13 ... VCM (voice coil motor), 14 ... Position converter, 15 ... VCM drive Dynamic amplifier, 16: Control mode changeover switch, 17: Head positioning controller, 18: Seek control system, 19: Speed error detector, 20: Speed converter, 21: Deceleration curve generator, 22: ... Difference counter, 23 ... Track crossing counter, 24 ... Track following control system, 25 ... Position error amplifier, 26 ... Compensation circuit, 27 ... Off-track amount head-to-head offset learning device.

Claims (5)

(57) [Claims] A plurality of data surfaces, a positioning signal is recorded on each data surface, the recorded positioning signal is read out, and a plurality of data surfaces are integrally provided on the same head carriage so as to correspond to each data surface. In a disk device for positioning a head, each head is provided in a state where it is relatively displaced by a predetermined distance in the radial direction of the data surface with reference to the same cylinder on each data surface. A head disk assembly for a disk device. 2. A plurality of data surfaces, wherein a positioning signal is recorded on each data surface, the recorded positioning signal is read, and a plurality of data surfaces are integrally provided on the same head carriage so as to correspond to each data surface. In the disk device for positioning the head, the same number tracks on each data surface are formed so as to be relatively displaced by a predetermined distance in the radial direction of the data surface. Head disk assembly for disk drive. 3. A plurality of data surfaces, a positioning signal is recorded on each data surface, the recorded positioning signal is read out, and a plurality of data signals are provided integrally on the same head carriage so as to correspond to each data surface. In a disk device for positioning a head, an off-track amount between a certain head and a track opposed thereto is different from an off-track amount between another head and a corresponding track. When the first head is positioned on a track where the off-track amount is zero, a head whose off-track amount with a track corresponding to a track adjacent to the track is smaller than 1/2 of the track pitch is used. By selecting and controlling only the following mode, the selected head is positioned on a track corresponding to the adjacent track. And a head positioning control method for a disk drive. 4. A plurality of data surfaces, a positioning signal is recorded on each data surface, the recorded positioning signal is read out, and a plurality of data signals are provided integrally on the same head carriage so as to correspond to each data surface. In a disk device for positioning heads, after writing a servo signal on each data surface, a relative position deviation is given to a plurality of heads integrally provided on the same head carriage, and a relative off-track amount between the heads is provided. A method for manufacturing a head disk assembly of a disk device, wherein 5. A plurality of data surfaces, a positioning signal is recorded on each data surface, the recorded positioning signal is read out, and a plurality of data signals are provided integrally on the same head carriage so as to correspond to each data surface. In a disk device for positioning a head, by writing a servo signal on a track having the same track number on each data surface at a predetermined pitch in the disk radial direction, a difference in off-track amount between a plurality of heads is relatively increased. And a method of manufacturing a head disk assembly for a disk device.