JPS62298974A - Head positioning control method - Google Patents

Abstract

PURPOSE:To eliminate a wasteful time to detect a recording track which is an object and to attain the efficient operation by providing two servo sectors at the symmetrical position in the radius direction and executing the servo control once to the half turn of recording media by servo information written in the servo sector. CONSTITUTION:A servo selector is composed of the first servo sector S1 and the second servo sector S2, and both are provided at the symmetrical position concerning the center of a magnetic disk 1 so as to divide a data zone into two. The result to execute the servo control from a servo signal F in the first servo sector S1 can be confirmed by a servo signal F in the second servo sector S2, when a head is at a fine track position by the confirming action, tracking is executed as it is, when the head is not yet at the fine track position set beforehand, the position control is executed again, and the result is confirmed by the servo signal F in the next servo sector S1 and therefore, the above- mentioned actions are executed.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] This invention relates to a recording head device in an information recording medium drive device that drives an information recording medium to record/reproduce information. 1-Regarding a positioning control method for a rack.

[Conventional technology]

Various types of disk drives are known for recording and/or reproducing information by rotating an information recording medium, for example, a disk-shaped magnetic recording medium (hereinafter referred to as a magnetic disk). However, it is especially small and has a lot of information. ) Disk drive devices, also called hard disk devices, are often used for devices that require 5ffi. This hard disk drive rotates a magnetic disk, which has a magnetic recording layer formed on the surface of a hard disk, at high speed, and makes a magnetic head levitate above the surface of the magnetic disk to perform recording/reproduction.

An example of this pillar disk drive is shown in FIG. In the figure, the disk drive device includes a magnetic disk 1 for recording information, a magnetic head 2 for recording/reproducing information on the magnetic disk 1, and a direct drive motor (not shown) for rotationally driving the magnetic disk 1. Below, D
A head drive mechanism 4 for moving the magnetic head 2 to a predetermined track on the magnetic disk 1; A base plate 5 that becomes a heath,
It mainly consists of a printed circuit board 6 on which a motor drive circuit, a control circuit, etc. are formed, and a frame (not shown) for attaching this printed circuit board 6 to the base plate 5.

In this magnetic disk device, the magnetic disk 1 is
In order to perform double-sided recording on one magnetic disk 1, there are four n-air henodes 2 in total, one on each side, and one on the swing arm 8 of the head drive mechanism 4. The head drive mechanism 4 is attached via a support spring in the form of a handle.The head drive mechanism 4 includes a swing arm 8, a steel belt 9 attached to a part of the swing arm 8, and an intermediate portion of the steel belt 9 wound around the swing arm 8. The stepper motor 11 is made up of a pulley 10 and a stepping motor 11, and the pulley 10 around which the steel belt 9 is wound is inserted into and fixed to the drive shaft 12 of the stepping motor 11, and the stepping motor 11 is moved. Accordingly, the swing 7-m 8
can be pivoted about the rotation axis 8a.

Magnetic disk 1. Magnetic head 2. Swing arm 8. The casing that houses the steel belt 9, pulley 10, etc.
Consisting of the base plate 5 and a top cover (not shown), gaskets are used at the contact area between the base plate 5 and the top cover and at the mounting area of the stepping motor 11 to maintain airtightness, and magnetic fluid is used at the shaft of the DD motor. is filled. Further, a shutter 17 is provided on the antimagnetic head mounting side 8b of the swing arm 8 so as to protrude outward. Furthermore, the airtight chamber 5 of the base plate 5
A photointerrupter 18 is provided as an outside sensor on the a side, and an insertion path 18a of this photointerrupter 18 is provided as an outside sensor.
The shutter 17 is arranged so as to be loosely inserted therein. In this conventional example, when the magnetic head 2 reaches the O track j on the outer periphery, the shutter 17 blocks the optical path formed in the insertion path 18a of the photointerrupter 18.

[Problem that the invention seeks to solve]

By the way, when moving the magnetic head 2 using the stepping motor 11 as described above, it becomes difficult to position the head as density increases. In other words, in hard disk drives, since the expansion coefficients of the materials inside the drive differ, there is a problem called thermal off-track where the position of the magnetic head 2 relative to the track shifts due to temperature changes. In a hard disk drive, if -i is equal to 40 (ITP I), it becomes difficult to position the magnetic head 2 without using a servo.

One of the control methods using this servo is JP-A-57-86.
There is an invention disclosed in No. 910. This invention uses one data-masked servo sector containing track centerline servo control data that can be successively output by the head to position the head from servo information once per revolution of the magnetic disk. ing. therefore,
In this type of servo control system, servo information is embedded in only one location per revolution, so after moving the head, it is necessary to wait for rotation until the servo information is read.

Another control method using servos is to use the innermost and outermost tracks as dedicated servo tracks. This method uses the inner diameter (In5i-de Dia
meter ), outside diameter
This is an abbreviation of ID-OD method. In this system, the disk device first tracks the outer servo tracks, and then makes fine adjustments so that the outer servo tracks are in the center of the tracks. The head is then moved toward the inner servo track. At this time, head%
The number of step pulses of the IX M i stepping motor is counted, and when the head reaches the inner servo track, the head positioning mechanism performs precise positioning so that the head is in the center of the track. Then, during precise positioning of each servo track, the positioning mechanism learns the amount of correction needed to find the center of the track. Once you know the amount of this correction,
Information about the number of step pulses required to move between the outer and inner tracks and the amount of microstep correction required on each servo track allows the positioning mechanism to calibrate the exact position of each track. ing.

However, with this method, the positioning mechanism has to repeat the calibration procedure every time a positioning error occurs, so if this happens frequently, a lot of time is wasted that is not directly related to recording/playback. Therefore, the utilization efficiency of the disk drive device decreases. Also, once the head is on the data track, there is no guarantee that the head will be held in the correct position since there is no means for readjustment.

This invention was made in view of the problems of the prior art as described above, and its purpose is to reduce the rotational waiting time after moving the head until reading the servo information, and to reduce the wasted time for positioning. An object of the present invention is to propose a head positioning control method that can provide an efficient disk drive device with less noise.

[Means for solving problems]

In order to solve the problems faced by the prior art and achieve the above object, the present invention provides a recording medium drive device that writes or reads signals to or from a recording track on an information recording medium via a head device. In the method of positioning the head device with respect to the recording track, first and second servo sectors in which servo information corresponding to each track is written are formed at radially symmetrical positions of the information recording medium, and the head device is rotated by half a rotation. Each time the head device reads servo information, the signal level of the read servo information is compared to control the drive voltage supplied to the motor for moving the head, and the head device is positioned at a fine track position with respect to the recording track. It's Nishide.

[For production]

According to the above means, the head device reads servo information every half rotation of the recording medium, detects the position of the head device with respect to the recording track, and detects when the positional deviation of the head device with respect to the recording track exceeds a preset range. In other words, when the read signal levels are compared and the difference or ratio exceeds a preset level, the drive voltage supplied to the motor for moving the head is controlled according to the level, and the recording track is moved. It can be positioned in a fine track position. Since this operation is performed periodically every half rotation, it is possible to maintain a good fine track position T at all times on average.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

1 to 5 are for explaining the present invention in detail. FIG. 1 is a block diagram showing a control system of a disk drive device according to an embodiment, and FIG. 2 is a block diagram showing a recording track of a magnetic disk. FIG. 3 is an explanatory diagram showing the write state of a servo signal, FIG. 3 is an explanatory diagram showing areas of a magnetic disk, FIG. 4 is a block diagram showing an example of a servo circuit, and FIG. 5 is a disk drive device for explaining index detection. FIG.

Further, the disk drive device itself is the same as the conventional example shown in FIG. 6, and in the following explanation, the same reference numerals are given to components that are the same or can be considered to be the same as those of the conventional example.

In FIG. 1, the control system of the disk drive device controls a DD motor 3 that rotates a magnetic disk 1 and a stepping motor 11 that swings a swing arm 8, and also sends and receives signals to and from a head amplifier 21. The driving circuit 22 and the magnetic helad 2 cause the S to be
It mainly consists of a servo circuit 23 that processes the servo information amplified by the nodal amplifier 21 and sends an electric signal related to surf control to the drive circuit 22, and a controller 25 that controls the drive circuit 22 via an interface 24. The controller 25 and the host computer 26 are connected by a bus 27, and receive signals detected by the magnetic head 2 or
It is now possible to process signals sent to

FIG. 3 shows the servo sectors and data zones formed on the magnetic disk l. A magnetic disk L is, for example, a thin aluminum plate coated with a magnetic coating, and has an inhibit zone I on its innermost circumference where no data is written, and a data zone and a servo sector (servo zone) on its outer circumference. It is divided into two directions.

The servo sector consists of a first servo sector SI and a second servo sector S2, both of which are provided at symmetrical positions with respect to the center of the magnetic disk 1 so as to divide the data zone into two. The data zone consists of a first data zone DI located downstream of the first servo sector SI with respect to the rotational direction R of the magnetic disk l, and a second data zone D2 located downstream of the second servo sector S2. For example, 6 from the outermost recording track.
Recording tracks T are provided inside and outside the 00 tree.

As shown in FIG. 2, the first and second servo sectors St and Sz each receive the same servo signal F at positions equidistant from each recording track T with respect to the center line C in the longitudinal (circumferential) direction. They are written alternately in a staggered manner depending on the frequency. In this case, the same (writes with Dm head 2, so
The track width of the servo signal F and the recording track T matches the length of the gear G of the magnetic head 2, and off-track occurs when the position of the gap G of the magnetic head 2 deviates from the desired recording track T.

Furthermore, in this disk drive, since servo sectors are formed at two locations as described above, it is necessary to provide internal indexes at two locations.

To deal with this, for example, as shown in FIG.
A magnet (hereinafter referred to as a PC magnet) is installed as a pulse generating means on the outer periphery of the rotor 3a of the D motor 3.
40 is attached, and the magnetic change from this PG magnet 40 is applied to each of the positions near the outer periphery of the rotor 3a of the DD motor 3 and opposite to each other symmetrically with respect to the rotation center of the DD motor 3. A detection means (hereinafter referred to as PG sensor) 41a such as a coil or a Hall element is provided.
, 41b and are used as first and second internal index signals IN, , INK. Therefore, the first and second internal index signals IN, , INZ are 180 degrees out of phase.

first and second internal index signals IN,;

As shown in FIG. 2, IN corresponds to the first and second servo sectors S, , S, respectively, and the PG sensor 41a
When the first internal index signal IN is detected, the magnetic head 2 is write-protected and the servo signal F is detected.
It reads out. Then, the first internal index signal IN
Counting starts when , is detected, and when a preset number of outputs is detected, an external index signal ETN is sent to the host computer 26 side. This external index signal EIN indicates the start of the first data zone D1, and recording/reproduction is performed from the detection position of this external index signal EIN. A second servo sector S2 exists at a position where the magnetic disk l has rotated 180 degrees,
This second servo sector S2 is detected by a second internal index signal IN2 obtained by detecting a change in the magnetic field caused by the PG magnet 40 using the PG sensor 41b. When this second internal index signal IN2 is detected, a preset count number (
time), and when the counted number elapses, it enters the second data zone D2. Upon further rotation of 180 degrees from this position, the first internal index signal IN is obtained by the PG sensor 41a, indicating that one rotation has been made from the first internal index signal position.

Next, the operation of the disk drive device configured as described above will be explained.

In this type of disk drive device, the excitation phase and excitation voltage of each recording track T and the stepping motor 11 are stored in advance in a control means such as a microcomputer, and the correspondence between the recording track T and the rotation angle of the stepping motor 11 is established. The position of the magnetic head 2 is determined by selecting the rotation angle, that is, by controlling the magnetic phase and excitation voltage.

Therefore, during operation, the drive circuit 22 selects one of the recording tracks T7 to be recorded/reproduced based on a command from the host computer 26.

In the process of tracking the recording tracks T and l, the gap G of the magnetic head 2 becomes the first servo sector S in FIG.
1, the staggered servo signals are read out, and as shown in FIG.

When the output from the comparison circuit 30 exceeds a preset level, a servo control signal is sent from the servo amplifier 31 to the drive circuit 22, and the excitation voltage of the stepping motor 11 is controlled in accordance with the servo control signal. I is carried out. As a result, the gap G becomes larger than the recording track T, l.
It will be located at a fine track position.

The time it takes for the magnetic head 2 to detect a servo signal, compare the servo signals, correct the position, and converge to a fine track position and stabilize is approximately 3.
m sec. On the other hand, the time required for one rotation of the magnetic disk 2 is approximately 16.67 m at 3600 rpm.
5ec, the next servo signal F (in this case, the servo signal F written in the second servo sector S7) is read out immediately after the servo signal F is read out and stabilized. Thereby, the result of servo control from the servo signal F in the first servo sector S can be confirmed by the servo signal F in the second servo sector S2. As a result of this confirmation operation, if it is at the fine track position, tracking is performed as it is; if it is not yet at the preset fine track position, position control is performed again, and the servo signal at the next first servo sector S is Perform the operation of confirming with F. In other words, with this control method, the servo signal is read once every 1/2 rotation, and servo control is performed as necessary.There is no substantial waiting time for reading servo information, so efficient servo control is possible. This makes it possible to maintain a fine track position at all times.

In the above embodiment, a hard disk drive that rotationally drives a hard magnetic disk was used as an example, but it is also possible to write servo information on the recording medium side and perform tracking control based on this servo information. Needless to say, it can be applied to everything.

〔Effect of the invention〕

As is clear from the above description, the present invention is structured such that two servo sectors are provided at symmetrical positions in the radial direction, and servo control can be performed once every half rotation of the recording medium based on servo information written in the servo sectors. According to the invention, since the convergence time for position correction of the head device and the waiting time until reading servo information are almost the same, it is possible to perform servo control 2n intermittently without substantial waiting time, and the head device can adjust the position. Since the servo information is written in some of the recording tracks to be recorded, there is no wasted time for detecting the target recording track, and a disk drive device that can be operated efficiently can be provided.

[Brief explanation of drawings]

1 to 5 are for explaining a disk drive device according to an embodiment of the present invention. FIG. 1 is a block diagram showing a control system, and FIG. 2 is a block diagram showing a magnetic disk recording track and a servo signal. Figure 3 is an explanatory diagram showing the area of the magnetic disk, Figure 4 is a block diagram showing an example of a servo circuit, Figure 5 is a bottom view of the disk drive, and Figure 6 is a conventional diagram. FIG. 2 is a partially cutaway perspective view of essential parts showing a specific example of a disk drive device from FIG. 1... Seisho Qi Disc, 2... (1 Ki to Nodo, 3
...DD motor, 8...Swing arm, 11...
・Stepping motor, 21...Head amplifier, 22
...Drive circuit, 23...Servo circuit, Dl...
First data zone, D2...Second data zone, F...Servo juice signal, Sl...First servo sector, S! . . . second servo sector, T . . . recording track, IN. IN, ・・・Internal index signal. Figure 2 Figure 3 1 S2 I

Claims (2)

[Claims] (1) In a recording medium drive device that writes or reads signals to or from a recording track on an information recording medium via a head device, in a method of positioning the head device with respect to the recording track, the information recording medium is First and second servo sectors in which servo information corresponding to each recording track is written are formed symmetrically with respect to the center in the radial direction of the medium, and the servo information is read out by a head device every half rotation. A head positioning control method comprising comparing signal levels and controlling an excitation voltage supplied to a head transport motor to position a head device at a fine track position with respect to a recording track. (2) The head positioning control method according to claim (1), wherein the servo information is written alternately in a staggered manner at positions equidistant from the center of the recording track.