JPS62273680A - Head position control system for disk memory device - Google Patents

Abstract

PURPOSE:To reduce the access time by writing the 1st and 2nd reference information into areas shifted to each other in the drive direction of a disk as servo information, and detecting an off-track value from a read signal so as to apply off-track correction. CONSTITUTION:The 1st reference information 10 and the 2nd reference information 20 are written in areas shifted to each other in the drive direction of a disk 1 as servo information. The off-track is detected from the read signal of the information 10, 20 by an off-track detection circuit 40 and at every time the value exceeds the allowable value, a control command is given from an off-track correction circuit to a head position operation circuit 30 to correct the off-track. When the off-track value is within a permissible value and a control command is given to the circuit 30 based on the information 20, a control end confirming circuit outputs an end signal representing the end of positioning control of the head 3. Then the head is surely positioned to a normal position on a prescribed track within one drive period of the disk 1.

Description

[Detailed description of the invention]

3. Detailed description of the invention

[Technical field to which the invention pertains]

The present invention relates to a method for controlling the positioning of a transducer head for reading and writing information with respect to a plurality of tracks set on an information recording medium disk that rotates at a constant speed in a disk storage device typified by a fixed disk device.

[Prior art and its problems]

As disk storage devices have progressed and their storage capacity has increased, hundreds of tracks or more have been set on the disk, and it has become necessary to narrow the distance between the tracks. Therefore, as a position control system for a head for reading and writing information to each track, a simple open-loop position control system is often insufficient in terms of accuracy, and a closed-loop position control system is becoming popular. Of course, such a position control method requires detection of the current position of the head, and for this reason it is advantageous to write reference information, so-called servo information, on the disk surface. Initially, an entire disk surface was allocated exclusively for this reference information, but this meant that a considerable portion of the valuable disk surface for recording information was allocated for reference information, so recently Nowadays, a so-called data surface navigation method has been adopted in which reference information is inserted and written into a part of the disk surface on which information is recorded. In such a position control method, the reference information occupies no more than a few percent of the disk surface, and the information record that the disk has! In a disk storage device that adopts this position control method, which requires almost no sacrifice of i performance, the vi position detects the current position of the head from reference information and performs closed-loop control of that position within the device. Therefore, the user of the device can use the gA position without being aware of this automatic control or that reference information is written on the disk surface. Therefore, the reference information or servo information is invisible to the user. The method of the present invention, which is called an embedded servo method in the sense that it does not exist, also relates to the position control method of the data surface servo method or the embedded servo method. Now, when a disk storage device is used in combination with a computer, it is always required that the access time to information in the disk storage device from the computer's perspective is extremely short. To position the head on the track where the information is to be stored when reading or writing the required information, the head operation motor, usually a stepping motor, is first repeatedly sent a pulsed signal. Move the head a distance according to the number of tracks, and place the head near the desired track! During this so-called seek operation, the position control is an open-loop control system, but then the head position is changed to closed-loop control, and while reading reference information, the head position is corrected and fixed on the normal position of the track. In addition to the time required for head position correction, there is also the time required for the previous inter-track movement, so there has been a tendency for shortening the access time to not be much of an issue in the past. However, the seek operation time of the head has been streamlined to a near limit through measures such as selecting the repetition interval of the pulsed signal given to the head operation motor so as to minimize the travel time. Therefore, in order to further reduce access time, it is important to shorten the closed loop control time for head position correction. Now, when correcting the head position, the amount of deviation of the head track from the normal position is detected from the signal read out from the reference information in the form of an off-track value, and a control command is given to the head operating motor to set this off-track value to zero. However, it is advantageous to issue this control command in the form of specifying the internal electrical angle or phase of the head operating motor. In other words, the head operating motor has a reference position in electrical angle corresponding to the normal position of the track, and there is a control system that includes a correction amount from this reference position according to the detected off-track value. 11 to the head operating motor, and if there is an accurate correspondence between the electrical angle of the head operating motor and the position of the head, one correction control will move the head to its normal position on the track. should be placed correctly. Of course, this prerequisite correspondence clearly exists, but there is also a small amount of frictional force that exists in the mechanical coupling system between the head operating motor and the head, and the proportional relationship between the electrical angle and mechanical angle of the head operating motor itself. Since some errors are introduced, the reproducibility in the correspondence between the electrical angle given to the head operating motor and the herad digit tends to be slightly distorted, and it also changes due to the influence of the ambient temperature and the device temperature. Therefore, in reality, it is common for correction control to be performed two or more times before the head is finally located at the correct position on the track. As mentioned above, this correction control is a closed-loop control, but if we consider its contents in more detail, we can see that the reference information is written only on a part of the disk, and the off-track value detected from the read signal. Since this is normally obtained only once per rotation of the disk, correction control based on this is necessarily intermittent or rose-drop control. In other words, the head position correction control is an intermittent or repeated rose-loop control synchronized with the rotation of the disk, and during the control time, this control is performed every one rotation period of the disk, for example, every 20 seconds. The minimum time required is multiplied by the number of repetitions, and this is a bottleneck in shortening the head correction control time. Of course, such a bottleneck does not exist in the dedicated surface servo method described above, in which reference information is written on the entire surface of the disk. The advantages of the servo system will be lost.

[Purpose of the invention]

The purpose of the present invention is to take advantage of the advantages of the data surface servo method or the embedded servo method head position control method, and to
The object of the present invention is to obtain a head position control method that can shorten the time for accessing information to a disk storage device by shortening the head position correction control time to the same extent as the dedicated surface servo method.

[Key points of the invention]

According to the system of the present invention, the object is to provide a head position operating means for manipulating the position of the head in a direction transverse to the tracks and holding it at a predetermined position, and a head position operating means for manipulating the position of the head in a direction transverse to the track and holding the head at a predetermined position, respectively, for a head position control system of a disk storage device. From the first and second reference information written in areas that are part of the disc and are shifted from each other in the rotational direction of the disk, and the signals sequentially read out from the reference information via the head, it is possible to determine the position of the head from the normal position with respect to the track. An off-track value detection means for detecting an off-track value indicating a deviation, and a normal value for tracking the head based on the off-track value whenever the off-track value exceeds an allowable limit! off-track correction control means for issuing a control command to the head position operation means to perform a correction operation;
and a control completion confirming means that issues a completion signal indicating that the head positioning control is completed, when the off-track value detected by the off-track value detecting means from the first reference information read signal is within a permissible limit; and This is achieved by causing the control completion determining means to issue a completion signal at any time when a control command is issued from the off-track correction control means to the head position operating means based on the second reference information. Therefore, according to the present invention, the head position correction control is substantially completed at the earliest when the correction control based on the first reference information is completed, and at the latest when the correction control ffl operation based on the second reference information is completed, and the control is completed. Since a completion signal indicating the completion of the head position control method is emitted from the determining means, the time required for correction control is reduced to several minutes of one rotation period of the disk, which is approximately 1/lo of the correction control time according to the conventional technology. can be shortened to Practical advantageous embodiments for implementing the method of the present invention are described in the following section.

[Embodiments of the invention]

Hereinafter, embodiments of the system of the present invention will be described in detail with reference to the drawings. FIG. 1 is a circuit configuration diagram showing various means used to implement the method of the present invention together with related parts of a disk storage device. In FIG. A computer using ? is shown schematically at 200. At the top left of the diagram is a disk storage? A side view of the main part of a fixed disk device as t W is schematically shown, and two disks for information storage are designated by l. On the upper side of the disk 1, several hundred information storage tracks 2 are set, as shown schematically in the plan view of the disk surface, and as shown by hatching in the figure, the information storage tracks 2 are An area is set in a part of the group in the circumferential direction to write the first reference information IO and the second reference information 20 for the method of the present invention. In the present invention, it is advantageous to use two pieces of such reference information as shown in the figure, but it is also possible to use three or more pieces of reference information, which is not a very large number. It is better to use multiple reference information. Four heads are used for reading and writing track information and reference information, one for each disk surface, each of which is moved forward and backward in the direction of arrow P in the figure via a flexible arm 3a. Commonly supported by 4. The carriage 4 is movably moved in the direction P by a base 5 of the device via rollers or balls 4a, and a capstan 3 is rotated in the direction of the arrow Q in the figure.
A gold r with the central part fixed at one place on 1a, wrapped once around it, and fixed at both ends to the carriage.
The capstan 31 is connected via a band 4b made of a thin plate.
It is mechanically tightly coupled to a. Capstan 31a
is directly connected to the rotor 31 of the head operation motor as the head position operation means 30 shown on the right side.
By rotating the head operating motor by a predetermined angle, the carriage 4 and therefore the head 3 can be moved to a desired position in the P direction. The disk 1 is fixed to a spindle shaft 6a of a so-called spindle motor 6 and driven at a substantially constant speed by the motor, and a pulse generator 6b that emits a so-called index pulse IDX in synchronization with the rotation is built into the spindle motor 6. It is assumed that Since the reference information mentioned above is written in synchronization with this index pulse, in order to implement the method of the present invention, the index pulse may be generated from the read signal of the reference information. The illustrated head operating motor is a two-phase spindle motor, with two phase coils 32a and 32b connected to A and B.
Phase currents 1a are provided for both phases and have phases of 90 degrees from each other from the drive circuit 33 shown on the right side. ! b. Is the drive circuit 33 controlled? The control given to this drive circuit 33 may be a known circuit that receives one command CS and outputs, for example, a PWM output current having a duty ratio according to the signal value as the phase current.
In this case, I7 signal cs is a signal with a multi-bit configuration,
It consists of one pin for specifying the phase, one bit for specifying the positive/negative direction of the phase current, and multiple bits for specifying the phase current value. Each detection coil 3 when the head 3 is a magnetic head
b is a known read/write circuit 7 shown in the center of the figure.
The read/write circuit 7 receives the read/write command RW and the head selection signal H5 and outputs the read output R of the coil 3b of the head designated by the head selection signal Its in accordance with the determination by the read/write command. Or read directly to write input W. The off-track value detection means 40 shown below is a microcomputer means 7 incorporated in the disk storage device in this embodiment.
0 is an electronic circuit configured separately from the above-mentioned read/write circuit 7, which receives the reference information read signal from the read output R of the read/write circuit 7 via the attached switching circuit 40a and the demodulation circuit 8, and receives the off-track signal. Emit the value Ov. The demodulation circuit 8 may also be used for calculation [read data R1 given to 1200] when the switching circuit 40a takes a switching position opposite to that shown. Off-track value detection means 40 is shown as a block in the figure.
A circuit that can detect the amount of deviation from the normal position of the head relative to the track as an off-track value from the reference information readout signal (for example, the applicant's earlier application, Japanese Patent Application No. 1983)
0-197410) is sufficient, but Figure 2~
The outline will be explained below with reference to FIG. FIG. 3 is an expanded view showing the track 2 on the disk 1 shown in FIG. 2 and one of the reference information 10.20, in which the reference information 10a and 10b are shown. is written centering on a position indicated by a point ui gland between adjacent tracks 2. Reference information in this example tg
lOa. 10b is simple on/off information that is repeated, for example, about 100 times, as shown in the i11 pattern,
In addition, the data are written alternately and staggered in the rotational direction R of the disk. If the head 3 is deviated from the center position indicated by a thin solid line in the diagram of track 2 by 6 as shown, both of these reference information 10a, 10b
The readout signals R3a and R5b are obtained temporally shifted from each other, as shown in the fourth peak, and their peak values are different from each other. As shown in the figure), these readout signals R3a and RSb are read in synchronization with the index pulse IDX shown in the figure ial, and their waveforms are pulse-like repeating waveforms that oscillate in positive and negative directions. . The off-track value detection means 40 uses the index pulse I
It has a built-in means for generating a threshold ill signal TH in synchronization with OX, and the threshold signal TH generated thereby has a symmetrical triangular waveform with a middle height as shown in FIG. 4Cb). Read signal received by off-track value detection means 4o! 1
5,1. R5b is internally compared with the threshold signal TH, and the portion of the pulses included in the read signals R5a and R5b that exceeds the threshold signal Tll is converted into a train of count pulses CPa and CPb. The off-track value detection means 40 detects the count pulses CPa and CPb.
The difference na - nb between these two pulse numbers is equal to the off-track value O
It is output from the off-track value detection means as V (negative value in this case). Of course, the reference information 10.20 and the off-track value detection means 40 may have other configurations than this, and in some cases, part or all of the off-track value detection means 40 may be incorporated into the micro combinator means 70. You may also do so. Returning to FIG. 1, the off-track correction control means 50 receiving the above-mentioned off-track value Ov is, in this embodiment, software incorporated in the micro combinator means 70, and the off-track value Ov is input to the off-track correction control means 50. Receive via port door 1. In addition, the microcomputer means 70 inputs the above-mentioned index pulse IDX to the input port door 1.
In response to this, signals such as a read/write command RW to the read/write circuit 7 and a head selection signal H5 are issued via the output port door 2. Also, the microcomputer means 7
0 is RAM 73 as its internal storage means as usual.
In the ij[RAM 73, a correction value table area 51, 52 for storing a table of correction values in cooperation with the off-track correction control means 50 is set. The off-track correction control means 50 is the off-track value detection means 40
Off-track value Ov received from and this correction value table area 5
Multi-bit control command CS from the correction value read from 1
is created and applied to the drive circuit 33 of the head position operating means 30. In this embodiment, the microcomputer means 70 further includes control completion determination means 60 in the form of software, which cooperates with the off-track correction control means 50 to issue a completion signal SC. Now that the explanation of the various means constituting the system of the present invention has been almost completed, the overall operation thereof will be explained with reference to FIG. 5. FIG. 5 is a flowchart showing the contents of the above-mentioned off-track correction control means 50 and control completion determination means 60 in terms of software, and the flow of the operations of both means is shown surrounded by a chain line. Since the flow shown in the cough diagram is during hemad position control, the read/write circuit 7 selects the head specified in advance by the head selection signal H5, and is placed in a reading state by the read/write command RW. It is assumed that the switching circuit 40a is placed at the illustrated switching position where the readout signal from the read/write circuit 7 is transmitted to the off-track value detection means 40 via the demodulation circuit 8 at the time when the seek signal SK is issued. It is also assumed that the head position operating means 30 receives a predetermined number of pulse signals from the micro combinator means 70 during the seek operation of the head, and positions the head near the desired track using the open-loop control described above. FIG. 5 shows the flow of position correction control in the aforementioned closed-loop control system, which is performed subsequent to the head seek operation. In the first step Sl shown in the figure, the system waits for the index pulse +[1χ arriving from the manual port door 1. In step S2 after the index pulse arrives, 1 is set in variable 1 representing the reference information number. As shown in FIG. 1, the upper index pulse IDX is also applied to the off-track value detection means 40, which detects the reference information coming from the read/write circuit 7 following this index pulse. After performing the above-mentioned detection operation based on the readout signal, the next step S3 shown in FIG. At the same time as the arrival, the process moves to the next step S4 and the off-track value Ov
Of course, this off-track value Ov is a value detected based on the first reference information 10. Step S5 is an operation step of the control completion confirmation means 60, and the read off-track value Ov is the permissible limit OVM.
First, it is determined whether or not it is within the range. As mentioned above, in many cases this condition is not met from the beginning, so the flow returns to step S6, which is the operating step of the off-track correction control means 50. These steps are for switching the manner in which the correction value is determined depending on whether the off-track value Ov is detected based on the first reference information or the second reference information. Initially, in the former case, the variable l is 1, so the flow is step S7
Move to. This step S7 is a step of reading out the correction value CVI corresponding to the off-track value Ov based on the first reference information from the above-mentioned correction value table area 51.The meaning of this correction value will be explained with reference to FIG. explain. FIG. 6 (arrow) shows the correlation between the electrical angle of the head operating motor on the horizontal axis as the head position operating means 30 and the position of the head 3 on the vertical axis. should be perfectly proportional to . However, in reality, there is a complicated correlation as shown by curve B, so that the head deviates from its original position by an off-track amount indicated by ΔX with respect to a certain electrical angle θ. This off-track amount ΔX is the off-track value O
It is detected as v. Meanwhile, bl is an electrical angle diagram of the head operation motor, and the reference positions of the composite vectors corresponding to various combinations of the two positive and negative phase currents 1a and Ib are indicated by 1 to 16. Assume that among these reference positions 1, odd numbers 1.3 to 15 correspond to positions where reference information is written, and even numbers 2, 4 to 16 correspond to track positions. Assuming that it is near the center of the track corresponding to position number 2, in order to correct the aforementioned off-track amount ΔX, the electrical angle is
It is necessary to shift by Δθ shown in al, and this position is shown by a chain line in t) of the same figure. In other words, in the track corresponding to reference position 1 number 2, the correction value is the phase current! b has to be increased by Δlb shown in the figure, and this is the above-mentioned correction value Cvl. The correction value table area 51 stores the correction value Cv1 as a table using the off-track value Ov as a variable, and the above-mentioned step s7 is the step of reading out this stored value. In step S9 of the off-track correction control means 50, the positive and negative signs of the values of the phase currents Ia and Ib to be applied to the head operation motors are calculated based on the correction value CVI obtained in this way, and the control command CS is calculated. The signal is applied to the drive circuit 33 of the head position operating means 30 as a signal. The next step 310 is to determine whether the variable i has reached its maximum value m. If the number of reference information is 2, this maximum value m is also 2. However, at first, the value of the variable i is still 1, so by moving to step Sll below and adding 1 to the variable l, after specifying that the correction control based on the second reference information 20 is to be entered. Flow step S
Return to 3. 2 from step S3 when the number of reference information is 2
The second flow is a correction control operation based on the second reference information 20, in which the off-track value Ov detected based on the second reference information 20 is read in step S4 as before, and in step S5. It is determined whether this value is within the allowable limit, and as long as it is not, the process moves to the next step S6, but since the value of the variable l is 2 this time, the flow moves to step S8. The reading of the correction value CV2 in step S8 may most easily be done by reading out the correction value data from the correction value table area 51 in the same way as in step S7, but it is possible to read out the correction value CV2 from the current off-track value and the previous off-track value. It is preferable to read the correction value data from the correction value table area 52 using the difference from the current off-track value as a variable.Rather than simply determining the correction value using the current off-track value as a variable, it is preferable to read out the correction value data using the difference from the previous off-track value as a variable. This is because determining a correction value can provide a more reasonable correction value for correctly positioning the head at a normal position on the track. After step S8, the control command C5 is issued to the drive circuit 33 in step S9 as before, but in the next step S9
This time, the determination result is correct, so the flow skips the loop and moves to step S12. In this step 512, a short time limit TL for operating the head is set based on the control command given to the head position operating means 30 in the previous step S9. Since this operation time is approximately directly proportional to the scraping distance and thus the detected off-track value, it is desirable to select a short time period so that it is directly proportional to the off-track value.The following step 513 is a waiting step, Wait for the set time limit TL to elapse. At step 514 after the time limit has elapsed, a seek completion signal SC indicating that the head seek operation including the closed loop position control period has been completed is issued as a completion signal, and the entire flow ends. The operation of the control completion confirming means 60 is as described above in step 510 and step 51.
In addition to steps 2 to 514, the process includes the previous step S5 as shown in FIG. After making a call, the entire operation flow is immediately completed. Now that the explanation of the operations of the various means constituting the present invention has been completed, an example of the pattern of head position control accompanying the above operations will be explained next with reference to FIG. The horizontal axis of the figure is all taken as time t, and one rotation period T of the disk is shown at the top. As can be seen from the figure, this rotation period T is an enlarged view of the first rotation period after the generation of the index pulse IDX shown at +8) in the same figure. 1) is a well-known mask signal MSK for disk storage devices, which is generated, for example, from a mask signal generation circuit 9 receiving an index pulse IDX shown at the bottom of FIG. The mask signal generation circuit 9 may be a known H-like circuit that generates a mask signal with a pulse width corresponding to the reading time of the reference information after generation of the index pulse IDX, but in this embodiment, the reference information The mask signals indicated by MSKI and FISK2 are generated twice in response to the fact that two of them are provided, and in synchronization with the termination of the mask signal MSKL, the auxiliary index pulse IDXa shown in FIG. This auxiliary index pulse is an index pulse that is issued from a normal embedded reference information type disk storage device to the user, that is, the computer 200, and notifies the timing of starting writing or reading.
,! The pulse width of l5K2 is taken to be equal to the time width required for reading the first reference information 10 and the second reference information 20, which corresponds to the writing time, and this is shown as the servo reading time TS in FIG. . FIG. 7+dl shows an example of the pattern of actual position control of the head, with the head movement I shown by a solid line, and the normal position of the target track is shown by NP. The off-track value detected by the off-track value detecting means 40 as a result of reading the first reference information 10 in synchronization with the Intex pulse is indicated by OTI, and the progress of position control based on this is indicated by the OTI. To continue, do i a
It is indicated by IIMI. In this example, head movement HM
As can be seen from the progress of I, position control based only on the first reference information 10 fails to bring the head to the normal position MP. Therefore, it is necessary to perform position control again based on the second reference information 20, and for this purpose, the second reference information 20 is is read. The off-track value detected after the second servo reading time TS is OT2, and as a result of position control being performed again based on this, the head is brought back to the track after the above-mentioned time limit TL has elapsed following the progress shown by the solid line. is statically fixed at the normal position NP. Of course, at the same time, the aforementioned seek completion signal SC is issued as shown in (0) of the same figure. As shown in FIG. 1, a weighing machine 200 as a user
receives this seek completion signal SC and the aforementioned auxiliary index pulse l0Xa, and writes information to or from the disk storage device 100 in synchronization with the auxiliary index pulse rDXa on the condition that the seek completion signal SC exists. Just start reading. As can be seen from the example shown in FIG. 7 Td+, the intermediate time 1 is selected to be a position control time that is slightly shorter than the time until the head position control based on one control command SC is completely completed. It is reasonable to shorten the overall length. Experience has shown that it is desirable to choose the intermediate time TI to be equal to or slightly shorter than the positioning time of the head based on the control commands; when so chosen, the head has two references as in this example. By performing the control twice based on the information, it is possible to almost completely stabilize the track at the normal position. Now, in this way, the intermediate time ↑ is convenient for position control! If , the first reference information lO and the second reference information 20 are placed apart from each other in the rotational direction R of the disk, as shown in FIG. As shown in the figure, the information recording areas include an information area DA that does not include a plurality of pieces of reference information;
Although it is divided into the auxiliary information area DAa sandwiched between the reference information, this does not cause any particular trouble in reading and writing information.As mentioned above, the auxiliary index pulse is immediately generated after reading the first reference information. Since IDXa is generated, it is only necessary to read and write information in synchronization with it, but not to read or write while mask signal MSK2 is present. Also 1
As is well known, the track is divided into a plurality of sectors, for example, 32 sectors, so in reality, the auxiliary information area D
It is convenient to select the width of Aa to be an integral multiple of the length of one sector in order to make effective use of the recording capacity of the disk.According to experience, it is convenient to select the intermediate time TI to be convenient for position control. The size of the auxiliary information area DAa is 3 to 4.
It is best to choose the sector length. FIG. 7 (fl shows the state of the head movement 11M in the conventional head position control method in comparison with the example fdl in the same figure according to the method of the present invention, and corresponds to the flow of position control shown in FIG. Each operation step in FIG. 8 is indicated by the same reference numeral and the same content as the operation step in the case of the present invention, and as shown in the figure, the control command C8 in step S9
Each time , the flow of operation returns to the step of waiting for the index pulse IDX in step Sl, and only when it is determined in step S5 that the off-track value is within the allowable limit, the process jumps to step 514 to issue the seek completion signal SC. emits. Therefore, after the position control is performed in the first rotation period T, there is no opportunity to perform position control again until the next rotation period, and the off-track value O after the first position control is at the second rotation period ゛r. It is detected only in synchronization with one Kero index pulse χ, and if necessary, the collar opening must be repeated repeatedly.Therefore, in the case of the conventional technology, at least one rotation cycle is required for head position control. Normally, position control is required about two times, so about two rotation cycles are required, so the seek completion signal SC is issued at the beginning of the third rotation cycle, as shown in Tgl in the same figure. . As can be seen from the above description, in the case of the position control method according to the present invention, the head position control can be completed within a fraction of the period of one rotation. As can be easily understood, the head position control method for a disk storage device according to the present invention can be implemented in various ways B different from those in the above-described embodiments. For example, the first reference information and the second In many cases, it is desirable to write the reference information on the same disk surface as in the embodiment, but since there are multiple disk surfaces in a disk storage device, the reference information may be distributed or dispersed on different disk surfaces. As described above, there is no problem in arranging and writing the reference information, and the total number of reference information is not limited to two, but may be provided in a larger number as long as it is not too large. Effects of the Invention In the head position control n method of a disk storage device according to the present invention, first reference information and second reference information are written as so-called servo information written within the disk surface for information recording, and These are written in areas shifted from each other in the rotational direction of the disk, and the off-track value detection means uses the read signal of these reference information to output the off-track (direct) and calculate the off-track (
Each time the off-track value exceeds the allowable limit, the off-track correction control means issues a control command to the head position operating means to correct the off-track value, and when the off-track value is within the allowable limit by the control completion I determining means, Even when a control command is issued to the head position operating means based on the second reference information, a completion signal indicating the completion of head positioning control is issued, so that the head positioning control is reliably performed within one rotation period of the disk. The head can be positioned at a regular position on a predetermined track and kept stationary, reducing the closed-loop control time of the head to approximately 1710 degrees compared to the conventional method in which an off-track value can be obtained only once per period of one rotation of the disk. hand,
The time required to access information to the disk storage device can be reduced. Since multiple pieces of reference information are written on the disk surface, it may seem at first glance that the disk surface for recording information is reduced by that much, but the area required for reference information can be seen from the entire disk surface. In practice, it is possible to use the reference information area within the so-called gap, which has traditionally been provided within the track, and even if this is inappropriate, the disk rotation can be reduced slightly. You can create that extra margin just by lowering it. Further, as described above, the information recording area between the reference information is not completely wasted, and can be effectively used for information recording. The usability of the disk storage device from an external user's perspective is virtually the same as that of conventional devices, provided that the seek completion signal is issued as the completion signal as described above. It is only necessary to write or read information in synchronization with an auxiliary index pulse, which is an index pulse seen from the outside. In addition, each of the means constituting the system of the present invention may be essentially the same as conventionally used means, so that the above-mentioned remarkable effects can be obtained without complicating the structure.

[Brief explanation of drawings]

1 to 7 are for explaining the present invention, and FIG. 1 is a circuit configuration diagram showing the constituent means of the head position control system for a disk storage device according to the present invention together with a related computer, and FIG. The figure is a layout diagram showing an example of the arrangement of the first reference information and the second reference information on the disk surface, and FIG.
FIG. 4 is a layout diagram showing an example of one of the reference information and the second reference information together with the track, and FIG. FIG. 4 is a flowchart of the operation in the off-track correction control means and control completion confirmation means for explaining an example of the overall operation of the method of the present invention, and FIG. 6 is a stripe diagram illustrating the amount of off-track and correction. FIG. 7 is an electrical angle diagram of the head position operating means for explaining the values, and FIG. 7 is a waveform diagram and a diagram illustrating the pattern of head movement together with related signals when the method of the present invention is implemented. FIG. 8 is a frozen diagram showing the operation for head position control according to the conventional method. In FIG. mask signal generation circuit,
lO: first reference information, 10a, 10b: reference information,
20: second reference information, 30: head position operating means, 3
1: Rotor of head operation motor, 32a, 32b: Phase coil of head operation motor, 33: Drive circuit of head position operation means, 40: Off-track value detection means, 40a
: disconnection circuit for off-track value detection means, 50: off-track correction control means, 51, 52: correction value table area that cooperates with the off-track correction control means, 60: control completion confirmation means, 70: microcomputer means, 73: RAM in microcomputer means, 100: Disk storage device, 200: Computer, C1 control command, CV, CV
l, CV2: correction value, information recording area on the disk, DAa: auxiliary recording area on the disk,
1st, IIMI, 8M2: Head 1 hyperactivity amount, Hl head selection signal, Ia, Ib: Phase current of head operation motor, IDX: Index pulse, IDXa:
hi auxiliary index pulse, l (・1 to m): variable indicating reference information number, MSK, MSKI, FISK2 j mask signal, NP:) normal position of rank, OT, OTI,
OT27 off-track amount, Ov: off-track value, OV
M: Permissible limit, P: Head operation direction, Q: Head operation motor rotation direction, R: Disk rotation direction, RD: Read data, B: Read/write command, seek completion signal as SC2 completion signal, S2 ~S4. S6~S9.5
11: Operation step as off-track correction control means, S5. S12 to S14: Operation steps as control completion confirmation means, T: Rotation period of disk, ↑! : intermediate time between reference information, TL: time limit, TS: servo reading time,
t: time, -0: written data ΔX, δ: off-track amount, Δθ: electrical angle to be corrected. Figure 3 Figure 7

Claims (1)

[Scope of Claims] 1) A positioning control system for a transducer head for reading and writing information with respect to a plurality of tracks set on an information recording medium disk rotated at a constant speed of a disk storage device, the method comprising: controlling the position of the head; a head position operating means for operating in a direction across the track and holding it in a predetermined position, and first and second references written in respective areas that are part of the circumferential direction of the disk and are offset from each other in the rotational direction of the disk; off-track value detection means for detecting an off-track value indicating a deviation from the normal position of the head relative to the track from a signal read out from the information and the reference information sequentially through the head; Off-track correction control means that issues a control command to the head position operating means to correct the head to the normal position of the track based on the off-track value, and control completion confirmation that issues a completion signal indicating that the head positioning control is completed. means, when the off-track value detected by the off-track value detecting means from the read signal of the first reference information is within the permissible limit and based on the second reference information, the control command is sent from the off-track correction control means to the head. 1. A head position control method for a disk storage device, characterized in that a completion signal is issued from a control completion determining means at any time when a completion signal is issued to a position operation means. 2) A head position control method for a disk storage device according to claim 1, wherein the first reference information and the second reference information are written on the same disk surface. 3) In the method described in claim 1, the first reference information and the second reference information are mutually separated at intervals corresponding to a short time period that is equal to or slightly shorter than the head position operation time by the head position operation means. A head position control method for a disk storage device characterized in that data is written on the disk at intervals. 4) A disk storage device according to claim 3, wherein tracks on the disk within a mutual interval range of the first reference information and the second reference information are used for information recording. head position control method. 5) A head of a disk storage device according to the method described in claim 4, characterized in that the mutual interval between the first reference information and the second reference information is selected to be a multiple of the information recording sector length. Position control method. 6) In the method described in claim 1, the control completion confirmation means, after the control command is issued from the off-track correction control means to the head position operation means based on the second reference information, A head position control method for a disk storage device, characterized in that a completion signal is emitted after a short period of time corresponding to the head position operation time of a head position operation means based on the head position control means. 7) The method according to claim 6, characterized in that the short time is selected to be approximately proportional to the off-track value detected by the off-track correction control means based on the second reference information. Head position control method for disk storage devices. 8) In the method described in claim 1, the off-track value detection operation by the off-track value detection means based on the first reference information and the subsequent operation of generating a control command by the off-track correction control means are performed in accordance with the rotation of the disk. A head position control method for a disk storage device characterized in that head position control is performed in synchronization with a synchronized index pulse. 9) In the method described in claim 8, the first reference information and the second reference information are embedded servo information, and another index pulse for instructing the start timing of reading and writing information to the track is embedded in the disk. A head position control method for a disk storage device, characterized in that the head position is emitted from the storage device. 10) A disk according to claim 1 or 9, characterized in that the control completion determining means issues a completion signal as another index pulse instructing the start timing of reading and writing information to the track. Head position control method for storage devices. 11) In the method described in claim 1, the off-track correction control means comprises the off-track value detected by the off-track value detection means based on the first reference information and the off-track value versus necessary correction value table. 1. A head position control method for a disk storage device, characterized in that a correction value is calculated by the above, and a control command is issued based on the correction value. 12) In the method described in claim 11, the off-track correction control means calculates the correction value based on the off-track value detected by the off-track value detection means based on the second reference information and the correction value table. 1. A head position control method for a disk storage device, characterized in that a control command is issued based on the correction value. 13) In the method described in claim 11, the off-track correction control means performs a correction based on the off-track value detected by the off-track value detection means based on the second reference information and another correction value table. A head position control method for a disk storage device, characterized in that a correction value is calculated and a control command is issued based on the correction value.