JPH01144280A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To obtain high-speed characteristic by counting the seek time of a carriage, comparing the seek time obtained from the above counting with a reference seek time, and supplying a signal to command the seek speed of a magnetic head and a signal to command the seek direction of the magnetic head relating to a compared result to a carriage driving circuit. CONSTITUTION:A counter means 21 counts the seek time of the magnetic head 3 at every seek direction. An output control means 23 compares the seek time of the magnetic head 3 with a reference seek operation time, and increases/ decreases output relating to the compared result, and supplies its output to the driving circuit 5 of the carriage 4 on which the magnetic head 3 is mounted, then, the seek operation of the magnetic head 3 is performed. Thereby, difference in the seek speed of the magnetic head 3 can be adjusted for every seek direction of the carriage 4. In such a way, it is possible to always obtain the high-speed characteristic in spite of the seek direction.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic disk device used in electronic computers, terminal equipment, and the like.

[Conventional technology]

5 and 6 are block diagrams and operational waveform diagrams of a conventional magnetic disk device disclosed in, for example, Japanese Patent Application Laid-Open No. 136973/1982. The magnetic disk 2 is driven by a spindle 2b to rotate at a constant speed. On the other hand, a magnetic disk 3 for writing and reading information is supported by a carriage 4 and driven by a carriage drive circuit 5 to be positioned on an arbitrary track of the magnetic disk 2. Position information is recorded in advance on the recording surface 2a of a specific magnetic disk 2 among the plurality of magnetic disks 2, and this is used as a servo disk, and the magnetic head corresponding to this servo disk is used as a servo head 3a. It is used exclusively for posting location information.

When the carriage 4 is driven by the carriage drive circuit 5 to perform a positioning operation (seek operation), a signal generated by the servo head 3a crossing the track of the servo disk is input to the position detection circuit 6, and position detection is performed. The position detection signal 101 is sent to the speed detection circuit 7.
Here, it is converted into a speed detection signal and fed back to the carriage drive circuit 5.

A position detection signal 101, which is the output of the position detection circuit 6, is also input to a pulse generator 11, converted into a pulse signal, and input as a position pulse signal 102 to a pulse counting circuit 12. The pulse counting circuit 12 counts the number of pulses of the pulse signal input from the pulse generator 11 and calculates the number of pulses to a predetermined value (4
The counting period signal 103 is output for only the time until the pulse becomes a pulse.

The clock counting circuit 13 receives the counting interval signal 103 from the pulse counting circuit 12 and a high-speed (for example, 4 MHz) reference clock pulse 106, and receives the counting interval signal 10.
3 counts the number of pulses of the reference clock pulse 106 during the on period, and the count value signal 104 (A) is the counted value.
and a pulse number setting value signal 105 (B) set based on the reference seek speed of the carriage 4 are input to the comparison circuit 14 . The comparison circuit 14 outputs an output signal to the output terminal 14a when the signal (A)>(B), and to the output terminal 14b when the signal (A)<(B).

The output terminals 14a and 14b are connected to one input terminal of each of the AND circuits 15 and 16, while the other input terminals receive an inverted signal of the counting interval signal 103, which is the output signal of the pulse counting circuit 12. πF is given, and the output signals of AND circuits 15 and 16 are given to a counting circuit 17.

When the counting circuit 17 receives an output signal from the AND circuit 15 or 16, it increases or decreases the preset value by, for example, a numerical value of 1, and converts the output signal into a D/A converter (digital/analog converter). A signal that is applied to the carriage drive circuit 18 and converted into an analog signal is applied to the carriage drive circuit 5.

The operation of this magnetic disk device will be explained with reference to FIGS. 5 and 6. A signal input to the servo head 3a by the seek operation of the carriage 4 is transmitted to the position detection circuit 6.
The position detection signal 101 is input to the pulse generator 11. Then, the pulse generator it generates a pulse signal at the positioned point and provides a position pulse signal 102 to the pulse counting circuit 12. When the pulse counting circuit 12 is given this position pulse signal 102,
For example, four pulses are counted, and a counting interval signal 103 that turns on the signal only during the counting interval is given to the clock counting circuit 13. The clock counting circuit 13 is supplied with the counting interval signal 103 and the reference clock pulse 106, counts the number of pulses of the reference clock pulse 106 in the interval in which the counting interval 103 is on, and uses it as the counting signal 104.
(A) is provided to the comparator circuit 14.

The comparison circuit 14 compares the number of pulses of the count signal 104 (A) counted by the clock counting circuit 13 with the pulse number setting value signal 105 (B) that is preset according to the reference seek speed of the carriage 4, An output signal is given to the counting circuit 17 via the AND circuit 15 when A)-(B) is positive, and via the AND circuit 16 when (A)-(B) is negative. Since the other input terminals of the AND circuits 15 and 16 are supplied with the inverted signal 103 of the counting period signal 103 from the pulse counting circuit 12, the counting circuit 17 receives a predetermined number of position pulse signals 102 from the pulse counting circuit 12. An output signal from the comparator circuit 14 is provided at the time when pulse counting is completed. Therefore, the counting circuit 17 starts the counting operation from the time when the output of the section count signal 103 becomes O.

If the comparison value in the comparison circuit 14 is A>B, this means that the seek speed of the carriage 4 is slower than the reference seek speed. Therefore, since it is necessary to increase the seek speed of the carriage 4, the counting circuit 17 is connected to the output terminal 1 of the comparator circuit 14.
When a signal is given from 4a, it outputs a value to which a predetermined value is added.

This output signal is converted into analog by the D/^ converter 18 and inputted to the carriage drive circuit 5, so that the seek speed of the carriage 4 is increased.

The seek operation of the carriage 4, which has become faster in this way, is given again to the pulse counting circuit 12 as a position pulse signal 102 by the position detection circuit 6 and pulse generator 11, and is converted into a counting interval signal 103, which is then sent to the clock counting circuit 12.
3, but the pulse interval of this count zone open signal 103 is shortened by the increase in the seek speed of the carriage 4. Therefore, the number of pulses of the count signal 104 counted by the clock counting circuit 13 becomes a value smaller than (A), that is, (8-α).

The comparison circuit 14 is given the count value signal 10 (8-α) from the clock counting circuit 13 and the pulse number setting value signal 105 (B), compares both signals, and finds that (A-α)>(B). If so, repeat the above operation and get (A-α)=(B)
Continue until. When (A-α)=(B), the seek speed of the carriage 4 matches the reference seek speed, and the carriage 4 is set to that seek speed.

Also, when (A-α)<(B), the above-described operation is repeated and the carriage 4 is set to that seek speed.

[Problem that the invention seeks to solve]

In the conventional magnetic disk drive described above, the carriage for positioning the magnetic head moves toward the inner or outer circumference of the magnetic disk, but the arm to which the magnetic head is mounted has a control board that transmits the input/output information of the magnetic head. A flexible printed card is placed along the magnetic head, and its base is curved, so the reaction force acting on the curved part of the flexible printed card is applied to the arm on which the magnetic head is attached, causing magnetic There is a difference in moving speed when the head moves toward the inner circumference of the magnetic disk and when it moves toward the outer circumference. Conventional magnetic disk drives cannot adjust the time difference, and there is a problem in that if the magnetic head is caused to perform seek operations in different directions, high speed performance cannot be achieved in either direction.

In view of the above-mentioned problems, the present invention is capable of correcting the seek time due to the difference in the seek direction of the carriage, and provides a magnetic head with a
An object of the present invention is to provide a magnetic disk device that can always achieve high speed regardless of the seek direction.

[Means for solving problems]

The magnetic disk device according to the present invention includes a measuring means for measuring the seek time of the carriage, and a seek time of the magnetic head, which compares the seek time obtained by the measuring means with a reference seek time, and determines the seek speed of the magnetic head in relation to the comparison result. and an output control means for providing a signal for commanding the magnetic head and a signal for commanding the seek direction of the magnetic head to the carriage drive circuit.

[Effect]

The measuring means measures the seek time of the magnetic head in each seek direction. The output control means compares the seek time of the magnetic head with a reference seek operation time, increases or decreases the output in relation to the comparison result, applies the output to the drive circuit of the carriage to which the magnetic head is attached, and controls the magnetic head. Make the head seek operation.

As a result, for each seek direction of the carriage,
The difference in seek speed of the magnetic heads is adjusted.

〔Example〕

The present invention will be described in detail below with reference to drawings showing embodiments thereof.

FIG. 1 is a block diagram of a magnetic disk device according to the present invention. A plurality of magnetic disks 2 are driven by a spindle 2b to rotate at a constant speed, and information is written on the disks,
A carriage 4 to which a magnetic head 3 for reading is attached is driven by a carriage 11 circuit 5 to seek onto an arbitrary track on the magnetic disk 2.

Position information is recorded in advance on the recording surface 2a of a specific magnetic disk 2 among the plurality of magnetic disks 2, and it is used as a servo disk, and the magnetic head corresponding to this servo disk is used as a servo head 3a. It is used only for reading this position information. When the carriage 4 is driven by the carriage drive circuit 5 and performs a seek operation,
The servo head 3a outputs a signal across the tracks of the servo disk, and the signal is given to the position detection circuit 6.

The position detection signal 101 of the position detection circuit 6 is transmitted to the speed detection circuit 7.
and the pulse generator 11.

The speed detection signal outputted by the speed detection circuit 7 is sent to the adder circuit 24.
is fed back to the carriage drive circuit 5. Further, the pulse signal 102 of the pulse generator
is applied to a counter 21 that counts trunk passing pulses. Counter 21 provides signals to and receives signals from microprocessor 23. Furthermore, the microprocessor 23 provides a signal to a timer 22 that measures the seek time of the carriage 4, and also obtains a signal from the timer 22 that measures the seek time. Then, the microprocessor 23 compares the seek time of the carriage 4, which is the output value of the timer 22, with a reference seek time preset in the microprocessor 23, and calculates a correction amount for adjusting the seek time based on the time difference. It is applied to the A converter 18. The output converted into analog by this D/A converter 18 is given to an adder circuit 24. The microprocessor 23 also provides a seek direction command signal 205 to the carriage drive circuit 5. The output of the adder circuit 24 is given to the carriage drive circuit 5. Furthermore, the microprocessor 23 is made to store the control contents of the flowcharts shown in FIGS. 2 and 3, and as shown in FIG. 4, the vertical axis represents the target speed and the horizontal axis represents the remaining number of cylinders ZPLS. A target speed curve S is stored, and this target speed signal 204 is given to the adding circuit 24.

Next, the seek operation of the carriage of the magnetic disk device configured as described above will be explained. The plurality of magnetic disks 2 are driven by a spindle 2b and rotate at a constant speed. A magnetic head 3 supported by a carriage 4 for writing and reading information is driven by a carriage 4 driven by a carriage drive circuit 5, and seeks onto an arbitrary track of the magnetic disk 2. A magnetic head corresponding to a servo disk that has been previously recorded on a specific recording surface 2a of the plurality of magnetic disks 2 does not read position information as a servo head 3a. When the carriage 4 is driven by the carriage drive circuit 5 and starts a seek operation, the servo head 3a crosses the l/rack of the servo disk and gives the signal obtained to the position detection circuit 6, and the output of the position detection circuit 6 is used for speed detection. A speed detection signal which is applied to the circuit 7 and the pulse generator 11 and outputted by the speed detection circuit 7 is fed back to the carriage drive circuit 5 via the addition circuit 24 to cause the carriage 4 to perform a seek operation.

Then, the control operation of the microprocessor 23 is controlled in a second manner.
The operation of the magnetic disk device will be explained based on the flowchart of FIG. 3 and FIG. First, the magnetic disk 2 is sought to zero cylinder 0CYL (Sl).

Next, the flag DI indicating the seek direction of the carriage 4 is set to O.
(S2). Here, when DI=O, the seek operation is performed inward of the magnetic disk, and when DI=1, the seek operation is performed outward. Next, counter 21
(S3), and the count value of track passing pulses counted by the navigation counter 21 is set as TZC. After that, the seek time measurement timer 22 of the carriage 4 is operated (
S4). When the timer 22 operates, the timer 22 is initialized. If DI=O, inward seek command signal 2
04 to the carriage drive circuit (S5). The carriage drive circuit 5 to which the seek command signal 204 is applied controls the carriage 4 to seek toward the inner circumferential side of the magnetic disk 2 . Further, in the case of DI-1, a seek command signal 204 is given to the carriage drive circuit 5 to seek toward the outer circumference side. Next, the target number of cylinders to be sought, 5TEP, is set (S6).

Then, 5TEP is substituted for the remaining number of cylinders ZPLS (S7), and a target speed signal 203 corresponding to the remaining number of cylinders ZPLS is output (S8). The correction amount H (DI) is D
/A converter 18 (S9), where H(0)
is the seek operation correction amount in the inner direction, and H(1) is the seek operation correction amount in the outer direction. Then, the count value TZC of the counter 21 is input. Next, the remaining number of cylinders ZPL
Compare S and the count value TZC of track passing pulses (
Sll).

If 5TEP=TZC, it is determined that the seek operation has ended.

In step (Sll), in the case of 5TEP #TZC, the seek operation is continued and the value of 5TEP - TZC is substituted for the remaining number of cylinders ZPLS (S12). As a result, the difference between the target number of cylinders 5TEP and the number of passing cylinders TZC is substituted for the remaining number of cylinders ZPLS.
Always remembers information about the number of remaining cylinders. And the fourth
The target speed based on the target speed curve S shown in the figure is determined by the addition circuit 2.
4, the carriage drive circuit 5 is controlled so that the actual rotational speed obtained by the speed detection circuit 7 follows the sum of the target speed and the correction amount which is the output of the D/^ converter 18.

When the seek operation is completed, the timer 22 is stopped (S1
3) Obtain the measurement time TM at that time, and calculate this measurement time T
M is the seek time TM(DI) of the carriage 4 (5
14).

Next, compared with the gate opening T when seeking to the target position corresponding to the number of cylinders 5TEP, 515), TM(DI)≠M
In the case of T, please compare the size of TM (old) and MT516)
, if TM(DI)<MT, it is determined that the measured time TM(DI) is shorter than the seek time to the target position, and 1 is subtracted from the value of the seek correction amount H (old)< (S17).

On the other hand, in step (S16), TM(DI)>
If it is MT, it is determined that the measurement time TM (DI) is longer than the seek time to the target position, and the seek correction 1f ((D
1 is added to the value of I) (318). Note that the larger the value of H(DI), the shorter the seek time.

Thereafter, the seek direction flag DI is inverted (S19).

As a result, after the seek operation in the inner direction is completed, the seek operation in the outer direction is performed. Also step (
In S15), in the case of TM (old) - MT, the measured time TM (DI) and the seek time MT to the target position are compared in magnitude (520). Here, for example, the inward seek time TM (0) is the seek time MT to the target position.
, the seek time TM(1) in the outward direction becomes the seek time MT to the target position so that the seek direction is reversed.
Determine whether it is equal to or not. Here, if the seek time MT (DI) to the target position in the inner direction is equal to the seek time MT to the target position, the seek direction flag DI is inverted (S19). and seek time TM in the inward direction
(0), the control operations from steps (S3) to (520) are repeated until the outward seek time TM(1) becomes equal to the seek time MT to the target position.

Then, when the condition of TM(DI) = MT is satisfied in step (520), TM(0) = MT, TM(1
)=MT and ends the control operation. In this way, a correction amount suitable for each seek direction can be obtained as the correction amount H(DI). Note that this correction amount H(DI) is stored in a storage area (not shown) in the microprocessor 23, and each time a seek operation is performed, the correction amount H(DI) corresponding to the seek direction is sent to the D/A converter 18. will give.

Then, there is no difference in seek time in each seek direction of the carriage.

In this embodiment, the seek time correction amount is given to the D/A converter 18, but the microprocessor 23
Even if the correction amount is directly applied to the target speed output from the target speed, the desired effect can be obtained.

〔Effect of the invention〕

As detailed above, according to the present invention, the seek time of the carriage on which the magnetic head is attached is measured with a timer, and
An excellent magnetic disk device that has a simple structure because it is configured to adjust the seek time using an output control means, can seek the magnetic head to a predetermined position with high precision, and can always achieve high speed regardless of the seek direction. can be provided.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a magnetic disk device according to the present invention;
Figures 2 and 3 are flowcharts showing the control contents of the microprocessor, Figure 4 is a graph showing the relationship between the target speed and the number of remaining cylinders, Figure 5 is a block diagram of the magnetic disk device, and Figure 6 is its 5 is a timing chart of signal waveforms of each part. 2...Magnetic disk 3...Magnetic head 4...
Carriage 5... Carriage drive circuit 6... Position detection circuit 7... Speed detection circuit 11... Pulse generator 18... D/A converter 21... Counter 22... Timer 23...・Microprocessor In the figures, the same reference numerals indicate the same or equivalent parts. Agent Masu Oiwa Owara 2 Diagram 3

Claims (1)

[Claims] 1. A magnetic disk that detects a track on a magnetic disk and applies a signal related to the detected signal to a drive circuit of a carriage for moving a magnetic head to perform a seek operation of the magnetic head. In the apparatus, a measuring means for measuring the seek time of the magnetic head, a means for comparing the seek time measured by the measuring means with a preset reference seek time, and a measuring means for measuring the seek time of the magnetic head in relation to the comparison result. 1. A magnetic disk drive comprising: output control means for providing a signal for commanding a seek speed and a signal for commanding a seek direction of a magnetic head to a carriage drive circuit. 2. The magnetic disk device according to claim 1, wherein the signals given to the carriage drive circuit are set separately in the seek direction of the carriage.