JPH04176078A - Magnetic disk apparatus - Google Patents

Abstract

PURPOSE:To make it possible to access a plurality of disks with one magnetic head by arranging a rotary head wherein a plurality of magnetic heads are arranged on the circumference at the center of a plurality of rotating disks. CONSTITUTION:Three disks 1 are arranged so that the centers of the rotations are located at the vertexes of a regular triangle. The disks are rotated clockwise at a constant speed. A rotary head 2 is arranged so that the center of rotation is located at the center of gravity of the regular triangle. The head is rotated clockwise at a constant speed. Six magnetic head 3 are arranged at the outer surface of the rotary head 2 at an equal interval. The phase of the rotary head 2 is controlled with a phase controlling device 13. Of the locus of each magnetic head 3 when the head 3 passes on the disk 1, the part when the magnetic head 3 is directed toward the outside from the inside of the disk 1 is made to be a recording track 6. Then, the recording track is formed in the radial pattern on the disk 1. Thus, a plurality of the disks can be accessed with one magnetic head at the same time, the track length is equal and the reliability of each track can be made constant.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the principle, structure, recording method, and positioning method of a storage device using a magnetic disk.

[Conventional technology]

In conventional magnetic disk drives, one magnetic head accesses only one disk disk.

The recording tracks on the disk are formed concentrically,
The outer circumference has a longer track length than the inner circumference. Positioning to each track is performed by reciprocating movement of the magnetic head by an actuator.6 [Problem to be Solved by the Invention] In the above-mentioned conventional technology, one magnetic head can only access one disk disk. As the number of disks increased, the device became larger.

Furthermore, since the recording tracks on the disk are concentric and the outer tracks are longer than the inner tracks, the reliability of the inner tracks is lower than that of the outer tracks.

One object of the present invention is to provide a magnetic disk device in which a plurality of disk disks can be accessed simultaneously with one magnetic head.

Another object of the present invention is to provide a magnetic disk device in which all recording track lengths are equal and the reliability of each track is constant.

[Means to solve the problem]

In order to achieve the above object, a rotary head having a plurality of magnetic heads arranged on the circumference is arranged at the center of a plurality of rotating disks.

[Effect]

According to the present invention, by arranging the rotary head at the center of a plurality of disk disks, it is possible to access a plurality of disks at the same time.

Further, according to the present invention, if the magnetic head on the rotary head uses only the time when it moves from the inside to the outside of the disc out of the locus it passes over the disc, recording tracks can be formed radially, and each By making the track lengths equal, the reliability of each track can be made constant.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail. Figure 1 shows
FIG. 2 is a top view and a sectional view when the present invention is applied to a magnetic disk drive having three disks. In FIGS. 1 and 2, 1 is a disk disk, and 2 is a rotating head. Three disks are arranged so that the center of rotation is located at the vertex of an equilateral triangle, and rotate clockwise at a constant speed. Further, the rotating head is arranged so that the center of rotation is located at the center of gravity of the equilateral triangle, and rotates clockwise at a constant speed. Six magnetic heads 3 are arranged at equal intervals around the outer periphery of the rotary head. The phase of the rotary head can be controlled by a phase control device 13. Here, phase control means, without changing the rotation speed,
This is to advance or delay the phase.

Of the trajectory that each magnetic head 3 passes over the disk disk (1), if only the time when the magnetic head 3 moves from the inside of the disk disk to the outside is defined as a recording track 6, then the recording track is on the disk disk (1). It is formed radially.

It is now assumed that the magnetic disk device is in an idle state and the magnetic head 3 is passing through every tenth recording track 6. Magnetic head A (4) is attached to disk disk 1 (5)
Track α. After passing through magnetic head B (7),
) is track b, which is 10 tracks ahead. Pass through (8).

Here, track b S (9
), the 1-phase control device 13 advances the phase of the rotary head and controls the magnetic head B (7) to pass over the track b S (9).

Furthermore, writing the same data to multiple disks at the same time is effective in improving database reliability.

In addition, the method of controlling the phase of the rotating head is inefficient when accessing multiple disks, so there is also a method that does not change the phase of the rotating head and instead controls the phase of each disk to position it to the target track. be. In this way, multiple disks can be operated in parallel.

In addition, the phase of both the rotating head and the disk disk is not changed, and the track that the magnetic head passes changes every time the disk disk rotates once.Then, after waiting for the required number of rotations, the target track is tracked. There is also a method of positioning.

This method simplifies the circuit because it does not require a phase control circuit, but increases the access time.

FIG. 3 shows an example of phase control.

The gold disk has an angular velocity ω. It is assumed that the phase at the 2nd time t is θ, and the movement is equal every day.

As shown in the figure, if the angular acceleration is +α from 1 time t1 to Δt, then the angular velocity ω1 at 1 time t1+Δt is.

ωuniω. 1αΔt −■. Next, if the angular acceleration is 1 α during Δt from time t2, then
The angular velocity ω2 at time t2+Δt is ω2=ω1−αΔt=ω. −■ becomes,
The initial angular velocity ω. Return to The phase θ2 at time t1+Δt is θ2=θ□+ω. Δ is 10 − α(Δt)2 − ■ Time t
The phase θ3 at 2 is.

θ3=02+ω1(12-1□−Δt) −■The phase θ at time t2+Δt is, θ4=θ3+ω1Δ above α(Δt)2 −■■,■
, Using the formula ■ and Tw=t2-tl −■, we get
Equation 0 is θ4=θ1+ω. M1 + (ω. ten α Δt) Tw
−■ becomes. Time t2+ when phase control is not performed
The phase θ- at Δt is θ;=61+ω. (Tw+Δt) −〇. The phase difference Δθ advanced by phase control is Δθ=θ, −
〇.

=α ΔtTw −■
becomes. If α and Δt are constant, the phase difference Δθ is proportional to Tw. Further, if α is positive, the phase can be advanced, and if α is negative, the phase can be delayed.

Since changing the time is disadvantageous in terms of access time, if Δt and Tw are constant, the phase difference Δθ is proportional to α.

The fourth column shows a sensor for one-phase control. In this example, the magnetic heads 3 are A, E,
There are 3 C, and the reference point hole 14 corresponds to C.
It also comes with 3 pieces.

The reference point hole 14 is made so that it is above the rotating head reference point sensor 12 when the reference head 3 is at the starting point 17 on the recording head 16 .

Reference numeral 15 denotes a track address recording section, which is present only on one side of the disk, and has track addresses recorded therein.

11 is a track address sensor. The track address sensor 11 indicates that the magnetic head 3 is on the recording track 1.
6, the track address of the recording track 16 is read and compared.

When the rotary head reference point sensor 12 detects the rotary head reference point hole 14, the output of the track address sensor 11 becomes the address of the track through which the magnetic head 3 passes.

FIG. 5 is an enlarged view of the track address recording section, in which the track address is recorded as the upper address 17 and the phase address 1.
It consists of two addresses of 8.

Figure 6 is an enlarged view of the track address sensor IJ.
Phase address sensor 20 and upper address sensor 21
It is composed of

Upper address sensor 21 reads upper address 17, and phase address sensor 20 reads phase address 18.
Read out.

FIG. 7 shows a block diagram of phase control.

The phase address calculation circuit 22 includes a phase address sensor 2
0 and the output of the rotating head reference point sensor 12, the phase address 49 through which the magnetic head 3 is currently passing is determined.

The address conversion decoder 28 converts the target track number 45 into an upper address 51 and a phase address 50. At this time, 43 address conversion truth tables are used.

The head number conversion decoder 29 obtains a head number signal 46 from the upper address 51. At that time, 44 head number conversion truth tables are used.

The magnetic head selector 42 receives the head number signal 46.

Select one magnetic head 3.

The phase difference calculator 23 calculates the difference between the phase address 50 output from the address conversion decoder 28 and the phase address 49 output from the phase address calculation circuit 22, and generates a phase difference signal 47.
make.

The rotation speed error calculation circuit 24 includes the rotation head reference point sensor 1
A rotation speed error signal 52 is generated using the output signal 53 of No. 2.

The rotation control circuit 25 generates a drive signal 48 from the 1 phase difference signal 47 and the rotation speed error signal 52.

The drive circuit 26 controls a mode 27 directly connected to the rotary head 2 based on the drive signal 48 .

FIG. 8 is a waveform of each part of the phase address calculation circuit, and FIG. 9 is a circuit diagram of the phase address calculation circuit.

The phase address sensor output 102 is -2, -1°0, +
1. +2. Take the 5 values of

Rotating head reference point sensor output 101 is connected to input terminal 111 of analog switch 106 .

When the rotating head reference point sensor output 101 is active,
The phase address appears at analog switch output 103. This is converted into digital signal 1 by A/D converter 107.
04 and held by the latch 108, a phase address signal 109 is obtained.

FIG. 10 is a circuit diagram of the rotation speed error calculation circuit.

A clock oscillator 113 uses a crystal oscillator 114 to generate a stable lock signal 112. Binary Kanta 1] 1 is
Count the clock signal 112. binary counter 11
Since the rotating head reference sensor output 119 is connected to the reset terminal 110 of No. 1, the binary counter 111 counts the clock signal at the pulse interval of the rotating head reference sensor output 119.

The difference between this counter output 115 and the specified value 116 is calculated using a subtracter 117 and a one rotation speed error signal 118 is generated.

〔Effect of the invention〕

According to the present invention, since a plurality of disks can be accessed simultaneously by using a rotating head, the apparatus can be miniaturized. Furthermore, since the track length can be made constant, there is an effect of making the reliability of each track constant.

[Brief explanation of drawings]

FIG. 1 is a top view showing one embodiment of the present invention, FIG. 2 is a sectional view thereof, FIG. 3 is a diagram showing an example of control to shift the phase without changing the angular velocity, and FIG. 4 is a diagram showing an example of phase control. Figure 5 is an enlarged view of the track address recording section, Figure 6 is an enlarged view of the track address sensor, Figure 7 is a block diagram of phase control, and Figure 8 is phase address calculation. FIG. 9 is a waveform diagram of each part of the circuit, FIG. 9 is a phase address calculation circuit diagram, and FIG. 10 is a rotation speed error calculation circuit diagram. 1...Disk disc 2...Rotating head 3...Magnetic head 稟 l Figure 4--To the warm air・To A Otsu-m-Track α0 7・-To the seven staffs・, FB 8- L, 7ri 2). ? ---Track b5 Shima 2 Diagram 3 Diagram 4- Diagram Collection 7 Diagram (α) Arithmetic 8 Diagram 9 Sekige m Atotos Jimoto Concave Meto o9

Claims (1)

Claims: (1) A magnetic disk device comprising a rotating head and a plurality of disk disks. (2) A formatting method for a magnetic disk device according to claim 1, wherein the recording tracks are radial. (3) The positioning method for a magnetic disk device according to claim 1, wherein the positioning method is performed by controlling the phase of the rotary head. (4) The positioning method for a magnetic disk device according to claim 1, wherein the positioning method is performed by controlling the phase of the disk disk. (5) The access method for a magnetic disk drive according to claim 1, wherein the number of rotations of the rotary head and the disk disk is kept constant, and the track to be passed changes every time the disk disk rotates once. (6) The positioning method of the access method according to claim 5, wherein the positioning method is performed by waiting for a necessary number of rotations. (7) A reliability improvement method in which the same data is written on each disk using the positioning method according to claim 3. (8) A simultaneous parallel control method for a plurality of disks using the positioning method according to claim 4. (9) Add an angular acceleration of Δt time + α from time t_1, add an angular acceleration of Δt time − α from time t_2, and change the phase to αΔt(t_2−t_1) without changing the angular velocity.
5. The phase control method according to claim 3, wherein the phase control method shifts the phase by a certain amount. (10) In the phase control method according to claim 9, the angular acceleration application time Δt and the application interval (t_2-t_1) are constant, and α
A phase control method characterized by changing the . (11) A rotary head characterized in that the magnetic head on the rotary head is set at the starting point of a track as a reference point, and at that time, a hole made on the rotary head passes over the sensor. Reference position detection method. (12) A disk track recognition method characterized by recording a track number using an analog signal on the outer periphery of a disk disk. (13) A passing track recognition method characterized in that when the output of the rotary head position detection sensor according to claim 11 is active, the track number according to claim 12 is recognized as a passing track.