JPS5835770A - Magnetic disc device - Google Patents

Abstract

PURPOSE:To make the position of a magnetic head at recording and at reproduction coincident, by moving the magnetic head up to an objective track in the step operation of a step motor and minutely adjusting a voltage of the step motor. CONSTITUTION:When a track to be accessed is instructed to an input terminal 12, a CPU 9 stores 11 the track number and reduces an output of a position correcting signal generating circuit 5 to zero, and reads out a present track number from a memory 10, generats 8 a pulse to the direction in which the difference will be readuced to zero, and drive a step motor 7 in step. When a magnetic head 2 reaches an objective track, the magnetic head 2 reads out position information written on a flexible disc in advance and the information is amplified 3, the position error is detected 4, and a position correcting signal is generated 5 and summed with an output of the pulse generating circuit 8 to turn a step motor 7 for a minute angle and to make the position error signal go to zero. Thus, the positioning can accurately be performed and the recording density can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic disk device equipped with a magnetic head positioning device at.

Flexible disk equipment is easy to handle.

Small combination due to low price cape, -Yuya Micro Combi A-
It has become widely used as an external storage device in the evening.

As a positioning device for a magnetic head in a flexible disk device, one using a stepwise motor is well known. The floor/motor is a tortoise that rotates at a constant angle in steps every time the drive current changes, so the steps rotate.

Rotating lead screen - or steel belt.

Instead, the magnetic head support is changed to step-like linear motion, and as a result, the magnetic head is moved in a stair 1 degree step by a fixed distance. In this way, the magnetic head
Radial direction of magnetic disk.

Positioning is performed by moving in steps. As described above, in a flexible disk device, the accuracy of the feeding mechanism is 1/f4 of the position of each track.

] with a certain deviation.

Moreover, the flexible disk itself is subject to eccentricity or expansion and contraction due to temperature, and the deviation in the relative position of the magnetic head to each track is approximately 100 μm or more. Therefore, in order to increase the storage capacity, the track density is increased (the track width tJ\ is reduced) and the magnetic head 1 is used when reading a track as shown in FIG.
The position of s/? may shift, and the data on the adjacent track 1b is also read, causing the data s/? v deteriorates and correct data cannot be obtained. At present, the track density is limited to 100 Tpl (rack/inch), and the demand for increased storage capacity has not been sufficiently met.

SUMMARY OF THE INVENTION An object of the present invention is to provide a flexible disk device that can accurately access track positions without the drawbacks of the prior art described above.

In the present invention, in order to achieve the above object, the magnetic head is made to reach the target track by the tapping operation of the stepwise motor, and when the magnetic head reaches the target track, the information written in advance on the voltage tube magnetic disk is applied to the stepwise motor. By detecting the position signal of the magnetic head and changing it slightly according to the deviation from the track, the position of the magnetic head during recording and playback can be matched, and the track can be accessed correctly even when the track density increases. Make it.

Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 2 is a block diagram showing one embodiment of the present invention. In FIG. 2, 2 is a magnetic head, 3 is a preamplifier, 4 is a position error detection circuit, 5 is a position correction signal generation circuit, 6 is an addition circuit, 7 is a linear motor, 8 is a pulse generation circuit, and 9 is a In the control section, 10 is a current track number storage circuit, 11 is a target track number storage circuit, and 12 is a control signal input terminal.

As the magnetic head 2 rotates, the magnetic head moves in the direction of the inner diameter of the magnetic disk.

'First, when a command to move the magnetic head to a specific track is inputted to the control signal input terminal 12, the control section 9 stores the track number sound in the target track number storage circuit 11, and then generates a position correction signal. Set the output of circuit 5 to 0,
The track number currently being accessed by the magnetic head is read from the current track number storage circuit 10, and information on the rotational direction of the stepping motor 70 is obtained from the difference. This information)
The control unit 9 controls the pulse generating circuit 8 to rotate the stepwise motor 7t, and as a result, the magnetic head 2 is moved by one track. The control section 9 increments or increments the magnetic field by the current track number storage circuit 10t-1 every time the track 2 moves one track. The control unit 9 controls the movement of the magnetic head 2 by one track, that is, the stepwise motor 7.
The pulse-like rotation is repeated until the contents of the current track number storage circuit 10 match the contents of the target track number storage circuit 11. That is, in this way, the magnetic head 2 arrives very close to the predetermined track. Next, when the magnetic head 2 reaches a predetermined track, the magnetic head 2 reads out the position information written on the flexible disk in advance, and amplifies it to the preamplifier 5, which causes a 1st position difference. The zero position correction signal generation circuit 5, in which the position mIII difference signal is detected by the detection circuit 4, controls the output of the pulse generation circuit 12 in accordance with the detected position mIII difference signal.

At this point, the control section 9 outputs the output to of the position correction signal generation circuit.
discontinue doing so. In this way, the rotary motor is rotated by a minute angle so that the position error signal obtained from the position information obtained from the 7-wire magnetic head 2 becomes zero. Therefore, the magnetic head 2 completely runs on the predetermined track. From the pre-written location information,
Regarding the method of detecting the positional error, many patents have been filed and known techniques can be used in the present invention, so a detailed explanation will not be given here.

Next, the floor dynamic motor will be explained. As is well known, the floor dynamic motor includes the 2M type (permanent magnet fjl), the VR type (variable reluctance wheel), and the composite type (hybrid type). In flexible disks, a small angle, high torque hybrid type is often used, so the hybrid type will be explained. Also, there are three driving methods: one-phase excitation, two-phase excitation, and 1-2-phase excitation. Here, the two-phase excitation method with good transient characteristics will be explained. The same operation as in the electric current embodiment is possible using other excitation methods. Figure S shows an example of a floor motor. In FIG. 5, 1s is a stator, 14 is a rotor, and 15 is a permanent magnet. A rotor 14 rotates within the stator 1S. The stator 15 is wound with windings A and E as shown in the figure. Figure 4 shows the driving current.Winding A in Figure 3 has a current like the first phase shown in Figure 5, and similarly, winding B has a current like the second phase. shall flow. In FIG. 4, the symbols ←) and θ represent the direction of the current flowing through each winding, and the vertical axis represents its magnitude.

When the electric current rlL is changed as in a → b → c - e d . To reverse it, it can be simplified as l→f→−→d...

For example, when accessing a specific track as described above, it is assumed that the first floor motor reaches the target track at the position shown in FIG. 4C.

At that time, current flows through each winding of the stepwise motor as shown by the dot-dashed line in Figure 5.d In order to move the magnetic head position at a minute distance, it is necessary to move the magnetic head at the position shown by the solid line in Figure 5. In other words, in order to move the magnetic head a small distance from the position shown in FIG. 4C to the position shown in FIG. All you have to do is reduce the current. Conversely, in order to move the magnetic head from the position C in Figure 4 to the position □□□b in Figure 4, the current in the first phase may be decreased without changing the second phase. In this example, the magnetic head movement was explained from position C, but the same control can be performed at other positions as well. As is clear from Figures 4 and 5, the method is to compare the drive currents of each phase at the current position and the adjacent position, and if they are the same, the current of that phase is not changed; When it is reversed, by decreasing the absolute value of the current in that phase, the position can be moved slightly in the direction of the adjacent position. FIG. 6 shows an embodiment of the pulse generation circuit and stepwise motor drive circuit. In FIG. 4, 16 is a power supply terminal, 17 to 24 are switches, 25.26 is a constant current source, 27 is an error signal input terminal, 2 is a position correction signal generation circuit, 29 is a switch drive circuit, and sea control signal input Terminals 51 and 52 are the windings of the stepping motor. switch 1
7 to 24 are connected to 17 and 20 by the switch drive circuit 29.
．． 18, 19.21, 24.22 and 2M are operated in pairs, respectively. As a result, a current as shown in FIG. 4 flows through the windings 51 and 52 of the step motor. Further, the magnitude of the current of the constant current sources 25 and 24 is controlled by the output of the position correction signal generation circuit 28.

Further, the position correction signal generation circuit 2S is a switch drive circuit 2.
? As mentioned above, depending on the output state of the constant voltage aS25.
The magnitude of the current of 24 is changed. Regarding the operation, similar to the embodiment shown in FIG. 3, in order to move the magnetic head stepwise to the target track, a control signal is input to the control signal input terminal !IO of the switch drive circuit 290. In that case, the control of the constant current sources 25*24 by the position correction signal generation circuit 28 is stopped.The switch drive circuit 29 controls the switches 17 to 24 so that current flows through each winding 5132 as shown in FIG. When the magnetic head reaches the target track, the position correction signal generation circuit 2S
depends on the titwA difference signal obtained from the magnetic head applied to the error signal input terminal 27 and the state of the switch drive circuit 29, so that the constant current source 25 or the constant current source 24 is switched to the fourth
The control is performed as explained using FIGS.

As explained above, one aspect of the present invention is a flexible disk device that uses a stepwise motor to move a pulsed Ki/Ki head based on a position error signal from a magnetic disk.
By applying a track servo to the linear motor, it becomes possible to accurately position the head, which can be used for high track density, ie, large capacity, flexible disk drives.

[Brief explanation of drawings]

the magnetic head 2.1 4-mae Geki Amplifier Standard tp difference detection circuit &Position correction signal generation circuit 2nd floor motor &Pulse generation circuit Negative control section 111L Current track number storage circuit 11 Target track number storage circuit 15 stator 14, rotor 15. Permanent magnet 2 & position correction signal generation circuit 29, switch drive circuit Figure 11 3rd figure − Talent 4 Figure 2s diagram Talent 6 Figure 6

Claims (1)

[Claims] t. A magnetic disk having a plurality of tracks. a stepwise motor, a magnetic head, a device for moving the skeleton magnetic head in a radial direction of the magnetic disk in a pulsed manner using the output of the stepwise motor, and a pulse generator for driving the stepwise motor. In a magnetic disk device equipped with Equipped with a circuit that adds the outputs of the error detection circuit, the 1-position frame difference detection circuit, and the output of the pulse generator,
When performing magnetic head positioning, the stepwise motor is moved by the output of the pulse generator until the target track is reached, and after the magnetic head reaches the target track, the stepwise motor is driven by the output of the adder circuit. Magnetic disk device with % mold. 2. In the magnetic disk drive according to claim 1, the output state of the pulse generation circuit. A magnetic disk drive in which the electric current fILt- and Vat of at least one winding of a stepwise motor is changed by a voltage difference signal tWA.