JP2501025B2 - Head-to-edge squeeze mechanism - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a head carriage seek mechanism, and more particularly to a head carriage seek mechanism used in a magnetic disk device.

[Prior Art] A magnetic disk drive requires a head seek mechanism that moves a head by some means to determine a track position.

A stepping motor has been widely used as a drive source for such a head seek mechanism.

Conventional examples of such a head seek mechanism are shown in FIGS.
Shown in the figure.

In FIG. 1 and FIG. 2, the reference numeral 1 indicates the substrate of the apparatus, and the stepping motor 2 is attached by the screw 3 and the nut 4.

Reference numeral 5 indicates a head carriage, a guide bar 6,
6 will guide you left and right in FIG.

Both ends of the guide bars 6, 6 are supported by the indicating member 7.

A pulley 8 is fixed to the output shaft of the stepping motor 2, and a part of a steel belt 9 whose both ends are fixed to the head carriage 5 is wound around the pulley 8.

Therefore, when the pulley 8 of the stepping motor is rotated, the steel belt 9 is wound around and the head carriage 5 is moved left and right to perform head seek depending on the rotation direction.

On the other hand, the reference numeral 10 is a photo sensor for detecting the position of the track "00", and the protrusion 5a of the head carriage 5 is inserted between the light emitting element and the light receiving element arranged above and below to detect the position. To do.

The photo sensor 10 is attached to the substrate 1 side with a screw 12 via a mounting plate 11.

In the head seek mechanism having such a structure, the cost of the stepping motor affects the cost of the entire mechanism, and it is extremely difficult to reduce the cost.

Further, for the adjustment of the track "00" position and the track position adjustment, the photosensor 10 and the stepping motor 2 are rotated or moved in the direction of the arrow shown in FIG.
A method of fastening the screws 3 and 12 to fix them is adopted.

For this reason, the position adjustment is delicate, and even if it is adjusted once, there is a drawback that the adjustment will be incorrect if it is tightened with the screw.

[Purpose] The present invention has been made in order to eliminate the above-mentioned conventional drawbacks, and it is possible to realize cost reduction and to perform a track position adjustment accurately and easily. It is intended to provide a mechanism.

[Examples] Hereinafter, the details of the present invention will be described with reference to Examples shown in the drawings.

FIG. 3 and the following figures explain one embodiment of the present invention, and FIG. 3 shows the entire head seek mechanism.

A reference numeral 13 in FIG. 3 is a linear solenoid, and a connecting fitting 15 formed in a substantially U-shape is fixed to the tip of a rod 14 by a screw 16.

A carriage 18 is provided above the connection fitting 15 via a leaf spring 17.
And a magnetic head 19 is fixed to the carriage 18.

Further, a lower carriage 21 is attached to the lower side of the connection fitting 15 with a screw 20, and a magnetic head 22 is fixed to the upper side of the carriage 21 so as to face the magnetic head 19.

On the other hand, a spring receiver 23 is fixed together with the leaf spring 17 by a screw 24, and a spring 25 is mounted between the spring receiver 23 and the leaf spring 17.

A spring 27 is stretched between the tip of the lower carriage 21 and the fixing portion 26 of the device.

By the way, the linear solenoid 13 has a structure as shown in FIG.

In FIG. 4, reference numeral 28 denotes a cylindrical yoke, and coil bobbins 29, 29 are accommodated in the yoke 28, and a coil 30 is wound around these coil bobbins.

Further, the reference numeral 31 is a pole piece, and the permanent magnet 32
It is fixed on both sides of.

The rod is passed through the coil bobbin 29 and the permanent magnet 32.
14 is slidably fitted.

 Reference numeral 33 indicates a bearing.

In the linear solenoid 13 having such a structure, as shown in FIG. 5, the current I and the force F generated by flowing this current have a proportional relationship up to the saturation current value Io.

When the force F shown in FIG. 5 is generated, the rod 14 moves, the carriages 18 and 21 are advanced through the connecting fitting 15, and the spring 2
7 are compressed.

A repulsive force F'is generated by this compression. When the repulsive force F'becomes F '= F, the movement of the rod 14 stops, so that the movements of the carriages 18, 21 and the magnetic heads 19, 22 also stop.

When the amount of movement of the magnetic heads 19 and 22 at this time, that is, the contraction length of the spring 27 is X, F ′ = kX (k is a spring constant)
Since F = F ', KI = kX and I = (k / K)
X = CX.

 Note that K and C are constants.

That is, the movement amount X of the magnetic heads 19 and 22 is proportional to the current I flowing through the coil 30.

By the way, the drive circuit of the linear solenoid 13 is shown in FIG.

In FIG. 6, the reference numeral 34 indicates a binary counter.
An analog switch 35 is connected to each of the outputs Q _{1 to} Q ₆ of the IC.
~ 40 are connected.

Reference numerals 41 to 46 denote resistances R _{1 to} R ₆ , and reference numeral 47 denotes a variable resistance.

 Reference numeral 48 is a variable voltage source, and 49 is a variable resistor.

Next, the operation of the seek mechanism will be described with reference to FIG.

First, the binary counter IC34
Decide whether to count up or down. Then, when a step signal is input to the clock terminal of the binary counter IC34, a count number equal to the number of tracks is output.
Appears in Q _{1 to} Q ₆ .

Here, the current flowing through the resistors R _{1 to} R ₆ is I _{1 to} I _6, and I ₆ = 2I
_{If 5} = 4I ₄ = 8I ₃ = 16I ₂ = 32 ₁ , then Vcc = R ₁ I ₁ = R ₂ I ₂ = R
₃ I ₃ = R ₄ I ₄ = R ₅ I ₅ = R ₆ I ₆ and R ₁ = 32Vcc / I ₆ , R ₂ = 16V
cc / I ₆ , R ₃ = 8Vcc / I ₆ , R ₄ = 4Vcc / I ₆ , R ₅ = 2Vcc / I ₆ , R ₆ =
It becomes Vcc / I ₆ .

Therefore, R ₁ = 2R ₂ = 4R ₃ = 8R ₄ = 16R ₅ = 32R ₆ .

That is, if the values of the resistors R _{1 to} R ₆ are determined as described above, a digital current value proportional to the count number, that is, the track number can be created.

The power supply voltage Vcc is the output of the variable voltage source 48 and can be made variable by the variable resistor 49.

Also, since there is a relationship of X∝F∝I∝Vcc, the moving amount of the magnetic head can be changed by changing Vcc.
Therefore, the track position can be adjusted.

[Effect] As is apparent from the above description, according to the present invention, in the head carriage seek mechanism, conventionally, the position in the non-excited state can be set without using a drive system using an expensive and complicated step motor. The linear solenoid, which is merely used for the two-point position control of the excitation position when a saturation current is applied, can be controlled like a step motor according to the head moving clock pulse. In applying this to the head carriage seek mechanism, the head carriage is urged in one direction by the urging means, and the linear solenoid is driven against the urging, and the urging force and the driving force of the linear solenoid are The head carriage is moved to each recording track by the balance, and the current supplied to the linear solenoid is counted by the clock pulse for the head feed supplied from the outside, and the current is weighted according to the count value. It was changed by conversion so that the linear solenoid could be moved stepwise to any track position.

As a result, the structure is simple and low cost, and since the balance with the biasing means is used, the driving force of the linear solenoid is always the same in one direction, and rattling of the head carriage can be prevented. Accurate track position adjustment,
An excellent effect that it can be performed stably and easily is obtained.

[Brief description of drawings]

1 and 2 are a plan view and a bottom view for explaining a conventional apparatus, and FIG. 3 and the following figures are for explaining one embodiment of the present invention.
FIG. 3 is a side view of the seek mechanism, FIG. 4 is a partially longitudinal side view of the linear solenoid, FIG. 5 is a diagram showing the relationship between current and output of the linear solenoid, and FIG. 6 is a block diagram of the drive circuit. Is. 13 ... Linear solenoid 14 ... Rod 18, 21 ... Carriage 19, 22 ... Magnetic head 27 ... Spring 34 ... Binary counter IC 35-40 ... Analog switch 41-46 ... Resistor 47, 49 ... Variable resistance 48 ... Variable voltage source

Claims (1)

(57) [Claims] 1. A head carriage to which a head is attached and which is arranged so as to be movable to a plurality of recording tracks formed on a disk-shaped recording medium, and a biasing force for biasing the head carriage in one direction of its moving direction. Means for driving the head carriage against the biasing means,
A linear solenoid as a drive source for positioning the head carriage by the driving force and the urging force of the urging means and a clock pulse for head feeding according to a target movement position of the head supplied from the outside are counted. And a drive circuit that generates a drive current according to the count value and supplies the drive current to the linear solenoid to drive the linear solenoid in a stepwise manner. The urging means for moving the head in the one direction of the moving direction. The linear solenoid is used to move in the direction opposite to the one direction, and the moving position of the head between the plurality of recording tracks is determined by the number of clock pulses supplied from the outside. A head carriage seek mechanism characterized by being configured to control.