JPH02240878A - Head feeder - Google Patents

Abstract

PURPOSE:To shorten the access time with a simple circuit constitution by providing plural diving motors and driving a step feed and a heavy head carriage with separate motors. CONSTITUTION:A stepping motor 12 drives a movable member 9 and a voice coil motor 15 arrives a heavy head carriage 2. A magnetic head 1 and the carriage 2 are fitted to a supporting member 5 via a spring member 3. The member 5 has through-holes, shafts 6a, 6b are penetrated therethrough, the head 1 and the carriage 2 are made slidable and a moving route is regulated. Moreover, a position detection means 8 having a light receiving element 8a is fixed to the supporting member 5. The detection means 8 receives the light from the light emitting element 9a of the movable member 9 at an opposite position to detect the position. The step feed of the motor 1 is controlled independently in response to the detection and the access time is shortened with the simple constitution.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to, for example, a head feeding device for a magnetic disk drive.

[Summary of the invention]

The present invention is a head feeding device that transports a magnetic head to a predetermined track position on a magnetic disk, and includes a motor that drives a movable member to step feed, a voice coil motor that feeds and drives a head carriage, and at least one of the movable member and the head carriage. By having a position detecting means installed on one side and detecting the position of the other, and controlling the step feed of the head by a voice coil motor according to the output from the position detecting means, the access time is shortened and the device is The present invention provides a head feeding device that is small in scale and has a simple circuit configuration.

[Conventional technology]

Traditionally, with the increase in track density of magnetic disks, the magnetic head has been moved to the fine movement side? A variety of drive devices and methods are available for driving 1l (racking servo). In particular, voice coil motors are widely used as the drive device for hard disks, etc., and in this case, track movement is first performed (coarse movement control), and then fine movement control is performed based on tracking information. . Therefore, head position detection means for coarse movement control is required here, and one example of such means is a device that detects the head position using an optical scale.

Furthermore, as an alternative to the above method, there is a method in which a stepping motor is used as the drive device.

In the stepping motor, since the amount of feed per step is determined, the head position can be easily detected by counting the number of steps.

[Problem to be solved by the invention]

However, when detecting the head position using the above-mentioned optical scale, there is a risk that the precision of the scale may deteriorate due to expansion and contraction due to aging or temperature changes. In addition, the optical scale itself is thick (and heavy), which makes it difficult to miniaturize the device.High processing precision is required for engraving the scale, making it expensive, which also has a disadvantage in terms of cost.

Additionally, when an optical scale is used, a circuit configuration for position reading is required.

Further, in the method using a stepping motor, since the head carriage is moved by the stepping motor, a load is applied to the stepping motor, and therefore the access time is limited and the response becomes poor.

In addition, since the stop positions of the magnetic head are generally given discretely, it is necessary to perform very fine feed control for fine movement control, which results in long access times and also reduces the hysteresis of the stepping motor. There are also problems.

In this respect, a voice coil motor that moves in an analog manner and is capable of continuous positioning can be said to be more advantageous than a stepping motor because it allows fine feed control. but,
The voice coil motor has a disadvantage in that it cannot move the head to a predetermined track without a means for detecting the position of the head.

Therefore, considering these factors, it is conceivable to use a stepping motor for coarse motion control and a voice coil motor for fine motion control.

However, there still remains a limit on the time for moving the head carriage with the stepping motor (limitation on access time), which is disadvantageous in terms of space as well when considering miniaturization.

Therefore, the present invention has been proposed in view of the above-mentioned actual situation, and allows the device to be compact, access time is short, and
It is an object of the present invention to provide a head feeding device with a simple circuit configuration.

[Means to solve the problem]

The present invention has been proposed to achieve the above-mentioned object, and as shown in FIG.
, a voice coil motor 15 for feeding and driving the head carriage 2, and a position detecting means 8 provided on at least one of the movable member 9 and the head carriage 2 to detect the position of the other. The present invention is characterized in that the voice coil motor 15 performs step feed control of the head 1 in accordance with the output from the means 8.

[Effect]

According to the present invention, the head is coarsely controlled by the motor that drives the movable member in steps, and the head is finely controlled by the voice coil motor that feeds and drives the head carriage.
-, there is. Furthermore, the movable member and the head carriage are spatially separated by the position detection means, and the step feed control of the head is performed by the voice coil motor in accordance with the output from the position detection means, so the access time is short.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. It goes without saying that the present invention is not limited to the following examples.

1A and 1B schematically show the general configuration of the head feeding device of this embodiment, FIG. 1A shows a plan view of the device, and FIG. 1B shows a one-dimensional view. A partially broken side view is not shown.

1A and 1B, the chassis 21 includes, for example, a 3.5-inch floppy disk 19, a disk drive motor 24, a voice coil motor 15, and a shaft 6.
A, 6bx stepping motor 12, lead screw 11, and guide rail IO are fixed. Note that the voice coil motor 15 is fixed to the chassis 21 with fixing screws 18. In addition, the above floppy disk 1
The hub 23 of No. 9 is positioned by the rotating shaft 24a of the disk drive motor 24 and attracted by magnetic force.

Therefore, the magnetic disk 20 is rotated together with the hub 23 by the disk drive motor 24. That is, this embodiment describes an example of tracking control in a so-called floppy disk drive device.

Here, the magnetic head 1 and head carriage 2 are attached to a support member 5 with a fixing screw 4 via a spring member 3. The support member 5 has two through holes, through which the shafts 6a and 6b pass, so that the support member 5 can slide and its movement route is regulated by the shafts 6a and 6b. ing.

A position detection means 8 having a light receiving element 8a is fixed to the support member 5 by a fixing screw 7.

The position detecting means 8 detects a movable member 9 at an opposing position.
The position of the light-emitting element 9a is detected by receiving light from the light-emitting element 9a disposed in the light-emitting element 9a. That is, the position detection means 8 and the movable member 9 are spatially separated. Note that the light reception signal of the light receiving element 8a of the position detecting means 8 is sent to a control circuit to be described later.

Here, the movable member 9 located at a position facing the position detecting means 8 is provided with a through hole through which the guide rail lO passes and a screw hole for the lead screw 11. The movable member 9 is moved by rotation, and the guide rail 10 regulates the sliding movement and movement route of the movable member 9. Further, the lead screw 11 is directly connected to the stepping motor 12 that drives the movable member 9 in steps, and the rotation of the stepping motor 12 causes the lead screw 11 to rotate. The stepping motor 12 is controlled in steps by a control circuit that will be described later.

Further, the coil 1 is attached to the support member 5 by a fixing screw 13.
4 is installed. That is, the coil 14 is the movable coil 14 of the voice coil motor 15 that feeds and drives the head carriage 2. Here, the voice coil motor 15 has opposing magnets 16a, 1
6b and a rail 17, the coil 14 is moved by the current flowing through the magnets 16a, 16b and the winding of the coil 14, and the rail 17 controls the sliding and movement route of the coil 14. There is. Note that the voice coil motor 12 is controlled by a control circuit that will be described later.

That is, the movable member 9 is moved step by step by controlling the stepping motor 12 to rotate the lead screw 11, and therefore the position detecting means 8 which has received the light from the light emitting element 9a of the movable member 9 is A light reception signal from the light receiving element 8a is processed by a control circuit, which will be described later, and the control signal is supplied to the voice coil motor 15, and the movable coil 14 of the voice coil motor 15 is moved. In other words, based on the coarse movement step and knob control of the stepping motor 12, the voice coil motor 15 controls the step-feeding of the magnetic head l disposed on the head carriage 2 to near a predetermined track position on the magnetic disk 20. Furthermore, the magnetic head 1 is finely controlled by the voice coil motor 15 to perform tracking servo and war on a predetermined track.

Note that the light receiving element 8a of the position detecting means 8 and the movable member 9
It is also possible to replace the light emitting elements 9a with each other.

In this case, the light receiving element disposed on the movable member 9 detects the position of the light emitting element of the position detecting means 8 and sends it to a control circuit to be described later.

FIG. 2 shows a control circuit that performs feeding control of the stepping motor 12 and voice coil motor 15 and signal processing of the light receiving element 8a of the position detecting means 8.

In FIG. 2, the input terminal 30 has a host terminal (not shown).
A step feed control signal sent from the computer is input. This step feed control signal is a signal sent according to a predetermined program, and is a signal composed of a signal that controls the rotation direction of the stepping motor 12 and a step pulse that indicates the step feed amount. In some cases, the signal is sent as a track designation signal that designates a predetermined track on a magnetic disk.

These step feed control signals are input to the input signal processing circuit 3.
1 is man-powered. The circuit 31 receives the step feed control signal and controls the step feed of the voice coil motor 15 based on the step feed of the stepping motor 12 to move the magnetic head 1 to the vicinity of a predetermined track. A step pulse is generated and supplied to the distribution circuit 33. The distribution circuit 33 outputs an excitation pattern indicating the phase of the stepping motor 12 for each step pulse, and outputs this pattern to the stepper drive circuit 34. The stepper drive circuit 34 supplies current to each phase of the stepping motor 12 in a direction determined by the excitation pattern. The voice coil motor 15 moves the head carriage 2 and the light receiving element 8a of the position detecting means 8 attached to the head carriage 2 in order to send the magnetic head 1 to a target track. Here, FIG. 3 shows the sensor level signal (analog signal) of the light-receiving element 8a, which reaches its peak value when the relative distance to the light-emitting element 9a is closest, that is, when the received light intensity is maximum, and when they are far apart from each other. It decreases over time. This sensor level signal is transmitted to the A/D conversion circuit 40 via the changeover selection switch 47, where A/D conversion is performed, and then taken into the controller of the servo circuit 41.

The servo circuit 41 operates the voice coil motor 15 so that the sensor level of the light receiving element 8a is always at its peak while monitoring the sensor level of the light receiving element 8a during the step accompanying the feeding of the stepping motor 12. That is, the light emitting element 9a of the movable member 9 moved by the stepping motor 12
The head carriage 2 follows. Specifically, the sensor level (peak) of the light receiving element 8a when the relative distance at the time of initialization becomes 0'' is latched, and the sensor level signal is captured every time a step is taken, and the peak (or its vicinity) is detected. The voice coil motor 15 is stopped at the point where the magnetic head 1
is sent to the destination track. Further, the operation control voltage for the voice coil motor 15 is provided to the voice coil motor drive circuit 43 by D/A converting the output data (digital data) of the servo circuit 41 by the D/Ai conversion circuit 42 .

After the magnetic helad 1 reaches the target track as described above, fine movement control is performed by the voice coil motor 15 on that track.

Here, data for tracking servo is written on the magnetic disk 20 in a recording format as shown in FIG. That is, FIG. 4 is an enlarged view of a part of the magnetic disk 20, which schematically shows the track direction developed linearly. Servo ID signal pattern 52 as servo data. . and servo burst signal pattern 52. It is constructed by disposing a servo area S consisting of.

Here, the tracking servo data is read by the magnetic head l, signal amplified by the amplifier 45, envelope detected by the envelope detection circuit 46, and sent to the A/D conversion circuit 40 via the changeover selection switch 47. The signal is then A/D converted by this A/D conversion circuit 40 and then sent to the servo circuit 41. Note that the envelope waveform EN from the envelope detection circuit 46 is as follows:
The waveform becomes as shown in FIG. Note that the data area and the servo ID signal pattern 521° are detected waveforms shown by broken lines in the figure.

Further, the changeover selection switch 47 is connected to the servo circuit 4.
The sensor level signal and the envelope detection signal inputted to the A/D conversion circuit 40 are switched and selected.

That is, to summarize the above, in the case of coarse movement control of the magnetic helad l, a signal from the input signal processing circuit 31 based on the step feed control signal causes
The stepping motor 12 is subjected to coarse step feed control, and the servo circuit 41 controls the changeover selection switch 47 to connect the terminals 47a and 47c.

As a result, the sensor level signal from the light receiving element 8a is supplied to the servo circuit 41, and the servo circuit 4-
1 controls the voice coil motor 15 in steps based on the sensor level signal.

That is, the magnetic head 1 disposed on the head carriage 2 transported by the voice coil motor 15 is sent near a predetermined track.

When performing fine movement control of the magnetic head 1, that is, tracking servo, when the magnetic head 1 reaches the vicinity of a predetermined track as described above (that is, based on the step feed control signal), the servo circuit 41 The switching selection switch 47 is controlled to connect the terminals 47b and 47c. As a result, the magnetic head l
The tracking servo data read by is supplied to the servo circuit 41, and the servo circuit 41 controls the voice coil motor 15 based on the tracking servo data, so that the magnetic head l scans a predetermined track (tracking servo). is possible.

That is, since the apparatus of this embodiment detects the position of the magnetic head 1 without using the optical scale as described above, the apparatus can be made smaller.

In addition, since the stepping motor 12 for coarse movement control and the head carriage 2 are spatially separated by the light receiving element 8a and the light emitting element 9a, and step feed control is performed by the voice coil motor 15, the access time is fast. The magnetic head 1 can be moved near a predetermined track.

In addition, in the case of this embodiment, the light receiving element 8 is used for position detection.
Since only the case where the sensor level signal of a reaches its peak is required, there is no need to adjust the amount of light.

Note that since the fine movement control is performed by the voice coil motor 15, highly accurate tracking servo can be performed.

Further, in the above embodiment, a light receiving element (or a light emitting element) is provided in the position detecting means 8, and the movable member 9
A light emitting element (or a light receiving element) is disposed in the position detecting means 8, and the position of the movable member 9 is detected by disposing, for example, a photointerrupter in the position detecting means 8 and blocking the light from the photointerrupter with the movable member 9. It is also possible to do so. That is,
In this case, since the movable member 9 is used only to block the light from the photointerrupter, there is no need to attach a light emitting element or the like, and the reverse case is also possible. Note that the present invention is not limited to optical position detecting elements, and for example, mechanical detecting elements, magnetic detecting elements, etc. can be used in the same manner.

[Effects of the Invention] In the present invention, the step-feed driving motor does not feed and drive the heavy head carriage, but the voice coil motor feeds and drives the head carriage, so access time can be shortened and the scale of the device can be reduced. It has become possible to obtain a head feeding device that is small and has a simple circuit configuration.

[Brief explanation of drawings]

FIG. 1A is a schematic plan view of the device of this embodiment, FIG. 1B is a partially cutaway side view of the device of this embodiment, FIG. 2 is a block circuit diagram showing the control circuit of the device of this embodiment, and FIG. The figure is a characteristic diagram showing the sensor level of the light receiving element, and FIG. 4 is a schematic diagram showing the recording format on the magnetic disk.・ ・ ・ ・ 2 ・ ・ ・ 8 ・ ・ ・ 8a ・ ・ 9 ・ ・ ・ 9a ・ ・ l 2 ・ ・ l 4 ・ ・ l 5 ・ ・ 3 l ・ ・ 33 ・ ・ 34 ・ ・ 40 ・ ・ 4 l ・・ 42 ・ ・ 43 ・ ・ 46 ・ ・ 47 ・ ・ 52+m Circuit, stepper, drive circuit, A/D conversion circuit, servo circuit, D/A conversion circuit, voice coil motor drive circuit, envelope detection circuit, changeover selection switch, servo ID signal pattern, servo burst signal pattern

Claims (1)

[Scope of Claims] A motor that drives a movable member in steps; a voice coil motor that drives a head carriage; and a position detector provided on at least one of the movable member and the head carriage to detect the position of the other. 1. A head feeding device comprising: means for controlling step feed of the head by the voice coil motor in accordance with an output from the position detecting means.