JPH0528678A - Access mechanism in recording and reproducing device - Google Patents

Abstract

PURPOSE:To obtain stable access mechanism without the influence of unnecessary force due to the wet magnetic flux line of VCM by forming the supporting component of a pressing means pressing a magnetic head to a recording medium by means of non-magnetic material. CONSTITUTION:The magnetic heads 8 and 9 are attached to a carriage 1 and a head arm 3 and the head arm 3 is attached by a screw 52 together with a spring hanging plate 50. The spring hanging plate 50 is provided with a pressing spring 51 for pressing the magnetic heads 8 and 9 to the recording medium 10 and the head arm 3 and the spring 51 constitutes a pressing means. The spring hanging plate 50 is made of non-magnetic material such as phosphor bronze. Therefore, the wet magnetic flux line of the magnet 19 in VCM 13 is prevented from giving unnecessary force to the movable part of access mechanism so that stable access mechanism is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an access mechanism of a recording / reproducing apparatus, and more particularly, to a recording medium by moving a recording / reproducing head to a desired track position among a plurality of tracks formed on a disk-shaped recording medium. The present invention relates to an access mechanism of a recording / reproducing apparatus that records / reproduces information according to the above.

[0002]

2. Description of the Related Art As a recording / reproducing apparatus of this type, a floppy disk drive device (hereinafter referred to as FDD) for recording / reproducing information on / from a flexible magnetic disk, which is a so-called floppy disk used in an external storage device of a computer. ).

In recent years, the capacity of FDD has been rapidly increased, and accordingly, the head access time has been required to be shortened. In order to meet this demand in recent years, a voice coil motor (hereinafter referred to as VCM), which is advantageous in increasing the speed, has been adopted in a head access mechanism.

The magnetic head access mechanism will be described with reference to FIG. The magnetic head access mechanism (magnetic head seek mechanism) has a VCM 13 as a drive source.
A magnet 19 is provided inside the yoke 18 of the CM, and a coil 20 attached to the carriage 1 is provided.
Are arranged so as to face the magnet 19. When a current flows through the coil 20, the carriage 1 is linearly moved by the interaction between the magnetic field generated in the coil and the magnetic field generated in the magnet 19. That is, coil 2
0 and the magnet 19 constitute a linear motor, and the carriage 1 is moved by this linear motor.
The head arm 3 is attached to the carriage 1 together with a spring hooking plate 50 with screws 52. The spring hook plate 50 is provided with a spring 51 for pressing the recording / reproducing heads (magnetic heads) 8 and 9 to be described later against the recording medium 10.

Further, the carriage 1 has a plurality of rollers 2
1 is installed at an arbitrary angle and preload 22
Is composed of a roller 22a and a load spring 22b for pressing the roller 22a against the first guide bar 23 and the second guide bar 24.
The guide bars 23 and 24 are elastically supported between the guide bars 23 and 24 via the rollers 21.
Guided by, the seek can be performed in a direction approaching the center of the recording medium 10 and a direction leaving the center of the recording medium 10 to move to a predetermined track position.

Further, a linear scale 15 is provided in parallel with the guide bars 23 and 24, and slits 15a are formed in the linear scale 15 at equal intervals. The sensor 25 and the linear scale 15 form an encoder 26) that moves along the linear scale 15 when the carriage 1 moves linearly. Sensor 25
Like the conventional example, has a light emitting element and a light receiving element (not shown). Light emitted from this light emitting element is received by the light receiving element through the slit 15a of the linear scale 15, and the sensor 25 moves. Positioning of the sensor with respect to the linear scale and thus positioning of the recording heads 8 and 9 with respect to the track of the recording medium 10 is performed by the number of signals generated when light is received by the light receiving element.

[0007]

However, in the access mechanism of the recording / reproducing apparatus described above, it is necessary to make the mechanical resonance frequency of the carriage as high as possible, and the action line of force of the VCM 13 as a drive source. It is important that the centers of gravity of the moving parts of the carriage 1 and the carriage 1 are closer to each other. As a result, the VCM 13 and the head arm 3 mounted on the carriage come close to each other, and the spring hooking plate 50 is also attached to the VCM 13.
Will be close to. By the way, in the VCM 13, the main magnetic flux line A of the magnet 19 is generated as shown in FIG.
This acts on the coil 20, but a part of it leaks as shown in FIG. 5, so that a leakage magnetic flux line B is generated. For this reason, when the spring hooking plate 50 is made of a magnetic material as in the conventional case, the leakage magnetic flux line B is generated by the spring hooking plate 50.
And the movable part such as the carriage 1 acts on the magnet 19
There was a drawback that it could not be stably accessed (seek) because it was sucked into.

Therefore, it is an object of the present invention to provide an access mechanism for a recording / reproducing apparatus in which a movable part such as a carriage of the access mechanism is constructed so as not to be affected by the magnetic flux of a magnet and the above-mentioned drawbacks are solved. It is in.

[0009]

To achieve the above object, the present invention provides at least one recording / reproducing head in an access mechanism for moving and positioning the recording / reproducing head with respect to a recording medium of a recording / reproducing apparatus. And a carriage arranged to be movable with respect to the recording medium, the carriage having pressing means for pressing the recording / reproducing head against the recording medium, and a supporting member for supporting the pressing means, The access mechanism of the recording / reproducing apparatus is characterized in that the supporting member is formed of a non-magnetic material.

[0010]

According to the present invention, the movable part of the access mechanism is VC
The recording / reproducing apparatus can be provided with a stable access mechanism without receiving an unnecessary force from the leakage magnetic flux line by the magnet of M.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view of a recording / reproducing apparatus incorporating the access mechanism of the present invention, and FIG. 2 is a perspective view of a main part of FIG.

In FIGS. 1 and 2, a disc cassette (not shown) is guided by a cassette holder 12 arranged in a chassis 11 and is mounted therein.
The recording medium 10 is rotatably supported inside the disc cassette. A shutter opening / closing lever 16 for opening / closing a shutter for covering the opening of the cassette holder with respect to the recording medium 10 and for loading / unloading a disk cassette is provided at a corner of the cassette holder 12. A head load assembly 17 is arranged adjacent to a voice coil motor (hereinafter referred to as VCM) 13 in order to bring the magnetic heads 8 and 9 into contact with or away from the recording medium 10. The head load assembly 17 includes a solenoid (not shown). When the solenoid is energized, the magnetic heads 8 and 9 come into contact with the recording surface of the recording medium. When the energization is turned off, the magnetic heads 8 and 9 cause the recording medium 10 to move. Away from the recording surface of.

Next, the magnetic head access mechanism (seek mechanism) will be described. The magnetic head seek mechanism has a VCM 13 as a drive source, and a magnet 19 is provided inside a yoke 18 of this VCM. The coil 20 attached to the carriage 1 is arranged so as to face the magnet 19. When a current flows through the coil 20, the carriage 1 is linearly moved by the interaction between the magnetic field generated in the coil and the magnetic field generated in the magnet 19. That is, the coil 20 and the magnet 19
Constitutes a linear motor, and the carriage 1 is moved by this linear motor.

Further, the carriage 1 has a head arm 3
Are attached together with the spring hook plate 50 with screws 52. The spring hook plate 50 is provided with a pressing spring 51 for pressing the magnetic heads 8 and 9 described later against the recording medium 10. Therefore, the head arm 3 and the pressing spring 52 form a pressing means.

The carriage 1 has a plurality of rollers 2
1 is installed at an arbitrary angle and preload 22
Is composed of a roller 22a and a load spring 22b for pressing the roller 22a against the first guide bar 23 and the second guide bar 24.
The guide bars 23 and 24 are elastically supported between the guide bars 23 and 24 via the rollers 21.
Guided by, the seek can be performed in a direction approaching the center of the recording medium 10 and a direction leaving the center of the recording medium 10 to move to a predetermined track position.

Specifically, the above-mentioned magnetic heads 8 and 9 are attached to the carriage 1 and the head arm 3, and as is well known, information is recorded on both sides of the recording medium by the magnetic heads 8 and 9. , Will be played.

Further, a linear scale 15 is provided in parallel with the guide bars 23 and 24, the linear scale 15 is fixed to the chassis 11, and slits 15a are formed in the linear scale 15 at equal intervals. The sensor 25 attached to the carriage 1 (the sensor 25 and the linear scale 15 compose the encoder 26) moves along the linear scale 15 when the carriage 1 moves linearly. Like the conventional example, the sensor 25 has a light emitting element and a light receiving element (not shown), and the light emitted from this light emitting element is received by the light receiving element through the slit 15a of the linear scale 15, and the sensor 25 Positioning of the sensor (position detecting means) with respect to the linear scale, and thus positioning of the recording heads 8 and 9 with respect to the track of the recording medium 10 is performed by the number of signals generated when light is received by the light receiving element during movement of.

Here, since the spring plate 50 provided in the position close to the VCM 13 is made of a non-magnetic material such as phosphor bronze, it is not affected by the leakage magnetic flux lines of the magnet 19. Absent. Also, the screw 52 is preferably made of a non-magnetic material as well.

Next, the control of the recording / reproducing apparatus incorporating the access mechanism of the present invention will be described with reference to FIG.
In FIG. 5, the moving destinations of the magnetic heads 8 and 9 are determined via an input means (not shown) such as a keyboard or a memory of a microprocessor (not shown), and a moving command is sent from the signal line a to perform addition. Circuit 101, power amplifier 1
The VCM 13 is driven via 02. When the VCM 13 is driven, the current flowing through the coil 20 and the magnet 19
The carriage 1 moves the guide bar 23,
Moved along 24. When the carriage 1 is moved, the sensor 25 provided integrally with the carriage 1 and the linear scale 15 fixed to the chassis 11 act so that information about the movement of the carriage 1 is, for example, two information whose phases are shifted by 90 °. The signals φA and φB are output from the encoder 26. The output signal of the encoder 26 is first input to the operation amplifier 103 in the subsequent stage, and rough positioning of the head position is performed with reference to the intersection of both signal waveforms, that is, the point where the phase difference is zero. The signal b is input to the adding circuit 101 in the subsequent stage.

The output signal of the encoder 26 is input to the comparators 104 and 105 in the subsequent stage and compared with a predetermined value, and the output is input to the track counter 106 in the subsequent stage to count in the forward or reverse direction. The microcomputer 10 outputs the output as a current position signal c indicating which position of the track the head is currently on.
Input to 0.

Further, information on the moving speed of the carriage detected by the electronic tachometer 150 is used as the phase compensation circuit 10.
8 and the phase-compensated signal d is added to the adder circuit 101.
To prevent oscillation due to phase shift. Further, the signal f is the microcomputer 100 for controlling the speed.
Entered in.

Further, the signal relating to the moving speed of the carriage detected by the electronic tachometer 150 is a differentiating circuit 10.
9 and is compared with a predetermined value in the comparator 110 in the subsequent stage. When a speed fluctuation exceeding the reference value of the comparator 110 occurs, the output signal e from the comparator is applied to the microcomputer 100, for example, writing is prohibited to prevent data destruction due to impact.

Further, the servo information of the track recorded on the recording medium 10 is detected by the magnetic heads 8 and 9 itself, amplified by the amplifier 111 in the subsequent stage, input to the position error detection circuit 112, and track-followed. The position error signal g is input to the microcomputer 100.

In this way, the coarse position signal b and the phase-compensated velocity signal d directly input to the adder circuit 101, the current position signal c, the velocity signal f input to the microcomputer 100, and the writing by the velocity fluctuation are written. Accurate position control of the carriage 1 and the magnetic heads 8 and 9 that are moved integrally with the carriage 1 is performed according to the shock prevention signal e and the track-following servo signal g at the time, for example, the count value of the target position in the microcomputer 100 and the sensor. When the count value obtained by the track counter 106 coincides with the movement of 25, the signal a becomes zero, and when the operation amplifier 103 is zero, that is, the head is stopped at the track position corresponding to the predetermined slit position. Become.

In this way, head position control can be performed. At this time, according to the above-described access mechanism of the present invention, the movable portion of the access mechanism does not receive unnecessary force from the leakage magnetic flux line by the magnet of the VCM, and can be a stable access mechanism.

[0026]

As described in detail above, according to the access mechanism of the present invention, the supporting member for supporting the pressing means for pressing the recording / reproducing head arranged on the carriage against the recording medium is made of a non-magnetic material. As a result, the movable portion of the access mechanism does not receive an unnecessary force from the leakage flux line by the magnet of the VCM, and a stable access mechanism can be obtained.

[Brief description of drawings]

FIG. 1 is a plan view of a recording / reproducing apparatus incorporating an access mechanism of the present invention.

FIG. 2 is an enlarged perspective view of a main part of the recording / reproducing apparatus shown in FIG.

FIG. 3 is a block diagram of a head position control circuit.

FIG. 4 is a perspective view of a main part of a conventional device.

FIG. 5 is a perspective view showing magnetic flux lines of a VCM.

[Explanation of symbols]

1 carriage 3 head arm 8 First recording / reproducing head 9 Second recording / reproducing head 13 Voice coil motor 50 Spring plate (support member) 50 Pressing spring (pressing means)

Claims (3)

[Claims] 1. An access mechanism for moving and positioning a recording / reproducing head with respect to a recording medium of a recording / reproducing apparatus, wherein a carriage supporting at least one recording / reproducing head and movably arranged with respect to the recording medium. Have,
The carriage has a pressing means for pressing the recording / reproducing head against a recording medium, and a supporting member for supporting the pressing means, and the supporting member is formed of a non-magnetic material. Access mechanism. 2. The access mechanism of the recording / reproducing apparatus according to claim 1, wherein the carriage has a head arm,
The pressing means is composed of a head arm supporting one of the recording / reproducing heads and a pressing spring applied to the supporting member, and the supporting member is a spring hook plate supporting one end of the pressing spring. Access mechanism of recording / playback device. 3. The access mechanism of the recording / reproducing apparatus according to claim 2, wherein the spring hook plate is made of phosphor bronze.