JPH11242826A - Optical head and recording and/or reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the tilt of an objective lens, to reduce the tilt of an optical axis and to perform high density recording by providing a support shaft erected in the direction nearly parallel to the optical axis of a light beam irradiating on a signal recording surface of a disk like record-medium and a bobbin supporting the objective lens and moving in the direction nearly parallel to the optical axis and in the radial direction of the support shaft along the support shaft. SOLUTION: A biaxial actuator 42 is mainly composed of the bobbin 60 supporting the objective lens 41, a magnetic circuit moving the bobbin 60 in the direction along the optical axis of a laser beam irradiating on a magneto- optical disk 3 of a minidisk 1 and in the radial direction of the magneto-optical disk 3 and the support shaft 80 inserted into the bobbin 60 and guiding the movement of the bobbin 60. Thus, since the bobbin 60 supporting the objective lens 41 is moved along the support shaft 80, when the fitting precision of the support shaft 80 is secured, the tilt precision of the objective lens 41 is kept precisely, and the fall of the optical axis of the laser beam irradiating on the magneto-optical disk 3 is suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical head for irradiating a disk-shaped recording medium accommodated in a disk cartridge with light and receiving light reflected by the disk-shaped recording medium, and this optical head. The present invention relates to a recording and / or reproducing apparatus using the same.

[0002]

2. Description of the Related Art Conventionally, a mini disk (Mini Disk) having a magneto-optical disk having a diameter of 64 mm housed in a cartridge is known.
Discs (trademarks) as recording media have become widespread.

[0003] Opening portions are provided at opposing positions of an upper shell and a lower shell of the mini disk cartridge so that a magneto-optical disk accommodated in the cartridge can be exposed to the outside. The cartridge is provided with a shutter member for opening and closing the opening.

When the mini disc is not loaded in the recording / reproducing apparatus, the opening is closed by the shutter member. When the mini-disc is loaded in the recording / reproducing apparatus, the shutter member is moved by the shutter moving means of the recording / reproducing apparatus to open the opening, and the magneto-optical disc accommodated in the cartridge is moved to the outside. It is made to face.

A recording / reproducing apparatus used in this mini disc system irradiates a laser beam onto a signal recording face of a magneto-optical disc at a position facing one face of a loaded mini disc, and reflects the laser light on the signal recording face. An optical head for receiving the returned light is provided, and a magnetic head for applying an external magnetic field to the signal recording surface of the magneto-optical disk is provided at a position facing the other surface of the mini disk.

When a mini disk is loaded in the recording / reproducing apparatus, the shutter member is moved by the shutter moving means to open the opening, and the magneto optical disk is rotated by the disk rotation drive mechanism.

During recording, the optical head irradiates the signal recording surface of the magneto-optical disk with laser light from one surface side of the mini disk through an opening, and the magnetic head is driven by the other of the mini disk. A magnetic field is applied to the portion of the signal recording surface of the magneto-optical disk irradiated with the laser light from the surface side through the opening.

In a magneto-optical disk, when a predetermined portion of a signal recording surface is irradiated with a laser beam, a portion irradiated with the laser beam is heated to a temperature higher than the Curie temperature and loses coercive force. Then, a magnetic field from the magnetic head is applied to the portion where the holding force has disappeared, and this portion is magnetized according to the direction of the magnetic field. After that, the magnetized part by the relative movement of the laser light drops below the Curie temperature,
An information signal is recorded by fixing the direction of this magnetization.

At the time of reproduction, the optical head
Laser light is applied to the signal recording surface of the magneto-optical disk from one side through which the information signal is recorded, through the opening. Then, for example, the optical head detects this return light by utilizing the Kerr effect in which the polarization plane of the return light reflected on the signal recording surface rotates in different directions depending on the direction of magnetization, thereby reproducing the information signal. Is performed.

In the optical head of the recording / reproducing apparatus, the objective lens is supported by a biaxial actuator. And in this optical head,
Even if the objective lens is moved by the biaxial actuator in the direction (focusing direction) along the optical axis of the laser beam, for example, when the mini-disk that is rotated is caused to run out, for example, Light is always focused on the magneto-optical recording layer. In this optical head, the objective lens is moved by the two-axis actuator in a direction (tracking direction) substantially orthogonal to the optical axis of the laser light, thereby causing, for example, eccentricity or the like in the mini-disc to be rotated. In such a case, the spot of the laser beam always follows the recording track.

A biaxial actuator 100 used in the optical head includes, for example, a fixing portion 101 fixed to a slide base 120 and an objective lens 1 as shown in FIG.
And a bobbin 102 that supports the bobbin 10. The bobbin 102 is attached to the fixed portion 101 via a leaf spring 103.

The bobbin 102 has a tracking coil 1
04 and a focusing coil 105 are provided. On the other hand, a yoke 106 is provided upright on the fixed portion 101, and a magnet 107 is attached to the yoke 106. And the two-axis actuator 10
Numeral 0 moves the objective lens 110 supported by the bobbin 102 in the focusing direction and the tracking direction by an electromagnetic force generated between the tracking coil 104 and the focusing coil 105 and the magnet 107.

[0013]

By the way, with the spread of multimedia in recent years, the amount of information handled at a time has become enormous, and a recording medium for recording such information has a small storage capacity. An increase is desired.

Therefore, a high-density mini-disk system in which the recording capacity of a magneto-optical disk is increased by increasing the recording density of a magneto-optical disk has also been proposed. In this high-density mini-disc system, the recording capacity, which was conventionally 140 Mbytes, has been increased to 650 Mbytes.

In this high-density mini-disk system, as an objective lens for condensing a laser beam, in order to realize an improvement in the recording density of a magneto-optical disk, an objective lens used in the previous mini-disk system is used. The lens has a large numerical aperture. Specifically, while the numerical aperture of the objective lens used in the previous mini-disc system is 0.45, the objective lens with a numerical aperture of 0.52 is used in the high-density mini-disc system. doing.

As described above, when a lens having a large numerical aperture is used as an objective lens, the recording and reproduction are easily affected by the inclination of the optical axis of the laser light, and the laser light for recording and reproduction is permitted. The margin (skew tolerance) of the tilt of the optical axis becomes smaller.

The tilt of the optical axis of the laser beam also depends on the mounting accuracy of each part constituting the optical head, but is caused by the tilt (dynamic skew) of the objective lens during the operation of the biaxial actuator. Often.

For this reason, in the optical head, it is desired to suppress the inclination of the objective lens during the operation of the biaxial actuator. However, the biaxial actuator 100 as described above has a bobbin 10 supporting the objective lens 110.
2 is attached to the fixed portion 101 via the leaf spring 103, so that the objective lens 110 is structurally
There is a limit in suppressing the inclination of

Accordingly, the present invention provides an optical head which realizes high-density recording by suppressing the inclination of the objective lens to reduce the inclination of the optical axis of the laser beam, and a recording and / or reproducing apparatus using the optical head. The purpose is to provide.

[0020]

SUMMARY OF THE INVENTION An optical head according to the present invention has been developed in order to solve the above-mentioned problems.
As a method of moving the objective lens, a so-called shaft sliding type is adopted, and the support shaft and a part of the bobbin supporting the objective lens are arranged so as to face an opening provided on one main surface of the cartridge. I am trying to do it.

That is, an optical head according to the present invention comprises: an objective lens for converging light emitted toward a disk-shaped recording medium and irradiating the light onto a signal recording surface of the disk-shaped recording medium; A support shaft erected in a direction substantially parallel to the optical axis of the light irradiated on the recording surface, the light supporting the objective lens, and irradiated along the support shaft on the signal recording surface of the disk-shaped recording medium. And a bobbin that moves in a direction substantially parallel to the optical axis and in a direction around the axis of the support shaft.

In this optical head, the support shaft and a part of the bobbin face the disk-shaped recording medium accommodated in the cartridge through an opening provided on one main surface of the cartridge, In a state where the other portion faces one main surface of the cartridge, the disc-shaped recording medium is irradiated with light and the light reflected by the disc-shaped recording medium is received.

This optical head supports the bobbin when the focus of the light focused by the objective lens is shifted from the signal recording surface of the disc-shaped recording medium when the disc-shaped recording medium is irradiated with light. It slides along the axis in a direction parallel to the optical axis of the light irradiated on the signal recording surface. Thereby, the objective lens supported by the bobbin moves in the direction along the optical axis of the light, and the light is focused on the signal recording surface of the disk-shaped recording medium.

Also, when irradiating the disk-shaped recording medium with light, if the focal point of the light focused by the objective lens deviates from the recording track of the disk-shaped recording medium, the optical head supports the bobbin. It slides around the support shaft along the shaft. Accordingly, the objective lens supported by the bobbin moves in a direction substantially orthogonal to the optical axis of the light irradiated on the signal recording surface, and the focal point of the light follows the recording track.

Further, the recording and / or reproducing apparatus according to the present invention provides a disk cartridge loading section for loading a disk cartridge containing a disk-shaped recording medium in a cartridge having an opening on one main surface, An optical head for irradiating the disk-shaped recording medium of the disk cartridge loaded in the cartridge loading section with light and receiving light reflected by the disk-shaped recording medium;

In this optical disk apparatus, the optical head converges the light emitted toward the disk-shaped recording medium and irradiates the light onto the signal recording surface of the disk-shaped recording medium; A support shaft erected in a direction substantially parallel to the optical axis of light irradiated on the signal recording surface, supports the objective lens, and is irradiated on the signal recording surface of the disk-shaped recording medium along the support shaft. A bobbin that moves in a direction substantially parallel to the optical axis of light and in a direction around the axis of the support shaft, and the support shaft and a part of the bobbin are inserted into the cartridge via an opening provided on one main surface of the cartridge. While irradiating the disc-shaped recording medium with the other part of the bobbin facing the main surface of the cartridge while facing the disc-shaped recording medium accommodated in the Light It has been made to receive.

[0027]

Embodiments of the present invention will be described below with reference to the drawings.

A recording / reproducing apparatus to which the present invention is applied uses a mini-disc having a magneto-optical disc having a diameter of 64 mm in a cartridge as a recording medium, and records information signals on the magneto-optical disc of the mini-disc. And / or perform reproduction.

As shown in FIGS. 1 and 2, the mini-disc 1 has a diameter of 64 m in a cartridge body 2 which is a housing.
A magneto-optical disk 3 having a thickness of 1.2 mm and a thickness of 1.2 mm is rotatably accommodated.

The cartridge body 2 has a pair of upper and lower shells 4 and 5 butted and joined together, and has a generally rectangular thin box shape as a whole. The length of one side of the cartridge body 2 shown in FIG.
m, the length of the other side shown by B in FIG. 1 is about 72 mm, and the thickness shown by C in FIG. 1 is about 5 mm.

The cartridge body 2 constituted by the upper shell 4
As shown in FIG. 1, a mini disk 1 is loaded into a recording / reproducing apparatus on a top surface 2a of the recording medium, and a recording head for allowing a magnetic head of the recording / reproducing apparatus to enter the cartridge body 2 when a recording operation is performed. Opening 6 is formed.
The recording opening 6 is formed in a substantially rectangular shape, and the length of one side indicated by D in FIG. 1 is approximately 17 mm.
The length of the other side indicated by middle E is about 24 mm.

On the lower surface 2b of the cartridge body 2 constituted by the lower shell 5, the mini disk 1 is loaded into the recording / reproducing apparatus at a position facing the recording opening 6, as shown in FIG. A recording / reproducing opening 7 for irradiating a laser beam from an optical head provided in the recording / reproducing apparatus to the magneto-optical disk 3 in the cartridge body 2 when a recording operation or a reproducing operation is performed is formed. The recording / reproducing opening 7 is formed in a substantially rectangular shape similarly to the recording opening 6, and the length of one side indicated by F in FIG.
7 mm, and the length of the other side indicated by G in FIG.
mm.

A part of the recording / reproducing area of the magneto-optical disk 3 housed in the cartridge body 2 is exposed outward through these openings 6 and 7 in the radial direction.

The cartridge body 2 is provided with a shutter member 8 for opening and closing the openings 6 and 7. The shutter member 8 is formed by, for example, bending a thin metal plate formed by punching, and
A pair of shutter plates 9 and 1 having a size sufficient to cover
0 and a connecting piece 11 connecting the base ends of the shutter plates 9 and 10.

The shutter member 8 has a substantially U-shape as a whole, and is mounted on one side of the cartridge body 2 so that the shutter plates 9 and 10 cover the openings 6 and 7, respectively. The openings 6, 7 are opened and closed by moving along the provided guide grooves.

When the mini-disc 1 is not loaded in the recording / reproducing apparatus, the recording opening 6 and the recording / reproducing opening 7 formed in the cartridge body 2 are closed by the shutter member 8, respectively. Have been. At this time, the shutter member 8 is locked by a lock member (not shown) so as not to move in a direction to open the openings 6 and 7.

When the mini disk 1 is loaded in the recording / reproducing apparatus, the locking of the shutter member 8 by the lock member is released by the unlocking member provided in the recording / reproducing apparatus, and the shutter moving member provided in the recording / reproducing apparatus. When the shutter member 8 is moved, the recording opening 6 and the recording / reproducing opening 7 are opened, so that recording and reproduction can be performed.

In the center of the lower surface 2b of the cartridge body 2, there is formed a circular central opening 12 for allowing a disk table of a disk rotation operation mechanism for rotating the magneto-optical disk 3 to enter the cartridge body 2. Have been.

The magneto-optical disk 3 housed in the cartridge body 2 is formed by sequentially forming a magneto-optical recording film, a reflective film, and a protective film on a disc-shaped polycarbonate substrate having a diameter of 64 mm. Is 1.2 mm. The magneto-optical recording film has a magneto-optical recording layer sandwiched between dielectric layers, and the magneto-optical recording layer constitutes the signal recording surface described above.

The magneto-optical disk 3 is irradiated with laser light from the optical head from the polycarbonate substrate side, and a magnetic field from the magnetic head is applied from the protective film side. The information signal is recorded in the. The recording capacity of the magneto-optical disk 3 is 650 Mbytes.

A center hole 13 is formed in the center of the magneto-optical disk 3, and a hub 14 is attached so as to close the center hole 13. This hub 14
Is made of a metal material having magnetism that allows a magnet provided on a disk table to be attracted. The center hole 13 and the hub 14 are formed in a central opening 12 provided in the center of the lower surface 2 b of the cartridge body 2.
Has been exposed to the outside.

The mini disk 1 constructed as described above
Is inserted into and removed from the recording / reproducing device with one side surface orthogonal to the direction in which the shutter member 8 moves as an insertion end.
That is, the mini-disc 1 is indicated by X in the arrows in FIGS.
_1, it is inserted and removed X ₂ direction to the recording and reproducing apparatus as inserting and removing direction.

FIG. 3 shows the internal configuration of a recording / reproducing apparatus 20 using the mini-disc 1 configured as described above as a recording medium. The recording / reproducing apparatus 20 has a cartridge loading unit 2 on an upper surface side in a housing (not shown) constituting a main body of the apparatus.
A chassis 22 designated as 1 is provided.

The chassis 22 is formed of a metal material into a flat rectangular shape, and has a size slightly larger than the outer dimensions of the main surface of the mini disc 1. A cartridge holder 23 for holding the mini-disc 1 and loading and unloading the mini-disc 1 into and from the cartridge loading section 21 is rotatably attached to the chassis 22.

An optical head 24 for irradiating light to the magneto-optical disk 3 of the mini disk 1 loaded in the cartridge loading section 21 is movably supported on the chassis 22 and connected to the optical head 24. A magnetic head 25 for applying a magnetic field to the magneto-optical disc 3 of the mini disc 1 loaded in the cartridge loading section 21 is provided.

Further, a disk rotation operation mechanism 26 for rotating the magneto-optical disk 3 of the mini disk 1 loaded in the cartridge loading section 21 is attached to the chassis 22.

As described above, the recording / reproducing apparatus 20 is mounted on the chassis 22 having the cartridge loading section 21 on the upper surface side.
The recording / reproducing unit is configured by attaching the disk rotation operation mechanism 26, the optical head 24, and the magnetic head 25, respectively.

A disk rotation operating mechanism 26 attached to a substantially central portion of the chassis 22 has a drive motor (not shown) provided on the lower surface of the chassis 21 and a drive shaft 27 of the drive motor. And a disk table 28 disposed in the storage area.

The disk table 28 is formed in a disk shape as a whole, and has a magnet disposed therein. When the mini disk 1 is loaded in the cartridge loading section 20, the disk table 28 magnetically attracts the hub 14 attached to the center of the magneto-optical disk 3 so that the magneto-optical disk 3 rotates the drive motor. The magneto-optical disk 3 is clamped so as to rotate with the rotation.

The chassis 22 is provided with an optical head opening 29 at a position adjacent to the disk rotation operation mechanism 26 so that the optical head 24 attached to the lower surface of the chassis 22 faces the upper surface of the chassis 22. Have been.
When the mini disc 1 is loaded into the cartridge loading section 21, the optical head opening 29 is
Is formed in a size corresponding to the moving area of the optical head 24 so that the optical head 24 can move over the inner and outer peripheries of the magneto-optical disk 3 facing the outside of the cartridge body 2 through the recording / reproducing opening 7. I have.

A pair of support pieces 30a, which rotatably support a cartridge holder 23 holding the mini-disc 1, are provided on both sides on the rear side of the chassis 22 opposite to the front side on which the mini-disc 1 is inserted. 30b is provided. The cartridge holder 23 is attached to the chassis 22 via the support pieces 30a and 30b.

The cartridge holder 23 has a top plate 31
And a pair of cartridge holding portions 32a and 32b formed by folding on both sides of the top plate portion 31. When the mini-disc 1 is inserted into the cartridge holder 23 through an insertion opening 23a provided on the front side of the cartridge holder 23, one side surface and a side surface parallel to the side surface form a pair of cartridge holding members. It is held by the parts 32 a and 32 b and is housed in the cartridge holder 23.

On the side surface of one of the cartridge holders 32b of the cartridge holder 23, a lock release member 33 for releasing the above-mentioned lock member for restricting the movement of the shutter member 8 of the mini disc 1 is provided. It protrudes inward. Further, a shutter moving member 34 which engages with the shutter member 8 to move the shutter member 8 is provided on the side surface of one of the cartridge holding portions 32b of the cartridge holder 23 so as to project inward of the cartridge holder 23. Has been established.

When the mini-disc 1 is inserted into the cartridge holder 23, first, the unlocking member 33 enters the above-mentioned guide groove provided on one side surface of the mini-disc 1. Then, the lock release member 33 releases the state in which the shutter member 8 is locked by the lock member by pressing the lock member.

On the other hand, when the mini-disc 1 is inserted into the cartridge holder 23, the shutter moving member 34 is inserted into an engaging hole provided in the connecting piece 11 of the shutter member 8, and is engaged with the shutter member 8. You. In this state, when the mini disc 1 is further pushed into the cartridge holder 23, the shutter member 8 engaged with the shutter moving member 34 is moved, and the recording opening 6 of the mini disc 1 is moved.
In addition, the recording / reproducing opening 7 is opened.

In the cartridge holder 23, a window 35 is formed in the top plate 31 so as to allow the head chip of the magnetic head 25 to enter the cartridge holder 23.

The cartridge holder 23 is provided with a magnetic head elevating mechanism 36 for moving the magnetic head 25 in the direction of moving toward and away from the magneto-optical disk 3 of the mini disk 1 housed in the cartridge holder 23. ing.

The elevating operation mechanism 36 includes a magnetic head 25.
, A magnetic head elevating plate 37 for rotating the magnetic head 25 and an operation member 38 for moving the magnetic head elevating plate 37 by a moving mechanism (not shown).

The magnetic head elevating plate 37 is extended over the window 35 so that the top plate 3
1. On the other hand, an operation member 38 for rotating the magnetic head elevating plate 37 is movably disposed on the top plate 31 of the cartridge holder 23. On one side of the operating member 38, the operating member 38, when moving the driven with arrows in FIG. 3 B ₁ direction or B ₂ direction by the driving mechanism, operated to rotate the magnetic head lifting plate 37 cams Piece 3
9 is formed so as to rise upward.

[0060] elevation operating mechanism 36, the operating member 38, the upper top plate portion 31 of the cartridge holder 23 by the drive mechanism, by being moved in arrow in FIG B ₁ direction, the magnetic head lifting plate 37 is a cam piece It rotates in the direction of descending along 39.

Thus, the head chip of the magnetic head 25 abutting on the magnetic head elevating plate 37 is housed in the cartridge holder 23 through the window 35 opened in the top plate 31 of the cartridge holder 23. The mini disk 1 moves in a direction approaching the magneto-optical disk 3.

The lifting operation mechanism 36 includes an operation member 38.
Is driven by the top plate 3 of the cartridge holder 23.
Over 1, by being moved in arrow in FIG B ₂ direction,
The magnetic head elevating plate 37 is pushed up by the cam piece 39.

As a result, the head chip of the magnetic head 25 abutting on the magnetic head elevating plate 37 moves in the direction away from the magneto-optical disk 3 of the mini disk 1 accommodated in the cartridge holder 23.

[0064] Cartridge holder 23 constructed in this way, in FIG. 3 arrow Y ₁ direction of the cartridge loading section 21
The mini-disc 1 is inserted and removed in a state where the mini-disc 1 is pivoted upward away from the disc. Then, the cartridge holder 23 holds the mini-disc 1, when it is rotated downward diagrams 3 of arrow Y ₂ direction of the cartridge loading section 21 side, holding the mini-disc 1 cartridge loading was 2
Attach to 1.

The optical head 24 movably attached to the chassis 22 has a slide base 40 formed by die-casting a metal material such as zinc. The optical head 24 converges a semiconductor laser (not shown) and laser light emitted from the semiconductor laser and places the laser beam on the signal recording surface of the magneto-optical disk 3 of the mini disk 1 loaded in the cartridge loading section 21. The objective lens 41 to be illuminated, an optical element such as a light receiving element (not shown) for receiving return light reflected on the signal recording surface of the magneto-optical disk 3, and the light of the light illuminating the objective lens 41 to the magneto-optical disk 3 A biaxial actuator 42 for moving in a direction along the axis and in a radial direction of the magneto-optical disk 3 is attached to the slide base 40. The details of the biaxial actuator 42 will be described later.

The optical head 24 transmits the laser beam emitted from the semiconductor laser via the optical element such as the objective lens 29 to the signal recording surface of the magneto-optical disk 3 of the mini disk 1 loaded in the cartridge loading section 21. It is configured to converge and irradiate it on the top. Also, this optical head 2
Numeral 4 is configured to receive return light of the light beam irradiated on the signal recording surface of the magneto-optical disk 3 and to read out information signals recorded on the magneto-optical disk 3.

The optical head 24 detects a focus error signal and a tracking error signal from the return light reflected on the signal recording surface of the magneto-optical disk 3, and drives the biaxial actuator 42 according to the error signals. By moving the objective lens 41 to the magneto-optical disk 3
Are moved in the direction along the optical axis of the light applied to the optical disk and in the radial direction of the magneto-optical disk 3 to perform focusing control and tracking control.

In particular, in the optical head 24, the magneto-optical disk 3 of the mini disk 1 for irradiating a laser beam is used.
Is a high-density recording disk having a recording capacity of 650 Mbytes. Therefore, a lens having a high numerical aperture of 0.52 is used as the objective lens 41.

The optical head 24 configured as described above
Are movably attached to the chassis 22 via a pair of guide shafts 43 attached to the lower surface of the chassis 22 in parallel with each other. The optical head 24 is guided by a guide shaft 43 via an optical head feed mechanism driven by a feed motor (not shown) attached to the lower surface side of the chassis 22, and is mounted on the cartridge loading section 21. The disk 1 is fed in the radial direction of the magneto-optical disk 3.

The feed motor for driving the optical head feed mechanism has a drive gear (not shown) attached to its drive shaft. The drive gear is meshed with a reduction transmission gear (not shown) constituting the optical head feed mechanism. The reduction gear is meshed with a driven gear 45 mounted on one end of a screw shaft 44 rotatably mounted in parallel with the guide shaft 43, and moves the screw shaft 44 through the driven gear 45 in a direction around the axis. Rotate.

The optical head 24 is engaged with the screw shaft 44 via an engaging pin. When the feed motor is driven to rotate the screw shaft 44, the cartridge is loaded along the guide shaft 43. The mini disc 1 loaded in the unit 21 is moved in the radial direction of the magneto-optical disc 3.

The magnetic head 25 is connected to the optical head 24 via a substantially L-shaped connecting member 46, and is arranged so as to move in synchronization with the optical head 24.

The magnetic head 24 has a rotation support plate 47 rotatably attached to a connecting member 46 connected to the optical head 24, and a base end side supported on the distal end side of the rotation support plate 47. And a slider 4 attached to the tip end of the head chip support plate 48.
9 and a head chip 50 attached to the slider 49 are configured as main constituent members.

The magnetic head 25 is mounted on the rotation support plate 4.
The base end of 7 is rotatably supported by the connecting member 46 in a cantilever state.

The connecting member 46 has a lower end portion at the optical head 24.
And the upper end extends to the upper part of the cartridge holder 23 along the rear end of the chassis. The connecting member 46 is provided at its upper end portion with a rotation support plate 47 that constitutes the magnetic head 25.
Is rotatably supported.

The rotation support plate 47 is formed of a rigid metal plate or the like, and is urged to rotate toward the cartridge loading section 21 by a torsion spring (not shown).

The head chip support plate 48 for supporting the slider 49 is formed in a long shape by a thin metal plate having elasticity, and is attached so that the base end thereof is overlapped with the rotation support plate 47. The head support plate 48
Has a slider 49 attached to its tip end side.

The slider 49 is formed of a synthetic resin material having good slidability and abrasion resistance into a bottomed cylindrical shape.
The head chip 50 is housed inside. An opening is provided in the bottom surface of the slider 49 so that the head chip 50 faces the outside. A magnetic field generated by the head chip 50 is applied to the magneto-optical disk 3 of the mini disk 1 through this opening. It has been made.

The slider 49 is provided with a disk sliding portion on the bottom surface, and the disk sliding portion slides on the rotating magneto-optical disk 3 during recording.

The head chip 50 has, for example, a magnetic core formed of a magnetic material such as ferrite attached to a bobbin around which a coil is wound. The head chip 50 generates a magnetic field according to the supplied power when power is supplied to the coil from an external circuit.

The magnetic head 25 configured as described above
Is attached to the connecting member 46, and the cartridge holder 23 is inserted from above the cartridge holder 23 through the window 35.
It is arranged to face the inside. Then, the magnetic head 25
The head chip 50 is opened in the top plate portion 31 of the cartridge holder 23 by rotating the head chip supporting plate 48 in contact with the magnetic head elevating plate 37 and rotating the magnetic head elevating plate 37. The mini disk 1 accommodated in the cartridge holder 23 moves toward and away from the magneto-optical disk 3 through the window 35.

Although not shown, the housing constituting the main body of the recording / reproducing apparatus 20 includes, for example, a power-on button for driving the recording / reproducing apparatus, a recording button for selecting various operation modes, a reproduction button, A key input unit such as a pause button, a stop button, a volume control button, an eject button, and a display unit for displaying an address of an information signal being reproduced are provided. And the key signal input unit and the display unit configured in this way
CPU (central processing unit) installed in the housing
Is controlled by

The CPU operates the optical head 24 and the magnetic head 2 based on a signal from the key signal input unit.
5. Control the recording / reproducing unit including the disk rotation operation mechanism 26 and the like. The portion of the outer casing where the cartridge holder 23 is provided is rotated as the cartridge holder 23 is rotated, and is configured as a lid for mounting the mini disc 1.

In the recording / reproducing apparatus 20 configured as described above, the objective lens 4 of the optical head 24
4 and 5 as a two-axis actuator for driving
The so-called shaft sliding type biaxial actuator 42 shown in FIG.

The biaxial actuator 42 includes a bobbin 60 for supporting the objective lens 41, a direction along the optical axis of the laser beam applied to the magneto-optical disc 3 of the mini disc 1, and a direction along the magneto-optical disc 3. The main components are a magnetic circuit 70 for moving the bobbin 60 in the radial direction and a support shaft 80 that is inserted into the bobbin 60 and guides the movement of the bobbin 60.

The two-axis actuator 42 is
The slide base 40 is housed in an actuator housing recess 40 a provided substantially at the center.

This shaft sliding type biaxial actuator 42
Since the bobbin 60 supporting the objective lens 41 moves along the support shaft 80, basically, if the mounting accuracy of the support shaft 80 is secured, the inclination accuracy of the objective lens 41 can be maintained with high accuracy. As a result, the tilt of the optical axis of the laser beam applied to the magneto-optical disk 3 can be suppressed.

In particular, the recording / reproducing apparatus 20 has a recording capacity of 6
Magneto-optical disk 3 having a high recording density of 50 Mbytes
The objective lens 41 has a high numerical aperture of 0.52 as the objective lens 41, so that the influence of the tilt of the optical axis of the laser beam can be reduced. Easy to receive.

Therefore, in the recording / reproducing apparatus 20, as a two-axis actuator for driving the objective lens 41, an axis sliding type two-axis actuator 42 for which it is easy to secure optical axis accuracy.
, So that appropriate recording and reproduction can be performed.

In general, even in a shaft sliding type biaxial actuator, a gap must be present between the bobbin and the support shaft in order to slide the bobbin relative to the support shaft. The gap slightly tilts the bobbin with respect to the support shaft, and tilts the objective lens supported by the bobbin. If the size of the gap between the bobbin and the support shaft is the same, the amount of inclination of the objective lens is the same as that shown in FIGS.
As shown in (B), it depends on the length of the portion (sleeve portion) that slides on the spindle of the bobbin.

That is, when the size of the gap between the bobbin and the support shaft is the same, as shown in FIG. 6A, the objective lens generated by the biaxial actuator having the relatively short length L1 of the sleeve portion of the bobbin. As shown in FIG. 6B, the inclination amount R1 of the objective lens caused by the biaxial actuator having a relatively long length L2 of the sleeve portion of the bobbin is obtained.
It is larger than two.

Therefore, in the shaft-sliding type biaxial actuator, in order to further suppress the inclination of the optical axis of the laser beam, it is desirable to increase the length of the support shaft and the sleeve portion of the bobbin. .

Therefore, in the biaxial actuator 42, the periphery of the sleeve of the bobbin 60 and the support shaft 80 are opposed to the recording / reproducing opening 6 of the mini-disc 1, so that the length of the support shaft 80 can be secured. At the same time, by increasing the length of the sleeve portion of the bobbin 60, the inclination of the bobbin 60 is further suppressed, and the inclination of the optical axis of the laser beam is minimized.

Hereinafter, the biaxial actuator 42 will be described in detail.

A focus drive yoke and a tracking drive yoke are provided on the bottom surface of the actuator accommodating recess 40a of the slide base 40 via a skew seat 51 for absorbing a tilt when the biaxial actuator 42 is mounted on the slide base 40. A yoke plate 71 constituting a yoke is provided.

The yoke plate 71 is made of a magnetic material.
From the four edges of the flat bottom plate portion 71a, the first to fourth
Side plate portions 71b, 71c, 71d, 71e are formed to rise. The yoke plate 71 is formed by a first mounting portion 72a extending from the bottom plate portion 71a and a second mounting portion 72b extending from the first side plate portion 71b.
It is attached to the slide base 40.

Further, the bottom plate portion 71a of the yoke plate 71 has
A bearing hole 73 through which the base end portion 80a of the support shaft 80 is inserted is provided at a substantially central portion thereof.

The first side plate portion 71b and the third side plate portion 71d of the yoke plate 71 are erected substantially perpendicularly to the bottom plate portion 71a of the yoke plate 71, and one main surface thereof is opposed to each other. It has been made to be. And this first
The side plate portion 71b and the third side plate portion 71d constitute a focus drive yoke.

A focus driving magnet 74 is attached to the opposing surfaces of the first side plate 71b and the third side plate 71d.

The focus driving magnet 74 is
The mounting surface attached to the side plate portion 71b or the third side plate portion 71d and the two main surfaces parallel to the mounting surface have a substantially square flat plate shape, and these two main surfaces are bisected. It is magnetized to have polarity. The direction of magnetization of both main surfaces of the focus driving magnet 74 is determined by the first side plate 71 b and the third side plate 7.
The first side plate 71b and the third side plate 71d are attached to the opposing surfaces of the first side plate 71b and the third side plate 71d so as to be parallel to the direction in which 1d is erected.

The second side plate portion 71c of the yoke plate 71
And the fourth side plate 71 e is a bottom plate 71 of the yoke plate 71.
The first and second main surfaces are substantially perpendicular to each other, and one main surface of each of them is opposed to each other. The second side plate 71c and the fourth side plate 71e constitute a tracking drive yoke.

A tracking drive magnet 75 is attached to the opposing surfaces of the second side plate 71c and the fourth side plate 71e.

The tracking drive magnet 75 has the same configuration as the focus drive magnet 74, and has a mounting surface mounted on the second side plate 71c or the fourth side plate 71e and a surface parallel to the mounting surface. Both main surfaces have a substantially square plate shape, and are magnetized so that these two main surfaces have bisecting polarities. The tracking drive magnet 75
Is such that the directions of magnetization of both main surfaces are orthogonal to the direction in which the second side plate 71c and the fourth side plate 71e are erected.
The second side plate 71c and the fourth side plate 71e are attached to respective opposing surfaces.

The support shaft 80 has a base end portion 80a whose yoke plate 71
Of the mini disk 1 of the mini disk 1 loaded in the cartridge loading section 21 by being inserted into the bearing hole 73 provided in the bottom plate 71a of the mini disk 1 in the direction substantially perpendicular to the bottom plate 71a of the yoke plate 71. It is erected on the slide base 40 so as to be parallel to the irradiated laser beam.

The support shaft 80 is provided at the tip end 80 thereof.
b is provided so as to face the recording / reproducing opening 6 of the mini disc 1 loaded in the cartridge loading section 21 and to slightly enter the inside of the cartridge main body 2 from the recording / reproducing opening 6.

The bobbin 60 supporting the objective lens 41 is
It is formed of a synthetic resin material or the like, and has a base 61 and an objective lens holder 62 extending from the base 61. The bobbin 60 is movably attached to the slide base 40 via a suspension mechanism (not shown).

The base 61 has a support shaft 80 substantially at the center thereof.
Is inserted from the upper surface 61a to the bottom surface 61b.
Is formed so as to penetrate through. A first annular convex portion 64 protrudes from the upper surface 61 a of the base 61 around the opening end of the through hole 63.

The first annular projection 64 has its center hole 64a aligned with the through hole 63, and the recording / reproducing opening 7 of the mini disc 1 loaded in the cartridge loading section 21.
Is provided on the upper surface 61a of the base 61 so as to face the upper surface 61a.

Further, a second annular convex portion 65 protrudes from the bottom surface 61b of the base portion 61 around the opening end of the through hole 63. The second annular convex portion 65 is provided on the bottom surface 61 b of the base 61 with its center hole 65 a aligned with the through hole 63.

The support shaft 80 has a through hole 63 provided in the base 61, a center hole 64 a of the first annular convex portion 64, and a second
Is inserted over the center hole 65a of the annular convex portion 65. Therefore, in the bobbin 60, the peripheral portion of the through hole 63, the first annular convex portion 64, and the second annular convex portion 65 slide on the support shaft 80, that is, the sleeve portion. Is configured.

In the biaxial actuator 42, the sleeve portion of the support shaft 80 and the bobbin 60 and the peripheral portion thereof face the recording / reproducing opening 7 of the mini disc 1 loaded in the cartridge loading portion 21. Has been made. Therefore, in the biaxial actuator 42, the thickness of the support shaft 80 can be increased without increasing the thickness of the bobbin 60.
And the length of the sleeve portion of the bobbin 60 can be increased, and the inclination of the objective lens 41 can be suppressed.

The base portion 61 has first to fourth side face portions 61c, 61d, 61
e and 61f are provided respectively. Among the first to fourth side surfaces 61c, 61d, 61e, and 61f, the first side surface 61c and the third side surface 61e are parallel to each other, and the second side surface 61d and the fourth side surface 61d. Side part 61 of
f are parallel to each other.

The first to fourth side surfaces 61c, 61
Projections 66 for attaching the focus driving coil 76 or the tracking driving coil 77 are provided at substantially the center of each of d, 61e, and 61f.

A focus drive coil 76 is mounted on the first side surface 61c and the third side surface 61e with the respective protrusions 66 as mounting portions. In addition, the second side surface portion 61d and the fourth side surface portion 61f
, A tracking drive coil 77 is attached using the projections 66 as attachment portions.

In the two-axis actuator 42, the focus driving yoke, the focus driving magnet 74 and the focus driving coil 7 attached to the yoke are used.
6. A magnetic circuit 70 is constituted by the tracking driving yoke, the tracking driving magnet 75 and the tracking driving coil 77 attached to the yoke.

The base 61 has a connection terminal 78 for connecting a focus driving coil 76 and a tracking driving coil 77 to a driving source (not shown) for supplying driving power near the sleeve on the upper surface 61a. Is provided. The focus drive coil 76 and the tracking drive coil 77 are connected to the drive source via a flexible wiring board 79 having one end connected to the connection terminal portion 78 and the other end connected to the drive source. .

The flexible wiring board 79 is connected to the connection terminal portion 78 by soldering one end of the flexible wiring board 79 to the connection terminal portion 78 or the like.

In the two-axis actuator 42,
The connection terminal portion 78 is provided in the vicinity of the sleeve portion of the bobbin 60 and faces the recording / reproducing opening 7 of the mini disc 1.
Inconvenience such as collision with the cartridge body 2 does not occur.

The base 61 of the bobbin 60 has its upper surface 61a side covered with a cover member 90. In the cover member 90, a through-hole 91 having a diameter slightly larger than the first annular convex portion 64 provided on the base 61 of the bobbin 60 is formed in the main surface portion 90a. The annular convex portion 64 and the distal end of the support shaft 80 inserted into the first annular convex portion 64 protrude toward the mini disc 1 through the through hole 91. 4, illustration of the cover member 90 is omitted.

The objective lens holding portion 62 is provided on the second side surface portion 6.
1d and the third side surface portion 61e, the base portion 61
It is extended from. The objective lens holder 62 includes:
A housing recess 6 for housing the objective lens 41 is provided substantially in the center thereof.
7 are provided. Then, the outer edge of the objective lens 41 is held by the peripheral wall of the housing recess 67,
The objective lens 41 is supported by the bobbin 60.

Further, the objective lens holding section 62 includes:
A transmission hole 68 that penetrates from the bottom surface of the housing recess 67 in the thickness direction and transmits laser light reflected by the folding mirror and traveling toward the magneto-optical disk 3 is formed.

The base 61 has a first side surface 61c.
A balancer 69 for maintaining the parallelism of the bobbin 60 is attached between the bobbin 60 and the fourth side surface portion 61f. The balancer 69 prevents the bobbin 60 from tilting toward the objective lens holding unit 62 by attaching the objective lens 41 to the objective lens holding unit 62.
A predetermined weight is added to the side of the bobbin 60 opposite to the side on which the objective lens holding portion 62 is provided, so that the weight balance of the bobbin 60 is maintained with the through hole 63 as a fulcrum.

The biaxial actuator 42 constructed as described above is driven by a driving source (not shown) from the flexible wiring board 7.
9, when a drive current is supplied to the focus drive coil 76 via the coil 9, an electromagnetic force acts between the focus drive coil 76, the focus drive yoke, and the focus servo magnet 74, and the current supplied to the bobbin 60. Along the support shaft 80 in a direction parallel to the optical axis of the laser beam applied to the magneto-optical disk 3 of the mini disk 1. Accordingly, the objective lens 41 supported by the bobbin 60 is moved in a direction parallel to the optical axis of the laser beam applied to the magneto-optical disc 3 of the mini disc 1, that is, in a direction in which the objective lens 41 comes into contact with and separates from the magneto-optical disc 3. Then, focus control is performed.

At this time, the biaxial actuator 42
Since the length of the sleeve portion of the support shaft 80 and the bobbin 60 is set to be long, the bobbin 60 does not greatly tilt with respect to the support shaft 80, and the tilt of the objective lens 41 is suppressed.

When a drive current is supplied from a drive source (not shown) to the tracking drive coil 77 via the flexible wiring board 79, the biaxial actuator 42 is driven by the tracking drive coil 77, the tracking drive yoke, and the tracking drive. An electromagnetic force acts between the driving magnet 75 and the bobbin 60 to slide in the direction around the support shaft 80 in accordance with the magnitude of the supplied current. Thus, the objective lens 41 supported by the bobbin 60 is moved in the direction orthogonal to the optical axis of the laser beam applied to the magneto-optical disc 3 of the mini disc 1, that is, in the radial direction of the magneto-optical disc 3, and the tracking is performed. Control is performed.

At this time, the biaxial actuator 42
Since the lengths of the sleeve portions of the support shaft 80 and the bobbin 60 are set to be long, the bobbin 60 does not greatly tilt with respect to the support shaft 80 as in the case of the focus control. Is suppressed.

The recording / reproducing apparatus 20 includes such a biaxial actuator 42, uses the magneto-optical disk 3 having a high recording density as a recording medium, and uses the objective lens 41.
Even if the requirement for the tilt of the optical axis becomes severe due to the increase in the numerical aperture of the optical disk, the requirement can be sufficiently satisfied and the recording and reproduction can be performed appropriately.

Next, the operation of the recording / reproducing apparatus 20 will be described.

When the recording / reproducing apparatus 20 is set to the recording mode after the mini disc 1 is mounted on the cartridge loading section 21 in the casing of the recording / reproducing apparatus 20, an optical head feed mechanism driven by a feed motor (not shown). Through
The optical head 24 is guided by the guide shaft 43,
The mini disc 1 loaded in the cartridge loading section 21 is fed in the radial direction of the magneto-optical disc 3.

When the optical head 24 is moved to a predetermined position, a laser beam is emitted from the semiconductor laser under the control of a control unit (not shown). The laser light emitted from the semiconductor laser enters the objective lens 41 via the optical element provided in the optical head 24 and is collected by the objective lens 41. The laser light condensed by the objective lens 41 is applied to the recording / reproducing opening 7 of the mini disc 1.
And enters the cartridge main body 2 via the optical disk and irradiates the signal recording surface of the magneto-optical disk 4.

Further, as the optical head 24 moves in the radial direction of the magneto-optical disk 3 of the mini disk 1,
Magnetic head 25 integrated with optical head 24
Moves in the radial direction of the magneto-optical disk 3.

[0132] When the magnetic head 25 is sent operated to a predetermined position, the operating member 38 by the drive motor (not shown) is moved in the arrow B ₁ direction in FIG. 3, the magnetic head lifting plate 37 is rotated I do. As a result, the magnetic head 25 mounted on the magnetic head elevating plate 37 rotates in a direction approaching the magneto-optical disk 3 of the mini disk 1, and the head chip 50 moves the recording opening 6 of the mini disk 1. And enters the cartridge body 2 through the main body.

When the laser beam from the optical head 24 is irradiated on the signal recording surface of the magneto-optical disk 3 of the mini-disc 1, the portion irradiated with the laser beam is heated to a temperature higher than the Curie temperature to increase the coercive force. lose. Then, an external magnetic field modulated by a magnetic field according to the information signal is applied by the magnetic head 24 to the portion where the holding power has been lost.

The magneto-optical disk 3 of the mini disk 1 is rotated by the drive of the disk rotation operation mechanism 26, and the laser light relatively moves, so that the location where the external magnetic field is applied falls below the Curie temperature. The information signal is recorded on the signal recording surface by fixing the direction of the magnetization.

The return light reflected on the signal recording surface of the magneto-optical disk 3 is received by a light receiving element via an optical element provided in the optical head 24, and is converted into an electric signal by the light receiving element. .

The recording / reproducing apparatus 20 generates control signals such as a focus error signal and a tracking error signal from the electric signal supplied from the light receiving element, and drives the biaxial actuator 42 based on these control signals to perform the focus control. And performs tracking control.

When the recording / reproducing apparatus 20 is set to the reproducing mode, the optical head 24 is guided by the guide shaft 43 via an optical head feed mechanism driven by a feed motor (not shown), and The mini disk 1 loaded in the disk 21 is fed in the radial direction of the magneto-optical disk 3.

When the optical head 24 is moved to a predetermined position, a laser beam is emitted from the semiconductor laser under the control of a control unit (not shown). The laser light emitted from the semiconductor laser enters the objective lens 41 via the optical element provided in the optical head 24 and is collected by the objective lens 41. The laser light condensed by the objective lens 41 is applied to the recording / reproducing opening 7 of the mini disc 1.
Through the cartridge body 2 and irradiates the signal recording surface of the magneto-optical disk 3 on which the information signal is recorded.

The return light reflected on the signal recording surface of the magneto-optical disk 3 on which the information signal is recorded has its polarization plane rotated in different directions depending on the direction of magnetization of the signal recording plane.

By detecting the return light, the recording / reproducing apparatus 20 determines the direction of magnetization of the signal recording surface of the magneto-optical disk and reads the information signal.

That is, the return light reflected on the signal recording surface of the magneto-optical disk 3 is blocked by the optical element of the optical head 24 according to the rotation angle of the polarization plane.
Alternatively, the light passes through the optical element and is received by the light receiving element. The return light received by the light receiving element is converted into an electric signal by the light receiving element.

The recording / reproducing apparatus 20 generates a reproduction signal and a control signal from the electric signal supplied from the light receiving element. Then, the recording / reproducing device 20 outputs a reproduction signal and drives the biaxial actuator 42 based on the control signal to perform focus control and tracking control.

As described above, the recording / reproducing device 20
In the optical head 24, a shaft sliding type biaxial actuator 42 is provided, and a support shaft 80 of the biaxial actuator 42, a sleeve portion of the bobbin 60 and a peripheral portion thereof are formed with the recording / reproducing opening 7 of the mini disk 1. Since the lengths of the sleeve portions of the support shaft 80 and the bobbin 60 are set to be long, the bobbin 60 does not greatly tilt with respect to the support shaft 80 during focus control or tracking control.
1 is suppressed.

Therefore, the recording / reproducing apparatus 20 uses the magneto-optical disk 3 having a high recording density as a recording medium, and increases the numerical aperture of the objective lens 41. This request can be sufficiently satisfied and recording and reproduction can be performed appropriately.

The recording / reproducing apparatus 20 using the mini disc 1 in which the magneto-optical disc 3 is housed in the cartridge main body 2 as a recording medium has been described above.
The present invention is not limited to this example, and can be applied to a recording / reproducing apparatus using a disc cartridge in which a read-only optical disc or a phase-change optical disc is housed in a cartridge as a recording medium. .

In the above, the recording / reproducing apparatus 20 for recording and reproducing information signals on and from the magneto-optical disk 3 of the mini disk 1 has been described. However, the present invention is not limited to this example. Instead, the present invention can be applied to a reproducing apparatus that only reproduces information signals or a recording apparatus that only records information signals.

[0147]

According to the present invention, there is provided an optical head comprising: a support shaft erected in a direction substantially parallel to an optical axis of light irradiated on a signal recording surface of a disk-shaped recording medium; and a bobbin for supporting an objective lens. With a portion of the cartridge facing the disc-shaped recording medium accommodated in the cartridge via an opening provided on one main surface of the cartridge accommodating the disc-shaped recording medium,
Since the disc-shaped recording medium is irradiated with light and the light reflected on the disc-shaped recording medium is received, the length of the portion that slides on the support shaft and the support shaft of the bobbin can be reduced. The length can be increased, the inclination of the objective lens can be suppressed, and the tilt of the optical axis of the light applied to the disk-shaped recording medium can be suppressed.

In the recording and / or reproducing apparatus according to the present invention, as an optical head, a support shaft erected in a direction substantially parallel to an optical axis of light irradiated on a signal recording surface of a disk-shaped recording medium. And a part of the bobbin supporting the objective lens is opposed to the disc-shaped recording medium accommodated in the cartridge through an opening provided on one main surface of the cartridge accommodating the disc-shaped recording medium. Since the optical head irradiates the disk-shaped recording medium with light and receives the light reflected by the disk-shaped recording medium, the optical head and the bobbin support the optical head. The length of the portion that slides on the recording medium can be increased, the inclination of the objective lens can be suppressed, and the tilt of the optical axis of the light applied to the disk-shaped recording medium can be suppressed.

Therefore, in this recording and / or reproducing apparatus, a disk-shaped recording medium having a high recording density is used as a recording medium, and the numerical aperture of the objective lens is increased. Even if
This request can be sufficiently satisfied and recording and reproduction can be performed appropriately.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an upper surface side of a mini disk.

FIG. 2 is a perspective view showing a lower surface side of the mini disc.

FIG. 3 is an exploded perspective view of the recording / reproducing apparatus.

FIG. 4 is a plan view of a biaxial actuator.

FIG. 5 is a sectional view taken along line AA in FIG.

6A and 6B are diagrams illustrating a relationship between the length of a sleeve portion and the amount of inclination of an objective lens, wherein FIG. 6A is a cross-sectional view of a biaxial actuator having a relatively short sleeve portion, and FIG. It is sectional drawing of the biaxial actuator whose length of a sleeve part is comparatively long.

FIG. 7 is a plan view of a conventional two-axis actuator.

[Explanation of symbols]

Reference Signs List 1 mini disk, 2 cartridge main body, 3 magneto-optical disk, 7 recording / reproducing opening, 20 recording / reproducing device, 24 optical head, 41 objective lens, 42 biaxial actuator, 60 bobbin, 64 first annular convex portion, 65 second annular projection, 80 spindle

Claims (6)

[Claims] 1. A disc-shaped recording medium disposed in a recording and / or reproducing apparatus for irradiating light to a disk-shaped recording medium contained in a cartridge of a disc cartridge loaded in the recording and / or reproducing apparatus. An optical head for receiving light reflected by the disc-shaped recording medium; an objective lens for converging light emitted toward the disc-shaped recording medium and irradiating the light onto a signal recording surface of the disc-shaped recording medium A support shaft erected in a direction substantially parallel to an optical axis of light irradiated onto the signal recording surface of the disk-shaped recording medium; and A bobbin that moves in a direction substantially parallel to the optical axis of the light irradiated onto the signal recording surface of the recording medium and that rotates in a direction around the axis of the support shaft; and the support shaft and a part of the bobbin. Is on While facing the disc-shaped recording medium accommodated in the cartridge through an opening provided in one main surface of the cartridge, the other portion of the bobbin faces the one main surface of the cartridge, and An optical head, which irradiates light to a disc-shaped recording medium and receives light reflected by the disc-shaped recording medium. 2. The disk-shaped recording medium is irradiated with light and reflected by the disk-shaped recording medium in a state where the tip of the support shaft is inserted into the disk cartridge from the opening. 2. The optical head according to claim 1, wherein the optical head receives the light. 3. A wiring board for transmitting a driving force to the bobbin, and a part of the bobbin opposed to an opening provided on one main surface of the disk cartridge is connected to the wiring board. The optical head according to claim 1, further comprising a connection terminal portion. 4. A disk cartridge loading section for loading a disk cartridge containing a disk-shaped recording medium in a cartridge having an opening on one main surface; An optical head that irradiates the medium with light and receives light reflected by the disc-shaped recording medium, wherein the optical head focuses light emitted toward the disc-shaped recording medium. An objective lens that irradiates the signal recording surface of the disc-shaped recording medium with a support shaft that is erected in a direction substantially parallel to the optical axis of light that is irradiated on the signal recording surface of the disc-shaped recording medium; Supports the objective lens, and moves in a direction substantially parallel to the optical axis of light irradiated on the signal recording surface of the disc-shaped recording medium along the support axis. A disc provided with a bobbin rotating around the axis of the support shaft, wherein the support shaft and a part of the bobbin are accommodated in the cartridge via an opening provided on one main surface of the cartridge While irradiating the disc-shaped recording medium with the other portion of the bobbin facing one main surface of the cartridge, the disc-shaped recording medium is irradiated with light, and reflected by the disc-shaped recording medium. A recording and / or reproducing apparatus for receiving the light. 5. The optical head irradiates the disk-shaped recording medium with light while the tip end of the support shaft is inserted into the disk cartridge from the opening, and the optical head has a disk shape. 5. The recording and / or reproducing apparatus according to claim 4, wherein the light reflected by the recording medium is received. 6. The optical head includes a wiring board for transmitting a driving force to the bobbin, and a part of the bobbin opposed to an opening provided on one main surface of the disk cartridge includes the wiring board. The recording and / or reproducing apparatus according to claim 4, further comprising a connection terminal portion connected to the wiring board.