JPH07334884A - Fixed magneto-optical disk drive - Google Patents

Abstract

PURPOSE:To obtain a fixed magneto-optical disk drive, an optical system of which is easily adjustable at the time of manufacturing, and after manufacturing the drive. CONSTITUTION:An adjusting area is provided beforehand on the magneto-optical disk 1 to be mounted, and a signal suitable for adjusting and checking is arranged in the adjusting area, then the position of a photodetector 37 is adjusted in accordance with a reflected light of the laser beam with which the adjusting area is irradiated. By providing the adjusting area 20 on the magneto-optical disk 1 to be mounted on the drive, the signal obtained therefrom is utilized for adjusting the positional deviation of the photodetector 37 or for confirming the deterioration of the beam quality without disassembling the drive, not only at the time of manufacturing the drive but also at the time of after-sale service.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixed type magneto-optical disk drive suitable for application to a large-capacity external storage device using a fixed type magneto-optical disk.

[0002]

2. Description of the Related Art Conventionally, optical disc drives are of the type in which discs can only be exchanged, and since discs can be exchanged, optical adjustments and checks at the time of manufacture, or drive checks at the time of service, etc. By preparing a dedicated adjusting disk and using this adjusting disk, optimum adjustment can always be performed, and checking can always be performed under the same conditions. On the other hand, fixed type magnetic hard disk drive (HD
In D), it is not necessary to adjust the position by using the reproduction signal from the disk as in the case of adjusting the optical portion of the optical disk drive, and it is not necessary to provide means for that.

[0003]

By the way, when an optical disk is used to provide a fixed type magneto-optical disk drive such as a magnetic hard disk drive, the conventional optical disk drive is used to adjust the optical part. An adjustment mechanism equivalent to is required. Further, since the disc is of a fixed type, it is not easy to exchange the disc as compared with the conventional optical disc drive, and it is difficult to use the adjustment disc. Even if an adjustment disc is used, there is a problem in that when the adjustment disc is replaced with an original disc, the characteristics are deteriorated and variations occur, and the advantages of the fixed disc cannot be fully utilized. there were.

Therefore, an object of the present invention is to provide a fixed magneto-optical disk drive which can easily adjust an optical system after manufacturing the drive.

[0005]

In order to achieve the above object, the fixed magneto-optical disk drive according to the invention as defined in claim 1 is adjusted, checked, and maintained at least at one of the inner circumference, the middle circumference, and the outer circumference. A magneto-optical disk that is rotatably fixed in the housing and an adjustment area that is provided in the magneto-optical disk. An optical system that irradiates a laser beam, adjusts the position based on the reflected light, and records, reads, and erases the data by irradiating the magneto-optical disk with the laser beam. Characterize.

As a preferred aspect, for example, as described in claim 2, the adjustment area includes a mirror portion which is composed of a plurality of tracks and totally reflects laser light, a groove portion which is composed of a plurality of tracks, or a pit signal which is composed of a plurality of tracks. You may make it comprised by at least 1 type or more of a part. Further, for example, as described in claim 3, the position adjustment of the optical system may be performed at the time of manufacturing the drive or at the time of maintenance after manufacturing the drive.

[0007]

According to the present invention, the built-in magneto-optical disk is provided with an adjustment area in advance, a signal suitable for adjustment and check is arranged in the adjustment area, and the adjustment area is irradiated with laser light. Then, the position of the optical system is adjusted based on the reflected light. Therefore, the optical system can be easily adjusted at the time of manufacturing the drive and after the manufacturing, so that it becomes possible to improve workability, accuracy and reliability.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. A. Configuration of Embodiment FIG. 1 is a perspective view showing the configuration of a fixed type magneto-optical disk drive according to an embodiment of the present invention. In the figure, 1 is
This is a magneto-optical disk capable of recording and erasing data by a magnetic field modulation method, and has a hole 1a at the center thereof.
A shaft of a spindle motor 2 for rotating the magneto-optical disk 1 at a constant rotation speed is fitted in the hole 1a. Next, 3 is an objective lens for condensing light on the magneto-optical disk 1, and 4 is a drive unit for moving the objective lens 3 in the radial direction of the magneto-optical disk 1. A movable optical head 5 is configured by the objective lens 3 and the driving unit 4.

Reference numeral 6 denotes a galvanometer mirror, which bends the optical axis by 90 degrees and gives a small angle to the optical axis to move a minute point on the magneto-optical disk 1 by the objective lens 3 in the disk radial direction. Then, the converging point is made to follow the track on the magneto-optical disk 1. A magnetic head 7 is integrated with the optical head 5 and has an objective lens 3
Is arranged so that the center of the magneto-optical disk 1 and the center of the magnetic field are opposed to each other with the magneto-optical disk 1 interposed therebetween.

Reference numeral 8 denotes an optical fixing portion, which is a semiconductor laser which emits a laser beam for reading information from the magneto-optical disc 1, and which electrically reflects data on the disc and a servo signal from reflected light from the magneto-optical disc 1. It is composed of a photodetector that converts a static signal and other optical components such as a prism. The detailed configuration of the optical fixing portion 8 will be described later. Further, 9 is a chassis for fixing the components of the movable optical head 5 from the magneto-optical disk 1 described above. Reference numeral 10 denotes a top cover together with the chassis 9 for making the drive a closed structure.

Next, FIG. 2 is a schematic diagram for explaining the adjustment area provided on the magneto-optical disk 1. The above-described magneto-optical disk 1 has an inner circumference (ID) and a middle circumference (M
An adjustment area is provided in at least one of D) or the outer circumference (OD). In this embodiment, as shown in FIG. 2, an adjustment area 20 is provided on the inner circumference of the magneto-optical disk 1. The adjustment area 20 includes a mirror portion 2 for a plurality of tracks that reflects light as it is on a completely flat surface.
1. Groove 22, C consisting of continuous grooves for a plurality of tracks
A pit signal portion 23 of a plurality of track portions including pits such as D (compact disc) is provided.

Next, the structure of the optical system of this embodiment will be described with reference to FIG. FIG. 3 is a perspective view showing the configuration of the optical system of the fixed type magneto-optical disk drive of this embodiment.
In the figure, the above-mentioned optical fixing portion 8 includes a laser diode 30 that emits laser light of a predetermined wavelength, a collimator lens 31 that makes the laser light parallel light, a beam splitter 32 that splits the laser light in a predetermined direction, and a light beam. A doublet lens 33 and a multi-lens 34 for focusing the return light from the magnetic disk 1 on the photodetector 37 are appropriately arranged. Reference numeral 36 is a 45-degree mirror that changes the traveling direction of incident light to the vertical direction. A photo detector 37 is arranged behind the multi-lens 34.

In the structure described above, the laser light emitted from the laser diode 30 is collimated by the collimator lens 31.
After passing through the beam splitter 32, the direction of travel is changed counterclockwise by 90 ° at the end face of the beam splitter 32, and the direction of travel is changed clockwise by 90 ° at the other end of the beam splitter 32 for emission. Further, the laser light is reflected by the galvano mirror 6,
To the movable optical head 5 shown in FIG. This laser light is reflected by the 45-degree mirror 36 provided in the movable optical head 5, travels to the magneto-optical disk 1, and is condensed by the objective lens 3.

Thereafter, the laser light is reflected by the magneto-optical disk 1 and returns to the above-mentioned path. At this time, in the optical fixing unit 8, the return laser light that has reached the beam splitter 32 advances straight as it is, and the doublet lens 33
Then, the light enters the photodetector 37 through the multilens 34. The position of the photodetector 37 is adjusted by using the return laser beam incident on the photodetector 37. In the present embodiment, the astigmatism method is used as the focus signal detection method, and the photodetector 37 is in the shape of a letter, and is A, B, C, and D in the counterclockwise direction.
It is assumed to be divided. This photo detector 3
The position adjustment of 7 is performed during the assembly of the drive.

B. Operation of Embodiment Next, the adjusting operation in the above-described embodiment will be described. First, in the initial state (assembly during manufacturing), the position of the photodetector 37 is displaced,
Focus servo and tracking servo cannot be applied. At this time, as shown in FIGS. 4A to 4C, when the objective lens 3 is slowly vibrated up and down, the beam on the surface of the magneto-optical disk 1 is defocused, focused, and defocused. Repeat the state. In response to this,
If the photodetector 37 is arranged at a regular position, the shape of the beam on the photodetector 37 changes as shown in FIGS. 5A to 5C by the astigmatism method.

From this, based on the output signals of the areas A, B, C and D of the photodetector 37, (A + D)-
By performing the calculation of (B + C), S as shown in FIG.
It is known that an output signal Sfe called letter is obtained. Therefore, the position of the photodetector 37 is adjusted so that the output signal Sfe as shown in the figure is obtained. In FIG. 6, points P0 and P6 are cases where the objective lens 3 is close to the magneto-optical disk 1 as shown in FIG. 5A, and points P1 and P5 are as shown in FIG. 5B. When the focal points match, and the points P2 and P4 are shown in FIG.
This is the case where the objective lens 3 is close to the magneto-optical disk 1, as shown in FIG.

For the adjustment based on the S-shaped output signal Sfe, the quality of the signal is good and the workability is improved by using the mirror portion 21 which totally reflects the laser light shown in FIG. If a discontinuous surface such as a pit exists here, noise as shown in FIG. 7 is generated in the output signal Sfe, which deteriorates workability and accuracy. As described above, by adjusting the position of the photodetector 37, the focus servo can be applied for the first time in a state where the output signal shown in FIG. 6 is obtained.

After applying the focus servo, the position of the objective lens 3 is moved to the area formed by the groove 21 shown in FIG. Here, the outputs from the areas A, B, C, and D of the photo detector 37 are (A + B)-(C +
By performing D), a signal called push-pull (hereinafter referred to as push-pull signal) can be obtained.

At this time, since the tracking servo is not applied to the drive, the position of the objective lens 3 does not follow the track. Therefore, this groove 22
If there are a plurality of tracks, as shown in FIG. 8, the beam spot BS continuously moves between tracks in a state where the center of the beam spot BS and the center of the track TR do not coincide with each other due to deflection of the DC motor, eccentricity of the disk, or the like. To do. The arrow A shown in the figure
Indicates the moving direction of the track TR due to the rotation of the magneto-optical disk 1. As described above, when the track TR moves with respect to the beam spot BS, the photodetector 37 is irradiated with laser light having a light intensity distribution as shown in FIGS. 9A to 9C.

That is, in FIG. 8, when the left side of the beam spot BS is on the track TR,
As shown in (a), the light intensity on the right side becomes weak (hatched portion). Further, in FIG. 8, when the center of the beam spot BS is on the track TR, the light intensity on both sides becomes weak (hatched portion), as shown in FIG. 9B. Further, in FIG. 8, when the right side of the beam spot BS is on the track TR, the light intensity on the left side becomes weak (hatched portion), as shown in FIG. 9C. As a result, a continuous signal as shown in FIG. 10 is obtained from the photo detector 37.

At this time, if the center of the photodetector 37 divided into four parts and the center of the beam spot BS are completely coincident with each other, the signal shown in FIG. 10 has only an AC (alternating current) component, but even a small amount. If there is a deviation in the X direction, the DC (direct current) component is added. Therefore, the photodetector 37 is finely adjusted in the X direction so that this DC component is eliminated. Further, when the groove 22 crosses the beam spot BS due to eccentricity of the magneto-optical disk 1 or the like, a small amount of push-pull component also appears in the Y direction of the photodetector 37. Therefore, this time, (A + C)-(B + D) is calculated from the output signal of the photodetector 37, and by discriminating this signal, adjustment in the Y direction is performed similarly to the adjustment in the X direction described above. Also in these signals, if the groove 11 is cut off at several points along the way, it appears as noise, which causes deterioration of the adjustment accuracy.

Further, in the pit portion of the magneto-optical disk 1, as shown in FIG. 11A, a beam in which a skew (aberration) is generated due to tilting of the objective lens 3 is shown in FIG. When the pit is read, the light intensity of the beam spot of the objective lens 3 has a distribution as shown in FIG.
As a result, when the pits are read by a normal beam having no skew, the photodetector 37 divided into four gives an output sum signal as shown in FIG. When the pits are read with the beam that has been created, as shown in FIG.
An output sum signal deformed by skew is obtained. Therefore, the presence of the skew can be confirmed by discriminating the deformation of the output sum signal from the photo detector 37. If a mechanism that allows skew adjustment is added to the objective lens 3, the inclination of the objective lens 3 can be adjusted according to the output sum signal.

As described above, in this embodiment, the above-mentioned adjustment area 2 is added to the magneto-optical disk 1 mounted on the drive.
If 0 is provided, the signal obtained from this can be adjusted not only at the time of manufacturing the drive but also at the time of service, without adjusting the drive, to adjust the positional deviation of the photodetector 37 and to confirm the deterioration of the beam quality. .

[0024]

According to the present invention, the built-in magneto-optical disk is provided with an adjustment area in advance, and signals suitable for adjustment and checking are arranged in the adjustment area, and the adjustment area is provided in the adjustment area. Since the position of the optical system is adjusted based on the reflected light by irradiating the laser beam, it is not necessary to prepare an adjustment disc, and the adjustment and adjustment discs do not require manufacturing or maintenance. An advantage is that it is possible to eliminate the time and effort required for manufacturing the drive, such as replacing the disk with a disk that should be originally mounted in the drive later. Further, since the drive can be adjusted with the magneto-optical disk originally mounted in the drive, there is no need to replace the magneto-optical disk after the adjustment, and there is an advantage that the quality at the time of adjustment can be maintained. Further, even after the drive is manufactured, it can be inspected in the same manner as during the adjustment, the quality of the drive can be checked at any time, and the serviceability can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing the structure of a fixed type magneto-optical disk drive according to an embodiment of the present invention.

FIG. 2 is a schematic diagram for explaining an adjustment area provided on the magneto-optical disk in the example.

FIG. 3 is a perspective view showing a configuration of an optical system in the example.

FIG. 4 is a schematic diagram showing a defocusing state, a defocusing state, and a defocusing state of a beam on the surface of the magneto-optical disk when the objective lens is slowly vibrated up and down in the same example.

FIG. 5 is a schematic view showing the shape of a beam on the photodetector when the beam on the surface of the magneto-optical disk is repeatedly defocused, in-focus and defocused in the same example.

FIG. 6 is a waveform diagram showing an output signal called an S-shape obtained based on the output signals of the respective areas A, B, C, D of the photo detector in the embodiment.

FIG. 7 is a waveform diagram showing noise that appears in the output signal of the photodetector when there is a discontinuous surface such as a pit in the same example.

FIG. 8 is a schematic diagram showing movement of a beam spot when tracking servo is not applied in the embodiment.

FIG. 9 is a schematic diagram showing a light intensity distribution of laser light incident on a photodetector when tracking servo is not applied in the embodiment.

FIG. 10 is a waveform diagram showing an output signal of the photodetector when the tracking servo is not applied in the embodiment.

FIG. 11 is a schematic diagram for explaining the light intensity distribution of the beam spot of the objective lens when a skew (aberration) occurs due to the inclination of the objective lens in the example.

FIG. 12 is a waveform diagram showing an output signal of the photodetector when no skew occurs and an output signal of the photodetector when skew occurs in the embodiment.

[Explanation of symbols]

 1 Magneto-optical disk 2 Spindle motor 3 Objective lens 4 Drive part 5 Movable optical head 6 Galvano mirror 7 Magnetic head 8 Optical fixing part (optical system) 9 Chassis 10 Top cover 20 Adjustment area 21 Mirror part 22 Groove 23 Pit signal part 30 Laser diode 31 Collimator lens 32 Beam splitter 33 Doublet lens 34 Multi-lens 36 45 degree mirror 37 Photodetector (optical system)

Claims (3)

[Claims] 1. An adjustment area for adjusting, checking, and maintaining a drive is provided at least at one of the inner circumference, the middle circumference, and the outer circumference, and data is recorded.
A magneto-optical disk, which has an erasable area and is rotatably fixed in the housing, and an adjustment area provided on the magneto-optical disk are irradiated with laser light, and position adjustment is performed based on the reflected light. A fixed magneto-optical disk drive, further comprising: an optical system for recording, reading and erasing the data by irradiating the magneto-optical disk with laser light. 2. The adjustment area is composed of at least one kind of a mirror portion formed of a plurality of tracks and totally reflecting laser light, a groove portion formed of a plurality of tracks, or a pit signal portion formed of a plurality of tracks. The fixed magneto-optical disk drive according to claim 1, which is characterized in that. 3. The fixed magneto-optical disk drive according to claim 1, wherein the position adjustment of the optical system is performed at the time of manufacturing the drive or at the time of maintenance after manufacturing the drive.