JPH03144927A - Optical disk driving device - Google Patents

Abstract

PURPOSE:To facilitate the adjustment making a carriage moving axis and an optical axis coincident with each other by providing two objective lenses freely movable in the two directions on a plane in crossing with the optical axis of a light beam and adjusting the position of two directions of the objective lens. CONSTITUTION:Two objective lenses 12b, 12a are arranged in facing with an outgoing port 41 of a light beam. When the carriage moving shaft is deviated from an optical axis 6a, moving means 13a, 13b or 14a, 14b of the two objective lenses 12a, 12b by the same amount as the deviation to make the optical axis 6a coincident with the carriage moving shaft. Moreover, when the tilt is deviated, the deviation in the Y or Z direction at two points apart by a prescribed distance is detected in the X direction of an optical head 5 to adjust the moving means 13a or 14a in the Y or Z direction of the objective lens 12a. Thus, the optical axis 6a is made coincident with the carriage moving shaft with a simple operation.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an optical disk drive device that records, reproduces, and erases information using a light beam, and particularly relates to an optical disk drive device that uses a light beam to record, reproduce, and erase information. It relates to a drive device.

[Prior Art] FIG. 4 is a perspective view showing the structure of an optical disk drive device equipped with a conventional separation type optical head. In the figure, l denotes a base made of aluminum, and a disk motor 3 for rotating a disk-shaped disk 2 is fixed to one end of the base 1 with its rotating shaft protruding upward. A fixed optical head 4 is fastened to the other end of the base 1 for optically recording, reproducing, and erasing information. Disc motor 3
and the fixed optical head 4, two iron magnetic circuits 11 and 11 each having a side surface in which the open end of an E-shaped core is closed by a rectangular member are arranged so that the elongated direction is oriented in the radial direction of the disk 2 (hereinafter referred to as the X direction). ) and are fixed to the base 1 at an appropriate distance apart. Further, a rectangular pipe-shaped carriage 9 is provided on the central sides 11a and lla of the two magnetic circuits 11.11 so as to straddle and surround them so as to be movable in the X direction of the disk 2. A voice coil 10 is wound around the carriage 9, and the voice coil 10 and magnetic circuits 11.11 cooperate to move the carriage 9 in the X direction.

At the center of the carriage 9, there is a reflection mirror 7 that bends the light beam emitted from the fixed optical head 4 in the X direction in a direction perpendicular to the disk 2, and an objective that focuses the bent light beam onto the surface of the disk 2. A separation optical head 5 having a lens 8 is provided. The separation optical head 5 moves the objective lens 8 in the X direction and in the direction perpendicular to the disk 2 (hereinafter referred to as
It has a structure that allows slight movement in the direction (referred to as "direction"), and can position the light spot at a desired position on the surface of the disk 2 by following the surface wobbling and eccentricity of the disk 2.

Next, the operation of the conventional optical disc drive device configured as described above will be explained.

FIG. 5 is a schematic enlarged perspective view showing the adjustment procedure of a conventional optical disk drive device.

When the disk 2 is mounted on the rotating shaft of the disk motor 3, a predetermined current is passed through the voice coil 10, and the carriage is moved by the action of the current flowing through the voice coil 10 and the magnetic force lines generated in the magnetic circuit 11. A thrust force in the X direction is applied to the carriage 9, and the carriage 9 moves along the moving axis 6b in the X direction together with the separation optical head 5.

This operation allows the light beam emitted from the fixed optical head 4 to be roughly positioned in the X direction. The light beam passes through the reflection mirror 7 and the objective lens 8 and is irradiated onto the disk 2 surface as a light spot. At this time, the objective lens 8 is moved slightly in the X direction and the X direction to precisely position the light spot. conduct.

This makes it possible to access information such as recording, reproducing, and erasing information on the disc 2.

In a conventional optical disk drive device equipped with a separation type optical head, when the optical axis 6a of the light beam and the movement axis 6b of the carriage 9 are misaligned, the optical characteristics change and the separation optical head 5 becomes When moving in the axial direction, the light beam is not positioned in the X direction of the disk 2, leading to erroneous access to the disk 2, reducing the reliability of the device.

Therefore, in such an optical disk drive device, it is necessary to align the optical axis 6a with the moving axis 6b, and the fixed optical head 4
When fastening to base 1, its X direction, Z axis rotation, Y
The optical axis 6a and the movement axis 6b were made to coincide by adjusting the direction and four mounting directions around the Y axis.

[Problem to be solved by the invention]

However, such adjustment methods for conventional optical disk drives have many degrees of freedom in adjustment, making adjustment work difficult and requiring skill, requiring long time adjustment work, and increasing adjustment costs. There was a problem.

This invention was made in view of the above circumstances, and includes two objective lenses that are movable in two directions on a plane intersecting the optical axis of the light beam, and the positions of the two objective lenses in the two directions are adjusted. It is an object of the present invention to provide an optical disk drive device which facilitates the adjustment work of aligning the moving axis of a carriage with the optical axis and reduces the cost required for the adjustment work.

[Means for Solving the Problems] An optical disk drive device according to the present invention includes two objective lenses movable in two directions within a plane intersecting the optical axis of a light beam incident on a separation optical head. The movement in the two directions is performed by a moving means.

[Effect]

In this invention, after the fixed optical head is fixed to the base, the separation optical head is moved in the radial direction, and the deviation between the axis of movement thereof and the optical axis of the light beam is detected.

The two objective lenses are moved in the two directions by the moving means according to the detected deviation to eliminate the deviation.

〔Example〕

FIG. 1 is a perspective view showing the structure of an optical disc drive device according to the present invention. In the figure, reference numeral 1 denotes an aluminum base, and a disk motor 3 for rotating a disk-shaped disk 2 is fixed to one end of the base 1 with its rotating shaft protruding upward. A fixed optical head 4 is fastened to the other end of the base 1 for optically recording, reproducing, and erasing information. The fixed optical head 4 emits a light beam and detects the reflected beam from the disk 2.

Two objective lenses 12b facing the light beam exit aperture 41
, 12a are arranged in this order. objective lens l 2
a, 12b are Y-direction and X-direction moving means 13a, 13b, 14a, 1 using screws in two intersecting directions (Y direction and X direction) in a plane perpendicular to the optical axis 6a of the light beam;
4b, and the amount of movement is determined by the detection output of a photodetector 15, which will be described later.

Between the disk motor 3 and the fixed optical head 4, two iron magnetic circuits 11 and 11 each having a side surface with an open end of an E-shaped core closed by a rectangular member are arranged so that the longitudinal direction extends along the radial direction 1ti1 of the disk 2. (hereinafter referred to as the X direction), and are fixed to the base 1 at an appropriate distance apart. Also, the central side 11a of the two magnetic circuits 11.11.

A rectangular vibrator-shaped carriage 9 is provided on the disc 11a so as to be movable in the X direction of the disc 2 so as to straddle the disc 11a and surround it. A voice coil lO is wound around the carriage 9, and the voice coil 10 and the magnetic circuit 11.
11 to move the carriage 9 in the X direction.

At the center of the carriage 9, there is a reflection ξ mirror 7 that bends the light beam emitted from the fixed optical head 4 in the X direction in a direction perpendicular to the disk 2, and a reflection beam 7 that focuses the bent light beam onto the surface of the disk 2. A separation optical head 5 having an objective lens 8 is provided. The separation optical head 5 moves the objective lens 8 in the X direction and in the direction perpendicular to the disk 2 (hereinafter referred to as
It has a structure that allows slight movement in the direction (referred to as "direction"), and can position the light spot at a desired position on the surface of the disk 2 by following the surface wobbling and eccentricity of the disk 2.

The reflective ξ mirror 7 is formed by using a semi-transparent prism, and a four-part photodetector 15 serving as means for detecting the amount of deviation faces the back surface thereof. The photodetector 15 detects the deviation of the optical axis 6a from the center of the photodetector 15 in the Y direction and the X direction based on the amount of light on the four light receiving surfaces.

Note that the photodetector 15 is a two-dimensional position detection element (Eo
Any device that can two-dimensionally detect the amount of deviation such as a position sensing device may be used. The detection output of the photodetector 15 is processed by a signal processing circuit (not shown), and the amount of deviation is displayed two-dimensionally.

Next, a procedure for adjusting the optical axis 6a and the moving axis 6b of the optical disk drive device of the present invention constructed as above will be explained.

FIG. 2 is a schematic enlarged sectional view showing the optical axis adjustment procedure of the optical disk drive device of the present invention, and FIG. 3 is a diagram showing the types of deviations between the optical axis and the movement axis. There are two types of deviations between the optical axis 6a and the movement axis 6b: translational deviation and tilt deviation. As shown in FIG. 3(a), translational misalignment means that the optical axis 6a and the movement axis 6b are misaligned in parallel in the Y direction or the X direction, and in this case, the separation optical head 5 moves in the X direction. However, the detection output of the photodetector 15 in the Y direction or the X direction does not change. The tilt shift is a shift in which the optical axis 6a and the movement axis 6b cross each other in the Y direction or the X direction.In this case, when the separation optical head 5 moves in the X direction, the light in the Y direction or the The detection output of the detector 15 changes.

In the case of translational deviation, the two objective lenses 12a, 12b are moved by moving means 13a, 13b or 14a, 14 in the Y direction or
The optical axis 6a is aligned with the moving axis 6b by adjusting b by 11M, which is the same as the amount of deviation.

In the case of tilt deviation, the amount of deviation in the Y direction or the Adjust the moving means 13a or L4a in the Y direction or the X direction. Note that the objective lens 12b is not adjusted at this time.

These four transportation means 13a, 13b, 14a,
By adjusting 14b, after the fixed optical head 4 is attached to the base 1, the optical axis 6a can be aligned with the moving axis 6b by a simple adjustment operation. In addition, a photodetector 15 is provided on the back surface of the reflecting mirror 7, so that the translational displacement and inclination displacement of the optical axis 6a can be easily detected, thereby further facilitating the adjustment work of the moving means.

Next, the access operation of the optical disk drive of the present invention adjusted in this way will be explained.

When the disk 2 is mounted on the rotating shaft of the disk motor 3, a predetermined current is passed through the voice coil 10, and the carriage 9 A thrust force in the X direction is applied to the carriage 9, and the carriage 9 moves in the X direction together with the separation optical head 5. At this time, the moving axis 6b of the carriage 9 on which the separating optical head 5 is installed is aligned with the optical axis 6a of the light beam from the fixed optical head 4, and the optical axis 6a of the light beam is irradiated onto a predetermined position of the reflecting mirror 7. Ru. This operation allows the light beam emitted from the fixed optical head 4 to be roughly positioned in the X direction. The light beam passes through a reflecting mirror 7,
It passes through the objective lens 8 and is irradiated onto the disk 2 surface as a light spot. At that time, the objective lens 8 is slightly moved in the X direction and the X direction to closely position the light spot. It becomes possible to record, reproduce, and erase information.

In this embodiment, a screw is used as the moving means, and the optical axis is adjusted by adjusting the screw after the fixed optical head is attached to the base. However, the present invention is not limited to this, and the moving means may be, for example, The optical axis may be adjusted by using a near actuator to move the objective lens at a predetermined period according to the detection output from the photodetector. As a result, even if the optical characteristics change over time, the optical axis can be adjusted accordingly, further improving the reliability of the device.

Further, in this embodiment, the objective lens is provided facing the exit aperture of the fixed optical head, but it goes without saying that it may be made to move together with the separation optical head, or may be provided within the fixed optical head.

〔Effect of the invention〕

As explained above, in this invention, two objective lenses that are movable in two directions within a plane intersecting the optomagnetic direction of the light beam are provided between the fixed optical head and the separation optical head, and the optical axis of the light beam and By moving the two objective lenses in the two directions according to the amount of deviation from the radial movement axis of the separation optical head, the adjustment work to align the optical axis with the movement axis is facilitated, and the adjustment time is shortened. , it has excellent effects such as being able to reduce the cost required for it.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the structure of an optical disk drive according to the present invention, FIG. 2 is a schematic enlarged perspective view showing the optical axis adjustment procedure of the optical disk drive according to the present invention, and FIG. 3 is an optical axis and a moving axis. 4 is a perspective view showing the structure of a conventional optical disk drive equipped with a separate optical head, and FIG. 5 is a schematic enlarged perspective view showing the adjustment procedure of the conventional optical disk drive. It is a diagram. 2...Disc 4...Fixed optical head 5...
Separation optical head 6a...optical axis 6b...movement axis 1
2a, 12b...Objective lens 13a, 13b,
14a, 14b...Transportation means In the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] (1) An optical disk drive device that accesses the optical disk by focusing a light beam emitted from a fixed optical head whose relative position with respect to the optical disk is fixed onto one surface of the optical disk using a separation optical head that is movable in the radial direction of the optical disk. comprising two objective lenses movable in two directions within a plane intersecting the optical axis of the light beam incident on the separation optical head, and a moving means for moving the objective lenses in the two directions. Characteristic optical disc drive device.