JPH11144301A - Mounting adjustment method of reflective optical element in optical information recording / reproducing head - Google Patents

Abstract

(57) [Problem] To provide a reflection type optical element with high accuracy without requiring a complicated component configuration in an optical information recording / reproducing head. SOLUTION: One of both side surfaces orthogonal to the optical disk at the tip of an arm provided with a reflective optical element is opened, the other inner surface is used as a mounting seat surface, and a flat surface orthogonal to the reflective surface of the reflective optical element is provided. While the side surface is urged to the mounting seat surface through the opening on one side, the position of the reflective optical element is adjusted in a direction parallel to the optical axis of the incident light beam, and the position of the emitted light beam with respect to the objective optical system. Adjustment, rotation adjustment of the reflective optical element around an axis passing through the intersection of the reflective surface of the reflective optical element with the incident optical axis and orthogonal to the mounting seat surface, and adjusting the tilt angle of the emitted light beam with respect to the objective optical system. After this, the reflective optical element was bonded and fixed to the mounting seat surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for adjusting the mounting of a reflective optical element in an optical information recording / reproducing head.

[0002]

BACKGROUND OF THE INVENTION Recently, a magneto-optical disk drive having a surface recording density exceeding 10 Gbit / (inch) ² has been developed. In this apparatus, the angle of incidence of a laser beam on an objective optical system provided at the tip of a coarse movement arm that rotates, for example, in a direction intersecting the track of the magneto-optical disk is finely adjusted by a deflecting means such as a galvo mirror, and the fine movement is performed. It is considered that tracking is accurately performed at a narrow track pitch level of, for example, 0.34 μm. By the way, in such a coarse motion arm, after the light beam emitted from the laser light source is converted into a parallel light beam, the laser light beam is guided in a direction parallel to the magneto-optical disk via the deflecting means and is immediately incident on the objective optical system. The light is reflected and deflected by a reflective optical element such as a reflective prism in a direction perpendicular to the magneto-optical disk, and then condensed on the magneto-optical disk by an objective optical system. In addition, it was necessary to attach it without requiring a complicated component configuration.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above background, and the invention of claim 1 is to convert a light beam emitted from a laser light source into a parallel light beam and then deflect the light beam. The laser beam is reflected and deflected by a reflective optical element in a direction perpendicular to the optical disk immediately before being guided into a direction parallel to the optical disk through the means and incident on the objective optical system, and then focused on the optical disk by the objective optical system. In the information recording / reproducing head, one of both side surfaces orthogonal to the optical disk at the end of the arm on which the reflective optical element is provided is opened, and the other inner surface is used as a mounting seat surface. In a state in which a flat side surface perpendicular to the surface is urged to the mounting seat surface via the opening on the one side surface, the position of the reflective optical element is adjusted in a direction parallel to the optical axis of the incident light beam. The position of the emitted light beam is adjusted with respect to the objective optical system, and the reflection type optical element is centered on an axis passing through the intersection of the reflection surface of the reflection type optical element with the incident optical axis and orthogonal to the mounting seat surface. After adjusting the rotation and adjusting the tilt angle of the emitted light beam with respect to the objective optical system,
The reflection type optical element is bonded and fixed to the mounting seat surface.

[0004]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, near-field recording (NFR: near field recording) has been proposed in response to a demand for an external storage device accompanying the recent advancement of hardware and software related to a computer, especially a demand for a large storage capacity. field recordin
g) An outline of a magneto-optical disk recording / reproducing apparatus using a recording / reproducing method called a technique will be described with reference to FIGS.

FIG. 1 is an overall schematic diagram of the optical disk device. An optical disk 2 is mounted on a rotating shaft of a spindle motor (not shown) in the disk drive device 1. On the other hand, a rotating (coarse movement) arm 3 for reproducing or recording information on the optical disk 2 is mounted so as to be parallel to the recording surface of the optical disk 2. This rotating arm 3
Is rotatable about a rotation shaft 5 by a voice coil motor 4. A floating optical head 6 having an optical element mounted thereon is mounted on a tip of the rotating arm 3 facing the optical disk 2. In addition, the rotating arm 3
A light source module 7 having a light source unit and a light receiving unit is disposed in the vicinity of the rotation shaft 5 and is configured to be driven integrally with the rotating arm 3.

FIGS. 2 and 3 illustrate the distal end portion of the rotating arm 3, and particularly illustrate the floating optical head 6 in detail. The floating optical unit 6 is attached to the flexure beam 8 and is arranged to face the optical disc 2. The flexure beam 8 is fixed to the rotating arm 3 at the other end, and presses the floating optical unit 6 at the distal end portion in a direction in which the floating optical unit 6 comes into contact with the optical disc 2 by the elastic force of the flexure beam 8.

The floating optical unit 6 includes a floating slider 9, an objective lens 10, and a solid immersion lens (S
IL) 11 and a magnetic coil 12, and functions to converge a parallel laser beam 13 emitted from the light source module 7 onto the optical disc 2. A rising mirror 31 is fixed to the tip of the rotating arm 3 to guide the laser beam 13 to the floating optical unit 6. Objective lens 1 by rising mirror 31
The laser light flux 13 incident on 0 is converged by the refraction of the objective lens 10. A solid immersion lens (SIL) 11 is disposed near the light-collecting point.
The convergent light is applied to the optical disc 2 as finer evanescent light 15.

A magnetic coil 12 for recording in a magneto-optical recording system is formed around a solid immersion lens (SIL) 11 facing the optical disk 2. It can be applied on the surface. This evanescent light 1
5 and the magnetic coil 12 enable high-density recording and reproduction on the optical disk 2. The floating optical unit 6 floats by a very small amount due to the airflow generated by the rotation of the optical disk 2 and follows the surface runout of the optical disk 2. For this reason, focus control (focus servo) of the objective lens, which is required in the conventional optical disk device, is not required.

The light source module 7 mounted on the rotating arm 3 and the light beam guided to the floating optical unit 6 will be described in detail below with reference to FIGS. The rotating arm 3 has a floating type optical unit 6 mounted at the tip and a driving coil 1 for driving a voice coil motor 4 at the other end.
6 is fixed. The drive coil 16 is a flat coil, and is inserted and arranged in a magnetic circuit (not shown) with a gap. The rotating shaft 5 and the rotating arm 3 are provided with a bearing 17,
When the current is applied to the drive coil, the rotation arm 3 can be rotated about the rotation shaft 5 by the electromagnetic action with the magnetic circuit.

The light source module 7 mounted on the rotating arm 3 has a semiconductor laser 18, a laser drive circuit 19,
Collimating lens 20, composite prism assay 21, laser power monitor sensor 22, reflection prism 2
3, a data detection sensor 24 and a tracking detection sensor 25 are arranged. The laser beam in a divergent beam state emitted from the semiconductor laser 18 is converted into a parallel beam by the collimating lens 20. The cross-sectional shape of the parallel light beam is an elliptical shape due to the characteristics of the semiconductor laser 18, and it is inconvenient to narrow the light beam onto the optical disk 2 minutely. Therefore, the cross-sectional shape of the parallel light beam is shaped by making the parallel light beam having an elliptical cross section emitted from the collimating lens 20 enter the composite prism assay 21.

The entrance surface 21a of the composite prism assay 21
Has a predetermined slope with respect to the incident optical axis. By refracting the incident light, the cross-sectional shape of the parallel light beam can be shaped from an oval shape to a substantially circular shape. The shaped laser beam travels through the complex prism assay 21 and enters the first half mirror surface 21b. The first half mirror surface 21b transmits information obtained from the optical disk 2 to the data detection sensor 24 and the tracking detection sensor 25.
However, on the outward path, it serves to separate the light beam to the laser power monitor sensor 22 for detecting the output power of the laser emitted from the semiconductor laser 18.

Since the laser power monitor sensor 22 outputs a current proportional to the intensity of the received light, the output of the semiconductor laser 18 can be stabilized by feeding back this output to a laser power control circuit (not shown). . The laser beam 13 having a substantially circular cross-sectional shape and emitted from the composite prism assay 21 is applied to the deflecting mirror 26, and the traveling direction of the laser beam 13 is changed. The deflecting mirror 26 is attached to a galvano motor 27 having a rotation center about an axis perpendicular to the plane of the paper, and can deflect the laser beam 13 by a small angle in a direction parallel to the plane of the paper.

The galvano motor 27 is provided with a deflection mirror position detection sensor 28 for detecting the rotation angle of the deflection mirror 26. The laser beam 13 reflected by the deflecting mirror 26 is transmitted to the first relay lens 29 and the second relay lens 29.
After passing through a relay lens (imaging lens) 30, the light is reflected by a rising mirror 31 and reaches the floating optical unit 6. The first relay lens 29 and the second relay lens 30 make the relationship between the reflection surface of the deflecting mirror 26 and the pupil surface (principal plane) of the objective lens 10 arranged in the floating optical unit 6 into a conjugate relationship. That is, a relay lens optical system is formed. That is, when the condensed beam on the optical disk 2 is slightly deviated from a predetermined track, the deflecting mirror 26 is slightly rotated to tilt the laser beam 13 incident on the objective lens 10 to move the focal point on the optical disk 2. Correction. However, when performing focus correction with this method,
If the optical distance between the deflecting mirror 26 and the objective lens 10 is long, the amount of movement of the laser beam 13 incident on the objective lens 10 increases, and it may not be possible to enter the objective lens 10.

In order to avoid such a phenomenon, the first relay lens 29 and the second relay lens 30
The relationship between the reflection surface of the deflecting mirror 26 and the pupil surface of the objective lens 10 is set to be a conjugate relationship, and even if the deflecting mirror 26 rotates, the laser beam 13 incident on the objective lens 10 does not move, Tracking control is made possible. The access operation over the inner circumference / outer circumference of the optical disk 2 is performed by rotating the rotating arm 3 by the voice coil motor 4, and only minute tracking control is performed by rotating the deflection mirror 26.

The return laser beam 13 reflected from the optical disk 2 and returning returns to the deflecting mirror 2 in a direction opposite to the forward path.
The reflected light is incident on the composite prism assay 21.
Thereafter, the light is reflected by the first half mirror surface 21b and travels to the second half mirror surface 21c. The second half mirror surface 21c generates transmitted light directed to the tracking detection sensor 25 and reflected light directed to the data detection sensor 24, and separates the laser beam on the return path. The laser beam transmitted through the second half mirror surface 21c is applied to the tracking detection sensor 25, and outputs a tracking error signal.

On the other hand, the laser beam reflected by the second half mirror surface 21c is polarized and separated by the Wollaston prism 32, converted into convergent light by the condensing lens 33, and then reflected by the reflecting prism 23 to be detected by the data detection sensor. 24. The data detection sensor 24 has two light receiving areas, and receives two polarized beams polarized and separated by the Wollaston prism 32 to read data information recorded on the optical disk 2 and output a data signal. To be precise, the tracking error signal and the data signal are generated by a head amplifier circuit (not shown) and sent to a control circuit or an information processing circuit.

Next, the mounting structure of the rising mirror 3 in the above-mentioned rotating arm 3 will be described. FIG. 6 is a perspective view showing the tip of the rotating arm 3. The distal end of the rotating arm 3 (hereinafter referred to as the arm distal end 300) is configured as a U-shaped channel whose lower part is open. A pair of plate members on both sides of the U-shape are referred to as side plates 302 and 303, and a plate member between the side plates 302 and 303 is referred to as a top plate 301. A rising mirror 31 for reflecting the laser beam 13 toward the floating optical unit 6 (FIG. 5) is provided at the arm tip 300. The rising mirror 31 is a triangular prism having a right-angled isosceles triangular cross section.

The top plate 301 and the right side plate 303 in the figure are cut out (notch 320) at the protruding end of the arm tip 300, and the left side plate 302 in the figure is raised and the fixing mirror 31 is bonded and fixed. It is a seat for you.
By fixing one side surface 312 of the rising mirror 31 to the side plate 302, the rising mirror 31 is moved to the arm tip 3
Attach to 00.

FIG. 7 is a perspective view showing an adjusting device used for adjusting the mounting position and the mounting angle of the rising mirror 31. As shown in FIG. The adjusting device 150 has an engaging portion at its distal end for engaging with the rising mirror 31.
1 and can be moved in the R and T directions in the figure. The notch 320 in the arm tip 300 allows the adjustment device 150 to easily access the rising mirror mounting position of the arm tip 300. The adjusting device 150 includes an unillustrated bonding unit.

FIGS. 8 and 9 show a method of adjusting the mounting position and the mounting angle of the rising mirror 31, respectively. As shown in FIG. 8, by moving the rising mirror 31 horizontally along the optical axis 13, it is possible to adjust the position of the optical axis incident on the floating optical unit 6. Further, as shown in FIG. 9, by adjusting the rotation of the rising mirror 31,
The tilt angle of the optical axis incident on the floating optical unit 6 can be adjusted. By such adjustment, a spot having excellent optical performance can be formed on the optical disc 2 from the floating optical unit 6.

[0021]

As described above, according to the mounting method of the reflection type optical element in the optical information recording / reproducing head of the present invention, the reflection type optical element is mounted with high accuracy without requiring a complicated component structure. It becomes possible.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a basic configuration of a magneto-optical disk device according to an embodiment.

FIG. 2 is a diagram showing a distal end portion of a rotating arm.

FIG. 3 is a cross-sectional view showing a floating optical unit.

FIG. 4 is a plan view showing a deflection mirror and a floating optical unit.

FIG. 5 is a side sectional view of a rotating arm.

FIG. 6 is a diagram showing a distal end portion of a rotating arm.

FIG. 7 is a diagram showing a mounting and adjusting device for a deflecting mirror.

FIG. 8 is a diagram illustrating a method of adjusting a mounting position of a deflecting mirror.

FIG. 9 is a diagram illustrating a method of adjusting a mounting angle of a deflecting mirror.

[Explanation of symbols]

 Reference Signs List 3 rotating arm 31 rising mirror 150 adjusting device 300 arm tip 301 top plate 302, 303 side plate 320 notch

Claims (1)

[Claims] A light beam emitted from a laser light source is converted into a parallel light beam, and then guided in a direction parallel to the optical disk via a deflecting means to reflect the laser light beam in a direction perpendicular to the optical disk immediately before being incident on an objective optical system. In an optical information recording / reproducing head for reflecting and deflecting light by an optical element and condensing it on an optical disk by the objective optical system, one of two side surfaces orthogonal to the optical disk at the tip of an arm provided with the reflective optical element is opened. The other inner surface is used as a mounting seat surface, and the flat side surface orthogonal to the reflecting surface of the reflective optical element is urged to the mounting seat surface via the opening of the one side surface, and the reflection is performed. The position of the type optical element is adjusted in a direction parallel to the optical axis of the incident light beam to adjust the position of the output light beam with respect to the objective optical system. After adjusting the angle of rotation of the reflective optical element about an axis passing through the intersection with the optical axis and orthogonal to the mounting seat surface and adjusting the tilt angle of the emitted light beam with respect to the objective optical system, the reflective optical element A method for adjusting the mounting of a reflective optical element in an optical information recording / reproducing head, the method comprising: adhering and fixing to a mounting seat surface.