JPH11185281A - Optical head device and its adjustment method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct deviation in a radiation angle of a light beam radiated from a light source without increasing the number of parts. SOLUTION: An adjustment mechanism adjusting the radiation angle in the minor axis on the beam section of the light beam radiated from the light source of an optical head device is provided with a support member 102 supporting the light source 30 and a fixed member 104 fixed to a housing side. The support member 102 is provided with a projecting cylindrical surface 102a, and an axial direction prescribing the cylindrical surface 102a is parallel to the major axis on the beam section. The fixed member 104 is provided with a recessed shape cylindrical surface 104a having the same radius of aperture as the cylindrical surface 102a of the support member 102. The support member 102 is slid along the cylindrical surface 104a of the fixed member 104.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical head device applied to an optical disk device for reading information from an optical disk as a recording medium and recording information on the optical disk, and in particular, radiates from a light source of the optical head device. The present invention relates to an adjustment mechanism and an adjustment method for adjusting a radiation angle of a light beam.

[0002]

2. Description of the Related Art An optical disk device includes an optical head device having an objective lens and a photodetector, and irradiates a recording medium, that is, a recording surface of the optical disk, with a light beam from a semiconductor laser element to generate information recorded on the optical disk. It is used to record information on an optical disk while reading out information by extracting the corresponding reflected light.

In the above-described optical head device, a semiconductor laser element as a light source for generating a light beam, and a light beam emitted from the semiconductor laser element are focused on a recording surface of an optical disk as a recording medium and are reflected by the recording surface. An objective lens for extracting the reflected light beam, and a plurality of photodetectors or photodetectors for detecting and photoelectrically converting the reflected light beam extracted by the objective lens and outputting a reproduction signal corresponding to information recorded on the optical disc; , Are formed by a plurality of optical members and the like which constitute an optical path of a light beam between the respective elements.

[0004]

A semiconductor laser device used as a light source emits a light beam having an elliptical beam cross section. That is, the light beam from the semiconductor laser element is emitted at a beam cross section at a radiation angle of, for example, 25 ° in the major axis direction and at a radiation angle of, for example, 10 ° in the minor axis direction.

Also, a semiconductor laser device cannot always emit a light beam in a direction perpendicular to the reference surface of the device. That is, the light beam from the semiconductor laser device is emitted with a tolerance of, for example, ± 2 ° in the major axis direction and the minor axis direction in the beam cross section.

For this reason, the center of luminance of the light beam emitted from the semiconductor laser device may be shifted from the optical axis. The deviation of the radiation angle with respect to the optical axis, that is, the slight deviation of the luminance center, increases as the optical path from the light source to the recording surface of the optical disk becomes longer. This causes a problem that it is difficult to accurately read information from the optical disk, and it is difficult to accurately record information on the optical disk.

Therefore, it has been proposed to arrange a glass plate in the optical path from the light source to the recording surface of the optical disk so as to be inclined with respect to the optical axis to correct the deviation of the emission angle of the light beam. In this case, there is a problem that the number of components is increased and the cost is increased, and it is necessary to secure an area for disposing the glass plate, which is disadvantageous for downsizing the apparatus.

According to the present invention, it is possible to correct a deviation of a radiation angle of a light beam radiated from a light source without increasing the number of parts, to accurately reproduce information recorded on a recording medium, and to reproduce information from a recording medium. It is an object of the present invention to provide an optical head device capable of accurately recording information and a method of adjusting the optical head device.

[0009]

SUMMARY OF THE INVENTION The present invention has been made based on the above-mentioned problems. A first aspect of the present invention is a light source for emitting a light beam having an elliptical beam cross section, and a light source having a predetermined curvature. Adjusting means for moving along a cylindrical surface having a radius to adjust a radiation angle in a short-axis direction in a beam cross section of a light beam emitted from the light source; and a light source radiating the light beam emitted from the light source on a recording surface of a recording medium. Light collecting means for condensing light at a predetermined position, and receiving and photoelectrically converting a reflected light beam from the recording medium reflected by a recording surface of the recording medium,
An optical head device comprising: a photoelectric conversion unit that outputs an electric signal having a magnitude corresponding to light intensity.

A second aspect of the present invention provides a light source that emits a light beam having an elliptical beam cross section, a support member having a convex cylindrical surface having a predetermined radius of curvature, and supporting the light source; A fixing member having a concave cylindrical surface having the same radius of curvature as the convex cylindrical surface such that the convex cylindrical surface is slidable in the short axis direction in the beam cross section;
Condensing means for condensing a light beam emitted from the light source at a predetermined position on a recording surface of a recording medium, and receiving a reflected light beam from the recording medium reflected by the recording surface of the recording medium, and An optical head device comprising: a photoelectric conversion unit that converts and outputs an electric signal having a magnitude corresponding to the light intensity.

A third aspect of the present invention provides a light source that emits a light beam having an elliptical beam cross section, a convex cylindrical surface having a predetermined radius of curvature, and an axial direction defining the cylindrical surface and the beam cross section. A supporting member that supports the light source so that the minor axis direction is coincident with the convex cylindrical surface such that the convex cylindrical surface of the supporting member is slidable in the minor axis direction in the beam cross section. A fixing member having a concave cylindrical surface having the same radius of curvature; a light condensing means for condensing a light beam emitted from the light source at a predetermined position on a recording surface of a recording medium; And a photoelectric conversion unit that receives the reflected light beam from the recording medium, performs photoelectric conversion, and outputs an electric signal having a magnitude corresponding to the light intensity. Things.

According to a fourth aspect of the present invention, there is provided a light source for emitting a light beam having an elliptical beam cross section, a convex first cylindrical surface having a first radius of curvature and a second radius of curvature smaller than the first radius of curvature. A support member having a convex second cylindrical surface, and supporting the light source such that an axial direction defining the first and second cylindrical surfaces coincides with a short axis direction in the beam cross section; The first cylindrical surface of the first member is slidable in the minor axis direction in the beam cross section.
A fixing member having a concave cylindrical surface having the same first radius of curvature as the cylindrical surface, and forming a gap between the second cylindrical surface of the support member and the concave cylindrical surface; Condensing means for condensing the reflected light beam at a predetermined position on the recording surface of the recording medium, and receiving and photoelectrically converting the reflected light beam from the recording medium reflected by the recording surface of the recording medium to obtain light intensity. And a photoelectric conversion unit that outputs an electric signal having a size corresponding to the above.

A fifth aspect of the present invention provides a light source for emitting a light beam having an elliptical beam cross section, a first cylindrical surface having a first radius of curvature and a second radius of curvature smaller than the first radius of curvature. A support member having a convex second cylindrical surface, and supporting the light source such that an axial direction defining the first and second cylindrical surfaces coincides with a short axis direction in the beam cross section; The first cylindrical surface of the first member is slidable in the minor axis direction in the beam cross section.
A fixing member having a concave cylindrical surface having the same first curvature radius as the cylindrical surface, and forming a gap of 0.3 mm or less between the second cylindrical surface of the support member and the concave cylindrical surface; Condensing means for condensing a light beam emitted from the light source at a predetermined position on a recording surface of a recording medium, and receiving a reflected light beam from the recording medium reflected by the recording surface of the recording medium, and An optical head device comprising: a photoelectric conversion unit that converts and outputs an electric signal having a magnitude corresponding to the light intensity.

A sixth aspect of the present invention provides a light source that emits a light beam having an elliptical beam cross section, a convex cylindrical surface having a predetermined radius of curvature, and an axial direction defining the cylindrical surface and the beam cross section. A supporting member that supports the light source so that the minor axis direction is coincident with the convex cylindrical surface such that the convex cylindrical surface of the supporting member is slidable in the minor axis direction in the beam cross section. A fixing member having a concave cylindrical surface having the same radius of curvature, bonding means for bonding the support member to the fixing member in a state where the luminance center of the light beam emitted from the light source coincides with the optical axis, and the light source A light condensing means for condensing a light beam radiated from the recording medium at a predetermined position on a recording surface of the recording medium, and receiving a light beam reflected from the recording medium reflected by the recording surface of the recording medium and performing photoelectric conversion. , Compatible with light intensity There is provided an optical head apparatus characterized by comprising a photoelectric conversion means for outputting an electric signal of magnitude that, the.

A light source that emits a light beam having an elliptical beam cross section, a convex cylindrical surface having a predetermined radius of curvature, and an axial direction defining the cylindrical surface and the beam cross section are provided. A supporting member that supports the light source so that the minor axis direction is coincident with the convex cylindrical surface such that the convex cylindrical surface of the supporting member is slidable in the minor axis direction in the beam cross section. A fixing member having a concave cylindrical surface having the same radius of curvature, a screw for fixing the support member to the fixing member in a state where the luminance center of the light beam emitted from the light source coincides with the optical axis, and Light-collecting means for condensing the emitted light beam at a predetermined position on the recording surface of the recording medium, and receiving and photoelectrically converting the reflected light beam from the recording medium reflected by the recording surface of the recording medium;
An optical head device comprising: a photoelectric conversion unit that outputs an electric signal having a magnitude corresponding to light intensity.

According to another aspect of the present invention, a light source that emits a light beam having an elliptical beam cross section is moved along a cylindrical surface having a predetermined radius of curvature, and a short-axis direction in the beam cross section of the light beam emitted from the light source is provided. And a method for adjusting an optical head device, wherein the emission angle is adjusted.

According to a ninth aspect of the present invention, a light source that emits a light beam having an elliptical beam cross section is supported by a supporting member having a convex cylindrical surface having a predetermined radius of curvature, and the convex cylindrical surface of the supporting member is provided. Is slid on the concave cylindrical surface having the same radius of curvature as the convex cylindrical surface to adjust the radiation angle in the short-axis direction in the beam cross section of the light beam emitted from the light source, and emitted from the light source. And fixing the support member to the fixing member in a state where the luminance center of the light beam coincides with the optical axis.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the optical head device according to the present invention will be described below in detail with reference to the drawings. FIG.
As shown in FIG. 1, an optical disk device 100 includes an actuator 4 movable in a direction parallel to a recording surface (not shown) of an optical disk D as a recording medium and orthogonal to a track (not shown) provided on the recording surface. 4
And a laser beam transmission / reception unit 6 for transmitting a laser beam having a predetermined wavelength toward the laser beam and receiving the laser beam returned from the actuator 4.

The actuator 4 is moved in a direction orthogonal to a track (not shown) on a recording surface (not shown) of the optical disc D, that is, in a radial direction of the optical disc D based on a drive signal from the control unit 8.

The laser beam transmitting / receiving unit 6 includes a control unit 8
A laser beam for recording is emitted at the time of writing or recording information, and a laser beam for reproduction at the time of reading information or reproducing.

The control unit 8 supplies a predetermined control signal to the control unit 8 based on a read or write command (command) from an external device (not shown) input via the signal processing unit 10 and also controls the laser beam. The information signal received and transmitted by the transmission / reception unit 6 and photoelectrically converted is decoded and output to an external device as a reproduction signal.

The actuator 4 forms a laser beam for recording or reproduction from a light source, which will be described later, of the laser beam sending / receiving unit 6 at a predetermined position on a recording surface (not shown) of the optical disk D, and also forms an image on the optical disk D. An objective lens 12 as a condensing means for extracting the reflected laser beam Lr reflected on the recording surface, and the objective lens 12 is mounted on an optical disc D
In a direction orthogonal to the recording surface of the recording surface and in a direction traversing a track composed of a pit row which is information recorded on the recording surface (in a region where information is not recorded on an optical disc capable of recording information, a guide groove or groove). A pickup 14, which is movably held along a recording surface;
It has a carriage 18 that supports the pickup 14 so as to be movable in the radial direction of the optical disc D along a pair of guide rails 16.

The pickup 14 is, as shown in FIG.
Base 14a mounted at a predetermined position on carriage 18
Includes a cylindrical lens holder 14c formed to be rotatable around a center axis 14b extending in a direction orthogonal to the recording surface of the optical disc D from the lens holder 14c.
The objective lens 12 is held on a lens holding surface 14d provided at one end of the lens. Either the pickup 14 or the carriage 18 has a laser beam transmission /
A mirror 20 for guiding the laser beam Lf from the light receiving unit 6 toward the objective lens 12 is provided.

At a predetermined position on the outer peripheral surface of the lens holder 14c, focusing for generating a thrust for moving the objective lens 12 (lens holder 14c) in a direction perpendicular to the recording surface of the optical disk D, that is, along the central axis 14b. Coil 14e and objective lens 12 (lens holder 14c)
Coil 14f for generating a thrust for moving the optical disc D in a direction crossing the track on the recording surface of the optical disc D
Are provided along the curved surface of the outer peripheral surface.

The lens holder 1 around the center axis 14b
The area surrounding the outer peripheral surface of the lens holder 4c has a lens holder 14c.
Sets of fixed magnets 14g and 14h that provide a magnetic field in a predetermined direction toward each of the coils 14e and 14f on the outer peripheral surface of
And a yoke 14i which holds the fixed magnets 14g and 14h and cooperates with each magnet to form a magnetic circuit.
Is provided. In addition, the yoke 14i is
It is divided or arranged in an annular shape along or near a circumference set to have a substantially equal radius from b.

As shown in FIG. 3, the laser beam transmitting / receiving unit 6 is arranged at a predetermined position in the housing 6a and the housing 6a, and converts a linearly polarized light beam whose vibration direction is substantially aligned in one direction. Outgoing light source 30, housing 6
The light beam emitted from the light source 30 is disposed at a predetermined position in the optical disk D, and the reflected light beam reflected by the recording surface of the optical disk D is separated from the light beam traveling toward the optical disk D. The polarizing beam splitter 32 is disposed at a predetermined position in the housing 6a,
A collimating lens 34 disposed between the polarizing beam splitter 32 and the mirror 20 for collimating the light beam directed to the mirror 20 of the actuator 4; and a collimating lens 34 disposed at a predetermined position in the housing 6a and passing through the collimating lens 34. It has a retarder (λ / 4 plate) 36 for converting the direction of polarized light from linearly polarized light to circularly polarized light, and an elliptical correction prism 38 for correcting the aspect ratio of a light beam passing through the λ / 4 plate 36 into a substantially circular shape. .

The laser beam transmission / reception unit 6 converts the reflected laser beam Lr reflected by the recording surface of the optical disk D and returned via the actuator 4 from the laser beam Lf directed to the mirror 20 by the polarization beam splitter 32. Beam splitter (half mirror) for further splitting the separated reflected laser beam Lr into two laser beams
40, a first photodetector 42 and a second photodetector 42 serving as photoelectric conversion means for detecting and photoelectrically converting each of the two laser beams split by the half mirror 40 and converting them into electric signals corresponding to the respective laser beam light intensities.
The photodetector 46 of FIG.

A hologram plate (diffraction) for providing a predetermined optical characteristic to one of the laser beams split by the half mirror 40 between the second photodetector 46 and the half mirror 40 for detecting a focus shift. (Element) 48 is disposed.

The light source 30 is, for example, a semiconductor laser device that emits a laser beam Lf having a wavelength of 650 nm (nanometers). The direction of linearly polarized light of the emitted laser beam Lf is determined by a polarization plane (not shown) of a polarization beam splitter 32. It is fixed so that it is in the direction of reflection.
The laser beam emitted from the semiconductor laser element 30 has a substantially elliptical beam cross section. That is, the semiconductor laser element 30 emits a laser beam such that the beam cross section in one axial direction is longer than the other in the beam cross section.

The polarization beam splitter 32 has a polarization plane (beam split plane) (not shown) in which the direction of polarization is set so as to be orthogonal to the direction of linear polarization of the laser beam Lf emitted by the semiconductor laser element 30. The laser beam Lf from the laser element 30 is bent by 90 °, and the reflected laser beam Lr reflected by the optical disk D is passed.

The λ / 4 plate 36 is a polarizing beam splitter 3
2 changes the direction of polarization of the laser beam Lf reflected from the optical disk D from linearly polarized light to circularly polarized light, and changes the direction of polarization of the reflected laser beam Lr reflected from the optical disc D from circularly polarized light to
The light is converted into linearly polarized light again. At this time, the λ / 4 plate 36 causes a 90 ° phase difference between the polarization direction of the laser beam Lf traveling from the polarization beam splitter 32 toward the optical disk D and the polarization direction of the Lr returned from the optical disk D. Given. As a result, the Lr reflected by the optical disc D passes through the polarization plane of the polarization beam splitter 32 and is directed to the half mirror 40.

The surface of the elliptical correction prism 38 on the side of the polarization beam splitter 32 is used to transfer a part of the laser beam Lf from the semiconductor laser element 30 toward the optical disk D to the polarization beam splitter 32 in connection with APC (auto power control) described later. To return to the side, the semiconductor laser element 30
Of the laser beam Lf emitted from the lens and the objective lens 1
2 at a predetermined angle with respect to an optical axis O defined between the optical axis O and the axis connecting the reflection point (reflection center) of the laser beam Lf on the polarization beam splitter 32 and the reflection point (reflection center) on the mirror 20. Just tilted. The incident surface 38a of the elliptical correction prism 38 is formed on a mirror surface that reflects approximately 5 to 50% of the laser beam Lf incident from the semiconductor laser device 30 side.

The first photodetector 42 is used for detecting a track shift and has a light receiving area divided into four. Also, the first photodetector 42
For power control, independently of the four-divided photodetector, reflected by the incident surface 38a of the elliptic correction prism 38 and returned in a short optical path in a short time as compared with the reflected laser beam Lr from the recording surface of the optical disc D A monitor photodetector 44 that receives the laser beam (Lf) and performs photoelectric conversion is integrally incorporated.

The monitor photodetector 44 has a laser beam (L) used for auto power control (hereinafter, referred to as APC) for maintaining a constant light intensity of the laser beam Lf emitted from the semiconductor laser element 30.
The change in the light intensity of f) is monitored, and an output current corresponding to the change in the light intensity is output.

The second photodetector 46 is used for detecting a later-described defocus signal for matching the focusing between the objective lens 12 and the recording surface of the optical disc D. The second photodetector 46 has a light receiving area divided into four, receives a laser beam divided into a plurality of beams by a hologram plate 48 having a hologram diffraction pattern, and corresponds to each light receiving area. Outputs a large amount of current.

The control unit 8 includes a CPU 5 serving as a main control device.
0, a read-only memory (read only memory, hereinafter referred to as ROM) 5 which is connected to the CPU 50 and stores initial data for operating the CPU 50
2. A random access memory (hereinafter, referred to as a RAM) 54 for holding information to be recorded supplied from an external device (not shown) or data read from the optical disk D, and temporarily stores data input / output to / from the RAM 54. It has a buffer memory 56 for temporarily storing.

The CPU 50 includes a laser driving circuit 62 for supplying a predetermined driving current to the semiconductor laser element 30 to output a laser beam Lf having a predetermined light intensity, and a semiconductor corresponding to information to be recorded stored in the RAM 54. Laser element 3
A recording laser beam generating circuit 64 for changing the intensity of the laser beam Lf emitted from the zero is connected. When reading information from the optical disc D, the recording laser beam generating circuit 64 uses 1 / one of the recording laser beam.
A reproduction laser beam having a constant intensity of about 5 is emitted.

Further, the CPU 50 is connected to the monitor photodetector 44, and outputs the laser beam Lf emitted from the semiconductor laser element 30 based on the intensity of the laser beam (Lf) reflected on the incident surface 38a of the elliptic correction prism 38. A that defines the control amount for maintaining the strength constant
A PC (auto power control) circuit 66 is connected. It is needless to say that the output of the APC circuit 66 is fed back to the laser drive circuit 62.

The CPU 50 is also connected to the first photodetector 42 and receives a reflected laser beam Lr reflected by the optical disk D and receives a reflected laser beam Lr and photoelectrically converts the reflected laser beam Lr based on a track shift amount obtained from a current value obtained. A track control circuit 70 for setting a current value to be supplied to the tracking coil 14f of the holder 14c is connected.

The CPU 50 is further connected to a second photodetector 46, which receives the reflected laser beam Lr reflected by the optical disc D and performs an objective based on a focus shift amount obtained from a current value obtained by photoelectric conversion. A focus control circuit 74 for controlling the magnitude of a drive current to the focus coil 14e for controlling the position of the lens 12, that is, the lens holder 14c, is connected.

Incidentally, the semiconductor laser element 30 as a light source is mounted on a housing 6a of the laser beam transmitting / receiving section 6 via an adjusting mechanism 100 as adjusting means. This adjusting mechanism 100 is provided with
00 and the housing 6
and a fixing member 104 fixed to the a side and receiving the support member 102.

In the example shown in FIG. 3, the semiconductor laser element 30 forms a beam cross section on the XY plane and emits a laser beam in the Z-axis direction. Has an elliptical shape with the X-axis direction as the major axis and the Y-axis direction as the minor axis. That is, the radiation angle of the laser beam emitted from the semiconductor laser element 30 in the X-axis direction is, for example, 25 °.
And the radiation angle in the Y-axis direction is, for example, 10 °.

In such a semiconductor laser device 30, a light beam cannot always be emitted in the direction perpendicular to the reference surface of the device. That is, the laser beam from the semiconductor laser element is emitted with a tolerance of, for example, ± 2 ° in the major axis direction and the minor axis direction in the beam cross section. For this reason, the center of luminance of the laser beam emitted from the semiconductor laser device may be shifted from the optical axis parallel to the Z axis.

As described above, ± 2 in the X-axis direction and the Y-axis direction
When there is a tolerance of °, the radiation angle in the short-axis direction, that is, the Y-axis direction in the beam cross section is smaller than the long-axis direction, that is, the X-axis direction.

For this reason, the adjusting mechanism 100 applied to the semiconductor laser element 30 has a radiation angle in the short axis direction, that is, the Y axis direction in this embodiment, in the beam cross section of the laser beam emitted by the semiconductor laser element 30. To adjust. That is, the adjustment mechanism 100 is rotatably formed in the YZ plane, and is capable of correcting a shift in the Y axis direction with respect to the optical axis, that is, the Z axis.

FIG. 4 is a perspective view in which the support member 102 and the fixing member 104 constituting the adjusting mechanism 100 are disassembled in the Z-axis direction. As shown in FIG. 4, the support member 102 has a cylindrical surface 102a that is convex in the Z-axis direction. The cross-sectional shape of the cylindrical surface 102a in the YZ plane is an arc shape, and the axis defining the cylindrical surface 102a is parallel to the X-axis direction. That is, the center of curvature C of the cylindrical surface 102a is located on the axis. The radius of curvature of the cylindrical surface 102a, that is, the distance r1 from the center of curvature C on the axis to the cylindrical surface 102a is, for example, 10 mm.

The support member 102 has a circular opening 102b penetrating the cylindrical surface 102a in the Z-axis direction, and the semiconductor laser element 30 is attached to the opening 102b. At this time, the semiconductor laser element 30 is opened so that the laser beam is emitted to the convex cylindrical surface side.
02b. Further, the semiconductor laser element 30
Is mounted on the support member 102 such that the major axis direction coincides with the X-axis direction in the beam cross section of the emitted laser beam.

By rotating the support member 102 having such a structure about the axis, the semiconductor laser element 30 can be rotated substantially in the short axis direction of the beam cross section, that is, in the Y axis direction. It is possible to adjust the radiation angle in the short-axis direction in the beam cross section of the emitted laser beam.

The fixing member 10 for receiving the supporting member 102
4 is fixed to the housing 6a of the laser beam transmitting / receiving unit 6. The fixing member 104 has a cylindrical surface 104a that is concave in the Z-axis direction. This cylindrical surface 1
The cross section of the 04a in the YZ plane is arc-shaped, and the axis defining the cylindrical surface 104a is parallel to the X-axis direction. That is, the center of curvature C of the cylindrical surface 104a is located on the axis. The radius of curvature of the cylindrical surface 104a, that is, the distance from the center of curvature C on the axis to the cylindrical surface 104a is r1, which is the same as the radius of curvature of the cylindrical surface 102a of the support member 102, and is 10 mm in this embodiment.

The fixing member 104 has a circular opening 104b penetrating the cylindrical surface 104a in the Z-axis direction. The opening 104 b is provided for guiding a laser beam emitted from the semiconductor laser element 30 attached to the support member 102 to a subsequent optical system such as the beam splitter 32, and an opening formed in the support member 102. It has a larger diameter than the portion 102b.

The concave cylindrical surface 104a of the fixing member 104 having such a structure is formed on the convex cylindrical surface 102a of the support member 102.
a, and by sliding the cylindrical surface 102a along the cylindrical surface 104a, the support member 102 is moved to the cylindrical surface 102a.
It becomes possible to rotate about the axis of a. This makes it possible to substantially rotate the semiconductor laser element 30 in the short-axis direction in the beam section, that is, in the Y-axis direction, and adjust the radiation angle of the emitted laser beam in the short-axis direction in the beam section. It is possible to do. Therefore, it is possible to correct the radiation angle of the laser beam emitted from the semiconductor laser element 30 in the short axis direction, and to make the center of luminance of the laser beam parallel to the optical axis, that is, the Z axis in the short axis direction. Become.

FIGS. 5A and 5B are views showing a state in which the cylindrical surface of the support member is in contact with the cylindrical surface of the fixed member in the adjusting mechanism, and FIG. It is sectional drawing in a plane, (b) is a rear view in an XY plane.

As shown in FIG. 5B, the adjusting mechanism 1
The fixing member 104 is fixed to a housing of a laser beam transmitting / receiving unit (not shown) by a screw 106. At this time, the concave cylindrical surface that receives the support member 102 is released from the housing.

Then, as shown in FIG. 5A, the semiconductor laser device 3 attached to the support member 102
The cylindrical surface 102a of the support member 102 is brought into contact with the concave cylindrical surface 104a of the fixing member 104 such that the reference surface of 0 is perpendicular to the optical axis O.

At this time, it is assumed that the luminance center of the laser beam emitted from the semiconductor laser element 30 has a deviation angle of θ with respect to the optical axis O, as shown in FIG. In this case, as shown in FIG.
The convex cylindrical surface 102a of the supporting member 102 is slid along the concave cylindrical surface 104a of the fixing member 104 around the center of curvature C of the convex cylindrical surface 102a of the second fixing member 104 and the concave cylindrical surface 104a of the fixing member 104. By rotating the support member 102 by θ / 2, the emission angle of the laser beam can be adjusted with respect to the component in the short-axis direction in the beam cross section, and the luminance center of the laser beam and the optical axis O can be adjusted. It is possible to make them coincide.

The optical axis of such a light source is adjusted, for example, by causing a laser beam to be emitted from the semiconductor laser element 30 and making the emitted laser beam coincide with the optical axis O while imaging the emitted laser beam with a CCD camera. Support member 10
2 is achieved.

Then, the support member 102 is adhered to the fixing member 104 with the optical axis O adjusted as described above, so that the support member 102 is fixed as shown in FIGS. 6A and 6B. You.

As shown in FIGS. 7A and 7B, the support member 102 may be fixed to the fixing member 104 by screwing with the optical axis O adjusted. . That is, a pair of screw holes 104c are formed in the fixing member 104 in advance. The support member 10
2, a through hole 102c larger than the diameter of the screw hole 104c is formed in advance at a position substantially corresponding to the position of the screw hole 104c of the fixing member 104. Then, with the optical axis adjusted, the fixing member 104 is screwed into the screw hole 104c of the fixing member 104 with the screw 110 through the through hole 102c of the supporting member 102.
Fixed to

In the above-described embodiment, as shown in FIG. 4, the optical head device supports the light source 30 and mounts the light source 30 on the housing 6a of the laser beam transmitting / receiving unit 6 in a simple manner. A support member 102 having a convex cylindrical surface 102a having one radius of curvature r1 and a fixing member 104 attached to the housing 6a and having a concave cylindrical surface 104a having the same radius of curvature r1 as the support member 102. And

The light source 30 emits an elliptical laser beam in the beam cross section.
The supporting member 10 is arranged such that the major axis direction in the beam cross section is substantially parallel to the axial direction defining the convex cylindrical surface 102a.
2 attached. Then, the cylindrical surface 102a of the support member 102 to which the light source 30 is attached is fixed to the fixing member 10.
By rotating the support member 102 about the axis as a center axis while abutting on the cylindrical surface 104a of No. 4, the radiation angle of the laser beam emitted from the light source 30 in the short-axis direction in the beam cross section can be adjusted.

That is, the mechanism for mounting the light source 30 on the housing 6a can be applied as the adjusting mechanism 100 for adjusting the radiation angle of the laser beam emitted from the light source 30 in the short axis direction.

For this reason, it is possible to correct the deviation of the emission angle of the laser beam emitted from the light source without increasing the number of components, and it is possible to make the luminance center of the laser beam substantially coincide with the optical axis. .

This makes it possible to optimize the shape of the cross section of the laser beam emitted from the light source toward the optical disk, accurately reproduce information recorded on the optical disk, and read information from the optical disk. It becomes possible to record accurately.

In the above-described embodiment, as shown in FIG. 4, the support member 102 is formed to have a single cylindrical surface 102a having a single radius of curvature r1. To the concave cylindrical surface 104a of the fixing member 104.
On the other hand, as long as it can be provided slidably, it is not necessary to form only a single cylindrical surface.

That is, as shown in FIG.
Reference numeral 20 denotes a first cylindrical surface 120a having a first radius of curvature r1 in contact with the concave cylindrical surface 104a of the fixing member 104;
And a second cylindrical surface 120c having a second radius of curvature r2 smaller than the radius of curvature r1. Second
The cylindrical surface 120c has the same center of curvature C as the first cylindrical surface 120a.

As shown in FIG. 9, when the first cylindrical surface 120a comes into contact with the concave cylindrical surface 104a of the fixing member 104, the second cylindrical surface 120c forms a predetermined gap D from the cylindrical surface 104a. It is provided so that

The gap D is desirably 0.3 mm or less in order to dissipate the heat generated by the light source 30 to the fixing member 104 via the support member 120. Note that the second cylindrical surface 120c is not necessarily required to be a cylindrical surface. That is, the first cylindrical surface 120a of the support member 120
When a predetermined gap D can be formed from the cylindrical surface 104a when the contact is made with the concave cylindrical surface 104a of the fixing member 104,
It may be a plane.

With such a structure, the fixing member 10 on the first cylindrical surface 120a of the supporting member 120 is formed.
4 makes it possible to reduce the contact area with the concave cylindrical surface 104a. Thereby, the processing of the first cylindrical surface 120a of the support member 120 is facilitated, and the support member 1
Processing of 20 itself becomes easy.

Even in the case where the support member 120 having such a structure is applied, the deviation of the radiation angle of the laser beam emitted from the light source without increasing the number of parts, similarly to the above-described embodiment. Can be corrected, and the luminance center of the laser beam can be made substantially coincident with the optical axis.

This makes it possible to optimize the shape of the cross section of the laser beam emitted from the light source toward the optical disk, accurately reproduce the information recorded on the optical disk, and write the information to the optical disk. It becomes possible to record accurately.

The radii of curvature of the cylindrical surfaces of the supporting member and the fixing member are determined depending on the adjustment accuracy. That is,
By increasing the radius of curvature, a more precise deviation angle can be adjusted.

[0072]

As described above, according to the present invention, it is possible to correct the deviation of the radiation angle of the light beam radiated from the light source without increasing the number of parts, and to reduce the information recorded on the recording medium. It is possible to provide an optical head device and an adjustment method for the optical head device that can accurately reproduce information and accurately record information on a recording medium.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an optical disk device using an optical head device of the present invention.

FIG. 2 is a schematic diagram illustrating a pickup of an actuator of the optical head device shown in FIG. 1;

FIG. 3 is a schematic diagram illustrating a laser beam transmitting / receiving unit of the optical disk device shown in FIG. 1;

FIG. 4 is a perspective view schematically showing a structure of a mechanism for adjusting a radiation angle of a laser beam emitted from a light source applied to the optical head device.

5A is a cross-sectional view illustrating a state in which a support member is in contact with a fixing member of the adjustment mechanism illustrated in FIG. 4, and FIG. 5B is a cross-sectional view illustrating FIG. FIG. 7 is a rear view of the adjustment mechanism in the state shown in FIG.

FIG. 6A is a cross-sectional view illustrating a state in which a radiation angle is adjusted by the adjustment mechanism illustrated in FIG. 5A;
FIG. 6B is a rear view of the adjustment mechanism in the state shown in FIG.

7A is a cross-sectional view showing a state in which the fixing member and the support member are fixed in a state where the radiation angle is adjusted by the adjusting mechanism, and FIG. 7B is a sectional view of FIG. It is a rear view of the adjustment mechanism in the state shown to (a).

FIG. 8 is a perspective view schematically showing a structure of another support member constituting the adjustment mechanism shown in FIG. 4;

FIG. 9 is a cross-sectional view illustrating a state where the radiation angle is adjusted when the support member illustrated in FIG. 8 is applied as an adjustment mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 2 ... Optical disk apparatus 4 ... Actuator 6 ... Laser beam sending / receiving part 6a ... Housing 12 ... Objective lens 14 ... Pickup 16 ... Guide rail 18 ... Carriage 20 ... Mirror 30 ... Semiconductor laser element (light source) 100 ... Adjustment mechanism 102 ... Support Member 102a: convex cylindrical surface 104: fixing member 104a: concave cylindrical surface 120: support member 120a: first cylindrical surface 120c: second cylindrical surface

Claims (9)

[Claims] A light source that emits a light beam having an elliptical beam cross section; and a light source that is moved along a cylindrical surface having a predetermined radius of curvature so that a light beam emitted from the light source has a short beam cross section. Adjusting means for adjusting the axial radiation angle; condensing means for condensing a light beam emitted from the light source at a predetermined position on a recording surface of a recording medium; and the light reflected by the recording surface of the recording medium. An optical head device comprising: a photoelectric conversion unit that receives a reflected light beam from a recording medium, performs photoelectric conversion on the light beam, and outputs an electric signal having a magnitude corresponding to the light intensity. 2. A light source that emits a light beam having an elliptical beam cross section, a support member having a convex cylindrical surface having a predetermined radius of curvature, and supporting the light source; A fixing member having a concave cylindrical surface having the same radius of curvature as the convex cylindrical surface such that the cylindrical surface is slidable in the short axis direction in the beam cross section; and a light beam emitted from the light source is recorded. Light collecting means for condensing light at a predetermined position on a recording surface of the medium, and a light beam reflected by the recording surface of the recording medium and received by the recording medium, photoelectrically converted, and has a size corresponding to the light intensity. An optical head device, comprising: a photoelectric conversion unit that outputs the electric signal. 3. A light source for emitting a light beam having an elliptical beam cross section, a convex cylindrical surface having a predetermined radius of curvature, an axial direction defining the cylindrical surface, and a short axis direction in the beam cross section. And a support member for supporting the light source so that the light source coincides with the light source, and the same curvature as the convex cylindrical surface such that the convex cylindrical surface of the support member is slidable in the minor axis direction in the beam cross section. A fixing member having a concave cylindrical surface with a radius, a light condensing means for condensing a light beam emitted from the light source at a predetermined position on a recording surface of a recording medium, and the light reflected by the recording surface of the recording medium. An optical head device comprising: a photoelectric conversion unit that receives a reflected light beam from a recording medium, performs photoelectric conversion on the light beam, and outputs an electric signal having a magnitude corresponding to the light intensity. 4. A light source for emitting a light beam having an elliptical beam cross section, a first cylindrical surface having a first radius of curvature and a convex surface having a second radius of curvature smaller than the first radius of curvature. A support member having a second cylindrical surface, and supporting the light source such that an axial direction defining the first and second cylindrical surfaces coincides with a short axis direction in the beam cross section; and a convex shape of the support member. Has a concave cylindrical surface having the same first radius of curvature as the first cylindrical surface so that the first cylindrical surface is slidable in the short axis direction in the beam cross section. A fixing member that forms a gap between a surface and the concave cylindrical surface; a light condensing unit that condenses a light beam emitted from the light source at a predetermined position on a recording surface of a recording medium; Light beam reflected from the recording medium reflected by the recording surface An optical head device, comprising: a photoelectric conversion unit that receives a light beam, photoelectrically converts the light, and outputs an electric signal having a magnitude corresponding to the light intensity. 5. A light source for emitting a light beam having a beam cross section of an elliptical shape, a first cylindrical surface having a first radius of curvature and a convex surface having a second radius of curvature smaller than the first radius of curvature. A support member having a second cylindrical surface, and supporting the light source such that an axial direction defining the first and second cylindrical surfaces coincides with a short axis direction in the beam cross section; and a convex shape of the support member. Has a concave cylindrical surface having the same first radius of curvature as the first cylindrical surface so that the first cylindrical surface is slidable in the short axis direction in the beam cross section. A fixing member that forms a gap of 0.3 mm or less between a surface and the concave cylindrical surface; and a light condensing unit that condenses a light beam emitted from the light source at a predetermined position on a recording surface of a recording medium. The recording medium reflected on a recording surface of the recording medium An optical head device, comprising: a photoelectric conversion unit that receives a light beam reflected from a body, photoelectrically converts the light beam, and outputs an electric signal having a magnitude corresponding to the light intensity. 6. A light source for emitting a light beam having an elliptical beam cross section, a convex cylindrical surface having a predetermined radius of curvature, an axial direction defining the cylindrical surface, and a short axis direction in the beam cross section. And a support member for supporting the light source so that the light source coincides with the light source, and the same curvature as the convex cylindrical surface such that the convex cylindrical surface of the support member is slidable in the minor axis direction in the beam cross section. A fixing member having a concave cylindrical surface with a radius, bonding means for bonding the support member to the fixing member in a state in which a luminance center of a light beam emitted from the light source coincides with an optical axis; Condensing means for condensing the reflected light beam at a predetermined position on the recording surface of the recording medium; and receiving the reflected light beam from the recording medium reflected by the recording surface of the recording medium, photoelectrically converting the light beam, and Size corresponding to An optical head device comprising a photoelectric conversion means, further comprising an outputting an electric signal. 7. A light source for emitting a light beam having an elliptical beam cross section, a convex cylindrical surface having a predetermined radius of curvature, an axial direction defining the cylindrical surface, and a short axis direction in the beam cross section. And a support member for supporting the light source so that the light source coincides with the light source, and the same curvature as the convex cylindrical surface such that the convex cylindrical surface of the support member is slidable in the minor axis direction in the beam cross section. A fixing member having a concave cylindrical surface with a radius, a screw fixing the support member to the fixing member in a state where the luminance center of the light beam emitted from the light source coincides with an optical axis, and a light emitted from the light source. Focusing means for focusing the light beam at a predetermined position on the recording surface of the recording medium; receiving the reflected light beam from the recording medium reflected by the recording surface of the recording medium, performing photoelectric conversion, and converting the light beam into light intensity. Of the corresponding size An optical head apparatus comprising: the photoelectric conversion means for outputting the electrical signal, a. 8. A light source that emits a light beam having an elliptical beam cross section is moved along a cylindrical surface having a predetermined radius of curvature, and a radiation angle of a light beam emitted from the light source in a short-axis direction in the beam cross section. Adjusting the optical head device. 9. A light source that emits a light beam having an elliptical beam cross section is supported by a supporting member having a convex cylindrical surface having a predetermined radius of curvature, and the convex cylindrical surface of the supporting member is The light beam emitted from the light source is adjusted by sliding the light beam emitted from the light source by sliding on the concave cylindrical surface having the same radius of curvature as the convex cylindrical surface. Wherein the support member is fixed to the fixing member in a state where the luminance center of the optical head coincides with the optical axis.