JP2003141770A - Optical pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain easy positional adjustment of a light source and a collimating lens. SOLUTION: The optical pickup device 31 includes a holding member 37 for holding the light source 32 generally to be prepared and the collimating lens 36, and the light source 32 is provided so that the positions in the parallel and perpendicular directions to an optical axis 39 and the inclined angle with respect to the optical axis 39 are adjustable to be the desired positions and the angle. When the light source 32 is arranged integrally on the holding member 37 together with the collimating lens 36, since the arranging position of the light source 32 with respect to the collimating lens 36 is adjusted and the integral members after the adjustment are mounted on the optical pickup device 31, the light source 32 and the collimating lens 36 are easily incorporated in the optical pickup device 31 without adjusting the arranging position of them, and also the assembling time is reduced, thereby improves the production efficiency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical pickup device for recording or reproducing information on an optical recording medium.

[0002]

2. Description of the Related Art In an optical pickup device, in order to record or reproduce information on or from an optical recording medium, it is necessary to irradiate light emitted from a light source onto a desired position on the optical recording medium. Therefore, the light source is fixed to the optical pickup device in a state in which the arrangement with respect to the optical recording medium and the emission angle of the light are adjusted so that the emitted light can be irradiated to a desired position on the optical recording medium.

FIG. 3 is a partially exploded perspective view showing a simplified structure of a conventional optical pickup device 1. The adjusting means 3 for adjusting the position of the semiconductor laser device 2, which is the light source 2,
It includes a tilt adjustment holder 4, an XY adjustment holder 5, and an adjustment shaft 6. The semiconductor laser device 2 is mounted on a tilt adjustment holder 4 that adjusts the inclination angle of the light emitted from the semiconductor laser device 2 with respect to the optical axis 7. The optical axis 7 is attached to the tilt adjustment holder 4 on which the semiconductor laser device 2 is mounted.
The protruding portion 8 is formed so as to project in the direction. In addition, through holes 9a and 9b penetrating in the optical axis 7 direction are formed near both ends of the tilt adjustment holder 4 in the longitudinal direction.

An XY adjustment holder 5 for adjusting the position in the biaxial directions orthogonal to each other on a plane perpendicular to the optical axis 7 is arranged closer to the optical recording medium than the tilt adjustment holder 4. An adjustment hole 10 that penetrates in the direction of the optical axis 7 is formed in the center of the XY adjustment holder 5. The adjustment hole 10 is formed such that the diameter of the opening formed on the optical recording medium side is smaller than the diameter of the opening formed on the semiconductor laser device 2 side. Therefore, an inclined surface 11 having an inclination angle with respect to the optical axis 7 is formed in a portion of the XY adjustment holder 5 where the adjustment hole 10 is formed. In addition, through holes 12 a and 12 b penetrating in the optical axis 7 direction are formed near both ends in the longitudinal direction of the XY adjustment holder 5.

The semiconductor laser device 2 of the housing 13 arranged closer to the optical recording medium than the XY adjustment holder 5.
On the side surface on the side, the through holes 9a and 9b and the through hole 12 are formed.
Screw holes 14a and 14b are formed at positions corresponding to a and 12b.

With the raised portion 8 of the tilt adjustment holder 4 inserted in the adjustment hole 10 of the XY adjustment holder 5, the adjustment shafts 6a and 6b are inserted into the through holes 9a and 9b and the through holes 12a and 1, respectively.
2b, and the male screw portions formed at the tip end portions of the adjusting shafts 6a, 6b are inserted into the screw holes 14a, 14b.
Screw to b. Before tightening the adjustment shafts 6a and 6b, the raised portion 8 of the tilt adjustment holder 4 and the inclined surface 11 of the XY adjustment holder 5 are slid against the optical axis 7 of the semiconductor laser device 2 mounted on the tilt adjustment holder 4. The angle is adjusted, and further, the XY adjustment holder 5 is moved in the two axial directions orthogonal to each other in the plane perpendicular to the optical axis 7, and the light emitted from the semiconductor laser device 2 is applied to a desired position on the optical recording medium. After the adjustment, the adjustment shafts 6a and 6b are tightened to fix the tilt adjustment holder 4 and the XY adjustment holder 5 to the housing 13.

Since the light emitted from the semiconductor laser device is diffused light, it is necessary to make it parallel light by a collimator lens. Therefore, the arrangement position of the collimator lens with respect to the semiconductor laser device is adjusted.

FIG. 4 is a partial schematic sectional view showing the structure of a conventional optical pickup device 1 in a simplified manner. The adjusting means 16 for adjusting the position of the collimator lens 15 includes a lens holder 17 and a collimator lens adjusting jig 18. The collimator lens 15 is mounted on the lens holder 17, and a groove 19 is formed on the surface of the lens holder 17 in contact with the housing 13 (referred to as a bottom surface for convenience). The lens holder 17 is arranged on a rail (not shown) extending parallel to the direction of the optical axis 7 provided in the housing 13. The collimator lens adjusting jig 18 having a cylindrical shape has a tip portion 2
At 0, a protruding portion 22 protruding in the direction of the axis 21 is formed.
The protrusion 22 also has a cylindrical shape, and the axis 2 of the protrusion 22 is
3 is displaced in the radial direction in the cross section of the collimator lens adjustment jig 18 with respect to the axis 21. The collimator lens adjustment jig 18 is inserted through a through hole 24 formed in the housing 13, and the protruding portion 22 of the tip portion 20 thereof is inserted into the groove 19 formed in the bottom surface of the lens holder 17. By angularly displacing the collimator lens adjusting jig 18 around the axis 21 as shown by the arrow 25, the protrusion 22 orbits around the axis 23, and the lens holder 17
On the rail in the direction of the optical axis 7. As a result, the collimator lens 15 moves in the direction of the optical axis 7, and the arrangement position with respect to the semiconductor laser device 2 is adjusted.

As described above, by operating the tilt and XY adjustment holders 4 and 5 to adjust the mounting positions of the semiconductor laser device 2 and the collimator lens 15, the light emitted from the semiconductor laser device 2 is collimated. The light passes through the lens 15 and is irradiated onto a desired position on the optical recording medium.

[0010]

The adjusting means 3 and 16 for adjusting the positions of the semiconductor laser device 2 and the collimating lens 15 described above have the following problems. The positions of the semiconductor laser device 2 and the collimator lens 15 must be adjusted by operating the tilt adjustment holder 4, the XY adjustment holder 5, and the collimator lens adjustment jig 18, respectively. A large operating procedure and time are required, and the adjusting means 3, 16
However, there is a problem that the device becomes large in size because it requires a storage space.

The adjustable range of the tilt adjustment holder 4 and the XY adjustment holder 5 is limited to the range of the gap formed by the adjustment shafts 6a and 6b and the through holes 9a and 9b and the through holes 12a and 12b. There is a problem that the movement range of each holder 4, 5 is limited and it is difficult to finely adjust the position of the semiconductor laser device 2.

An object of the present invention is to provide an optical pickup device capable of easily adjusting the positions of a light source and a collimating lens.

[0013]

DISCLOSURE OF THE INVENTION The present invention is an optical pickup device for recording or reproducing information on an optical recording medium by means of light, which is arranged between a light source for emitting light and the light source and the optical recording medium. Light collecting means for collecting the light emitted from the light source onto the optical recording medium, light detecting means for detecting the reflected light from the optical recording medium, and light transmitting means arranged between the light source and the light collecting means. A reflecting optical member, a collimator lens arranged between the light source and the optical member to collimate the light emitted from the light source, a holding member for holding the light source and the collimator lens, a light source, a condensing unit, and light detection. Means, an optical member, a collimator lens, and a housing that houses the holding member, and the collimator lens and the light source are mounted on the holding member, thereby forming the collimator lens, the light source, and the holding member. There is a optical pickup apparatus characterized in that it is integrally formed.

According to the invention, the light source and the collimating lens are held integrally by the holding member. Therefore, when the light source is integrally provided with the collimator lens on the holding member, the arrangement position of the light source with respect to the collimator lens can be adjusted in advance, and the light source, the collimator lens, and the holding member can be used as an integrated member after adjustment. Since the optical pickup device is mounted on the pickup device, it is possible to shorten the assembling time and improve the production efficiency without adjusting the arrangement position of the light source when assembling the optical pickup device. Further, since it is not necessary to always provide the optical pickup device with the adjusting means for adjusting the arrangement position of the light source with respect to the collimator lens, the device can be downsized.

The present invention is also characterized in that the light source mounted on the holding member is adjustable so that the positions of the light emitted from the light source in the directions parallel and perpendicular to the optical axis are at desired positions. And

According to the present invention, the light source is adjustably provided so that the positions in the directions parallel and perpendicular to the optical axis are the desired positions. This makes it possible to adjust the irradiation direction of the light emitted from the light source and the focus position, so that the light can be irradiated to a desired position on the optical recording medium.

Further, the present invention is characterized in that the light source mounted on the holding member is adjustably provided so that an inclination angle with respect to the optical axis becomes a desired angle.

According to the present invention, the light source is provided so that the inclination angle with respect to the optical axis can be adjusted to a desired angle. As a result, the center of the intensity distribution can be moved to the center of the light spot of the emitted light to correct the deviation, so that it is possible to irradiate the optical recording medium with a light spot having no unevenness in the intensity distribution. It will be possible.

The present invention further includes adjusting means for adjusting the position of the light source mounted on the holding member in the directions parallel and perpendicular to the optical axis and the tilt angle with respect to the optical axis, and the adjusting means is integrated. Collimating lens,
It is characterized in that it is provided so as to be attachable to and detachable from the holding member and the light source.

According to the present invention, it is possible to easily adjust the position of the light source in the directions parallel and perpendicular to the optical axis and the inclination angle with respect to the optical axis by the adjusting means, and the adjusting means is integrally configured. Since it is attachable to and detachable from the collimator lens, the holding member, and the light source, it can be detached after adjusting the position and angle of the light source. This reduces the number of members that make up the optical pickup device,
It becomes possible to reduce the size of the device.

Further, the invention is characterized in that the holding member for holding the light source and the collimating lens is provided in the housing so as to be angularly displaceable around the optical axis.

According to the present invention, since the holding member can be angularly displaced about the optical axis, the light diffracted by the diffraction grating can be applied to a desired position on the optical recording medium.

[0023]

1 is a perspective view showing a simplified configuration of an optical pickup device 31 according to an embodiment of the present invention, and FIG. 2 is a partial schematic sectional view of the optical pickup device 31. As shown in FIG. The optical pickup device 31 includes a light source 32 for emitting light, a condensing unit 33 arranged between the light source 32 and the optical recording medium for condensing the light emitted from the light source 32 on the optical recording medium, and an optical recording device. The light detecting means 34 for detecting the reflected light from the medium, the optical member 35 arranged between the light source 32 and the light collecting means 33 for transmitting and reflecting the light, and the light detecting means 34 are arranged between the light source 32 and the optical member 35. A collimating lens 36 that collimates the light emitted from the light source 32 into parallel light; a holding member 37 that holds the light source 32 and the collimating lens 36;
And a housing 38 that houses each member 32, 33, 34, 35, 36, 37.

The light source 32 is, for example, the semiconductor laser device 3.
2 and the light emitted from the semiconductor laser device 32 is applied to the optical recording medium. The semiconductor laser device 32 is adjustably provided so that the positions of the emitted light in the directions parallel and perpendicular to the optical axis 39 are at desired positions. Further, the semiconductor laser device 32 is adjustably provided so that the inclination angle with respect to the optical axis 39 becomes a desired angle.

The collimator lens 36 collimates the light emitted from the semiconductor laser device 32 into parallel light. Holding member 37
Is a member having a cylindrical shape and made of metal. The collimating lens 36 is attached to one end 40 and the through hole 42 is formed in the other end 41. The holding member 37 has a center of a through hole 44 formed in an end surface 43 (referred to as a mounting surface 43 for convenience) located at the other end of the housing 38, and a through hole 42 formed in the other end 41 of the holding member 37. It is mounted on the inner side of the mounting surface 43 of the housing 38 so that the center of the same is aligned. The semiconductor laser device 32 is inserted into the through hole 44 and the through hole 42, and the collimator lens 36 is inserted.
It is arranged so as to face.

The semiconductor laser device 32 has an adjusting means 45.
Is detachably provided. The adjusting means 45 adjusts the positions in the directions parallel and perpendicular to the optical axis 39.
6 and a goniometer stage 47 that adjusts the inclination angle with respect to the optical axis 39 in the direction of arrow 60, and adjusts the position of the semiconductor laser device 32 with respect to the collimator lens 36.

The position adjustment of the semiconductor laser device 32 with respect to the collimator lens 36 by the adjusting means 45 will be described with reference to FIG. A CCD (Charge Coupled Device) camera 48 is installed at a position on the optical axis 39 which is 500 mm away from the collimator lens 36 mounted on the holding member 37. The CCD camera 48 receives light emitted from the semiconductor laser device 32 by the CCD element and converts the obtained image signal into an electric signal. The light emitted from the semiconductor laser device 32 passes through the collimator lens 36, is received by the CCD element, and is converted into an electric signal. The obtained electric signal is sent to a CPU (Central Processing Unit). This electrical signal may be stored in memory. C
In response to the signal output from PU, CRT (Cathode-R
The image of the received light spot is displayed on the display means realized by ayTube) or the like, and the light spot diameter, the light receiving position and the intensity distribution are monitored. Next, a CCD camera 49 is installed at a position on the optical axis 39 that is further separated from the collimator lens 36 by 200 mm and 700 mm apart,
The light emitted from the semiconductor laser device 32 is received, and the light spot diameter, the light receiving position, the intensity distribution, etc. are monitored.

Information about two light spots obtained at two different positions on the optical axis 39 is compared, and the position of the semiconductor laser device 32 with respect to the collimating lens 36 is adjusted. For example, collimating lenses 36 to 700
When the light spot diameter of the emitted light received at the position separated by mm is larger than the light spot diameter of the emitted light received at the position separated by 500 mm from the collimator lens 36, the semiconductor laser device 32 is moved by the triaxial stage 46. Move away from. Further, when the light receiving position of the emitted light at a position 500 mm away from the collimator lens 36 and the light receiving position of the emitted light at a position 700 mm apart from each other, the light receiving position of the emitted light at a position 700 mm apart is located at a position 500 mm away. The semiconductor laser device 32 is moved by the triaxial stage 46 in a direction deviated from the light receiving position of the emitted light at. When the center of the intensity distribution of the light spot of the emitted light is displaced from the center of the circle of the light spot, the goniometer stage is moved in the direction opposite to the direction where the center of the intensity distribution of the light spot is displaced from the center of the circle of the light spot. Semiconductor laser device 3 according to 47
The tilt angle of the second optical axis 39 with respect to the optical axis 39 is adjusted.

As a result, the semiconductor laser device 32
Since it is possible to adjust the irradiation direction of the light emitted from and the focal position, it becomes possible to irradiate the light to a desired position on the optical recording medium. Further, since the center of the intensity distribution can be moved to the center of the light spot of the emitted light to correct the deviation, it is possible to irradiate the optical recording medium with a light spot having no unevenness in the intensity distribution.

After adjusting the semiconductor laser device 32 with respect to the position and the inclination angle, the semiconductor laser device 32 and the holding member 37 are bonded and fixed, and the adjusting means 45 is separated from the semiconductor laser device 32. When the semiconductor laser device 32 is integrally provided with the holding member 37 as described above, the arrangement positions of the semiconductor laser device 32 and the collimator lens 36 can be adjusted, so that the semiconductor laser device is assembled when the optical pickup device 31 is assembled. It is possible to shorten the assembly time and improve the production efficiency without adjusting the arrangement position of the 32. Further, since the adjusting means 45 for adjusting the arrangement position of the semiconductor laser device 32 with respect to the collimator lens 36 is provided so as to be detachable from the semiconductor laser device 32 after the adjustment, it is not necessary to be always provided in the optical pickup device 31, and the device can be downsized. can do.

The holding member 37, on which the collimator lens 36 and the semiconductor laser device 32 are mounted, is housed in the housing 38 of the optical pickup device 31. When the semiconductor laser device 32 includes a diffraction grating, the integrated collimator lens 36, the semiconductor laser device 32, and the holding member 37 are housed in the housing 38 and then angularly displaced around the optical axis 39 to adjust the irradiation position of the diffracted light. adjust. This allows the light diffracted by the diffraction grating to be applied to a desired position on the optical recording medium.

The optical recording medium has a diameter of 8 cm or 12c.
It has a thin disk-like shape of m, and is formed, for example, by vapor-depositing aluminum on the surface of a polycarbonate substrate and covering the vapor-deposited aluminum layer with a resin protective film. Optical recording media include, for example, CDs (Compact Discs) and DVDs.
(Digital Versatile Disc), etc., and is widely used as a recording medium that can be randomly accessed, is easy to handle, and can record a large amount of information.

The light collecting means 33 includes a raising mirror 50 and an objective lens 51. The raising mirror 50 is the optical member 3
The light transmitted through 5 is reflected toward the objective lens 51, and the light reflected from the optical recording medium and transmitted through the objective lens 51 is reflected toward the optical member 35. The objective lens 51 focuses incident light on the information recording surface of the optical recording medium and forms a light spot on the information recording surface.

The optical member 35 is, for example, a beam splitter 35, which transmits the light emitted from the semiconductor laser device 32 in the direction of the rising mirror 50 and reflects the light reflected from the optical recording medium in the direction of the light detecting means 34. Reflect to. The light detecting means 34 receives the reflected light from the optical recording medium, converts it into a current corresponding to the amount of light, and obtains a detection signal of the reflected light.
The positions of the members 34, 35, 50, 51 are adjusted and housed in the housing 38, and the optical pickup device 31 is configured.

The light emitted from the semiconductor laser device 32 is collimated by the collimator lens 36, passes through the beam splitter 35, and is reflected by the rising mirror 50. The reflected light enters the objective lens 51,
It is focused on a desired position on the optical recording medium. The reflected light from the optical recording medium passes through the objective lens 51 and the rising mirror 5
Reflected by 0. The light incident on the beam splitter 35 is reflected and received by the light detecting means 34 to obtain a detection signal.

[0036]

As described above, according to the present invention, when the light source and the collimating lens are integrally provided on the holding member, the arrangement position of the light source with respect to the collimating lens is adjusted, and the adjusted integral member is used as the optical pickup. Since it is mounted on the device, it is possible to shorten the assembly time of the optical pickup device and improve the production efficiency. Further, since it is not necessary to always provide the optical pickup device with adjusting means for adjusting the arrangement position of the light source, the device can be downsized.

Further, according to the present invention, the light source is provided so that the position in the direction parallel to and perpendicular to the optical axis and the inclination angle with respect to the optical axis can be adjusted to the desired position and angle. It is possible to irradiate a desired light spot on the light spot having a uniform intensity distribution.

Further, according to the present invention, the position of the light source in the directions parallel and perpendicular to the optical axis and the inclination angle with respect to the optical axis can be easily adjusted by the adjusting means.

Further, according to the present invention, since the holding member for holding the collimator lens and the light source can be angularly displaced about the optical axis, the light diffracted by the diffraction grating is applied to a desired position on the optical recording medium. can do.

[Brief description of drawings]

FIG. 1 is a perspective view showing a simplified configuration of an optical pickup device 31 according to an embodiment of the present invention.

2 is a partial schematic sectional view of an optical pickup device 31. FIG.

FIG. 3 is a partially exploded perspective view showing a simplified configuration of a conventional optical pickup device 1.

FIG. 4 is a partial schematic cross-sectional view showing a simplified configuration of a conventional optical pickup device 1.

[Explanation of symbols]

31 Optical pickup device 32 light sources 33 light collecting means 34 Light detecting means 35 Optical member 36 Collimating lens 37 holding member 38 housing

Claims (5)

[Claims] 1. An optical pickup device for recording or reproducing information on or from an optical recording medium by light, wherein a light source for emitting light, and light emitted from the light source disposed between the light source and the optical recording medium. A light collecting means for collecting light on the recording medium, a light detecting means for detecting reflected light from the optical recording medium, an optical member arranged between the light source and the light collecting means for transmitting and reflecting light, A collimator lens that is arranged between the optical member and collimates the light emitted from the light source, a holding member that holds the light source and the collimator lens, a light source, a condensing unit, a light detecting unit, an optical member, and a collimator. A collimating lens, a light source, and a holding member are integrally configured by mounting the collimating lens and the light source on the holding member, the housing including a lens and a holding member. Optical pickup device, characterized in that. 2. The light source mounted on the holding member is provided so as to be adjustable so that the positions of the light emitted from the light source in the directions parallel and perpendicular to the optical axis become desired positions. Item 1. The optical pickup device according to item 1. 3. The light source mounted on the holding member is provided so as to be adjustable so that an inclination angle with respect to the optical axis becomes a desired angle.
The optical pickup device described. 4. The adjusting means further includes adjusting means for adjusting a position of a light source mounted on the holding member in a direction parallel to and perpendicular to the optical axis, and an inclination angle with respect to the optical axis. The optical pickup device according to any one of claims 1 to 3, wherein the optical pickup device is detachably attached to the collimator lens, the holding member, and the light source. 5. The optical pickup according to claim 1, wherein the housing is provided with the holding member that holds a light source and a collimator lens so as to be angularly displaceable around the optical axis. apparatus.