JPH05189791A - Separate type optical pickup device - Google Patents

Abstract

PURPOSE:To surely and easily adjust optical axes. CONSTITUTION:Light introduced into a movable optical system 9 through a tracking mirror 8 is deflected by a deflecting prism 17; The inclination of the optical axis (a) of a pencil of emergent light in two directions is adjusted by turning a deflecting member adjusting mechanism 18 contg. a spherical seat 19, etc., and supporting the deflecting prism 17 so that the prism 17 can turn on its deflecting point P. The position of the optical axis (c) of light incident on an object lens 11 is adjusted by moving an emergent optical system 2 in two directions meeting at right angles to each other with an optical axis adjusting mechanism.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a separation type optical pickup device applied to an optical disk drive or the like.

[0002]

2. Description of the Related Art An example of a conventional separation type optical pickup device will be described with reference to FIGS.

In the output optical system 2 of the fixed optical system 1,
The light emitted from the semiconductor laser 3 is made into a parallel light flux by the coupling lens 4, and the polarization beam splitter 5,
The light is sequentially transmitted through the quarter-wave plate 6 and is incident on the deflection prism 7 which is a deflection member. The light beam deflected by the deflecting prism 7 enters the tracking mirror 8, is deflected again by the tracking mirror 8, is emitted from the fixed optical system 1, and is guided into the moving optical system 9.

The light incident on the moving optical system 9 is deflected by a deflecting prism 10 as a deflecting member and is incident on an objective lens 11, whereby a minute light spot is formed on the surface of an optical disc 12 which is an optical information recording medium. Formed as
Information is recorded as is known.

The reflected light from the optical disk 12 is
The light beam is collimated by the objective lens 11, is deflected by the deflection prism 10, and is guided again into the fixed optical system 1. The light guided into the fixed optical system 1 is the tracking mirror 8,
After being sequentially deflected by the deflecting prism 7, the light enters the polarization beam splitter 5 via the quarter-wave plate 6. Since the light incident on the polarization beam splitter 5 is a light beam emitted from the semiconductor laser 3 and its deflection direction is rotated by 90 °, it is deflected by the polarization beam splitter 5 and enters the signal detection optical system 13. Be guided.

The light guided into the signal detection optical system 13 is condensed by the condenser lens 14 and passes through the cylindrical lens 15 to become astigmatism-generated light.
The light receiving element 16 detects the reproduction signal of information, the focus error signal, and the tracking error signal by the known method.

In such a separated type optical pickup device, a tracking actuator (not shown) for adjusting the tracking mirror 8 is provided in the fixed optical system 1, and an objective lens is provided in the moving optical system 9. A focus actuator (not shown) that drives and adjusts 11 in the optical axis direction is provided.

[0008]

In the above conventional separation type optical pickup device, generally, the optical axis a of the light beam emitted from the fixed optical system 1 to the moving optical system 9 is moved by the moving optical system 9. If the state is not exactly parallel to the direction, the optical axis b of the light beam incident on the light receiving element 16 will be displaced depending on the seek position of the moving optical system 9.

After the optical axis a of the light emitted from the fixed optical system 1 is deflected by the deflection prism 10, the objective lens is
If it does not pass through the center of 11, the light receiving element
Offset occurs in the tracking error signal detected in 16.

From the above, the optical axis a of the light beam emitted from the fixed optical system 1 to the moving optical system 9 is
It is necessary to make adjustments so as to be parallel to the moving direction of and to pass through the center of the objective lens 11.

Therefore, in the conventional art, a tracking actuator is used and the tracking mirror 8 is moved to the direction indicated by arrows A and B.
By adjusting the direction, the optical axis c incident on the objective lens 11 can be adjusted in the X axis direction, and the optical axis a emitted from the fixed optical system 1 can be adjusted around the Y axis.
Further, in this case, the Y of the optical axis c entering the objective lens 11 is
As an adjustment method in the axial direction, a method of integrally adjusting the emission optical system 2 including the semiconductor laser 3 and the coupling lens 4 in the Y-axis direction is used, and the optical axis a emitted from the fixed optical system 1 is adjusted. As a method of adjusting around the Z axis, a method of adjusting the semiconductor laser 3 in the Y axis direction with respect to the coupling lens 4 is used.

However, in such an optical axis adjusting method, since the adjusting mechanism is directly provided in the tracking actuator for driving the tracking mirror 8, there is a problem that the tracking actuator becomes large.

Moreover, in such an adjusting method, the tilt and position of the optical axis c incident on the objective lens 11 and the optical axis a emitted from the fixed optical system 1 and the adjustment in the two X- and Y-axis directions are performed. Must be adjusted elsewhere. For this reason, the respective adjustments interfere with each other, and if the tilts in one direction are adjusted and then the tilts in the other direction are adjusted, the tilt in the first direction will shift again.

It is an object of the present invention to provide a separation type optical pickup device which can surely and easily adjust the optical axis.

[0015]

In order to achieve the above object, the first means of the present invention is to reproduce by using reflected light from an emission optical system including a semiconductor laser and a coupling lens and an optical information recording medium. A fixed optical system including a signal detection optical system that detects a signal, a focus error signal, and a tracking error signal, and light emitted from the fixed optical system is formed as a minute light spot on the optical information recording medium. In a separation type optical pickup device comprising a moving optical system including an objective lens and a tracking mirror for performing a tracking operation on a light spot formed by the objective lens, the moving optical system via the tracking mirror in the fixed optical system. A deflecting member for deflecting the light guided to the system and supporting the deflecting member so as to be rotatable around its deflection point. The adjustment mechanism is provided, the emitted light beam towards the moving optical system is emitted from the fixed optical system, characterized in that a emission light axis adjustment mechanism for moving in a direction perpendicular to the emission optical axis.

The second means of the present invention is to detect a reproduction signal, a focus error signal and a tracking error signal by using the emission optical system including the semiconductor laser and the coupling lens and the reflected light from the optical information recording medium. A fixed optical system including a signal detection optical system for performing the movement, a movable optical system including an objective lens that forms light emitted from the fixed optical system as a minute light spot on the optical information recording medium, and the objective lens In the separation-type optical pickup device including a tracking mirror for performing a tracking operation on a light spot formed by, a deflection member for deflecting light guided to the moving optical system via the tracking mirror is provided in the fixed optical system. , A deflection member adjusting mechanism for rotatably supporting the deflection member about its deflection point is provided, and the fixed optical system is provided with a small amount. Movable portion including Kutomo emitting optical system is formed, characterized in that an adjusting mechanism for movably supporting the movable portion in the orthogonal plane with respect to the emission optical axis of the light beam emitted from said semiconductor laser.

Further, the third means of the present invention is to detect a reproduction signal, a focus error signal and a tracking error signal by using reflected light from an emission optical system including a semiconductor laser and a coupling lens and an optical information recording medium. A fixed optical system including a signal detection optical system for performing the movement, a movable optical system including an objective lens that forms light emitted from the fixed optical system as a minute light spot on the optical information recording medium, and the objective lens In a separate type optical pickup device including a tracking mirror for performing a tracking operation on a light spot formed by, a deflection member for deflecting light guided to the moving optical system via the tracking mirror,
A gimbal spring that is rotatable about at least two shafts passing near the deflection point is adjustably supported, and the position-adjusted adjusting member is fixedly held to a fixed base.

[0018]

According to the above-mentioned first means, the deflection member adjusting mechanism adjusts the "tilt" of the optical axis emitted from the fixed optical system in two directions, and also adjusts the outgoing optical axis provided in the fixed optical system. "Position" of the optical axis incident on the objective lens by the mechanism 2
Since the direction can be adjusted, it is not necessary to directly provide an optical axis adjusting mechanism on the tracking actuator as in the conventional case, which enables downsizing and simplification of the tracking actuator. The interference of axis adjustment is reduced, and the adjustment work can be simplified.

According to the second means, the "tilt" of the optical axis emitted from the fixed optical system can be adjusted by the deflecting member adjusting mechanism, and the movable portion including the emitting optical system can be adjusted by the adjusting mechanism. The “position” of the optical axis incident on the objective lens can be adjusted by adjusting the movement in a plane orthogonal to the outgoing optical axis of the outgoing light flux, and thus the “tilt” and “position” of the optical axis Since each can be adjusted at one adjustment point, interference of the optical axis adjustment is reduced, and the adjustment work can be simplified.

Further, according to the third means, the tilt of the optical axis emitted from the fixed optical system is adjusted by using the gimbal spring. Since the force acting at the time of adjustment is only the reaction force due to the deformation of the zirbal spring, it can move extremely smoothly even with a slight rotation, and the adjustment work can be performed accurately and easily.

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a side view of an embodiment of the present invention, and FIG. 2 is a plan view of this embodiment. The same members as those described in the above-mentioned conventional technique (FIGS. 6 and 7) are designated by the same reference numerals, and the description thereof will be omitted.

The light emitted from the semiconductor laser 3 in the emission optical system 2 is polarized beam splitter 5 and quarter wave plate 6.
Are sequentially transmitted and deflected by the tracking mirror 8. On the optical path of the light deflected by the tracking mirror 8, a deflection prism 17 which is a deflection member is arranged. The deflection prism 17 is supported by a deflection member adjusting mechanism 18 so as to be rotatable about its deflection point P. In this case, the deflection member adjusting mechanism 18 is configured by using a spherical seat 19 having the deflection point P as a center.

Further, the emission optical system 2 including the semiconductor laser 3 and the coupling lens 4 causes the emission light flux emitted from the semiconductor laser 3 to be directed in a plane orthogonal to the emission optical axis by an emission optical axis adjusting mechanism (not shown). You can move to A (double arrow).

In such a configuration, the "tilt" of the optical axis a of the light beam emitted from the fixed optical system 1 is the deflection prism 17
Is rotated around the deflection point P to rotate around the Y-axis, Z
It becomes possible to adjust in each axial direction around the axis. Also,
The “position” of the optical axis c incident on the objective lens 11 can be adjusted by moving the entire emission optical system 2 in two directions perpendicular to the emission optical axis d by the emission optical axis adjusting mechanism.

Therefore, it is not necessary to directly provide an optical axis adjusting mechanism to a tracking actuator (not shown) for driving and controlling the tracking mirror 8, which makes it possible to reduce the size and simplification of the entire optical system. Becomes

In other words, the adjustment of the optical axis a emitted from the fixed optical system 1 in the two directions of "tilt" can be performed by rotating the deflection prism 17 about the deflection point P. In addition, the optical axis c entering the objective lens 11
The adjustment of the "position" in the two directions can be performed by moving the entire emission optical system 2 in two directions perpendicular to the emission optical axis d by using the emission optical axis adjustment mechanism.

As described above, since it is not necessary to provide the tracking actuator with the optical axis adjusting mechanism as in the conventional case, the tracking actuator can be miniaturized and simplified. Since the “inclination” and “position” of the axes a and c can be adjusted at one adjustment point respectively, the interference of the optical axis adjustment is reduced compared to the conventional one, and the adjustment work can be further simplified. You can

The adjustment of the "position" of the optical axis c incident on the objective lens 11 is not limited to the method of using the emission optical axis adjusting mechanism as in the above embodiment, and for example, the emission optical The system 2 is a movable part (not shown), and the movable part is provided in a part other than the tracking actuator.
You may make it adjust by the adjustment mechanism which is not shown in figure.

FIG. 3 is a block diagram showing the details of the deflecting member adjusting mechanism in FIG. 1. The deflecting prism 17 is fixed to the upper portion of a holder 20 having a spherical seat 19. The holder 20 is supported by adjusting screws 22 at three positions (two positions are shown in the figure) of the substrate 21, and the spherical seat 19 is supported by a chamfered portion 24 of a receiving hole 23 formed in the upper portion of the base 21. ing.

For adjustment, the holder 20 is rotated around the deflection point P of the deflecting prism 17 by tightening or loosening each adjusting screw 22, and the adjusting screw 22 is tightened and fixed at an appropriate position. That is done.

FIG. 4 is a perspective view showing the structure of another deflecting member adjusting mechanism. The deflecting prism 17 is a torsion spring which is a shaft portion on two axes M and N passing through the deflection point P of the deflecting prism 17. It is fixed to the innermost portion 31 of the gimbal spring 30 which is rotatable around the portions 30a and 30b. Also, the outermost part of the gimbal spring 30
The reference numeral 32 is fixed to the fixed base 33 in the fixed optical system 1.

When a rotational force is applied to the deflection prism 17,
The torsion spring portions 30a and 30b of the gimbal spring 30 are twisted and deformed, and the deflection prism 17 rotates about the deflection point P.
At this time, the acting force is only the reaction force due to the deformation of the gimbal spring 30, so that even a slight rotation can move extremely smoothly.

FIG. 5 is an explanatory view of the adjusting method of the deflecting member adjusting mechanism of FIG. 4, and the deflecting prism 17 is supported on the fixed substrate 33 via the gimbal spring 30 not shown in FIG. On the back surface of the reflecting surface of the deflecting prism 17, a thin rod 35, which is an adjusting jig, is detachably provided.

By moving the end portion of the rod 35 in the X and Y directions in the figure, the deflection prism 17 rotates about the deflection point P. By using an XY stage or the like as the moving method in the X and Y directions, highly accurate adjustment can be performed.

When the deflecting prism 17 is adjusted to an appropriate angle, the shaded portion in the figure, that is, the deflecting prism 17 is shown.
The space between the fixed substrate 33 and the fixed substrate 33 is filled with an adhesive 36 to fix the deflection prism 17 to the fixed substrate 33.

After the adhesive 36 is solidified, if the rod 35 is removed from the deflecting prism 17, an unnecessary external force is not applied to the deflecting prism 17 from the angle adjustment to the fixed holding, so that high adjustment accuracy is maintained. It will be securely held as it is.

Although the tracking mirror 8 is arranged in the fixed optical system 1 in this embodiment, it may be arranged in the moving optical system 9. Further, in the present embodiment, the deflection prism 17 is provided on the optical path between the tracking mirror 8 and the deflection prism 10 of the moving optical system 9, but in addition to this, for example, the tracking mirror 8 and the quarter wavelength plate 6 are provided. It is also possible to provide it on the optical path between them.

[0039]

As described above, according to the first aspect of the invention, the deflection member adjusting mechanism adjusts the optical axis emitted from the fixed optical system in two directions of "inclination", and also the fixed optical system. Since the output optical axis adjusting mechanism provided inside can adjust the "position" of the optical axis incident on the objective lens in two directions, it is not necessary to directly provide the optical axis adjusting mechanism to the tracking actuator as in the conventional case. This makes it possible to reduce the size and simplification of the tracking actuator, and reduce interference of the optical axis adjustment, thereby simplifying the adjustment work.

According to the second aspect of the invention, in addition to adjusting the "tilt" of the optical axis emitted from the fixed optical system by the deflection member adjusting mechanism, a movable portion including the emitting optical system is By adjusting the adjustment mechanism to move within the plane orthogonal to the outgoing optical axis of the outgoing light flux, the "position" of the optical axis entering the objective lens can be adjusted,
As a result, the "tilt" and "position" of the optical axis are set to 1
Since the adjustment can be performed at one adjustment point, the interference of the optical axis adjustment is reduced, and the adjustment work can be simplified.

Further, according to the third aspect of the invention, the tilt of the optical axis emitted from the fixed optical system is adjusted by using a gimbal spring. Since the force acting at the time of adjustment is only the reaction force due to the deformation of the gimbal spring, it can move extremely smoothly even with a slight rotation, and the adjustment work can be performed accurately and easily.

[Brief description of drawings]

FIG. 1 is a side view showing a configuration example of a separation type optical pickup device which is an embodiment of the present invention.

2 is a plan view of the device of FIG. 1. FIG.

3 is a configuration diagram showing details of a deflecting member adjusting mechanism of FIG. 1. FIG.

FIG. 4 is a perspective view showing details of another deflecting member adjusting mechanism.

FIG. 5 is an explanatory diagram of a method of adjusting the mechanism of FIG.

FIG. 6 is a side view showing a configuration example of a conventional separation type optical pickup device.

FIG. 7 is a plan view of the device of FIG.

[Explanation of symbols]

1 ... Fixed optical system, 2 ... Emitting optical system, 3 ... Semiconductor laser, 4 ... Coupling lens, 8 ... Tracking mirror, 9 ... Moving optical system, 12 ... Optical information recording medium, 13
... Signal detection optical system, 17 ... Deflection prism (deflection member),
18 ... Deflection member adjusting mechanism, 30 ... Zirbal spring, 30a, 3
0b ... torsion spring part (shaft part), 33 ... fixed base.

Claims (3)

[Claims] 1. An emission optical system including a semiconductor laser and a coupling lens, and a signal detection optical system for detecting a reproduction signal, a focus error signal, and a tracking error signal using reflected light from an optical information recording medium. Tracking operation of a fixed optical system, a moving optical system including an objective lens for forming light emitted from the fixed optical system as a minute light spot on the optical information recording medium, and a light spot formed by the objective lens. In the separation type optical pickup device including a tracking mirror, a deflecting member for deflecting the light guided to the moving optical system via the tracking mirror is provided in the fixed optical system, and the deflecting member is used for the deflection point. A deflecting member adjusting mechanism that rotatably supports the lens is provided, and the deflecting member adjusting mechanism emits light from the fixed optical system and directs it toward the moving optical system. A separate type optical pickup device comprising an emission optical axis adjusting mechanism for moving the emitted light beam in a direction orthogonal to the emission optical axis. 2. An emission optical system including a semiconductor laser and a coupling lens, and a signal detection optical system for detecting a reproduction signal, a focus error signal, and a tracking error signal using reflected light from an optical information recording medium. Tracking operation of a fixed optical system, a moving optical system including an objective lens for forming light emitted from the fixed optical system as a minute light spot on the optical information recording medium, and a light spot formed by the objective lens. In the separation type optical pickup device including a tracking mirror, a deflecting member for deflecting the light guided to the moving optical system via the tracking mirror is provided in the fixed optical system, and the deflecting member is used for the deflection point. A deflection member adjusting mechanism for rotatably supporting the optical axis is provided, and the fixed optical system is movable including at least the emitting optical system. A separation type optical pickup device, characterized in that an adjusting mechanism is provided for supporting the movable part so as to be movable in a plane orthogonal to an emission optical axis of an emission light beam from the semiconductor laser. 3. An output optical system including a semiconductor laser and a coupling lens, and a signal detection optical system for detecting a reproduction signal, a focus error signal and a tracking error signal by using reflected light from an optical information recording medium. Tracking operation of a fixed optical system, a moving optical system including an objective lens for forming light emitted from the fixed optical system as a minute light spot on the optical information recording medium, and a light spot formed by the objective lens. In the separated optical pickup device including a tracking mirror, a deflection member that deflects the light guided to the moving optical system via the tracking mirror is rotated about at least two shafts passing near the deflection point. A movable gimbal spring adjustably supports the position-adjusted adjustment member against the fixed base. A separate type optical pickup device.