JP2000321510A - Optical axis correcting device and manufacture of optical axis correcting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the optical axis correcting device for correcting the optical axis in an optical spatial transmission device small-sized without lowering the strength. SOLUTION: Rectangualr cuts 713a are formed on the inner peripheral side of the inside ring 713 of a two-axial spring which is rotatably on two orthogonal axes and a mirror holder 90 is so molded by injection as to take the cuts 713a partially in itself. Plastic injected into the cuts 713a form parts connecting the upper and lower parts of the mirror holder 90 which are partitioned by the biaxial spring. Thus, the connection parts connecting the upper and lower parts of the mirror holder 90 are provided inside the inside ring 713, so the radial size of the device can be reduced without decreasing the strength.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical axis correcting device and an optical axis correcting device manufacturing method, and more particularly, to an optical axis correcting device for correcting an optical axis in an optical space transmission device and such an optical axis correcting device. The present invention relates to an optical axis correction device manufacturing method for manufacturing a correction device.

[0002]

2. Description of the Related Art In recent years, research on the practical use of spatial communication using light has been actively conducted due to the shortage of radio wave resources and complicated procedures for setting up a wireless or wired communication line. ing. However, as for the optical space transmission device over a long distance of up to kilometers, a device having sufficient performance has not yet been obtained.

FIG. 11 is a diagram showing a schematic configuration of an optical system portion of an optical space transmission device capable of performing bidirectional optical communication. In this optical space transmission device, the beam of the semiconductor laser 31 modulated based on the transmission signal is converted into parallel light by the lens 32 and is incident on the beam splitter 33. The incident beam is incident on a concave lens 34 on the light input / output side by a beam splitter 33, and the beam expanded by the lens 34 is combined with a lens 3 constituting a main lens unit together with the lens 34.
At 5, the light is converted into parallel light and output to the destination optical space transmission device.

On the other hand, a beam received from the other party is received by a lens 35. This beam is converted into parallel light by a lens 34, passes through a beam splitter 33, and is incident on a beam splitter 36. The beam splitter 36 divides the incident beam into a position detection side and a reception side. The beam distributed to the position detection side is condensed by the lens 37 and enters the position detection sensor 38. The position detection sensor 38 detects the position of the incident light and transmits a detection signal to a control circuit (not shown). On the control circuit side, angle control described later is performed based on the detection signal.

On the other hand, the beam allocated to the receiving side is
The light is condensed by the lens 39 and enters the light receiving element 40. The light receiving element 40 converts the incident beam into an electric signal and sends the electric signal to the receiving circuit as a received signal. On the receiving circuit side, the received signal is demodulated and restored to the original data.

By the way, in order to perform accurate beam transmission / reception with such an optical system, it is necessary that the optical axes of the transmitting side and the receiving side always coincide. However, the optical system is affected by external factors such as wind, vibrations generated inside the device, and furthermore, changes in temperature, etc., causing a shift in the optical axis. In long-distance communication, a slight deviation of the optical axis also hinders communication, so that it is necessary to constantly correct the optical axis.

Therefore, various optical axis correction methods have been conventionally proposed. FIG. 12 is a diagram showing a first example of a conventional optical axis correction device. The optical axis correction device 50 has a lens barrel 51. The optical system shown in FIG. 11 is housed in the lens barrel 51 integrally. The lens barrel 51 is attached to the intermediate ring 52 by an X bearing 54 so as to be rotatable around the X axis. An X-axis motor 53 is fixed to the intermediate ring 52. The rotation of the X-axis motor 53
a, transmitted to the X bearing 54 via the driven gear 54a. Thus, the rotation of the lens barrel 51 around the X axis is controlled.

The intermediate ring 52 is attached to a pedestal 55 by a Y bearing 56 so as to be rotatable around the Y axis. A Y-axis motor 57 is fixed to the pedestal 55.
The rotation of the Y-axis motor 57 is controlled by the driving gear 57a, the driven gear 5
It is transmitted to the Y bearing 56 via 6a. This allows
The rotation of the lens barrel 51 around the Y axis is controlled. X-axis motor 53
The rotation of the Y-axis motor 57 is controlled based on the detection signal of the position detection sensor 38 of the optical system shown in FIG. 11 so that the optical axes always coincide.

FIG. 13 is a diagram showing a second example of a conventional optical axis correction device. This optical axis correction device is interposed in the optical system shown in FIG. 11, and the same components as those in FIG. 11 are denoted by the same reference numerals and description thereof is omitted. Between the beam splitter 33 and the lens 34, as a correction mechanism, an X-axis mirror 61, an X-axis motor 62 for controlling the rotation thereof, a Y-axis mirror 63, and a Y-axis motor for controlling the rotation 64 are provided. An X-axis motor 62 and a Y-axis motor 64 based on a detection signal of the position detection sensor 38
Is controlled, the angles of the X-axis mirror 61 and the Y-axis mirror 63 are controlled. Thereby, the optical axis is corrected.

However, in the configuration shown in FIG. 12, since the entire lens barrel 51 is moved, the inertial mass is large, and the control response is poor. Further, the bearing, the X-axis motor 53, the Y-axis motor 57, and the like need to have high accuracy and high rigidity. Further, the optical axis correction needs to be performed at a very small angle, and a motor or the like without backlash is required.

[0013] The configuration shown in FIG. 13 also requires a mirror and a motor, which complicates the structure and requires a high-precision one without backlash. Therefore, the applicant of the present application has filed Japanese Patent Application No. 10-014533 as an optical axis correcting device for solving these problems.

FIG. 14 is a plan view showing the structure of an optical axis correcting device disclosed in Japanese Patent Application No. 10-014533. Optical axis correction device 7
Reference numeral 0 denotes a configuration in which a biaxial spring 71 is attached to an upper surface of a frame 73 described later. The biaxial spring 71
It is a thin disk-shaped member having elasticity and has three coaxial rings 711, 712, 713. The outermost outer ring 711 is fixed to the frame 73. A gap D11 is provided between the outer ring 711 and the intermediate ring 712. The intermediate ring 712 is connected to the outer ring 711 by Y-axis bridges 71a and 71b so as to be capable of torsional rotation. This allows
The intermediate ring 712 is rotatable around the Y axis with respect to the outer ring 711.

A gap D12 is provided between the innermost inner ring 713 and the intermediate ring 712. The inner ring 713 is connected to the intermediate ring 712 by X-axis bridges 71c and 71d so as to be rotatable. Thus, the inner ring 713 is rotatable around the X axis with respect to the intermediate ring 712. A circular mirror 72 is fixed to the inner ring 713.

FIG. 15 is a sectional view taken along the line X11-X11 in FIG. As described above, the two-axis spring 71
Is fixed to the upper surface of the frame 73. Inner ring 71
A mirror holder 74 is fixed to the lower surface of 3. This mirror holder 74 holds the mirror 72. At this time, the mirror 72 is mounted such that its reflection surface 72a coincides with the center plane of the plate thickness of the biaxial spring 71.

A base plate 7 is provided on the lower end surface of the frame 73.
5 is fixed. Further, a substrate 77 is fixed via an annular spacer 76. On the base plate 75, two X-axis drive mechanisms 78X for rotating the mirror holder 74 around the X-axis and two Y-axis drive mechanisms 78Y for rotating the mirror holder 74 around the Y-axis are provided. ing. The X-axis drive mechanism units 78X and the Y-axis drive mechanism units 78Y are provided at the intersections of the X-axis and the Y-axis, respectively.
That is, they are provided at positions facing each other with the origin interposed therebetween. However, here, one of the X-axis drive mechanisms 78X is not shown because it is on the near side in the drawing.

The Y-axis driving mechanism 78Y is a so-called moving magnet type voice coil motor.
A bobbin 78Ya fixed to the base plate 75, a coil 78Yb wound on the bobbin 78Ya, a yoke 78Yc fixed to the mirror holder 74 side, and a yoke 78Y
and a magnet 78Yd fixed to the inside of c. In the optical axis correction device 70, the mirror holder 7 is controlled by controlling the operations of the two Y-axis driving mechanisms 78Y.
4 controls the rotation angle around the Y axis.

Similarly, the X-axis drive mechanism 78X is provided with a bobbin 7
8Xa, a coil 78Xb, a yoke 78Xc, and a magnet (not shown), whereby the rotation angle of the mirror holder 74 about the X axis is controlled.

On the base plate 75, a Y-axis angle sensor 79 and an X-axis angle sensor (not shown) are fixed. The optical axis correction device 70 controls the X-axis drive mechanism 78X and the Y-axis drive mechanism 78Y based on angle detection signals from the Y-axis angle sensor 79 and the like, and controls the angle of the reflection surface 72a of the mirror 72. I do. This allows
Optical axis correction control is performed.

In such an optical axis correcting device 70, the mirror 72 is mounted such that the reflecting surface 72a of the mirror 72 coincides with the center plane of the plate thickness of the biaxial spring 71. Therefore, even if the mirror 72 rotates, its position in the Z-axis direction does not change.

In the example shown in FIG. 15, a so-called moving magnet type voice coil motor is used as the X-axis drive mechanism 78X and the Y-axis drive mechanism 78Y, but as shown in FIG. It is also possible to use a moving coil type voice coil motor.

In the example shown in FIG. 16, the arrangements of the X-axis drive mechanism 78X and the Y-axis drive mechanism 78Y are upside down as compared to the case of FIG. That is, in the Y-axis drive mechanism 78Y, the bobbin 78Ya and the coil 78Yb
Are moved from the base plate 75 to the mirror holder 74 side, and the yoke 78Yc and the magnet 78Yd are moved from the mirror holder 74 to the base plate 75. The X-axis drive mechanism 78X has the same configuration.

Since the mass of the coil is generally smaller than that of the magnet, the inertial mass of the movable portion can be reduced, and the response of the mirror 72 can be improved.

In the example shown in FIGS. 15 and 16,
Biaxial spring 71, frame 73 and biaxial spring 7
Each of the mirror holder 1 and the mirror holder 74 is adhered by an adhesive, but these may be joined by screws as shown in FIG.

In FIG. 17, the outer ring 711 of the biaxial spring 71 is fixed to the frame 73 by screws 73c. The inner ring 713 of the biaxial spring 71 is fixed to the mirror holder 74 by a screw 72d. Other configurations are the same as those in FIG.

FIG. 18 is a front view of the example shown in FIG. As shown in this figure, the outer ring 711 has a total of 6
It is fixed to the frame 73 by the screws 73c. The inner ring 713 is fixed to the mirror holder 74 by a total of four screws 72d.

FIG. 19 shows the mirror holder 74 shown in FIG.
It is a front view which shows the detail of. As shown in this figure, the mirror holder 74 has holes 74a to 74d into which screws 72d are inserted.
74d are formed. At the center thereof, a hole 74e on which the mirror 72 is placed is formed.

According to such a configuration, during assembly or operation of the apparatus, the two-axis spring 7 is used for some reason.
In the case where 1 has been damaged, the damaged portion can be easily replaced, so that the workability can be improved.

The optical axis correcting device shown in FIGS. 15 and 16 (hereinafter referred to as an optical axis correcting device A) is configured such that a mirror 7 is formed by a biaxial spring 71 made of a thin spring material.
2 is rotatably supported with respect to two axes, the mirror 72 is rotationally driven by a voice coil motor, and the optical axis is corrected by using a change in the reflection angle of the mirror 72.

The rotation support portion (hereinafter referred to as a bridge) of the biaxial spring 71 has a reduced swing rigidity so that it can rotate even with a small force of a small motor. Therefore, plastic deformation occurs even with relatively small stress, and it becomes unusable.

The movable part of the optical axis correcting device A is a mirror 7
2. Biaxial spring 71 and mirror 7 as rotation supporting parts
2 is constituted by a mirror holder 74 for positioning and holding, a magnet (magnet yoke) or a coil of a voice coil type motor as an actuator. In the past, all of these parts were assembled using an adhesive.
Therefore, when the two-axis spring 71 is deformed or damaged when assembling the movable part or for some reason while the apparatus is operating, it is difficult to disassemble after bonding. However, there is a problem that other usable portions cannot be reused.

In the movable portion of the optical axis correction device A, 2
The shaft spring 71 is fastened to the mirror holder 74 with an adhesive. However, in this method, it is necessary to fix parts until the adhesive hardens and reaches a practical strength, so that there is a problem that productivity is reduced. Was.

On the other hand, in the optical axis correcting device shown in FIG.
4, a structure in which the two-axis spring 71 is fastened by a screw enables replacement of the two-axis spring 71, and furthermore, sets the screw fastening position of the two-axis spring 71 on the rotation axis, thereby providing a voice coil motor as a mirror driving actuator. The magnet yoke has a nut function.

However, with respect to the optical axis correction device B,
There is a demand for further improving the mirror follow-up performance with respect to "optical axis deviation", and while the biaxial spring 71 can be replaced, it is necessary to accurately position the mirror holder 74 and the biaxial spring 71 during assembly, which is complicated. There was a problem that it is.

Accordingly, the applicant of the present application has filed an optical axis correction device which solves these problems. FIG. 20 is a diagram illustrating a configuration example of the above-described optical axis correction device. In this figure, a biaxial spring 71 is fixed to the upper surface of a frame 73 by screws. The mirror holder 90 is formed on the inner ring 713 by integral molding.

FIG. 20B is an enlarged view of a portion surrounded by a solid line in FIG. The mirror holder 90 is formed by injection molding, and is configured to take in the biaxial spring 71 therein.

The side surface of the mirror 72 is the mirror holder 9.
0 so as to be in close contact with the inner side surface 90d.
c is mounted. At this time, the reflection surface 72 a and the back surface 72 b of the mirror 72 are parallel to the biaxial spring 71.

An annular notch 90a is formed at the upper end inside the mirror holder 90. The mounting surface 90
An annular groove 90b is formed inside c. An adhesive is injected into the notch 90a with the mirror 72 mounted. Thereby, the mirror 72 is securely fixed to the mirror holder 90. Even if the adhesive in the notch 90a flows down from the gap between the mirror 72 and the inner side surface 90d, the adhesive accumulates in the groove 90b.
It can be prevented from flowing to the c side. Thereby, the mirror 7
2 is not adhered to the mounting surface,
Warpage and distortion of the mirror 72 can be prevented.

As described above, if the mirror holder 90 is formed integrally with the inner ring 713, the size and weight of each component can be reduced, and the inertial mass of the movable portion with respect to the rotation axis of the mirror can be reduced. However, the response characteristics of the mirror to the optical axis deviation can be improved.

[0039]

In the above-described method, the two-axis spring 71 is fixed while being sandwiched by the mirror holder 90 as shown in FIG. At this time,
A portion formed above the biaxial spring 71 of the mirror holder 90 and a portion formed below the biaxial spring 71 are connected by a connecting portion 90e which is an inner peripheral portion of the biaxial spring 71.

FIG. 21 is a front view of FIG. In this figure, the hatched portions are portions where the mirror holder 90 sandwiches the biaxial spring 71 (an sandwiching portion). The shaded portion indicates the above-described connecting portion 90e.

The joining strength between the two-axis spring 71 and the mirror holder 90 largely depends on the strength of the mirror holder connecting portion 90e. Therefore, in order to obtain a certain bonding strength, it is necessary to secure a certain width of the mirror holder connecting portion 90e.

However, the mirror holder connecting portion 90e
To secure a certain width of the mirror holder 90,
In addition, the radial size of the two-axis spring 71 is increased, and the mass of the movable part of the optical axis correction device and the moment of inertia with respect to the rotation axis are increased. There was a point.

The present invention has been made in view of such a point, and it is an object of the present invention to provide an optical axis correcting device having high responsiveness while maintaining high intensity.

[0044]

An optical axis correction device for correcting an optical axis in a space optical transmission device, comprising: a mirror for reflecting a laser beam; a holding member for holding the mirror;
A support member configured by a plate-like member that rotatably supports the holding member around a first axis and a second axis on a plane parallel to a reflection surface of the mirror; A rotation mechanism for independently rotating about the second axis, a rotation angle detection mechanism for detecting a rotation angle of each of the mirrors about each axis, the first axis of the mirror, Turning control means for controlling the turning mechanism so that the turning angles about the second axis are respectively desired angles;
And the support member and the holding member are formed by integral molding, and a plurality of notches having a predetermined shape are formed in a portion of the support member where the holding member is formed. An optical axis correction device is provided.

Here, the mirror reflects the laser light.
The holding member holds the subscriber terminal mirror. The support member is formed of a plate-like member, and supports the subscriber terminal device holding member so as to be rotatable about a first axis and a second axis on a plane parallel to the reflection surface of the subscriber terminal device mirror. . The rotation mechanism is configured to independently rotate the subscriber terminal mirror around the first and second axes. The rotation angle detection mechanism detects a rotation angle of each of the subscriber terminal device mirrors around each axis. The rotation control means controls the rotation of the subscriber terminal device so that the rotation angles of the subscriber terminal device mirror around the first axis of the subscriber terminal device and the second axis of the subscriber terminal device become the desired angles. Control the mechanism. The subscriber terminal device support member and the subscriber terminal device holding member are formed by integral molding, and a predetermined shape is formed in a portion of the subscriber terminal device support member where the subscriber terminal device holding member is formed. Have a plurality of notches.

According to the invention, there is provided an optical axis correcting device for correcting an optical axis in an optical space transmission device, wherein a mirror for reflecting a laser beam, a holding member for holding the mirror, A support member configured by a plate-like member that rotatably supports a member around a first axis and a second axis on a plane parallel to the reflection surface of the mirror, and the first and the second mirrors A rotation mechanism for independently rotating about a second axis, a rotation angle detection mechanism for detecting a rotation angle about each axis of the mirror, the first axis of the mirror and the And a rotation control means for controlling the rotation mechanism so that the rotation angles around the two axes are each a desired angle. The support member and the holding member are integrally formed. And the holding member of the support member is formed. In part, the optical axis correcting device, wherein a plurality of holes having a predetermined shape is formed is provided.

Here, the mirror reflects the laser light.
The holding member holds the subscriber terminal mirror. The support member is formed of a plate-like member, and supports the subscriber terminal device holding member so as to be rotatable about a first axis and a second axis on a plane parallel to the reflection surface of the subscriber terminal device mirror. . The rotation mechanism is configured to independently rotate the subscriber terminal mirror around the first and second axes. The rotation angle detection mechanism detects a rotation angle of each of the subscriber terminal device mirrors around each axis. The rotation control means controls the rotation of the subscriber terminal device so that the rotation angles of the subscriber terminal device mirror around the first axis of the subscriber terminal device and the second axis of the subscriber terminal device become the desired angles. Control the mechanism. The support member and the holding member are formed by integral molding, and a plurality of holes having a predetermined shape are formed in a portion of the support member where the holding member is formed.

[0048]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 4 is a diagram showing a schematic configuration of an optical system portion of an optical space transmission device capable of performing bidirectional optical communication including the optical axis correction device of the present embodiment. In this optical space transmission device, a beam modulated based on a transmission signal is output from the light emitting element 1 (for example, a semiconductor laser diode).
The output beam is converged by the lens 2 and is incident on the beam splitter 3 a of the light splitting unit 3. The incident beam is reflected by the beam splitter 3a and emitted to the optical axis correction device 70, and further reflected by the optical axis correction device 70 and directed to the destination optical space transmission device via the convex lens 5. Is output.

On the other hand, the beam received from the other party is received by the lens 5. After being converged by the lens 5, the beam is reflected by the optical axis correction device 70 and enters the light separating unit 3. The incident beam is applied to the beam splitter 3
a and enters the beam splitter 3b. The beam splitter 3b distributes the incident beam to a position detection side and a reception side. The light distributed to the position detection side is collected by the lens 6 and enters the position detection sensor 7. The position detection sensor 7 detects the position of the incident light and transmits a detection signal to a control circuit (not shown). The control circuit performs angle control described later based on the detection signal.

On the other hand, the beam distributed to the receiving side is
The light is condensed by the lens 8 and enters the light receiving element 9. The light receiving element 9 converts the incident beam into an electric signal and sends it to the receiving circuit as a received signal. On the receiving circuit side, the received signal is demodulated and restored to the original data.

In such a system, the rotation angle of the mirror 72 of the optical axis correcting device 70 around two axes, that is, the rotation around the X axis and around the Y axis, based on the detection signal of the position detection sensor 7 Adjust the angle. Thereby, the correction is performed so that the optical axis always passes through a certain path.

Next, a specific configuration example of the optical axis correction device 70 will be described. FIG. 2 is a plan view of the optical axis correction device 70. The optical axis correction device 70 has a configuration in which a biaxial spring 71 is attached to an upper surface of a frame 73 described later. 2
The shaft spring 71 is a thin and elastic disk-shaped member, and has three coaxial rings 711, 712, and 713. The outermost outer ring 711 has a screw 7
Fixed to the frame 73 by 1e to 71j. A gap D11 is provided between the outer ring 711 and the intermediate ring 712. The intermediate ring 712 is connected to the outer ring 711 in a torsionally rotatable manner by Y-axis bridges 71a and 71b formed so as to face each other on the Y-axis with an intersection T1 between the X-axis and the Y-axis therebetween. . As a result, the intermediate ring 712 is
1 is rotatable around the Y axis.

A gap D12 is provided between the innermost inner ring 713 and the intermediate ring 712. The inner ring 713 is connected to the intermediate ring 712 in a torsionally rotatable manner by X-axis bridges 71c and 71d formed so as to face each other across the intersection T1 on the X-axis. Thus, the inner ring 713 is rotatable around the X axis with respect to the intermediate ring 712.
Further, as described later, a plurality of notches are formed in the inner circumference of the inner ring 713, and a mirror holder 90 is formed by integral molding so as to sandwich the notch. Mirror 72
Is fixed.

FIG. 1A is a sectional view taken along the line X11--X11 in FIG. In this figure, a biaxial spring 71
Is fixed to the upper surface of the frame 73 with the screw as described above. The inner ring 713 has a mirror holder 90
Are formed by integral molding.

FIG. 1B is an enlarged view of a portion surrounded by a solid-line circle in FIG. The mirror holder 90 is formed by injection molding, and is configured to take in the biaxial spring 71 therein. FIG.
As is clear from the comparison with FIG.
1 is inserted up to the inside of the mirror holder 90.

FIG. 3 is a diagram showing a detailed configuration example of the biaxial spring 71 and the mirror holder 90. As shown in FIG. 3A, a plurality of rectangular cutouts 713a are formed in a portion of the inner ring 713 that contacts the mirror holder 90.

Since the mirror holder 90 is injection-molded so as to take the notch 713a of the inner ring 713 into the inside thereof, as shown in FIG.
“a” is a connecting portion (filled portion in the drawing), and the other portion is a sandwiching portion (hatched portion in the drawing).

The joining strength between the two-axis spring 71 and the mirror holder 90 is determined by the degree of adhesion between the two-axis spring 71 and the mirror holder 90 and the strength of the connecting part of the mirror holder 90. It depends largely on the area.

Conventionally, in order to obtain the strength of the connecting portion, it is necessary to increase the width of the ring-shaped connecting portion 90e (see FIG. 20B). However, as the width of the connecting portion 90e of the mirror holder 90 increases, the size of the mirror holder 90 in the radial direction increases, and the size of the biaxial spring 71 also increases accordingly. 2-axis spring 7
As described above, the enlargement of 1 leads to an increase in the moment of inertia of the movable part with respect to the rotation axis, and also reduces the responsiveness of the mirror to “optical axis deviation”.

In the present embodiment, the notch 713a is provided in the inner ring 713, and a connecting portion is formed at this portion. Therefore, the size of the mirror holder 90 and the biaxial spring 71 can be increased without increasing the size. The required strength can be secured.

The side surface of the mirror 72 is the mirror holder 9.
0 so as to be in close contact with the inner side surface 90d.
c is mounted. At this time, the reflection surface 72 a and the back surface 72 b of the mirror 72 are parallel to the biaxial spring 71.

An annular cutout 90a is formed at the upper end inside the mirror holder 90. The mounting surface 90
An annular groove 90b is formed inside c. An adhesive is injected into the notch 90a with the mirror 72 mounted. Thereby, the mirror 72 is securely fixed to the mirror holder 90. Even if the adhesive in the notch 90a flows down from the gap between the mirror 72 and the inner side surface 90d, the adhesive accumulates in the groove 90b.
It can be prevented from flowing to the c side. Thereby, the mirror 7
2 is not adhered to the mounting surface,
Warpage and distortion of the mirror 72 can be prevented.

The mirror 72 is processed so that light can be reflected not only on the reflection surface 72a on the front side but also on the back surface 72b. A base plate 75 is fixed to the lower surface of the frame 73. Further, a substrate 77 is fixed via an annular spacer 76. On the base plate 75, two Y-axis drive mechanisms 78Y for rotating the mirror holder 74 around the Y-axis are provided so as to face each other with the Z-axis interposed therebetween. Further, on the base plate 75, two X-axis driving mechanisms 78X that rotate around the X-axis are opposed to each other across the Z-axis, and are shifted by 90 ° from the Y-axis driving mechanism 78Y. It is provided in. Note that, in this example, the one X-axis drive mechanism 78X is omitted from the drawing because it exists before the drawing.

The Y-axis driving mechanism 78Y is a so-called moving magnet type voice coil motor.
A bobbin 78Ya fixed to the base plate 75, a coil 78Yb wound on the bobbin 78Ya, a yoke 78Yc fixed to the mirror holder 74 side, and a yoke 78Y
and a magnet 78Yd fixed to the inside of c. By passing a current through the coil 78Yb wound on the bobbin 78Ya, the magnet 78Yd receives a force in a direction corresponding to the direction of the current, thereby causing the mirror holder 7 to move.
4 rotates around the Y axis. In the optical axis correction device 70, the rotation angle of the mirror holder 74 around the Y axis is controlled by controlling the operations of these two Y axis drive mechanisms 78Y.

The base plate 75 is provided with stoppers (not shown) corresponding to each of the two Y-axis driving mechanism portions 78Y. These stoppers are provided to limit the amount of movement of the yoke 78Yc. The stopper can be adjusted up and down with respect to the base plate 75, so that the amount of movement of the yoke 78Yc can be adjusted.

On the other hand, the X-axis driving mechanism 78X is also
8Xa, a coil 78Xb, a yoke 78Xc, and a magnet (not shown), and another X-axis driving mechanism 78X (not shown) provided at a position facing the magnet has the same configuration. X-axis drive mechanism 78
X also has a stopper (not shown). In the optical axis correction device 70, the X-axis driving mechanism 78X
Is controlled, the rotation angle of the mirror holder 74 around the X axis is controlled.

On the base plate 75, a Y-axis angle sensor 79 and an X-axis angle sensor (not shown) are fixed. The Y-axis angle sensor 79 and the X-axis angle sensor are optical sensors, in which a light emitting element and a light receiving element are provided integrally. Then, the light from the light emitting element is reflected by the back surface 72b of the mirror 72, and the reflected light is detected by the light receiving element, whereby the rotation angle of the mirror 72 around the Y axis and the rotation angle around the X axis are respectively determined. To detect. Optical axis correction device 70
Then, based on the angle detection signals from the Y-axis angle sensor 79 and the X-axis angle sensor, the X-axis drive mechanism 78X
And the Y-axis drive mechanism 78Y to control the angle of the reflection surface 72a of the mirror 72. Thereby, the optical axis correction control is performed.

Next, another example of the structure of the biaxial spring will be described with reference to FIGS. In the example of FIG.
As shown in (A), a plurality of notches 713b are formed alternately on the inner peripheral side of the inner ring 713, and a plurality of notches 713c are formed on the outer peripheral side.

Further, as shown in FIG. 5B, when the mirror holder 90 is formed integrally with the biaxial spring 71, the holding portion (the hatched portion in the drawing) and the rectangular The connecting portions are alternately formed, and the bonding strength of the mirror holder 90 can be secured.

In the example of FIG. 6, as shown in FIG.
A wedge-shaped notch 713 on the inner peripheral side of the inner ring 713
d is formed in plurality. Further, as shown in FIG. 6B, when the mirror holder 90 is formed integrally with the biaxial spring 71, the inner peripheral side of the sandwiching portion (the hatched portion in the drawing) A plurality of wedge-shaped connecting portions are formed, and the bonding strength of the mirror holder 90 can be secured.

In the example of FIG. 7, as shown in FIG.
A plurality of circular holes 713e are formed in the center of the inner ring 713. Further, as shown in FIG. 7B, when the mirror holder 90 is formed by integral molding with the biaxial spring 71, a circular portion is provided at the center of the sandwiching portion (the hatched portion in the figure). The connecting portion is formed, and the bonding strength of the mirror holder 90 can be secured.

In the example of FIG. 8, as shown in FIG.
A plurality of oblong holes 713f are formed in the center of the inner ring 713. As shown in FIG. 8B, the mirror holder 90 is formed integrally with the biaxial spring 71 by molding.
Is formed, an oval connecting portion is formed at the center of the sandwiching portion (the hatched portion in the figure), and the coupling strength of the mirror holder 90 can be secured.

Since the connecting portion of the conventional mirror holder is located on the inner peripheral portion of the inner ring 713, the size of the mirror holder is increased by that amount. However, five types of two-axis springs shown in FIGS. Each has a shape in which the connecting portion of the mirror holder is located on the inner ring 713 of the biaxial spring. Therefore, the size of the mirror holder can be reduced by a dimension corresponding to the width of the conventional mirror holder connecting portion. Further, the conventional biaxial spring has a problem that the connecting portion of the mirror holder 90 is biased only to the inner peripheral portion of the mirror holder 90 and has a thin ring shape, so that this portion is easily damaged. Was. However, in the biaxial spring using the inner ring 713 shown in FIGS. 5 to 8, the connecting portion of the mirror holder 90 is located at a substantially uniform position with respect to the inner ring 713 and the stability is good. The joining strength of the holder can be improved.

The number of notches and holes is shown in FIGS.
It is not limited to the numbers shown in. Also, the shape of the notch or the hole is not limited to such a case,
It may be a notch or square hole.

Next, a configuration example of the second embodiment of the present invention will be described with reference to FIG. By the way, in the case of the optical axis correction device shown in the embodiment shown in FIG. 1, the center of the plate thickness of the biaxial spring 71, that is, the center of rotation, and the optical axis correction surface of the mirror 72 coincide with each other. This is because if the rotation center of the mirror 72 of the optical space transmission device does not coincide with the optical axis correction surface, the rotation of the mirror 72 displaces the optical axis correction surface, for example, the focal length between the main lens and the position detection sensor. This causes a problem that the optical axis deviation cannot be measured accurately.

On the other hand, in an optical space transmission device having an optical system as shown in FIG. 9, the front and rear of the optical axis correction device are parallel light, and the rotation of the mirror 72 causes the optical axis correction surface to be displaced. However, the focal length does not change, so that the rotation center of the mirror 72 does not need to coincide with the optical axis correction surface.

That is, in the optical space transmission apparatus shown in FIG. 9, a concave lens 4 is newly added as compared with the case of FIG. Other configurations are the same as those in FIG. The concave lens 4 constitutes a main lens section together with the lens 5, and enlarges the beam radius of the beam reflected by the mirror 72 and outputs the beam toward the optical space transmission apparatus at the transmission destination.

On the other hand, the beam received from the other party is received by the lens 5. This beam is converted into parallel light by the lens 4, then reflected by the optical axis correction device 70 and enters the light separation unit 3.

According to the above configuration, since the beam incident on the optical axis correction device 70 has a parallel configuration, the position of the reflection surface 72a in the Z-axis direction changes with the rotation of the mirror 72. Does not affect the optical path length of the transmitted / received light.

Therefore, in such a case, the center of rotation of the two-axis spring 71 and the reflecting surface 72a of the mirror 72 do not necessarily have to coincide with each other. It is possible to arrange the mass more evenly.

FIG. 10 shows a configuration example of an embodiment of an optical axis correction device used in such an optical space transmission device. In addition,
In this embodiment, parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and a description thereof will be omitted.

In this embodiment, the mirror holder 110 has a structure protruding from the upper surface of the biaxial spring 71 as compared with the case of FIG. Also, mirror holder 1
The height of the frame 73 is reduced by an amount corresponding to the protrusion of the frame 10 to the outside. Other configurations are the same as those in FIG.

When FIG. 1 is compared with FIG. 10, in the embodiment shown in FIG. 1, the mass of the movable portion is concentrated at the lower portion with respect to the center of the plate thickness of the biaxial spring 71 which is the rotating shaft. On the other hand, in the embodiment shown in FIG.
Is located below the mirror 72, the mirror is arranged above the center of rotation, and the actuator is arranged below the center of rotation, so that the mass distribution of the movable part is equalized and the components of the movable part (for example, , Magnets, etc.) from the center of rotation is reduced, so that the moment of inertia with respect to the rotation axis can be reduced.

As described above, from the viewpoint of the moment of inertia of the movable portion with respect to the rotation axis, the embodiment shown in FIG. 10 has a smaller inertia moment, and has the above-described vibration characteristics, that is, the control in the rotation driving of the mirror. The characteristics can be improved.

Further, by integrating the two-axis spring 71 and the mirror holder 90, the screw fastening portion of the two-axis spring 71 which is necessary in the conventional example shown in FIG. Can be reduced, whereby the width of the first ring is reduced, and as a result, the size of the biaxial spring 71 can be reduced.

Incidentally, even in the optical space transmission apparatus of an optical system which does not use parallel light as shown in FIG.
If the function of correcting the focal length described in Japanese Patent Publication No. 23 is used, an optical axis correcting device as shown in FIG. 10 can be used.

As described above, according to the optical axis correcting device of the present invention, the inner ring 7 of the biaxial spring 71
Since a notch or a hole is formed in 13 and the mirror holder 90 is formed integrally with this portion, the size of the apparatus can be reduced without reducing the strength of the mirror holder 90. It becomes possible.

In addition, since components such as screws are eliminated by integral molding and the size of the device can be reduced as described above, the inertial mass can be further reduced and the response characteristics of the device can be improved. .

[0089]

According to the present invention, there is provided an optical axis correcting apparatus for correcting an optical axis in an optical space transmission apparatus, comprising: a mirror for reflecting a laser beam; a holding member for holding the mirror; A support member constituted by a plate-like member rotatably supporting about a first axis and a second axis on a parallel surface, and a mirror which is independently rotated about the first and second axes. A rotation mechanism, a rotation angle detection mechanism for detecting a rotation angle around each axis of the mirror, and a rotation angle around the first axis and the second axis of the mirror each become a desired angle. A rotation control means for controlling the rotation mechanism,
The support member and the holding member are formed by integral molding, and a plurality of notches having a predetermined shape are formed in a portion of the support member where the holding member is formed, so that the strength of the device is secured. It is possible to reduce the size while doing so.

Further, according to the present invention, in an optical axis correction device for correcting an optical axis in an optical space transmission device, a mirror for reflecting a laser beam, a holding member for holding the mirror, and a holding member are provided. A support member constituted by a plate-like member rotatably supporting a first axis and a second axis on a plane parallel to the reflection surface of the mirror;
A rotation mechanism for independently rotating about the axis of the mirror, a rotation angle detection mechanism for detecting a rotation angle about each axis of the mirror,
Rotation control means for controlling the rotation mechanism so that the rotation angles of the mirror around the first axis and the second axis are respectively the desired angles. The support member and the holding member are In addition to being formed by integral molding, a plurality of holes having a predetermined shape are formed in a portion where the holding member of the support member is formed, so that the size can be reduced while ensuring the strength of the device. Becomes possible.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration example of an embodiment of an optical axis correction device according to the present invention.

FIG. 2 is a plan view of the optical axis correction device shown in FIG.

FIG. 3 is a front view showing a detailed configuration example of the mirror holder shown in FIG. 1;

FIG. 4 is a diagram illustrating a schematic configuration of an optical system portion of an optical space transmission device capable of performing bidirectional optical communication including the optical axis correction device according to the present embodiment.

FIG. 5 is a view showing another detailed configuration example of the mirror holder shown in FIG. 1;

FIG. 6 is a diagram showing another detailed configuration example of the mirror holder shown in FIG. 1;

FIG. 7 is a diagram showing another detailed configuration example of the mirror holder shown in FIG. 1;

FIG. 8 is a diagram showing another detailed configuration example of the mirror holder shown in FIG. 1;

FIG. 9 is a diagram illustrating a configuration example of a second embodiment of the present invention.

FIG. 10 is a cross-sectional view illustrating a configuration example according to a second embodiment of the present invention.

FIG. 11 is a diagram illustrating a schematic configuration of an optical system portion of a conventional optical space transmission device capable of performing bidirectional optical communication.

FIG. 12 is a diagram showing a first example of a conventional optical axis correction device.

FIG. 13 is a diagram showing a second example of a conventional optical axis correction device.

FIG. 14 is a plan view showing a configuration of an optical axis correction device disclosed in Japanese Patent Application No. 10-014533.

FIG. 15 is a sectional view taken along line X11-X11 in FIG. 14;

FIG. 16 is a cross-sectional view illustrating a configuration of an optical axis correction device having a moving coil type voice coil motor.

FIG. 17 is a cross-sectional view illustrating a configuration of an optical axis correction device in which a two-axis spring, a mirror holder, and a frame are joined by screws.

18 is a front view of the optical axis correction device shown in FIG.

19 is a diagram showing a detailed configuration example of a mirror holder of the optical axis correction device shown in FIG.

FIG. 20 is a diagram showing a configuration example of an optical axis correction device in which a two-axis spring and a mirror holder are formed by integral molding.

21 is a front view showing details of a joint portion between a biaxial spring of the optical axis correction device shown in FIG. 20 and a mirror holder.

[Explanation of symbols]

1 ... light emitting element, 3 ... light separating section, 5 ... lens, 7 ...
... Position detection sensor, 9 ... Light receiving element, 70 ... Optical axis correction device, 71 ... Two-axis spring, 72 ... Mirror, 72
a ... reflective surface, 72b ... back surface, 73 ... frame, 74 ...
… Mirror holder, 90a… notch, 90b… groove
78Y: Y-axis drive mechanism, 78X: X-axis drive mechanism, 90: mirror holder, 100: plate-shaped spring material, 1
10. Mirror holder, 711 Outer ring, 712
…… Intermediate ring, 713 …… Inner ring, 713a to 713
13d ... notch, 713e, 713f ... hole

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuhiko Otsuka 6-35 Kita Shinagawa, Shinagawa-ku, Tokyo Sony Corporation F-term (reference) 2H041 AA12 AB14 AC04 AZ02 AZ03 AZ06 2H043 AD02 AD21 5K002 AA05 AA07 BA13 BA21 FA04

Claims (4)

[Claims] 1. An optical axis correcting device for correcting an optical axis in an optical space transmission device, comprising: a mirror for reflecting a laser beam; a holding member for holding the mirror; A support member configured by a plate-like member that rotatably supports around a first axis and a second axis on a plane parallel to the reflection surface; and the mirror around the first and second axes. A rotation mechanism for independently rotating; a rotation angle detection mechanism for detecting a rotation angle of each of the mirrors around each axis; and a rotation of the mirror around the first axis and the second axis. Rotation control means for controlling the rotation mechanism so that each of the movement angles becomes a desired angle. The support member and the holding member are integrally formed, and the support member In the portion where the holding member is formed, Optical axis correcting device, wherein a plurality of notches are formed to have a shape. 2. The device according to claim 1, wherein the holding member is formed by injection molding on the support member.
The optical axis correction device as described in the above. 3. An optical axis correcting device for correcting an optical axis in an optical space transmission device, comprising: a mirror for reflecting a laser beam; a holding member for holding the mirror; A support member configured by a plate-like member that rotatably supports around a first axis and a second axis on a plane parallel to the reflection surface; and the mirror around the first and second axes. A rotation mechanism for independently rotating; a rotation angle detection mechanism for detecting a rotation angle of each of the mirrors around each axis; and a rotation of the mirror around the first axis and the second axis. Rotation control means for controlling the rotation mechanism so that each of the movement angles becomes a desired angle. The support member and the holding member are integrally formed, and the support member In the portion where the holding member is formed, Optical axis correcting device, wherein a plurality of holes are formed to have a shape. 4. The holding member is formed by injection molding on the support member.
The optical axis correction device as described in the above.