JP4633484B2 - Optical element support mechanism - Google Patents

Description

  The present invention relates to a support mechanism for an optical element capable of adjusting the position and angle of the optical element. For example, information is recorded and / or reproduced on an optical communication device such as an optical antenna, an optical deflector, an optical coupler, or an optical recording medium (for example, a magneto-optical disk drive, CD-ROM, DVD, optical card, etc.) The present invention relates to a support mechanism for an optical element that can be suitably used for an information recording apparatus.

Conventionally, for example, in an optical deflector of an optical communication device, an optical element such as a reflecting mirror or a condensing lens is arranged with high accuracy in the device to deflect or collect the light, and its position and orientation Need to hold. Therefore, the optical element is generally supported and fixed on a support mechanism. In order to prevent distortion of the optical surface of the supported optical element, it is known that the optical element is restrained by point support at six different positions. This is based on the rigid body having 6 degrees of freedom.
For example, the conventional technique of Patent Document 1 describes a Kelvin clamp, which is a kind of kinematic mount, as such a support mechanism. This support mechanism is provided with three leg portions having a spherical tip from the supported member, one of which is in contact with the three support surfaces constituting the triangular pyramid hole on the pedestal, and the other one on the pedestal. The other one leg is in contact with the flat surface on the pedestal.
Further, in Patent Document 1, a leg portion is supported by two columnar members that can change the distance between the shafts in place of the support surface of the Kelvin clamp, and the height of the leg portion is changed by changing the distance between the axes of the columnar members. A support mechanism is described in which the position and orientation are adjusted by changing the direction position.
JP-A-9-210293 (page 2-5, FIGS. 1, 4 and 11)

However, the conventional optical element support mechanism as described above has the following problems.
Since the Kelvin clamp described in the prior art of Patent Document 1 is a fixed support mechanism, there is a problem that it cannot be used for a support mechanism that requires position adjustment, such as an optical element used in an optical communication device or the like. . Further, since the leg portion is provided on the supported member, there is a problem that the leg portion is not suitable for supporting an optical element in which the leg portion is difficult to be provided due to the structure or manufacturing.
Further, in another technique described in Patent Document 1, although the position of the leg can be adjusted by changing the support height of the leg by a combination of two cylindrical members instead of the support surface of the leg, Since the height direction is variable, the adjustment is limited to translational movement in the height direction and rotational movement about the biaxial direction. Therefore, although it can cope with adjustment of a plane mirror or an axially symmetric optical element, there is a problem that the degree of freedom of adjustment is insufficient in the case of an optical element having a free-form surface or an optical element constituting an eccentric optical system. Further, the point that the leg portion must be provided on the supported member is the same as that of the Kelvin clamp, and there is a problem that the leg portion is not suitable for supporting the optical element in which the leg portion is difficult to be provided due to the structure or manufacture.

  The present invention has been made in view of the above problems, and provides a simple optical element support mechanism that supports an optical element with high accuracy and can adjust the position and orientation of the optical element in an arbitrary direction. For the purpose.

In order to solve the above-described problems, an optical element support mechanism according to the present invention includes an optical element having a support surface in which three different directions that are not on the same plane are normal directions, and the optical element is the support surface. 6 support members for abutting and supporting any of the above, an elastic member for urging the optical element against the support member, and a holding member for holding the elastic member and the support member, The support member is movably held in a predetermined direction with respect to the holding member, and the support surface is referred to as a first support surface, a second support surface, and a third support surface in each of three different directions. Three of the support members are in contact with the first support surface, two of the support members are in contact with the second support surface, and one of the support members is in contact with the third support surface. The support member moves. Predetermined direction, a structure that is a direction crossing the support surface abutting respectively.
According to such a configuration, the optical element is held by the holding member in a state in which the optical element is urged and supported by the elastic member against the six supporting members.
And the attitude | position of a 1st support surface is determined because three support members contact | abut on the 1st support surface of an optical element. In addition, two support members are brought into contact with the second support surface that is in a positional relationship intersecting the first support surface, and one in-plane direction of the first support surface and the in-plane rotation angle are determined. In addition, one support member is brought into contact with the third support surface that is in a positional relationship intersecting the first and second support surfaces, and the position of the second support surface in the in-plane direction is determined. Therefore, the six degrees of freedom of the optical element are constrained, and the position and posture are fixed in a state where the optical element can be regarded as a rigid body. Therefore, the optical element is accurately positioned.
Since the six support members are supported by the holding member so as to be movable in a direction intersecting with the support surfaces that come into contact with each other, the position and posture of the optical element with respect to the holding member can be adjusted by appropriately moving these support members. Variable over all 6 degrees of freedom.
In addition, since the position and orientation can be adjusted by moving the six support members, a simple mechanism can be achieved.
In addition, it is good also considering the support surface which makes three different directions a normal direction, respectively. The support surface of each normal direction is good also as plural according to the number of the support members contact | abutted to it.

In the optical element support mechanism of the present invention, by combining the movement of the support member, the optical element can be translated along the three axial directions orthogonal to each other and can be rotated around the three axial directions. It is preferable that the structure is supported as described above.
In this case, since it is supported so that translational movement along each of the three axial directions orthogonal to each other and rotational movement around the three axial directions are possible, the position in the XYZ rectangular coordinate system and the X, Y in the XYZ rectangular coordinate system Since the position and orientation of the optical element can be varied depending on the rotation angle around each Z axis, adjustment work is facilitated.

The optical element support mechanism of the present invention includes a position / orientation detection sensor that detects a position and an angle / orientation of the optical element, and a moving unit that moves the support member in each of the predetermined directions. It is preferable that the moving unit is controlled based on the detection output of the detection sensor so that the position and angle orientation of the optical element can be automatically adjusted to a target value.
In this case, since the moving means can be controlled based on the detection output of the position / orientation detection sensor to automatically adjust the position and angle / orientation of the optical element to the target value, the position / orientation of the optical element can be easily adjusted with high accuracy.

In the optical element support mechanism according to the present invention, the elastic member that urges the optical element in a certain direction may be configured to vary the urging force along a direction that intersects the certain direction. preferable.
In this case, when the elastic member urges the optical element in a certain direction, the urging force can be varied along the direction intersecting the certain direction, so that the inclination angle is changed in the direction where the optical element intersects the certain direction. Even when a rotational movement is to be made, the urging force can be varied in accordance with the movement, so that such a rotational movement can be allowed while maintaining the urging in a certain direction. Therefore, even when performing adjustment in which translational movement and rotational movement are mixed, reliable urging can be performed, so that highly accurate position and posture adjustment can be performed.

In the optical element support mechanism according to the present invention, in the configuration in which the urging force can be varied along the direction in which the elastic member intersects with a certain direction, the direction in which the elastic member intersects with the certain direction has a width. It is preferable to use a leaf spring provided with a plurality of slits in the width direction.
In this case, since the elastic member is composed of a leaf spring provided with a plurality of slits, the elastic member can be made inexpensive and simple.

In the optical element support mechanism of the present invention, it is preferable that the optical element is a free-form curved mirror.
In this case, the three-dimensional position and posture of the free-form curved mirror can be accurately adjusted and supported by a simple and compact mechanism.

  According to the support mechanism for an optical element of the present invention, the three support surfaces provided on the optical element are supported by a total of six support members, so that the optical element is accurately positioned without distortion, and each of these support members is 1 By moving in the axial direction, the position and orientation of the optical element relative to the holding member can be varied over all six degrees of freedom, so that a simple mechanism can support the optical element with high accuracy and adjust its position and orientation in any direction. There is an effect.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In all the drawings, even if the embodiments are different, the same or corresponding members are denoted by the same reference numerals, and common description is omitted.
[First Embodiment]
The support mechanism for the optical element according to the first embodiment of the present invention will be described.
FIG. 1A is an explanatory perspective view for explaining a schematic configuration of a support mechanism for an optical element according to the first embodiment of the present invention. FIG. 1 (b) is a perspective explanatory view as seen from the opposite direction to FIG. 1 (a). FIG. 2 is an exploded perspective view of the support mechanism for the optical element according to the first embodiment of the present invention. 3A and 3B are a front explanatory view and a side explanatory view for explaining the optical element according to the first embodiment of the present invention. 4 (a) and 4 (b) are perspective explanatory views for explaining the elastic member according to the first embodiment of the present invention. FIG. 5A is a side view for explaining the support member according to the first embodiment of the present invention. FIGS. 5B and 5C are a side view and a perspective view for explaining a modified example of the support member.

  In the following, for convenience, an XYZ rectangular coordinate system common to the drawings may be used to refer to the direction. This coordinate system is a right-handed system, and the rotation direction in which the right screw advances in the positive directions of the X, Y, and Z axes is positive, and the rotation angles around the respective axes are referred to as α, β, and θ.

The adjustment support mechanism 50 (optical element support mechanism) of the present embodiment adjusts the position and orientation of, for example, a reflection mirror, a half mirror, a lens, a prism, a DOE (Diffractive Optical Element), a hologram element, and the like. This is a mechanism for adjusting a required optical element to a predetermined position and posture and maintaining the state. In the following description, the free-form curved mirror 1 is used as an example of the optical element.
As shown in FIGS. 1A and 1B, the schematic structure of the adjustment support mechanism 50 includes a mirror holder 2 (holding member), a free-form surface mirror 1 (optical element), and presser springs 3, 4, 5, 6 ( Elastic member), adjusting screws 7a, 7b, 7c (supporting member), adjusting screws 8a, 8b (supporting member), and adjusting screw 9 (supporting member).

As shown in FIGS. 1 and 2, the mirror holder 2 is formed with a wall 2b extending parallel to the XY plane on the upper portion (Y-axis positive direction) of the fixing portion 2A having a fixing surface 2n parallel to the ZX plane. It is a substantially L-shaped member as viewed in the X-axis direction.
Mounting holes 2j and 2j for mounting the adjustment support mechanism 50 to the apparatus are provided in the fixed portion 2A so as to penetrate in the thickness direction.
Side walls 2c, 2d, 2e, and 2f are formed on the outer periphery of the wall 2b so as to be arranged in a substantially rectangular shape when viewed from the positive direction of the Z axis and extend in the positive direction of the Z axis. That is, the wall 2b, the side walls 2c, 2d, 2e, and 2f form a box-shaped space that opens in the positive direction of the Z axis. This space is sized so that a free-form surface mirror 1 to be described later can be accommodated with an appropriate gap.

At the approximate center of the wall 2b, there is formed an opening 2k through which the back surface 1b can be exposed when the free-form mirror 1 is attached, and the adjusting screws 7a, 7b, 7c are moved in the Z-axis direction (predetermined direction) in the vicinity thereof. Three screw holes 2g for holding in a possible manner are formed so as to penetrate in the thickness direction (see FIG. 2).
For example, one screw hole 2g is arranged on the left side (X-axis direction) on the upper side of the opening 2k (Y-axis positive direction) and the other two on the lower side of the opening 2k (Y-axis negative direction). The connecting virtual line is formed in the Z-axis direction substantially orthogonal to the wall 2b at a position forming a substantially equilateral triangle.
In this embodiment, the opening 2k is provided so that the position and orientation of the free-form curved mirror 1 can be detected by, for example, irradiating the back surface 1b with a detection beam. In this case, the detection beam is formed in a rectangular shape that can enter and exit. On the other hand, for example, when a light-transmitting optical element such as a lens is used as the optical element, it can also be used as an opening for allowing the transmitted light of the optical element to pass therethrough.

The side walls 2c and 2e are disposed on the negative side and the positive side in the X-axis direction, respectively, and extend substantially parallel to each other along the Y-axis direction.
The side walls 2c and 2e are provided with fixing screw holes 2m and 2m, respectively, so that the presser springs 3 and 5 can be fixed by screws 12 and 12, respectively.
The side wall 2e is provided with screw holes 2h and 2h penetrating in the thickness direction for holding the adjusting screws 8a and 8b so as to be movable in the X-axis direction (predetermined direction).

The side walls 2d and 2f are disposed on the negative side and the positive side in the Y-axis direction, respectively, and extend substantially parallel to each other along the Y-axis direction.
The side walls 2c and 2e are provided with fixing screw holes 2m and 2m, respectively, so that the presser springs 3 and 5 can be fixed by screws 12 and 12, respectively.
The side wall 2f is provided with a screw hole 2i penetrating in the thickness direction for holding the adjustment screw 9 so as to be movable in the Y-axis direction (predetermined direction).

  The mirror holder 2 may be made of any material as long as it can hold the free-form surface mirror 1 with high accuracy. For example, a metal, a synthetic resin, or the like can be used. In the case of a metal, for example, it can be produced by cutting super duralumin.

As shown in FIGS. 3A and 3B, the free-form surface mirror 1 has a free-form surface at the center on the front side of the flange portion 1B having a back surface 1b (first support surface) having a substantially rectangular plane. This is a reflective optical element in which a mirror part 1A having a reflective surface 1a (optical surface) having a shape is protruded.
Side surfaces 1c and 1d, a side surface 1e (second support surface), and a side surface 1f (which are orthogonal to the rear surface 1b and form a rectangular side in a plan view (viewed in the Z-axis direction) are provided at the side ends of the flange portion 1B. A third support surface is formed. On the front surface side of the flange portion 1B, flange upper surfaces 1i, 1j parallel to the back surface 1b are formed adjacent to the side surfaces 1e, 1f, and a rectangular ridge line is chamfered adjacent to the side surfaces 1c, 1d. Chamfered portions 1g and 1h, which are surfaces, are provided, respectively.

  The flange upper surfaces 1 i and 1 j are receiving surfaces for biasing force in the negative Z-axis direction by the presser springs 5 and 6. The chamfered portion 1g (1h) is a receiving surface for urging force in the Z-axis negative direction and the X-axis positive direction (Y-axis positive direction) by the presser spring 3 (4) (see FIG. 3B).

  The free-form curved mirror 1 has a back surface 1b, side surfaces 1c, 1d, 1e, and 1f as a wall 2b and a side wall 2c, respectively, with respect to a box-shaped space composed of the wall 2b and side walls 2c, 2d, 2e, and 2f of the mirror holder 2. 2d, 2e, and 2f.

The gap between the free-form mirror 1 and the mirror holder 2 is set according to the movable range required for position and orientation adjustment. For example, when the length of one side of the flange portion 1B is 50 mm, and a movable range of, for example, 1 mm for translational movement in the X-axis direction and 2 ° for θ rotational movement is provided, the gap between the side surface 1e and the side wall 2e is 1 mm + 50 mm XSin2 ° = 2. Set to a gap of 2.75 mm or more.
The thickness of the flange portion 1B only needs to have a rigidity that allows the deformation of the reflecting surface 1a to be within an allowable range when being held on the mirror holder 2, but in this embodiment, the Z-axis of the side wall 2c and the like is held at the time of holding. The thickness is set so as not to protrude from the end face on the positive direction side.

As the reflecting surface 1a, a free-form surface having a three-dimensional curvature, such as a rotationally asymmetric free-form surface or a free-form surface having no symmetry, can be adopted as necessary. In order to arrange such a free-form surface at a design position of the optical system, it is necessary to match the position of each point on the free-form surface to a position uniquely determined with respect to the reference coordinates. For this reason, it is necessary to adjust the position and orientation with six degrees of freedom by combining translation in three directions and rotational movement about three axes.
If the degree of freedom of adjustment is less than 6, the position becomes indefinite. If it is more than 6, the movement is restricted during adjustment and the free-form curved mirror 1 is deformed.

The free-form surface mirror 1 may be made of any material as long as the reflective surface 1a can be processed and the necessary dimensional stability and rigidity can be obtained. For example, glass, synthetic resin, metal, etc. can be employed.
For example, when the free-form surface mirror 1 used for an optical communication device or the like is manufactured with a synthetic resin, a molded product such as ZEONEX 480R (trade name) manufactured by Nippon Zeon Co., Ltd. is cut as an example, and then light having a wavelength of 800 nm to 1600 nm is obtained. On the other hand, it is possible to suitably employ a configuration having a reflective coating such as a gold coat having a high reflectance.

The presser springs 3, 4, 5, and 6 press the free curved mirror 1 stored in the box-shaped space of the mirror holder 2 at the chamfered portions 1g and 1h and the flange upper surfaces 1i and 1f, respectively. It is an elastic member for energizing towards.
In this embodiment, as shown in FIG. 2, the presser springs 5 and 6 have substantially the same shape, and the presser springs 3 and 4 have the same shape.

As shown in FIG. 4A, the presser spring 6 includes a flat plate-like fixing portion 6B having mounting holes 6b and 6b for fixing with screws 12 and 12, and a width of the fixing portion 6B from the fixing portion 6B. At both ends in the direction (X-axis direction), spring portions 6A and 6A each having a width W extended in a substantially perpendicular direction to the fixed portion 6B in a side view (viewed in the X-axis direction). A notch for providing a mounting space for an adjusting screw 9 to be described later is provided at an intermediate portion in the width direction of the fixing portion 6B.
In the case of the present embodiment, the spring portion 6A has a waveform having a convex curve in the negative Z-axis direction when viewed from the side, and is pressed against the flange upper surface 1j by bending in the Z-axis direction, thereby It can be biased in the direction. And it consists of a plurality of (for example, four) leaf springs divided into a comb shape by slits 6a... Provided at appropriate pitches (for example, 3 mm intervals) along the width direction in plan view (viewed in the Z-axis direction). For this reason, the spring portion 6A is configured such that a plurality of leaf springs in the width direction can be independently bent according to an external force.

  As shown in FIG. 2, the presser spring 5 includes a spring portion 5A similar to the spring portion 6A, and instead of the fixed portion 6B, a width direction (Y-axis direction in FIG. 2) instead of a notch in the intermediate portion. The fixing portion 5B is provided with notches for passing adjustment screws 8a and 8b, which will be described later, at both ends.

As shown in FIG. 4 (b), the presser spring 3 (4) has a flat plate-like fixing portion 4B (3B) having mounting holes 4b (3b) and 4b (3b) for fixing using screws 12 and 12. ) And both ends of the fixing portion 4B (3B) to the fixing portion 4B (3B) in the width direction (X-axis direction), respectively, with respect to the fixing portion 4B (3B) in the side view (X-axis direction view) It consists of spring portions 4A (3A) and 4A (3B) of width W bent so as to be convex in the negative direction.
In the present embodiment, the spring portion 4A (3A) is a free-form surface mirror according to the inclination of the chamfered portion 1h (1g) by the convex portion being pressed by the chamfered portion 1h (1g) and bending in the Z-axis direction. 1 can be urged in the Z-axis direction negative direction and the Y-axis positive direction (X-axis positive direction).
Further, the spring portion 4A (3A) has a plurality of (for example, four) divided into a comb shape by slits 4a (3a)... Provided at appropriate pitches (for example, 3 mm intervals) along the width direction when viewed in the Z-axis direction. It consists of a leaf spring. For this reason, the spring portion 4A (3A) is configured such that a plurality of leaf springs in the width direction can be independently bent in accordance with an external force.

  The presser springs 3, 4, 5, 6 can be manufactured by pressing a metal plate having excellent spring properties such as a stainless steel plate and a phosphor bronze plate, for example.

In the case of this embodiment, the adjusting screws 7a, 7b, 7c, 8a, 8b, 9 have the same shape as shown in FIG. Therefore, a detailed shape will be described with an example of the adjusting screw 7a.
As shown in FIG. 5 (a), the adjustment screw 7a has a contact portion 70a that contacts and supports the back surface 1b of the free-form surface mirror 1 at the longitudinal tip, and a male screw that engages with the screw hole 2g in the middle portion. The screw portion 70b is also an axial screw having a screw head portion 70c for rotating the adjusting screw 7a around the axial direction at the rear end.

  It is preferable that the contact portion 70a has a substantially point contact shape so that the contact portion 70a stably contacts the back surface 1b without play and the sliding resistance is reduced and the direction of the sliding resistance is not generated. In the present embodiment, the contact portion 70a is a hemispherical surface. However, the curved surface is not limited to a hemispherical surface as long as the curved surface has a curvature smaller than the curvature of the contact surface of the back surface 1b.

  In this embodiment, the screw head portion 70c has a hexagonal hole shape and can be rotated using a tool / jig such as a hex key. However, as long as the adjusting screw 7a can be rotated around the axial direction, it may have any shape. For example, a hexagonal bolt head shape, a shape with a cross hole, or the like can be suitably employed.

Further, in order to enable manual rotation without using a tool or jig, an adjustment screw 17 shown in FIG. 5C or the like may be employed as a support member.
The adjustment screw 17 includes a disk-shaped operation gripping portion 17c having a larger diameter than the male screw portion 70b instead of the screw head portion 70c of the adjustment screw 7a. It is preferable to form a knurling or the like for preventing slipping on the outer periphery of the operation gripping portion 17c so as to facilitate manual rotation.
For example, the diameter of the operation gripping portion 17c is 20 mm with respect to the diameter of the male screw portion 70b being 2 mm and the screw pitch being 0.4 mm. In this case, when the operation gripping portion 17c is rotated by 2 mm in the circumferential direction, the rotation angle becomes 2 mm / (20 mm / 2) = 0.2 rad, so the amount by which the contact portion 70a is screwed is 0.4 mm × 0. .2 / (2π) = 0.127 mm, and fine adjustment is easy even with manual rotation. For example, if the diameter of the operation gripping portion 17c is doubled, the screwing amount is about 0.006 mm, which is half, so that the degree of coarse / fine adjustment can be appropriately set.

  In this case, as shown in FIG. 5B, the coil spring 10 externally inserted into the screw portion 17b is disposed between the holder portion 2B of the mirror holder 2 and the operation gripping portion 17c, and the holder portion 2B is It is preferable that the adjustment screw 17 can be biased toward the operation gripping portion 17c (in the direction of the arrow in the drawing). In this way, since the screw portion 17b is urged in the axial direction with respect to the screw hole 2g, the axial play of the screw fitting is eliminated, and the position of the contact portion 70a with respect to the mirror holder 2 is more stable. There is an advantage that high-precision adjustment can be performed.

Next, the operation of the adjustment support mechanism 50 will be described.
6A and 6B are schematic operation explanatory views in front view and plan view for explaining the operation of the adjustment support mechanism 50. FIG.
As shown in FIG. 1A in the assembled state, the adjustment support mechanism 50 has a flange portion of the free-form mirror 1 in a box-like space formed by the walls 2b, 2c, 2d, 2e, and 2f of the mirror holder 2. 1B is disposed, the flange upper surfaces 1j and 1i are urged in the negative direction of the Z-axis by the presser springs 6 and 5, and the chamfered portions 1g and 1h (see FIG. 3A) are respectively pressed by the presser springs 3 and 4 by the Z-axis. It is biased in the negative direction, the X-axis positive direction, and the Y-axis positive direction.
For this reason, as shown in FIGS. 6A and 6B, the back surface 1b of the free-form curved mirror 1 is pressed against the adjusting screws 7a, 7b, and 7c so as to come into contact with the contact portion 70a, respectively. Point supported. Further, when the side surface 1e is pressed against the adjusting screws 8a and 8b, the side surface 1e comes into contact with the contact portion 70a and is supported at two points by them. Further, when the side surface 1f is pressed against the adjusting screw 9, it comes into contact with the contact portion 70a and is supported at one point.
Therefore, the free-form curved mirror 1 is supported at three points in the Z-axis direction, supported at two points in the X-axis direction, and supported at one point in the Y-axis direction. Are held by the mirror holder 2 in a state where they are all restrained.

For this reason, the position and posture of the free-form surface mirror 1 are uniquely determined by moving each adjustment screw independently. When one adjustment screw (for example, the adjustment screw 8a) is moved, the support surface (for example, the side surface 1e) with which the adjustment screw abuts moves in a predetermined direction (for example, the X-axis negative direction). At that time, since the free-form mirror 1 is urged against the respective adjustment screws by the elastic member, the contact portions 70a of the respective adjustment screws and the respective support surfaces are held so as to be slidable and movable. Has been.
Each support surface moves in a direction intersecting with the moving direction of each adjusting screw while making point contact with other adjusting screws (for example, adjusting screws 7a, 7b, 7c, 8b, 9). For example, as shown in FIG. 6A, the free-form surface mirror 1 can rotate by θ = θ ₀ within a plane determined by the adjusting screws 7a, 7b, 7c.

That is, the free-form mirror 1 can be translated in the Z-axis direction by moving the adjusting screws 7a, 7b, and 7c in the same direction by the same distance, and the adjusting screws 8a and 8b can be moved in the same direction by the same distance. By doing so, translational movement in the X-axis direction becomes possible, and translational movement in the Y-axis direction becomes possible by moving the adjusting screw 9.
In addition, as shown in FIG. 6B, the free-form surface mirror 1 fixes the position of the adjustment screw 7a and moves the adjustment screws 7b and 7c by the same distance in opposite directions, for example, β = β ₀ Thus, rotational movement around the Y axis is possible. Further, the adjustment screws 8a and 8b are moved in the opposite directions by the same distance, thereby enabling rotational movement around the Z axis. Further, the adjustment screws 7b and 7c are moved in the same direction by the same distance, and the adjustment screw 7a is moved in the opposite direction by the same distance, thereby enabling rotational movement around the X axis.
Then, by appropriately combining these, translational movement and rotational movement in any direction can be realized simultaneously within each movable range.

Since the flange portion 1B is provided on the outer peripheral side of the reflecting surface 1a, which is an optical surface, so as to have a sufficient level of rigidity with the reflecting surface 1a, the urging force from the elastic member is applied to the flange upper surfaces 1i, 1j, A distributed load is applied to each of the chamfered portions 1g and 1h. Accordingly, since a relatively large urging force is not applied as a point load, the deformation of the reflecting surface 1a due to the urging force can be prevented. Further, even if the position of the free-form curved mirror 1 moves, the point of action of the urging force does not change as a whole, so that it is possible to urge with good balance.
In the present embodiment, since the presser springs are provided with the slits 3a, 4a, 5a, 6a, the urging force can be varied in a direction intersecting with the direction of the urging force. Therefore, there is an advantage that the free-form surface mirror 1 can be easily rotated and moved reliably.

Note that the biasing force may be given as close to a concentrated load as long as the deformation of the free-form curved mirror 1 is within an allowable range. In that case, in order to suppress deformation of the flange portion 1B, an urging force can be applied to a position substantially opposed to the contact portion 70a with the flange portion 1B sandwiched between the adjustment screws 7a, 7b, and 7c. It is preferable to arrange the positions of the elastic member and the support member.
For example, a coil spring, a wire spring, or the like can be used as the elastic member that applies an urging force close to the concentrated load. In addition, a member obtained by appropriately shaping a synthetic rubber, an elastomer, or the like can be used.

As described above, according to the present embodiment, the position and orientation of the optical element can be adjusted in an arbitrary direction, which is suitable as a support mechanism for an optical element having a free-form surface, for example.
During the adjustment and support, the optical element is not restrained from moving, so that the optical surface of the optical element is not distorted and can be supported with high accuracy.
Further, such a support mechanism has an advantage that it can be configured simply and inexpensively using six adjustment screws as the support member and three presser springs as the elastic member.

[Second Embodiment]
An optical element support mechanism according to a second embodiment of the present invention will be described.
FIG. 7 is a perspective explanatory view for explaining a schematic configuration of a support mechanism for an optical element according to the second embodiment of the present invention. FIG. 8 is a cross-sectional explanatory view in the axial direction for explaining the schematic configuration of the moving means of the support mechanism of the optical element according to the second embodiment of the present invention. FIG. 9 is an AA cross-sectional view of FIG. 7 for explaining the schematic configuration of the position and orientation detection sensor used in the optical element support mechanism according to the second embodiment of the present invention, and an operation for explaining the detection operation. It is explanatory drawing. FIG. 10 is a functional block diagram for explaining a schematic configuration of the position and orientation adjustment control means of the optical element support mechanism according to the second embodiment of the present invention.

The adjustment support mechanism 51 (optical element support mechanism) of the present embodiment includes a position / orientation detection sensor that detects a position and an angle / orientation of the optical element, and a support member moving unit that movably supports the optical element. The position and angle orientation of the optical element can be automatically adjusted.
As shown in FIG. 7, the schematic configuration of the adjustment support mechanism 51 includes a mirror holder 20 instead of the mirror holder 2 of the adjustment support mechanism 50 of the first embodiment, and includes adjustment screws 7a, 7b, 7c, 8a, In place of 8b and 9, actuators 21a, 21b, 21c, 22a, 22b and 23 (moving means) having adjustment pins 28 (supporting members) are provided, and in addition to them, position and orientation detection sensors 24, 25 and 26, and 7 is provided with automatic adjustment control means 100 (see FIG. 10) not shown in FIG.
Hereinafter, a description will be given focusing on differences from the first embodiment.

The mirror holder 20 is formed with a wall 20b extending in parallel to the XY plane on the upper portion (Y-axis positive direction) of the fixed portion 20A having the fixed surface 2n parallel to the ZX plane, and is attached to the sensor facing the wall 20b. This is a member provided with the portion 20E.
An attachment hole 2j for attaching the adjustment support mechanism 51 to the apparatus is provided in the fixed portion 20A so as to penetrate in the thickness direction.
Side walls 20c, 20d, 20e, and 20f that are substantially the same as the side walls 2c, 2d, 2e, and 2f of the mirror holder 2 are formed on the outer periphery of the wall 20b. That is, the wall 20b and the side walls 20c, 20d, 20e, and 20f form a box-shaped space that opens in the positive direction of the Z axis. This space is sized so that the free-form curved mirror 1 can be accommodated with a gap similar to that of the first embodiment.
Further, the side walls 20c, 20d, 20e, and 20f are not shown because they are on the back surface side, but the presser springs 3, 4, 5, and 6 are attached by screws 12 as in the case of the fixing portion 2A. Yes.

Unlike the fixing portion 2A, in the fixing portion 20A, instead of the screw holes 2g, 2i, and 2h, through holes 29 through which the adjustment pins 28 can penetrate are provided.
In addition, openings 20q and 20p are provided at substantially central portions in the longitudinal direction of the side walls 20c and 20f at positions where the side surface 1c and the side surface 1f can be seen, respectively.
Further, in the vicinity of the opening 20q (20p), a sensor mounting portion 20C (20D) that is formed in an inverted L shape in the X-axis view (Z-axis view) from the side wall 20c (20f) is in the Y-axis positive direction (X-axis). It is provided so as to cover the opening 20q (20p) when viewed from the negative direction. The opening 20q (20p) and the sensor mounting portion 20C (20D) that includes the opening 20q are spaced apart from each other by a certain distance in the Y-axis direction (X-axis direction).
The wall 20b is provided with an opening 20k instead of the opening 2k.

In the case of the present embodiment, it is assumed that the free-form surface mirror 1 has a mirror surface formed on at least the back surface 1b and the side surfaces 1c, 1f exposed by the openings 20k, 20q, 20p.
The openings 20k, 20q, and 20p are sized and shaped such that when a light beam having a predetermined diameter is incident from an oblique direction, the spots on the back surface 1b, the side surfaces 1c, and 1f and the reflected light thereof are not shattered. ing.

Actuators 21a, 21b, 21c, 22a, 22b, and 23 are provided on the shafts of the through holes 29, respectively.
The actuators 21a, 21b, and 21c are provided on the wall 2b, the actuators 22a and 22b are provided on the side wall 20e, and the actuator 23 is provided on the side wall 20f.

As shown in FIG. 8, these actuators have a common configuration including an adjustment pin 28 (support member) and a drive unit 27.
The adjustment pin 28 is a shaft-like member having a contact portion 70 a at the tip, and can be advanced and retracted in the axial direction by the drive portion 27.
The drive unit 27 is a mechanism capable of moving the adjustment pin 28 forward and backward in a direction perpendicular to the wall 20b and the side walls 20e and 20f which are the attachment surfaces by a control signal of the automatic adjustment control means 100.
For example, when a constant angle rotation drive mechanism such as a stepping motor is employed as the drive unit 27, a male screw is formed on the shaft portion as the adjustment pin 28, a female screw is formed on the drive unit 27 side, and the adjustment pin 28 is rotationally driven. A mechanism for advancing and retreating can be configured.
Further, for example, when a linear motion mechanism such as a linear motor is employed as the drive unit 27, the adjustment pin 28 may be a pin member joined to the movable part of the linear motor, or the adjustment pin 28 itself may be magnetized, for example. It is good also as a structure which forms the movable part of a linear motor as a stick member etc. which were made.

As shown in FIG. 9A, the position / orientation detection sensors 24, 25, and 26 are provided with side surfaces 1f, 1c, and a back surface 1b of the free-form curved mirror 1 each having a mirror surface formed from a detection beam 32 shaped to a predetermined diameter. And a CCD 30 as a two-dimensional image sensor that images the spot shape of the detection beam 32 reflected by each mirror surface.
In the present embodiment, the detection beam 32 projected from the beam light source 31 is a parallel beam having a circular cross section. For example, a configuration in which a laser beam generated by a semiconductor laser is converted into a parallel beam by a collimator lens can be employed.
The CCD 30 has a position and orientation of the imaging surface 30a at a position separated from each mirror surface by an appropriate predetermined distance when each mirror surface is at the positioning reference position, and the light of the detection beam 32 reflected by each mirror surface. It arrange | positions so that it may become the attitude | position orthogonal to an axis | shaft.

As shown in FIG. 10, the automatic adjustment control unit 100 includes an image processing unit 101, a position detection unit 102, a movement amount calculation unit 103, and a drive control unit 104.
The image processing unit 101 is connected to the CCDs 30 of the position / orientation detection sensors 24, 25, and 26, and performs image processing so that the image signals sent from the CCDs 30 can be subjected to position detection calculation. For example, the image signal picked up by each CCD 30 is binarized and a shaping process such as smoothing of an edge portion is performed.
The position detection unit 102 is for calculating the center position of the spot and the outer shape of the spot from the image signal of the spot image-processed by the image processing unit 101. The center position of the spot is calculated, for example, by calculating the center of gravity of the image signal. The outer shape of the spot is calculated, for example, by extracting outline data by edge extraction processing and performing elliptic curve fitting on the data. For example, the major axis direction, major axis, minor axis, etc. of the ellipse are calculated.

The movement amount calculation unit 103 is for calculating the translational movement amount and the rotation movement amount of the mirror surface from the center position of the spot and the outer shape of the spot calculated by the position detection unit 102.
In the present embodiment, since the detection beam 32 is a parallel beam of circular cross section, if the mirror is in the reference position, the detection beam 32, a circular spot 32A where the center is a position P ₀ on the imaging surface 30a (See FIGS. 9B and 9C).
As shown in terms S ₁ in FIG. 9 (a), if the free-form surface mirror 1 is moved in parallel from the reference position with respect to the position and orientation detecting sensor 25, is on the imaging surface 30a, shown in FIG. 9 (b) as described above, in the same round the spot 32A, the spot 32B the center position is moved to the position P ₁ is formed.
Further, as shown in terms S ₂ in FIG. 9 (a), if the free-form surface mirror 1 is rotated and moved from the reference position with respect to the position and orientation detecting sensor 25, the inclined imaging surface 30a has with respect to the optical axis of the reflected light to, as shown in FIG. 9 (c), the spot shape becomes elliptic spot 32C the center position is moved to P ₂ is formed.

  As described above, the degree of the ellipse of the spot corresponds to the inclination angle of the mirror surface with respect to the reference position, and the movement amount of the center position corresponds to the translational movement amount and inclination angle of the mirror surface. Therefore, if these amounts are detected, the tilt angle and the translational movement amount with respect to the reference position of the mirror surface can be calculated based on the distance of the CCD 30 to the mirror surface and the projection angle of the detection beam 32.

In the above, for the sake of simplicity, the case of translational movement and rotational movement in one axial direction has been described, but the same applies to general translational movement and rotational movement.
That is, the movement amount calculation unit 103 calculates six movement amounts including translational movement amounts in the X-axis, Y-axis, and Z-axis directions, and rotational movement amounts around the X-axis, the Y-axis, and the Z-axis. .
For example, in a complex movement in the three-axis directions, each movement component is accurately calculated by detecting changes in the rotation angle in the principal axis direction of the ellipse of the spot and the absolute value of the minor axis and major axis of the ellipse.
However, in this embodiment, since the position / orientation detection sensors 24, 25, and 26 are provided on three mirror surfaces that are orthogonal to each other, if the amount of movement is small, the influence of other movements is higher. The next minute amount can be ignored. Therefore, it is sufficient to perform the calculation described above for the position and orientation detection sensor.

The drive control unit 104 calculates the drive amounts of the actuators 21a, 21b, 21c, 22a, 22b, and 23 based on the six movement amounts from the reference position of each mirror surface calculated by the movement amount calculation unit 103. This is for generating a control signal corresponding to the control signal.
The target value of the drive amount may be the reference position itself, or may be an adjustment target position and posture different from the reference position. Further, these target values may be varied by inputting to the automatic adjustment control means 100 from an apparatus in which the adjustment support mechanism 51 is installed.

Between the six movement amounts and the drive amount of each actuator, for example, a certain relationship represented by a six-way simultaneous equation is established according to the support position of each actuator. The quantity can be determined simultaneously. Therefore, it is possible to adjust the position and posture of the free-form surface mirror 1 by simultaneously driving the actuators based on the necessary adjustment movement amount.
For these adjustments, if necessary, the position and orientation may be detected by sampling at appropriate intervals, and the position and orientation may be constantly adjusted so that the deviation amount with respect to the target value is equal to or less than the allowable value.

According to the adjustment support mechanism 51 of the present embodiment, the detection beam 32 from the position / orientation detection sensors 24, 25, and 26 is applied to the side surface 1f, the back surface 1b, and the side surface 1c in a state where the free-form curved mirror 1 is incorporated in the mirror holder 20. The reflected light is picked up by each CCD 30, and the image signal is sent to the automatic adjustment control means 100, whereby the amount of deviation from the reference position is detected. Then, the actuators 21a, 21b, 21c, 22a, 22b, and 23 are driven according to the amount of deviation, so that the position and orientation of the free-form curved mirror 1 are automatically adjusted toward the target value.
Therefore, adjustment with six degrees of freedom can be performed easily and quickly.
The adjustment support mechanism 51 can be used as an optical deflector, for example, when the target value can be varied based on an input from a device in which the adjustment support mechanism 51 is installed.

  In the above description, the optical element is described as a reflective optical element when the optical surface is a reflective surface, but as a transmissive optical element, for example, a half mirror, a lens, a prism, a DOE, or a hologram element is used. The holding member can have substantially the same configuration as described above except that an opening for securing a transmitted light path is provided.

Further, in the above description, the example in which the three support surfaces of the optical element that are not parallel to each other are the bottom surface and the side surface of the optical element has been described, but there may be a plurality of support surfaces depending on the number of support members. Good.
FIG. 11A is a perspective explanatory view for explaining a first modification of the optical element.
In the lens 40 of the first modification, a lens portion 40A is formed in a substantially disc-shaped central portion, and a flange portion 40B is provided on the outer peripheral side thereof. A back surface 1b parallel to the XY plane shown in the figure is formed as a first support surface on one side in the thickness direction of the flange portion 40B, and recesses 40a, 40b, and 40c are provided on the sides of the flange portion 40B. In the recesses 40a and 40b, support surfaces 41 and 41 parallel to the illustrated YZ plane are formed as second support surfaces. In the recess 40c, a support surface 42 parallel to the ZX plane shown in the figure is formed as a third support surface.

  With such a configuration, even if the outer shape of the optical element is circular, a support surface can be provided. For example, the present invention is also applied to an optical element that has a circular outer shape in order to have an axially symmetric surface. Can be easily applied. For example, it is suitable when a glass lens having a circular outer shape is used.

FIG. 11B is a perspective explanatory view for explaining a second modification of the optical element.
The lens 43 of the second modified example has a lens portion 40A formed in a substantially disc-shaped central portion, and a flange portion 40B provided on the outer peripheral side thereof. A back surface 1b parallel to the XY plane shown in the figure is formed as a first support surface on one side in the thickness direction of the flange portion 40B, and convex portions 43a and 43b are provided on the sides of the flange portion 40B. A support surface 41 parallel to the YZ plane shown in the figure is formed on the convex portion 43a as a second support surface. In addition, a support surface 42 parallel to the illustrated ZX plane is formed on the convex portion 43b as a third support surface.

  With such a configuration, the support surface is provided with a convex portion where necessary, so that an optical element with good material use efficiency can be obtained. For example, when a synthetic resin molded lens having a circular optical surface is employed, there is an advantage that the material cost can be reduced and the shape can be improved.

Further, in the description of the second embodiment, the example in the case of performing image processing on the shape of the reflected light of the parallel light beam as the position / orientation detection sensor has been described. If it is appropriately changed, the spot shape and the change in position depending on the position and posture of the reflecting surface can be specified.
Further, the position and orientation detection sensor system is an example, and other systems may be employed as long as the position and orientation of the optical element can be detected.
For example, it is possible to employ a method in which a plurality of non-contact distance measuring sensors are arranged on the detection surface and the translation movement and the point movement of the detection surface are detected. As the non-contact distance measuring sensor, for example, an appropriate sensor such as an optical type or an electrostatic type can be adopted.

Further, in the above description, the example is described in which all are manually adjusted or all are automatically adjusted. However, the position / orientation detection sensor and the moving unit are provided in part, for example, to automate the direction in which manual adjustment is difficult. It may be.
Further, the position / orientation detection sensor and the moving means may be provided so as to be detachable, and may be attached at the time of assembly and automatically adjusted, and removed after the adjustment.

  In the above description, the first to third support surfaces are described as being arranged in directions orthogonal to each other. This has the advantage that the adjustment amount is intuitively easy to understand. However, the support surfaces may intersect each other at an angle different from 90 ° if the three different directions that are not on the same plane are the normal directions. Since the movement amount on these normal lines is decomposed into arbitrary rectangular coordinate system components, the movement equivalent to the case where they are arranged in directions orthogonal to each other can be performed by appropriately adjusting the movement amount.

It is the perspective explanatory view for demonstrating schematic structure of the support mechanism of the optical element which concerns on the 1st Embodiment of this invention, and the perspective explanatory view seen from the opposite direction. It is a disassembled perspective view of the support mechanism of the optical element which concerns on the 1st Embodiment of this invention. It is front explanatory drawing and side explanatory drawing for demonstrating the optical element which concerns on the 1st Embodiment of this invention. It is a perspective explanatory view for explaining an elastic member concerning a 1st embodiment of the present invention. It is side surface explanatory drawing for demonstrating the supporting member which concerns on the 1st Embodiment of this invention, and the side surface explanatory drawing and perspective explanatory drawing of the modification. It is typical operation explanatory drawing of the front view and planar view for demonstrating the effect | action of the support mechanism of the optical element which concerns on the 1st Embodiment of this invention. It is an isometric view explanatory drawing for demonstrating schematic structure of the support mechanism of the optical element which concerns on the 2nd Embodiment of this invention. It is an axial section explanatory view for explaining a schematic structure of a moving means of a support mechanism of an optical element concerning a 2nd embodiment of the present invention. FIG. 8 is an AA cross-sectional view of FIG. 7 for explaining a schematic configuration of a position and orientation detection sensor used for an optical element support mechanism according to a second embodiment of the present invention, and an operation explanatory diagram for explaining a detection operation. . It is a functional block diagram for demonstrating schematic structure of the position and orientation adjustment control means of the support mechanism of the optical element which concerns on the 2nd Embodiment of this invention. It is a perspective explanatory view for explaining the 1st and 2nd modification of an optical element.

Explanation of symbols

1, 40, 43 Free-form surface mirror (optical element)
1b Back surface (first support surface)
1e Side surface (second support surface)
1f Side surface (third support surface)
1g, 1h Chamfer 2, 20 Mirror holder (holding member)
2k, 20k, 20p, 20q Openings 3, 4, 5, 6 Presser spring (elastic member)
3a, 4a, 5a, 6a Slits 7a, 7b, 7c, 8a, 8b, 9 Adjustment screw (support member)
10 Coil spring 10
17 Adjustment screw (support member)
17c Operation gripping portions 21a, 21b, 21c, 22a, 22b, 23 Actuators (moving means)
24, 25, 26 Position and orientation detection sensor 28 Adjustment pin (support member)
30 CCD
31 Beam light source 32 Detection beams 32A, 32B, 32C Spots 40, 43 Lens (optical element)
40a, 40b, 40c Concave portion 43a, 43b Convex portion 41 Support surface (second support surface)
42 Support surface (third support surface)
50, 51 Adjustment support mechanism (support mechanism for optical elements)
70a Contact section 100 Automatic adjustment control means 101 Image processing section 102 Position detection section 103 Movement amount calculation section 104 Drive control section

Claims (6)

An optical element having a support surface in which three different directions that are not on the same plane are normal directions;
6 support members for supporting the optical element in contact with any of the support surfaces;
An elastic member for urging the optical element with respect to the support member;
A holding member for holding the elastic member and the support member,
The support member is held movably in a predetermined direction with respect to the holding member,
When the support surface is referred to as a first support surface, a second support surface, or a third support surface in three different directions,
Three of the support members are in contact with the first support surface,
Two of the support members are in contact with the second support surface,
One of the support members is in contact with the third support surface;
A support mechanism for an optical element, wherein a predetermined direction in which the support member moves is a direction that intersects the support surfaces that contact each other.   By combining the movement of the support member, the optical element is supported so as to be capable of translational movement along three mutually orthogonal axes and rotational movement around the three axes. The optical element support mechanism according to claim 1. A position and orientation detection sensor for detecting the position and angular orientation of the optical element;
Moving means for moving the support member in the respective predetermined directions,
3. The apparatus according to claim 1, wherein the moving unit is controlled based on a detection output of the position / orientation detection sensor so that a position and an angle / orientation of the optical element can be automatically adjusted to a target value. 4. Support mechanism for optical elements.   The optical device according to any one of claims 1 to 3, wherein the elastic member that urges the optical element in a certain direction can change the urging force along a direction that intersects the certain direction. Element support mechanism.   5. The optical element support mechanism according to claim 4, wherein the elastic member includes a leaf spring in which a direction intersecting the certain direction is a width direction and a plurality of slits are provided in the width direction.   The optical element support mechanism according to claim 1, wherein the optical element is a free-form surface mirror.

Images