JP4599698B2 - Drive unit - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a drive unit using a shape memory alloy string , and more particularly to a drive unit suitable for a hand shake mechanism of an optical apparatus such as binoculars.
[0002]
[Prior art]
Conventionally, various camera shake prevention mechanisms for preventing camera shake of an optical apparatus have been proposed, but those that drive the correction optical system are classified into a variable vertex prism type and a lens parallel movement type. Many of the latter lens parallel movement types are thrust drive by a peristaltic coil or lever drive by a motor. Both adopt electromagnetic drive and the response is very good. However, electromagnetic driving has a small driving force per volume, which inevitably increases the size of the entire apparatus. Therefore, a small optical device such as binoculars becomes an obstacle.
[0003]
In order to improve this, a wire-shaped shape memory alloy (SMA), that is, a shape memory alloy cord using a shape memory alloy string has been proposed.
[0004]
For example, Japanese Patent Application Laid-Open No. 10-96976 discloses a camera shutter that is driven using a shape memory alloy string that is screwed through a metal fitting. Japanese Patent Laid-Open No. 6-60577 proposes a hard disk device in which the end portion of a shape memory alloy string bent by a support column is caulked with a lead wire by a connection member, and the connection member is attached to an attachment portion made of an insulator. Has been.
[0005]
[Problems to be solved by the invention]
However, practical application is not progressing. The main cause was difficulty in assembling the shape memory alloy string. In other words, in order to obtain an accurate stroke, together with tight control the length of the shape memory alloy strap, without the deviate, moreover it is necessary to hold suitable for mass production, to achieve this assembly There was no way.
[0006]
Therefore, the technical problem to be solved by the present invention is to provide a drive unit using a shape memory alloy string, which can be assembled with high accuracy by a method suitable for mass production.
[0007]
[Means for Solving the Problems]
In order to solve the above technical problem, the present invention provides a support body having first and second support portions, and both ends thereof are held by the first and second support portions. A shape memory alloy string having a dimension longer than the distance between the support portions, and the support includes conductive first and second support plates provided with the first and second support portions, respectively. And an insulative coupling portion that integrally couples the first and second support plates, and the shape memory alloy string presses and drives the driven body when energized. A drive unit is provided.
[0008]
For example, the configuration is as follows.
[0009]
A shape memory alloy string used as a drive source is press-fitted and held together with a ball or a wedge in a hole provided in a metal base plate.
[0010]
In the above configuration, the base plate corresponds to the first member, and the sphere or the wedge corresponds to the second member. By making the base plate made of metal, it is possible to integrally provide a connection terminal for connecting to an external power source in order to increase the current in the shape memory alloy string.
[0011]
According to the above configuration, since the first and second support plates are insulated by the coupling portion, the connection terminals can be provided on the first and second support plates. The support can be easily manufactured by integral molding or adhesion. The drive unit using the shape memory alloy string can be assembled by a method suitable for mass production.
[0012]
According to the above configuration, since the drive part by the shape memory alloy string is unitized, the drive unit can be attached later to the part including the driven body that is supported movably, and the shape memory alloy string is used. As a result, the assembly work of various devices can be made more efficient.
[0013]
Preferably, the first and second support plates are metal base plates, the first and second support portions are holes, and the shape memory alloy string together with a ball or a wedge together with the first and second support plates. 2 is press-fitted and held in the support portion.
[0014]
When the shape memory alloy string is press-fitted and held together with a ball or wedge into a hole provided in a metal base plate, it can be assembled with high accuracy by a method suitable for mass production. It is also easy to reduce the size by reducing the press-fit holding portion.
[0015]
According to the said structure, when a shape memory joint string is press-fitted in the hole of a base plate with a ball | bowl or a wedge, a shape memory alloy string is hold | maintained in a predetermined direction at a predetermined position by a guide. Therefore, assembly becomes easy. In addition, the assembly accuracy can be improved.
[0016]
For example, the shape memory alloy string is located near the shape memory alloy string that extends when the shape memory coupling string is press-fitted into the hole together with the ball or the wedge. A contact surface extending in a direction substantially perpendicular to the extending direction.
[0017]
Moreover, this invention provides the drive unit using the shape memory alloy string of the following structures.
[0018]
A drive unit using a shape memory alloy string includes a support and a shape memory alloy string. The said support body has a 1st and 2nd support part. Both ends of the shape memory alloy string are held by the first and second support portions and have a length longer than the distance between the first and second support portions.
[0019]
According to the above configuration, the intermediate portion of the shape memory alloy string is pressed against the driven object in a direction substantially perpendicular to the direction connecting the first and second support portions, and the shape memory alloy string is stretched in a “<” shape. The support is fixed in the state where Then, due to the dimensional change of the shape memory alloy, the driven object is pressed in the pressing direction (in the plane including the “<” shape memory alloy string, in a direction substantially perpendicular to the direction connecting the first and second support portions). Can be moved.
[0020]
According to the above configuration, since the drive part by the shape memory alloy string is unitized, the drive unit can be attached later to the part including the driven object supported movably, and the shape memory alloy string is used. As a result, the assembly work of various devices can be made more efficient.
[0021]
Preferably, the support body integrally couples the first and second support plates and the conductive first and second support plates provided with the first and second support portions, respectively. And an insulating coupling portion.
[0022]
According to the above configuration, since the first and second support plates are insulated by the coupling portion, the connection terminals can be provided on the first and second support plates. The support can be easily manufactured by integral molding or adhesion.
[0023]
Preferably, the support has a space formed by retreating from the opening into a substantially “U” shape or an arcuate shape. The shape memory alloy string is disposed so as to cross the space.
[0024]
Preferably, a connection terminal connected to an external power source is provided in the vicinity of the attachment portion in order to pass a current through the shape memory alloy string .
[0025]
Preferably, the support body has a substantially “U” shape between the first and second end portions where the first and second support portions are respectively formed, and between the first and second end portions. Alternatively, the curved portion extends in a bow shape and has an attachment portion for attaching the drive unit at the center.
[0026]
In the above configuration, by forming the attachment portion at the center of the curved portion of the support body, the moments acting on the attachment portion of the support body from the first and second support portions cancel each other due to the expansion and contraction of the shape memory alloy string. can do. Moreover, even if the shape memory alloy string is expanded and contracted, the shape memory alloy string can be prevented from being displaced with respect to the driven object, thereby preventing a decrease in the life of the shape memory alloy string.
[0027]
According to the said structure, the volume of a support body can be made as small as possible, and a drive unit can be reduced in size. Further, the periphery of the shape memory alloy string can be protected by being surrounded by a support. Furthermore, it is also possible to arrange the drive unit along the periphery of the driven object.
[0028]
Preferably, the first and second ends of the support are included in the same plane.
[0029]
According to the said structure, manufacture can be made easy, such as processing of a support body and attachment of a shape memory alloy string.
[0030]
The drive using the shape memory alloy string according to claim 6, wherein a connection terminal connected to an external power source is preferably provided in the vicinity of the attachment portion in order to pass an electric current through the shape memory alloy string. unit.
[0031]
According to the above configuration, since the connection terminal is provided in the vicinity of the attachment portion, even if a force is applied to the connection terminal from the wiring connected to the connection terminal, the support is not deformed, and the position of the shape memory alloy string varies. Can be prevented. Therefore, the drive unit can drive the driven object stably and accurately.
[0032]
Preferably, the support has a through hole through which the intermediate portion of the shape memory alloy string pressed against the driven body passes or approaches between the first and second support portions.
[0033]
According to the above configuration, it is easy to check the engagement between the shape memory alloy string and the driven body from the through hole of the support. When the driven body passes through the through hole, the movement of the driven body can be restricted by the through hole.
[0034]
Preferably, the drive unit is configured such that the amount of movement of the driven object due to the change in the overall length of the shape memory alloy string is greater than the change in the overall length of the shape memory alloy string.
[0035]
According to the above configuration, since the amount of movement of the driven object can be increased even if the shape memory alloy string is short, the drive unit can be configured to be small.
[0036]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, binoculars according to an embodiment of the present invention will be described with reference to the drawings.
[0037]
The binoculars are provided with a camera shake prevention mechanism that allows a target to be seen in a stationary state even when there is a camera shake or the like.
[0038]
FIG. 1 is an external view of the binoculars 10. (A) is a top view, (b) is a rear view, (c) is a front view, and (d) is a right side view.
[0039]
The binoculars 10 can be operated to turn on / off a camera shake prevention mechanism by a camera shake prevention button 14 arranged on the upper surface. The distance between the pair of objective lenses 30 is fixed, but the distance between the pair of eyepieces 20 can be adjusted by changing the angle of the left and right eyepieces 22 with respect to the body 11. The binoculars 10 can be adjusted with a focus adjustment knob 12 disposed on the upper surface, and the diopter difference between the left and right can be adjusted by rotating one outer cylinder 21 of the eyepiece 22. It has become. A battery chamber lid 16 is provided on the eyepiece side of the body 11 so that the battery can be loaded from the eyepiece side.
[0040]
FIG. 2 shows a block arrangement inside the binoculars 10.
[0041]
The binoculars 10 have a pair of left and right optical systems including a pair of objective lenses 30, a correction lens 51, a Porro prism 24, and an eyepiece lens 20.
[0042]
The pair of objective lenses 30 are fixed to one objective lens barrel 32 with cross hatching. The objective lens barrel 32 is held by the body 11 so as to be capable of thrust movement in the optical axis direction for focus adjustment.
[0043]
The pair of correction lenses 51 are held by a single camera shake correction unit 50 with hatching so that they can be driven in two axes. In the camera shake correction unit 50, a base described later is fixed to the body 11.
[0044]
The pair of Porro prisms 24 and the eyepiece 20 are fixed to the left and right prism holders 28a and 28b, respectively. The prism holders 28a and 28b are held by the body 11 so as to be capable of thrust movement in the optical axis direction, and are held so as to be rotatable about the optical axes 30a and 30b of the objective lens 30 with respect to the body 11 and a battery chamber 18 to be described later. Is done.
[0045]
The battery chamber 18 penetrates the camera shake correction unit 50 and is fixed to the body 11. Two cylindrical batteries 2 for supplying power to the control circuit are loaded in the battery chamber 18 in parallel with the optical axes 30a and 30b. The arrangement of the batteries 2 is perpendicular to the line connecting the left and right optical axes 30a and 30b. The control circuit is disposed along the upper surface or the lower surface of the binoculars 10 across the body 11, the prism holders 28 a and 28 b, and the battery chamber 18.
[0046]
The binoculars 10 can adjust the focus and the eyelids in the same way as general binoculars.
[0047]
That is, when the focus adjustment operation unit 12 on the upper surface of the binoculars 10 is operated, the pair of objective lens barrels 32 moves in the optical axis direction, and the focus moves. When the parallax adjustment operation unit 21 of the eyepiece is operated, the diopter of one eyepiece 20 can be adjusted, and thereby the left and right diopter difference can be adjusted. When the left and right eyepieces 20 are moved left and right so as to adjust the distance between them, the prism holders 28a and 28b holding the eyepiece 20 and the prism 24 rotate about the objective lens optical axes 30a and 30b with respect to the body 11. To do. As a result, the objective lens optical axes 30a and 30b and the eyepiece optical axes 20a and 20b are displaced in position by the prism 24, and the eye width can be changed.
[0048]
Next, the configuration of the camera shake correction unit 50 will be described with reference to FIGS.
[0049]
The camera shake correction unit 50 is a unit that supports a pair of right and left correction lenses 51 so as to be swingable by two orthogonal parallel link mechanisms, and includes a lock mechanism that locks the parallel link mechanism.
[0050]
The parallel link mechanism is a planar four-joint mechanism in which four links are connected in a substantially parallelogram shape by four pairs, and other links for a link fixed to a stationary system (referred to herein as a “fixed link”). Of the links (herein referred to as “moving links”), the moving links that face the fixed links move approximately parallel to the extending direction of the fixed links in one plane.
[0051]
FIG. 14 is a conceptual diagram of a parallel link. The correction lens 8 that is a driven member is fixed to the moving link 6 b that faces the fixed link 6 d of the first parallel link mechanism 6. In the first parallel link mechanism 6, four links 6a, 6b, 6c, 6d are coupled in a parallelogram by four pairs. When the movable links 6a and 6c adjacent to the fixed link 6d are rotated as indicated by arrows 6m and 6n through the pair 6s and 6t, the correction lens 8 is approximately in the first direction x parallel to the fixed link 6d. Translate to.
[0052]
The fixed link 6d of the first parallel link 6 is fixed to the moving link 4b facing the fixed link of the second parallel link 4 (which virtually exists between the pair 4s and 4t). When the movable links 4a and 4c adjacent to the fixed link are rotated as indicated by arrows 4m and 4n through the pair 4s and 4t, the correction lens 8 and the first parallel link 4 are roughly the second parallel links. 4 moves in a second direction y parallel to the fixed link. Accordingly, the correction lens 8 is supported so as to be movable in first and second directions x and y that are substantially orthogonal to each other.
[0053]
FIG. 15 is a conceptual diagram of the parallel link mechanism. The parallel link mechanism is composed of one thin leaf spring material, and the link portions 5a, 5b, 5s, and 5t are connected via the deformable portion 5x. The deformable portion 5x is a portion that is less rigid than the link portions 5a, 5b, 5s, and 5t and is easily elastically deformed. For example, the deformable portion 5x is configured only by a surface perpendicular to the paper surface, and the link portions 5a, 5b, 5s, and 5t have an L-shaped cross section from a surface parallel to the paper surface and a surface bent perpendicular to the paper surface. To be rigid.
[0054]
As shown in FIG. 15B, the parallel link mechanism bends at the deforming portion 5x, and the moving link 5s facing the fixed link 5t moves substantially parallel to the extending direction of the fixed link 5t.
[0055]
9A is an external view of the camera shake correction unit 50 viewed from the eyepiece lens side, and FIG. 9B is a partial cross-sectional side view. FIG. 10A is an enlarged perspective view of the main part of the link plate, FIG. 10B is a cross-sectional view through the center of the correction lens, and FIG. 10C is a cross-sectional view of the lock mechanism. FIG. 11 is an external view of the camera shake correction unit 50 as viewed from the objective lens side. FIG. 12 is an external view of the camera shake correction unit 50 excluding the base as viewed from the objective lens side.
[0056]
The camera shake correction unit 50 includes a correction lens holding frame 52 that holds the left and right correction lenses 51, a vertical link plate 54 that is a parallel link mechanism that supports the correction lens holding frame 52 so as to be swingable only in the vertical direction, A holding table 56 for holding the vertical link plate 54; a horizontal link plate 58 that is a parallel link mechanism that supports the holding table 56 so as to be swingable only in the left-right direction; a base 60 for holding the horizontal link plate 58; It includes a correction lens holding frame 52 and a pressing spring 53 that is hung on the base 60.
[0057]
As shown by a solid line in FIG. 9A, the correction lens holding frame 52 has an integral shape in which ball frame portions 52a and 52b for holding the left and right correction lenses 51 are connected by two upper and lower beams 52s and 52t. A hole 52c into which the battery chamber 18 is inserted is formed at the center. Four holes 52x for locking the pressing spring 53 are formed in the hole 52c. As shown in FIGS. 10C and 12, the reference protrusion 52z of the correction lens holding frame 52 is a reference of the base 60. It can be pressed against the surface 60s. Further, the ball frame portions 52a and 52b have a lock mechanism taper at the inner corner triangular portion formed between the upper and lower beams 52s and 52t and the correction lens 51, as shown in FIG. A hole 52y is provided. A projection 52k is provided on the upper and lower beams 52s and 52t so as to pass through the center of gravity, and a V-groove 52v is formed at the center thereof to receive a shape memory alloy string of a drive unit described later.
[0058]
As shown in FIG. 10B, the vertical link plate 54 is supported on the same surface of the correction lens holding frame 52 and the holding table 56 on the eyepiece side. The vertical link plate 54 is made of a thin leaf spring material and constitutes a parallel link mechanism that swings up and down with one component. That is, as shown in FIG. 9A, the vertical link plate 54 has two link arms 54s and 54t extending in the left and right directions, and both ends of the two link arms 54s and 54t are fixed on the left and right, respectively. It is connected to the parts 54a and 54b. One fixing portion 54 a of the vertical link plate 54 is fixed to the holding base 56 on the stationary system side, and the other fixing portion 54 b is fixed to the correction lens holding frame 52. As shown in FIG. 10A, the vertical link plate 54 is bent toward the objective lens side substantially perpendicularly along the link arms 54s and 54t, and the fixed portions 54a and 54b and the link arm portions 54s and 54t are L-shaped. It has a mold section. As shown in FIGS. 9 and 10A, a deformed portion 54x having a narrow width and formed only in a vertical plane is formed at the boundary between the fixing portions 54a and 54b and the link arm portions 54s and 54t. The deformable portion 54x is less rigid than the fixed portions 54a and 54b and the link arm portions 54s and 54t, and is easily elastically deformed and bent. The correction lens holding frame 52 is translated in the vertical direction with respect to the holding table 56.
[0059]
As shown in FIG. 9B, the holding base 56 includes a main body portion 56 c that is disposed between the correction lens holding frame 52 and the base 60. Although not shown, the main body portion 56c has a hole in the left and right so as not to block the optical path, and a hole into which the battery chamber 18 is inserted in the center. As shown in FIG. 9, reinforcing ribs 56 a and 56 b that stand around the correction lens holding frame 52 and extend to the same height as the correction lens holding frame 52 are provided upright on the left and right sides of the main body portion 56 c. Each of the reinforcing ribs 56a and 56b is provided with a protrusion 56k protruding left and right, and a V-groove 56v is formed at the tip thereof so as to receive a shape memory alloy string of a drive unit described later.
[0060]
As shown in FIG. 10B, the horizontal link plate 58 is disposed between the holding table 56 and the base 60 and constitutes a parallel link mechanism that swings left and right with one component. The horizontal link plate 58 is made of a thin leaf spring material, like the vertical link plate 54. As shown in FIG. 12, the horizontal link plate 58 has fixed portions 58s and 58t extending in the left and right directions connected to both ends of two link arms 58a and 58b extending vertically. Similar to the vertical link plate 54, the horizontal link plate 58 is bent substantially perpendicularly along the link arms 58a and 58b to the objective lens side, and the fixing portions 58s and 58t and the link arm portions 58a and 58b have an L-shaped cross section. The deformed portion 58x is constituted only by a narrow vertical surface, and this portion is elastically deformed. One fixing portion 58s is fixed to the holding base 56, and the other fixing portion 58t is fixed to the base 60 on the stationary system side, so that the holding base 58 moves in parallel to the left and right with respect to the base 60.
[0061]
As shown in FIG. 11, the base 60 has a plate shape, and has holes 60a and 60b through which the left and right optical paths pass, and a hole 60c through which the battery chamber 18 is inserted. A hook 60x for locking the pressing spring 53 is provided in the hole 60c. As shown in FIG. 10C, on the surface on the eyepiece lens side, the holding portion 60t of the above-described reference surface 60s and a position sensor (photo reflector) 80 that detects the vertical and horizontal movement amounts of the correction lens holding frame 52 are provided. And are provided. In addition, a support portion 60k that slidably supports a guide shaft 70 for locking the correction lens holding frame 52 so as not to move is provided. Although not shown, holes for attaching the vertical drive unit are provided on the upper and lower side surfaces, and attachment holes for attaching the horizontal drive unit are provided on the left and right side surfaces.
[0062]
Four pressing springs 53 are hung between the correction lens holding frame 52 and the base 60 so that the reference protrusion 52z of the correction lens holding frame 52 is pressed against the reference surface 60s of the base 60 by its own spring force. . Thereby, the correction lens holding frame 52 moves in a plane.
[0063]
As shown in FIG. 10C, the lock mechanism is fitted to the guide shaft 70 extending in the optical axis direction from the base 60 and the guide shaft 70 so as to be capable of thrust movement, and the correction lens holding frame 52 is attached to the tapered portion at the tip. A lock pin 72 that holds the correction lens holding frame 52 so as not to move, a lock spring 74 that presses the lock pin 72 toward the base 60, and a lock release lever 76 that moves the lock pin 72 away from the correction lens holding frame 52. including.
[0064]
The correction lens holding frame 52 is locked by the lock pin 72 in the non-correction state, and is unlocked in the correction state, but the movement amount is regulated by the guide shaft 70. There is a transmission mechanism (not shown) between the camera shake prevention button 14 and the lock pin 72, and the pressing movement of the camera shake prevention button 14 is converted into the movement of the lock release lever 76 in the lock pin release direction to release the lock. Can be done.
[0065]
Next, the configuration of the drive unit will be described with reference to the drawings.
[0066]
The drive unit is a unit obtained by fixing both ends of the shape memory alloy cord of the shape memory alloy to the support.
[0067]
As shown in FIGS. 3 and 4, the support is formed by integrally molding a resin 150 with two solder terminals 110 and 120. The support may be formed by bonding and bonding two solder terminals and an insulator. The solder terminals 110 and 120 are integrated in a state of being separated from each other and insulated from each other. A shape memory alloy string 102 of shape memory alloy is fixed to the solder terminals 110 and 120 by a method described later.
[0068]
The shape memory alloy string 102 is slack when the drive unit 100 is not attached, and in the attached state, the intermediate portion is pressed against the driven body and folded back into a "<" shape. In order to realize this “<” character, the support is generally formed in a “U” shape or an arcuate shape, and the shape memory alloy string 102 is attached to both ends on the opening side, and is surrounded by the support. Wrapped on the side.
[0069]
As shown in FIG. 3, mounting holes 116 and 126, positioning holes 128, and connection terminals 112 and 122 are formed in the connecting portion of the solder terminals 110 and 120, and are used as mounting surfaces for mounting the drive unit 100. It is done. Further, a through hole 108 is provided, and when the drive unit 100 is attached, the engagement between the shape memory alloy string 102 and the V grooves 52v and 56v of the projections 52k and 56k can be easily confirmed from the through hole 108. It is like that.
[0070]
Both end portions on the opening side of the drive unit 100 have the same plane substantially parallel to the mounting surface as receiving surfaces, and key holes 114 and 124 and guides 115 and 125 are formed in that portion. The key holes 114 and 124 are portions penetrating the solder terminals 110 and 120 in a key hole shape, and include round hole portions 114a and 124a and linear portions 114c and 124c extending from the round hole portions 114a and 124a to the mounting surface side. Consists of. The guides 115 and 125 are shallow grooves extending from the round hole portions 114a and 124a of the key holes 114 and 124 to the side opposite to the mounting surface.
[0071]
The ball 130 is press-fitted into the round hole portions 114 a and 124 a of the key hole 124 together with the shape memory alloy string 102, and the shape memory alloy string 102 is attached by fitting the ball 130. A wedge may be used instead of the ball 130.
[0072]
FIG. 5 is a front view of the camera shake correction unit 50 viewed from the objective lens side with the body 11 removed. FIG. 6 is a camera front view of the camera shake correction unit 50 viewed from the objective lens side with the objective lens barrel 32 removed. FIG. 7 is a front view, FIG. 7 is a sectional view taken along line VII-VII in FIG. 5, and FIG. 8 is a side view seen along line VIII-VIII in FIG .
[0073]
First, the shape memory alloy string 102 is stretched with low tension so as to pass through the guides 115 and 125 on the receiving surfaces at both ends on the opening side of the support.
[0074]
Next, as shown in FIG. 4A, the center of the shape memory alloy string 102 is lowered to a predetermined depth by the length adjusting tensioner 180.
[0075]
Then, as shown in FIG. 4 (b), the ball 130 is simultaneously driven into a predetermined depth into the round hole portions 114a and 124a of the key holes 114 and 124 from the inside of the "<" shape of the shape memory alloy string 102, The shape memory alloy string 102 is fixed.
[0076]
The attached shape memory alloy string 102 is used in a state where it crosses the round hole portions 114a and 124a of the key hole 124 in the thickness direction, passes through the straight portions 114c and 124c, and enters the inside of the support again. The
[0077]
The camera shake correction unit 50 requires one drive unit for the direction in which the correction lens 51 is moved. As shown in FIGS. 5 to 8, a total of four drive units 100 a to 100 d are assembled in the camera shake correction unit 50. Installed later.
[0078]
FIG. 5 is a front view of the camera shake correction unit 50 viewed from the objective lens side with the body 11 removed. FIG. 6 is a camera front view of the camera shake correction unit 50 viewed from the objective lens side with the objective lens barrel 32 removed. FIG. 7 is a sectional view taken along line VII-VII in FIG. 5, FIG. 8 is a side view seen along line VIII-VIII in FIG.
[0079]
As shown in FIG. 6, the drive units 100 c and 100 d for lateral drive are attached so as to follow the R portion on the outer periphery of the camera shake correction unit 50. As shown in FIG. 5, the drive units 100 a and 100 b for vertical drive are attached so as to enter the valleys of the two objective lens barrels 32 arranged side by side. At this time, the drive units 100c and 100d for lateral drive have the direction of the “<” shape (the surface including the “<” shape portion of the shape memory alloy string 102 of the shape memory alloy) as the moving plane of the correction lens 51. The driving units 100a and 100b for vertical driving have a “<” shape in a direction perpendicular to the moving plane.
[0080]
That is, the correction lens holding frame 52 that moves in an arbitrary direction on the reference plane of the base 60 has the driving units 100a and 100b whose driving directions are up and down, and the holding base 56 that moves only in the left and right directions has a driving direction that is left and right. Drive units 100c and 100d face each other and are held on the base 60. In the drive unit pair 100a, 100b that drives the correction lens holding frame 52 up and down, the extending direction of the shape memory alloy string of the shape memory alloy and the reference plane on which the correction lens holding frame 52 moves are perpendicular to each other. Also, the drive unit pair 100c, 100d that drives the holding base 56 left and right is different from the drive unit pair 100a, 100b that drives up and down, and the extending direction of the shape memory alloy string of the shape memory alloy is parallel to the reference plane. .
[0081]
Further, as described above, the shape memory alloy string 102 can be easily checked from the through hole 108 on the mounting surface of the drive unit 100 to the V grooves 52v and 56v of the projections 52k and 56k of the camera shake correction unit 50. However, as for the drive units 100c and 100d for lateral drive, as shown in FIG. 6, the projection 56 of the holding base 56 penetrates the through hole of the mounting surface, and the movement of the holding base 56 in the optical axis direction. Is now restricted.
[0082]
FIG. 13 is a block diagram illustrating a configuration of a control system that performs camera shake correction of the binoculars 10.
[0083]
A control circuit 90 that controls the control is connected to a position sensor 80, an acceleration sensor 82, drive units 100a to 100d, and a lock release detection switch 14, and power is supplied from the battery 2. .
[0084]
As described above, the position sensor 80 detects the position of the correction lens holding frame 52 in the camera shake correction unit 50. The acceleration sensor 82 is, for example, a gyro sensor and is disposed at an appropriate position in the body 11 and detects shake data of the binoculars 10 due to hand shakes of the binoculars 10 or the like. The main switch 15 is turned on in conjunction with the unlocking of the camera shake correction unit 50 by the operation of the camera shake prevention button 14. That is, when the camera shake prevention button 14 is operated, the lock pin 70 of the camera shake correction unit 50 is pulled up by a transmission mechanism (not shown), the locked state of the camera shake correction unit 50 is released, and the correction lens 51 can be moved. it can. The main switch 15 is provided in the middle of this transmission mechanism and is turned on at the last part of the unlocking stroke. The control circuit 90 includes a servo circuit for driving the drive units 100a to 100d for camera shake correction. The control circuit 90 appropriately drives the drive units 100a to 100d from the output of the acceleration sensor 82 and the output of the position sensor 80, and moves the correction lens 50 to a position where the observation image by the binoculars 10 is not blurred.
[0085]
Next, a specific operation will be described.
[0086]
When the camera shake correction unit 50 is unlocked by operating the camera shake prevention button 14 on the upper surface of the binoculars and the main switch 15 is turned on, the control circuit 90 starts to operate and is applied to the shape memory alloy strings of the drive units 100a to 100d. The voltage to be determined is determined and the voltage is applied.
[0087]
The shape memory alloy string to which a voltage is applied generates Joule heat due to its own resistance value. This heat shrinks to its memorized length. Because of the character “ku”, the moving amount is efficiently scaled to a predetermined magnification. Due to the shrinkage of the shape memory alloy string, the opening of the “<” character becomes large, and the correction lens holding frame 52 or the holding stand 56 moves away from the drive unit to which the voltage is applied. The magnification M = δ / λ of the correction lens movement stroke δ with respect to the contraction length λ of the shape memory alloy string is M = cos θ / k− (1-sin ² θ / k ² ) ^1/2 (1)
It is.
Here, θ is half of the angle opened in the shape of “<” and k is the contraction rate of the shape memory alloy string.
[0088]
The shape memory alloy string of the drive unit opposite to the drive unit to which the voltage is applied to the shape memory alloy string is pushed at the center by the moving correction lens holding frame 52 or holding table 56 and extends beyond the elastic range. . The driving force is the resultant force of the shape memory alloy string tension due to heating in the “<” shape. On the other hand, the resistance force includes the deformation resistance of the opposing shape memory alloy string, the friction resistance when the correction lens holding frame 52 moves on the base 60, the moving direction component of the restoring force of the pressing spring 53, and the parallel link mechanism. 54 and 58, which is the sum of the spring forces of the leaf springs constituting the springs.
[0089]
In the case of lateral vibration, the resistance force that pulls the shape memory alloy strings of the drive units 100a and 100b for longitudinal drive in the lateral direction is added to the resistance force of the lateral vibration. This resistance is such that the linear shape memory alloy string is bent slightly in the lateral direction, and its influence is slight.
[0090]
When there is a vertical vibration component, one of the drive units 100a and 100b for vertical drive is selected and energized by the control circuit 90. The energized shape memory alloy string contracts and pushes the correction lens holding frame 52 toward the center of gravity. The correction lens holding frame 52 pressed by the shape memory alloy string of the drive unit for vertical drive moves substantially vertically without being rotated by the vertical link plate 54. At this time, in the vertical link plate 54, the fixing portion 54b on the correction lens holding frame 52 side moves in parallel, the angles of the upper and lower two link arms 54s and 54t change, and the fixing portion 54ba on the holding base 56 side does not move. . The displacement portions 54x at both ends of the link arms 54s and 54t bend in the opposite direction and bend. The link arms 54s and 54t and the fixing portions 54a and 54b having an L-shaped cross section are hardly deformed because the rigidity is extremely high.
[0091]
If there is a lateral vibration component, the control circuit 90 selects and energizes one of the drive units 100c and 100d for lateral drive. The shape memory alloy string of the drive unit for the lateral drive that is energized contracts and pushes the holding table 56 toward the center of gravity. The holding base 56 pressed by the shape memory alloy string of the driving unit for the lateral drive, the vertical link plate 54 held by the strap, and the correction lens holding frame 52 are substantially left and right without being rotated by the horizontal link plate 58. Moving. At this time, in the horizontal link plate 58, the fixing portion 56a on the holding base 56 side moves in parallel, the angles of the left and right link arms 56s and 56t change, and the fixing portion 56b on the base 60 side does not move. The displacement portions 56x at both ends of the link arms 56s and 56t are bent in the opposite directions and bent. The link arms 56s and 56t having the L-shaped cross section and the fixing portions 56a and 56b are hardly deformed due to their high rigidity.
[0092]
Therefore, the gaze position of the objective lens 30 continues to hold the same place on both the left and right, regardless of the vibration of the binoculars 10, regardless of whether there is vertical or horizontal vibration.
[0093]
When the hand shake operation button 14 is released, first, the main switch 15 is turned off, the power supply to the control circuit 90 is cut off, and the operation is stopped. When the lock pin 72 further approaches the base 60 side, the movable range of the correction lens holding frame 52 is narrowed, and then the holding frame 52 is guided to the initial position by its own taper, and finally the correction lens holding frame 52 is operated. Disable (lock).
[0094]
In addition, this invention is not limited to the said embodiment, It can implement in another various aspect.
[0095]
For example, instead of the configuration in which the reference protrusion 52z of the correction lens holding frame 52 and the reference surface 60s of the base 60 are in direct contact with each other, as shown in the enlarged view of the main part in FIG. The steel ball 200 may be disposed between the base surface 60s of the base 60. In this case, a recess 60t is preferably formed in the base 60 so that the steel ball 200 does not come out, and the bottom surface of the recess 60t is used as a reference surface 60s. Accordingly, it is possible to reduce friction between the reference protrusion 52z and the reference surface 60s while maintaining the parallel accuracy of the correction lens holding frame 52 with respect to the reference surface 60s of the base 60. Therefore, the correction lens holding frame 52 can be smoothly translated with a small force with respect to the base 60, and effects such as speeding up of camera shake correction and power saving can be obtained.
[0096]
For example, the camera shake prevention mechanism 50 and the drive units 100a to 100d can be used to support the image sensor in an image pickup apparatus that prevents camera shake by moving the image sensor in accordance with the movement of the subject image.
[0097]
【The invention's effect】
By adopting the press-fitting method using a ball, the size of the terminal portion was reduced and the cost could be minimized. Further, by making the fitting hole portion into a keyhole shape, the holding pressure of the shape memory alloy string can be reduced, and the base plate can be prevented from being broken from the hole portion during press-fitting.
[0098]
By unitizing, it was possible to mechanize assembling and holding the shape memory alloy string, which required length accuracy, and to simplify the incorporation into equipment. In addition, since the drive unit is configured in a “U” shape, it can be efficiently arranged in an annular device, and the device can be downsized.
[0099]
Since the shape memory alloy string is bent and driven in the shape of “Ku”, the zoom mechanism that was previously required on the device side can be omitted, and downsizing and cost reduction of the mounted device can be achieved. It was.
[Brief description of the drawings]
FIG. 1 is an external view of binoculars according to an embodiment of the present invention.
FIG. 2 is a block layout diagram of the binoculars of FIG.
FIG. 3 is a plan view of a drive unit.
4 is an explanatory diagram of a method for assembling the drive unit of FIG. 3;
FIG. 5 is an explanatory diagram of an arrangement of drive units.
FIG. 6 is an explanatory diagram of the arrangement of drive units.
7 is a cross-sectional view taken along line VII-VII in FIG.
FIG. 8 is a side view taken along line VIII-VIII in FIG. 6;
FIG. 9 is an external view and a cross-sectional view of a correction unit.
10 is a perspective view and a cross-sectional view of a main part of the correction unit in FIG. 9. FIG.
11 is an external view of the correction unit of FIG. 9 as viewed from the objective lens side.
12 is an external view of the correction unit shown in FIG. 9 when the base is removed from the objective lens side.
FIG. 13 is a block diagram of a control system.
FIG. 14 is a conceptual diagram of a parallel link mechanism.
FIG. 15 is a conceptual diagram of deformation of the parallel link mechanism.
FIG. 16 is an enlarged view of a main part of a modified example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 100 Drive unit 102 Shape memory alloy string 108 Through hole 110 Solder terminal (base plate, support body, support plate)
112 Connection terminal 114 Key hole (hole, support part)
114a Round hole (round hole)
114c Straight line part (slit part)
115 Guide 120 Solder terminal (base plate, support, support plate)
122 Connection terminal 124 Key hole (hole, support part)
124a Round hole (round hole)
124c Straight part (slit part)
125 guide 130 ball
150 Resin (support, bonding part)

Claims (10)

A support having first and second support portions;
Both ends are held by the first and second support parts, and a shape memory alloy string having a dimension longer than the distance between the first and second support parts,
The support is
Conductive first and second support plates provided with the first and second support portions, respectively;
An insulative coupling portion that integrally couples the first and second support plates;
A drive unit, wherein the shape memory alloy string presses and drives a driven body by energization . The first and second support plates are metal base plates,
The first and second support portions are holes;
2. The drive unit according to claim 1, wherein the shape memory alloy string is press-fitted and held in the first and second support portions together with a ball or a wedge . The support has a space formed by retreating from the opening into a substantially “U” shape or an arcuate shape,
The drive unit according to claim 1, wherein the shape memory alloy string is disposed so as to cross the space. The support is
First and second ends formed with the first and second support portions, respectively;
A curved portion extending between the first and second ends in a substantially “U” shape or an arcuate shape, and having a mounting portion for mounting the drive unit at the center. The drive unit according to any one of claims 1 to 3.   5. The drive unit according to claim 4, wherein the first and second ends of the support are included in the same plane.   The drive unit according to claim 4 or 5, wherein a connection terminal connected to an external power source is provided in the vicinity of the attachment portion so as to allow a current to flow through the shape memory alloy string. The support is
2. A through hole through which an intermediate portion of the shape memory alloy string pressed against the driven body penetrates or approaches between the first and second support portions. The drive unit according to any one of 6. 8. The structure according to claim 1, wherein a movement amount of the driven body due to a change in the total length of the shape memory alloy string is larger than a change amount of the total length of the shape memory alloy string. The drive unit according to any one of the above.   The said support body is fixed to the moving member holding part holding a moving member, and the said moving member was equipped with the engaging part engaged at the approximate center of the said shape memory alloy string. The drive unit according to any one of 8.   The drive unit according to claim 9, wherein the moving member is a correction lens holding frame, the moving member holding portion is a base, and the engaging portion is a protrusion having a V-groove.

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