CN115685640A - Shaft member, method of manufacturing shaft member, and optical unit with shake correction function - Google Patents

Abstract

The invention provides a shaft member having a bead disposed at an end portion, which can easily dispose the center of the bead on the axis of the shaft member even if the shaft member is thin, and can easily perform fixing operation of the bead. The shaft member (18) has a cylindrical tube (22) and a spherical bead (23) fixed to one end of the tube (22). The outer diameter of the bead (23) is larger than the inner diameter of the tube (22). In the shaft member (18), the inner periphery of the end surface of the tube (22) is used to position the bead (23) so that the center of the bead (23) is arranged on the axial center of the shaft member (18). In addition, when the ball (23) is fixed to one end of the tube (22) in the shaft member (18), the ball (23) can be temporarily fixed to one end of the tube (22) by, for example, sucking air on the inner peripheral side of the tube (22) from the other end of the tube (22).

Description

Shaft member, method of manufacturing shaft member, and optical unit with shake correction function

Technical Field

The present invention relates to a shaft member used as a support shaft for rotatably supporting a predetermined object to be rotated, a rotation shaft of a motor, and the like. The present invention also relates to a method for manufacturing the shaft member and an optical unit with a shake correction function having the shaft member.

Background

Conventionally, a motor having a shaft member including a rotating shaft and a bead fixed to an end of the rotating shaft is known (for example, see patent document 1). In the motor described in patent document 1, a bead is fixed by adhesion or welding to an end portion of a rotating shaft formed in a stepped, elongated cylindrical shape. A recess recessed in the axial direction of the rotary shaft is formed in the end surface of the rotary shaft, and the side surface of the recess is a conical surface. A ball fixed to an end of the rotating shaft is in contact with a side surface of the recess. In this motor, the beads are positioned with respect to the rotating shaft such that the centers of the beads are disposed on the axial center of the rotating shaft (i.e., such that the beads are disposed on the axial center of the shaft member) by contacting the beads with the side surfaces of the recess.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2014-39411

Disclosure of Invention

In the case of the motor described in patent document 1, if the shaft member including the rotating shaft and the beads is made thin, it may be difficult to accurately form the recess portion in the end surface of the rotating shaft. For example, if the shaft member is made thin and the outer diameter of the rotating shaft is 1mm or less, it may be difficult to accurately form the recess on the end surface of the rotating shaft. Therefore, in the case of the motor described in patent document 1, if the shaft member is made thin, it may be difficult to easily dispose the center of the bead on the axial center of the shaft member. In the case of this motor, when the shaft member is made thin, the rotating shaft becomes thin and the beads become small, and the rotating shaft and the beads become difficult to handle, so that the fixing work of the beads to the rotating shaft may become complicated.

Therefore, an object of the present invention is to provide a shaft member having a bead disposed at an end portion thereof, which can easily dispose the center of the bead on the axial center of the shaft member even when the shaft member is made thin, and which can easily perform a fixing operation of the bead. Another object of the present invention is to provide a method for manufacturing the shaft member. Another object of the present invention is to provide an optical unit with a shake correction function, which includes the shaft member.

In order to solve the above-described problems, a shaft member according to the present invention includes a cylindrical tube and a spherical bead fixed to one end of the tube, and the outer diameter of the bead is larger than the inner diameter of the tube.

In the shaft member of the present invention, a bead having an outer diameter larger than an inner diameter of a tube is fixed to one end of the tube formed in a cylindrical shape. Therefore, in the present invention, even if the end surface of the pipe is not provided with the recess, the bead can be positioned so that the center of the bead is disposed on the axial center of the shaft member by utilizing the inner peripheral side of the end surface of the pipe. Therefore, in the present invention, even if the shaft member is made thin, the center of the bead can be easily arranged on the axial center of the shaft member.

In the present invention, when the bead is fixed to one end of the tube, for example, air on the inner peripheral side of the tube is sucked from the other end of the tube, whereby the bead can be temporarily fixed to the one end of the tube. Therefore, in the present invention, even if the shaft member is thinned, the tube is thinned, and the beads are made smaller, making it difficult to handle the tube and the beads, the fixing work of the beads to the tube can be easily performed.

In the present invention, it is preferable that the tube and the bead are formed of the same metal material, and the bead is fixed to the tube by welding. With this configuration, the bead can be relatively easily fixed to one end of the tube.

The method for manufacturing the shaft member of the present invention includes, for example, a bead fixing step of fixing a bead to one end of a tube, and in the bead fixing step, the bead is permanently fixed to the one end of the tube in a state where air on the inner peripheral side of the tube is drawn from the other end of the tube and the bead is temporarily fixed to the one end of the tube. When the shaft member is manufactured by this manufacturing method, even if the shaft member is made thin, the tube is made thin, and the beads are made small, making it difficult to handle the tube and the beads, the fixing work of the beads to the tube can be easily performed.

The shaft member of the present invention can be used for an optical unit with a shake correction function having a shake correction function for correcting a shake of an optical image. The optical unit with a shake correction function includes, for example: a reflection unit having a reflection member on which a reflection surface for reflecting light incident from the outside is formed; a fixed body holding the reflection part; a drive mechanism for rotating the reflection section relative to the fixed body; and a spring member that biases the reflecting portion, wherein the fixing body includes the shaft member of the present invention, the shaft member protrudes toward a center side of the reflecting portion, a part of the bead constitutes a tip portion of the shaft member, the bead is disposed on the center side of the reflecting portion, a disposition recess portion in which at least a part of the shaft member is disposed is formed in the reflecting portion, a contact portion that contacts the bead is formed in the disposition recess portion, the spring member biases the reflecting portion with respect to the fixing body in a direction in which the contact portion contacts the bead, and the bead serves as a rotation fulcrum of the reflecting portion with respect to the fixing body.

In the optical unit with shake correction function, even if the shaft member is thin, the center of the bead can be easily arranged on the axis of the shaft member, and the fixing operation of the bead can be easily performed. In the optical unit with shake correction function, a part of the beads constitutes a tip portion of the shaft member protruding toward the center side of the reflection portion, and the beads are arranged on the center side of the reflection portion. The reflecting portion is formed with an arrangement recess in which at least a part of the shaft member protruding toward the center side of the reflecting portion is arranged, and a contact portion contacting the bead is formed in the arrangement recess, and the bead serves as a rotation fulcrum of the reflecting portion with respect to the fixed body. Therefore, in the optical unit with shake correction function, the pivot point of the reflecting portion with respect to the fixed body can be brought close to the center of gravity of the reflecting portion.

In the optical unit with shake correction function, the beads serve as the pivot points of the reflecting portion with respect to the fixed body, and therefore the number of members constituting the pivot points of the reflecting portion with respect to the fixed body can be reduced. In the optical unit with shake correction function, the spring member biases the reflecting portion with respect to the fixed body in the direction in which the contact portion contacts the bead, so that the reflecting portion can be returned to the predetermined origin position with respect to the fixed body by the biasing force of the spring member when the driving force of the driving mechanism is not applied.

In the present invention, for example, the axial direction of the shaft member is orthogonal to the first direction which is the optical axis direction of the light incident on the reflection surface. In this case, the optical unit with the shake correction function can be made smaller in the optical axis direction of the light incident on the reflection surface than in the case where the axial direction of the shaft member is parallel to the first direction.

In the present invention, for example, the drive mechanism includes: a first drive mechanism which rotates the reflection part relative to the fixed body by taking the first direction as the axial direction of rotation; and a second drive mechanism that rotates the reflection unit relative to the fixed body in an axial direction in which a second direction orthogonal to the axial direction of the shaft member and the first direction is a rotational axial direction.

In the present invention, it is preferable that the first drive mechanism includes: a first driving magnet and a first driving coil arranged to face each other in a second direction; and a first magnetic sensor for detecting a rotation amount of the reflecting portion with respect to the fixed body in a rotation direction in which the first direction is an axial direction of rotation, the second driving mechanism including: a second driving magnet and a second driving coil arranged to face each other in the first direction; and a second magnetic sensor for detecting a rotation amount of the reflecting portion with respect to the fixed body in a rotation direction in which the second direction is an axial direction of rotation, wherein the first magnetic sensor is disposed to face the first driving magnet in the second direction, the second magnetic sensor is disposed to face the second driving magnet in the first direction, the first driving magnet and the second driving magnet are polarized to two poles in the axial direction of the shaft member, and when the reflecting portion is disposed at a predetermined origin position with respect to the fixed body, at least one of a polarization position of the first driving magnet and a polarization position of the second driving magnet is disposed at the same position as the beads in the axial direction of the shaft member.

With this configuration, it is possible to suppress at least one of a variation in the output signal of the first magnetic sensor when the reflecting unit is rotated from the origin position with respect to the fixed body with the second direction as the axial direction of rotation and a variation in the output signal of the second magnetic sensor when the reflecting unit is rotated from the origin position with respect to the fixed body with the first direction as the axial direction of rotation. Therefore, at least one of the detection accuracy of the first magnetic sensor for the rotation amount of the reflection unit and the detection accuracy of the second magnetic sensor for the rotation amount of the reflection unit can be improved.

Effects of the invention

As described above, according to the present invention, even if the shaft member is made thin, the center of the bead can be easily arranged on the axis of the shaft member, and the fixing operation of the bead can be easily performed.

Drawings

Fig. 1 is a perspective view of an optical unit with a shake correction function according to an embodiment of the present invention.

Fig. 2 is a perspective view of a smartphone incorporating the optical unit with shake correction function shown in fig. 1.

Fig. 3 is a schematic diagram for explaining the configuration of a camera built in the smartphone shown in fig. 2.

Fig. 4 is an exploded perspective view of the optical unit with a shake correction function shown in fig. 1.

Fig. 5 is a longitudinal sectional view of the optical unit with a shake correction function shown in fig. 1.

Fig. 6 is a cross-sectional view of the optical unit with shake correction function shown in fig. 1.

Fig. 7 is a plan view of the shaft member, the first driving magnet, and the second driving magnet shown in fig. 4, taken out.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Structure of optical Unit with Shake correction function)

Fig. 1 is a perspective view of an optical unit 1 with a shake correction function according to an embodiment of the present invention. Fig. 2 is a perspective view of a smartphone 2 incorporating the optical unit 1 with a shake correction function shown in fig. 1. Fig. 3 is a schematic diagram for explaining the configuration of the camera 3 built in the smartphone 2 shown in fig. 2. Fig. 4 is an exploded perspective view of the optical unit 1 with a shake correction function shown in fig. 1. Fig. 5 is a longitudinal sectional view of the optical unit 1 with a shake correction function shown in fig. 1. Fig. 6 is a cross-sectional view of the optical unit 1 with shake correction function shown in fig. 1. Fig. 7 is a plan view of the shaft member 18 and the driving magnets 27 and 31 shown in fig. 4, taken out.

The optical unit 1 with shake correction function (hereinafter referred to as "optical unit 1") of the present embodiment has a shake correction function for correcting shake of an optical image. The optical unit 1 is a small unit built in a smartphone 2 (see fig. 2), for example. The optical unit 1 constitutes a part of a camera 3 (see fig. 3) built in the smartphone 2. The optical unit 1 may be incorporated in a portable device or the like other than the smartphone 2.

As shown in fig. 3, the camera 3 includes: a lens 4, into which light from the outside of the smartphone 2 is incident; and a substrate 6 on which the imaging element 5 is mounted. The optical axis L1 of the lens 4 is orthogonal to a normal line L2 passing through the center of the imaging surface of the imaging element 5. The optical unit 1 is disposed between the lens 4 and the image pickup device 5 on an optical path from the lens 4 toward the image pickup device 5. A lens 7 is disposed between the optical unit 1 and the image pickup device 5. The optical axis of the lens 7 coincides with the normal L2.

The optical unit 1 includes a prism 10 as a reflection member, and the prism 10 is formed with a reflection surface 10a that reflects light incident from the outside. The light having passed through the lens 4 is incident on the reflection surface 10a. The reflection surface 10a reflects the light incident on the reflection surface 10a via the lens 4 toward the image pickup device 5. The reflecting surface 10a bends the optical axis of light incident on the reflecting surface 10a by substantially 90 °. The light reflected by the reflection surface 10a passes through the lens 7, and the light passing through the lens 7 enters the imaging element 5.

In the following description, the optical axis direction of light incident on the reflection surface 10a (i.e., the direction of the optical axis L1 of the lens 4, the Z direction in fig. 1, etc.) is defined as the vertical direction, the direction of the normal L2 to the imaging surface of the imaging element 5 (the X direction in fig. 1, etc.) is defined as the front-rear direction, and the Y direction in fig. 1, etc. perpendicular to the vertical direction and the front-rear direction is defined as the left-right direction. In addition, the side (Z1 direction side in fig. 1 and the like) on which the lens 4 is disposed with respect to the optical unit 1 in the vertical direction is referred to as "upper" side, and the opposite side, that is, the Z2 direction side in fig. 1 and the like is referred to as "lower" side. In the front-rear direction, the side on which the imaging element 5 is disposed with respect to the optical unit 1 (the X1 direction side in fig. 1 and the like) is referred to as the "front" side, and the opposite side, that is, the X2 direction side in fig. 1 and the like is referred to as the "rear" side.

The optical unit 1 includes, in addition to the prism 10, a holder 11 for fixing the prism 10 and a fixing plate 12 fixed to the holder 11. In the present embodiment, the reflecting portion 13 is constituted by the prism 10, the holder 11, the fixing plate 12, and the like. That is, the optical unit 1 includes a reflection unit 13 having the prism 10, the holder 11, the fixing plate 12, and the like. Further, the optical unit 1 includes: a fixing body 14 for holding the reflection part 13; a drive mechanism 15 for rotating the reflection unit 13 with respect to the fixed body 14; and a tension coil spring 16 as a spring member that biases the reflection section 13. The fixed body 14 includes a frame 17 and a shaft member 18 fixed to the frame 17. The optical unit 1 corrects the blur of the optical image by performing the rotational operation of the reflection unit 13 with respect to the fixed body 14.

The holder 11 is formed of a resin material. The holder 11 is formed with an inclined surface 11a (see fig. 5) to which the prism 10 is fixed. The inclined surface 11a is inclined downward toward the front side. The inclined surface 11a is formed between the front lower end and the rear upper end of the holder 11. The rear surface of the retainer 11 is formed as a plane substantially orthogonal to the front-rear direction. Recesses 11b are formed on both lateral side surfaces of the holder 11, and a drive magnet 27 described later constituting the drive mechanism 15 is disposed in the recesses 11 b. The recess 11b is recessed inward in the left-right direction. A recess 11c is formed in the lower surface of the holder 11, and a drive magnet 31, which will be described later, constituting the drive mechanism 15 is disposed in the recess 11 c. The recess 11c is recessed toward the upper side.

The holder 11 is formed with a through hole 11d penetrating the holder 11 in the front-rear direction. An opening penetrating the rear end of the hole 11d is formed in the center of the rear surface of the holder 11. An annular recess 11e is formed in the rear surface of the holder 11. The recess 11e is recessed toward the front side. The recess 11e is formed in an annular shape surrounding the opening at the rear end of the through-hole 11d. The front end side portion of the through hole 11d is closed by the fixing plate 12. In the present embodiment, the portion of the through-hole 11d on the rear side of the fixing plate 12 and the fixing plate 12 constitute an arrangement recess 21 in which a part of the shaft member 18 is arranged. That is, the reflection portion 13 is formed with an arrangement recess 21 in which a part of the shaft member 18 is arranged.

The arrangement recess 21 includes a small diameter portion 21a constituting a front end portion of the arrangement recess 21, a large diameter portion 21b constituting a rear end portion of the arrangement recess 21, and a tapered portion 21c arranged between the small diameter portion 21a and the large diameter portion 21b in the front-rear direction. The small diameter portion 21a and the large diameter portion 21b are circular holes having a constant inner diameter. The large diameter portion 21b has an inner diameter larger than that of the small diameter portion 21 a. The tapered portion 21c is a circular hole having a truncated cone shape in which the inner diameter gradually decreases toward the front side. The inner diameter of the tip of the tapered portion 21c is equal to the inner diameter of the small-diameter portion 21a, and the inner diameter of the rear end of the tapered portion 21c is equal to the inner diameter of the large-diameter portion 21 b.

The fixing plate 12 is formed of a metal material. For example, the fixing plate 12 is formed of stainless steel. The fixed plate 12 includes an annular flat plate-like fixed portion 12a fixed to the holder 11 and a curved plate-like contact portion 12b connected to an inner peripheral end of the fixed portion 12 a. The fixed portion 12a is fixed to the holder 11 so that the thickness direction thereof substantially coincides with the front-rear direction. The contact portion 12b is formed in a substantially hemispherical shape bulging toward the front side, and the rear surface of the contact portion 12b is formed in a concave curved surface recessed toward the front side. Specifically, the rear surface of the contact portion 12b is a concave curved surface having a hemispherical shape. The tip of the shaft member 18 contacts the contact portion 12b. That is, the contact portion 12b that contacts the distal end portion of the shaft member 18 is formed in the arrangement recess 21.

As described above, the fixed body 14 has the frame 17 and the shaft member 18. The frame 17 is formed of a resin material. The frame 17 includes: two flat plate-like side surface portions 17a constituting lateral surfaces of the frame 17 in the left-right direction; a flat bottom surface portion 17b constituting a bottom surface (lower surface) of the frame 17; a flat-plate-shaped back surface portion 17c constituting the back surface of the frame 17; and a shaft holding portion 17d projecting from the rear surface portion 17c toward the front side. The reflection portion 13 is disposed between the two side surface portions 17a in the left-right direction. The reflection unit 13 is disposed above the bottom surface 17b and in front of the back surface 17 c.

The side surface portion 17a is formed with a through hole 17e for disposing a driving coil 28, which will be described later, constituting the driving mechanism 15. The bottom surface portion 17b is formed with a through hole 17f for disposing a driving coil 32 described later constituting the driving mechanism 15. The shaft holding portion 17d projects forward from the center of the back surface portion 17 c. The shaft holding portion 17d is formed in a substantially cylindrical shape, and a shaft holding hole 17g penetrating in the front-rear direction is formed in the shaft holding portion 17d and the back surface portion 17 c. The shaft holding hole 17g is a circular hole having a constant inner diameter. An annular recess 17h is formed in the front surface of the rear surface portion 17 c. The recess 17h is recessed toward the rear side. The recess 17h is formed in an annular shape surrounding the shaft holding portion 17d.

The shaft holding portion 17d is composed of a first holding portion 17j constituting a front portion of the shaft holding portion 17d and a second holding portion 17k constituting a rear portion of the shaft holding portion 17d. The outer diameter of the first holding portion 17j is constant. The outer diameter of the second holding portion 17k gradually becomes larger toward the rear side. The outer diameter of the tip of the second holding portion 17k is equal to the outer diameter of the first holding portion 17 j. The first holding portion 17j is disposed in the disposition recess 21. Specifically, the first holding portion 17j is arranged on the inner peripheral side of the large diameter portion 21 b.

The shaft member 18 includes a cylindrical tube 22 and a spherical bead (ball) 23 fixed to one end of the tube 22. The shaft member 18 of the present embodiment is constituted by 1 tube 22 and 1 bead 23. The tube 22 and the bead 23 are formed of a metal material. In the present embodiment, the tube 22 and the bead 23 are formed of the same metal material. For example, the tube 22 and the bead 23 are formed of stainless steel.

The tube 22 is, for example, a tube used as an injection needle, and the tube 22 is tapered. The beads 23 are, for example, beads used for small bearings, and the beads 23 are small. That is, the shaft member 18 as a whole becomes thin. For example, the outer diameter of the tube 22 is about 0.5 to 0.7 (mm). The outer diameter of the bead 23 is larger than the inner diameter of the tube 22. In addition, the outer diameter of the bead 23 is smaller than the outer diameter of the tube 22. The outer diameter of the bead 23 may be equal to the outer diameter of the tube 22.

The bead 23 is fixed to the front end of the tube 22. Further, a bead 23 is welded and fixed to the tip of the tube 22. The beads 23 are welded to the front end of the tube 22 at two locations in the circumferential direction of the tube 22, for example. The manufacturing process of the shaft member 18 includes a bead fixing step of fixing the bead 23 to the distal end (one end) of the tube 22, in which air on the inner peripheral side of the tube 22 is sucked from the proximal end (the other end) of the tube 22, and the bead 23 is permanently fixed to the distal end of the tube 22 by welding in a state where the bead 23 is temporarily fixed to the distal end of the tube 22.

A part of the bead 23 constitutes a tip portion of the shaft member 18. Specifically, the hemispherical portion of the bead 23 disposed on the distal end side of the shaft member 18 constitutes the distal end portion of the shaft member 18, and the distal end portion of the shaft member 18 is formed in a hemispherical shape. That is, the surface of the shaft member 18 on the distal end side is spherical (specifically, hemispherical).

The shaft member 18 is disposed so that the axial direction thereof (i.e., the axial direction of the tube 22) coincides with the front-rear direction. That is, the axial direction of the shaft member 18 coincides with the front-rear direction and is orthogonal to the vertical direction. In the present embodiment, the axial center of the shaft member 18 (i.e., the axial center of the tube 22) coincides with the normal line L2. The vertical direction (Z direction) of the present embodiment is a first direction which is the optical axis direction of light incident on the reflection surface 10a, and the horizontal direction (Y direction) is a second direction orthogonal to the front-rear direction which is the axial direction of the shaft member 18 and the vertical direction which is the first direction.

The front end of the shaft member 18 is disposed on the front side, and the base end of the shaft member 18 is disposed on the rear side. The shaft member 18 is press-fitted into the shaft holding hole 17g and fixed to the back surface portion 17c and the shaft holding portion 17d. The front end side portion of the shaft member 18 protrudes further forward than the shaft holding portion 17d. The distal end portion of the shaft member 18 projecting further toward the front than the shaft holding portion 17d is disposed on the inner peripheral side of the small diameter portion 21a and the tapered portion 21c of the arrangement recess 21.

As described above, the reflection portion 13 is disposed on the front side of the back surface portion 17 c. The arrangement recess 21 is recessed from the center of the rear surface of the holder 11 toward the front side, and the shaft member 18 projects toward the center side of the reflection portion 13. The bead 23 is disposed on the center side of the reflection portion 13. The contact portion 12b of the fixed plate 12 contacts the tip end portion of the shaft member 18. That is, the contact portion 12b contacts the bead 23. Specifically, the rear surface of the contact portion 12b having the concave curved surface is in contact with the bead 23 from the front side.

The shaft member 18 is disposed on the inner peripheral side of the tension coil spring 16. That is, the tension coil spring 16 is disposed on the outer peripheral side of the shaft member 18 so as to surround the shaft member 18. More specifically, the second holding portion 17k of the shaft holding portion 17d is disposed on the inner peripheral side of the tension coil spring 16, and a part of the shaft member 18 is disposed on the inner peripheral side of the tension coil spring 16. The tension coil spring 16 is disposed on the outer peripheral side of the second holding portion 17k so as to surround the second holding portion 17 k.

The outer diameter of the tip of the tension coil spring 16, which is one end of the tension coil spring 16, is smaller than the outer diameter of the rear end of the tension coil spring 16, which is the other end of the tension coil spring 16. That is, the outer diameter of one end of the tension coil spring 16 disposed on the reflector 13 side is smaller than the outer diameter of the other end of the tension coil spring 16 disposed on the stator 14 side. The outer diameter of the tension coil spring 16 becomes gradually larger toward the rear side.

The tip end portion of the tension coil spring 16 is disposed in the recess 11e of the holder 11. The front end portion of the tension coil spring 16 is fixed to the rear surface side of the holder 11 by an adhesive filled in the recess 11e. The rear end portion of the tension coil spring 16 is disposed in the recess 17h of the frame 17. The rear end of the tension coil spring 16 is fixed to the front surface side of the rear surface portion 17c by an adhesive filled in the recess 17h.

The tension coil spring 16 biases the reflecting portion 13 with respect to the fixed body 14 in a direction in which the contact portion 12b contacts the distal end portion of the shaft member 18. That is, the tension coil spring 16 biases the reflection unit 13 with respect to the fixed body 14 in the direction in which the contact portion 12b contacts the bead 23. Specifically, the tension coil spring 16 biases the reflection unit 13 to the rear side. The rear surface of the contact portion 12b formed in a concave curved surface shape is brought into contact with the bead 23 at a predetermined contact pressure. In the present embodiment, when the optical unit 1 is assembled, the front end portion of the tension coil spring 16 is fixed to the rear surface side of the holder 11 to which the fixing plate 12 is fixed, the rear end portion of the tension coil spring 16 is fixed to the front surface side of the rear surface portion 17c, and then the shaft member 18 is pushed into the shaft holding hole 17g from the rear side of the rear surface portion 17c and moved forward, thereby generating the biasing force of the tension coil spring 16.

In the present embodiment, a stopper (not shown) for restricting the forward movement of the reflection unit 13 is fixed or formed on the front end side of the inner side surface in the left-right direction of the side surface portion 17a of the frame 17, and the movement of the reflection unit 13 toward the front side is restricted by the contact of the holder 11 with the stopper. A gap is formed between the stopper and a portion of the holder 11 that contacts the stopper in the front-rear direction, the gap being narrower than the depth (depth in the front-rear direction) of the arrangement recess 21. Therefore, in the present embodiment, even if the reflecting portion 13 is moved forward relative to the fixed body 14 by, for example, applying an impact to the optical unit 1, the beads 23 do not move to the rear end of the placement recess 21. That is, even if an impact is applied to the optical unit 1, the reflecting portion 13 moves forward relative to the fixed body 14, and the shaft member 18 does not come off from the arrangement recess 21.

The drive mechanism 15 includes a first drive mechanism 25 and a second drive mechanism 26, the first drive mechanism 25 rotates the reflection unit 13 in the axial direction of the vertical rotation with respect to the fixed body 14, and the second drive mechanism 26 rotates the reflection unit 13 in the axial direction of the horizontal rotation with respect to the fixed body 14. In the present embodiment, the distal end portion of the shaft member 18 with which the contact portion 12b contacts serves as a fulcrum at which the reflecting portion 13 rotates with respect to the fixed body 14. That is, the bead 23 serves as a fulcrum for the rotation of the reflecting portion 13 with respect to the fixed body 14. The center of the bead 23 is the center of rotation of the reflector 13 with respect to the fixed body 14. That is, the center of curvature of the tip end portion of the shaft member 18 formed in a hemispherical shape becomes the center of rotation of the reflecting portion 13 with respect to the fixed body 14.

The first drive mechanism 25 includes: a drive magnet 27 and a drive coil 28 which are arranged to face each other in the left-right direction; and a magnetic sensor 29 for detecting the amount of rotation of the reflecting portion 13 relative to the fixed body 14 in the rotational direction in which the vertical direction is the axial direction of rotation. The second drive mechanism 26 includes: a driving magnet 31 and a driving coil 32 which are disposed to face each other in the vertical direction; and a magnetic sensor 33 for detecting the amount of rotation of the reflection unit 13 relative to the fixed body 14 in the rotation direction in which the rotation axis direction is the left-right direction. The driving magnet 27 of the present embodiment is a first driving magnet, the driving coil 28 is a first driving coil, and the magnetic sensor 29 is a first magnetic sensor. The driving magnet 31 of the present embodiment is a second driving magnet, the driving coil 32 is a second driving coil, and the magnetic sensor 33 is a second magnetic sensor.

The driving magnet 27 is formed in a substantially rectangular flat plate shape. The driving magnets 27 are fixed to both sides of the holder 11 in the left-right direction while being disposed in the recess 11b of the holder 11. When the reflection unit 13 is not rotated with respect to the fixed body 14 and the reflection unit 13 is disposed at a predetermined origin position with respect to the fixed body 14, the thickness direction of the drive magnet 27 coincides with the left-right direction. The driving magnet 31 is formed in a rectangular flat plate shape. The drive magnet 31 is fixed to the lower side of the holder 11 in a state of being disposed in the recess 11c of the holder 11. When the reflection unit 13 is disposed at the origin position, the thickness direction of the drive magnet 31 coincides with the vertical direction.

The driving coil 28 is disposed outside the driving magnet 27 in the left-right direction, and faces the driving magnet 27 in the left-right direction. The driving coil 28 is disposed in the through hole 17e of the frame 17. The driving coil 32 is disposed below the driving magnet 31 and faces the driving magnet 31 in the vertical direction. The driving coil 32 is disposed in the through hole 17f of the frame 17. The driving coils 28 and 32 are mounted on a Flexible Printed Circuit (FPC) 34. The FPC34 is fixed to the outer side surface and the lower surface of the frame 17 in the left-right direction.

The driving magnet 27 is magnetized so that the magnetic pole of the front portion of the driving magnet 27 is different from the magnetic pole of the rear portion of the driving magnet 27. That is, the driving magnet 27 is polarized to two poles in the front-rear direction. Specifically, the center of the driving magnet 27 in the front-rear direction when the reflection unit 13 is disposed at the origin position is a polarization position (magnetization polarization line) 27a, and the driving magnet 27 is polarized into two poles with the polarization position 27a as a boundary. That is, the surface of the driving magnet 27 facing the driving coil 28 is polarized into two poles at the polarization position 27a as a boundary.

Similarly, the driving magnet 31 is magnetized so that the magnetic pole of the front portion of the driving magnet 31 and the magnetic pole of the rear portion of the driving magnet 31 are different, and the driving magnet 31 is polarized to two poles in the front-rear direction. Specifically, the center of the driving magnet 31 in the front-rear direction when the reflection unit 13 is disposed at the origin position is a polarization position (magnetization polarization line) 31a, and the driving magnet 31 is polarized into two poles with the polarization position 31a as a boundary. That is, the surface of the driving magnet 31 facing the driving coil 32 is polarized to two poles at the polarized position 31a as a boundary.

When the reflecting portion 13 is disposed at the origin position, the polarization position 27a of the driving magnet 27 is disposed at the same position as the front end portion of the shaft member 18 in the front-rear direction (see fig. 7). That is, when the reflection unit 13 is disposed at the origin position, the polarization position 27a of the drive magnet 27 is disposed at the same position as the bead 23 in the front-rear direction. In the present embodiment, when the reflection unit 13 is disposed at the origin position, the polarization position 27a of the drive magnet 27 is disposed at the same position as the center of the bead 23 (i.e., the rotation center of the reflection unit 13 with respect to the fixed body 14) in the front-rear direction.

When the reflection unit 13 is disposed at the origin position, the polarization position 31a of the driving magnet 31 is disposed at the same position as the front end of the shaft member 18 in the front-rear direction (see fig. 7). That is, when the reflection unit 13 is disposed at the origin position, the polarization position 31a of the drive magnet 31 is disposed at the same position as the beads 23 in the front-rear direction. In the present embodiment, when the reflection unit 13 is disposed at the origin position, the polarization position 31a of the drive magnet 31 is disposed on the front side of the center of the bead 23.

The magnetic sensors 29, 33 are hall sensors having hall elements. The magnetic sensor 29 is disposed on the inner peripheral side of the driving coil 28, and is disposed to face the driving magnet 27 in the left-right direction. Specifically, the magnetic sensor 29 is disposed on the inner peripheral side of one driving coil 28 of the two driving coils 28, and faces one driving magnet 27 of the two driving magnets 27 in the left-right direction. The magnetic sensor 33 is disposed on the inner peripheral side of the driving coil 32, and is disposed to face the driving magnet 31 in the vertical direction. The magnetic sensors 29, 33 are mounted on the FPC 34.

When the reflection unit 13 is disposed at the origin position, the magnetic sensor 29 faces the center of the driving magnet 27, and the center of the magnetic sensitive surface of the magnetic sensor 29 in the front-rear direction is disposed at the same position as the polarization position 27a of the driving magnet 27 in the front-rear direction. When the reflection unit 13 is disposed at the origin position, the magnetic sensor 33 faces the central portion of the driving magnet 31, and the center of the magnetic sensitive surface of the magnetic sensor 33 in the front-rear direction and the polarization position 31a of the driving magnet 31 are disposed at the same position in the front-rear direction.

(main effects of the present embodiment)

As described above, in the present embodiment, the shaft member 18 is composed of the tube 22 and the bead 23 fixed to the tip of the tube 22. Therefore, in the present embodiment, even if the shaft member 18 is made thin, the ball 23 can be positioned so that the center of the ball 23 is disposed on the axial center of the shaft member 18 by the inner peripheral side of the distal end surface of the tube 22. Therefore, in the present embodiment, even if the shaft member 18 is made thin, the center of the bead 23 can be easily arranged on the axis of the shaft member 18.

In the present embodiment, in the bead fixing step of fixing the beads 23 to the distal end of the tube 22, the beads 23 are permanently fixed to the distal end of the tube 22 in a state where air on the inner peripheral side of the tube 22 is sucked from the proximal end of the tube 22 and the beads 23 are temporarily fixed to the distal end of the tube 22, so that the shaft member 18 becomes thin, the tube 22 becomes thin, and the beads 23 become small, and as a result, even if it is difficult to handle the tube 22 and the beads 23, the fixing operation of the beads 23 can be easily performed.

In the present embodiment, the tube 22 and the bead 23 are formed of the same metal material, and the bead 23 is welded and fixed to the tube 22. Therefore, in the present embodiment, the bead 23 can be relatively easily fixed to the one end of the tube 22.

In the present embodiment, a part of the beads 23 constitutes the tip end portion of the shaft member 18 protruding toward the center side of the reflection portion 13, and the beads 23 are arranged on the center side of the reflection portion 13. In the present embodiment, the reflection portion 13 is formed with the arrangement recess 21, a part of the shaft member 18 protruding toward the center side of the reflection portion 13 is arranged in the arrangement recess 21, the contact portion 12b contacting the bead 23 is formed in the arrangement recess 21, and the bead 23 serves as a fulcrum for the rotation of the reflection portion 13 with respect to the fixed body 14. Therefore, in the present embodiment, the pivot point of reflection unit 13 with respect to fixed body 14 can be brought close to the center of gravity of reflection unit 13. Therefore, in the present embodiment, the reflecting portion 13 can be smoothly rotated with respect to the fixed body 14.

In the present embodiment, the bead 23 serves as a fulcrum for the rotation of the reflecting portion 13 with respect to the fixed body 14. Therefore, in the present embodiment, the number of components constituting the pivot of the reflecting portion 13 with respect to the fixed body 14 can be reduced. In the present embodiment, the tension coil spring 16 biases the reflecting portion 13 with respect to the fixed body 14 in the direction in which the contact portion 12b contacts the bead 23. Therefore, in the present embodiment, when the driving force of the driving mechanism 15 is not applied, the reflecting portion 13 can be returned to the predetermined origin position with respect to the fixed body 14 by the biasing force of the tension coil spring 16.

In the present embodiment, when the reflection unit 13 is not rotated with respect to the fixed body 14 and the reflection unit 13 is disposed at a predetermined origin position with respect to the fixed body 14, the polarization position 27a of the drive magnet 27 is disposed at the same position as the beads 23 in the front-rear direction. In the present embodiment, when the reflection unit 13 is disposed at the origin position, the magnetic sensor 29 faces the center portion of the driving magnet 27, and the center of the magnetosensitive surface of the magnetic sensor 29 in the front-rear direction is disposed at the same position as the polarization position 27a of the driving magnet 27 in the front-rear direction. Therefore, in the present embodiment, it is possible to suppress variation in the output signal of the magnetic sensor 29 when the reflection unit 13 is rotated from the origin position with respect to the fixed body 14 with the left-right direction as the axial direction of rotation. Therefore, in the present embodiment, the accuracy of detecting the rotation amount of the reflection unit 13 by the magnetic sensor 29 can be improved.

Similarly, in the present embodiment, when the reflection unit 13 is disposed at the origin position, the polarization position 31a of the driving magnet 31 is disposed at the same position as the beads 23 in the front-rear direction, the magnetic sensor 33 faces the center portion of the driving magnet 31, and the center of the magnetic sensitive surface of the magnetic sensor 33 in the front-rear direction is disposed at the same position as the polarization position 31a of the driving magnet 31 in the front-rear direction. Therefore, in the present embodiment, it is possible to suppress variation in the output signal of the magnetic sensor 33 when the reflecting unit 13 is rotated from the origin position with respect to the fixed body 14 with the vertical direction being the axial direction of rotation. Therefore, in the present embodiment, the accuracy of detecting the rotation amount of the reflection unit 13 by the magnetic sensor 33 can be improved.

(other embodiments)

The above embodiment is an example of a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made within a scope not changing the gist of the present invention.

In the above embodiment, the outer diameter of the tension coil spring 16 may be constant. In the above embodiment, the optical unit 1 may include a spring member other than the tension coil spring 16 instead of the tension coil spring 16. For example, the optical unit 1 may be provided with a plate spring. In this case, the plate spring includes, for example, an annular fixed portion fixed to the holder 11, an annular fixed portion fixed to the back surface portion 17c of the frame 17, and a plurality of arc-shaped spring portions connecting the two fixed portions.

The leaf spring is disposed on the outer peripheral side of the shaft member 18 so as to surround the shaft member 18. Specifically, the plate spring is disposed on the outer peripheral side of the second holding portion 17k so as to surround the second holding portion 17 k. In the case where a plate spring is provided instead of the tension coil spring 16, the optical unit 1 can be downsized in the front-rear direction. Further, in the case where a leaf spring is provided instead of the tension coil spring 16, the movement of the reflection unit 13 with respect to the fixed body 14 can be restricted in the rotational direction in which the front-rear direction is the axial direction of the rotation.

In the above embodiment, the outer diameter of the bead 23 may be larger than the outer diameter of the tube 22. In the above embodiment, the tube 22 and the bead 23 may be formed of different materials. In the above embodiment, the bead 23 may be fixed to the distal end of the tube 22 with an adhesive. In the above embodiment, the reflecting portion 13 may not include the fixed plate 12. In this case, a contact portion that contacts the distal end portion of the shaft member 18 is formed inside the holder 11.

In the above embodiment, when the reflection unit 13 is disposed at the origin position, the polarization position 27a of the drive magnet 27 may be disposed at a position shifted from the bead 23 in the front-rear direction. In the above embodiment, when the reflection unit 13 is disposed at the origin position, the polarization position 31a of the drive magnet 31 may be disposed at a position shifted from the beads 23 in the front-rear direction.

In the above embodiment, the driving mechanism 15 may include a third driving mechanism for rotating the reflecting portion 13 with respect to the fixed body 14 in the axial direction in which the front-rear direction is rotational. In this case, for example, the third drive mechanism includes a drive magnet and a drive coil that are opposed to each other in the left-right direction, and the drive magnet is magnetized so that the magnetic pole of the upper portion and the magnetic pole of the lower portion of the drive magnet have different magnetic poles. In the above embodiment, the driving mechanism 15 may not include the first driving mechanism 25 or the second driving mechanism 26.

In the above embodiment, the entire shaft member 18 may be disposed in the disposition recess 21. In the above embodiment, the shaft member 18 may be arranged such that the axial direction of the shaft member 18 (i.e., the axial direction of the tube 22) coincides with the vertical direction. In this case, for example, the axial center of the shaft member 18 coincides with the optical axis L1 of the lens 4. In the above embodiment, the optical unit 1 may include a mirror having a reflection surface formed to reflect light incident from the outside, instead of the prism 10.

In the above embodiment, the shaft member 18 is used as a support shaft for supporting the reflecting portion 13, but the shaft member 18 may be used as a support shaft for supporting a rotated body other than the reflecting portion 13. The shaft member 18 may be used for other purposes than supporting a shaft. For example, the shaft member 18 may be used as a rotating shaft of a motor. In this case, for example, the beads 23 may be fixed to both ends of the tube 22. That is, the shaft member 18 may be constituted by 1 tube 22 and two beads 23.

Description of the symbols

1. Optical unit (optical unit with shake correction function)

10. Prism (reflection parts)

10a reflective surface

12b contact part

13. Reflection part

14. Fixing body

15. Driving mechanism

16. Extension coil spring (spring component)

18. Shaft component

21. Arrangement recess

22. Pipe

23. Bead

25. First driving mechanism

26. Second driving mechanism

27. Magnet for drive (first magnet for drive)

27a polarization position (polarization position of first driving magnet)

28. Driving coil (first driving coil)

29. Magnetic sensor (first magnetic sensor)

31. Magnet for drive (second magnet for drive)

31a polarization position (polarization position of second driving magnet)

32. Driving coil (second driving coil)

33. Magnetic sensor (second magnetic sensor)

Axial direction of X-axis member

Y second direction

Z first direction.

Claims (7)

1. A shaft member is characterized by comprising:

a cylindrical tube; and

a spherical bead fixed to one end of the tube,

the outer diameter of the bead is larger than the inner diameter of the tube.

2. The shaft member according to claim 1,

the tube and the bead are formed of the same metallic material,

the beads are welded to the tube.

3. A method of manufacturing a shaft member for use in manufacturing the shaft member according to claim 1 or 2,

a bead fixing step of fixing the beads to one end of the tube,

in the bead fixing step, the beads are permanently fixed to the one end of the tube in a state where air on the inner peripheral side of the tube is sucked from the other end of the tube and the beads are temporarily fixed to the one end of the tube.

4. An optical unit with a shake correction function, comprising:

a reflection unit having a reflection member formed with a reflection surface that reflects light incident from the outside;

a fixing body that holds the reflection unit;

a drive mechanism for rotating the reflection part with respect to the fixed body; and

a spring member that urges the reflection portion,

the fixing body is provided with the shaft member according to claim 1 or 2,

the shaft member protrudes toward the center side of the reflecting portion,

a part of the beads constitutes a tip portion of the shaft member,

the beads are arranged on the center side of the reflection portion,

the reflection portion is formed with a disposition recess in which at least a part of the shaft member is disposed,

a contact portion that contacts the bead is formed in the arrangement recess,

the spring member urges the reflection portion with respect to the fixed body in a direction in which the contact portion contacts the bead,

the bead serves as a pivot of the reflecting portion with respect to the fixed body.

5. The optical unit with shake correcting function according to claim 4,

the axial direction of the shaft member is orthogonal to a first direction which is an optical axis direction of light incident on the reflection surface.

6. An optical unit with a shake correcting function according to claim 5,

the drive mechanism includes: a first drive mechanism that rotates the reflection unit relative to the fixed body in an axial direction in which the first direction is a rotation direction; and a second drive mechanism that rotates the reflection unit relative to the fixed body in an axial direction in which a second direction orthogonal to the axial direction of the shaft member and the first direction is a rotational axial direction.

7. The optical unit with shake correcting function according to claim 6,

the first drive mechanism includes: a first driving magnet and a first driving coil arranged to face each other in the second direction; and a first magnetic sensor for detecting a rotation amount of the reflecting portion with respect to the fixed body in a rotation direction in an axial direction of rotation with the first direction as an axial direction of rotation,

the second drive mechanism includes: a second driving magnet and a second driving coil arranged to face each other in the first direction; and a second magnetic sensor for detecting a rotation amount of the reflecting portion with respect to the fixed body in a rotation direction in an axial direction of rotation with the second direction as an axial direction of rotation,

the first magnetic sensor is disposed to face the first driving magnet in the second direction,

the second magnetic sensor is disposed to face the second driving magnet in the first direction,

the first and second driving magnets are polarized to two poles in the axial direction of the shaft member,

when the reflecting portion is arranged at a predetermined origin position with respect to the fixed body, at least one of the polarization position of the first driving magnet and the polarization position of the second driving magnet is arranged at the same position as the beads in the axial direction of the shaft member.

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