Lens barrel and imaging device

Abstract

In order to provide a lens barrel having good optical performance, this lens barrel comprises: a lens holding frame (30) that holds a lens; a guide shaft (22) that guides the lens holding frame in an optical axis direction; a plurality of abutting parts (311, 351) that are supported by the lens holding frame (30) and abut on the guide shaft (22); and a biasing mechanism (353) that biases the lens holding frame (30) to the guide shaft (22) such that the plurality of abutting parts (311, 351) are pressed against the guide shaft (22).

Description

[Technical field]

[0001] The present invention relates to a lens barrel and an imaging device. [Background technology]

[0002] Lens barrels are required to have good optical performance (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-168492 A Summary of the Invention

[0004] According to a first aspect, a lens barrel includes a lens holding frame that holds a lens, a guide shaft that guides the lens holding frame in an optical axis direction, a plurality of abutment portions supported by the lens holding frame and abutting against the guide shaft, and a biasing mechanism that biases the lens holding frame against the guide shaft so that the plurality of abutment portions are pressed against the guide shaft.

[0005] According to a second aspect, an imaging device includes the above-mentioned lens barrel and an imaging element.

[0006] The configurations of the embodiments described below may be appropriately improved, and at least a part of them may be replaced with other components. Furthermore, components that are not particularly limited in terms of their location may be located in any location that achieves their function, not limited to the location disclosed in the embodiments. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram showing a camera including a lens barrel and a camera body according to a first embodiment. [Diagram 2] FIG. 2A is a perspective view showing the configuration of the second fixed barrel, and FIG. 2B is a diagram showing the schematic configuration of a voice coil motor. [Diagram 3] FIG. 3(A) is a schematic perspective view of a lens holding frame, and FIG. 3(B) is a view of the lens holding frame in FIG. 3(A) as viewed from the direction of arrow A1. [Figure 4] FIG. 4 is a cross-sectional view of the vicinity of the first support portion of the lens holding frame. [Diagram 5] FIG. 5 is a cross-sectional view taken along line AA in FIG. [Figure 6] FIG. 6 is an enlarged cross-sectional view of the first support portion and its vicinity in FIG. [Figure 7] FIG. 7(A) is an exploded perspective view of the biasing mechanism, and FIG. 7(B) is a cross-sectional view of the bearing support portion. [Figure 8] FIG. 8A is a perspective view for explaining the configuration of the eccentric mechanism, FIG. 8B is a plan view of an eccentric portion provided in the eccentric mechanism, and FIG. 8C is a perspective view of a fixed portion provided in the eccentric mechanism. [Figure 9] 9(A) and 9(B) are diagrams for explaining the change in position of the central axis of the bearing relative to the lens holding frame. [Figure 10] Figures 10(A) and 10(B) are diagrams for explaining the adjustment of the position of the central axis of the third lens group in a plane perpendicular to the optical axis, and Figures 10(C) and 10(D) are diagrams for explaining the adjustment of the inclination of the central axis of the third lens group with respect to the optical axis. [Figure 11] 11(A) and 11(B) are diagrams for explaining another example of the arrangement of the first bearing, the second bearing, and the third bearing. [Figure 12] FIG. 12A is a perspective view showing a lens holding frame according to another example of the first embodiment, and FIG. 12B is a side view of the lens holding frame according to the another example of the first embodiment. [Figure 13] FIG. 13 is a cross-sectional view taken along line DD in FIG. 12(B). [Figure 14] Figure 14(A) is an oblique view showing a lens holding frame according to the second embodiment, Figure 14(B) is a cross-sectional view of the lens holding frame according to the second embodiment, and Figure 14(C) is a cross-sectional view along line CC of Figure 14(B). [Figure 15]FIG. 15(A) is a schematic perspective view of a lens holding frame in the third embodiment, and FIG. 15(B) is a cross-sectional view of the vicinity of a second support portion of the lens holding frame in the third embodiment. [Figure 16] Figures 16(A) and 16(B) are diagrams for explaining the positional relationship between a first bearing and a second bearing supported by a lens holding frame, and a third bearing provided in a biasing mechanism according to a third embodiment. [Figure 17] 13A to 13C are diagrams illustrating the configuration of a mechanism for suppressing rattling between the rotation restricting bar and a fourth bearing. [Figure 18] FIG. 18(A) is a perspective view of a lens holding frame according to a modified example, and FIG. 18(B) is a view of the lens holding frame according to the modified example as viewed from the direction indicated by arrow A51 in FIG. 18(A). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] First Embodiment The lens barrel 100 according to the first embodiment will be described in detail below with reference to the drawings. Note that in each drawing, some elements may be omitted in order to make it easier to understand.

[0009] 1 is a diagram showing a camera 1 including a lens barrel 100 according to a first embodiment and a camera body 101. Note that in this embodiment, the lens barrel 100 is detachable from the camera body 101, but is not limited to this, and the lens barrel 100 and the camera body 101 may be integrated.

[0010] The camera body 101 includes an image sensor, a control unit, etc. The image sensor is composed of a photoelectric conversion element such as a CCD (Charge Coupled Device), and converts the subject image formed by the imaging optical system (lens barrel 100 attached to the camera body 101) into an electrical signal.

[0011] The control unit includes a CPU (Central Processing Unit) and controls the camera body 101 and the equipment. It generally controls the overall operation of the camera 1 relating to photography, including the focusing drive of the attached lens barrel 100.

[0012] As shown in Fig. 1, the lens barrel 100 includes a first fixed barrel 10 and a second fixed barrel 20. In this embodiment, the first fixed barrel 10 is made up of multiple parts, but it may be made up of a single part. As shown in Fig. 1, a lens mount LM that enables the lens barrel 100 to be attached to and detached from a camera body 101 is fixed to the first fixed barrel 10.

[0013] The lens barrel 100 includes first to seventh lens groups L1 to L7 arranged in sequence along a common optical axis OA. The third lens group L3 is held by a lens holding frame F3, and the other lens groups are held by a first fixed barrel 10. Each of the first to seventh lens groups L1 to L7 may be composed of a plurality of lenses. The first, second, fourth to seventh lens groups L1, L2, L4 to L7 may be held by a lens holding frame that is movable in the direction of the optical axis OA, instead of the first fixed barrel 10.

[0014] Fig. 2(A) is a perspective view showing the configuration of the second fixed barrel 20. As shown in Fig. 1 and Fig. 2(A), a guide bar 22 and a rotation restriction bar 23 are fixed to the second fixed barrel 20. The guide bar 22 guides the lens holding frame F3 in the optical axis direction. The rotation restriction bar 23 restricts the rotation of the lens holding frame F3 around the guide bar 22 as an axis.

[0015] 2(A), a voice coil motor (VCM) 50 for moving the lens holding frame F3 in the direction of the optical axis OA is provided inside the second fixed barrel 20. In this embodiment, the VCM 50 is provided at two locations inside the second fixed barrel 20, but the number of VCMs 50 is not limited to this embodiment and may be one, or three or more.

[0016] 2(B) is a diagram showing a schematic configuration of the VCM 50. The VCM 50 includes a first side yoke 501a and a second side yoke 501b each having a length in the optical axis OA direction, and a center yoke 502 having a length in the optical axis OA direction and disposed between the first side yoke 501a and the second side yoke 501b.

[0017] The VCM 50 also includes an upper yoke 503a that connects one ends in the optical axis OA direction of the first side yoke 501a, the second side yoke 501b, and the center yoke 502, and a lower yoke 503b that connects the other ends in the optical axis OA direction of the first side yoke 501a, the second side yoke 501b, and the center yoke 502. This forms a closed magnetic path.

[0018] A first magnet 504a is disposed on the side surface of the first side yoke 501a facing the center yoke 502, and a second magnet 504b is disposed on the side surface of the second side yoke 501b facing the center yoke 502. The first magnet 504a is disposed, for example, so that the center yoke 502 side is the N pole, and the second magnet 504b is also disposed so that the center yoke 502 side is the N pole. This forms a magnetic path in which magnetic flux enters the center yoke 502 from the N poles of the first magnet 504a and the second magnet 504b, passes through the upper yoke 503a and the lower yoke 503b and the first side yoke 501a and the second side yoke 501b, and returns to the S poles of the first magnet 504a and the second magnet 504b.

[0019] The VCM 50 also includes a coil 505 that penetrates the center yoke 502. There is a small gap between the inner peripheral surface of the coil 505 and the center yoke 502, allowing the coil 505 to move in the direction of the optical axis OA. The coil 505 is also configured such that the direction of magnetic flux that converges from the first side yoke 501a and the second side yoke 501b to the center yoke 502 is perpendicular to the winding direction of the coil 505.

[0020] A drive signal (electric current) is input to the coil 505. When a current flows through the coil 505, the coil 505 moves in the direction of the optical axis OA due to the magnetic force of the first magnet 504a and the second magnet 504b. More specifically, the coil 505 moves in the direction of the optical axis OA due to electromagnetic interaction between the coil 505 through which the current flows and the first magnet 504a and the second magnet 504b. By changing the direction of the current flowing through the coil 505, the movement direction of the coil 505 can be switched between the subject side and the camera body 101 side (image surface side). In addition, by changing the value of the current flowing through the coil 505, the drive force and movement speed of the coil 505 can be changed.

[0021] In this embodiment, the third lens group L3 is a focus lens group, and is moved in the optical axis OA direction by the VCM 50 to perform focus adjustment. More specifically, since the lens holding frame F3 that holds the third lens group L3 is connected to the coil 505 of the VCM 50, when the coil 505 moves in the optical axis OA direction, the third lens group L3 moves in the optical axis OA direction. Note that the third lens group L3 may be moved using a stepping motor or an ultrasonic motor instead of the VCM 50.

[0022] Next, the configuration of the lens holding frame F3 will be described. Fig. 3(A) is a schematic perspective view of the lens holding frame F3, and Fig. 3(B) is a view of the lens holding frame F3 in Fig. 3(A) as viewed from the direction of the arrow A1. Fig. 4 is a cross-sectional view of the first support portion 31 and its vicinity of the lens holding frame F3. Fig. 5 is a cross-sectional view taken along the line AA in Fig. 4, and Fig. 6 is an enlarged cross-sectional view of the first support portion 31 and its vicinity in Fig. 5. Note that in Fig. 5, hatching showing the cross-section of the first support portion 31 and the guide bar 22 is omitted, and in Fig. 6, hatching showing the cross-section of the guide bar 22 is omitted.

[0023] 3(A), the lens holding frame F3 has a cylinder portion 30 that holds the third lens group L3, and on the outer periphery of the cylinder portion 30, a first support portion 31 that supports a plurality of bearings 311 that come into contact with the guide bar 22, a second support portion 32 that supports a fourth bearing 321 (described later), and a holding portion 33 that holds a coil 505 (see FIG. 2(B)) of the VCM 50 are provided. The holding portions 33 are provided in two locations to match the number (two) of VCMs 50.

[0024] The multiple bearings 311 include a first bearing 311a and a second bearing 311b. In the first embodiment, two each of the first bearings 311a and the second bearings 311b are provided. In the following description, the first bearings 311a and the second bearings 311b will be referred to as bearings 311 unless there is a need to particularly distinguish between them.

[0025] As shown in FIG. 6, the direction in which the first bearing 311a abuts against the guide bar 22 (the direction indicated by the arrow A14) and the direction in which the second bearing 311b abuts against the guide bar 22 (the direction indicated by the arrow A15) form a predetermined angle α. In other words, the direction in which the first bearing 311a abuts against the guide bar 22 and the direction in which the second bearing 311b abuts against the guide bar 22 intersect. In other words, in the circumferential direction around the central axis AX1 of the guide bar 22, the position in which the first bearing 311a abuts against the guide bar 22 and the position in which the second bearing 311b abuts against the guide bar 22 are different. The predetermined angle α is, for example, greater than 0° and smaller than 180°. From the viewpoint of efficiently distributing the force of the compression spring 353 described later to the first bearing 311a and the second bearing 311b, it is preferable that the predetermined angle α is 30° or more and 120° or less.

[0026] 5, in the radial direction of a circle centered on the optical axis OA, the abutment point CP1 where the first bearing 311a and the guide bar 22 abut, and the abutment point CP2 where the second bearing 311b and the guide bar 22 abut are located on the inner periphery side of the central axis AX1 of the guide bar 22. In other words, as shown in FIG. 5, in a plane perpendicular to the optical axis OA and including the abutment point CP1, the straight line connecting the central axis AX1 of the guide bar 22 and the optical axis OA is longer than the straight line LN1 connecting the abutment point CP1 and the optical axis OA. In addition, in a plane perpendicular to the optical axis OA and including the abutment point CP2, the straight line connecting the central axis AX1 of the guide bar 22 and the optical axis OA is longer than the straight line LN2 connecting the abutment point CP2 and the optical axis OA. As a result, the lens barrel 100 can be made smaller in the radial direction than when the abutment points CP1 and CP2 are located on the outer periphery side of the central axis AX1 of the guide bar 22 in the radial direction of a circle centered on the optical axis OA.

[0027] In the first embodiment, a biasing mechanism 35A that biases the lens holding frame F3 against the guide bar 22 is attached to the first support portion 31 so that the first bearing 311a and the second bearing 311b are pressed against the guide bar 22.

[0028] Fig. 7(A) is a perspective view of the biasing mechanism 35A, and Fig. 7(B) is a cross-sectional view of the bearing support portion 352. The biasing mechanism 35A includes a third bearing 351 that abuts against the guide bar 22, and a bearing support portion 352 that supports the third bearing 351, as shown in Figs. 4 and 7(A).

[0029] As shown in Fig. 7(A) and Fig. 7(B), the bearing support part 352 has a hole part 352e from which the third bearing 351 protrudes, and includes a bottom part 352a extending in the optical axis OA direction, a pair of wall parts 352b provided at both ends of the short side direction of the bottom part 352a and substantially perpendicular to the bottom part 352a, and a column member 352c to which a compression spring 353 (described later) is attached. As shown in Fig. 7(B), the bearing support part 352 includes a fitting part 352d that fits with the inner peripheral surface of the inner ring of the third bearing 351. The bearing support part 352 is not fixed to the lens holding frame F3. In other words, the bearing support part 352 is movable relative to the lens holding frame F3.

[0030] 3(A), 6, and 7(A), the biasing mechanism 35A includes a fixed portion 354 having a facing portion 354a facing the bearing support portion 352 and a pair of connecting portions 354b connecting the facing portion 354a and the lens holding frame F3. As shown in FIGS. 3(A) and 3(B), the connecting portions 354b of the fixed portion 354 are connected to the lens holding frame F3 by screws 355 or the like.

[0031] Further, the biasing mechanism 35A includes a compression spring 353 that contacts the facing portion 354a and biases the third bearing 351 toward the guide bar 22. The compression spring 353 is attached to a column member 352c of the bearing support portion 352. The height of the compression spring 353 is higher than the height of the column member 352c. As a result, by disposing the bearing support portion 352 and the fixed portion 354 so that the facing portion 354a of the fixed portion 354 covers the column member 352c of the bearing support portion 352, one end of the compression spring 353 contacts the facing portion 354a and the other end contacts the bottom portion 352a of the bearing support portion 352. As a result, when the fixed portion 354 moves in the optical axis OA direction together with the lens holding frame F3, the bearing support portion 352 also moves in the optical axis OA direction together with the fixed portion 354. The column member 352c may be provided on the fixed portion 354 instead of the bearing support portion 352.

[0032] The compression spring 353 biases the bearing support portion 352 toward the guide bar 22 (in the direction indicated by the arrow A11 in FIG. 4). As a result, the third bearing 351 supported by the bearing support portion 352 is also biased toward the guide bar 22 (see the arrow A12 in FIG. 4 and FIG. 6) and pressed against the guide bar 22. The compression spring 353 also biases the fixed portion 354 in the opposite direction to the guide bar 22 (in the direction indicated by the arrow A16 in FIG. 4). As a result, the lens holding frame F3 connected to the fixed portion 354 is biased toward the guide bar 22 (see the arrow A13 in FIG. 4 and FIG. 6), and the first bearing 311a and the second bearing 311b are pressed against the guide bar 22 (see the arrows A14 and A15 in FIG. 6). As a result, rattling between the guide bar 22 and the first bearing 311a, the second bearing 311b, and the third bearing 351 is suppressed. Also, rattle between the guide bar 22 and the lens holding frame F3 is suppressed. Instead of the compression spring 353, for example, a torsion spring, a leaf spring, or an elastic body such as rubber may be used.

[0033] Next, the arrangement of the first bearing 311a, the second bearing 311b, and the third bearing 351 of the biasing mechanism 35A will be described. As shown in Fig. 6, the third bearing 351 is arranged such that, among the intersections between an imaginary line VL2 in the biasing direction (direction shown by arrow A12) of the third bearing 351 and the outer circumferential surface of the guide bar 22, an intersection IP11 farther from the third bearing 351 is located between an abutment point CP1 between the guide bar 22 and the first bearing 311a and an abutment point CP2 between the guide bar 22 and the second bearing 311b in the circumferential direction centered on the central axis AX1 of the guide bar 22. In this case, an angle β between the direction in which the first bearing 311a abuts against the guide bar 22 (direction indicated by arrow A14) and the biasing direction of the third bearing 351 (direction indicated by arrow A12) is approximately equal to an angle γ between the direction in which the second bearing 311b abuts against the guide bar 22 (direction indicated by arrow A15) and the biasing direction of the third bearing 351 (direction indicated by arrow A12). In this manner, the first bearing 311a and the second bearing 311b can be pressed against the guide bar 22 in a well-balanced manner. Note that as long as the first bearing 311a and the second bearing 311b are pressed against the guide bar 22, the angles β and γ do not have to be equal.

[0034] The configuration of the lens holding frame F3 will be further described. As shown in Fig. 4, the lens holding frame F3 has engagement portions 312a and 312b that engage with the guide bar 22. The engagement portions 312a and 312b have holes 320a and 320b, respectively, through which the guide bar 22 is inserted.

[0035] The diameter of the hole 320a is larger than the diameter of the guide bar 22, and the inner peripheral surface of the hole 320a does not contact the outer peripheral surface of the guide bar 22. In other words, the lens holding frame F3 does not contact the guide bar 22. As a result, when the lens holding frame F3 moves in the optical axis OA direction, no frictional force is generated between the engagement parts 312a and 312b of the lens holding frame F3 and the guide bar 22, so that the load on the VCM 50 can be made smaller than when the lens holding frame F3 contacts the guide bar 22. In addition, since the guide bar 22 is inserted through the holes 320a and 320b of the engagement parts 312a and 312b, even if an impact is applied to the lens barrel 100, it is possible to prevent the lens holding frame F3 from coming off the guide bar 22 and colliding with the second fixed barrel 20.

[0036] Next, a configuration for supporting the first bearing 311a and the second bearing 311b will be described. In the first embodiment, the first bearing 311a and the second bearing 311b are supported by the lens holding frame F3 via an eccentric mechanism 40. The eccentric mechanism 40 is a mechanism for changing the positions of the rotation axes of the first bearing 311a and the second bearing 311b relative to the lens holding frame F3.

[0037] Fig. 8(A) is a perspective view for explaining the configuration of the eccentric mechanism 40, Fig. 8(B) is a plan view of an eccentric portion 41 included in the eccentric mechanism 40, and Fig. 8(C) is a perspective view of a fixed portion 42 included in the eccentric mechanism 40. Note that in Fig. 8(A), the biasing mechanism 35A is omitted from the illustration.

[0038] As shown in Fig. 8(A), the eccentric mechanism 40 includes an eccentric portion 41 and a fixed portion 42. As shown in Fig. 8(B), the eccentric portion 41 is substantially annular, and a center C2 of the inner circumferential surface is shifted (eccentric) with respect to a center C1 of the outer circumferential surface.

[0039] As shown in FIG. 8(C), the fixing portion 42 has a fitting portion 421 that fits with the inner peripheral surface of the inner ring of the bearing 311 and the inner peripheral surface 401 of the eccentric portion 41. By fitting the fitting portion 421 and the inner peripheral surface 401 of the eccentric portion 41, the bearing 311 is fixed to the eccentric portion 41. At this time, the central axis (rotation axis) of the bearing 311 substantially coincides with the center C2 of the inner peripheral surface of the eccentric portion 41.

[0040] As shown in FIG. 8(A), the eccentric portion 41 fits with the inner wall of the hole 315 formed in the first support portion 31. The eccentric portion 41 is disposed in the hole 315, and for example, using a screw 45 or the like, the eccentric mechanism 40 is fixed to the first support portion 31. Thereby, the bearing 311 is supported by the lens holding frame F3.

[0041] As described above, in the eccentric portion 41, since the center C2 of the inner peripheral surface 401 is eccentric with respect to the center C1 of the outer peripheral surface, when the eccentric portion 41 is rotated in the hole 315 (rotated about the center C1 of the outer peripheral surface of the eccentric portion 41), the movement locus of the center C2 of the inner peripheral surface becomes the locus T1 shown by the dotted line in FIG. 8(B).

[0042] For example, in FIG. 9(A), it is assumed that the distance between the upper end of the first support portion 31 of the lens holding frame F3 and the center C2 of the inner peripheral surface 401 of the eccentric portion 41 is d11. Here, the eccentric portion 41 is rotated 90 degrees in the hole 315 in the direction indicated by the arrow A51. In this case, as shown in FIG. 9(B), the distance between the upper end of the first support portion 31 and the center C2 of the inner peripheral surface 401 of the eccentric portion 41 becomes d12 (<d11). Since the central axis of the bearing 311 substantially coincides with the center C2 of the inner peripheral surface of the eccentric portion 41, by rotating the eccentric portion 41, the distance between the upper end of the first support portion 31 and the central axis of the bearing 311 can be changed. That is, using the eccentric mechanism 40, the position of the central axis of the bearing 311 with respect to the first support portion 31 (lens holding frame F3) can be changed.

[0043] It is possible to adjust the position of the central axis of the third lens group L3 in a plane perpendicular to the optical axis OA and the inclination of the central axis of the third lens group L3 with respect to the optical axis OA by changing the positions of the central axes of the first bearing 311a and the second bearing 311b relative to the first support portion 31. This point will be described in detail.

[0044] 10(A) and 10(B) are diagrams for explaining the adjustment (also called shift adjustment) of the position of the central axis of the third lens group L3 on a plane perpendicular to the optical axis OA. As shown in FIG. 10(A) and FIG. 10(B), the position of the central axis of the second bearing 311b is changed by rotating the eccentric part 41 so that the distance between the second bearing 311b and the upper end of the first support part 31 becomes d2 (d1>d2) from d1 for all the second bearings 311b. As a result, the lens holding frame F3 shifts to the right as shown by the arrow A21, and the central axis of the third lens group L3 also shifts to the right. In this way, the position of the central axis of the third lens group L3 can be changed on the plane perpendicular to the optical axis OA by changing the positions of the central axes of the first bearing 311a and the second bearing 311b relative to the first support part 31 by the eccentric mechanism 40.

[0045] Figs. 10(C) and 10(D) are diagrams for explaining the adjustment of the tilt of the central axis of the third lens group L3 with respect to the optical axis OA (also referred to as tilt adjustment). As shown in Fig. 10(C), assume that in the two second bearings 311b, the distance between the central axis of the second bearing 311b and the upper end of the first support portion 31 is set to d3. At this time, in the second bearing 311b on the image plane side, the distance between the central axis of the second bearing 311b and the upper end of the first support portion 31 remains d3. In the second bearing 311b on the subject side, as shown in Fig. 10(D), the position of the central axis of the second bearing 311b is changed by rotating the eccentric portion 41 so that the distance between the central axis of the second bearing 311b and the upper end of the first support portion 31 becomes d4 (d3>d4). Similarly for the first bearing 311a, the distance between the central axis of the first bearing 311a on the image plane side and the upper end of the first support portion 31 remains d3, and in the first bearing 311a on the subject side, the distance between the central axis of the first bearing 311a and the upper end of the first support portion 31 is made d4 (<d3). Thereby, as shown in Fig. 10(D), the lens holding frame F3 tilts, so that the central axis of the third lens group L3 held by the lens holding frame F3 also tilts. In this way, the tilt of the central axis of the third lens group L3 with respect to the optical axis OA can be adjusted using the eccentric mechanism 40.

[0046] Returning to Fig. 3(A), the second support portion 32 is provided with a fourth bearing 321 so as to sandwich the rotation restricting bar 23. Thereby, the rotation of the lens holding frame F3 about the guide bar 22 can be restricted. Also, compared with the case where the rotation restricting bar 23 and the second support portion 32 are in contact, the frictional resistance between them can be reduced, and the load applied to the VCM 50 can be reduced.

[0047] As described above in detail, according to the first embodiment, the lens barrel 100 includes the lens holding frame F3 that holds the third lens group L3, the guide bar 22 that guides the lens holding frame F3 in the optical axis OA direction, a plurality of bearings 311 that are supported by the lens holding frame F3 and abut against the guide bar 22, and a biasing mechanism 35A that biases the lens holding frame F3 against the guide bar 22 so that the bearings 311 are pressed against the guide bar 22. The biasing mechanism 35A presses the plurality of bearings 311 against the guide bar 22, so that rattle between the guide bar 22 and the plurality of bearings 311 can be suppressed. This suppresses rattle between the guide bar 22 and the lens holding frame F3, and the lens holding frame F3 can be guided in the optical axis OA direction without rattle. In addition, the frictional resistance between the lens holding frame F3 and the guide bar 22 when the lens holding frame F3 moves in the optical axis OA direction can be reduced.

[0048] In the first embodiment, the position where the first bearing 311a contacts the guide bar 22 is different from the position where the second bearing 311b contacts the guide bar 22 in the circumferential direction about the central axis AX1 of the guide bar 22 (see FIG. 6). This makes it possible to suppress rattling between the first bearing 311a and the second bearing 311b and the guide bar 22, and to position the lens holding frame F3 relative to the guide bar 22.

[0049] Furthermore, in the first embodiment, in the radial direction of a circle centered on the optical axis OA, abutment point CP1 where first bearing 311a and guide bar 22 come into contact and abutment point CP2 where second bearing 311b and guide bar 22 come into contact are located on the inner circumferential side of central axis AX1 of guide bar 22. This makes it possible to reduce the radial size of lens barrel 100.

[0050] Furthermore, in the first embodiment, there is no contact between the lens retaining frame F3 and the guide bar 22. When the lens retaining frame F3 is guided by the guide bar 22 and moves in the direction of the optical axis OA, it is the bearing 311 and the third bearing 351 that contact the guide bar 22. This reduces the frictional resistance between the lens retaining frame F3 and the guide bar 22, and therefore the load on the VCM 50 can be reduced.

[0051] Furthermore, in the first embodiment, the lens holding frame F3 has holes 320a, 320b through which the guide bar 22 is inserted, and the diameters of the holes 320a, 320b are larger than the diameter of the guide bar 22. This reduces the frictional resistance between the lens holding frame F3 and the guide bar 22 when the lens holding frame F3 is guided by the guide bar 22 and moves in the optical axis OA direction, thereby reducing the load on the VCM 50. Furthermore, when an impact is applied to the lens barrel 100, it is possible to prevent the lens holding frame F3 from coming off the guide bar 22 and colliding with the inner wall of the second fixed barrel 20, for example.

[0052] In the first embodiment, the lens barrel 100 includes an eccentric mechanism 40 that changes the position of the central axis of the first bearing 311a and the second bearing 311b relative to the lens holding frame F3. This makes it possible to adjust the position of the central axis of the third lens group L3 in a plane perpendicular to the optical axis OA and the inclination of the central axis of the third lens group L3 relative to the optical axis OA. Note that the eccentric mechanism 40 does not need to be provided for all of the bearings 311. The eccentric mechanism 40 may be provided for at least one of the bearings 311, and tilt adjustment or shift adjustment may be performed for the other bearings 311 by, for example, attaching a resin or metal annular member to change the outer diameter of the bearing 311.

[0053] In the first embodiment, the biasing mechanism 35A includes a third bearing 351 that contacts the guide bar 22, a fixed portion 354 that has an opposing portion 354a that faces the guide bar 22 and is fixed to the lens holding frame F3, and a compression spring 353 that contacts the opposing portion 354a and biases the third bearing 351 toward the guide bar 22. In this case, among the intersections between the imaginary line VL2 in the biasing direction of the third bearing 351 and the outer periphery of the guide bar 22, an intersection IP11 that is farther from the third bearing 351 is located between the position (CP1) where the first bearing 311a and the guide bar 22 contact and the position (CP2) where the second bearing 311b and the guide bar 22 contact in the circumferential direction about the central axis of the guide bar 22 (see FIG. 6). This makes it possible to bias the lens holding frame F3 so that the first bearing 311a and the second bearing 311b supported by the lens holding frame F3 are pressed against the guide bar 22.

[0054] In the first embodiment, the first bearing 311a and the second bearing 311b may be arranged so that the contact points CP1 and CP2 at which the first bearing 311a and the second bearing 311b contact the guide bar 22 are located on the outer periphery side of the central axis AX1 of the guide bar 22, as shown in FIG. 11(A). In this case, for example, as shown in FIG. 11(A), the third bearing 351 may be arranged between the guide bar 22 and the lens holding frame F3, and as shown in FIG. 11(B), the compression spring 353 may be arranged between the lens holding frame F3 and the bearing support portion 352, to bias the third bearing 351 toward the guide bar 22. In this case, the pillar member 352c of the bearing support portion 352 may be provided on the lens holding frame F3. The structure for supporting the first bearing 311a and the second bearing 311b is not limited to the structure shown in FIG. 11(A) and FIG. 11(B).

[0055] In the first embodiment, the number of third bearings 351 in the biasing mechanism 35A is not limited to two, and may be one, or three or more. Also, the number of compression springs 353 in the biasing mechanism 35A is not limited to two, and may be one, or three or more.

[0056] In the first embodiment, two each of the first bearings 311a and the second bearings 311b are provided, but it is sufficient that at least one each of the first bearings 311a and the second bearings 311b are provided. Also, three or more each of the first bearings 311a and the second bearings 311b may be provided. Also, the number of the first bearings 311a and the number of the second bearings 311b may be the same or different. The same applies to the second embodiment, the third embodiment, and their modifications described below.

[0057] In the first embodiment, the functions of the first bearing 311a and the second bearing 311b may be realized by one bearing. Fig. 12(A) is a perspective view showing a lens holding frame F3 according to another example of the first embodiment, and Fig. 12(B) is a side view of the lens holding frame F3 according to another example of the first embodiment. Fig. 13 is a cross-sectional view taken along line DD in Fig. 12(B). Note that in Fig. 13, the configuration of the biasing mechanism 35A other than the third bearing 351 is omitted.

[0058] 12(A) and 12(B), in the modification of the first embodiment, a fifth bearing 311c is provided as the bearing 311. Two fifth bearings 311c are provided along the optical axis OA direction. The number of fifth bearings 311c may be three or more.

[0059] The fifth bearing 311c is provided to face the third bearing 351 across the guide bar 22. As shown in Fig. 13, the fifth bearing 311c has a bearing portion 311c1 and an annular portion 311c2.

[0060] The bearing portion 311c1 is press-fitted into a bearing support portion 316 formed on the first support portion 31.

[0061] The annular portion 311c2 is an annular member. An inner peripheral surface of the annular portion 311c2 and an outer ring of the bearing portion 311c1 are fitted together.

[0062] 13, a groove G1 is formed on the outer circumferential surface of the annular portion 311c2 so as to come into contact with the guide bar 22 at two points (CP3, CP4). In this embodiment, the groove G1 is substantially V-shaped. Note that the shape of the groove G1 is not limited to a V-shape, and may be any shape that allows the guide bar 22 and the annular portion 311c2 to come into contact with each other at two points.

[0063] In Figure 13, abutment point CP3 corresponds to abutment point CP1 (see Figure 5) where the first bearing 311a and the guide bar 22 described in the first embodiment abut, and abutment point CP4 corresponds to abutment point CP2 where the second bearing 311b and the guide bar 22 described in the first embodiment abut.

[0064] In the lens holding frame F3 according to another example of the first embodiment, the number of bearings can be reduced compared to the first embodiment, and therefore the structure of the lens holding frame F3 can be simplified. Also, as shown in Fig. 13, the third bearing 351 and the fifth bearing 311c are arranged to face each other with the guide bar 22 in between, thereby making it possible to reduce the size of the lens holding frame F3.

[0065] The third bearing 351 and the fifth bearing 311c do not necessarily have to face each other. Also, the arrangement positions of the third bearing 351 and the fifth bearing 311c may be reversed from that in Fig. 13. That is, the third bearing 351 may be arranged between the lens holding frame F3 and the guide bar 22, and the fifth bearing 311c may be arranged on the outer circumferential side of the guide bar 22.

[0066] Second Embodiment In the second embodiment, instead of the biasing mechanism 35A, a guide bar 22 made of a magnet or a ferromagnetic material and a magnet 356 that is attracted to the guide bar 22 are used to bias the lens holding frame F3 against the guide bar 22 so that the first bearing 311a and the second bearing 311b are pressed against the guide bar 22.

[0067] Figure 14(A) is an oblique view showing a lens holding frame F3 according to the second embodiment, Figure 14(B) is a cross-sectional view of the lens holding frame F3 according to the second embodiment, and Figure 14(C) is a cross-sectional view along line CC in Figure 14(B).

[0068] In the second embodiment, the guide bar 22 is made of a magnet or a ferromagnetic material. As shown in Fig. 14(A), a magnet 356 that attracts the guide bar 22 is fixed to the lens holding frame F3 at a position facing the guide bar 22. As shown in Fig. 14(C), the magnet 356 is disposed between the first bearing 311a and the second bearing 311b in the circumferential direction about the central axis AX1 of the guide bar 22.

[0069] Since guide bar 22 is fixed to second fixed barrel 20, magnet 356 is attracted to guide bar 22, and lens holding frame F3 is biased toward guide bar 22 (in the direction indicated by arrow A31 in FIG. 14(B)).

[0070] As a result, similarly to the first embodiment, the first bearing 311a and the second bearing 311b are pressed against the guide bar 22, suppressing rattle between the guide bar 22 and the first bearing 311a and the second bearing 311b. Other configurations are similar to those of the first embodiment, and detailed explanations are omitted. In the second embodiment, the biasing mechanism 35A is not required, so miniaturization is possible. Also, since the number of bearings is reduced (there is no third bearing 351 that contacts the guide bar 22), sliding noise and sliding resistance can be reduced.

[0071] In the second embodiment, the lens holding frame F3 is biased toward the guide bar 22 by making the magnet 356 attracted to the guide bar 22, which is made of a magnet or a ferromagnetic material, but this is not limited to this.

[0072] For example, the rotation restriction bar 23 may be made of a magnet, and the magnet may be arranged in the part of the second support part 32 facing the rotation restriction bar 23 so as to repel the rotation restriction bar 23, thereby biasing the lens holding frame F3 toward the guide bar 22.

[0073] Third Embodiment In the third embodiment, a biasing mechanism that biases the lens holding frame F3 against the guide bar 22 is provided in the second support portion 32.

[0074] FIG. 15(A) is a schematic perspective view of a lens holding frame F3 in the third embodiment, and FIG. 15(B) is a cross-sectional view of the vicinity of a second support portion 32 of the lens holding frame F3 in the third embodiment.

[0075] As shown in Fig. 15(A) and Fig. 15(B), the biasing mechanism 35C is provided on the second support portion 32. As shown in Fig. 15(B), the biasing mechanism 35C includes a third bearing 351, a bearing support portion 352 supporting the third bearing 351, and a compression spring 353 disposed between the second support portion 32 of the lens holding frame F3 and the bearing support portion 352. In the biasing mechanism 35C, the bearing support portion 352 does not include a column member 352c, and the compression spring 353 is disposed in a hole 323 formed in the second support portion 32, with one end in contact with the second support portion 32 and the other end in contact with the bearing support portion 352. As a result, the bearing support portion 352 is not fixed to the lens holding frame F3, but when the lens holding frame F3 moves in the optical axis OA direction, the bearing support portion 352 also moves in the optical axis OA direction, as in the first embodiment.

[0076] As shown in FIG. 15(B), a compression spring 353 is disposed between the second support portion 32 and the bearing support portion 352. The compression spring 353 biases the third bearing 351 toward the rotation restriction bar 23 via the bearing support portion 352. More specifically, the compression spring 353 biases the bearing support portion 352 toward the rotation restriction bar 23 (in the direction indicated by the arrow A41 in FIG. 15(B)). As a result, the third bearing 351 is also biased toward the rotation restriction bar 23 (see the arrow A42 in FIG. 15(B)) and pressed against the rotation restriction bar 23. As a result, the lens holding frame F3 is biased toward the guide bar 22 (see the arrow A43 in FIG. 15(B)). As a result, as described in the first embodiment, the first bearing 311a and the second bearing 311b are pressed against the guide bar 22, suppressing rattling between the guide bar 22 and the first bearing 311a and the second bearing 311b. Note that instead of the compression spring 353, for example, a torsion spring, a leaf spring, or an elastic body such as rubber may be used.

[0077] Next, the arrangement of the first bearing 311a, the second bearing 311b, and the third bearing 351 will be described. Fig. 16(A) is a diagram for explaining the arrangement of the first bearing 311a, the second bearing 311b, and the third bearing 351, and Fig. 16(B) is a cross-sectional view near the guide bar 22. The cross-section of Fig. 16(B) corresponds to the cross-section of line AA in Fig. 4. For ease of viewing, hatching representing the cross-section of the guide bar 22 and the first support part 31 has been omitted.

[0078] As shown in Fig. 16(A), an imaginary line VL1 in a direction D5 opposite to the biasing direction D4 of the third bearing 351 intersects with the guide bar 22. In addition, in the circumferential direction around the central axis AX1 of the guide bar 22, among the intersections between the imaginary line VL1 and the outer periphery of the guide bar 22, an intersection point IP1 closer to the third bearing 351 is located between a position (CP1) where the first bearing 311a and the guide bar 22 contact each other and a position (CP2) where the second bearing 311b and the guide bar 22 contact each other. In this case, as shown in Fig. 16(B), it is preferable that an angle δ formed between the direction D5 and the direction D1 in which the first bearing 311a and the guide bar 22 contact each other and an angle ε formed between the direction D5 and the direction D2 in which the second bearing 311b and the guide bar 22 contact each other are substantially equal.

[0079] In the third embodiment, in addition to the biasing mechanism 35C, the second support portion 32 is provided with a rattle suppression mechanism 36 that suppresses rattle between the rotation restricting bar 23 and the fourth bearing 321. Fig. 17 is a diagram for explaining the configuration of the rattle suppression mechanism 36.

[0080] As shown in FIG. 17, the rattle suppression mechanism 36 is fixed to the second support portion 32 and includes a support portion 361 that supports one side of the fourth bearing 321, and a compression spring 362 that urges the other side of the fourth bearing 321 toward the guide bar 22.

[0081] The other side of the fourth bearing 321 is supported by a protrusion 322 that protrudes from the second support part 32 to the outer periphery, and the protrusion 322 is flexible. One end of a compression spring 362 is connected to the support part 361, and the other end is connected to the protrusion 322. This causes the protrusion 322 to bend toward the guide bar 22, and as a result, one side of the fourth bearing 321 is pressed against the rotation restriction bar 23 (in the direction shown by the arrow A35 in FIG. 17). This makes it possible to suppress rattling between the rotation restriction bar 23 and the fourth bearing 321.

[0082] The rattle suppression mechanism 36 may be applied to the first and second embodiments. In the third embodiment, the rattle suppression mechanism 36 may not be provided on the second support portion 32, and the guide bar 22 may be sandwiched without biasing the fourth bearing 321, as in the first and second embodiments.

[0083] (Modification) In the first to third embodiments described above, the first bearing 311a and the second bearing 311b are arranged alternately along the direction of the optical axis OA, but the arrangement of the first bearing 311a and the second bearing 311b is not limited to this.

[0084] FIG. 18(A) is a perspective view of a lens holding frame F3 according to a modified example, and FIG. 18(B) is a view of the lens holding frame F3 in FIG. 18(A) as viewed from the direction indicated by arrow A51.

[0085] As shown in FIG. 18(B), in the modified example, the first bearing 311a and the second bearing 311b are disposed at approximately the same position in the direction of the optical axis OA.

[0086] In the modified example, the first bearing 311a and the second bearing 311b are press-fitted into the bearing support portion 316 formed in the first support portion 31. In this way, the eccentric mechanism 40 does not need to be provided. In this case, the positions of the central axes of the first bearing 311a and the second bearing 311b cannot be changed with respect to the lens holding frame F3. However, by attaching an annular member made of resin or metal to the outer periphery of the first bearing 311a and the second bearing 311b to change the outer diameter of the first bearing 311a and the second bearing 311b, the shift adjustment and tilt adjustment of the lens holding frame F3 can be performed as in the first embodiment. Also, the tilt adjustment may be performed by tilting the guide bar.

[0087] Other configurations are the same as those in the first embodiment, and therefore detailed description will be omitted. In the modified example, instead of the biasing mechanism 35A, the guide bar 22 and the magnet 356 made of a ferromagnetic material as in the second embodiment may be used, or the biasing mechanism 35C of the third embodiment may be used.

[0088] In the first to third embodiments and their modified examples, protrusions that come into contact with the guide bar 22 may be used in place of the first bearing 311a, the second bearing 311b, the third bearing 351, and the fifth bearing 311c.

[0089] In the above embodiment and its modified examples, the second fixed barrel 20 that houses the lens holding frame F3 may be a movable barrel that is capable of moving linearly in the direction of the optical axis OA. In the above embodiment and its modified examples, the lens barrel 100 may be a fixed focal length lens or a zoom lens.

[0090] The above-described embodiment is a preferred example, but is not limited thereto, and various modifications are possible without departing from the scope of the present invention, and any combination of components may be used. [Explanation of symbols]

[0091] 1 Camera 22 Guide bar 23 Rotation control bar 100 Lens barrel 311 Bearing 311a No. 1 bearing 311b 2nd bearing 321 4th bearing 351 3rd bearing 352 Bearing support 353 Compression Spring 354 Fixed part 354a Opposite part F3 lens holder L3: Third lens group

Claims

1. a lens holding frame for holding a lens; a guide shaft that guides the lens holding frame in an optical axis direction; a plurality of contact portions supported by the lens holding frame and contacting the guide shaft; a first biasing mechanism having at least two bearings arranged along the guide shaft and in contact with the guide shaft, the first biasing mechanism biasing the at least two bearings toward the guide shaft in a direction perpendicular to the optical axis, thereby pressing the plurality of abutment portions against the guide shaft; A lens barrel comprising:

2. The plurality of abutment portions include a first bearing and a second bearing, a direction in which the first bearing abuts against the guide shaft and a direction in which the second bearing abuts against the guide shaft form a predetermined angle; The lens barrel according to claim 1 .

3. The plurality of abutment portions include a first bearing and a second bearing, a direction in which the first bearing abuts against the guide shaft and a direction in which the second bearing abuts against the guide shaft intersect with each other; The lens barrel according to claim 1 .

4. The plurality of abutment portions include a first bearing and a second bearing, In a circumferential direction around a central axis of the guide shaft, a position where the first bearing and the guide shaft contact each other is different from a position where the second bearing and the guide shaft contact each other. The lens barrel according to claim 1 .

5. Two first bearings are arranged along the guide shaft. The lens barrel according to any one of claims 2 to 4.

6. Two second bearings are arranged along the guide shaft. The lens barrel according to any one of claims 2 to 5.

7. An angle between a direction in which the first bearing abuts against the guide shaft and a direction in which the at least two bearings abut against the guide shaft is substantially equal to an angle between a direction in which the second bearing abuts against the guide shaft and a direction in which the at least two bearings abut against the guide shaft. The lens barrel according to any one of claims 2 to 6.

8. The first biasing mechanism includes: A support portion that supports the at least two bearings; A fixing portion fixed to the lens holding frame; A biasing portion configured as a compression spring and disposed between the support portion and the fixed portion; Equipped with The lens barrel according to any one of claims 1 to 7.

9. The fixed portion has an opposing portion opposing the at least two bearings and a connecting portion connected to the lens holding frame, The opposing portion and the connecting portion are disposed along the guide shaft, the at least two bearings and the biasing portion are arranged on a straight line parallel to an optical axis, the biasing portion contacts the opposing portion and biases the at least two bearings toward the guide shaft; The lens barrel according to claim 8.

10. Among the intersections between the imaginary lines of the biasing directions of the at least two bearings and the outer periphery of the guide shaft, an intersection farther from the at least two bearings is located between a position where one of the plurality of abutment portions contacts the guide shaft and a position where another of the plurality of abutment portions contacts the guide shaft in a circumferential direction about a central axis of the guide shaft. The lens barrel according to any one of claims 1 to 9.

11. a regulating shaft that regulates rotation of the lens holding frame about the guide shaft; a third bearing that abuts against the regulating shaft; a second biasing mechanism having a biasing portion that contacts the lens holding frame and biases the third bearing toward the restriction shaft; The lens barrel according to claim 1 , further comprising:

12. At least one of the guide shaft or the regulating shaft is made of a magnet or a ferromagnetic material; The lens holding frame is disposed to face the guide shaft and includes a magnet that is attracted to the guide shaft. The lens barrel according to claim 11.

13. The at least two bearings are arranged in pairs along the guide shaft. The lens barrel according to any one of claims 1 to 12.

14. In each plane perpendicular to the optical axis and including the abutment points where the abutment portions and the guide shaft abut, a straight line connecting the central axis of the guide shaft and the optical axis is longer than a straight line connecting the abutment points and the optical axis. The lens barrel according to any one of claims 1 to 13.

15. In a radial direction of a circle centered on the optical axis, abutment points at which the plurality of abutment portions and the guide shaft abut are located on an inner peripheral side with respect to a central axis of the guide shaft. The lens barrel according to any one of claims 1 to 14.

16. The lens holding frame and the guide shaft are not in contact with each other. The lens barrel according to any one of claims 1 to 15.

17. the lens holding frame has a hole through which the guide shaft is inserted, The diameter of the hole is larger than the diameter of the guide shaft. The lens barrel according to any one of claims 1 to 16.

18. an eccentric mechanism that changes a position of a central axis of at least one of the plurality of contact portions with respect to the lens holding frame; The lens barrel according to any one of claims 1 to 17.

19. The lens holding frame has a first engagement portion having a first hole through which the guide shaft is inserted and engaging with the guide shaft, and a second engagement portion having a second hole through which the guide shaft is inserted and engaging with the guide shaft, the first biasing mechanism is disposed between the first engagement portion and the second engagement portion in the optical axis direction; The lens barrel according to any one of claims 1 to 18.

20. The lens barrel according to any one of claims 1 to 19, An imaging element; An imaging device comprising:

Images