Lens barrel, interchangeable lens, and imaging apparatus

Abstract

To provide a lens barrel that is small-sized and has good optical performance.SOLUTION: A lens barrel has: lenses; a barrel that holds the lenses and is movable in a direction along an optical axis; a cylindrical base member that is located on an outer periphery of the barrel; a guide bar that is fixed to the base member at at least one end; a holding member that holds the other end of the guide bar; and a guide unit that is fixed to the barrel with a fixing part and has urging means urging a first rotation element and a second rotation element against the guide bar. On a flat surface orthogonal to the optical axis, the distances to the center of the optical axis from a first contact that is a point at which the guide bar and the first rotation element are in contact with each other, a second contact at which the guide bar and the second rotation element are in contact with each other, and the urging means, are longer than the distance from the center of the guide bar to the center of the optical axis. When seen from both sides in a direction along the optical axis, the guide unit overlaps the base member. When seen along the optical axis, the urging means is arranged between the first contact and the second contact.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] In a lens device used in a video camera, a digital camera, etc., there is known a lens device that guides a lens and a lens barrel that holds the lens in the optical axis direction along a guide member that extends in the optical axis direction. In such a configuration, when the lens device has a large mass, it is necessary to maintain a stable state against changes in the influence of gravity caused by changes in the attitude of the lens device. As a result, the driving load when moving the lens becomes large, so a lens device having a lens barrel that uses a ball bearing to reduce the driving load is known.

[0003] For example, Patent Document 1 discloses a structure in which a unit with a pair of ball bearings arranged in a V shape is screwed to the lens barrel from the optical axis direction and biased against the guide bar by a magnet provided in the barrel, while Patent Document 2 discloses a structure in which two pairs of ball bearings arranged in a V shape are further biased against the lens barrel by using a ball bearing for biasing.

[0004] In order to prevent the lens from tilting during assembly and to improve optical performance, it is necessary to ensure the strength of the base member that holds the guide bar. To ensure the strength of the base member within a limited size, it is effective to make the diameter of the opening as small as possible. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-135428 [Patent Document 2] International Publication No. 2023 / 48001 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the conventional technology disclosed in the above-mentioned Patent Document 1, the movable group had to be assembled from the front, and an opening the size of the movable group was required. In the conventional technology disclosed in Patent Document 2, the ball bearing for biasing is rear-assembled to the movable group and rear-assembled to the base, thereby making the opening of the base smaller and ensuring strength. However, it was necessary to provide an opening in either the front or rear of the base member to pass through the two pairs of ball bearings arranged in a V shape.

[0007] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a lens barrel that is small in size and has good optical performance. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, a lens barrel as one aspect of the present invention comprises a lens, a barrel that holds the lens and is movable in a direction along an optical axis, a cylindrical base member located on the outer periphery of the barrel, a guide bar having at least one end fixed to the base member, a holding member that holds the other end of the guide bar, and a guide unit fixed to the barrel by a fixing portion and having a biasing means that biases a first rotating element and a second rotating element to the guide bar, wherein in a plane perpendicular to the optical axis, a first contact point where the guide bar and the first rotating element are in contact, a second contact point where the guide bar and the second rotating element are in contact, and a distance from the biasing means to the center of the optical axis is longer than a distance from the center of the guide bar to the center of the optical axis, and when viewed from both sides in the direction along the optical axis, the guide unit overlaps with the base member, and when viewed along the optical axis, the biasing means is positioned between the first contact point and the second contact point. Effect of the Invention

[0009] According to the present invention, it is possible to provide a lens barrel that is small in size and has good optical performance. [Brief description of the drawings]

[0010] [Figure 1] 1 is a diagram illustrating the configuration of a lens barrel and a camera that constitute an imaging apparatus according to an embodiment. [Diagram 2] FIG. 2 is a unit diagram illustrating elements that configure a fourth group unit in the embodiment. [Diagram 3] FIG. 2 is a configuration diagram for explaining a configuration for supporting a fourth group unit in an embodiment so that the fourth group unit can be controlled to be driven in the optical axis direction. [Figure 4] 4A and 4B are external views for explaining the configuration of a guide unit according to the embodiment. [Diagram 5] FIG. 1 is a cross-sectional view illustrating contact points between a main magnet and a ball bearing relative to a main guide bar when the lens barrel according to the embodiment is viewed along the optical axis from the object side. [Figure 6] FIG. 4 is a cross-sectional view illustrating elements that configure the guide according to the embodiment. [Figure 7] FIG. 4 is a cross-sectional view illustrating elements that configure position detection of the fourth group unit in the embodiment. [Figure 8] FIG. 2 is an exploded perspective view of the lens barrel according to the embodiment. [Figure 9] 13 is an external view illustrating a receiving surface of the lens barrel unit when the guide unit base is assembled in the embodiment. FIG. [Figure 10] FIG. 4 is a cross-sectional view illustrating the position of a hole in the lens barrel in the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In each drawing, the same members or elements are given the same reference numerals, and duplicated descriptions will be omitted or simplified.

[0012] <Example 1> FIG. 1 is a diagram showing the configuration of a lens barrel 10 (lens device) and a camera 20 which constitute an imaging device 1 according to this embodiment.

[0013] The camera 20 has an imaging element 30 and is configured to be able to capture an image formed through the lens barrel 10. The lens barrel 10 is provided with a mount (mount portion) 40, and in this embodiment, the lens barrel 10 and the mount 40 function as an interchangeable lens. The mount 40 is configured to be attachable to a mount (not shown) of the camera 20, and by attaching it to the mount of the camera 20, it can be communicatively connected to the camera 20. Then, by attaching the mount 40 to the mount of the camera 20, the lens barrel 10 can be fixed to the camera 20.

[0014] Lens barrel 10 has lens 101, lens 201, lens 301, lens 401, and lens 501 as optical elements, in that order from the subject side. Lens 101 is held by a first group barrel, lens 201 by a second group barrel, lens 301 by a third group barrel, lens 401 by a fourth group barrel, and lens 401 by a fifth group barrel. Lens barrel 10 has a first group unit 100 having lens 101 and a first group barrel. Lens barrel 10 also has a second group unit 200 having lens 201 and a second group barrel. Lens barrel 10 also has a third group unit 300 having lens 301 and a third group barrel. Lens barrel 10 also has a fourth group unit 400 having lens 401 and a fourth group barrel. Lens barrel 10 also has a fifth group unit 500 having lens 501 and a fifth group barrel. Moreover, each of these units is held by a base (base member) 601. The base 601 is a cylindrical member configured to be positioned on the outer periphery of each of these units.

[0015] Second group unit 200 and fourth group unit 400 are focus groups, and are each guided by a guide bar. Furthermore, second group unit 200 and fourth group unit 400 are each configured to be drive-controllable by an actuator. Then, by rotating operation ring 50, they move along optical axis 70. This changes the positional relationship of each in the direction along optical axis 70, and changes the focus position of lens barrel 10. Each actuator is drive-controlled by main CPU 60.

[0016] The actuator of second group unit 200 is an actuator using a vibrator, and the detailed configuration is known and therefore will be omitted. The actuator of fourth group unit 400 is a voice coil motor (VCM), and the details will be described later.

[0017] The main CPU 60 is a central processing unit, and controls the imaging device 1 by executing a control program stored in a memory (not shown). That is, it comprehensively controls each component of the imaging device 1. The main CPU 60 controls the imaging device 1 by communicating with a main CPU (not shown) on the camera 20 side. That is, the main CPU 60 controls the imaging device 1 by receiving a predetermined control signal from the main CPU on the camera 20 side and executing a control program stored in a memory (not shown).

[0018] Fig. 2 is an example of a unit diagram illustrating elements that configure fourth group unit 400. Fig. 3 is an example of a configuration diagram illustrating a configuration for supporting fourth group unit 400 so that it can be driven and controlled in the direction of optical axis 70.

[0019] Lens 401 held in fourth group unit 400 is fixed to lens barrel 402. Lens barrel 402 is held in lens barrel base 403 so as to be adjustably moved by adjustment rollers 405a, 405b, 405c, 405d, 405e, and 405f, constituting lens barrel unit 404. Note that the adjustment structure using these adjustment rollers is well known, and therefore will not be described in detail.

[0020] Guide unit 406 is fixed to barrel unit 404 to enable guiding by main guide bar 602 fixed to base 601. The configuration of guide unit 406 will be described later, but with this configuration it rolls on ball bearings as rotating elements relative to main guide bar 602, and the inclination component and guide direction of barrel unit 404 relative to base 601 are determined. At this time, a sub-magnet (not shown) fixed to sub-yoke 423 biases sub-guide bar 603, and the ball bearings and sub-guide bar 603 are in contact.

[0021] In the lens barrel unit 404, a ball bearing 419 for guiding the sub-guide bar 603 fixed to the base 601 is rotatably held by a shaft screw 420. With this configuration, the eccentricity component of the lens 401 with respect to the optical axis 70 of the lens barrel 10 is determined.

[0022] One end of each of main guide bar 602 and sub guide bar 603 is held by base (base member) 601, and the other end is held by the fifth group barrel (holding member) in fifth group unit 500. In this manner, one of main guide bar 602 and sub guide bar 603 of the base member is fixed to base 601, and the other is fixed by the fifth group barrel. In this embodiment, main guide bar 602 is made of a soft magnetic material such as SUS430.

[0023] The lens barrel unit 404 holds coils 424a and 424b which constitute an actuator for driving the lens barrel unit 404. The lens barrel unit 404 also holds a flexible cable 425 for passing a current through the coils 424a and 424b. The flexible cable 425 forms a U-turn between the base 601 and the lens barrel base 403, and the lens barrel base 403 is movable in the guide direction relative to the base 601.

[0024] Next, the configuration of the magnetic circuit of the actuator will be described. Inside the coil 424a, a center yoke 606a is arranged with a clearance and is fixed to the base 601. At the front and rear of the center yoke 606a in the optical axis direction, a front base yoke 605a and a rear base yoke 609a are attracted by magnets described later and are in contact with the center yoke 606a. The front base yoke 605a and the rear base yoke 609a have flat parts at approximately the same distance on both sides of the optical axis 70 in the arc direction. The flat parts are approximately parallel to each other, and have back yokes 608a and 608b that are attracted and held by VCM magnets 607a (magnets) and VCM magnets 607b (magnets) described later. In this way, each yoke is held by being attracted by magnets such as the VCM magnets 607a and VCM magnets 607b. The VCM magnets 607a and 607b are fixed to the coil sides of the respective back yokes. In this embodiment, the magnetic circuit is configured as described above.

[0025] Although details are omitted, a similar configuration is adopted for coil 424b, and it is possible to drive lens barrel unit 404 in the guided direction by passing a current through each coil. The detailed principles and control are publicly known techniques, so explanations are omitted.

[0026] 4 is an external view for explaining the configuration of guide unit 406. Guide unit 406 is composed of guide unit base 407 fixed to lens barrel base 403. Main guide bar 602 is fixed to guide unit base 407. Furthermore, four ball bearings for rolling and guiding are fixed as a ball bearing unit by shaft screws and nuts. That is, guide unit base 407 of this embodiment is configured to have main guide bar 602 and ball bearing units 411a, 411b, 411c, and 411d.

[0027] Here, ball bearing (first rotating element) 408a is fixed to guide unit base 407 by axial screw 409a and nut 410a. This constitutes ball bearing unit 411a. That is, ball bearing unit 411a has ball bearing 408a, axial screw 409a, and nut 410a. Moreover, ball bearing (second rotating element) 408b is fixed to guide unit base 407 by axial screw 409b and nut 410b. This constitutes ball bearing unit 411b. That is, ball bearing unit 411b has ball bearing 408b, axial screw 409b, and nut 410b. Moreover, ball bearing (third rotating element) 408c is fixed to guide unit base 407 by axial screw 409c and nut 410c. This constitutes ball bearing unit 411c. That is, ball bearing unit 411c has ball bearing 408c, axial screw 409c, and nut 410c. Moreover, ball bearing (fourth rotating element) 408d is fixed to guide unit base 407 by axial screw 409d and nut 410d. This constitutes ball bearing unit 411d. That is, ball bearing unit 411d has ball bearing 408d, axial screw 409d, and nut 410d. Thus, in this embodiment, the four ball bearings are held in the state of a ball bearing unit.

[0028] Ball bearing unit 411a is held (fixed) on the subject side at a position that substantially overlaps ball bearing unit 411c when viewed in the direction along optical axis 70. Ball bearing unit 411b is disposed (fixed) on the subject side at a position that substantially overlaps ball bearing unit 411d when viewed in the direction along optical axis 70. Ball bearing unit 411a is disposed adjacent to ball bearing unit 411b in the circumferential direction with main guide bar 602 in between.

[0029] Ball bearing unit 411c is held (fixed) on the image surface side at a position that substantially overlaps with ball bearing unit 411a when viewed from the direction of optical axis 70. Ball bearing unit 411d is held (fixed) on the image surface side at a position that substantially overlaps with ball bearing unit 411b when viewed from the direction along optical axis 70. Ball bearing unit 411c is disposed at a position adjacent to ball bearing unit 411d in the circumferential direction with main guide bar 602 in between.

[0030] Guide unit base 407 further has main magnet 413 as a biasing means for biasing main guide bar 602. By making main guide bar 602 out of a soft magnetic material such as SUS430, magnetic attraction occurs, and the main guide bar 602 is attracted to the main guide bar 602, generating a biasing force against main guide bar 602. In other words, this biasing force causes each of the ball bearings described above to come into contact with and roll against main guide bar 602.

[0031] Fig. 5 is a cross-sectional view illustrating the contact points of main magnet 413 and ball bearings with respect to main guide bar 602 when the lens barrel is viewed along the optical axis from the object side. The positional relationship between ball bearings 408a and 408b fixed to guide unit base 407 (not shown) and main guide bar 602 (first contact point, second contact point), and main magnet 413 in the cross section shown in Fig. 5 will be described.

[0032] A distance 701 exists between a main guide bar center 700 of main guide bar 602 and optical axis 70 of lens barrel 10 on a plane perpendicular to optical axis 70. A distance 703 exists between a first contact point 702, which is a contact point between ball bearing 408a and main guide bar 602, and the optical axis 70 on a plane perpendicular to optical axis 70. In this case, distance 703, which is the distance on the plane perpendicular to optical axis 70, is longer than distance 701. Moreover, first contact point 702 is on the right side (right side in FIG. 5) of a line connecting main guide bar center 700 and optical axis 70 when viewed from the object side.

[0033] Furthermore, there is a distance 705 on a plane perpendicular to the optical axis between second tangent point 704, which is the contact point between ball bearing 408b and main guide bar 602, and optical axis 70. In this case, distance 705, which is the distance on the plane perpendicular to optical axis 70, is longer than distance 701. Moreover, second tangent point 704 is on the left side of the line connecting main guide bar center 700 and optical axis 70 when viewed from the object side.

[0034] In other words, ball bearings 408a and 408b each contact main guide bar 602 on either side of the line connecting main guide bar center 700 and optical axis 70, and thus have contact points (first contact point, second contact point) on the outside of main guide bar 602.

[0035] The main magnet 413 and the optical axis 70 have a distance 706 on a plane perpendicular to the optical axis 70. In this case, the distance 706 is longer than the distance 701, and the main magnet 413 is on a line connecting the main guide bar center 700 and the optical axis 70 when viewed from the object side. That is, when viewed from the direction of the optical axis 70, the main magnet 413 is located between the ball bearing 408a and the ball bearing 408b. In other words, when viewed from the direction along the optical axis 70, the main magnet 413 functioning as a biasing means is located between the first contact point and the second contact point. Then, the ball bearing 408a and the ball bearing 408b are magnetically attracted to the main guide bar 602, and come into contact with the main guide bar 602, respectively, thereby forming the first contact point 702 and the second contact point 704, and the positions are uniquely determined.

[0036] Thus, in a plane perpendicular to the optical axis 70, the distances from the first contact point, the second contact point, and the main magnet 413 to the center of the optical axis (distances 703, 705, 706) are longer than the distance from the main guide bar center 700 to the center of the optical axis (distance 701).

[0037] When viewed from the direction along the optical axis 70, the ball bearing 408c overlaps with the ball bearing 408a, and the ball bearing 408d overlaps with the ball bearing 408b. The ball bearings 408a and 408c, and the ball bearings 408c and 408d are configured to be spaced apart in the direction of the optical axis 70, and each ball bearing is fixed to the guide unit base 407.

[0038] The ball bearings 408c and 408d have the same configuration as the ball bearings 408a and 408b described above. That is, the ball bearings 408c and 408d contact the main guide bar 602 across the line connecting the main guide bar center 700 and the optical axis 70, and have contact points on the outside of the main guide bar 602. As in the above, a third contact point (not shown) which is a contact point between the ball bearing 408c and the main guide bar 602 and the optical axis 70 has a distance similar to the distance 703 on a plane perpendicular to the optical axis 70. Furthermore, a fourth contact point (not shown) which is a contact point between the ball bearing 408d and the main guide bar 602 and the optical axis 70 has a distance similar to the distance 705 on a plane perpendicular to the optical axis 70.

[0039] When viewed from the direction along optical axis 70, main magnet 413 is located between ball bearing 408c and ball bearing 408d. In other words, when viewed from the direction along optical axis 70, main magnet 413 functioning as a biasing means is disposed between the third contact point and the fourth contact point. Ball bearing 408a and ball bearing 408b are magnetically attracted to main guide bar 602, and come into contact with main guide bar 602, thereby constituting the third contact point and the fourth contact point, and the positions are uniquely determined.

[0040] Thus, in a plane perpendicular to the optical axis 70, the distances from the third contact point, the fourth contact point, and the main magnet 413 to the center of the optical axis are similarly longer than the distance (distance 701) from the main guide bar center 700 to the center of the optical axis.

[0041] As described above, in this embodiment, each ball bearing has a contact point with respect to main guide bar 602. By configuring the ball bearings to contact main guide bar 602 at a total of four contact points, it is possible to determine the inclination of guide unit base 407 and barrel unit 404.

[0042] Furthermore, the ball bearing, main yoke 412, and main magnet 413 overlap with a joint 601a of the base 601 on the image surface side when viewed from the optical axis 70 direction. In other words, by configuring the guide unit base 407 and the joint 601a so that they overlap when viewed from the optical axis 70 direction, it is possible to provide a width in the radial direction (direction perpendicular to the optical axis), thereby making it possible to configure the opening small and increase the strength of the base 601. As will be described later, the main yoke 412 is fixed to the guide unit base 407 by screws 414a, 414b, and 414c. In other words, the guide unit base 407 also has a main yoke (reinforcing member) 412.

[0043] The above-described configuration makes it possible to bring main guide bar 602 closer to barrel unit 404. Furthermore, because lens barrel 10 is cylindrical, the ball bearings, main magnet 413 as a biasing means, and main yoke 412 can be arranged on an arc centered on optical axis 70, making it possible to reduce the diameter of fourth group unit 400.

[0044] 6 is a cross-sectional view for explaining the elements that make up the guide in this embodiment. As described above, the base 601 holds one end of the main guide bar 602 on the object side in the optical axis direction. The fifth group barrel holds the other end of the main guide bar 602 on the image surface side in the optical axis direction. As described above, the guide unit base 407 is guided by ball bearings that come into contact with the main guide bar 602 at four points.

[0045] With this configuration, when the lens barrel is viewed along the optical axis from the object side, the barrel unit 404, main guide bar 602, guide unit base 407, four ball bearings, main magnet 413, and main yoke 412 overlap with the base 601. When viewed from the image surface side in the optical axis direction, the guide unit base 407, four ball bearings, main magnet 413, and main yoke 412 overlap with the base 601.

[0046] That is, base 601 in this embodiment can connect the spaces of guide unit base 407, four ball bearings, main magnet 413, and main yoke 412 front and rear. This makes it possible to ensure the strength of base 601 and hold fourth group unit 400 with high precision. Also, as described above, because main guide bar 602 can be brought closer to barrel unit 404, it is possible to configure lens barrel 10 in a smaller size.

[0047] The main guide bar 602 does not overlap the base 601 when viewed from the image surface side in the optical axis direction, and is held by the five-group lens barrel. The lens barrel unit 404 does not overlap the base 601 when viewed from the image surface side in the optical axis direction, and is configured so that it can be inserted into the inner diameter of the base 601 from the image surface side. The assembly method and the configuration that enables this assembly method will be described later.

[0048] Clearance 713 (third clearance) is the distance between barrel unit 404 on the object side and third group cover 302 constituting third group unit 300, which is the closest part in the direction of optical axis 70. At this time, third group cover 302 is fixed to the third group barrel with screws (not shown), and the third group barrel is fixed to base 601 with screws (not shown). In other words, third group cover 302 is a fixed member (first fixed member) that is fixed to base 601.

[0049] Moreover, clearance 714 (fourth clearance) is the distance between guide unit 406 on the object side and base 601, which is the closest part in the direction of optical axis 70. Clearance 713 is a clearance smaller than clearance 714. In other words, the distance of clearance 713 is shorter than the distance of clearance 714 in the direction of optical axis 70. At this time, clearance 713 is the smallest in the lens barrel 10 state compared to clearance 714. In this way, by providing clearances 713 and 714 in lens barrel 10, when colliding with the object side, barrel unit 404, which is heavy for holding lens 401, collides first. In other words, barrel unit 404 collides with the third group cover, and then guide unit 406 collides with base 601.

[0050] In other words, because the energy of fourth group unit 400 at the time of collision is consumed when it collides with third group cover 302, it is possible to reduce the energy applied between lens barrel unit 404 and guide unit 406. As a result, it is possible to prevent changes in the connection state between lens barrel unit 404 and guide unit base 407. In other words, it is possible to suppress changes in the inclination of lens 401 relative to main guide bar 602, and to suppress deterioration of optical performance due to impact.

[0051] Moreover, the clearance 715 (fifth clearance) is the distance between the barrel unit 404 on the image surface side and the buffer member 502 fixed to the fifth group barrel, which is the closest part in the optical axis 70 direction. In other words, the buffer member 502 is a fixed member (second fixed member) fixed to the base 601. Moreover, the clearance 716 (sixth clearance) is the distance between the guide unit 406 on the image surface side and the base 601, which is the closest part in the optical axis 70 direction. The clearance 715 is a clearance smaller than the clearance 716. In other words, the distance of the clearance 715 is shorter than the distance of the clearance 716 in the optical axis direction. At this time, the clearance 715 is smaller than the clearance 716 in the lens barrel 10 state, and the same as described above can be said on the image surface side.

[0052] Fig. 7 is a cross-sectional view for explaining elements constituting the position detection of the fourth group unit 400 in this proposal. Here, as shown in Fig. 7, a scale 415 for detecting the absolute position of the lens is fixed to the guide unit base 407. In addition, a detection sensor (light emitting sensor) 610 that can detect the absolute position of the lens by emitting light to the scale 415 and receiving reflected light is fixed to the outer periphery side of the base 601. The above-mentioned scale 415 for position detection and detection sensor 610 also function as a position detection means that can detect the position of the lens.

[0053] As described above, guide unit base 407 comes into contact with main guide bar 602, and the inclination is determined. In addition, main guide bar 602 is held by base 601 and the fifth group barrel. In other words, by holding scale 415 on guide unit base 407 as in this configuration, the inclination of scale 415 with respect to optical axis 70 due to component defects can be reduced, and the position of fourth group unit 400 can be detected with high accuracy.

[0054] When viewed from the direction of optical axis 70, ball bearing unit 411a and scale 415 overlap. Furthermore, when viewed from the direction of optical axis 70, at least ball bearing unit 411a and detection sensor 610 overlap. Guide unit 406 rotates about main guide bar 602 so as to absorb component errors for holding ball bearing 419. Here, by configuring lens barrel 10 of this embodiment, it is possible to reduce changes in the clearance between scale 415 and detection sensor 610 due to rotation.

[0055] The scale 415 is disposed on the object side with respect to each ball bearing. The fixed portion of the guide unit base 407 and the barrel unit 404 is on the image plane side. In this case, the reinforcing plate 417a and the reinforcing plate 417b extend on both sides in the optical axis direction with the main yoke 412 in between.

[0056] The reinforcing plates 417a and 417b are members having a different rigidity from the guide unit base 407. Specifically, the reinforcing plates 417a and 417b are made of a metal having a higher Young's modulus than the guide unit base 407, and are insert-molded into the guide unit base 407. The reinforcing plates 417a and 417b are provided on the guide unit base 407 so as to straddle the fixing portion (screw 418a) and the first and second contacts 702 and 704 when viewed from the direction perpendicular to the optical axis. This has the effect of suppressing the shaking of the scale 415 due to vibration, and makes it possible to provide a structure that is resistant to disturbances such as vibration.

[0057] Similarly, the main yoke 412 is made of a metal having a higher Young's modulus than the guide unit base 407, and is fixed to the guide unit base 407 by screws 414a, 414b, and 414c with ball bearing 408a sandwiched therebetween. The main yoke 412 is fixed to the guide unit base 407 so as to straddle the fixed portion (screw 418a) and the first and second contacts 702 and 704 when viewed from the direction perpendicular to the optical axis. This has the effect of suppressing the shaking of the scale 415 due to vibration, as described above, and makes it possible to provide a structure that is resistant to external disturbances such as vibration.

[0058] As described above, detection sensor 610 is disposed outside (on the outer periphery) of base 601 that holds each lens, and is configured to emit light outward with respect to optical axis 70, thereby preventing the emitted light from exposing image sensor 30 to the inside, that is, from causing ghosts. In addition, the same effect can be obtained by disposing detection sensor 610 closer to the object side than fourth group unit 400.

[0059] FIG. 8 is an example of an exploded perspective view of the lens barrel 10 of this embodiment. A method for assembling the lens barrel 10 of this embodiment will be described with reference to FIG. 8. A front base yoke 605a and a front yoke base 605b used in the VCM are fixed to the base 601 from the image surface side in the optical axis direction with screws. Next, a center yoke 606a and a center yoke 606b used in the VCM are inserted and held in holes in the base 601 and the front base yoke. Then, a main guide bar 602 and a sub guide bar 603 that hold the fourth group unit 400 movably in the optical axis 70 direction are inserted and held in holes in the base 601 from the rear side in the optical axis direction.

[0060] Thereafter, the barrel unit 404 is inserted from the image surface side in the optical axis direction and accommodated in the inner diameter side of the base 601. Then, the axes of the center yoke 606a and the center yoke 606b, and the rear base yoke 609a and the rear base yoke 609b used for the VCM are inserted from the image surface side in the optical axis direction. At this time, the rotation of the rear base yoke 609a and the rear base yoke 609b is restricted by the base 601. Then, a five-group barrel having holes for holding the main guide bar 602, the sub guide bar 603, the center yoke 606a, and the center yoke 606b is fixed to the base 601 with screws from the image surface side in the optical axis direction.

[0061] Next, a method of incorporating the guide unit 406 into the lens barrel unit 404 will be described in detail. The guide unit 406 is fixed to the lens barrel unit 404 by tightening the screws 418a, 418b, 418c, 418d, 418e, and 418f, which function as fixing parts, from the outside with the optical axis 70 as the center. When the screws are tightened (when the screws are fixed), as described above, the lens barrel unit 404 is inside the base 601, and in this state, the lens barrel unit 404 has a hole (hole portion) 611 that allows direct access to the holding structure of the lens barrel unit 404. That is, the hole 611 is formed so as to penetrate within the movable range of the lens barrel unit 404. Although the details will be described later, by holding the lens barrel base 403 through the hole 611, it is possible to assemble the main guide bar 602 and the ball bearing in a separated state. Here, if the screw is tightened in a state where the ball bearing is in contact with the main guide bar 602, a dent may be made in the guide bar. Therefore, by adopting a configuration that allows the components to be assembled apart as in this embodiment, the possibility of dents occurring can be reduced.

[0062] In this embodiment, the ball bearings are biased against main guide bar 602 to guide fourth group unit 400. In this structure, if a dent occurs in the area of ​​main guide bar 602 where the ball bearings contact, fourth group unit 400 will vibrate when it passes over the dent during driving, which may cause a deterioration in the drive characteristics of the VCM. In other words, by assembling the ball bearings away from main guide bar 602, it is possible to prevent a deterioration in the drive characteristics of the VCM.

[0063] Fig. 9 is an external view illustrating the receiving surface of barrel unit 404 when guide unit base 407 is assembled. Note that Fig. 9 is an external view as seen from the opposite side of guide unit base 407. At this time, fourth group unit 400 is in a position within a range in which it can be driven as a unit. Also, at this time and in this position, barrel base 403 has holding surface 426, positioning hole 427, and rotation restriction groove 428 that are approximately perpendicular to the screw fastening direction accessible via hole 611. Each of these also functions as a holding structure capable of holding the barrel.

[0064] At this time, the hole 611 has a size that allows access to at least a part of the holding surface 426, the positioning hole 427, and the rotation restriction groove 428 in a certain phase in which the lens barrel base 403 can be driven. The holding surface 426 is a surface having a tangent provided on the side opposite the fixing portion (screw 418a) across the optical axis 70 when viewed from the direction along the optical axis 70. The holding surface 426 is provided approximately directly below six screws (fixing portions) represented by the screw 418a. Then, when fixing the screws, a jig for receiving the screws is inserted through the hole 611, and the holding surface 426 can be supported by the jig. At the same time, the same jig is used to insert two pins provided on the jig into the positioning hole 427 and the rotation restriction groove 428, thereby suppressing the rotation of the lens barrel unit 404. In other words, the rotation during screw tightening can be suppressed. Therefore, the rotational force of the screws causes the lens barrel unit 404 and the guide unit base 407 positioned on the lens barrel unit 404 to rotate, making it possible to prevent the ball bearings and main guide bar 602 from coming into contact with each other.

[0065] 10 is a cross-sectional view for explaining the position of the hole 611. The hole 611 is provided in an area on the opposite side of the guide unit base 407 with the optical axis 70 interposed therebetween, on a plane perpendicular to the optical axis 70.

[0066] A tangent line 707 at first contact point 702, which is the contact point between main guide bar 602 and the ball bearing, and a line parallel to this and passing through optical axis 70 are designated as line 708. By applying a force to barrel unit 404 and guide unit base 407 in a direction perpendicular to line 708 and in the direction of ball bearing 408a, it is possible to separate ball bearing 408a and main guide bar 602. In other words, when a circle is drawn with optical axis 70 as its center, it is divided by line 708, and by receiving barrel unit 404 at a tangent on the arc in the area where ball bearing 408a is not present, it is possible to separate ball bearing 408a and main guide bar 602.

[0067] Also, when a line 710 is parallel to a tangent 709 at the second tangent point 704 and passes through the optical axis 70, the ball bearing 408b and the main guide bar 602 can be assembled at a distance by receiving them in a similar manner. In other words, when a circle is drawn with the optical axis 70 as its center, the ball bearing can be assembled at a distance by providing a receiving surface in an area that faces the main guide bar 602 across the optical axis 70 in an area divided by lines 708 and 710. In this way, the hole 611 is provided in an area on a plane perpendicular to the optical axis 70, which is divided by a line that is parallel to the tangent (line 708) at the first tangent point 702 and the tangent (line 710) at the second tangent point 704 and passes through the optical axis.

[0068] Next, the relationship between the barrel unit 404 and the base 601 when the holding surface 426 is received will be described with reference to FIG. 5. The barrel base 403 has a clearance 711 (first clearance) in the radial direction (direction perpendicular to the optical axis), that is, in the direction connecting the optical axis 70 and the center of the main guide bar 602, in the lens barrel 10 state. At this time, the clearance 711 is formed between the main guide bar 602 and a convex portion 430 that is spaced apart in the optical axis 70 direction from the convex portion 429 provided on the barrel base 403. That is, the barrel base 403 has the convex portion 429 and the convex portion 430 as two convex portions formed between the main guide bar 602 and spaced apart in the optical axis 70 direction. In addition, the barrel base 403 has a clearance 712 (second clearance) between the base 601 and the barrel unit 404 in the radial direction or in the direction connecting the optical axis 70 and the center of the main guide bar 602.

[0069] At this time, the clearance 711 is smaller than the clearance 712. In other words, when the holding surface 426 is held by a jig, the base 601 falls in the direction of the jig, so that the main guide bar 602 comes into contact with the convex parts 429 and 430 and is held. The convex parts 429 and 430 also function as part of the holding structure in the lens barrel 10. At this time, the convex parts 429 and 430 do not come into contact with each other in the lens barrel 10 state, so even if the contact causes a dent or the like, it does not affect the driving characteristics of the VCM. In addition, since the main guide bar 602 and the barrel unit 404 come into direct contact with each other, even if the barrel base 403 is deformed by the force of the screw tightening, it is linked to the deformation of the barrel base 403. As a result, the position of the main guide bar 602 changes, so that it is possible to suppress contact between the ball bearing and the main guide bar 602.

[0070] As described above, by using lens barrel 10 having the configuration described above, it is possible to provide an imaging device that has a small lens barrel with good optical performance.

[0071] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. For example, the VCM may be configured with a configuration other than that described above, that is, with other actuators. In addition, in this embodiment, an example of four ball bearings is shown, but a configuration may be provided in which two guide units each having two ball bearings whose contact points do not coincide with the optical axis 70 direction are provided. In addition, a configuration in which three ball bearings are located at positions spaced apart from each other in the optical axis 70 direction, and the two contact points when viewed from the optical axis 70 direction are approximately coincident (in phase), but differ by one point.

[0072] In this embodiment, an example has been given of two ball bearings that are substantially aligned in the direction of the optical axis 70, but they may be configured so as not to be aligned in the direction of the optical axis 70. Similarly, they may be configured so that the ball bearings at the front and rear of the optical axis do not overlap in the direction of the optical axis 70.

[0073] In the present embodiment, holes and grooves are used as an example of the holding means for preventing rotation when the screws are tightened. However, the rotation preventing means may be formed in the form of grooves or convex shapes.

[0074] Also, in this embodiment, an example has been given in which the holes and the holding structure are provided on the side facing the guide bar across the optical axis 70. However, this is not limiting, and two holes may be provided on either side of the line connecting the guide bar and the optical axis 70, and holding structures may be provided on both sides to hold the lens barrel unit.

[0075] The above-described embodiments are merely representative examples, and various modifications and alterations are possible for each embodiment when implementing the present invention.

[0076] The disclosure of this embodiment includes the following configuration.

[0077] (Configuration 1) Lenses and a lens barrel that holds the lens and is movable in a direction along an optical axis; a cylindrical base member located on the outer periphery of the lens barrel; A guide bar having at least one end fixed to the base member; a holding member for holding the other end of the guide bar; a guide unit fixed to the lens barrel by a fixing portion and having a biasing means for biasing the first rotating element and the second rotating element to the guide bar, in a plane perpendicular to the optical axis, a distance from a first contact point, which is a point where the guide bar and the first rotating element are in contact, a distance from a second contact point, which is a point where the guide bar and the second rotating element are in contact, and the biasing means to the center of the optical axis is longer than a distance from the center of the guide bar to the center of the optical axis; When viewed from both sides in a direction along the optical axis, the guide unit overlaps with the base member, When viewed along the optical axis, the biasing means is disposed between the first contact and the second contact. A lens barrel characterized by:

[0078] (Configuration 2) a hole portion that passes through within a movable range of the lens barrel when the lens barrel, the base member, the guide bar, the holding member, and the guide unit are fixed; The lens barrel according to configuration 1, further comprising a holding structure capable of holding the lens barrel via the hole.

[0079] (Configuration 3) The lens barrel described in configuration 1 or 2, characterized in that a first clearance, which is a clearance between the barrel and the guide bar in a direction perpendicular to the optical axis, is smaller than a second clearance, which is a clearance between the base member and the barrel in the direction perpendicular to the optical axis.

[0080] (Configuration 4) 4. The lens barrel according to any one of configurations 1 to 3, wherein the guide unit has a position detection means for detecting a position of the lens.

[0081] (Configuration 5) The lens barrel described in any one of configurations 1 to 4, characterized in that a third clearance, which is a clearance between the barrel and the base member or a first fixed member fixed to the base member in the optical axis direction, is smaller than a fourth clearance, which is a clearance between the barrel and the base member in the optical axis direction.

[0082] (Configuration 6) The lens barrel described in any one of configurations 1 to 5, characterized in that a fifth clearance, which is a clearance between the barrel and the base member or a second fixed member fixed to the base member in the optical axis direction, is smaller than a sixth clearance, which is a clearance between the guide unit and the base member in the optical axis direction.

[0083] (Configuration 7) the guide unit includes a guide base to which the first rotating element and the second rotating element are fixed, and a reinforcing member having a rigidity different from that of the guide base, The lens barrel described in any one of configurations 1 to 6, wherein the reinforcing member is fixed across the fixed portion, the first contact point, and the second contact point when viewed from a direction perpendicular to the optical axis.

[0084] (Configuration 8) the guide unit has a third rotating element that overlaps with the first rotating element when viewed from the optical axis direction and is spaced apart from the first rotating element in the optical axis direction; The lens barrel described in any one of configurations 1 to 7, wherein the biasing means is located between the first contact point and a third contact point, which is a point where the third rotating element is in contact with the guide bar, in the optical axis direction.

[0085] (Configuration 9) The lens barrel described in configuration 2, wherein the hole portion is provided in a region on a plane perpendicular to the optical axis, the region being divided by a line passing through the optical axis and parallel to tangents to the first tangent point and the second tangent point.

[0086] (Configuration 10) 3. The lens barrel according to configuration 2, wherein the holding structure is formed by at least one of a groove, a hole, and a protrusion provided in the barrel.

[0087] (Configuration 11) The lens barrel described in configuration 2, wherein the holding structure is formed by a surface having a tangent provided on a side opposite to the fixed portion across the optical axis when viewed from the optical axis direction.

[0088] (Configuration 12) 5. The lens barrel according to configuration 4, wherein the position detection means is a scale for position detection provided on the guide unit, and a light emitting sensor provided on the outer periphery of the base member.

[0089] (Configuration 13) 5. The lens barrel according to configuration 4, wherein the position detection means is disposed at a position overlapping at least the first rotating element when viewed from the optical axis direction.

[0090] (Configuration 14) 14. The lens barrel according to any one of configurations 1 to 13, wherein the biasing means comprises a magnet that is attracted to the guide bar made of a soft magnetic material.

[0091] (Configuration 15) 8. The lens barrel according to claim 7, wherein the reinforcing member is a yoke that is attracted to a magnet.

[0092] (Configuration 16) The lens barrel according to configuration 7, wherein the reinforcing member is disposed at a position overlapping the first rotating element or the second rotating element when viewed from the optical axis direction.

[0093] (Configuration 17) The lens barrel according to any one of configurations 1 to 16, wherein the lens barrel has two convex portions formed between the guide bar and the guide bar and spaced apart in the optical axis direction.

[0094] (Configuration 18) A mount portion to be attached to the imaging device; The lens barrel according to any one of configurations 1 to 17, An interchangeable lens characterized by the above.

[0095] (Configuration 19) An imaging element; The lens barrel according to any one of configurations 1 to 17, 1. An imaging device comprising: [Explanation of symbols]

[0096] 1. Imaging device 10 Lens barrel 20 Camera 30 Image sensor 40 Mount 50 Operating ring 60 Main CPU 70 Optical axis 100 1st group unit 101 Lens 200 2nd group unit 201 Lens 300 3rd group unit 301 Lens 400 4th group unit 401 Lens 402 Telescope tube 403 Telescope base 404 Telescope Unit 500 5 group unit 501 Lens 601 Base 602 Main guide bar

Claims

1. Lenses and a lens barrel that holds the lens and is movable in a direction along an optical axis; a cylindrical base member located on the outer periphery of the lens barrel; A guide bar having at least one end fixed to the base member; a holding member for holding the other end of the guide bar; a guide unit fixed to the lens barrel by a fixing portion and having a biasing means for biasing the first rotating element and the second rotating element to the guide bar, in a plane perpendicular to the optical axis, a distance from a first tangential point where the guide bar and the first rotating element are in contact, a distance from a second tangential point where the guide bar and the second rotating element are in contact, and the biasing means to the center of the optical axis is longer than a distance from the center of the guide bar to the center of the optical axis; When viewed from both sides in a direction along the optical axis, the guide unit overlaps with the base member, When viewed along the optical axis, the biasing means is disposed between the first contact and the second contact. A lens barrel characterized by:

2. a hole portion that passes through within a movable range of the lens barrel when the lens barrel, the base member, the guide bar, the holding member, and the guide unit are fixed; The lens barrel according to claim 1 , further comprising a holding structure capable of holding the lens barrel via the hole.

3. 2. The lens barrel according to claim 1, wherein a first clearance, which is a clearance between the lens barrel and the guide bar in a direction perpendicular to the optical axis, is smaller than a second clearance, which is a clearance between the base member and the lens barrel in a direction perpendicular to the optical axis.

4. 2. The lens barrel according to claim 1, wherein the guide unit has a position detection means for detecting the position of the lens.

5. The lens barrel according to claim 1, characterized in that a third clearance, which is a clearance between the lens barrel and the base member or a first fixed member fixed to the base member in the optical axis direction, is smaller than a fourth clearance, which is a clearance between the lens barrel and the base member in the optical axis direction.

6. The lens barrel according to claim 1, characterized in that a fifth clearance, which is a clearance between the barrel and the base member or a second fixed member fixed to the base member in the optical axis direction, is smaller than a sixth clearance, which is a clearance between the guide unit and the base member in the optical axis direction.

7. the guide unit includes a guide base to which the first rotating element and the second rotating element are fixed, and a reinforcing member having a rigidity different from that of the guide base, The lens barrel according to claim 1 , wherein the reinforcing member is fixed to the fixing portion across the first contact point and the second contact point when viewed from a direction perpendicular to the optical axis.

8. the guide unit has a third rotating element that overlaps with the first rotating element when viewed from the optical axis direction and is spaced apart from the first rotating element in the optical axis direction; 2. The lens barrel according to claim 1, wherein the biasing means is located between the first contact point and a third contact point, which is a point where the third rotating element contacts the guide bar, in the optical axis direction.

9. The lens barrel according to claim 2 , wherein the hole is provided in a region on a plane perpendicular to the optical axis, the region being divided by a line passing through the optical axis and parallel to tangents to the first and second contact points.

10. 3. The lens barrel according to claim 2, wherein the holding structure is formed by at least one of a groove, a hole, and a protrusion provided in the barrel.

11. 3. The lens barrel according to claim 2, wherein the holding structure is formed by a surface having a tangent provided on a side opposite to the fixed portion across the optical axis when viewed in the optical axis direction.

12. 5. The lens barrel according to claim 4, wherein the position detection means comprises a scale for detecting a position provided on the guide unit, and a light emitting sensor provided on the outer periphery of the base member.

13. 5. The lens barrel according to claim 4, wherein the position detection means is disposed at a position overlapping at least the first rotating element when viewed in the optical axis direction.

14. 2. The lens barrel according to claim 1, wherein the biasing means comprises a magnet that is attracted to the guide bar made of a soft magnetic material.

15. 8. The lens barrel according to claim 7, wherein the reinforcing member is a yoke that is attracted to a magnet.

16. The lens barrel according to claim 7 , wherein the reinforcing member is disposed at a position overlapping the first rotating element or the second rotating element when viewed from the optical axis direction.

17. The lens barrel according to claim 1 , wherein the lens barrel has two convex portions formed between the guide bar and the guide bar and spaced apart in the optical axis direction.

18. A mount portion to be attached to the imaging device; and the lens barrel according to any one of claims 1 to 17. An interchangeable lens characterized by the above.

19. An imaging element; and the lens barrel according to any one of claims 1 to 17.

1. An imaging device comprising:

Images