Lens device

Abstract

There is a need for optical devices with a simple configuration and low driving load for optical elements. [Solution] The optical device 200 includes base members 270 and 271, a holding member 202 that holds an optical element 201 and is movable relative to the base members, a first guide member 401 fixed to the base members, a second guide member 402 fixed to the holding member, a rolling member 403 positioned between the first guide member and the second guide member, and a biasing force generating means 405 provided on the holding member or the second guide member. The movement of the holding member is guided by the rolling of the rolling member relative to the first and second guide members. The biasing force generating means generates a biasing force that biases the holding member toward the first guide member using the first guide member.

Description

Technical Field

[0004] , , , , , , , , , , , ,

[0005]

[0001] The present invention relates to an optical device in which an optical element is movable.

Background Art

[0002] In an optical device (lens device) that guides an optical element such as a lens in the optical axis direction by sliding a holding member that holds the optical element with respect to two guide bars, a gap (play) that allows sliding is provided between the holding member and the guide bars, and the play is offset by a biasing force by a spring or the like. The biasing force is set to a strength that suppresses play due to the weight of the optical element even when the posture of the optical device changes from horizontal to upward or downward. In order to reduce the driving load of the optical element due to this biasing force, Patent Document 1 discloses a configuration in which balls roll along a V-groove, and Patent Document 2 discloses a configuration in which balls roll along two guide bars.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the optical device as described above, it is required that the driving load of the optical element is small with a simple configuration.

Means for Solving the Problems

[0005] An optical device, as one aspect of the present invention, comprises a base member, a holding member that holds an optical element and is movable relative to the base member, a first guide member fixed to the base member, a second guide member fixed to the holding member, a rolling member disposed between the first guide member and the second guide member, and a biasing force generating means provided on the holding member or the second guide member. The movement of the holding member is guided by the rolling of the rolling member relative to the first and second guide members. The biasing force generating means is characterized by generating a biasing force that biases the holding member toward the first guide member using the first guide member. An imaging device having the above optical device also constitutes another aspect of the present invention. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide an optical device with a simple configuration and low driving load for optical elements. [Brief explanation of the drawing]

[0007] [Figure 1] This figure shows the configuration of the imaging device including the lens device of Example 1. [Figure 2] Perspective view of the lens holder in the lens device of Example 1 [Figure 3] Exploded perspective view of the lens device of Example 1 [Figure 4] Side view and cross-sectional view of the lens holder of Example 1 [Figure 5] Diagram showing the guide portion in the lens holder of Example 1. [Figure 6] Perspective view of the lens holder in Example 1 [Figure 7] Perspective view of the lens holder (with guide bar) in Example 1 [Figure 8] Diagram showing the relationship between the ball and the retainer in Example 1 [Figure 9] Perspective view of the lens holder of Example 2 [Figure 10] Exploded perspective view of the lens device of Example 2 [Figure 11] Side view and cross-sectional view of the lens holder of Example 2 [Figure 12] Perspective view of the lens holder of Example 2 [Figure 13] Perspective view of the lens holder of Example 3 [Figure 14] Exploded perspective view of the lens device of Example 3 [Figure 15] Perspective view and exploded perspective view of the biasing unit in the lens holder of Example 3 [Figure 16] Perspective view of the guide portion in the lens holder of Example 3 [Figure 17] Side view and cross-sectional view of the lens holder of Example 3

Mode for Carrying Out the Invention

[0008] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Embodiment

[0009] FIG. 1 shows a schematic configuration of an imaging device 100 including a lens device 200 which is an optical device of an embodiment. The lens device 200 has a drive mechanism that supports at least a part of the imaging optical system and drives in the optical axis direction in which the optical axis OA of the imaging optical system extends. The camera body 300 has an imaging element 301.

[0010] The lens device 200 and the camera body 300 are mechanically integrated by a mount (not shown). The light beam from the subject forms an image on the imaging element 301 through the imaging optical system of the lens device 200. The lens device 200 and the camera body 300 are electrically connected through electrical contacts (not shown) and can communicate with each other.

[0011] The lens 201 is an optical element that constitutes a part of the imaging optical system and is held by a lens holder 202 as a holding member. The lens holder 202 is movable in the optical axis direction along the guide 204. The drive mechanism 203 is composed of a stepping motor, a voice coil motor composed of a magnetic circuit and a field coil, etc., and drives the lens holder 202 (that is, the lens 201) in the optical axis direction.

[0012] The lens 201 in this embodiment is a focus lens that moves in the optical axis direction for focusing on subjects from the closest to infinity. However, the lens 201 may be a zoom lens that moves for zooming, or an aperture unit that changes the amount of light.

[0013] The imaging device 301 is a photoelectric conversion element such as a CMOS sensor that converts incident light into an electrical signal, and images the subject image formed by the imaging optical system.

[0014] In this embodiment, the imaging device 100 has been described as a lens-exchangeable imaging device in which the lens device 200 is detachable, but the imaging device may be a lens-integrated type having the lens device integrally.

[0015] FIG. 2 shows the lens holder 202, and FIG. 3 shows the lens device 200 disassembled. Here, the optical axis direction is the X direction, the horizontal direction when viewing the plane orthogonal to the optical axis direction from the optical axis direction is the Z direction, and the vertical direction is the Y direction.

[0016] The lens holder 202 that holds the lens 201 is guided in the optical axis direction by two fixed guide bars 401 as main guide members (first guide members) extending in the optical axis direction. Each fixed guide bar 401 is fixed to the lens barrel housing as a base member in which the front fixed frame 2 and the rear fixed frame 271 are coupled by holding the end on the subject side by the front fixed frame 270 and the end on the image side by the rear fixed frame 271. In this embodiment, each fixed guide bar 401 is formed of a magnetic material such as SUS430. SUS430 has high corrosion resistance, does not require surface treatment, has good workability, and is suitable for guide bars from the viewpoint of high mechanical accuracy such as roundness, straightness, and surface roughness.

[0017] The lens holder 202 is provided with two movable guide bars 402 as second guide members and two magnets 405 as biasing force generating means. A yoke 406, positioned on the back of each magnet 405, is magnetically attracted to and coupled to the magnet 405, and is further firmly integrated with the lens holder 202 by adhesive. In this embodiment, the two magnets 405 and the yoke 406 are positioned near both ends of the movable guide bars 402 of the lens holder 202. More specifically, the two magnets 405 and the yoke 406 are positioned so as to sandwich the center between two rolling members, which will be described later, in the optical axis direction (the direction of movement of the lens holder 202).

[0018] Between the two fixed guide bars 401 and the two movable guide bars 402, there are two balls 403, one on the object side and one on the image side, which act as rolling members, and a retainer (rolling holding member) 404 that holds them in a rotatable manner. Each ball 403 contacts the two fixed guide bars 401 and the two movable guide bars 402, respectively. These two fixed guide bars 401, two movable guide bars 402, two balls 403, and retainer 404 constitute the main guide section 400. Since the guide bars 401, 402 and the balls 403 each have high mechanical precision, the main guide section 400, which combines them, also has high mechanical precision, thereby enabling high positional accuracy of the lens 201. Rollers may be used as rolling members instead of the balls 403.

[0019] On the lens holder 202, opposite the main guide section 400 that straddles the optical axis OA, two sub-guide bars 451 are positioned. Each sub-guide bar 451 is a secondary guide member extending in the direction of the optical axis, and is fixed to the lens barrel housing by being held at the front fixing frame 270 at the subject side and at the rear fixing frame 271 at the image side. The lens holder 202 has a U-groove, through which the two sub-guide bars 451 are inserted. A ball 452 is positioned between the two sub-guide bars 451 and the flat plate 453, sandwiched in the Y direction. The ball 452 is capable of rolling while in contact with the two sub-guide bars 451 and the flat plate 453. These two sub-guide bars 451, the ball 452, and the flat plate 453 constitute the sub-guide section (third guide member) 450.

[0020] Figure 4(a) shows the lens holder 202 as seen from the main guide section, and Figure 4(b) shows the AA cross-section in Figure 4(a).

[0021] As mentioned above, the fixed guide bar 401 is made of a magnetic material, and a magnetic attractive force acts between it and the magnet 405 fixed to the lens holder 202. As shown in Figure 4(b), the magnetic attractive force F1 acts from the movable guide bar 402 towards the fixed guide bar 401, so the two balls 403 are held between the fixed guide bar 401 and the movable guide bar 402. That is, the two fixed guide bars 401 and the magnet 405 generate a biasing force as a magnetic attractive force F1, and this biasing force biases the lens holder 202 toward the two fixed guide bars 401 via the two balls 403. With this configuration, when the lens holder 202 moves in the optical axis direction along the two fixed guide bars 401, the two balls 403 roll between the two fixed guide bars 401 and the two movable guide bars 402. As a result, the driving resistance of the lens holder 202 (driving load of the driving mechanism 203) becomes extremely small.

[0022] As shown in Figure 4(b), an opening 452a is formed in one wall of the U-groove through which the two sub-guide bars 451 of the lens holder 202 are inserted. The ball 452 contacts a flat plate 453 fixed to one wall of the U-groove by screws through the opening 452a and is sandwiched between the flat plate 453 and the two sub-guide bars 451. The sub-guide portion 450 configured in this way prevents the lens holder 202 from rotating around the two balls 403 (in a plane perpendicular to the optical axis direction).

[0023] In this embodiment, the biasing means that generates a biasing force to bring the ball 452 and the sub-guide bar 451 into contact is not explicitly shown, but such a biasing means may be provided.

[0024] Figure 5(a) shows the relationship between the fixed guide bar 401, the movable guide bar 402, and the ball 403 as viewed from the Y direction. In this figure, the ball 403 is sandwiched in the Z direction between one of the two fixed guide bars 401 and one of the two movable guide bars 402. In this figure, R1 is the distance (height) from the center of the ball 403 to the contact point between the fixed guide bar 401 and the ball 403, and R2 is the height from the center of the ball 403 to the contact point between the movable guide bar 402 and the ball 403.

[0025] Figure 5(b) shows the state in which the ball 403 has rolled by an angle θ in the -X direction from the state in Figure 5(a). Let L1 be the distance traveled by the fixed guide bar 401 in the X direction relative to the center of the ball 403 that has rolled by an angle θ, and L2 be the distance traveled by the movable guide bar 402 in the -X direction. L1 is the length of the arc of a circle with radius R1 that corresponds to angle θ, and L2 is the length of the arc of a circle with radius R2 that corresponds to angle θ. Therefore, the distance traveled by the movable guide bar 402 relative to the fixed guide bar 401 is L1 + L2. Since the ball 403 rolls on both the fixed guide bar 401 and the movable guide bar 402, the driving resistance is extremely small. The main guide section 400 is set so that L1 + L2 satisfies the required travel distance of the lens holder 202.

[0026] In this embodiment, the relationship between the guide bars 401 and 402 and the ball 403 is set such that R1 > R2. This allows the length of the movable guide bar 402 required for the ball 403 to roll to be set shorter than in the case where R1 = R2.

[0027] Figure 6 shows the structure of the main guide section 400 of the lens holder 202. The lens holder 202 has a frame section 405a for fixing the magnet 405 and the yoke 406. As described above, the magnet 405 and the yoke 406, which are magnetically attracted to each other, are fixed by adhesive near both ends of the two movable guide bars 402 of the lens holder 202.

[0028] The lens holder 202 also has holes 402a through which the two movable guide bars 402 are inserted, two on the subject side and two on the image side (a total of four holes). As shown in Figure 7, the two movable guide bars 402 are held by the lens holder 202 by being inserted through the holes 402a.

[0029] Figure 8 shows a magnified view of the two movable guide bars 402, the ball 403, and the retainer 404. The upper figure is a view in the +Z direction, and the lower figure is a view in the -Z direction.

[0030] The retainer 404 has two holding parts 404a, one on the subject side and one on the image side, and a ball 403 is placed inside each holding part 404a. Openings are formed in two places in the Y direction of each holding part 404a, and the ball 403 exposed through the openings rolls while in contact with the two fixed guide bars 401. The retainer 404 prevents the two balls 403 from getting too close to each other and maintains a constant distance in the direction of their optical axes. This prevents the ball 403 from riding up onto either of the two movable guide bars 402 when the lens device 200 falls to the ground or the like and a moment acts on the lens holder 202 around the Z axis or Y axis.

[0031] As shown in the lower diagram of Figure 8, the retainer 404 has two retaining portions 404b. By inserting these retaining portions 404b between the two movable guide bars 402 and engaging them with the movable guide bars 402, the two balls 403 are prevented from falling out between the two movable guide bars 402 and the two fixed guide bars 401.

[0032] The two balls 403 roll within the range at both ends where the retainer 404 and the lens holder 202 abut in the optical axis direction. Furthermore, the rolling range of the two balls 403 is set so that, for example, even when the retainer 404 abuts against the +X end of the lens holder 202, the two balls 403 are not positioned beyond the center of the movable guide bar 402 in the +X direction. This ensures that the center of gravity of the biasing force acting from the two magnets 405 is always between the two balls 403, thus preventing one of the balls 403 from floating away from each guide bar. [Examples]

[0033] Figure 9 shows the lens holder 562 of Example 2, and Figure 10 shows the lens device including the lens holder 562 in an exploded view.

[0034] The lens holder 562 is guided in the optical axis direction by two fixed guide bars 501, which serve as the main guide members (first guide members). The two fixed guide bars 501 are held at the subject-side end by the front fixed frame 570 and at the image-side end by the rear fixed frame 571, and are fixed to the lens barrel housing which is formed by the connection of the front fixed frame 570 and the rear fixed frame 571. Each fixed guide bar 501 is made of a magnetic material, as in Embodiment 1.

[0035] A sheet metal (second guide member: hereinafter referred to as V-groove sheet metal) 502, which has two V-grooves 502a formed on the subject side and the image side, is fixed to the lens holder 562 with screws. The V-groove sheet metal 502 is made of a magnetic material, and a magnet 505, which serves as a biasing force generating means, is attracted and fixed to the center of the V-groove sheet metal 502 in the direction of the optical axis (between the two rolling members described later).

[0036] Between the two fixed guide bars 501 and the V-groove sheet metal 502, there are two balls 503, one on the subject side and one on the image side, which act as rolling members, and a retainer (rolling holding member) 504 that holds them so that they can roll. Each ball 503 contacts the two fixed guide bars 501 and the V-groove portion 502a of the V-groove sheet metal 502, respectively. The two fixed guide bars 501, the V-groove sheet metal 502, the two balls 503, and the retainer 504 constitute the main guide section 500.

[0037] On the lens holder 562, a sub-guide bar 551 is positioned on the side opposite the main guide section 500, which straddles the optical axis OA. The sub-guide bar 551 is a secondary guide member extending in the direction of the optical axis, and is fixed to the lens barrel housing by being held at the front fixing frame 570 on the subject side and at the rear fixing frame 571 on the image side. The lens holder 562 has a U-groove, and the sub-guide bar 551 is inserted into the U-groove. A bearing 552 is provided on one wall of the U-groove. The bearing 552 is in contact with the sub-guide bar 551. The sub-guide bar 551 and the bearing 552 constitute the sub-guide section (third guide member) 550. The sub-guide section 550 configured in this way prevents the lens holder 562 from rotating around the two balls 503.

[0038] In this embodiment, the biasing means that generates a biasing force to bring the bearing 552 and the sub-guide bar 551 into contact is not explicitly shown, but such a biasing means may be provided.

[0039] Figure 11(a) shows the lens holder 562 as seen from the main guide section, and Figure 11(b) shows the BB cross section in Figure 11(a).

[0040] As mentioned above, the fixed guide bar 501 is made of a magnetic material, and a magnetic attractive force acts between it and the magnet 505 fixed to the V-groove sheet metal 502. As shown in Figure 11(b), the magnetic attractive force F2 acts from the V-groove sheet metal 502 toward the fixed guide bar 501, so the two balls 503 are held between the fixed guide bar 501 and the V-groove portion 502a of the V-groove sheet metal 502. That is, the two fixed guide bars 501 and the magnet 505 generate a biasing force as a magnetic attractive force F2, and this biasing force biases the lens holder 562 toward the two fixed guide bars 501 via the two balls 503. With this configuration, when the lens holder 562 moves in the optical axis direction along the two fixed guide bars 501, the two balls 503 roll between the two fixed guide bars 501 and the V-groove sheet metal 502. As a result, the driving resistance of the lens holder 562 is made extremely small.

[0041] Figure 12 shows a magnified view of the lens holder 562, the two balls 503, and the retainer 504. The retainer 504 has two holding portions 504a, one on the subject side and one on the image side, with a ball 503 positioned within each holding portion 504a. Openings are formed at two locations in the Y direction of each holding portion 504a, and the balls 503 exposed through these openings roll while in contact with the two fixed guide bars 501. The retainer 504 prevents the two balls 503 from getting too close to each other, maintaining a constant distance between them in the optical axis direction.

[0042] A rectangular opening 504b is formed between the two retaining portions 504a of the retainer 504. Because the retainer 504 has a rectangular opening 504b, it does not interfere with the magnet 505 located in the center of the V-groove sheet metal 502 even when the retainer 504 moves in the optical axis direction.

[0043] In this embodiment, the magnet 505 is positioned between the two V-grooves 502a. Therefore, regardless of the position of the lens holder 562, the center of gravity (line of action) of the biasing force acting from the magnet 505 is always between the two balls 503, thus preventing one of the balls 503 from lifting away from the fixing guide bar 501 and the V-groove 502a.

[0044] Furthermore, since the magnets 505 are positioned between the V-grooves 502a, the dimensions of the V-groove sheet metal 502 in the optical axis direction can be reduced compared to the configuration in which magnets 405 are positioned on both sides in the optical axis direction as in Embodiment 1.

[0045] The retainer 504 has anti-slip portions 504c as projections on both sides in the Y direction. By inserting these anti-slip portions 504c inside the frame portions 502b provided on both sides in the Y direction of the V-groove sheet metal 502, the two balls 503 are prevented from sliding out from between the V-groove portion 502a and the two fixed guide bars 501.

[0046] In this embodiment, the second guide member is formed from the V-groove portion 502a of the V-groove sheet metal 502. In this case, the rolling range of the ball 503 is limited by the length of the V-groove portion 502a. Therefore, it is not always necessary to provide the retainer 504. Furthermore, the V-groove sheet metal 502 corresponds to a single component that combines the two movable guide bars 402 in Embodiment 1, and has the function of a yoke for the magnet 505 and a function of preventing the retainer 504 from coming off. [Examples]

[0047] Figure 13 shows the lens holder 662 of Embodiment 3, and Figure 14 shows the lens device including the lens holder 662 in an exploded view.

[0048] The lens holder 662 is guided in the optical axis direction by two fixed guide bars 601, which serve as the main guide members (first guide members). The two fixed guide bars 601 are held at the subject-side end by the front fixed frame 670 and at the image-side end by the rear fixed frame 671, and are fixed to the lens barrel housing which is formed by the connection of the front fixed frame 670 and the rear fixed frame 671. Unlike in embodiments 1 and 2, each fixed guide bar 601 may be formed of a metal other than a magnetic material.

[0049] The lens holder 202 is provided with two movable guide bars 602 as second guide members and a biasing unit 605 that constitutes a biasing force generating means. Two biasing units 605 are provided in the Y direction. Each biasing unit 605 is provided between two rolling members, which will be described later, in the optical axis direction.

[0050] Between the two fixed guide bars 601 and the two movable guide bars 602, there are two balls 603, one on the object side and one on the image side, which act as rolling members, and a retainer (rolling holding member) 604 that holds them in a rotatable manner. Each ball 603 contacts the respective of the two fixed guide bars 601 and the two movable guide bars 602. These two fixed guide bars 601, two movable guide bars 602, two balls 603, and retainer 604 constitute the main guide section 600.

[0051] On the lens holder 662, opposite the main guide section 600 with the optical axis OA in between, a single sub-guide bar 651 is positioned. The sub-guide bar 651 is a secondary guide member extending in the direction of the optical axis, and is fixed to the lens barrel housing by being held at the front fixing frame 670 on the subject side and at the rear fixing frame 671 on the image side. The lens holder 662 has a U-groove, and the sub-guide bar 651 is inserted into the U-groove. A bearing 652 is provided on one wall of the U-groove. The bearing 652 is in contact with the sub-guide bar 651. These sub-guide bar 651 and bearing 652 constitute the sub-guide section (third guide member) 650. The sub-guide section 650 prevents the lens holder 662 from rotating around the two balls 603.

[0052] In this embodiment, the biasing means that generates a biasing force to bring the bearing 652 and the sub-guide bar 651 into contact is not explicitly shown, but such a biasing means may be provided.

[0053] Figure 15(a) shows the external appearance of the biasing unit 605, and Figure 15(b) shows the biasing unit 605 disassembled. The biasing unit 605 has a support member 607, a shaft screw 608, and a ball bearing 609, which includes a roller (contact member) 610, a washer 611, a nut 612, and a torsion coil spring 606. The ball bearing 609, like a typical ball bearing, consists of an inner ring, an outer ring, balls, and a cage that holds the balls. The outer ring rotates with the rolling of the balls relative to the inner ring, so the driving resistance is extremely low.

[0054] The ball bearing 609 is positioned on the inner circumference of the roller 610. The shaft screw 608 is tightened in the Z direction through the inner circumferences of the ball bearing 609, the roller 610, and the washer 611, as well as through the hole 607a of the support member 607, into the nut 612. In this way, the roller 610 is mounted to the support member 607 while being rotatably held by the ball bearing 609.

[0055] Projections 607b are provided on both sides of the support member 607 in the X direction. Torsion coil springs 606 are arranged on the outer circumference of each of these projections 607b. Each torsion coil spring 606 has arm portions 606a and 606b. The arm portion 606a abuts against the abutment portion 607c of the support member 607.

[0056] Figure 16 shows a magnified view of the lens holder 662 to which two movable guide bars 602 and two biasing units 605 are attached. The biasing unit 605, which has a torsion coil spring 606 positioned as described above, has projections 607b on both sides that are incorporated into the engagement portion 607d of the lens holder 662. The arm portion 606b of the torsion coil spring 606 abuts against the abutment portion 607e of the lens holder 662. With this configuration, a rotational force is applied to the biasing unit 605 with the projections 607b as the central axis (T1, T2 in Figure 16).

[0057] Figure 17(a) shows the lens holder 662 as seen from the main guide section, and Figure 17(b) shows the CC cross section in Figure 17(a).

[0058] The two biasing units 605 sandwich the two fixed guide bars 601 from both sides in the Y direction at positions corresponding to the center of the two movable guide bars 602 in the optical axis direction. A rotational force (torque) F3 around T1 and T2 generated by the torsion coil spring 606 acts on the two biasing units 605, and this torque F3 causes the rollers 610 of the two biasing units 605 to press against the corresponding fixed guide bars 601. This pressing contact generates a reaction force F4 from the two fixed guide bars 601. As a result, a biasing force F5, which is the resultant force of the two reaction forces F4, acts from the movable guide bar 602 in the direction of the fixed guide bars 601. In this way, the two balls 603 are sandwiched and held by the two fixed guide bars 601 and the two movable guide bars 602. That is, the lens holder 662 is biased against the two fixed guide bars 601 via the two balls 603. In this configuration, as the lens holder 662 moves along the optical axis along the two fixed guide bars 601, the two balls 603 roll between the two fixed guide bars 601 and the two movable guide bars 602. This results in extremely low driving resistance for the lens holder 662.

[0059] The strength of the biasing force F5 can be adjusted by changing the spring force of the torsion coil spring 606.

[0060] Furthermore, the angle at which the biasing unit 605 and the fixed guide bar 601 come into contact is determined by the diameter of the contact surface of the roller 610, and the diameter of the contact surface is set so that the biasing force F5 acts from the movable guide bar 602 in the direction of the fixed guide bar 601. In addition to the above contact angle, the shape of the roller 610 is set so that the dimensions of the main guide section 600 in the Z and Y directions do not become too large.

[0061] The retainer 604 is provided with the anti-loosening mechanism described in Example 1. This prevents the two balls 603 from falling out between the two movable guide bars 602 and the two fixed guide bars 601.

[0062] The rolling range of the two balls 603 is restricted by the retainer 604, as in Embodiment 1. The rolling range of the two balls 603 is also set so that, for example, even when the retainer 604 abuts against the +X end of the lens holder 662, the two balls 603 are not positioned beyond the center of the movable guide bar 602 in the +X direction. As a result, the center of gravity (line of action) of the biasing force F5 is always between the two balls 603, and this prevents one of the balls 603 from lifting away from each guide bar.

[0063] In Examples 1 and 2, the biasing force of the main guide was generated using a magnet. Since magnetic biasing generates leakage flux, it can affect sensors that use magnetic force for position detection, for example. Therefore, careful consideration is needed when determining the installation position of the main guide. In contrast, when the biasing force is generated mechanically, as in Example 3, the installation position of the main guide offers greater flexibility. Furthermore, even if the biasing force needs to be changed due to a change in the mass of the lens, it is easy to adjust by simply changing the strength of the torsion coil spring 606.

[0064] Instead of the two movable guide bars 602 in this embodiment, the V-groove sheet metal used in Embodiment 2 may be used. Also, in this embodiment, the fixed guide bar and movable guide bar of the main guide are arranged radially from the optical axis center. However, in order to improve space efficiency with surrounding units, they do not necessarily have to be arranged radially from the optical axis center, for example, in a direction perpendicular to the radial direction from the optical axis center.

[0065] In each of the embodiments described above, the main guide section includes both a configuration for guiding the lens holder in the optical axis direction and a configuration for biasing the lens holder toward the fixed guide bar (reducing play). Furthermore, a biasing force generating means is provided on the lens holder or the movable guide bar or V-groove sheet metal fixed thereto. As a result, a lens device with a simple structure, few design constraints, and low drive load can be realized.

[0066] In the above embodiments, the case in which the main guide section and the sub-guide section are positioned directly opposite each other across the optical axis OA has been described, but they do not necessarily have to be positioned directly opposite each other. For example, the sub-guide section may be positioned circumferentially offset from the position directly opposite the main guide section across the optical axis OA, as long as rotation around the ball of the lens holder is restricted. In addition, in the embodiments, the case in which the sub-guide section has a configuration in which a ball or bearing rolls has been described, but a configuration in which it slides relative to a sub-guide bar may also be adopted.

[0067] The above embodiments include the following configuration.

[0068] (Composition 1) Base member and A holding member that holds an optical element and is movable relative to the base member, A first guide member fixed to the base member, A second guide member fixed to the aforementioned holding member, A rolling member disposed between the first guide member and the second guide member, The holding member or the second guide member has a biasing force generating means, The rolling member rolls against the first and second guide members, thereby guiding the movement of the holding member. The biasing force generating means is characterized by generating a biasing force that biases the holding member toward the first guide member using the first guide member. (Configuration 2) Two of the aforementioned rolling members are provided in the direction of movement of the holding member. The optical device according to configuration 1, characterized in that the center of gravity of the biasing force is located between the two rolling members. (Composition 3) The biasing force generating means is provided in two in the direction of movement. The optical device according to configuration 2, characterized in that, in the aforementioned direction of movement, the two biasing force generating means are arranged so as to sandwich the center between the two rolling members. (Composition 4) The optical device according to configuration 2, characterized in that the biasing force generating means is positioned between the two rolling members in the aforementioned direction of movement. (Composition 5) The optical device according to any one of configurations 2 to 4, characterized in that it has a rolling holding member that holds the two rolling members so that they do not approach each other in the direction of movement. (Composition 6) The first guide member is formed of a magnetic material, The optical device according to any one of configurations 1 to 5, characterized in that the biasing force generating means is a magnet that generates a magnetic attractive force as the biasing force between itself and the first guide member. (Composition 7) The optical device according to configuration 6, characterized in that the second guide member is formed of a magnetic material and functions as a yoke for the magnet. (Composition 8) The optical apparatus according to any one of configurations 1 to 6, characterized in that the biasing force generating means generates the biasing force using the reaction force from the first guide member generated by pressing the contact member against the first guide member. (Composition 9) The optical device according to any one of configurations 1 to 8, characterized in that it has a third guide member fixed to the base member and preventing the rotation of the holding member in a plane perpendicular to the direction of movement of the holding member. (Composition 10) An optical device according to any one of claims 1 to 9, An imaging device characterized by having an image sensor that captures an image of a subject through the optical element.

[0069] The embodiments described above are merely representative examples, and various modifications and changes can be made to each embodiment when implementing the present invention. [Explanation of symbols]

[0070] 100 Imaging device 200 Lens device 201 Lens 202 Lens Holder 270 Front fixed frame 271 Rear fixing frame 401 Fixed Guide Bar 402 Movable Guide Bar 403 Ball 404 Retainer 405 Magnet

Claims

1. Base member and A holding member that holds an optical element and is movable relative to the base member, A first guide member fixed to the base member, A second guide member fixed to the aforementioned holding member, A rolling member disposed between the first guide member and the second guide member, The holding member or the second guide member has a biasing force generating means, The rolling member rolls against the first and second guide members, thereby guiding the movement of the holding member. The biasing force generating means is characterized by generating a biasing force that biases the holding member toward the first guide member using the first guide member.

2. Two of the aforementioned rolling members are provided in the direction of movement of the holding member. The optical device according to claim 1, characterized in that the center of gravity of the biasing force is located between the two rolling members.

3. The biasing force generating means is provided in two in the direction of movement. The optical device according to claim 2, characterized in that, in the direction of movement, the two biasing force generating means are arranged to sandwich the center between the two rolling members.

4. The optical device according to claim 2, characterized in that the biasing force generating means is positioned between the two rolling members in the aforementioned direction of movement.

5. The optical device according to claim 2, further comprising a rolling holding member that holds the two rolling members so that they do not approach each other in the direction of movement.

6. The first guide member is formed of a magnetic material, The optical device according to claim 1, characterized in that the biasing force generating means is a magnet that generates a magnetic attractive force as the biasing force between itself and the first guide member.

7. The optical device according to claim 6, characterized in that the second guide member is formed of a magnetic material and functions as a yoke for the magnet.

8. The optical apparatus according to claim 1, characterized in that the biasing force generating means generates the biasing force using the reaction force from the first guide member generated by pressing the contact member against the first guide member.

9. The optical device according to claim 1, further comprising a third guide member fixed to the base member and preventing the rotation of the holding member in a plane perpendicular to the direction of movement of the holding member.

10. An optical apparatus according to any one of claims 1 to 9, An imaging device characterized by having an image sensor that captures an image of a subject through the optical element.

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