Drive and optical device

Abstract

To provide a driving device and an optical device that allow a thrust force to be efficiently obtained and can be downsized by increasing the size in a radial direction.SOLUTION: A driving device includes: a magnetic circuit unit 31A having a first yoke 43, a second yoke 44, and a first magnet 41; a magnetic circuit unit 32A having a first yoke 43, a second yoke 44, and a second magnet 42; and a first coil connected to the focus lens 22A. The magnetic circuit units 31A and 32A drive a first coil 33 and a focus lens 22A by an electromagnetic force generated in the first coil 33. The first magnet 41 corresponds to a first movement amount AM1 for which the focus lens 22A moves, and the second magnet 42 corresponds to a second movement amount AM2 for which the focus lens 22A moves.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a driving device for driving an optical system and an optical device. [Background technology]

[0002] Patent Document 1 describes a lens driving device that includes a lens for capturing an image of a subject, a lens frame that holds the lens and has a guide hole formed approximately parallel to the optical axis of the lens, a fixed part that has a guide shaft that slidably engages with the guide hole and guides the lens frame in the optical axis direction, a coil fixed to the lens frame, a magnet that engages with the coil, and a yoke to which the magnet is attached. In this lens driving device, the yoke is configured to be movable in the direction of the optical axis of the lens.

[0003] Patent Document 2 describes a lens unit including two lens drive units, each having a yoke, a voice coil, and a plate-shaped magnet. A center point connecting line connecting the center positions of the lens drive units in a plane perpendicular to the lens optical axis is positioned so as not to pass through the lens optical axis. The width of the magnets in the lens circumferential direction is narrower than the width of the yoke, and the magnets are positioned offset toward the end of the yoke in the lens circumferential direction in the divided region where the center of the lens optical axis is located, out of the two divided regions divided by the center point connecting line. The shortest distance between the lens optical axis and the application point connecting line connecting the center positions of the lens drive units with respect to the magnets is shorter than the shortest distance between the center point connecting line and the lens optical axis. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 3765825 [Patent Document 2] Patent No. 5866487 Summary of the Invention

[0005] One embodiment of the technique of the present disclosure provides a drive device and an optical device that can efficiently obtain thrust and can be made smaller by suppressing an increase in radial dimensions. [Means for solving the problem]

[0006] One aspect of the technique disclosed herein is a driving device for driving an optical system along the optical axis direction of the optical system, the driving device including a base and a first coil, the base driving the first coil and the optical system by an electromagnetic force generated in the first coil, the base including a first base having a first magnet disposed therein corresponding to a first movement amount of the optical system, and a second base having a second magnet disposed therein corresponding to a second movement amount of the optical system. The base has a yoke and a magnet disposed in the yoke. The first coil is coupled to the optical system and corresponds to the magnet.

[0007] The magnets are preferably installed on the inner surface of the curved yoke. The lengths of the first and second magnets in the optical axis direction are preferably shorter than the maximum movement of the optical system.

[0008] It is preferable to provide a position detection sensor having a magnetic body that detects the position of the optical system by the magnetism of the magnetic body, and a magnetic suppression member that suppresses the magnetism of the first magnet and / or the second magnet within the magnetic field of the magnetic body.

[0009] It is preferable that the first base portions are arranged in a pair at positions facing each other across the optical axis, and the second base portions are arranged in a pair at positions facing each other across the optical axis.

[0010] The yoke is preferably made up of a plurality of yoke components, and the plurality of yoke components are preferably joined together at a point other than the end of the yoke in the optical axis direction.

[0011] It is preferable that a support member for supporting the yoke is provided, and that the yoke has a fixing hole formed in a position other than the end of the yoke in the optical axis direction for fixing the yoke to the support member.

[0012] It is preferable that the yoke is provided with a support member on which the yoke is supported, and the yoke is fixed to the support member by adhesion, press fitting into the support member, or holding by a holding member coupled with the support member.

[0013] It is preferable that the first coil has a cylindrical shape, and the yoke and magnet are formed in an arc shape corresponding to the cylindrical shape.

[0014] The first magnet and the second magnet may be spaced apart in the optical axis direction, or the first magnet and the second magnet may have a portion where they overlap in the optical axis direction.

[0015] An optical device according to one aspect of the technology of the present disclosure is an optical device having the above-described driving device. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 2 is an exploded perspective view of the digital camera. [Figure 2] FIG. 1 is a side view of a digital camera. [Figure 3] FIG. 2 is a cross-sectional view of a main part of a lens barrel. [Figure 4] FIG. [Figure 5] FIG. [Figure 6] FIG. [Figure 7] FIG. 2 is an exploded perspective view of a magnetic circuit unit. [Figure 8] FIG. 2 is a side view of the magnetic circuit unit. [Figure 9] 9 is a cross-sectional view of the main part of the drive device taken along line IX-IX in FIG. 6. [Figure 10] 7 is a cross-sectional view of a main part of the driving device taken along line XX in FIG. 6. [Figure 11] FIG. 4 is a cross-sectional view of a main part around a screw member that fixes the yoke. [Figure 12] 5A and 5B are explanatory diagrams illustrating the influence of the magnetic field of the first magnet and the magnetism suppressing member. [Figure 13]FIG. 1 is a block diagram showing a schematic configuration of a digital camera. [Figure 14] 10 is a cross-sectional view of a main part of the driving device in a state where the focus lens is positioned at the tip of its movement range. FIG. [Figure 15] 10 is a cross-sectional view of a main part of the drive device in a state where the focus lens has moved from the tip to the center within its movement range. FIG. [Figure 16] 10 is a cross-sectional view of a main part of the drive device in a state where the focus lens has moved from the center to the base end side within the movement range. FIG. [Figure 17] 10 is a cross-sectional view of a main part of the driving device in a state where the focus lens is positioned at the base end of its movement range. FIG. [Figure 18] FIG. 10 is an exploded perspective view of a magnetic circuit unit according to a first modified example. [Figure 19] FIG. 10 is an exploded perspective view of a magnetic circuit unit according to a second embodiment. [Figure 20] FIG. 10 is a perspective view showing a method of fixing a magnetic circuit to a lens barrel body in a second modified example. [Figure 21] 10 is an explanatory diagram illustrating a method for positioning a first magnet and a second magnet in a third modified example. FIG. [Figure 22] FIG. 13 is a cross-sectional view of a main part illustrating the arrangement of a first magnet and a second magnet in a fourth modified example. [Figure 23] FIG. 13 is a cross-sectional view of a main part illustrating the arrangement of a first magnet and a second magnet in a fifth modified example. [Figure 24] FIG. 13 is a front view of a drive device according to a sixth modified example. DETAILED DESCRIPTION OF THE INVENTION

[0017] [First embodiment] As shown in Fig. 1, a digital camera 10 includes a camera body 11 and an interchangeable lens barrel 12. A lens mount 13, a release switch 14, a power switch (not shown), and other components are provided on the front of the camera body 11. The lens mount 13 has a circular imaging opening 13A. The lens barrel 12 is detachably attached to the lens mount 13. The lens barrel 12 is an example of an optical device according to the present invention.

[0018] An imaging element 16 is built into the camera body 11. The imaging element 16 is, for example, a CMOS (Complementary Metal Oxide Semiconductor) image sensor, a CCD (Charge Coupled Device) image sensor, or an organic thin-film imaging element. The lens mount 13 is provided with a body-side signal contact 17 (see FIG. 14) inside the imaging opening 13A for electrically connecting with the lens barrel 12 for communication. The camera body 11 also has a grip portion 11A.

[0019] 2, lens barrel 12 includes lens barrel main body 21, imaging optical system 22, drive unit 23, and focus ring 24. Lens barrel main body 21 is cylindrical and holds imaging optical system 22 and drive unit 23 therein, with a lens mount 25 (see FIGS. 3 and 14) and a lens-side signal contact 26 (see FIGS. 3 and 14) provided at its rear end. When lens barrel 12 is attached to camera body 11, imaging optical system 22 forms an image of subject light on image sensor 16.

[0020] As shown in Fig. 3, driving device 23 is disposed inside lens barrel 12. Driving device 23 is a voice coil motor (hereinafter referred to as VCM) and drives focus lens 22A, which is part of imaging optical system 22. Focus lens 22A corresponds to the "optical system" in the claims. Driving device 23 is attached to lens barrel main body 21.

[0021] In the lens barrel 12, when focus adjustment is performed under the control of a camera body control unit 71 and an AF (Autofocus) processing unit 83 (described later), the focus lens 22A moves in the Z-axis direction. The Z-axis direction is the direction along the optical axis OA of the focus lens 22A. The focus lens 22A is held by a lens holding member 28. The lens holding member 28 is connected to a first coil 33 (described later).

[0022] 4, drive device 23 includes magnetic circuit units 31A, 31B, 32A, and 32B, lens holding member 28, first coil 33, position detection sensor 34, magnetic suppression member 35, lens control unit 61, and VCM driver 62. Lens control unit 61 controls the supply of electricity to first coil 33 via VCM driver 62. In addition, lens control unit 61 controls each part of lens barrel 12, as will be described later.

[0023] The magnetic circuit units 31A and 31B are also referred to as the base portion and the first base in the claims. Department The magnetic circuit units 32A and 32B correspond to the base portion and the second base portion in the claims.

[0024] 5, the first coil 33 is wound in an octagonal shape having four sides aligned with the positions of four magnetic circuit units 31A, 31B, 32A, and 32B (described later) and four sides connecting these units. The first coil 33 is coupled to the lens holding member 28. That is, the first coil 33 is coupled to the focus lens 22A via the lens holding member 28. The lens holding member 28 has a cylindrical portion 28A and a flange portion 28B.

[0025] The cylindrical portion 28A holds the focus lens 22A. The flange portion 28B protrudes from the outer peripheral surface of the cylindrical portion 28A. The flange portion 28B has an octagonal outer shape to match the first coil 33. The first coil 33 is fixed to the flange portion 28B. As a result, the first coil 33 is arranged around the optical axis OA.

[0026] Flange portion 28B is integrally formed with four through holes 28C and sensor holding portion 28D. A first yoke 43, which will be described later, is inserted through through holes 28C. Through holes 28C are formed inside the location where first coil 33 is fixed to flange portion 28B.

[0027] The sensor holding portion 28D is provided at a position outside the first coil 33. The sensor holding portion 28D holds a magnetic body 51 (see FIG. 3) that constitutes the position detection sensor 34. The position detection sensor 34 will be described later.

[0028] 6, the magnetic circuit units 31A, 31B, 32A, and 32B are arranged in pairs at positions facing each other across the optical axis OA. That is, the magnetic circuit units 31A and 31B are arranged in pairs at positions facing each other across the optical axis OA, and the magnetic circuit units 32A and 32B are arranged in pairs at positions facing each other across the optical axis OA.

[0029] As shown in FIG. 7, the magnetic circuit unit 31A includes a first magnet 41, a first yoke 43, and a second yoke 44. The first yoke 43 and the second yoke 44 are made of a magnetic material such as iron. The first yoke 43 and the second yoke 44 correspond to the yoke and yoke component in the claims. The first yoke 43 is formed in a bent shape. Specifically, the first yoke 43 is formed in a U-shape. The first yoke 43 is located on the tip side (subject side) in the Z-axis direction.

[0030] As shown in FIG. 8, the first yoke 43 has an outer flat plate portion 43A, an inner flat plate portion 43B, and a folded portion 43C connecting these flat plate portions 43A and 43B. The outer and inner flat plate portions 43A and 43B extend in the Z-axis direction. The inner surface (the surface on the optical axis OA side) of the outer flat plate portion 43A is a mounting surface 43D, and the first magnet 41 is fixed to this mounting surface 43D. The first magnet 41 is fixed to the mounting surface 43D by, for example, bonding with an adhesive. The mounting surface 43D extends in the Z-axis direction. The first yoke 43 is attached inside the lens barrel body 21 by, for example, screwing.

[0031] The first magnet 41 has, for example, an S pole magnetized on the outer flat plate portion 43A side of the first yoke 43 and an N pole magnetized on the opposite inner flat plate portion 43B side. The first magnet 41 is selected from, for example, a ferrite magnet, an alnico magnet, a samarium-cobalt magnet, a neodymium magnet, etc.

[0032] The first yoke 43 has a folded portion 43C located at the tip end and open ends 43E and 43G located at the base end. A convex portion 43F that is convex from the end face toward the base end is formed at the open end 43E of the outer flat plate portion 43A. A concave portion 43H that is concave from the end face toward the tip end is formed at the open end 43G of the inner flat plate portion 43B.

[0033] The second yoke 44 is located on the base end side (image plane side) in the Z-axis direction relative to the first yoke 43. The second yoke 44 is arranged along the X-axis direction (the tangent direction of a circle centered on the optical axis OA) and the Y-axis direction (the radial direction intersecting the Z-axis direction and the X-axis direction). The second yoke 44 is formed with a recessed portion 44A that is recessed from the outer end face in the Y-axis direction and a protruding portion 44B that is protruding from the inner end face.

[0034] The recessed portion 44A of the second yoke 44 fits into the protruding portion 43F of the first yoke 43, and the protruding portion 44B fits into the recessed portion 43H of the first yoke 43. This joins the first yoke 43 and the second yoke 44. The first yoke 43 and the second yoke 44 may be joined only by fitting the recessed portion 44A into the protruding portion 43F and the protruding portion 44B into the recessed portion 43H, or they may be joined by combining these fittings with bonding using an adhesive or the like.

[0035] 9, similar to magnetic circuit unit 31A, magnetic circuit unit 31B includes a first magnet 41, a first yoke 43, and a second yoke 44. Furthermore, magnetic circuit unit 31A and magnetic circuit unit 31B are disposed in opposing positions across the optical axis OA, and the arrangement of components is also symmetrical across the optical axis OA.

[0036] As described above, the inner flat plate portion 43B of the first yoke 43 is inserted into the through-hole 28C of the lens holding member 28. The lens holding member 28 with the inner flat plate portion 43B inserted therethrough moves along the inner flat plate portion 43B.

[0037] On the other hand, since the first coil 33 is fixed at a position outside the through hole 28C, the first coil 33 is located inside the first yoke 43 that passes through the through hole 28C. In other words, a portion of the first coil 33 is disposed inside the magnetic circuit units 31A and 31B.

[0038] In the magnetic circuit units 31A and 31B, the first magnet 41 is disposed at a position within the movement range RM in which the focus lens 22A moves, corresponding to a first movement amount AM1 by which the focus lens 22A moves. The movement range RM is the maximum movement amount of the focus lens 22A caused by the driving device 23. In this embodiment, the first movement amount AM1 is disposed at a position halfway toward the tip of the movement range RM. That is, the first magnet 41 is disposed at a position corresponding to the range from the tip to the center of the movement range RM. Therefore, the length of the first magnet 41 in the Z-axis direction is shorter than the movement range RM.

[0039] 10, the magnetic circuit units 32A and 32B include a second magnet 42, a first yoke 43, and a second yoke 44. That is, among the configurations of the magnetic circuit units 32A and 32B, the first yoke 43 and the second yoke 44 are similar to those of the magnetic circuit units 31A and 31B, but differ in that the magnetic circuit units 32A and 32B include a second magnet 42 instead of the first magnet 41.

[0040] The second magnet 42 is similar to the first magnet 41 in terms of material, magnetization direction, thickness, etc., but is installed at a different position in the Z-axis direction from the first magnet 41. Specifically, within the movement range RM, the second magnet 42 is disposed at a position corresponding to the second movement amount AM2 of the focus lens 22A. In this embodiment, the second movement amount AM2 is disposed at a position halfway along the base end side of the movement range RM. In other words, the second magnet 42 is disposed at a position corresponding to the range from the center to the base end of the movement range RM. Therefore, the length of the second magnet 42 in the Z-axis direction is shorter than the movement range RM.

[0041] Similar to the magnetic circuit unit 32A, the magnetic circuit unit 32B includes a second magnet 42, a first yoke 43, and a second yoke 44. Furthermore, the magnetic circuit unit 32A and the magnetic circuit unit 32B are disposed opposite each other across the optical axis OA, and the components are also disposed symmetrically across the optical axis OA. Similar to the magnetic circuit units 31A and 31B, a portion of the first coil 33 is disposed inside the magnetic circuit units 32A and 32B. That is, the first coil 33 is disposed in a position corresponding to the first magnet 41 and the second magnet 42.

[0042] When the VCM driver 62 energizes the first coil 33 under the control of the lens control unit 61 and generates an electromagnetic force in the first coil 33, the electromagnetic force causes the first coil 33, which is located within the magnetic field of the first magnet 41 and the second magnet 42, to move in the Z-axis direction along the inner flat plate portion 43B. When the first coil 33 is energized, an electromagnetic force is generated by the magnetic field and current (so-called Fleming's left-hand rule). By aligning the direction in which this electromagnetic force is generated with the optical axis OA, the electromagnetic force is used as a thrust to drive the first coil 33 in the Z-axis direction.

[0043] Furthermore, at the base end of outer flat plate portion 43A, i.e., at a position near open end 43E, fixing holes 43I (see FIG. 7) are formed for fixing first yoke 43 to lens barrel body 21. In this embodiment, two fixing holes 43I are arranged along the Z-axis direction. Specifically, fixing holes 43I are female-threaded holes.

[0044] 11 , magnetic circuit units 31A, 31B, 32A, and 32B are inserted into lens barrel main body 21 with inner flat plate portion 43B inserted through through hole 28C of lens holding member 28 and arranged around focus lens 22A and first coil 33. Magnetic circuit units 31A, 31B, 32A, and 32B fit into groove 21A formed in the inner circumferential surface of lens barrel main body 21. Fixing hole 21B is formed inside groove 21A. Screw member 45 is threadedly engaged with fixing hole 21B and fixing hole 43I, thereby fixing first yoke 43 to lens barrel main body 21. That is, magnetic circuit units 31A, 31B, 32A, and 32B including first yoke 43 are fixed to lens barrel main body 21.

[0045] Position detection sensor 34 is located between magnetic circuit unit 31A and magnetic circuit unit 32A (see FIG. 6). Position detection sensor 34 detects the position of lens holding member 28, i.e., focus lens 22A. Position detection sensor 34 is composed of a magnetic body 51 and a magnetic sensor 52. For example, a multi-pole magnetized magnet is used as magnetic body 51, and an MR sensor (Magnetoresistive sensor) is used as magnetic sensor 52.

[0046] The magnetic body 51 is attached to the sensor holding portion 28D of the lens holding member 28 (see FIGS. 5 and 6). The magnetic sensor 52 is attached to the lens barrel main body 21 so as to face the magnetic body 51 (see FIG. 6). The magnetic body 51 is magnetized in a pattern in which north and south poles are alternately arranged along the Z-axis direction. The width of the magnetization pattern is, for example, about 100 μm. The magnetic sensor 52 is configured using, for example, various magnetoresistive (MR) elements whose electrical resistance value changes depending on the strength of the magnetic field.

[0047] The magnetic sensor 52 outputs a pulse signal or a periodically changing electrical signal corresponding to the alternating north-south pole arrangement pattern of the magnetic body 51 to the lens control unit 61. Based on this output, the lens control unit 61 can detect the position of the lens holding member 28, i.e., the focus lens 22A. Note that the position detection sensor 34 is not limited to this, and may be configured, for example, by a hall sensor using a hall element and a magnet.

[0048] 12, the position detection sensor 34 is located between the magnetic circuit unit 31A and the magnetic circuit unit 32A, and is therefore affected by the magnetic fields of the first magnet 41 and the second magnet 42. In this embodiment, the magnetic sensor 52 constituting the position detection sensor 34 is located on the tip side of the magnetic circuit units 31A and 32A. Therefore, the magnetic sensor 52 is more susceptible to the magnetic flux (indicated by the dashed arrow in FIG. 12) of the first magnet 41, which is located closer to the tip side than the second magnet 42.

[0049] As described above, the magnetic sensor 52 is located within the magnetic field of the magnetic body 51. However, because the magnetic field of the first magnet 41 has a large influence, the magnetic sensor 52 may be affected by noise from the first magnet 41, potentially reducing the accuracy of position detection of the focus lens 22A. Therefore, in this embodiment, the magnetic suppression member 35 is provided to prevent the influence of noise from the first magnet 41. That is, the magnetic suppression member 35 is arranged in a direction such that the magnetic flux from the magnetic suppression member 35 (indicated by the two-dot chain arrow in FIG. 12 ) cancels the magnetic field from the first magnet 41. This allows the magnetic suppression member 35 to suppress the magnetism of the first magnet 41 within the magnetic field of the magnetic body 51, thereby preventing the influence of noise from the first magnet 41. Therefore, the position detection sensor 34 can detect the position of the focus lens 22A with high accuracy. The magnetic suppression member 35, like the magnetic sensor 52, is attached to the lens barrel body 21.

[0050] In this embodiment, the magnetic suppression member 35 that suppresses the magnetism of the first magnet 41 within the magnetic field of the magnetic body 51 is arranged in consideration of the influence of noise due to the first magnet, but this is not limiting, and the magnetic suppression member 35 may be arranged in consideration of the influence of noise due to the second magnet 42. In this case, the magnetic suppression member 35 is arranged in a direction that cancels out the magnetic field due to the second magnet 42. Alternatively, a magnetic suppression member that suppresses the magnetism of the first magnet 41 and a magnetic suppression member that suppresses the magnetism of the second magnet 42 within the magnetic field of the magnetic body 51 may be provided separately.

[0051] As shown in FIG. 13, the lens barrel 12 includes an imaging optical system 22, a first coil 33, a position detection sensor 34, a lens control unit 61, a VCM driver 62, a motor driver 63, motors 64 and 65, and the like.

[0052] Lens control unit 61 is made up of a microcomputer equipped with a CPU (Central Processing Unit), a ROM (Read Only Memory) that stores programs and parameters used by the CPU, and a RAM (Random Access Memory) (none of which are shown) used as work memory for the CPU, and controls each part of lens barrel 12. Lens control unit 61 is connected to a VCM driver 62, a motor driver 63, and a position detection sensor 34.

[0053] The lens control unit 61 controls the driving of the aperture unit 66, the focus lens 22A, the zoom lens 22B, etc. based on control signals from a camera body control unit 71, which will be described later.

[0054] The imaging optical system 22 includes a plurality of lenses, including a focus lens 22A and a zoom lens 22B, an aperture unit 66, and the like. The focus lens 22A moves in the direction of the optical axis OA when a first coil 33 is energized, thereby adjusting the focal length. The lens control unit 61 transmits a control signal to the VCM driver 62 to move the focus lens 22A in accordance with a control signal from the camera body 11. The VCM driver 62 energizes the first coil 33 based on the control signal, thereby driving the first coil 33. The lens control unit 61 may also detect the rotational position of the focus ring 24 using a sensor (not shown), and move the focus lens 22A in accordance with information on the rotation direction and amount.

[0055] The zoom lens 22B is driven by a motor 64 to move in the direction of the optical axis OA, constituting an electric zoom mechanism that varies the angle of view of the imaging optical system 22. In this zoom mechanism, the amount and direction of movement of the zoom lens 22B are determined, for example, in response to an operation on the camera body 11 side. The angle of view of the imaging optical system 22 can be varied by moving the zoom lens 22B.

[0056] The diaphragm unit 66 moves a plurality of diaphragm blades 66A by driving a motor 65, thereby changing the amount of light incident on the image sensor 16. The motor driver 63 controls the driving of the motors 64 and 65 based on the control of the lens control unit 61.

[0057] The camera body control unit 71 includes a CPU, a ROM that stores programs and parameters used by the CPU, and a RAM (none of which are shown) that is used as work memory for the CPU. The camera body control unit 71 controls the camera body 11 and various parts of the lens barrel 12 connected to the camera body 11. A release signal is input to the camera body control unit 71 from the release switch 14. A body-side signal contact 17 is also connected to the camera body control unit 71.

[0058] The lens side signal contact 26 comes into contact with the body side signal contact 17 when the lens mount 25 of the lens barrel 12 is attached to the lens mount 13 of the camera body 11, electrically connecting the lens barrel 12 and the camera body 11.

[0059] The shutter unit 72 is a so-called focal plane shutter, and is disposed between the lens mount 13 and the image sensor 16. The shutter unit 72 is provided so as to be able to block the optical path between the image sensor 16 and the image sensor 22, and is variable between an open state and a closed state. The shutter unit 72 is in the open state when capturing live view images and moving images. The shutter unit 72 temporarily switches from the open state to a closed state when capturing still images. The shutter unit 72 is driven by a shutter motor 73. A motor driver 74 controls the driving of the shutter motor 73.

[0060] The imaging element 16 is driven and controlled by the camera body control unit 71. The imaging element 16 has a light receiving surface made up of a plurality of pixels (not shown) arranged in a two-dimensional matrix. Each pixel includes a photoelectric conversion element, and performs photoelectric conversion on the subject image formed on the light receiving surface by the imaging optical system 22 to generate an imaging signal.

[0061] The image sensor 16 also includes signal processing circuits (none of which are shown), such as a noise reduction circuit, an auto-gain controller, and an A / D conversion circuit. The noise reduction circuit performs noise reduction processing on the image signal. The auto-gain controller amplifies the level of the image signal to an optimal value. The A / D conversion circuit converts the image signal into a digital signal and outputs it from the image sensor 16 to the bus line 76. The output signal from the image sensor 16 is image data (so-called RAW data) with one color signal for each pixel.

[0062] The image memory 75 stores one frame of image data output to the bus line 76. The image data processing unit 77 reads one frame of image data from the image memory 75 and performs known image processing such as matrix calculation, demosaic processing, gamma correction, luminance / color difference conversion, and resizing.

[0063] The LCD driver 78 sequentially inputs one frame's worth of image data that has been image-processed by the image data processing unit 77 to the image display unit 79. The image display unit 79 is provided, for example, on the rear surface of the camera body 11, and sequentially displays live view images at a regular interval. A card I / F (Interface) 81 is incorporated in a card slot (not shown) provided in the camera body 11, and is electrically connected to a memory card 82 inserted into the card slot. The card I / F 81 stores the image data that has been image-processed by the image data processing unit 77 in the memory card 82. When playing back and displaying the image data stored in the memory card 82, the card I / F 81 reads the image data from the memory card 82.

[0064] The camera body control unit 71 transmits a control signal to the lens control unit 61 to drive the focus lens 22A in accordance with the phase difference detected by the AF processing unit 83, which will be described later. Based on the control signal, the lens control unit 61 controls the VCM driver 62 to move the focus lens 22A, and detects the position of the focus lens 22A with the position detection sensor 34. The lens control unit 61 then moves the focus lens 22A to a position where the phase difference detected by the AF processing unit 83 is at a minimum value.

[0065] The camera body control unit 71 operates the aperture unit 66 in accordance with exposure information calculated by an AE (Automatic Exposure) processing unit 84, which will be described later, and sends a control signal for changing the aperture diameter to the lens control unit 61. The lens control unit 61 controls the motor driver 74 based on the control signal, and controls the aperture diameter of the aperture unit 66 so as to obtain the aperture value calculated by the AE processing unit 84.

[0066] The AE processing unit 84 calculates the integrated value of each color signal from one frame of image data. The camera body control unit 71 calculates the appropriate exposure value based on the integrated value calculated for each frame of image, and determines the aperture value so that the appropriate exposure value calculated for a preset shutter speed is achieved. The camera body control unit 71 sends a control signal to the lens control unit 61. The lens control unit 61 controls the motor driver 63 based on the control signal, and operates the aperture unit 66 to an aperture diameter that achieves the determined aperture value.

[0067] The AF processing unit 83 detects a phase difference using a pupil division method from one frame of image data. Since the technology for focus adjustment using phase difference detection is well known, a detailed description will be omitted. The camera body control unit 71 detects the position (focus position) of the focus lens 22A at which the phase difference is minimum, based on the phase difference calculated each time one frame of image is obtained by the AF processing unit 83 and the position of the focus lens 22A detected by the position detection sensor 34. The camera body control unit 71 moves the focus lens 22A to the detected focus position and stops the movement of the focus lens 22A. In this way, focus adjustment is performed automatically without any user operation.

[0068] The AF processing performed by the camera body control unit 71 and the AF processing unit 83 is not limited to focus adjustment using phase difference detection, and may also be focus adjustment using a contrast method. In this case, the AF processing unit 83 calculates an AF evaluation value, which is an integrated value of high-frequency components, from one frame of image data. The camera body control unit 71 detects the position (focus position) of the focus lens 22A where the AF evaluation value is maximum, based on the AF evaluation value calculated by the AF processing unit 83 each time one frame of image is obtained, and the position of the focus lens 22A detected by the position detection sensor 34. Thereafter, as in the case of phase difference detection, the camera body control unit 71 moves the focus lens 22A to the detected focus position and stops the movement of the focus lens 22A.

[0069] The operation of lens barrel 12 of this embodiment will be described. When lens barrel 12 is attached to camera body 11 and a power switch (not shown) is operated by a user who is taking the picture, power is supplied to each part of digital camera 10.

[0070] When the power of the digital camera 10 is turned on, the image sensor 16, the camera body control unit 71, the lens control unit 61, etc. are activated. As described above, when a control signal is received from the camera body control unit 71, or in response to information on the rotation direction and amount of the focus ring 24, the lens control unit 61 moves the focus lens 22A.

[0071] 14 to 17, the operation of moving focus lens 22A in the Z-axis direction by energizing first coil 33 will be described. Focus lens 22A is at the extreme end of movement range RM in FIG. 14, and at the extreme base end of movement range RM in FIG. 17. Note that FIGS. 14 to 17 show a cross section (A) passing through magnetic circuit unit 31A, a cross section (B) passing through magnetic circuit unit 32A, and a cross section (C) passing through magnetic circuit unit 32A. of Cross section through (B) However, to avoid complication, the lens barrel body 21 and the like are omitted. omitted is doing.

[0072] 14(A) and 14(B) toward the proximal end position shown in FIGS. 17(A) and 17(B), the VCM driver 62 energizes the first coil 33 under the control of the lens control unit 61, causing the first coil 33 to generate an electromagnetic force. As a result, as shown in FIGS. 15(A) and 15(B), the lens holding member 28 and focus lens 22A move toward the proximal end in the Z-axis direction together with the first coil 33 located within the magnetic field of the first magnet 41. As described above, the first magnet 41 is disposed at a position within the movement range RM corresponding to the first movement amount AM1, and therefore the first coil 33, the lens holding member 28, and the focus lens 22A can be driven from the distal end to the center of the movement range RM.

[0073] When the first coil 33 continues to be energized under the control of the lens control unit 61, the first coil 33 moves from the center to a position toward the base end within the movement range RM, as shown in Figures 16(A) and 16(B). As a result, the lens holding member 28 and the focus lens 22A move further toward the base end in the Z-axis direction together with the first coil 33, which is positioned within the magnetic field of the second magnet 42. Because the second magnet 42 is disposed at a position within the movement range RM that corresponds to the second movement amount AM2, the first coil 33 can be driven from the center to a position toward the base end within the movement range RM, as shown in Figures 17(A) and 17(B).

[0074] As described above, an electromagnetic force is generated in the energized first coil 33 in the magnetic field of the first magnet 41 at a position corresponding to the first movement amount of the movement range RM, and in the magnetic field of the second magnet 42 at a position corresponding to the second movement amount of the movement range RM, so that the first coil 33 can be driven from the tip to the base end of the movement range RM. This allows the lens holding member 28 and focus lens 22A, which are provided integrally with the first coil 33, to move within the movement range RM.

[0075] On the other hand, when moving focus lens 22A from the base end position shown in Fig. 17 toward the tip end position shown in Fig. 14, the direction of the current flowing through first coil 33 can be reversed. As a result, lens holding member 28 and focus lens 22A, which are integral with first coil 33, move toward the tip end of movement range RM. Then, an electromagnetic force is generated in energized first coil 33 within the magnetic field of second magnet 42 at a position corresponding to the second movement amount of movement range RM, and within the magnetic field of first magnet 41 at a position corresponding to the first movement amount of movement range RM, so that first coil 33 can be driven from the base end to the tip end of movement range RM.

[0076] As described above, drive device 23 includes magnetic circuit units 31A and 31B in which first magnet 41 is disposed corresponding to first movement amount AM1 by which focus lens 22A moves, and magnetic circuit units 32A and 32B in which second magnet 42 is disposed corresponding to second movement amount AM2. The first coil 33 and focus lens 22A are driven within movement range RM by the electromagnetic force generated in first coil 33. This allows for efficient thrust generation, thereby enabling drive device 23 and, ultimately, lens barrel 12 to be made lighter and more compact. In conventional drive devices, the length of the magnet (dimension in the optical axis direction) is determined by the movement range of the optical system, and the thickness (dimension in the radial direction of a circle centered on the optical axis) is determined by the space inside the lens barrel. Therefore, in order to generate thrust to move an optical system such as a focus lens, the only way to increase thrust was to increase the width of the magnet (dimension in the tangential direction of a circle centered on the optical axis) or the thickness of the yoke, which resulted in a larger and heavier drive device. Furthermore, if the length of the magnet is increased in accordance with the movement range RM, the magnetic force of the magnet itself will weaken due to self-demagnetization, and it will not be possible to increase the thrust efficiently in response to an increase in the width.

[0077] In contrast, in the drive device 23, the first magnet 41 is disposed at a position within the movement range RM corresponding to the first movement amount AM1, and the second magnet 42 is disposed at a position within the movement range RM corresponding to the second movement amount AM2. This allows the length of the first magnet 41 and the second magnet 42 to be shorter than the movement range RM. This reduces the attenuation of the magnetic force of the first magnet 41 and the second magnet 42 due to self-demagnetization, allowing for efficient increase in thrust relative to an increase in width. Alternatively, sufficient thrust can be obtained without increasing the width. This eliminates the need to increase the width of the magnet or the thickness of the yoke. In other words, this minimizes an increase in the radial dimension of the lens barrel 12, thereby enabling the drive device 23 and, ultimately, the lens barrel 12 to be made smaller.

[0078] [First Modification] In the above embodiment, the fixing hole 43I for fixing the first yoke 43 to the lens barrel body 21 is formed at the base end of the first yoke 43, but the present invention is not limited to this. As shown in Fig. 18, the fixing hole 43I may be formed at a position other than the end of the first yoke 43 in the Z axis direction (optical axis direction). Specifically, No. A fixing hole 43I is disposed near the center of the first yoke 43 in the Z-axis direction. It is known that in such a yoke disposed along the Z-axis direction, the density of magnetic flux (shown by the broken lines in FIGS. 14 to 17) is high at the end. However, in the first fruit In the magnetic circuit units 31A, 31B, 32A, and 32B of the embodiments, the fixing hole 43I is provided at the end position in the Z-axis direction, and therefore magnetic flux may leak from the fixing hole 43I. In other words, the magnetic flux of the first magnet 41 or the second magnet 42 cannot be used efficiently as the thrust of the first coil 33.

[0079] In contrast, in this modification, fixing hole 43I is provided at a location other than the end in the Z-axis direction, and therefore the magnetic flux density is low at the location of fixing hole 43I. That is, in addition to the same effects as in the first embodiment, magnetic flux leakage from fixing hole 43I can be suppressed, and the magnetic flux of first magnet 41 or second magnet 42 can be used without waste as thrust for first coil 33. This allows for further weight and size reduction of the drive device and lens barrel 12.

[0080] [Second embodiment] In the first embodiment, the first and second yokes constituting the magnetic circuit units 31A, 31B, 32A, and 32B are coupled at their ends in the optical axis direction. However, this is not limiting and, as shown in FIG. 1 , they may be coupled at a location other than the ends of the yokes in the optical axis direction. In this case, the magnetic circuit unit 90 includes a first magnet 41, a first yoke 91, and a second yoke 92. The first yoke 91 and the second yoke 92 are made of a magnetic material such as iron. The first yoke 91 and the second yoke 92 correspond to the yoke and yoke component in the claims. In this embodiment, the drive device 23 and the magnetic circuit units 31A, 31B, 32A, and 32B in the first embodiment are configured similarly, with the only difference being that the first yoke 43 and the second yoke 44 are replaced with the first yoke 91 and the second yoke 92. Therefore, the same reference numerals are used and a description thereof will be omitted.

[0081] The first yoke 91 is formed in a bent shape. Specifically, the first yoke 91 is formed in a U-shape. The first yoke 91 is located on the tip side (object side) in the Z-axis direction. First yoke 91 The magnet 41 has an outer flat plate portion 91A, an inner flat plate portion 91B, and a folded portion 91C connecting the flat plate portions 91A and 91B. The outer and inner flat plate portions 91A and 91B extend in the Z-axis direction. The inner surface of the outer flat plate portion 91A is an installation surface 91D, and the first magnet 41 is fixed to this installation surface 91D.

[0082] The first yoke 91 has a folded portion 91C located at the tip end and open ends 91E and 91G located at the base end. A convex portion 91F that convexly extends from the end face toward the base end is formed at the open end 91E of the outer flat plate portion 91A. A concave portion 91H that concavely extends from the end face toward the tip end is formed at the open end 91G of the inner flat plate portion 91B. The open ends 91E and 91G, the convex portion 91F, and the concave portion 91H are dividing portions.

[0083] On the other hand, the second yoke 92 is located closer to the base end (image plane side) in the Z-axis direction than the first yoke 91. The second yoke 92 has an outer flat plate portion 92A, an inner flat plate portion 92B, and a folded portion 92C connecting these flat plate portions 92A and 92B. The outer and inner flat plate portions 92A and 92B extend in the Z-axis direction. The inner surface of the outer flat plate portion 92A is a mounting surface 92D. The mounting surface 92D extends in the Z-axis direction.

[0084] The second yoke 92 has a folded portion 92C located on the base end side and open ends 92E and 92G located on the tip end side. A recess 92F that is recessed from the end face toward the base end side is formed in the open end 92E. A protrusion 92H that is protruding from the end face toward the tip end side is formed in the open end 92G of the inner flat plate portion 92B. The open ends 92E and 92G, the recess 92F, and the protrusion 92H are dividing portions.

[0085] The first yoke 91 and the second yoke 92 are coupled together by fitting the convex portions 91F with the concave portions 92F and by fitting the concave portions 91H with the convex portions 92H. The first yoke 91 and the second yoke 92 may be coupled together only by fitting the convex portions 91F with the concave portions 92F and the concave portions 91H with the convex portions 92H, or by combining these fittings with bonding using an adhesive or the like.

[0086] In the magnetic circuit unit 90, the dividing portions, that is, the open ends 91E and 91G, the convex portion 91F, the concave portion 91H, the open ends 92E and 92G, the concave portion 92F, and the convex portion 92H, are located near the center in the Z-axis direction, i.e., other than the ends. As described above, in such a yoke arranged along the Z-axis direction, the magnetic flux density is high at the ends. However, in the first fruit In the magnetic circuit units 31A, 31B, 32A, and 32B of the embodiments, the first yoke 43 and the second yoke 44 are joined at their ends in the Z-axis direction, which can cause magnetic flux leakage from the joined portion. In other words, the magnetic flux of the first magnet 41 or the second magnet 42 cannot be used efficiently as the thrust of the first coil 33.

[0087] In contrast, in this embodiment, the first yoke 91 and the second yoke 92 are joined at a location other than their ends in the Z-axis direction, so the magnetic flux density at the joint is low. That is, in addition to the same effects as the first embodiment, the magnetic flux leaking from the joint can be suppressed, so the magnetic flux of the first magnet 41 or the second magnet 42 can be used without waste as the thrust of the first coil 33. This allows the drive device and the lens barrel 12 to be further reduced in weight and size.

[0088] This embodiment may further be combined with the configuration of the first modified example. That is, fixing holes 91I and 92I for fixing first yoke 43 to lens barrel body 21 may be formed at positions other than the ends in the Z axis direction (optical axis direction). Specifically, it is preferable to provide fixing holes 91I and 92I near the dividing portion. This allows the effects of the first modified example to be obtained.

[0089] 19 illustrates a magnetic circuit unit 90 (first base portion) including a first magnet 41, but a similar configuration may also be applied to a magnetic circuit unit (second base portion) including a second magnet 42. In this case, the second magnet 42 is preferably fixed to the installation surface 92D of the second yoke 92.

[0090] [Second Modification] In each of the above embodiments and modifications, the yoke is fixed to the lens barrel body 21 by screwing, but the method of fixing to the lens barrel body is not limited to this. As in the modification shown in Fig. 20, a magnetic circuit unit 95 including a first yoke 96 may be fixed by press-fitting. Note that in this modification, the width dimension W11 of the magnetic circuit unit 95 including the first yoke 96 is slightly wider than the width dimension W12 of the groove 21A formed in the inner circumferential surface of the lens barrel body 21, but the configuration is the same as that of the magnetic circuit units 31A, 31B, 32A, 32B, and 90 of the above embodiments. The lens barrel body 21 is made of an elastically deformable material such as resin.

[0091] The magnetic circuit unit 95 is inserted into the groove 21A of the lens barrel body 21 by applying pressure. The groove 21A receives pressure from the magnetic circuit unit 95 and expands due to elastic deformation. This allows the magnetic circuit unit 95 to be inserted into the groove 21A. The groove 21A also attempts to return to its original width dimension W12 due to elastic deformation. This allows the magnetic circuit unit 95 to be fixed to the lens barrel body 21.

[0092] Furthermore, the method of fixing the yoke and magnetic circuit unit to the lens barrel main body 21 is not limited to the above, and they may be fixed using an adhesive, for example. Alternatively, a separate holding member that is connected to the lens barrel main body may be provided, and the yoke and magnetic circuit unit may be fixed using this holding member.

[0093] [Third Modification] In the above embodiments and modifications, the first magnet 41 is disposed at a position within the movement range RM that corresponds to a first movement amount AM1, and the second magnet 42 is disposed at a position within the movement range RM that corresponds to a second movement amount AM2. When disposing the first magnet 41 and the second magnet 42 in such positions, it is preferable to use jigs 98A and 98B to position the first magnet 41 and the second magnet 42 in the Z-axis direction, as in the modification shown in FIG. 21 . The jigs 98A and 98B may be removed after the first magnet 41 and the second magnet 42 are fixed to the yoke. Alternatively, the jigs 98A and 98B may be formed from a non-magnetic material such as a resin material and left as they are after the first magnet 41 and the second magnet 42 are fixed to the yoke.

[0094] [Fourth Modification] In the above embodiments and modifications, the first magnet 41 has a length dimension corresponding to a first movement amount AM1 within the movement range RM, and the second magnet 42 has a length dimension corresponding to a second movement amount AM2 within the movement range RM. That is, there is no gap between the first magnet 41 and the second magnet 42 in the Z-axis direction, i.e., the base end of the first magnet 41 and the tip end of the second magnet are aligned. The present invention is not limited to this. As shown in FIG. 22 , the first magnet 41 and the second magnet 42 may be spaced apart in the Z-axis direction. In this case, there is a gap D1 between the first magnet 41 and the second magnet 42. However, the first coil 33 may be positioned within the magnetic field of the first magnet 41 or the second magnet 42 even at the position of this gap D1. This generates an electromagnetic force in the energized first coil 33, thereby driving the first coil 33 in the Z-axis direction.

[0095] [Fifth Modification] 23 , the first magnet 41 and the second magnet 42 may have an overlapping portion D2 where they overlap in the Z-axis direction. In this case, as in the above embodiments, the first coil 33 is located within the magnetic field of the first magnet 41 and the second magnet 42. Therefore, an electromagnetic force is generated in the energized first coil 33, and the first coil 33 can be driven in the Z-axis direction. Furthermore, as described above, when there is a gap D1 between the first magnet 41 and the second magnet 42, or when there is an overlapping portion D2 where the first magnet 41 and the second magnet 42 overlap in the Z-axis direction, it is preferable that the gap D1 and overlapping portion D2 be within the tolerance of the assembly process.

[0096] [Sixth Modification] In the above embodiments and modifications, the first coil 33 is formed in an octagonal shape, and the magnetic circuit unit, yoke, first magnet, and second magnet are formed in a flat plate shape. However, the present invention is not limited to this. As in the driving device 100 shown in FIG. 24 , the first coil 101 may be formed in a cylindrical shape, and the magnetic circuit unit 102 may be formed in an arc shape corresponding to the cylindrical shape of the first coil 101. In this case, the yoke, first magnet, and second magnet constituting the magnetic circuit unit 102 are also formed in an arc shape. It is also preferable that the lens holding member 104 connected to the first coil 101 be cylindrical. In this modification, the width dimensions of the first magnet and second magnet can be increased in the circumferential direction without affecting the size of the lens barrel, thereby efficiently improving thrust. Furthermore, the increased width dimensions of the first magnet and second magnet allow the yoke to be made thinner, thereby maintaining thrust.

[0097] In each of the above embodiments, the hardware structure of processing units that execute various processes, such as the lens control unit 61 and the camera body control unit 71, is the following various processors: The various processors include a CPU (Central Processing Unit), which is a general-purpose processor that executes software (programs) and functions as various processing units, a GPU (Graphical Processing Unit), a PLD (Programmable Logic Device), which is a processor whose circuit configuration can be changed after manufacture, such as an FPGA (Field Programmable Gate Array), and a dedicated electrical circuit, which is a processor with a circuit configuration designed specifically for executing various processes.

[0098] A single processing unit may be configured with one of these various processors, or may be configured with a combination of two or more processors of the same or different types (for example, multiple FPGAs, a combination of a CPU and an FPGA, or a combination of a CPU and a GPU). Also, multiple processing units may be configured with a single processor. Examples of multiple processing units configured with a single processor include, first, a configuration in which one processor is configured with a combination of one or more CPUs and software, as typified by client or server computers, and this processor functions as multiple processing units. Second, a configuration in which a processor is used that realizes the functions of an entire system including multiple processing units on a single IC (Integrated Circuit) chip, as typified by SoCs (System On Chips). In this way, the various processing units are configured with one or more of the above-mentioned various processors as a hardware structure.

[0099] Furthermore, the hardware structure of these various processors is, more specifically, an electric circuit in the form of a combination of circuit elements such as semiconductor elements.

[0100] In the above-described embodiments, the focus lens 22A is exemplified as an optical system driven by a driving device, but the present invention is not limited to this and may be applied to a driving device that drives other optical systems. Furthermore, the optical device according to the present invention can be applied to lens barrels of smartphones, video cameras, etc. in addition to lens barrels of digital cameras. [Explanation of symbols]

[0101] 10. Digital Camera 11 Camera body 11A Grip 12 Lens barrel 13 Lens mount 13A Imaging aperture 14 Release switch 16 image sensor 17 Body side signal contact 21 Lens barrel body 21A Groove 21B Fixing hole 22 Imaging optical system 22A Focus Lens 22B zoom lens 23 Drive unit 24 Focus ring 25 lens mount 26 Lens side signal contact 28 Lens holding member 28A Cylindrical part 28B flange 28C through hole 28D Sensor holder 31A, 31B, 32A, 32B magnetic circuit unit 33 First coil 34 Position detection sensor 35 Magnetic suppression member 41 First Magnet 42 Second Magnet 43 First York 43A Outer flat plate part 43B Inner flat plate part 43C Folded section 43D installation surface 43E, 43G open end 43F convex part 43H recess 43I fixing hole 44 Second York 44A Recess 44B convex part 45 Screw member 51 Magnetic material 52 Magnetic Sensor 61 Lens control unit 62 VCM driver 63 Motor Driver 64, 65 motors 66 Aperture unit 66A aperture blades 71 Camera body control unit 72 Shutter unit 73 Shutter motor 74 Motor Driver 75 Image Memory 76 Bus Line 77 Image data processing section 78 LCD Driver 79 Image display unit 81 Card I / F (Interface) 82 Memory Card 83 AF (Autofocus) processing unit 84 AE (Automatic Exposure) processing section 90 Magnetic circuit unit 91 First York 91A Outer flat plate part 91B Inner flat plate part 91C Folded section 91D Installation surface 91E, 91G open end 91F convex part 91H recess 91I, 92I fixing hole 92 Second York 92A Outer flat plate part 92B Inner flat plate part 92C Folded section 92D installation surface 92E, 92G open end 92F Recess 92H convex part 95 Magnetic circuit unit 96 First York 98A, 98B Jig 100 Drive unit 101 First coil 102 Magnetic circuit unit 104 Lens holding member AM1 1st movement amount AM2 2nd travel amount D1 Gap D2 Overlapping part OA optical axis RM movement range W11 width dimension W12 width

Claims

1. A drive device that drives an optical system along an optical axis direction of the optical system, a base portion having a yoke and a magnet disposed on the yoke; a first coil coupled to the optical system and corresponding to the magnet; Equipped with the base portion drives the first coil and the optical system by an electromagnetic force generated in the first coil; the base portion includes a first base portion on which a first magnet corresponding to a first movement amount by which the optical system moves is disposed, and a second base portion on which a second magnet corresponding to a second movement amount by which the optical system moves is disposed, the yoke includes a first base portion yoke in which the first magnet is disposed and a second base portion yoke in which the second magnet is disposed, A driving device in which the first base portions are arranged in a pair at positions facing each other across the optical axis, and the second base portions are arranged in a pair at a position different from the first base portions in the circumferential direction of the first coil and facing each other across the optical axis.

2. The drive unit according to claim 1 , wherein the magnet is disposed on an inner surface of the curved portion of the yoke.

3. The driving device according to claim 1 , wherein the lengths of the first magnet and the second magnet in the optical axis direction are shorter than a maximum movement amount of the optical system.

4. a position detection sensor having a magnetic body and detecting a position of the optical system by magnetism of the magnetic body; The drive device according to claim 1 , further comprising a magnetism suppressing member that suppresses magnetism of the first magnet and / or the second magnet within the magnetic field of the magnetic body.

5. The yoke is composed of a plurality of yoke components, 5. The drive device according to claim 1, wherein the plurality of yoke components are coupled together at a location other than the end of the yoke in the optical axis direction.

6. a support member on which the yoke is supported, 6. The drive device according to claim 1, wherein the yoke has a fixing hole formed in a position other than an end of the yoke in the optical axis direction, for fixing the yoke to the support member.

7. a support member on which the yoke is supported, 7. The drive device according to claim 1, wherein the yoke is fixed to the support member by adhesion, press-fitting into the support member, or holding by a holding member coupled to the support member.

8. A drive device that drives an optical system along an optical axis direction of the optical system, a base portion having a yoke and a magnet disposed on the yoke; a first coil coupled to the optical system and corresponding to the magnet; Equipped with the base portion drives the first coil and the optical system by an electromagnetic force generated in the first coil; the base portion includes a first base portion on which a first magnet corresponding to a first movement amount by which the optical system moves is disposed, and a second base portion on which a second magnet corresponding to a second movement amount by which the optical system moves is disposed, the yoke includes a first base portion yoke in which the first magnet is disposed and a second base portion yoke in which the second magnet is disposed, the first coil is cylindrical; The first base portion yoke, the second base portion yoke, the first magnet, and the second magnet are formed in an arc shape corresponding to the cylindrical shape.

9. The driving device according to claim 1 , wherein the first magnet and the second magnet are arranged to be spaced apart in the optical axis direction.

10. A drive device for driving an optical system along an optical axis direction of the optical system, comprising: a base portion having a yoke and a magnet disposed on the yoke; a first coil coupled to the optical system and corresponding to the magnet; Equipped with the base portion drives the first coil and the optical system by an electromagnetic force generated in the first coil; the base portion includes a first base portion on which a first magnet corresponding to a first movement amount by which the optical system moves is disposed, and a second base portion on which a second magnet corresponding to a second movement amount by which the optical system moves is disposed, the yoke includes a first base portion yoke in which the first magnet is disposed and a second base portion yoke in which the second magnet is disposed, The first magnet and the second magnet have a portion where they overlap in the optical axis direction.

11. An optical device comprising a drive device according to any one of claims 1 to 10.

Images