Multiphase linear motor, and lens unit and imaging device equipped therewith

Abstract

To provide a compact, multi-phase linear motor capable of generating sufficient thrust. [Solution] The present invention is a multiphase linear motor (10) comprising a magnetic circuit (20), a coil assembly (22) composed of a plurality of drive coils, and a movable part (18) to which the coil assembly is attached and which is slidably supported, wherein the drive coils of the coil assembly are combined such that the straight sections of other drive coils are positioned between the straight sections of one drive coil, and at least one drive coil has both ends bent in a predetermined direction outside the magnetic circuit, and the movable part is provided with coil support parts (18a) that support both ends of each drive coil, and the coil support parts are provided with a first coil receiving surface (38a) that only the drive coils whose ends are not bent contact abut, and a second coil receiving surface (38b) that all the drive coils contact.

Description

Technical Field

[0001] The present invention relates to a multiphase linear motor, and particularly to a multiphase linear motor that generates thrust in a predetermined driving direction, a lens unit including the same, and an imaging device.

Background Art

[0002] Japanese Patent Application Laid-Open No. 2024-115071 (Patent Document 1) describes a lens unit and a lens barrel including the same. This lens unit includes a frame to which an optical element is attached, a coil attached to the frame, and a yoke and a magnet arranged so as to sandwich the coil. The coil, the yoke, and the magnet constitute a linear motor that moves the frame in the optical axis direction.

[0003] Further, in this linear motor, a coil mounting table for mounting a flat coil and a coil holding portion are provided on the frame. The coil mounting table provided on the frame and the coil attached thereto are arranged in the air gap of the magnetic circuit formed by the yoke and the magnet, and are configured to receive thrust in the optical axis direction by flowing a current through the coil.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the lens unit described in Patent Document 1, the flat coil of the linear motor is fixed on a flat coil mounting base and is configured to move within the air gap of the magnetic circuit. This leads to the problem that the entire linear motor tends to become large. In particular, when the linear motor is used in optical equipment, it becomes difficult to obtain sufficient thrust while keeping it within a size that can be housed in the lens barrel.

[0006] Therefore, the present invention aims to provide a multiphase linear motor that is compact and can generate sufficient thrust, as well as a lens unit and imaging device equipped therewith. [Means for solving the problem]

[0007] To solve the above-mentioned problems, the present invention provides a multiphase linear motor that generates thrust in a predetermined driving direction, comprising: a magnetic circuit composed of a magnet and a yoke, which forms an air gap through which magnetic flux passes between a pair of opposing gap-forming surfaces; a coil assembly composed of a plurality of drive coils through which drive current flows, which is arranged between a pair of gap-forming surfaces of the magnetic circuit; and a movable part to which the coil assembly is attached and slidably supported so that the coil assembly can move in a predetermined driving direction within the air gap of the magnetic circuit, wherein the coil assembly comprises a plurality of flat drive coils, and these drive coils are one drive coil The linear sections of the other drive coils are arranged between the linear sections of the other drive coils, and at least one of the drive coils has both ends bent in a predetermined direction outside the air gap of the magnetic circuit so as not to interfere with the other drive coils that are combined with it. The movable part is provided with coil support parts that support both ends of each drive coil outside the air gap of the magnetic circuit, and the coil support parts are provided with a first coil receiving surface that contacts only drive coils whose ends are not bent, or drive coils whose ends have the smallest bending angle, and a second coil receiving surface that contacts all of the drive coils.

[0008] According to the present invention configured in this manner, since it is equipped with multiple flat drive coils and the straight sections of other drive coils are arranged between the straight sections of one drive coil, multiple drive coils can be efficiently arranged in a narrow space, and a large thrust can be generated with a small linear motor. Furthermore, according to the present invention configured as described above, since both ends of the drive coils are bent in a predetermined direction outside the air gap of the magnetic circuit, the drive coils can be arranged compactly.

[0009] Furthermore, according to the present invention configured as described above, the movable part is provided with coil support parts that support both ends of each drive coil, and this coil support part comprises a first coil receiving surface that contacts only the drive coil whose ends are not bent or whose bending angle is the smallest, and a second coil receiving surface that contacts all drive coils. As a result, the drive coils can be firmly fixed to the movable part in a narrow space, and the drive coils can be accurately positioned within the air gap.

[0010] Furthermore, the present invention is a lens unit for use attached to an imaging device, characterized by comprising a lens barrel and a multiphase linear motor of the present invention for moving at least one optical element disposed inside the lens barrel in a predetermined driving direction.

[0011] Furthermore, the present invention is an imaging device for capturing video or still images, characterized by comprising a lens unit of the present invention and an imaging device body to which the lens unit is attached. [Effects of the Invention]

[0012] According to the present invention, a multiphase linear motor, and a lens unit and imaging device equipped therewith, it is possible to obtain sufficient thrust in a compact size. [Brief explanation of the drawing]

[0013] [Figure 1]This is a cross-sectional view of a multiphase linear motor, a lens unit, and an imaging device equipped therewith, according to a first embodiment of the present invention. [Figure 2] This is a perspective view showing a multiphase linear motor according to a first embodiment of the present invention. [Figure 3] This is an exploded perspective view of a multiphase linear motor according to a first embodiment of the present invention. [Figure 4] This is a front cross-sectional view of a multiphase linear motor according to a first embodiment of the present invention. [Figure 5] This is an enlarged side cross-sectional view showing a portion of the magnetic circuit of a multiphase linear motor according to the first embodiment of the present invention. [Figure 6] This is an exploded perspective view of a multiphase linear motor according to a second embodiment of the present invention. [Figure 7] This is an exploded perspective view of a multiphase linear motor according to a third embodiment of the present invention. [Figure 8] This is an exploded perspective view of a multiphase linear motor according to a fourth embodiment of the present invention. [Figure 9] This is an exploded perspective view of a multiphase linear motor according to a fifth embodiment of the present invention. [Figure 10] This is a perspective view showing a coil assembly removed from a multiphase linear motor according to a first embodiment of the present invention. [Figure 11] This is a perspective view showing a coil assembly removed from a multiphase linear motor according to the first embodiment of the present invention, illustrating the connections of the conductors drawn from each drive coil. [Figure 12] This is a perspective view showing a modified coil assembly provided in a multiphase linear motor according to a first embodiment of the present invention. [Figure 13] This is a perspective view showing a modified coil assembly provided in a multiphase linear motor according to the first embodiment of the present invention, illustrating the connections of the conductors drawn from each drive coil. [Figure 14] This is a perspective view showing a coil assembly removed from a multiphase linear motor according to a fifth embodiment of the present invention. [Figure 15]It is a perspective view showing a coil assembly provided in the polyphase linear motor according to the fifth embodiment of the present invention, and shows the connection of the lead wires drawn from each drive coil. [Figure 16] It is a perspective view showing a modified example of the coil assembly provided in the polyphase linear motor according to the fifth embodiment of the present invention. [Figure 17] It is a perspective view showing a modified example of the coil assembly provided in the polyphase linear motor according to the fifth embodiment of the present invention, and shows the connection of the lead wires drawn from each drive coil. [Figure 18] It is a perspective view showing a further modified example of the coil assembly provided in the polyphase linear motor according to the fifth embodiment of the present invention, and shows the connection of the lead wires drawn from each drive coil.

Mode for Carrying Out the Invention

[0014] Next, an imaging device according to the first embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a cross-sectional view of a polyphase linear motor according to the first embodiment of the present invention, and a lens unit and an imaging device including the same.

[0015] As shown in FIG. 1, the imaging device 1 includes a lens unit 2 and an imaging device main body 4. The lens unit 2 includes a lens barrel 6, a plurality of lenses 8 disposed in the lens barrel 6, a focus lens 16 for focus adjustment which is an optical element, and a lens frame 18 which is a movable part to which the focus lens 16 is attached. Further, the lens unit 2 includes a polyphase linear motor 10 that drives the lens frame 18 in the direction of the optical axis A of the lens unit 2.

[0016] The lens unit 2 is attached to the imaging device main body 4 and is configured to form an image of incident light on the imaging element surface 4a. The generally cylindrical lens barrel 6 holds a plurality of lenses 8 inside, and enables focus adjustment by moving the focus lens 16 by the polyphase linear motor 10.

[0017] Furthermore, a cylindrical focus ring 12 is rotatably mounted around the lens barrel 6, which is operated to manually move the focus lens 16. When the photographer manually rotates the focus ring 12, the focus lens 16 is moved in the direction of the optical axis A, and the focus is adjusted manually.

[0018] On the other hand, the imaging device body 4 is equipped with an autofocus operation unit that is operated to initiate autofocus, which automatically moves the focus lens 16. The imaging device body 4 also has a built-in autofocus control unit 14, and based on signals from this autofocus control unit 14, the multiphase linear motor 10 moves the focus lens 16 to perform autofocus.

[0019] In other words, when the photographer half-presses the release button 4b provided on the imaging device body 4, autofocus is initiated, and the autofocus control unit 14 adjusts the position of the focus lens 16 so that the image of the subject is in focus on the image sensor surface 4a. The multiphase linear motor 10 moves the focus lens 16 to the commanded position based on the control signal from the autofocus control unit 14. In this embodiment, the imaging device 1 is a digital still camera equipped with an image sensor, but the present invention can also be applied to imaging devices such as film cameras and cameras for shooting video.

[0020] Next, with reference to Figures 2 to 5, the multiphase linear motor 10 provided in the imaging device 1 of the first embodiment of the present invention will be described. In the following description, an example is given in which a multiphase linear motor 10 according to an embodiment of the present invention is used as an actuator to drive the lens frame 18 to which the focus lens 16 is attached in the optical axis direction. Figure 2 is a perspective view showing a multiphase linear motor 10 according to a first embodiment of the present invention. Figure 3 is an exploded perspective view of the multiphase linear motor 10 according to a first embodiment of the present invention. Figure 4 is a front cross-sectional view of the multiphase linear motor 10 according to a first embodiment of the present invention. Figure 5 is an enlarged side cross-sectional view showing a portion of the magnetic circuit of the multiphase linear motor 10 according to a first embodiment of the present invention.

[0021] As shown in Figure 2, the multiphase linear motor 10 of this embodiment includes a magnetic circuit 20, a coil assembly 22 positioned in the air gap of the magnetic circuit 20, and a Hall sensor 24 (Figure 3), which is a magnetic sensor, mounted on the upper surface of the coil assembly 22. In this embodiment, the multiphase linear motor 10 is used as an actuator to drive the lens frame 18 by generating thrust in the optical axis A direction, which is a predetermined driving direction.

[0022] Specifically, as shown in Figures 2 and 4, two guide poles 26 extending in the direction of the optical axis A are mounted parallel to each other inside the lens barrel 6, and the lens frame 18 is attached to the guide poles 26 so as to be slidable in the direction of the optical axis A. In addition, the coil assembly 22 constituting the multiphase linear motor 10 is fixed to the lens frame 18, and the magnetic circuit 20 is fixed to the lens barrel 6. By passing a drive current through the coils of the coil assembly 22, a thrust in a predetermined driving direction is generated in the coil assembly 22, and the lens frame 18 attached to the coil assembly 22 is driven in the direction of the optical axis A relative to the lens barrel 6.

[0023] Next, as shown in Figures 3 and 5, the magnetic circuit 20 is composed of a yoke 28 and a magnet 30. In this embodiment, the yoke 28 is made of a ferromagnetic material and is constructed by combining a U-shaped bent plate 28a and a flat plate 28b. That is, the yoke 28 is constructed as an annular shape with opposing parallel surfaces by connecting the open end of the U-shaped bent plate 28a with the flat plate 28b.

[0024] As shown in Figure 5, in this embodiment, the magnet 30 is composed of two identical rectangular flat permanent magnets 30a and 30b. In this embodiment, the permanent magnets 30a and 30b are rare earth magnets. These permanent magnets 30a and 30b are fixed inside the parallel surfaces of the annularly formed yoke 28, extending in the direction of the optical axis A (the direction in which thrust is generated). That is, of the opposing parallel surfaces formed by the yoke 28, the permanent magnet 30a is attached to the upper surface and the permanent magnet 30b is attached to the lower surface.

[0025] As a result, the lower surface of the permanent magnet 30a and the upper surface of the permanent magnet 30b are positioned opposite each other, and magnetic flux passes through the space between these opposing surfaces. Therefore, the lower surface of the permanent magnet 30a forms an air gap forming surface 32a, and the upper surface of the permanent magnet 30b forms an air gap forming surface 32b. Furthermore, these pair of air gap forming surfaces 32a and 32b face each other, and an air gap 34 is formed between these air gap forming surfaces through which magnetic flux passes.

[0026] Next, as shown in Figure 3, in this embodiment, the coil assembly 22 consists of three drive coils 22a, 22b, and 22c, and a flexible substrate 36 is attached to its upper surface. These three drive coils 22a, 22b, and 22c are all flat, plate-shaped coils wound in a long, narrow rectangular shape with rounded corners, and the straight sections (long sides) of these drive coils are positioned within the air gap 34 (Figure 5) formed by the magnetic circuit 20. That is, in this embodiment, the three drive coils are arranged in combination in the order of drive coils 22a, 22b, and 22c, starting from the side closest to the image sensor surface 4a.

[0027] Furthermore, the ends of the drive coil 22a, which is positioned closest to the image sensor surface 4a, are not bent and extend in a straight line, while the ends of the drive coil 22b, which is positioned in the middle, are bent downwards. Also, the ends of the drive coil 22c, which is positioned furthest from the image sensor surface 4a, are bent downwards at a larger angle than the drive coil 22b. In this way, the straight portion of each drive coil is positioned within the air gap 34 of the magnetic circuit 20, and the ends on both sides of the drive coils 22b and 22c are bent downwards outside the air gap 34. Furthermore, in this embodiment, the drive coil 22a, which has no bent ends (smallest bend angle), is positioned at the end of the imaging device 1 on the image sensor surface 4a side, and the drive coils 22b and 22c are arranged adjacent to this drive coil 22a in order of increasing bend angle.

[0028] Then, the drive coil 20b is assembled from below the flat drive coil 22a, and the drive coil 22c is assembled from below that. As a result, as shown in Figure 5, one straight section of the drive coil 22b and one straight section of the drive coil 22c are positioned between the straight sections of the drive coil 22a. Also, as shown in Figure 3, both ends of the drive coil 22b, which is positioned in the middle, are located below the ends of the unbent drive coil 22a, and both ends of the drive coil 22c are located below the ends of the drive coil 22b, which is positioned in the middle. In other words, in this embodiment, the angle at which both ends are bent downwards increases in the order of drive coils 22a, 22b, and 22c.

[0029] Thus, the drive coils 22b and 22c are bent downward at both ends outside the air gap 34 of the magnetic circuit 20 so as not to interfere with other drive coils they are combined with. In this way, in this embodiment, the straight sections of other drive coils are arranged substantially without gaps between the straight sections of one drive coil that constitutes the coil assembly 22. As a result, the straight sections of each coil can be arranged adjacent to each other, and the drive coils can be arranged at a high density.

[0030] The linear sections of the drive coils 22a, 22b, and 22c configured in this way are positioned between a pair of gap-forming surfaces 32a and 32b formed by the magnetic circuit 20. As a result, the upper surface of the coil assembly 22, consisting of the drive coils 22a, 22b, and 22c, faces the gap-forming surface 32a, and the lower surface of the coil assembly 22 faces the gap-forming surface 32b. A magnetic flux is formed between the opposing pair of gap-forming surfaces 32a and 32b, and by passing a predetermined drive current through each of the drive coils 22a, 22b, and 22c, thrust is generated in the coil assembly 22 in the direction of the optical axis A (left-right direction in Figure 5).

[0031] Next, as shown in Figure 3, the flexible substrate 36 is a thin, flexible circuit board, a portion of which is attached to the upper surface of the coil assembly 22. Furthermore, three Hall sensors 24, which are magnetic sensors, are attached to the upper surface of the flexible substrate 36 in a single row in the thrust generation direction. Thus, in this embodiment, each Hall sensor 24 is attached to the surface of the coil assembly 22 facing the gap-forming surface 32a (Figure 5). The detection signal from each Hall sensor 24 is transmitted via a circuit pattern (not shown) formed on the flexible substrate 36, and the current flowing to each drive coil is controlled based on this.

[0032] Next, we will explain the magnetization state of each permanent magnet. As shown in Figure 5, the plate-shaped permanent magnets 30a and 30b are magnetized such that the north and south poles are reversed in the thickness direction. Furthermore, the magnetic poles that appear on the gap-forming surfaces 32a and 32b of each permanent magnet are magnetized such that they alternately reverse at a predetermined pitch in the longitudinal direction. Therefore, the north and south poles are repeatedly and alternately magnetized on each gap-forming surface 32a and 32b at predetermined intervals. Also, the south pole is magnetized on the gap-forming surface 32b so as to be opposite the north pole portion of the gap-forming surface 32a, and the north pole is magnetized on the gap-forming surface 32b so as to be opposite the south pole portion of the gap-forming surface 32a. In other words, the permanent magnets 30a and 30b are magnetized such that the magnetic poles are reversed at the opposing portions of the gap-forming surfaces 32a and 32b. In this embodiment, individual magnets are magnetized so that their magnetic poles reverse at a predetermined pitch. However, permanent magnets 30a and 30b can also be constructed by arranging multiple magnets so that their magnetic poles reverse at a predetermined pitch.

[0033] Furthermore, as shown in Figure 5, the longitudinal pitch at which the magnetization reverses is set to a length three times the width of each straight section of the drive coils 22a, 22b, and 22c. That is, in the state shown in Figure 5, an S pole is formed on the gap-forming surface 32a and an N pole is formed on the gap-forming surface 32b, facing the three straight sections on the right side of each adjacent drive coil. On the other hand, an N pole is formed on the gap-forming surface 32a and an S pole is formed on the gap-forming surface 32b, facing the three straight sections on the left side.

[0034] As a result, in the state shown in Figure 5, when a counterclockwise current is passed through drive coils 22a and 22b, one of the three drive coils, a current flows from the front to the back of the paper in Figure 5 through the straight sections on the right side of these drive coils 22a and 22b, generating a thrust from right to left in Figure 5. At the same time, a current flows from the back to the front of the paper in Figure 5 through the straight sections on the left side of drive coils 22a and 22b, generating a thrust from right to left in these straight sections as well. Furthermore, in the state shown in Figure 5, by passing a clockwise current through drive coils 22b and 22c, one of the three drive coils, a thrust is generated in each drive coil from left to right in Figure 5.

[0035] On the other hand, as shown in Figure 3, the three Hall sensors 24 are arranged in a row on the flexible substrate 36 in the direction of the optical axis A. These Hall sensors 24 are mounted on the surface of the coil assembly 22 that faces the gap-forming surface 32a (the upper surface of the coil assembly 22). When the coil assembly 22 is moved by the thrust acting on the coil assembly 22 (each drive coil), the magnetic field detected by each Hall sensor 24 attached to the coil assembly 22 changes. By sequentially switching which of the three drive coils carries current based on the detection signal detected by each Hall sensor 24, thrust in the desired direction can be obtained.

[0036] Next, with reference to Figures 3 and 4, the fixing structure of the coil assembly 22 to the lens frame 18 will be described. As shown in Figures 3 and 4, coil support portions 18a are provided at the upper end of the lens frame 18. These coil support portions 18a are provided on both sides of the lens frame 18 so as to be located on both sides of the yoke 28. Furthermore, as shown in Figure 2, each coil support portion 18a supports both ends of the respective drive coils 22a, 22b, and 22c outside the air gap 34 of the magnetic circuit 20. That is, the portion of each drive coil that protrudes from the air gap 34 is supported by each coil support portion 18a. Therefore, as shown in Figure 4, each drive coil is stretched between the coil support portions 18a on both sides, and there are no members supporting each drive coil between the air gap 34. As a result, each drive coil can be positioned in a location very close to the air gap forming surfaces 32a and 32b, and a large driving force can be obtained.

[0037] Furthermore, as shown in Figure 3, the upper part of each coil support portion 18a is provided with a first coil receiving surface 38a that contacts only the drive coil 22a of the three drive coils, and a second coil receiving surface 38b that contacts all three drive coils 22a, 22b, and 22c. Specifically, the first coil receiving surface 38a is an elongated rectangular surface extending perpendicular to the optical axis A, and the second coil receiving surface 38b is an elongated rectangular surface extending parallel to the optical axis A, and the first coil receiving surface 38a and the second coil receiving surface 38b form an L-shape. Each drive coil is then bonded and fixed to the coil support portion 18a while in contact with the first coil receiving surface 38a and the second coil receiving surface 38b, respectively. In this way, by supporting each drive coil with two coil receiving surfaces, the drive coils are supported over a wide area, and the drive coils can be firmly fixed.

[0038] In this embodiment, the first coil support surface 38a is formed to be approximately the same width as the straight portion of the drive coil 22a and is a plane oriented parallel to the air gap 34 of the magnetic circuit 20 (parallel to the gap-forming surface 32b). This first coil support surface 38a is provided on the side of each coil support portion 18a closest to the image sensor surface 4a and contacts one of the straight portions of the drive coil 22a, which is not bent at both ends, with its surface, thereby supporting the drive coil 22a.

[0039] On the other hand, the second coil support surface 38b is formed to be approximately the same width as the coil assembly 22, is a plane oriented parallel to the air gap 34 of the magnetic circuit 20 (parallel to the gap-forming surface 32b), and extends in the direction of the optical axis A so as to traverse the three drive coils. This second coil support surface 38b contacts the straight sections of all three drive coils 22a, 22b, and 22c, and supports each drive coil. That is, the drive coils 22b and 22c contact the second coil support surface 38b on a surface and are bent downward on the outside of the second coil support surface 38b. In this way, by fixing the three drive coils 22a, 22b, and 22c to the coil support portion 18a while they are in contact with the second coil support surface 38b, each drive coil can be accurately positioned within the air gap 34.

[0040] Furthermore, each coil support portion 18a is provided with a relief recess 38c to receive the ends of the drive coils 22b and 22c, which have both ends bent. The relief recess 38c is a recess that is lower than the first coil receiving surface 38a and the second coil receiving surface 38b. The bottom surface of the relief recess 38c is inclined to be lower outward so as to follow the ends of the drive coils 22b and 22c, which are bent downward. When fixing the coil assembly 22 to each coil support portion 18a, adhesive is filled into each relief recess 38c, then both ends of the coil assembly 22 are inserted into the relief recess 38c, and then the adhesive is allowed to harden.

[0041] Furthermore, a stepped portion 38d is formed inside the relief recess 38c, extending to a position lower than the first coil receiving surface 38a and the second coil receiving surface 38b, and higher than the bottom surface of the relief recess 38c. This stepped portion 38d is a surface formed along the first coil receiving surface 38a, with a width approximately the same as the straight portion of the drive coil 22b, and is inclined to become lower towards the outside. The bent end of the drive coil 22b is positioned along this stepped portion 38d. This allows the drive coil 22b to be firmly fixed to the coil support portion 18a.

[0042] Thus, the relief recess 38c is formed in a stepped shape to match the bending angle of each drive coil. Furthermore, by configuring the coil support portion 18a in a stepped shape, when manufacturing the lens frame 18 by resin molding, it is possible to mold it using a mold without undercuts, thereby reducing manufacturing costs.

[0043] According to the first embodiment of the present invention, the multiphase linear motor 10 is equipped with flat drive coils 22a, 22b, and 22c, and the straight sections of the other drive coils 22b and 22c are arranged between the straight sections of the drive coil 22a. As a result, multiple drive coils can be efficiently arranged in a narrow space, and a large thrust can be generated with a small linear motor. Furthermore, according to the multiphase linear motor 10 of this embodiment, both ends of the drive coils 22b and 22c are bent in a predetermined direction outside the air gap 34 of the magnetic circuit, so the drive coils can be arranged compactly.

[0044] Furthermore, according to the multiphase linear motor 10 of this embodiment, the movable lens frame 18 is provided with coil support parts 18a that support both ends of the drive coils 22a, 22b, and 22c, respectively. This coil support part 18a includes a first coil receiving surface 38a that only the drive coil 22a, whose ends are not bent, contacts, and a second coil receiving surface 38b that all of the drive coils 22a, 22b, and 22c contact. As a result, the drive coils can be firmly fixed to the lens frame 18 in a narrow space, and the drive coils can be accurately positioned within the air gap 34.

[0045] Furthermore, according to the multiphase linear motor 10 of this embodiment, the coil support portion 18a of the lens frame 18 is provided with relief recesses 38c that receive the drive coils 22b and 22c, whose ends are bent. Therefore, by bonding the bent ends of the drive coils 22b and 22c to the relief recesses 38c, the drive coils can be more firmly fixed to the lens frame 18.

[0046] Furthermore, in the multiphase linear motor 10 of this embodiment, the coil assembly 22 has a drive coil 22a, which is not bent at both ends, positioned at one end, and adjacent to this drive coil 22a, drive coils 22b and 22c are arranged in order of increasing bending angle, and the relief recess 38c of the coil support portion 18a is formed in a stepped shape to match the bending angle of the drive coil. As a result, when manufacturing the lens frame 18 by resin molding, it is possible to mold it with a mold without undercuts, thereby reducing manufacturing costs.

[0047] Next, a multiphase linear motor according to a second embodiment of the present invention will be described with reference to Figure 6. The multiphase linear motor of this embodiment differs from the first embodiment described above in the structure of the coil assembly and the structure of the coil support portion that supports it. Therefore, in the following, only the differences between the second embodiment of the present invention and the first embodiment will be described, and similar components will be denoted by the same reference numerals as in the first embodiment and their description will be omitted.

[0048] Figure 6 is an exploded perspective view of a multiphase linear motor according to a second embodiment of the present invention. As shown in Figure 6, the multiphase linear motor 100 according to the second embodiment of the present invention includes a magnetic circuit 20 and a coil assembly 122 disposed within the air gap of the magnetic circuit 20. In this embodiment as well, a magnetic sensor and a flexible substrate are attached to the upper surface of the coil assembly 122, but they are omitted from the illustration in Figure 6.

[0049] In this embodiment as well, the coil assembly 122 is composed of three drive coils 122a, 122b, and 122c. In this embodiment, the three drive coils are arranged in combination in the order of drive coils 122a, 122b, and 122c, starting from the object side (the side furthest from the image sensor surface 4a).

[0050] Furthermore, in this embodiment, both ends of the drive coil 122a, which is positioned on the object side, are not bent but extend in a straight line, while both ends of the drive coil 122b, which is positioned in the middle, are bent downwards. In addition, both ends of the drive coil 122c, which is positioned closest to the image sensor surface 4a, are bent downwards at a larger angle than the drive coil 122b. Thus, in this embodiment, the drive coil 122a, which has no bent ends (the smallest bend angle), is positioned at the object-side end of the imaging device 1. Adjacent to this drive coil 122a, the drive coils 122b and 122c are arranged in order of increasing bend angle.

[0051] On the other hand, as shown in Figure 6, coil support portions 118a are provided at the upper end of each lens frame 18. These coil support portions 118a are provided on both sides of the lens frame 18 so as to be located on both sides of the yoke of the magnetic circuit 20. Furthermore, each coil support portion 118a supports both ends of each drive coil 122a, 122b, and 122c outside the air gap 34 of the magnetic circuit 20.

[0052] Furthermore, as in the first embodiment described above, the upper part of each coil support portion 118a is provided with a first coil receiving surface 138a that only the drive coil 122a of the three drive coils contacts, and a second coil receiving surface 138b that all three drive coils 122a, 122b, and 122c contact. However, in this embodiment, the first coil receiving surface 138a extending in a direction perpendicular to the optical axis A is provided at the object-side end of the coil support portion 118a, which is different from the first embodiment.

[0053] Furthermore, each coil support portion 118a is provided with a relief recess 138c for receiving the ends of the drive coils 122b and 122c, whose ends are bent. The relief recess 138c is a recess that is lower than the first coil receiving surface 138a and the second coil receiving surface 138b, as in the first embodiment described above. However, in this embodiment, the relief recess 138c is located closer to the image sensor surface 4a than the first coil receiving surface 138a, which is different from the first embodiment.

[0054] Furthermore, similar to the first embodiment described above, a stepped portion 138d is formed inside the relief recess 138c, extending to a position lower than the first coil receiving surface 138a and the second coil receiving surface 138b, and higher than the bottom surface of the relief recess 138c. However, in this embodiment, the stepped portion 138d is provided adjacent to the first coil receiving surface 138a on the side closer to the image sensor surface 4a, which is different from the first embodiment. Thus, the relief recess 138c is formed in a stepped shape to match the bending angle of each drive coil, and becomes lower toward the side closer to the image sensor surface 4a. By configuring the coil support portion 118a in a stepped shape, when manufacturing the lens frame 18 by resin molding, it is possible to mold it with a mold without undercuts, thereby reducing manufacturing costs.

[0055] Next, a multiphase linear motor according to a third embodiment of the present invention will be described with reference to Figure 7. The multiphase linear motor of this embodiment differs from the first embodiment described above in the structure of the coil assembly and the structure of the coil support portion that supports it. Therefore, in the following, only the differences between the third embodiment of the present invention and the first embodiment will be described, and similar components will be denoted by the same reference numerals as in the first embodiment and their description will be omitted.

[0056] Figure 7 is an exploded perspective view of a multiphase linear motor according to a third embodiment of the present invention. As shown in Figure 7, the multiphase linear motor 200 according to the third embodiment of the present invention includes a magnetic circuit 20 and a coil assembly 222 disposed within the air gap of the magnetic circuit 20. In this embodiment as well, a magnetic sensor and a flexible substrate are attached to the upper surface of the coil assembly 222, but they are omitted from the illustration in Figure 7.

[0057] In this embodiment as well, the coil assembly 222 is composed of three drive coils 222a, 222b, and 222c. In this embodiment, the three drive coils are arranged in combination in the order of drive coils 222a, 222b, and 222c, starting from the side closest to the image sensor surface 4a.

[0058] Furthermore, in this embodiment, the ends of the drive coil 222a, which is positioned closest to the image sensor surface 4a, are not bent but extend in a straight line. The drive coil 222c, which is positioned closest to the object, has both ends bent and is positioned below the drive coil 222a. In addition, the ends of the drive coil 222b, which is positioned in the middle, are also bent downwards and are positioned below the drive coil 222c. Thus, in this embodiment, the bending angle of the drive coil 222b, which is positioned in the middle, is the largest, and the bending angle of the drive coil 222c, which is positioned closest to the object, is smaller than that of the drive coil 222b.

[0059] On the other hand, as shown in Figure 7, coil support portions 218a are provided at the upper end of each lens frame 18. These coil support portions 218a are provided on both sides of the lens frame 18 so as to be located on both sides of the yoke of the magnetic circuit 20. Furthermore, each coil support portion 218a supports both ends of the respective drive coils 222a, 222b, and 222c outside the air gap 34 of the magnetic circuit 20.

[0060] Furthermore, as in the first embodiment described above, the upper part of each coil support portion 218a is provided with a first coil receiving surface 238a that only the drive coil 222a of the three drive coils contacts, and a second coil receiving surface 238b that all three drive coils 222a, 222b, and 222c contact. In this embodiment as well, the first coil receiving surface 238a extending in a direction perpendicular to the optical axis A is provided on the side of the coil support portion 218a closest to the image sensor surface 4a.

[0061] Furthermore, each coil support portion 218a is provided with a relief recess 238c for receiving the ends of the drive coils 222b and 222c, whose ends are bent. The relief recess 238c is a recess that is lower than the first coil receiving surface 238a and the second coil receiving surface 238b, as in the first embodiment described above. However, in this embodiment, there is no step in the relief recess 238c. Thus, in this embodiment, the bending angle of the drive coil 222b, which is positioned in the middle, is the largest, but since there is no step in the relief recess 238c, the ends of the drive coils 222b and 222c can be received in the relief recess 238c.

[0062] Figure 8 is an exploded perspective view of a multiphase linear motor according to a fourth embodiment of the present invention. As shown in Figure 8, the multiphase linear motor 300 according to the fourth embodiment of the present invention includes a magnetic circuit 20 and a coil assembly 322 disposed within the air gap of the magnetic circuit 20. In this embodiment as well, a magnetic sensor and a flexible substrate are attached to the upper surface of the coil assembly 322, but they are omitted from the illustration in Figure 8.

[0063] In this embodiment, the coil assembly 322 is composed of two drive coils 322a and 322b. In this embodiment, the two drive coils are arranged in combination in the order of drive coil 322a, 322b, from the side closest to the image sensor surface 4a.

[0064] Furthermore, in this embodiment, the ends of the drive coil 322a, which is positioned closer to the image sensor surface 4a, are not bent but extend in a straight line. The drive coil 322b, which is positioned on the object side, has both ends bent and is positioned below the drive coil 322a.

[0065] On the other hand, as shown in Figure 8, coil support portions 318a are provided at the upper end of each lens frame 18. These coil support portions 318a are provided on both sides of the lens frame 18 so as to be located on both sides of the yoke of the magnetic circuit 20. Furthermore, each coil support portion 318a supports both ends of each drive coil 322a and 322b outside the air gap 34 of the magnetic circuit 20.

[0066] Furthermore, the upper part of each coil support portion 318a is provided with a first coil receiving surface 338a that contacts only the driving coil 322a of the two driving coils, and a second coil receiving surface 338b that contacts both driving coils 322a and 322b. In this embodiment as well, the first coil receiving surface 338a, which extends in a direction perpendicular to the optical axis A, is provided on the side of the coil support portion 318a closest to the image sensor surface 4a.

[0067] Furthermore, each coil support portion 318a is provided with a relief recess 338c for receiving the ends of the drive coil 322b, which have both ends bent. The relief recess 338c is a recess that is lower than the first coil receiving surface 338a and the second coil receiving surface 338b, as in the first embodiment described above. However, in this embodiment, there is no step in the relief recess 338c. Thus, in this embodiment, the ends of the drive coil 322b are received in the relief recess 238c, which does not have a step.

[0068] Figure 9 is an exploded perspective view of a multiphase linear motor according to a fifth embodiment of the present invention. As shown in Figure 9, the multiphase linear motor 400 according to the fifth embodiment of the present invention includes a magnetic circuit 20 and a coil assembly 422 disposed within the air gap of the magnetic circuit 20. In this embodiment as well, a magnetic sensor and a flexible substrate are attached to the upper surface of the coil assembly 422, but they are omitted from the illustration in Figure 9.

[0069] In this embodiment, the coil assembly 422 is composed of four drive coils 422a, 422b, 422c, and 422d. In this embodiment, the four drive coils are arranged in combination in the order of drive coils 422a, 422b, 422c, and 422d, starting from the side closest to the image sensor surface 4a.

[0070] Furthermore, in this embodiment, the ends of the drive coil 422a, which is positioned closest to the image sensor surface 4a, are not bent but extend in a straight line. The drive coil 422b, which is positioned second closest to the image sensor surface 4a, has both ends bent and is positioned below the drive coil 422a. The ends of the third drive coil 422c are also bent downwards and are positioned below the drive coil 422b. The drive coil 422d, which is positioned closest to the object, has the largest bend angle at both ends. Thus, in this embodiment, the bend angle at both ends of each drive coil increases sequentially toward the object.

[0071] On the other hand, as shown in Figure 9, coil support portions 418a are provided at the upper end of each lens frame 18. These coil support portions 418a are provided on both sides of the lens frame 18 so as to be located on both sides of the yoke of the magnetic circuit 20. Furthermore, each coil support portion 418a supports both ends of each drive coil 422a, 422b, 422c, and 422d outside the air gap 34 of the magnetic circuit 20.

[0072] Furthermore, as in the first embodiment described above, the upper part of each coil support portion 418a is provided with a first coil receiving surface 438a that only the drive coil 422a of the four drive coils contacts, and a second coil receiving surface 438b that all four drive coils 422a, 422b, 422c, and 422d contact. In this embodiment as well, the first coil receiving surface 438a extending in a direction perpendicular to the optical axis A is provided on the side of the coil support portion 418a closest to the image sensor surface 4a.

[0073] Furthermore, each coil support portion 418a is provided with a relief recess 438c that receives the ends of the drive coils 422b, 422c, and 422d, whose ends are bent. The relief recess 438c is a recess that is lower than the first coil receiving surface 438a and the second coil receiving surface 438b, as in the first embodiment described above. However, in this embodiment, two stepped portions 438d and 438e are provided in the relief recess 438c. Thus, in this embodiment, four drive coils are provided, with the stepped portion 438d provided along the second drive coil 422b, and the stepped portion 438e provided along the third drive coil 422c.

[0074] In other words, in this embodiment, a stepped portion 438e is provided at a position higher than the bottom surface of the relief recess 438c, and a stepped portion 438d is provided at a position higher than the stepped portion 438e and lower than the first coil receiving surface 438a. Thus, the relief recess 438c is formed in a stepped shape to match the bending angle of each drive coil, and it becomes lower towards the side closer to the object. By configuring the coil support portion 418a in a stepped shape, when manufacturing the lens frame 18 by resin molding, it is possible to mold it with a mold without undercuts, thereby reducing manufacturing costs.

[0075] Next, the routing of the wires drawn from the coil assembly provided in the multiphase linear motor of the embodiment of the present invention will be described.

[0076] First, with reference to Figures 10 to 13, the routing of the wires drawn from the coil assembly 22 provided in the multiphase linear motor 10 of the first embodiment of the present invention will be described.

[0077] Figure 10 is a perspective view showing a coil assembly 22 taken out of a multiphase linear motor 10 according to the first embodiment of the present invention. The upper part shows the coil assembly 22 disassembled into three drive coils, and the lower part shows the coil assembly 22 formed by combining the three drive coils. Figure 11 is a perspective view showing a coil assembly 22 taken out of a multiphase linear motor 10 according to the first embodiment of the present invention, showing the connections of the conductors drawn out from each drive coil.

[0078] As shown in Figure 10, the coil assembly 22 provided in the multiphase linear motor 10 of the first embodiment of the present invention is composed of a combination of three drive coils: drive coil 22a, drive coil 22b, and drive coil 22c. As described above, these drive coils are, as a whole, elongated, flat coils wound in a roughly rectangular shape with rounded corners. Each drive coil consists of two straight sections that extend in a roughly straight line within the air gap 34 (Figure 5) of the magnetic circuit 20, and two ends that extend outside the air gap 34 to connect these straight sections, respectively.

[0079] Specifically, the drive coil 22a has two straight sections 22a1 and two ends 22a2 and 22a3 (both ends), the drive coil 22b has two straight sections 22b1 and two ends 22b2 and 22b3 (both ends), and the drive coil 22c has two straight sections 22c1 and two ends 22c2 and 22c3 (both ends). The two ends 22a2 and 22a3 of the first drive coil, the drive coil 22a, extend in the same plane as the straight section 22a1 and are not bent. On the other hand, the two ends 22b2 and 22b3 of the second drive coil, the drive coil 22b, are bent downwards so as not to interfere with the ends of the drive coil 22a.

[0080] Furthermore, the two ends 22c2 and 22c3 of the drive coil 22c are bent downward at a larger bending angle than the drive coil 22b so as not to interfere with the ends of the drive coil 22b. Here, in this specification, "second drive coil" means a drive coil whose bending angles at both ends are larger than those of the "first drive coil". Therefore, as described above, if drive coil 22a is the "first drive coil", then both drive coils 22b and 22c correspond to the "second drive coil". Also, if drive coil 22b is the "first drive coil", then drive coil 22c corresponds to the "second drive coil".

[0081] Furthermore, as shown in the lower part of Figure 10, the coil assembly 22 is constructed by arranging one straight section 22b1 of the drive coil 22b and one straight section 22c1 of the drive coil 22c between the two straight sections 22a1 of the drive coil 22a (see also Figure 5). This allows for a high-density arrangement of the straight sections of each drive coil. The ends on both sides of each drive coil assembled in this manner are supported by the coil support section 18a (Figures 2 and 3). That is, one surface of each drive coil (the lower surface in Figure 10) is positioned to abut against and bond to the second coil receiving surface 38b (Figure 3) of the coil support section 18a.

[0082] Furthermore, as shown in Figure 10, each drive coil 22a, 22b, and 22c is constructed by winding a thin wire many times. The wire of the drive coil is wound starting from the innermost circumference, forming multiple layers in the thickness direction of the drive coil, and winding multiple layers toward the outer circumference, ending at the outermost circumference. Specifically, in the drive coil 22a, one end 22a4 of the wire is wound starting from the innermost circumference of one end 22a3, and the other end 22a5 is wound ending at the outermost circumference of the end 22a3. Similarly, in the drive coil 22b, one end 22b4 of the wire is wound starting from the innermost circumference of the end 22b3, and the other end 22b5 is wound ending at the outermost circumference of the end 22b3. In the drive coil 22c, one end 22c4 of the wire is wound starting from the innermost circumference of the end 22c3, and the other end 22c5 is wound ending at the outermost circumference of the end 22c3.

[0083] Furthermore, one end 22a4, 22b4, and 22c4 of the conductors of each drive coil are wound starting from the innermost circumference of the drive coil, on the side that does not contact the second coil receiving surface 38b (the top surface in Figure 10). In other words, one end 22a4 of the conductor of drive coil 22a is drawn out from the innermost circumference of the side of the drive coil that does not contact the second coil receiving surface 38b, and from one of the two ends 22a3. Similarly, the end 22b4 of the conductor of drive coil 22b is drawn out from the innermost circumference of the side that does not contact the second coil receiving surface 38b, and from one of the ends 22b3, and the end 22c4 of the conductor of drive coil 22c is drawn out from the innermost circumference of the side that does not contact the second coil receiving surface 38b, and from one of the ends 22c3.

[0084] Furthermore, in this embodiment, the end 22a4 of the wire drawn from the innermost circumference of the drive coil 22a is drawn out to the side where the drive coil 22b is located. (Note that "the side where the drive coil 22b is located" means the side where the drive coil 22b protrudes from the inside of the drive coil 22a.) In this way, one end of the wire drawn from the innermost circumference of the first drive coil is drawn out to the side where the second drive coil (a drive coil with a larger bending angle at both ends than the first drive coil) is located.

[0085] Furthermore, as shown in Figure 11, the starting and ending wires of each drive coil 22a, 22b, and 22c are electrically connected to each other. That is, in the example shown in Figure 11, the starting end 22a4 of drive coil 22a, the ending end 22b5 of drive coil 22b, and the starting end 22c4 of drive coil 22c are electrically connected to each other, forming a connection portion 23. In the example shown in Figure 11, the connection portion 23 is formed by twisting the ends of each wire together and soldering them to create a single wire.

[0086] On the other hand, the other ends of the conductors of each drive coil 22a, 22b, and 22c are led out toward the rear (towards the image side of the imaging device 1 (Figure 1), and the upper right of Figure 11). That is, in the example shown in Figure 11, the winding end 22a5 of drive coil 22a, the winding start end 22b4 of drive coil 22b, and the winding end 22c5 of drive coil 22c are led out toward the rear. In this embodiment, nothing is connected to the connection part 23, but when each drive coil 22a, 22b, and 22c is connected in a Y-connection (star connection), the connection part 23 can be connected to the neutral point (not shown) of the electrical circuit. In this case, a voltage is applied to the ends 22a5, 22b4, and 22c5 of each Y-connected drive coil at predetermined timings to allow current to flow through each drive coil.

[0087] Furthermore, in the example shown in Figure 11, the connection portion 23, which connects the ends of the wires of each drive coil, is located on the outside of the drive coil 22a (first drive coil) and, in a top view (viewed from a direction perpendicular to the plane on which each drive coil is arranged), overlaps with the drive coils 22b and 22c (second drive coils). That is, the connection portion 23 is positioned in the space created to the side of the drive coil 22a by bending the ends 22b3 and 22c3 of the drive coils 22b and 22c downwards. This makes it possible to effectively utilize the empty space in the coil assembly 22 and to miniaturize the coil assembly 22.

[0088] Next, with reference to Figures 12 and 13, a modified example of the routing of the wires drawn out from the coil assembly 22 provided in the multiphase linear motor 10 of the first embodiment of the present invention will be described.

[0089] Figure 12 is a perspective view showing the coil assembly 22 removed from the multiphase linear motor 10 of the first embodiment of the present invention. The upper part shows the coil assembly 22 disassembled into three drive coils, and the lower part shows the coil assembly 22 formed by combining the three drive coils. Figure 13 is a perspective view showing the coil assembly 22 removed from the multiphase linear motor 10 of the first embodiment of the present invention, showing the connections of the conductors drawn from each drive coil.

[0090] First, in the examples shown in Figures 10 and 11, the starting end 22a4 and ending end 22a5 of the drive coil 22a were each drawn out from one end 22a3 of the drive coil 22a, the starting end 22b4 and ending end 22b5 of the drive coil 22b were each drawn out from one end 22b3 of the drive coil 22b, and the starting end 22c4 and ending end 22c5 of the drive coil 22c were each drawn out from one end 22c3 of the drive coil 22c.

[0091] In contrast, in the examples shown in Figures 12 and 13, the starting and ending ends of the wires of each drive coil are drawn out from separate ends of each drive coil. Specifically, in this example, the starting end 22a4 of the drive coil 22a is drawn out from one end 22a2, while the ending end 22a5 is drawn out from the other end 22a3. Similarly, the starting end 22b4 of the drive coil 22b is drawn out from one end 22b3, while the ending end 22b5 is drawn out from the other end 22b2. Furthermore, the starting end 22c4 of the drive coil 22c is drawn out from one end 22c2, while the ending end 22c5 is drawn out from the other end 22c3.

[0092] Furthermore, in the examples shown in Figures 12 and 13, the starting and ending wires of the drive coil 22a are led out to the side where the drive coil 22b is located, and the starting and ending wires of the drive coil 22b are led out to the side where the drive coil 22c is located. Thus, in the examples shown in Figures 12 and 13, the starting and ending wires of the first drive coil are led out to the side where the second drive coil is located.

[0093] Furthermore, as shown in Figure 13, the end 22a4 of the starting wire of the drive coil 22a, the end 22b5 of the ending wire of the drive coil 22b, and the end 22c4 of the starting wire of the drive coil 22c are electrically connected to each other, forming a connection portion 23. In the example shown in Figure 13, the connection portion 23 is formed by twisting the ends of each wire together and soldering them to create a single wire.

[0094] Furthermore, in the example shown in Figure 13, the connection portion 23, which connects the ends of the wires of each drive coil, is located on the outside of the drive coil 22a (first drive coil) and, in a top view, overlaps with the drive coils 22b and 22c (second drive coils). That is, the connection portion 23 is positioned in the space created to the side of the drive coil 22a by bending the ends 22b2 and 22c2 of the drive coils 22b and 22c downwards. This makes it possible to effectively utilize the empty space in the coil assembly 22 and to miniaturize the coil assembly 22.

[0095] Next, with reference to Figures 14 to 18, the routing of the wires drawn from the coil assembly 422 provided in the multiphase linear motor 400 of the fifth embodiment of the present invention will be described.

[0096] Figure 14 is a perspective view showing a coil assembly 422 taken out of the multiphase linear motor 400 of the fifth embodiment of the present invention. The left side shows the coil assembly 422 disassembled into four drive coils, and the right side shows the coil assembly 422 formed by combining the four drive coils. Figure 15 is a perspective view showing a coil assembly 422 taken out of the multiphase linear motor 400 of the fifth embodiment of the present invention, showing the connections of the conductors drawn out from each drive coil.

[0097] As shown in Figure 14, the coil assembly 422 provided in the multiphase linear motor 400 of the fifth embodiment of the present invention is composed of a combination of four drive coils: drive coil 422a, drive coil 422b, drive coil 422c, and drive coil 422d. As described above, these drive coils are, as a whole, elongated, flat coils wound in a roughly rectangular shape with rounded corners. Each drive coil consists of two straight sections that extend roughly in a straight line within the air gap of the magnetic circuit, and two ends that extend outside the air gap to connect these straight sections, respectively.

[0098] Specifically, the drive coil 422a has two straight sections 422a1 and two ends 422a2 and 422a3 (both ends), the drive coil 422b has two straight sections 422b1 and two ends 422b2 and 422b3 (both ends), the drive coil 422c has two straight sections 422c1 and two ends 422c2 and 422c3 (both ends), and the drive coil 422d has two straight sections 422d1 and two ends 422d2 and 422d3 (both ends). The two ends 422a2 and 422a3 of the first drive coil, drive coil 422a, extend on the same plane as the straight section 422a1 and are not bent. On the other hand, the two ends 422b2 and 422b3 of the second drive coil, drive coil 422b, are bent downwards so as not to interfere with the ends of drive coil 22a.

[0099] Furthermore, the two ends 422c2 and 422c3 of the drive coil 422c are bent downward at a larger angle than the drive coil 22b so as not to interfere with the ends of the drive coil 422b. Similarly, the two ends 422d2 and 422d3 of the drive coil 422d are bent downward at a larger angle than the drive coil 22c so as not to interfere with the ends of the drive coil 422c.

[0100] Furthermore, as shown on the right side of Figure 14, the coil assembly 422 is constructed by arranging one straight section of each drive coil 422b, 422c, and 422d between the two straight sections 422a1 of the drive coil 422a. This allows for a high-density arrangement of the straight sections of each drive coil. The ends on both sides of each drive coil assembled in this manner are supported by coil support sections. That is, one surface of each drive coil (the lower surface in Figure 14) is positioned and bonded to the second coil receiving surface of the coil support section.

[0101] Furthermore, as shown in Figure 14, each drive coil 422a, 422b, and 422c is constructed by winding a thin wire many times. Specifically, in the drive coil 422a, one end 422a4 of the wire is started winding from the innermost circumference of one end 422a3, and the other end 422a5 is finished winding from the outermost circumference of the other end 22a3. Similarly, in the drive coil 422b, one end 422b4 of the conductor is wound starting from the innermost circumference of end 422b3 and the other end 422b5 is wound ending at the outermost circumference of end 422b3; in the drive coil 422c, one end 422c4 of the conductor is wound starting from the innermost circumference of end 422c3 and the other end 422c5 is wound ending at the outermost circumference of end 422c3; and in the drive coil 422d, one end 422d4 of the conductor is wound starting from the innermost circumference of end 422d3 and the other end 422d5 is wound ending at the outermost circumference of end 422d3.

[0102] Furthermore, one end 422a4, 422b4, 422c4, and 422d4 of the conductors of each drive coil are wound starting from the innermost circumference of the drive coil, on the side that does not contact the second coil receiving surface (the top surface in Figure 14). In other words, one end 422a4 of the conductor of the drive coil 422a is drawn out from the innermost circumference of the side of the drive coil that does not contact the second coil receiving surface, and from one of the two ends 422a3. Similarly, the starting end of the conductor of each drive coil is drawn out from the innermost circumference of the side that does not contact the second coil receiving surface, and from one of the ends.

[0103] Furthermore, in this embodiment, the end 422a4 of the wire drawn from the innermost circumference of the drive coil 422a is drawn out on the side where the drive coil 422b is located. Thus, in the example shown in Figure 14, one end of the wire drawn from the innermost circumference of the first drive coil is drawn out on the side where the second drive coil (a drive coil with a larger bending angle at both ends than the first drive coil) is located.

[0104] Furthermore, as shown in Figure 15, the starting and ending wires of each drive coil 422a, 422b, 422c, and 422d are electrically connected to each other. That is, in the example shown in Figure 15, the starting end 422a4 of drive coil 422a and the ending end 422c5 of drive coil 422c are electrically connected to each other, forming a connection part 423a. Similarly, the starting end 422b4 of drive coil 422b and the ending end 422d5 of drive coil 422d are electrically connected to each other, forming a connection part 423b. In the example shown in Figure 15, the connections parts 423a and 423b are formed by twisting the ends of each wire together and soldering them to create a single wire.

[0105] On the other hand, the other ends of the wires of each drive coil 422a, 422b, 422c, and 422d are drawn out towards the rear (upper right in Figure 15). This allows a voltage to be applied at predetermined timings between the ends 422a5 and 422c4 of the wires drawn out from the drive coils, and between the ends 422b5 and 422d4 of the wires, respectively, to supply drive current to each drive coil.

[0106] Furthermore, in the example shown in Figure 15, the connecting parts 423a and 423b, which connect the ends of the wires of each drive coil, are located on the outside of the drive coil 422a (first drive coil) and, in a top view (viewed from a direction perpendicular to the plane on which each drive coil is arranged), are positioned to overlap with the drive coils 422c and 422d (second drive coils). That is, the connecting parts 423a and 423b are positioned in the space created on the side of the drive coil 422a by bending the ends 422c3 and 422d3 of the drive coils 422c and 422d downwards. This makes it possible to effectively utilize the empty space in the coil assembly 422 and to miniaturize the coil assembly 422.

[0107] Next, with reference to Figures 16 and 17, a modified example of the routing of the wires drawn from the coil assembly in the multiphase linear motor 400 of the fifth embodiment of the present invention will be described.

[0108] Figure 16 is a perspective view showing a coil assembly 422 taken out of the multiphase linear motor 400 of the fifth embodiment of the present invention. The left side shows the coil assembly 422 disassembled into four drive coils, and the right side shows the coil assembly 422 formed by combining the four drive coils. Figure 17 is a perspective view showing a coil assembly 422 taken out of the multiphase linear motor 400 of the fifth embodiment of the present invention, showing the connections of the conductors drawn out from each drive coil.

[0109] In the modified examples shown in Figures 16 and 17, the coil assembly 422 is constructed by combining four drive coils, 422a to 422d. Furthermore, the ends of each drive coil are bent in the same manner as in the examples shown in Figures 14 and 15, thus combining the four drive coils.

[0110] In the examples shown in Figures 14 and 15, the starting and ending wires of each drive coil are drawn from the same end of each drive coil, and all the wires drawn from each drive coil are drawn from one side of the coil assembly 422. In contrast, in the modified examples shown in Figures 16 and 17, the starting and ending wires of each drive coil are drawn from different ends, and each wire is drawn from both sides of the coil assembly 422.

[0111] That is, as shown in Figure 16, the starting ends 422a4, 422b4 of the wires for the drive coils 422a and 422b, and the ending ends 422c5, 422d5 of the wires for the drive coils 422c and 422d are drawn out from one end of the coil assembly 422. The ending ends 422a5, 422b5 of the wires for the drive coils 422a and 422b, and the starting ends 422c4, 422d4 of the wires for the drive coils 422c and 422d are drawn out from the other end of the coil assembly 422.

[0112] Furthermore, in this modified example, as shown in Figure 17, the starting end 422a4 of the winding of the drive coil 422a and the ending end 422c5 of the winding

[0113] Furthermore, in the example shown in Figure 17, the connecting parts 423a and 423b, which connect the ends of the wires of each drive coil, are located on the outside of the drive coil 422a (first drive coil) and, in a top view (viewed from a direction perpendicular to the plane on which each drive coil is arranged), overlap with the drive coils 422c and 422d (second drive coils). That is, the connecting parts 423a and 423b are positioned in the space created on the side of the drive coil 422a by bending the ends 422c3 and 422d3 of the drive coils 422c and 422d downwards. This makes it possible to effectively utilize the empty space in the coil assembly 422 and to miniaturize the coil assembly 422.

[0114] Next, with reference to Figure 18, further variations in the routing of the conductors drawn from the coil assembly 422 in the multiphase linear motor 400 of the fifth embodiment of the present invention will be described.

[0115] In the example shown in Figure 18, the positions of the wires drawn from each drive coil are the same as in the modified examples shown in Figures 16 and 17. In the example shown in Figure 18, the starting end 422a4 of the wire of drive coil 422a and the ending end 422c5 of the wire of drive coil 422c, which are drawn from one end of the coil assembly 422, are connected to form a connection portion 423a. Furthermore, the ending end 422b5 of the wire of drive coil 422b and the starting end 422d4 of the wire of drive coil 422d, which are drawn from the other end of the coil assembly 422, are connected to form a connection portion 423b. Thus, in the modified example shown in Figure 18, two connection portions 423a and 423b are provided at both ends of the coil assembly 422, respectively.

[0116] Furthermore, in the example shown in Figure 18, the connection portion 423a, to which the ends of the drive coil wires are connected, is located on the outside of the drive coil 422a (first drive coil) and, in a top view, overlaps with the drive coil 422c (second drive coil). In addition, another connection portion 423b is located on the outside of the drive coils 422a to 422c (first drive coils) and, in a top view, overlaps with the drive coil 422d (second drive coil). Specifically, the connection portion 423a is positioned in the space formed to the side of the drive coil 422b by bending the end portion 422c2 of the drive coil 422c downwards. Similarly, the connection portion 423b is positioned in the space formed to the side of the drive coil 422c by bending the end portion 422d3 of the drive coil 422d downwards. This allows for effective use of the empty space in the coil assembly 422, making it possible to miniaturize the coil assembly 422.

[0117] Although embodiments of the present invention have been described above, various modifications can be made to the embodiments described above. In particular, in the embodiments described above, the focus lens was driven in the optical axis direction by a multiphase linear motor, but the multiphase linear motor of the present invention can also be applied to drive optical elements other than the focus lens or other components. Also, in the embodiments described above, one of the drive coils constituting the coil assembly was not bent, and the ends of the other drive coils were bent, but the ends of all drive coils may be bent. In this case, only the drive coil with the smallest bending angle at both ends will contact the first coil receiving surface.

[0118] (summary) A multiphase linear motor according to Embodiment 1 of the present invention is a multiphase linear motor that generates thrust in a predetermined driving direction, comprising: a magnetic circuit composed of a magnet and a yoke, which forms an air gap through which magnetic flux passes between a pair of opposing gap-forming surfaces; a coil assembly composed of a plurality of drive coils through which drive current flows, which is arranged between a pair of gap-forming surfaces of the magnetic circuit; and a movable part to which the coil assembly is attached and slidably supported so that the coil assembly can move in a predetermined driving direction within the air gap of the magnetic circuit, wherein the coil assembly comprises a plurality of flat drive coils, and these drive coils are one drive coil The linear sections of the other drive coils are arranged between the linear sections of the other drive coils, and at least one of the drive coils has both ends bent in a predetermined direction outside the air gap of the magnetic circuit so as not to interfere with the other drive coils that are combined with it. The movable part is provided with coil support parts that support both ends of each drive coil outside the air gap of the magnetic circuit, and the coil support parts are provided with a first coil receiving surface that contacts only drive coils whose ends are not bent, or drive coils whose ends have the smallest bending angle, and a second coil receiving surface that contacts all of the drive coils.

[0119] This configuration provides multiple flat drive coils, with the straight sections of other drive coils positioned between the straight sections of one drive coil. This allows for efficient arrangement of multiple drive coils within a narrow space, enabling the generation of large thrust with a compact linear motor. Furthermore, this configuration allows for a compact arrangement of the drive coils because both ends of the drive coils are bent in a predetermined direction outside the air gap of the magnetic circuit.

[0120] Furthermore, according to the above configuration, the movable part is provided with coil support parts that support both ends of each drive coil. These coil support parts include a first coil receiving surface that contacts only the drive coils whose ends are not bent or whose bending angle is the smallest, and a second coil receiving surface that contacts all of the drive coils. As a result, the drive coils can be firmly fixed to the movable part in a narrow space, and the drive coils can be accurately positioned within the air gap.

[0121] In the multiphase linear motor according to aspect 2 of the present invention, in aspect 1, the coil support portion of the movable part is provided with relief recesses for receiving drive coils whose ends are bent.

[0122] With this configuration, the ends of the drive coil, which are bent at both ends, can be glued to the relief recess, thereby more firmly fixing the drive coil to the movable part.

[0123] In the multiphase linear motor according to embodiment 3 of the present invention, in embodiment 1 or 2, the coil assembly has a drive coil with both ends that are not bent, or a drive coil with the smallest bend angle at both ends, arranged at one end, and adjacent to this drive coil, drive coils are arranged in order of increasing bend angle, and the relief recess of the coil support portion is formed in a stepped shape to match the bend angle of the drive coil.

[0124] This configuration allows for the use of molds without undercuts when manufacturing movable parts by resin molding, thereby reducing manufacturing costs.

[0125] In the multiphase linear motor according to embodiment 4 of the present invention, in embodiments 1 to 3, one end of the conductor constituting each drive coil is drawn out from the innermost circumference of the side of the drive coil that does not contact the second coil receiving surface, and from one of the ends.

[0126] With this configuration, one end of the conductor is drawn out from one end of the drive coil, at the innermost circumference of the side of the drive coil that does not contact the second coil receiving surface. This allows the conductor drawn out from the drive coil to be routed without interfering with other drive coils, thus enabling miniaturization of the coil assembly.

[0127] A multiphase linear motor according to aspect 5 of the present invention, in aspects 1 to 4, comprises a plurality of drive coils including a first drive coil and a second drive coil having a larger bending angle at both ends than the first drive coil, the coil assembly is constructed by arranging one straight section of the second drive coil between two straight sections of the first drive coil, and one end of the conductor drawn out from the innermost circumference of the first drive coil, which constitutes the first drive coil, is drawn out on the side where the second drive coil is located.

[0128] With this configuration, one end of the conductor that forms the first drive coil and is drawn out from the innermost circumference is drawn out to the side where the second drive coil is located. As a result, the conductor can be drawn out into the space created by bending both ends of the second drive coil more than the first drive coil, and the coil assembly can be made smaller.

[0129] In the multiphase linear motor according to embodiment 6 of the present invention, in embodiments 1 to 5, the plurality of drive coils include a first drive coil and a second drive coil having a larger bending angle at both ends than the first drive coil, and the coil assembly is constructed by arranging one straight section of the second drive coil between two straight sections of the first drive coil, and one end of the conductor constituting the first drive coil and one end of the conductor constituting the second drive coil are electrically connected outside the first drive coil and overlapping with the second drive coil.

[0130] With this configuration, one end of the conductor of the first drive coil and one end of the conductor of the second drive coil are electrically connected on the outside of the first drive coil and in a position overlapping with the second drive coil. As a result, the connection point of the conductors of the first and second drive coils can be placed in the space created by bending both ends of the second drive coil more than the first drive coil, thereby enabling miniaturization of the coil assembly.

[0131] Aspect 7 of the present invention is a lens unit for use attached to an imaging device, characterized by comprising a lens barrel and a multiphase linear motor according to any one of aspects 1 to 3 for moving at least one optical element disposed inside the lens barrel in a predetermined driving direction.

[0132] Aspect 8 of the present invention is an imaging device for capturing video or still images, characterized by comprising a lens unit as described in Aspect 4 and an imaging device body to which the lens unit is attached.

[0133] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0134] 1. Imaging device 2 Lens Units 4. Imaging device main unit 4a Image sensor surface 4b Release button 6 Lens barrel 8 lenses 10 Multiphase Linear Motors 12 Focus Ring 14. Autofocus Control Unit 16. Focusing lens (optical element) 18. Lens frame (movable part) 18a Coil support section 20 Magnetic Circuit 22 Coil Assembly 22a Drive coil 22a1 Straight section 22a2 end 22a3 end 22a4 edge 22a5 edge 22 and drive coil 22b1 Straight section 22b2 End 22b3 End 22b4 edge 22b5 edge 22c drive coil 22c1 Straight section 22c2 end 22c3 end 22c4 end 22c5 end 24 Hall sensors (magnetic sensors) 26 Guide poles 28 York 28a Plate 28b Plate 30 Magnets 30a permanent magnet 30b permanent magnet 32a Void forming surface 32b Void forming surface 34 Air gap 36 Flexible circuit board 38a First coil receiving surface 38b Second coil receiving surface 38c Recessed recess 38d stepped section 100 Multiphase Linear Motors 118a Coil support section 122 Coil Assembly 122a Drive coil 122b Drive coil 122c drive coil 138a First coil receiving surface 138b Second coil receiving surface 138c Recessed recess 138d Stepped section 200 Multiphase Linear Motor 218a Coil support section 222 Coil Assembly 222a Drive coil 222 and drive coil 222c drive coil 238a First coil receiving surface 238b Second coil receiving surface 238c Relief recess 400 Multiphase Linear Motor 418a Coil support section 422 Coil Assembly 422a Drive coil 422a1 Straight section 422a2 end 422a3 end 422a4 edge 422a5 edge 422b Drive coil 422b1 Straight section 422b2 End 422b3 End 422b4 edge 422b5 edge 422c drive coil 422c1 Straight section 422c2 end 422c3 End 422c4 end 422c5 end 422d Drive coil 422d1 Straight section 422d2 End 422d3 End 422d4 edge 422d5 edge 438a First coil receiving surface 438b Second coil receiving surface 438c Recessed recess 438d Stepped section 438e Stepped section

Claims

1. A multiphase linear motor that generates thrust in a predetermined driving direction, A magnetic circuit consisting of a magnet and a yoke, which forms an air gap through which magnetic flux passes between a pair of opposing gap-forming surfaces, A coil assembly comprising multiple drive coils through which a drive current flows, and positioned between the pair of gap-forming surfaces of the magnetic circuit, The coil assembly is mounted on a movable part that is slidably supported so that it can move in a predetermined driving direction within the air gap of the magnetic circuit, It has, The above coil assembly comprises a plurality of flat drive coils, which are combined such that the straight sections of other drive coils are positioned between the straight sections of one drive coil, and at least one of the drive coils has both ends bent in a predetermined direction outside the air gap of the magnetic circuit so as not to interfere with the other combined drive coils. The movable part is provided with coil support parts that support both ends of each drive coil outside the air gap of the magnetic circuit, and the coil support part is provided with a first coil receiving surface that contacts only drive coils whose ends are not bent, or drive coils with the smallest bending angle at both ends, and a second coil receiving surface that contacts all drive coils.

2. The multiphase linear motor according to claim 1, wherein the coil support portion of the movable part is provided with relief recesses for receiving drive coils whose ends are bent.

3. The multiphase linear motor according to claim 2, wherein the coil assembly has a drive coil with both ends not bent, or a drive coil with the smallest bend angle at both ends, positioned at one end, and adjacent to this drive coil, drive coils are arranged in order of increasing bend angle, and the relief recess of the coil support portion is formed in a stepped shape to match the bend angle of the drive coil.

4. The multiphase linear motor according to claim 1, wherein one end of the conductor constituting each of the above-mentioned drive coils is drawn out from the innermost circumference of the side of the drive coil that does not contact the second coil receiving surface, and from one of the two ends.

5. The multiphase linear motor according to claim 4, wherein the plurality of drive coils include a first drive coil and a second drive coil having a greater bending angle at both ends than the first drive coil, the coil assembly is constructed by arranging one straight section of the second drive coil between two straight sections of the first drive coil, and one end of the conductor drawn out from the innermost circumference of the first drive coil, which constitutes the first drive coil, is drawn out on the side where the second drive coil is located.

6. The plurality of drive coils include a first drive coil and a second drive coil having a greater bending angle at both ends than the first drive coil, the coil assembly is constructed by arranging one straight section of the second drive coil between two straight sections of the first drive coil, and one end of the conductor constituting the first drive coil and one end of the conductor constituting the second drive coil are electrically connected outside the first drive coil and overlapping with the second drive coil, as described in claim 4.

7. A lens unit used by attaching it to an imaging device, Lens barrel and A multiphase linear motor according to any one of claims 1 to 6 for moving at least one optical element disposed inside the lens barrel in a predetermined driving direction, A lens unit characterized by having the following features.

8. An imaging device for capturing video or still images, The lens unit according to claim 7, The main body of the imaging device to which this lens unit is attached, An imaging device characterized by having the following features.

Images