Linear actuator, interchangeable lens, and imaging apparatus

Abstract

A linear actuator provided with: a fixed rod including at least two magnets and at least one inner yoke, the magnets and the inner yoke being alternately coupled, and the magnets having magnetic poles of the same polarity coupled to both sides of the inner yoke; and a plurality of tubular movable coils through which the fixed rod is inserted, the plurality of movable coils being movable relative to the fixed rod in a coupling direction of the magnet and the inner yoke, and the plurality of movable coils being individually movable relative to the fixed rod.

Description

Technical Field

[0001] The present technology relates to the technical field of a linear actuator including a magnet and a movable coil and operated by energizing the movable coil, an interchangeable lens including the linear actuator, and an imaging device including the linear actuator. Background Art

[0002] There is a linear actuator which includes a magnet and a movable coil and applies a driving force to a movable body by energizing the movable coil to move the movable body (for example, see Patent Document 1, Patent Document 2, and Patent Document 3).

[0003] Such a linear actuator is used in various electronic devices including, for example, interchangeable lenses, imaging devices, etc. In the interchangeable lenses, imaging devices, etc., for example, a movable lens used as a zoom lens or a focus lens and a lens holder holding the movable lens are provided as a movable body, and zooming, focusing, etc. are performed by moving the movable lens in the optical axis direction together with the lens holder by the driving force of the linear actuator.

[0004] In Patent Document 1, magnets and iron are alternately coupled to form a movable rod, the movable rod is inserted into a coil held by a yoke, and the coil is energized to move the movable rod in the axial direction relative to the coil.

[0005] In Patent Document 2, magnets and iron are alternately coupled to form a fixed rod, the fixed rod is inserted into a movable coil held by a yoke, and the movable coil is energized to move the movable coil and the yoke together in the axial direction relative to the fixed rod.

[0006] In Patent Document 3, two movable bodies movable in the optical axis direction and two linear actuators for the respective movable bodies are provided, and the movable bodies are configured to be movable in the optical axis direction by the respective linear actuators.

[0007] Citation List

[0008] Patent Literature

[0009] Patent Document 1: Japanese Patent Application Publication No. 2016-86617

[0010] Patent Document 2: Japanese Patent Application Publication No. 2015-173580

[0011] Patent Document 3: Japanese Patent Application Publication No. 2006-178006 Summary of the invention

[0012] Problems to be solved by the present invention

[0013] Meanwhile, in recent years, in imaging devices and the like equipped with the above-described linear actuators, miniaturization is desired from the viewpoint of improving portability, and improvement in functionality is desired from the viewpoint of improving usability.

[0014] In order to improve such functionality, movable bodies such as a plurality of movable lenses are often provided inside an imaging device or the like. However, as the number of movable bodies increases, miniaturization may become difficult.

[0015] Therefore, an object of the linear actuator, interchangeable lens, and imaging device of the present technology is to ensure miniaturization while improving functionality.

[0016] Technical solutions to problems

[0017] The linear actuator according to the present technology includes: a fixed rod, including at least two magnets and at least one inner magnetic yoke, the magnets and the inner magnetic yoke are alternately coupled, and the magnets have magnetic poles of the same polarity coupled to both sides of the inner magnetic yoke; and a plurality of tubular movable coils, the fixed rod is inserted through the plurality of tubular movable coils, the plurality of movable coils can be moved relative to the fixed rod in the coupling direction of the magnets and the inner magnetic yoke, wherein the plurality of movable coils can be moved individually relative to the fixed rod.

[0018] As a result, each of the plurality of movable coils through which the fixed rod is inserted is energized so that each movable coil individually moves relative to the fixed rod.

[0019] The interchangeable lens according to the present technology includes: a movable body capable of moving in the direction of an optical axis; and a linear actuator, which moves the movable body in the direction of the optical axis, the linear actuator including: a fixed rod, including at least two magnets and at least one inner magnetic yoke, the magnets and the inner magnetic yoke being alternately coupled, and the magnets having magnetic poles of the same polarity coupled to both sides of the inner magnetic yoke; and a plurality of tubular movable coils, the fixed rod being inserted through the plurality of tubular movable coils, the plurality of movable coils being capable of moving relative to the fixed rod in the coupling direction of the magnets and the inner magnetic yoke, and the plurality of movable coils being capable of moving individually relative to the fixed rod.

[0020] As a result, in the linear actuator, each of the plurality of movable coils through which the fixed rod is inserted is energized so that each movable coil moves individually relative to the fixed rod.

[0021] According to the present technology, the imaging device includes: an imaging element, which converts an optical image into an electrical signal; a movable body capable of moving in the direction of an optical axis; and a linear actuator, which moves the movable body in the direction of the optical axis, the linear actuator including: a fixed rod, including at least two magnets and at least one inner magnetic yoke, the magnets and the inner magnetic yoke are alternately coupled, and the magnets have magnetic poles of the same polarity coupled to both sides of the inner magnetic yoke; and a plurality of tubular movable coils, the fixed rod is inserted through the plurality of tubular movable coils, the plurality of movable coils can move relative to the fixed rod in the coupling direction of the magnets and the inner magnetic yoke, and the plurality of movable coils can move individually relative to the fixed rod.

[0022] As a result, in the linear actuator, each of the plurality of movable coils through which the fixed rod is inserted is energized so that each movable coil moves individually relative to the fixed rod. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 and Figures 2 to 22 An embodiment of a linear actuator, an interchangeable lens, and an imaging device of the present technology are shown together, and is a perspective view showing the interchangeable lens and the imaging device.

[0024] Figure 2 is a perspective view showing the internal structure of the interchangeable lens, with a portion thereof cut away.

[0025] Figure 3 is a perspective view showing the internal structure of the interchangeable lens, in which a portion is cut away and the outer yoke is separated.

[0026] Figure 4 is along Figure 2 A cross-sectional view taken along line IV-IV.

[0027] Figure 5 is along Figure 2 A cross-sectional view taken along line VV of FIG.

[0028] Figure 6 is a front view showing the internal structure of the interchangeable lens.

[0029] Figure 7 is a perspective view of a linear actuator.

[0030] Figure 8 is a cross-sectional view of a linear actuator.

[0031] Fig. 9 is a conceptual diagram showing a magnetic flux generation state in a linear actuator.

[0032] Fig.10 is another conceptual diagram showing a magnetic flux generation state in a linear actuator.

[0033] Fig.11 is a conceptual diagram showing the state of magnetic flux generated from a magnet.

[0034] Fig.12 is a conceptual diagram showing forces generated in a magnet and an inner yoke.

[0035] Fig.13 is a perspective view showing a linear actuator having an outer yoke according to a first modification.

[0036] Fig.14 is a perspective view showing a linear actuator having an outer yoke according to a second modification.

[0037] Fig.15 is a perspective view showing a linear actuator having an outer yoke according to a third modification.

[0038] Fig.16 is a perspective view showing a linear actuator having an outer yoke according to a fourth modification.

[0039] Fig.17 is a perspective view showing a linear actuator having an outer yoke according to a fifth modification.

[0040] Fig.18 is a perspective view showing a linear actuator having an outer yoke according to a sixth modification.

[0041] Fig.19 is a perspective view showing a linear actuator having an outer yoke according to a seventh modification.

[0042] Fig. 20 : is a graph showing the magnitude of the magnetic attraction force with respect to the position on the fixed rod.

[0043] Fig.21 It is a graph showing the magnitude of the thrust on the fixed rod with respect to the position of the coil.

[0044] Fig. 22 is a block diagram of an imaging device. DETAILED DESCRIPTION

[0045] Hereinafter, embodiments for implementing the present technology will be described with reference to the drawings.

[0046] In the embodiments described below, the linear actuator of the present technology is applied to a linear actuator provided in an interchangeable lens that is attached to and detached from an imaging device that is a still camera. Note that the application scope of the present technology is not limited to the linear actuator provided in the interchangeable lens, and can also be applied to a linear actuator provided in an imaging device, and can also be applied to a linear actuator provided in various electronic devices other than the imaging device.

[0047] In the following description, it is assumed that the front, rear, up, down, left, and right directions are indicated as directions viewed from the photographer when an image is captured by an imaging device. Therefore, the subject side (object side) is the front, and the image plane side is the rear. Note that the front and back, up and down, and left and right directions below are for convenience of description, and the implementation of the present technology is not limited to these directions.

[0048] In addition, the lens group described below may include one or more lenses, or may include one or more lenses and other optical elements such as an aperture and a variable iris.

[0049] <Configuration of Imaging Device>

[0050] First, the configuration of the imaging device 100 to which the interchangeable lens 1 is attached and detached (see FIG. Figure 1 ).

[0051] The imaging device 100 is formed by arranging predetermined units inside and outside a housing 101. For example, a plurality of operation units 102 of various types are provided on the upper surface and the rear surface of the housing 101. As the operation unit 102, for example, a power button, a shutter button, a zoom knob, a mode switching knob, etc. are provided.

[0052] A display (display unit) (not shown) is provided on the rear surface of the housing 101 .

[0053] A circular opening 101a is formed in the front surface of the housing 101, and a mounting portion 103 for attaching the interchangeable lens 1 is provided in a portion around the opening 101a. The mounting portion 103 has an annular coupling ring 103a and a plurality of arc-shaped mounting engagement portions 103b protruding inwardly from the coupling ring 103a, and the plurality of mounting engagement portions 103b are provided to be spaced apart in the circumferential direction.

[0054] An imaging element 104 such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor) is provided inside the housing 101 and is located behind the opening 101 a .

[0055] The arc-shaped contact portion 105 is provided at a lower end portion within the mounting portion 103 .

[0056] <Interchangeable lens configuration>

[0057] Next, the configuration of the interchangeable lens 1 will be described (see Figures 1 to 8 ).

[0058] The interchangeable lens 1 is detachably attached to the imaging device 100 and includes a lens disposed on an outer barrel 2 (see Figure 1 ) of the internal and external predetermined units.

[0059] On the outer peripheral surface of the outer cylinder 2, for example, a plurality of adjustment rings 3 are rotatably supported in a state of being arranged in the front-rear direction. The adjustment rings 3 have functions such as performing focus adjustment, zoom adjustment, light amount adjustment of the iris, and the like.

[0060] Inside the outer barrel 2, a plurality of lenses included in the lens group 4 are arranged to be spaced apart in the optical axis direction (front-rear direction). The lens group 4 includes at least one lens, and a front lens 4a located at the frontmost side and another lens located at the rear side of the front lens 4a are provided in the outer barrel 2 as part of the lens group 4.

[0061] A lens mounting portion 5 is attached to the rear end portion of the outer barrel 2. The lens mounting portion 5 includes a plurality of engagement protrusions 5a protruding outward and spaced apart in the circumferential direction. A connection terminal (not shown) is provided on the rear end surface of the lens mounting portion 5.

[0062] The interchangeable lens 1 is attached to the imaging device 100 by coupling the lens mount 5 to the mount 103. The interchangeable lens 1 can be attached to the imaging device 100 by rotating the entire interchangeable lens 1 relative to the imaging device 100 about the optical axis.

[0063] In a state where the interchangeable lens 1 is attached to the imaging device 100, the connection terminal is connected to the contact portion 105 of the imaging device 100. Therefore, the interchangeable lens 1 and the imaging device 100 can exchange signals and power.

[0064] The interchangeable lens 1 can be detached from the imaging device 100 by rotating the entire interchangeable lens 1 about the optical axis relative to the imaging device 100 in a direction opposite to the direction when the interchangeable lens 1 is attached and moved away from the imaging device 100 .

[0065] The mechanism unit 6 is arranged inside the interchangeable lens 1 (see Figures 2 to 6 ). The mechanism unit 6 is formed by arranging or supporting a predetermined unit in the inner cylinder 7. Note that, in the interchangeable lens 1, the inner cylinder 7 may be provided integrally with the outer cylinder 2 as a part of the outer cylinder 2.

[0066] The inner cylinder 7 includes a non-magnetic material such as a resin material or a magnetic material, and includes a cylindrical main body portion 8 having an axial direction along the optical axis direction (front-rear direction) and an inner flange portion 9 protruding inward from one end portion of the main body portion 8 in the axial direction.

[0067] In the inner flange portion 9, two first bearing projections 10 are provided at positions spaced apart in the circumferential direction. In the inner flange portion 9, two second bearing projections 11 are provided at positions spaced apart in the circumferential direction, and the second bearing projections 11 are positioned spaced apart from the first bearing projections 10 in the circumferential direction.

[0068] Two holding recesses 12 are formed in the inner flange portion 9. The holding recess 12 is formed in a shape open to the front and is located between the first bearing protrusion 10 and the second bearing protrusion 11. The inner flange portion 9 is provided with yoke attachment portions (not shown) at positions on both sides of the holding recess 12 in the circumferential direction.

[0069] One end of the two first guide shafts 13 and one end of the two second guide shafts 14 are attached to the inner cylinder 7 (see Figures 2 to 4 ). The first guide shaft 13 has a rear end attached to the first bearing protrusion 10 and a front end attached to the first bearing (not shown). The second guide shaft 14 has a rear end attached to the second bearing protrusion 11 and a front end attached to the second bearing (not shown).

[0070] In the inner cylinder 7, a pair of linear actuators 15 are arranged on opposite sides across the central axis of the main body 8 (see Figures 2 to 6 ). The linear actuators 15 each include a fixed rod 16, a first movable coil 17, a second movable coil 18, and an outer yoke 19 (see Figure 7 and 8 ).

[0071] The fixing rod 16 includes a plurality of magnets 20 and a plurality of inner yokes 21, and the magnets 20 and the inner yokes 21 are linearly coupled alternately in the front-rear direction by, for example, bonding. The fixing rod 16 is formed to have, for example, a substantially rectangular cross-sectional shape in a direction orthogonal to the coupling direction of the magnets 20 and the inner yokes 21.

[0072] The magnet 20 has an N pole and an S pole magnetized in the coupling direction of the magnet 20 and the inner yoke 21 (see FIG. Figure 8 In the fixed rod 16, the magnetic poles of the same polarity of the magnets 20 adjacent via each inner yoke 21 are coupled to the inner yoke 21 located between the adjacent magnets 20, and the N poles and the N poles face each other via the inner yoke 21, or the S poles and the S poles face each other via the inner yoke 21.

[0073] The magnets 20 are each set so that the boundary 20a between the N pole and the S pole is at a predetermined position in the coupling direction. Therefore, regardless of the respective lengths of the magnet 20 and the inner yoke 21 in the coupling direction, the position of the boundary 20a is determined at a predetermined position.

[0074] The inner yoke 21 includes a magnetic material such as iron. For example, the inner yoke 21 is formed to have the same outer shape as that of the magnet 20 and to have a smaller size than that of the magnet 20 in the coupling direction.

[0075] The coupling parts 16a referred to as side yokes are provided at both ends of the fixing rod 16 in the coupling direction, and the coupling parts 16a are bonded by, for example, bonding (see Figure 7 and 8 ) is attached to the magnet 20. Similar to the inner yoke 21, the coupling member 16a also includes a magnetic material such as iron.

[0076] The first movable coil 17 and the second movable coil 18 are integrally formed into a substantially square cylindrical shape according to the shape of the fixing rod 16. One fixing rod 16 is inserted through the first movable coil 17 and the second movable coil 18 (see Figure 5 , 7 Note that the number of movable coils inserted into one fixed rod 16 is arbitrary as long as it is plural and the same number as the number of movable bodies described later is set. For example, in the case of setting three movable bodies, one fixed rod 16 is inserted into three movable coils.

[0077] The first movable coil 17 and the second movable coil 18 are each formed in a two-phase configuration, for example, and are configured so that the coil portion forming the first phase and the coil portion forming the second phase are arranged adjacent to each other. A predetermined gap through which the winding wire passes is formed between the coil portion forming the first phase and the coil portion forming the second phase, and the gap is filled with an adhesive to form each of the first movable coil 17 and the second movable coil 18.

[0078] When the first movable coil 17 is energized, a thrust related to the magnetic flux generated in the fixed rod 16 is generated in the first movable coil 17, and the first movable coil 17 moves in the coupling direction (optical axis direction) of the fixed rod 16 according to the direction in which the first movable coil 17 is energized. Therefore, in the linear actuator 15, the fixed rod 16 serves as a fixed portion, and the first movable coil 17 serves as a movable portion.

[0079] Furthermore, when the second movable coil 18 is energized, a thrust force related to the magnetic flux generated in the fixed rod 16 is generated in the second movable coil 18, and the second movable coil 18 moves in the coupling direction (optical axis direction) of the fixed rod 16 according to the energization direction of the second movable coil 18. Therefore, in the linear actuator 15, the second movable coil 18 also serves as a movable portion.

[0080] The outer yoke 19 includes a pair of facing portions 30 formed in a flat plate shape, which contains, for example, a magnetic material such as iron. The pair of facing portions 30 are located on opposite sides sandwiching the fixed rod 16, the first movable coil 17, and the second movable coil 18, and are arranged to cover the fixed rod 16, the first movable coil 17, and the second movable coil 18 from the outer peripheral side thereof. The length direction of the facing portion 30 is substantially the same as the length of the fixed rod 16 in the coupling direction.

[0081] In the linear actuator 15 configured as described above, the rear end portion of the fixing rod 16 is attached to the inner cylinder 7 (see Figure 2 , 3 and 5). The rear end portion of the fixing rod 16 is attached to the inner tube 7 by inserting a portion of one of the coupling parts 16a into the retaining recess 12 in the inner flange portion 9 and coupling the coupling part 16a to the inner flange portion 9 by screwing or the like. The other coupling part 16a of the fixing rod 16 is fixed to a fixing member (not shown).

[0082] A pair of facing portions 30 of the outer yoke 19 has rear end portions attached to yoke attaching portions provided in the inner flange portion 9 of the inner cylinder 7 and front end portions attached to an attaching member (not shown).

[0083] As described above, the outer yoke 19 is attached to the inner cylinder 7 and the attachment member, and thus serves as a fixed portion. Therefore, in the linear actuator 15, the fixed rod 16 and the outer yoke 19 serve as fixed portions, and the first movable coil 17 and the second movable coil 18 serve as movable portions.

[0084] On each first guide shaft 13, a first lens holder 22 and a lens 4b provided as a movable body are supported so as to be movable in the optical axis direction (see FIG. Figures 2 to 6 ). The lens 4b is a lens in the lens group 4, is held by the first lens holder 22, and functions as, for example, a focusing lens or a zoom lens.

[0085] The first lens holder 22 includes a frame-shaped lens holding portion 23, two supported portions 24 protruding in opposite directions from the lens holding portion 23 on the outer peripheral side, and two coil attachment portions 25 protruding in opposite directions from the lens holding portion 23 on the outer peripheral side. The supported portions 24 and the coil attachment portions 25 protrude from different positions in the circumferential direction of the lens holding portion 23.

[0086] The lens 4b is held by the lens holding portion 23. The lens 4b is attached to the lens holding portion 23 by bonding, press fitting, or the like.

[0087] The supported portion 24 is slidably supported by the first guide shaft 13. Therefore, the first lens holder 22 and the lens 4b are integrally guided by the first guide shaft 13 and move in the optical axis direction.

[0088] The first movable coil 17 is attached to the coil attachment portion 25 (see FIG. Figure 3 and 6 ). Therefore, when the first movable coil 17 is energized and the first movable coil 17 moves in the optical axis direction relative to the fixed rod 16, the first lens holder 22 and the lens 4b move in the optical axis direction together with the first movable coil 17, and the first movable coil 17, the lens 4b and the first lens holder 22 act as a movable body.

[0089] The second lens holder 26 and the lens 4c provided as a movable body are supported by the second guide shaft 14 so as to be movable in the optical axis direction (see FIG. Figures 2 to 5 ). The second lens holder 26 and the lens 4c are located behind the first lens holder 22 and the lens 4b. The lens 4c is a lens in the lens group 4, is held by the second lens holder 26, and functions as, for example, a focus lens or a zoom lens.

[0090] The second lens holder 26 includes a frame-shaped lens holding portion 27, two supported portions 28 protruding in opposite directions from the lens holding portion 27 on the outer peripheral side, and two coil attachment portions 29 protruding in opposite directions from the lens holding portion 27 on the outer peripheral side. The supported portions 28 and the coil attachment portions 29 protrude from different positions in the circumferential direction of the lens holding portion 27.

[0091] The lens 4c is held by the lens holding portion 27. The lens 4c is attached to the lens holding portion 27 by bonding, press fitting, or the like.

[0092] The supported portion 28 is slidably supported by the second guide shaft 14. Therefore, the second lens holder 26 and the lens 4c are integrally guided by the second guide shaft 14 and move in the optical axis direction.

[0093] The second movable coil 18 is attached to the coil attachment portion 29 (see Figure 3 ). Therefore, when the second movable coil 18 is energized and the second movable coil 18 moves in the optical axis direction relative to the fixed rod 16, the second lens holder 26 and the lens 4c move in the optical axis direction together with the second movable coil 18, and the second movable coil 18, the lens 4c and the second lens holder 26 serve as a movable body.

[0094] For example, by moving at least one of the lens 4 b or the lens 4 c in the optical axis direction, focusing or zooming is performed.

[0095] <Relationship between magnetic flux and movable coil, etc.>

[0096] Next, the relationship between the magnetic flux generated in the linear actuator 15 and the first movable coil 17 (the second movable coil 18), etc. will be described (see FIG. 1 ). Figures 9 to 12 ). Note that since the relationship between the magnetic flux and the first movable coil 17 and the relationship between the magnetic flux and the second movable coil 18 are the same, the relationship between the magnetic flux and the first movable coil 17 and the relationship between the magnetic flux and the second movable coil 18 will be described below as an example. In addition, Figures 9 to 11 1 is a conceptual diagram for easily describing the relationship and the like between the magnetic flux generated in the linear actuator 15 and the first movable coil 17 .

[0097] As described above, in the fixed rod 16 of the linear actuator 15, the magnets 20 and the inner yoke 21 are alternately coupled, in each magnet 20, the N pole and the S pole are magnetized in the coupling direction, and the N pole and the N pole, or the S pole and the S pole (which are the same poles of the magnets 20 adjacent through the inner yoke 21) are coupled to both surfaces of the inner yoke 21 (see Fig. 9 and 10 ).

[0098] Notice, Fig. 9 is an example showing a state in which the center of the first movable coil 17 in the axial direction is positioned to coincide with the center of the magnet 20 in the coupling direction, Fig.10 is an example showing a state in which the center of the first movable coil 17 in the axial direction is positioned to coincide with the center of the inner yoke 21 in the coupling direction.

[0099] A pair of facing portions 30 defining the outer yoke 19 are located in the vertical direction, and the direction in which the facing portion 30 does not exist is the left-right direction, in which the magnetic flux J generated in the magnet 20 passes from the N pole through the inner yoke 21, through the facing portion 30 of the outer yoke 19, and through the first movable coil 17 coupled to one surface of the magnet 20, and through the inner yoke 21 coupled to the other surface of the magnet 20 and again through the first movable coil 17 to reach the S pole (see Fig. 9 and 10 ). On the other hand, in the left-right direction, the magnetic flux J generated in the magnet 20 passes from the N pole through the inner yoke 21 coupled to one surface of the magnet 20 and through the first movable coil 17, and again passes through the inner yoke 21 coupled to the other surface of the magnet 20 and through the first movable coil 17 to reach the S pole.

[0100] Therefore, the magnetic flux J passes through the entire circumference of the first movable coil 17 (see Fig.11 ). Since the magnetic flux J passes through the entire circumference of the first movable coil 17 in this way, the magnetic flux J greatly contributes to the thrust of the first movable coil 17 to generate thrust over the entire circumference of the first movable coil 17, and high driving efficiency of the linear actuator 15 can be ensured.

[0101] In addition, since thrust is generated over the entire circumference of the first movable coil 17 and high driving efficiency in the linear actuator 15 can be ensured, sufficient driving force can be ensured even if the size of each unit in the linear actuator 15 is reduced, and the size and weight of the linear actuator 15 can be reduced.

[0102] In addition, since the magnetic flux J that has passed through the first movable coil 17 except for a part thereof passes through the two facing parts 30 located on the outer peripheral side of the first movable coil 17 and flows toward the S pole, the magnetic flux leakage is reduced through the outer magnetic yoke 19, and the thrust of the first movable coil 17 can be further improved.

[0103] On the other hand, in the linear actuator 15, the same magnetic poles of adjacent magnets 20 are coupled to the inner yoke 21 (see Fig.12 ). Therefore, a repulsive force P is generated between adjacent magnets 20, but in the linear actuator 15, since the inner yoke 21 is disposed between adjacent magnets 20, an attractive force Q is generated between the inner yoke 21 and the magnets 20, which reduces the repulsive force P generated between the magnets 20.

[0104] Furthermore, since the inner yoke 21 is disposed between the adjacent magnets 20 , the adjacent magnets 20 are disposed at a constant distance therebetween, which also reduces the repulsive force P generated between the magnets 20 .

[0105] Therefore, the difficulty of assembling the fixing rod 16 due to the repulsive force P generated when coupling the magnet 20 and the inner yoke 21 is reduced, and the fixing rod 16 having a configuration in which the same poles of adjacent magnets 20 are coupled to the inner yoke 21 can be assembled in an easy and stable state.

[0106] In the linear actuator 15, since the outer yoke 19 is disposed outside the fixed rod 16, the generation of leakage magnetic flux can be reduced as described above, but the presence of the outer yoke 19 generates a magnetic attraction force F between the outer yoke 19 and the fixed rod 16 (see Fig. 9 and 10 At this time, a load is generated in a direction in which the fixing rod 16 is attracted to the facing portion 30 by the magnetic attraction force F and deforms.

[0107] However, in the linear actuator 15 , the outer yoke 19 includes a pair of facing portions 30 located at opposite sides across the fixed rod 16 .

[0108] Therefore, an attractive force for attracting the fixing rod 16 in the opposite direction is generated by the facing portion 30 , which makes it possible to suppress deformation of the fixing rod 16 by hardly generating a force in a direction of bending the fixing rod 16 .

[0109] In addition, since the leakage magnetic flux is reduced by the pair of facing portions 30, the driving efficiency of the first movable coil 17 and the second movable coil 18 can be improved.

[0110] <Modification of Outer Yoke>

[0111] Next, a modification of the outer yoke will be described (see Figures 13 to 19 ). Note that the various modifications of the outer yoke described below (first to seventh modifications) can be used not only in the above-mentioned example in which a plurality of movable coils are movable relative to the fixed rod 16, but also in the example in which a single movable coil is movable relative to the fixed rod 16.

[0112] The outer yoke 19A according to the first modification is formed in a shape in which a plurality of working holes 40 are formed in the facing portion 30A (see Fig.13 The working hole 40 serves to reduce the magnetic flux density generated by the fixing rod 16 in the facing portion 30A.

[0113] The working holes 40 are positioned apart from each other in the coupling direction of the magnet 20 and the inner yoke 21, and are formed, for example, at positions corresponding to the inner yoke 21. The shape of the working hole 40 is, for example, circular, but may be other shapes such as rectangular. However, since the formation of the circular working hole 40 makes it difficult for stress to concentrate on the opening edge of the working hole 40, and the circular working hole 40 can be easily processed, the strength of the outer yoke 19A can be improved and the manufacturing cost can be reduced.

[0114] Since the formation of the working hole 40 in the facing portion 30A as described above reduces the magnetic flux density generated by the fixing rod 16 in the outer yoke 19A, the magnetic attraction of the outer yoke 19A relative to the fixing rod 16 is reduced, the deformation of the fixing rod 16 is effectively suppressed, and the reliability of the operation of the linear actuator 15 can be improved.

[0115] In addition, since the working hole 40 is formed at a position corresponding to the inner magnetic yoke 21, the working hole 40 is positioned to correspond to the portion with the highest magnetic flux density in the fixed rod 16, thereby enhancing the effect of reducing the magnetic attraction of the facing portion 30A relative to the fixed rod 16, and deformation of the fixed rod 16 can be more effectively prevented.

[0116] Note that according to the definition that the inner magnetic yokes 21 located at both ends of the fixing rod 16 are the end side inner magnetic yokes 21X, the size of the first working hole 40X formed at the position corresponding to the end side inner magnetic yoke 21X can be larger than the size of the second working hole 40Y formed at the position corresponding to the inner magnetic yoke 21 other than the end side inner magnetic yoke 21X.

[0117] Therefore, the configuration of the working hole 40 having different sizes depending on the position as described above reduces the thrust of the first movable coil 17 and the thrust of the second movable coil 18 at both ends of the fixed rod 16, and reduces the difference in thrust of the first movable coil 17 and the second movable coil 18 in the portion other than the two ends of the fixed rod 16, thereby ensuring the proper movement state of the first movable coil 17 and the second movable coil 18 relative to the fixed rod 16.

[0118] Although the example of the outer yoke 19A in which the working hole 40 is formed has been described above, as a second modification, an outer yoke 19B in which the working cutout 41 is formed instead of the working hole 40 may be configured (see Fig.14 The outer yoke 19B is formed into a shape in which a plurality of working cutouts 41 are formed in the facing portion 30B, and the working cutouts 41 serve to reduce the magnetic flux density generated in the facing portion 30B by the fixing rod 16 , similarly to the working holes 40 .

[0119] The working cutouts 41 are positioned apart from each other in the coupling direction of the magnet 20 and the inner yoke 21, and are formed on both sides of the facing portion 30B in the width direction at positions corresponding to the inner yoke 21, for example. The shape of the working cutout 41 is, for example, semicircular, but may be other shapes, such as rectangular. However, since the working cutout 41 is formed in a semicircular shape, stress is difficult to concentrate on the opening edge of the working cutout 41, and the semicircular working cutout 41 can be easily processed, so that the strength of the outer yoke 19B can be improved, and the manufacturing cost can be reduced.

[0120] Since the magnetic flux density generated by the fixing rod 16 in the outer yoke 19B is reduced by forming the working cutout 41 in the facing portion 30B as described above, the magnetic attraction of the outer yoke 19B to the fixing rod 16 is reduced, effectively suppressing the deformation of the fixing rod 16 and improving the reliability of the operation of the linear actuator 15.

[0121] In addition, since a working cut 41 is formed at a position corresponding to the inner magnetic yoke 21, the working cut 41 is located at a position corresponding to the portion with the highest magnetic flux density in the fixing rod 16, thereby enhancing the effect of reducing the magnetic flux density generated by the fixing rod 16 in the facing portion 30B, and being able to more effectively prevent deformation of the fixing rod 16.

[0122] In addition, similar to the outer yoke 19A, the outer yoke 19B can be configured so that the size of the first working cut 41X formed at the position corresponding to the end side inner yoke 21X is larger than the size of the second working cut 41Y formed at the position corresponding to the inner yoke 21 other than the end side inner yoke 21X.

[0123] The above configuration reduces the thrust of the first movable coil 17 and the thrust of the second movable coil 18 at the two ends of the fixed rod 16, and reduces the thrust difference between the first movable coil 17 and the second movable coil 18 in the part other than the two ends of the fixed rod 16, thereby ensuring the proper movement state of the first movable coil 17 and the second movable coil 18 relative to the fixed rod 16.

[0124] The outer yoke 19C according to the third modification example includes, in addition to the pair of facing portions 30, a coupling portion 42 (see Fig.15 ). In the outer yoke 19C, the pair of facing portions 30 and the coupling portion 42 are both formed to have a flat plate shape, and the pair of facing portions 30 and the coupling portion 42 are integrally formed.

[0125] In the case of using the outer yoke 19C, the fixed rod 16 is covered by the outer yoke 19C from three sides of the outer peripheral side. Therefore, the generation of leakage magnetic flux can be effectively suppressed, and the thrust of the first movable coil 17 and the second movable coil 18 can be improved.

[0126] In addition, since the pair of facing portions 30 and the coupling portion 42 are integrally formed, the thrust can be improved without increasing the number of components.

[0127] The outer yoke 19D according to the fourth modification is formed in a shape in which a plurality of working holes 40 are formed in the coupling portion 42D (see Fig.16 The working hole 40 is used to reduce the magnetic flux density generated by the fixing rod 16 in the coupling portion 42D.

[0128] The working holes 40 are positioned apart from each other in the coupling direction of the magnet 20 and the inner yoke 21, and are formed, for example, at positions corresponding to the inner yoke 21. The shape of the working hole 40 is, for example, circular, but may be other shapes such as rectangular. However, since the formation of the circular working hole 40 makes it difficult for stress to concentrate at the opening edge of the working hole 40, and the circular working hole 40 can be easily processed, the strength of the outer yoke 19D can be improved and the manufacturing cost can be reduced.

[0129] Since the formation of the working hole 40 in the coupling portion 42D as described above reduces the magnetic flux density generated by the fixing rod 16 in the outer yoke 19D, the magnetic attraction of the outer yoke 19D relative to the fixing rod 16 is reduced, the deformation of the fixing rod 16 is effectively suppressed, and the reliability of the operation of the linear actuator 15 can be improved.

[0130] In addition, since the working hole 40 is formed at a position corresponding to the inner magnetic yoke 21, the working hole 40 is positioned to correspond to the portion with the highest magnetic flux density in the fixed rod 16, thereby enhancing the effect of reducing the magnetic attraction of the coupling portion 42D relative to the fixed rod 16, and can more effectively prevent deformation of the fixed rod 16.

[0131] Furthermore, similar to the outer yoke 19A, the outer yoke 19D may be configured such that the size of the first working hole 40X formed at a position corresponding to the end side inner yoke 21X is larger than the size of the second working hole 40Y formed at a position corresponding to the inner yoke 21 other than the end side inner yoke 21X.

[0132] The above configuration reduces the thrust of the first movable coil 17 and the thrust of the second movable coil 18 at the two ends of the fixed rod 16, and reduces the thrust difference between the first movable coil 17 and the second movable coil 18 in the part other than the two ends of the fixed rod 16, thereby ensuring the proper movement state of the first movable coil 17 and the second movable coil 18 relative to the fixed rod 16.

[0133] Although the example of the outer yoke 19D in which the working hole 40 is formed has been described above, as a fifth modification, an outer yoke 19E in which the working hole 43 is formed instead of the working hole 40 may be configured (see Fig.17 ). The outer yoke 19E is formed in a shape in which a plurality of working holes 43 are formed in the coupling portion 42E, and the working holes 43 serve to reduce the magnetic flux density generated in the outer yoke 19E by the fixing rod 16 .

[0134] Note that, in the outer yoke 19E, the working hole 43 may be formed at a position from the coupling portion 42E to the facing portion 30 .

[0135] The working holes 43 are separated from each other in the coupling direction of the magnet 20 and the inner yoke 21 and are formed at positions corresponding to the inner yoke 21 in the width direction on both sides of the coupling portion 42E, for example. The shape of the working holes 43 is, for example, rectangular.

[0136] The coupling portion 42E includes a partition 42 a provided at a central portion in the width direction and extending in the coupling direction of the magnet 20 and the inner yoke 21 , the partition 42 a partitioning the two working holes 43 aligned in the width direction.

[0137] Since the outer yoke 19E includes the spacer 42a at the central portion in the width direction as described above, the spacer 42a has a function of reinforcing the coupling portion 42E, and high strength of the outer yoke 19E is ensured by the spacer 42a.

[0138] Since the formation of the working hole 43 in the coupling portion 42E as described above reduces the magnetic flux density generated by the fixing rod 16 in the outer yoke 19E, the magnetic attraction of the outer yoke 19E relative to the fixing rod 16 is reduced, the deformation of the fixing rod 16 is effectively suppressed, and the reliability of the operation of the linear actuator 15 can be improved.

[0139] In addition, since the working hole 43 is formed at a position corresponding to the inner magnetic yoke 21, the working hole 43 is located at a position corresponding to the portion with the highest magnetic flux density in the fixed rod 16, thereby enhancing the effect of reducing the magnetic attraction of the coupling part 42E relative to the fixed rod 16, and can more effectively prevent deformation of the fixed rod 16.

[0140] Furthermore, similar to the outer yoke 19D, the outer yoke 19E may be configured such that the size of the first working hole 43X formed at a position corresponding to the end side inner yoke 21X is larger than the size of the second working hole 43Y formed at a position corresponding to the inner yoke 21 other than the end side inner yoke 21X.

[0141] The above configuration reduces the thrust of the first movable coil 17 and the thrust of the second movable coil 18 at the two ends of the fixed rod 16, and reduces the thrust difference between the first movable coil 17 and the second movable coil 18 in the part other than the two ends of the fixed rod 16, thereby ensuring the proper movement state of the first movable coil 17 and the second movable coil 18 relative to the fixed rod 16.

[0142] Furthermore, although the example of the outer yoke 19D in which the working hole 40 is formed has been described above, as a sixth modification, an outer yoke 19F in which the working hole 44 is formed instead of the working hole 40 may be configured (see Fig.18 ). The outer yoke 19F is formed into a shape in which a plurality of working holes 44 are formed in the coupling portion 42F, and the working holes 44 serve to reduce the magnetic flux density generated in the outer yoke 19F by the fixing rod 16 .

[0143] Note that, in the outer yoke 19F, the working hole 44 may be formed at a position from the coupling portion 42F to the facing portion 30 .

[0144] The working holes 44 are located apart from each other in the coupling direction of the magnet 20 and the inner yoke 21 , and are formed in a slit shape.

[0145] As described above, forming the slit-shaped working holes 44 in the outer yoke 19F reduces the opening area of ​​each working hole 44 in the coupling portion 42F, ensuring high strength of the outer yoke 19F.

[0146] Since the working hole 44 is formed in the coupling portion 42F as described above, the magnetic flux density generated by the fixing rod 16 in the outer yoke 19F is reduced, the magnetic attraction force of the outer yoke 19F relative to the fixing rod 16 is reduced, the deformation of the fixing rod 16 is effectively suppressed, and the operational reliability of the linear actuator 15 can be improved.

[0147] In addition, since the working hole 44 is formed at a position corresponding to the inner magnetic yoke 21, the working hole 44 is located at a position corresponding to the portion with the highest magnetic flux density in the fixing rod 16, thereby enhancing the effect of reducing the magnetic flux density generated by the fixing rod 16 in the coupling portion 42F, and being able to more effectively prevent deformation of the fixing rod 16.

[0148] Furthermore, the outer yoke 19F may be configured such that the number of the working holes 44 formed at the positions corresponding to the end-side inner yoke 21X is greater than the number of the working holes 44 formed at the positions corresponding to the inner yoke 21 other than the end-side inner yoke 21X. Specifically, for example, three working holes 44 may be formed at the positions corresponding to the end-side inner yoke 21X, and for example, two working holes 44 may be formed at the positions corresponding to the inner yoke 21 other than the end-side inner yoke 21X.

[0149] The above configuration reduces the thrust of the first movable coil 17 and the thrust of the second movable coil 18 at the two ends of the fixed rod 16, and reduces the thrust difference between the first movable coil 17 and the second movable coil 18 in the part other than the two ends of the fixed rod 16, thereby ensuring the proper movement state of the first movable coil 17 and the second movable coil 18 relative to the fixed rod 16.

[0150] The outer yoke 19G according to the seventh modification is an example in which the thicknesses of the magnet 20 and the inner yoke 21 are changed in the coupling direction (see Fig.19 ).

[0151] The outer yoke 19G includes, for example, portions on both end sides in the coupling direction as thin portions 19a, and portions between the thin portions 19a as general portions 19b. The thickness of the thin portion 19a is smaller than the thickness of the general portion 19b. Note that the general portion 19b may have a configuration in which a plurality of layers are stacked in the thickness direction.

[0152] Since the thin portion 19a set as described above reduces the magnetic flux density generated by the fixing rod 16 in the thin portion 19a compared to the magnetic flux density generated in the general portion 19b, thereby reducing the magnetic attraction force of the outer yoke 19G relative to the fixing rod 16, the deformation of the fixing rod 16 is effectively suppressed, and the operational reliability of the linear actuator 15 can be improved.

[0153] Furthermore, the outer yoke 19G may be configured such that the thin portion 19 a is positioned corresponding to the end-side inner yoke 21X, and the general portion 19 b is provided corresponding to the inner yoke 21 other than the end-side inner yoke 21X.

[0154] The above configuration reduces the thrust of the first movable coil 17 and the thrust of the second movable coil 18 at the two ends of the fixed rod 16, and reduces the thrust difference between the first movable coil 17 and the second movable coil 18 in the part other than the two ends of the fixed rod 16, thereby ensuring the proper movement state of the first movable coil 17 and the second movable coil 18 relative to the fixed rod 16.

[0155] Note that although the outer magnetic yokes 19A, 19B, 19D, 19E, 19F and 19G have been described above as examples of outer magnetic yokes for reducing the magnetic flux density and the magnetic attraction force through the working hole 40, etc., the magnetic flux density can be adjusted by adjusting the size of the working hole 40, etc., thereby adjusting the thrust generated in the first movable coil 17 and the second movable coil 18.

[0156] In addition, by adjusting the magnetic flux density, the change in thrust that depends on the moving position of the movable body can be suppressed, and the unevenness of the thrust can be reduced, which stabilizes and speeds up the speed during focusing and zooming, and can improve the accuracy of the stop position of the movable body.

[0157] Note that the size and formation position of the working hole 40, working cut 41, etc. in the above-mentioned variant examples can be set arbitrarily. For example, it is possible to adopt a configuration in which the working hole 40, working cut 41, etc. are formed only at positions corresponding to the two end side parts of the fixing rod 16, and the working hole, working cut 41, etc. are not formed in parts other than the two end side parts of the fixing rod 16.

[0158] In the above description, as an example, the fixing rod 16 is covered by the outer yoke from two or three sides of the outer peripheral side. However, the fixing rod 16 may be covered by the outer yoke only from one side of the outer peripheral side. In addition, the shapes of the facing portion and the coupling portion are not limited to the flat plate shape, and may be, for example, a curved surface protruding to the side opposite to the fixing rod 16.

[0159] <Performance of Linear Actuator>

[0160] Next, the performance of the linear actuator 15 will be described (see Fig. 20and 21 ).

[0161] In order to confirm the performance of the linear actuator 15, a measurement test was conducted to measure the magnitude of the magnetic attraction force and the thrust generated in the movable coil relative to each position on the fixed rod for a conventional linear actuator without a working hole and a linear actuator with a working hole formed according to the prior art.

[0162] exist Fig. 20 In the graph, the horizontal axis represents the “position on the fixed rod” and the vertical axis represents the “attraction force of the outer yoke relative to the fixed rod.” Since the magnetic attraction force increases at a position with high magnetic flux density, the magnetic attraction force increases at a position where the inner yoke exists.

[0163] exist Fig. 20 , it can be seen that the position where each peak of the magnetic attraction force appears is the position where the inner yoke exists, and the linear actuator in which the working hole is formed has a smaller peak value than the linear actuator in which the working hole is not formed.

[0164] Therefore, it was confirmed that the magnetic attraction force of the outer yoke with respect to the fixing rod was reduced by forming the working hole.

[0165] exist Fig.21 In the graph, the horizontal axis represents the "position of the movable coil on the fixed rod" and the vertical axis represents the "thrust constant of the coil". Since the thrust generated in the movable coil is obtained by multiplying the thrust constant and the current value flowing through the movable coil, it can be considered that the thrust generated in the movable coil is larger at a position where the thrust constant value is larger. Since the thrust constant increases at a position where the magnetic flux density is high, the thrust constant increases at a position where the inner yoke exists. In addition, since the magnetic flux density at both ends of the fixed rod is larger than the magnetic flux density at the center, the thrust constant is also larger near the two ends.

[0166] exist Fig.21 , it can be seen that the difference D1 between the maximum and minimum values ​​of the thrust constant in the linear actuator in which the working hole is formed is smaller than the difference D2 between the maximum and minimum values ​​of the thrust constant in the linear actuator in which the working hole is not formed.

[0167] Therefore, it was confirmed that by forming the working hole, the difference in thrust depending on the position of the movable coil on the fixed rod was reduced.

[0168] <Overview>

[0169] As described above, in the linear actuator 15, the interchangeable lens 1 including the linear actuator 15, and the imaging device 100 including the linear actuator 15, a plurality of tubular movable coils (17 and 18) are provided in which the fixed rod 16 is inserted and which can be moved relative to the fixed rod 16 in the coupling direction of the magnet 20 and the inner magnetic yoke 21, and the plurality of movable coils can be moved individually relative to the fixed rod 16.

[0170] Therefore, each of the multiple movable coils inserted into the fixed rod 16 is energized, so that each movable coil moves individually relative to the fixed rod 16. Therefore, the fixed rod 16 is not necessary for each movable coil, and the number of components for holding the two ends of the fixed rod 16 is reduced, which reduces the layout space of the unit and enables miniaturization.

[0171] Furthermore, since the fixing rod 16 is not necessary for each movable coil and the number of components for holding both ends of the fixing rod 16 is reduced, the manufacturing cost and the number of parts can be reduced.

[0172] In addition, the length of the fixing rod 16 can be arbitrarily extended to adjust the moving stroke of each movable coil or to increase the number of movable coils, thereby significantly improving the degree of freedom in design.

[0173] <One Embodiment of Imaging Apparatus>

[0174] Hereinafter, a configuration example of an embodiment of an imaging device according to the present technology will be described (see Fig.21 ).

[0175] The imaging device 100 includes a camera module 90 attached thereto and having an imaging function, and includes a camera signal processing unit 91 that performs signal processing such as analog-to-digital conversion of a captured image signal, and an image processing unit 92 that performs recording / reproducing processing of the image signal. In addition, the imaging device 100 includes a display unit 93 that displays a captured image, etc., a reader / writer (R / W) 94 that writes and reads image signals to and from a memory 99, a central processing unit (CPU) 95 that controls the entire imaging device 100, a lens drive control unit 96 that controls the drive of a lens provided in the camera module 90, and an operation unit 97 (102) such as various switches on which a predetermined operation is performed by a user.

[0176] For example, the camera module 90 is an interchangeable lens 1 .

[0177] The imaging device 100 is provided with an imaging element 98 ( 104 ) such as a CCD or a CMOS that converts an optical image captured by the camera module 90 into an electric signal.

[0178] The camera signal processing unit 91 performs various types of signal processing such as conversion of an output signal from the imaging element 98 into a digital signal, noise removal, image quality correction, and conversion into brightness / color difference signals.

[0179] The image processing unit 92 performs compression encoding / decompression decoding processing of an image signal, conversion processing of data specifications such as resolution, and the like based on a predetermined image data format.

[0180] The display unit 93 has a function of displaying various types of data such as the user's operation status of the operation unit 97 and a captured image. Note that the imaging device 100 may not include the display unit 93, and may be configured so that the captured image data is sent to another display device and the image is displayed.

[0181] The R / W 94 writes the image data encoded by the image processing unit 92 into the memory 99 , and reads the image data recorded in the memory 99 .

[0182] The CPU 95 functions as a control processing unit that controls each circuit block provided in the imaging apparatus 100 , and controls each circuit block based on an instruction input signal or the like from the operation unit 97 .

[0183] The lens driving control unit 96 controls a driving source for moving the lens based on a control signal from the CPU 95 .

[0184] The operation unit 97 outputs an instruction input signal corresponding to a user operation to the CPU 95 .

[0185] The memory 99 is, for example, a semiconductor memory that is attachable to and detachable from a slot connected to the R / W 94 , or a semiconductor memory that is incorporated in the imaging device 100 in advance.

[0186] The operation in the imaging device 100 is described below.

[0187] In the standby state for imaging, the captured image signal is output to the display unit 93 via the camera signal processing unit 91 and displayed as a camera through image under the control of the CPU 95. In addition, when an instruction input signal is input from the operation unit 97, the CPU 95 outputs a control signal to the lens drive control unit 96, and moves the lens based on the control of the lens drive control unit 96.

[0188] When an imaging operation is performed by a command input signal from the operation unit 97, a captured image signal is output from the camera signal processing unit 91 to the image processing unit 92, subjected to compression encoding processing, and converted into digital data in a predetermined data format. The converted data is output to the R / W 94 and written to the memory 99.

[0189] In the case of reproducing image data recorded in the memory 99, in response to an operation on the operation unit 97, the R / W 94 reads predetermined image data from the memory 99, and the image processing unit 92 performs decompression decoding processing thereon, and then the reproduced image signal is output to the display unit 93, and the reproduced image is displayed.

[0190] Note that in the present technology, the term "imaging" refers to a process that includes only a part or all of a series of processes, starting from the photoelectric conversion process of converting the captured light into an electrical signal by the imaging element 98, to the process of writing the image signal in the memory 99 by the R / W94, such as the process of converting the output signal from the imaging element 98 into a digital signal, noise removal, image quality correction, and conversion into brightness / color difference signals performed by the camera signal processing unit 91, the compression encoding / decompression decoding processing of the image signal based on a predetermined image data format, and the conversion processing of data specifications such as resolution performed by the image processing unit 92.

[0191] That is, the term "imaging" may refer only to the photoelectric conversion processing of converting the captured light into an electric signal by the imaging element 98, may refer to the processing from the photoelectric conversion processing of converting the captured light into an electric signal by the imaging element 98 to the processing such as converting the output signal from the imaging element 98 into a digital signal, removing noise, correcting the image quality, and converting it into a brightness / color difference signal by the camera signal processing unit 91, and may refer to the photoelectric conversion processing from converting the captured light into an electric signal by the imaging element 98, to the processing such as converting the output signal from the imaging element 98 into a digital signal, removing noise, correcting the image quality, and converting it into a brightness / color difference signal by the camera signal processing unit 91. The processing of the image signal to the compression encoding / decompression decoding processing of the image signal based on a predetermined image data format and the conversion processing of the data specifications such as the resolution by the image processing unit 92 may refer to the photoelectric conversion processing from converting the captured light by the imaging element 98 into an electrical signal, such as the processing of converting the output signal from the imaging element 98 into a digital signal, noise removal, image quality correction and conversion into a brightness / color difference signal by the camera signal processing unit 91, and the compression encoding / decompression decoding processing of the image signal based on a predetermined image data format and the conversion processing of the data specifications such as the resolution by the image processing unit 92, and may refer to the processing until the image signal in the memory 99 is written by the R / W 94.

[0192] <This technology>

[0193] The present technology can have the following configurations.

[0194] (1) A linear actuator comprising:

[0195] a fixing rod including at least two magnets and at least one inner yoke, the magnets and the inner yoke being alternately coupled, and the magnets having magnetic poles of the same polarity coupled to both sides of the inner yoke; and

[0196] a plurality of tubular movable coils through which the fixing rod is inserted, the plurality of movable coils being movable relative to the fixing rod in a coupling direction of the magnet and the inner yoke, wherein

[0197] The plurality of movable coils are individually movable relative to the fixed rod.

[0198] (2) The linear actuator according to (1), wherein

[0199] an outer yoke covering the fixed rod and a part of the movable coil from the outer peripheral side is provided in a fixed state, and

[0200] The outer yoke includes a pair of facing portions located on opposite sides across the fixing rod.

[0201] (3) The linear actuator according to (2), wherein

[0202] At least one working hole or working cutout is formed in the facing portion, the working hole or working cutout reducing a magnetic flux density generated in the outer yoke by the fixing rod.

[0203] (4) The linear actuator according to (3), wherein

[0204] The at least one working hole or working notch is formed at a position corresponding to the inner yoke.

[0205] (5) The linear actuator according to (3) or (4), wherein

[0206] The inner yokes located at both ends in the coupling direction of the at least one inner yoke are defined as end-side inner yokes,

[0207] A working hole formed at a position corresponding to the end-side inner yoke among the at least one working hole is defined as a first working hole, and at least one working hole formed at a position corresponding to the inner yoke other than the end-side inner yoke among the at least one working hole is defined as a second working hole, and

[0208] The size of the first working hole is greater than that of the second working hole.

[0209] (6) The linear actuator according to (1), wherein

[0210] an outer yoke covering at least a portion of the fixed rod and the movable coil from an outer peripheral side is provided in a fixed state, and

[0211] At least one working hole is formed in the outer yoke, the working hole reducing a magnetic flux density generated in the outer yoke by the fixing rod.

[0212] (7) The linear actuator according to (6), wherein

[0213] The at least one working hole is formed at a position corresponding to the inner yoke.

[0214] (8) The linear actuator according to (7), wherein

[0215] The inner yokes located at both ends in the coupling direction of the at least one inner yoke are defined as end-side inner yokes,

[0216] A working hole formed at a position corresponding to the end-side inner yoke among the at least one working hole is defined as a first working hole, and at least one working hole formed at a position corresponding to the inner yoke other than the end-side inner yoke among the at least one working hole is defined as a second working hole, and

[0217] The size of the first working hole is greater than that of the second working hole.

[0218] (9) The linear actuator according to (6), wherein

[0219] The thickness of the outer yoke varies in the coupling direction.

[0220] (10) An interchangeable lens comprising:

[0221] a movable body capable of moving in the direction of the optical axis; and a linear actuator that moves the movable body in the direction of the optical axis,

[0222] Linear actuators include:

[0223] a fixing rod including at least two magnets and at least one inner yoke, the magnets and the inner yoke being alternately coupled, and the magnets having magnetic poles of the same polarity coupled to both sides of the inner yoke; and

[0224] a plurality of tubular movable coils through which the fixing rod is inserted, the plurality of movable coils being movable relative to the fixing rod in a coupling direction of the magnet and the inner yoke, wherein

[0225] The plurality of movable coils are individually movable relative to the fixed rod.

[0226] (11) An imaging device comprising:

[0227] an imaging element that converts an optical image into an electrical signal; a movable body that can move in the direction of the optical axis; and a linear actuator that moves the movable body in the direction of the optical axis,

[0228] Linear actuators include:

[0229] a fixing rod including at least two magnets and at least one inner yoke, the magnets and the inner yoke being alternately coupled, and the magnets having magnetic poles of the same polarity coupled to both sides of the inner yoke; and

[0230] a plurality of tubular movable coils through which the fixing rod is inserted, the plurality of movable coils being movable relative to the fixing rod in a coupling direction of the magnet and the inner yoke, wherein

[0231] The plurality of movable coils are individually movable relative to the fixed rod.

[0232] Reference numerals list

[0233] 100 imaging devices

[0234] 104 Imaging element

[0235] 1Interchangeable lens

[0236] 15 Linear Actuators

[0237] 16Fixed rod

[0238] 17First movable coil

[0239] 18 Second movable coil

[0240] 19 Outer yoke

[0241] 20 Magnets

[0242] 21 Inner yoke

[0243] 30 Face Section

[0244] 19A outer yoke

[0245] 30A facing part

[0246] 40 action holes

[0247] 21X end inner yoke

[0248] 40X first working hole

[0249] 40Y second working hole

[0250] 19B outer yoke

[0251] 30B facing part

[0252] 41 working cuts

[0253] 19C outer yoke

[0254] 42 coupling portion

[0255] 19D outer yoke

[0256] 42D coupling portion

[0257] 19E outer yoke

[0258] 42E coupling part

[0259] 19F outer yoke

[0260] 42F coupling part

[0261] 44 action holes

[0262] 19G outer yoke

[0263] 42G coupling

[0264] 98 Imaging Element

Claims

1. A linear actuator, comprising: a fixing rod including at least two magnets and at least one inner yoke, the magnets and the inner yoke being alternately coupled, and the magnets having magnetic poles of the same polarity coupled to both sides of the inner yoke; as well as a plurality of tubular movable coils through which the fixing rod is inserted, the plurality of movable coils being movable relative to the fixing rod in a coupling direction of the magnet and the inner yoke, wherein The plurality of movable coils are individually movable relative to the fixed rod.

2. The linear actuator according to claim 1, wherein an outer yoke covering the fixed rod and a part of the movable coil from the outer peripheral side is provided in a fixed state, and The outer yoke includes a pair of facing portions located on opposite sides across the fixing rod.

3. The linear actuator according to claim 2, wherein At least one working hole or working cutout is formed in the facing portion, the working hole or working cutout reducing a magnetic flux density generated in the outer yoke by the fixing rod.

4. The linear actuator according to claim 3, wherein The at least one working hole or working notch is formed at a position corresponding to the inner yoke.

5. The linear actuator according to claim 3 or 4, wherein: The inner yokes located at both ends in the coupling direction of the at least one inner yoke are defined as end-side inner yokes, A working hole formed at a position corresponding to the end-side inner yoke among the at least one working hole is defined as a first working hole, and at least one working hole formed at a position corresponding to the inner yoke other than the end-side inner yoke among the at least one working hole is defined as a second working hole, and The size of the first working hole is greater than that of the second working hole.

6. The linear actuator according to claim 1, wherein an outer yoke covering at least a portion of the fixed rod and the movable coil from an outer peripheral side is provided in a fixed state, and At least one working hole is formed in the outer yoke, the working hole reducing a magnetic flux density generated in the outer yoke by the fixing rod.

7. The linear actuator according to claim 6, wherein The working hole is formed at a position corresponding to the inner yoke.

8. The linear actuator according to claim 7, wherein The inner yokes located at both ends in the coupling direction of the at least one inner yoke are defined as end-side inner yokes, A working hole formed at a position corresponding to the end-side inner yoke among the at least one working hole is defined as a first working hole, and at least one working hole formed at a position corresponding to the inner yoke other than the end-side inner yoke among the at least one working hole is defined as a second working hole, and The size of the first working hole is greater than that of the second working hole.

9. The linear actuator according to claim 6, wherein The thickness of the outer yoke varies in the coupling direction.

10. An interchangeable lens comprising: A movable body capable of moving in the direction of the optical axis; and a linear actuator that moves the movable body in the direction of the optical axis, Linear actuators include: a fixing rod including at least two magnets and at least one inner yoke, the magnets and the inner yoke being alternately coupled, and the magnets having magnetic poles of the same polarity coupled to both sides of the inner yoke; as well as a plurality of tubular movable coils through which the fixing rod is inserted, the plurality of movable coils being movable relative to the fixing rod in a coupling direction of the magnet and the inner yoke, wherein The plurality of movable coils are individually movable relative to the fixed rod.

11. An imaging device comprising: An imaging element converts an optical image into an electrical signal; A movable body capable of moving in the direction of the optical axis; and a linear actuator that moves the movable body in the direction of the optical axis, Linear actuators include: a fixing rod including at least two magnets and at least one inner yoke, the magnets and the inner yoke being alternately coupled, and the magnets having magnetic poles of the same polarity coupled to both sides of the inner yoke; as well as a plurality of tubular movable coils through which the fixing rod is inserted, the plurality of movable coils being movable relative to the fixing rod in a coupling direction of the magnet and the inner yoke, wherein The plurality of movable coils are individually movable relative to the fixed rod.

Images