Lens device and imaging device

Abstract

Provided are a lens device and an imaging device by which a movable frame is moved in an optical axis direction by a linear motor. The present invention is provided with a fixed frame (12) having a fixed part (70) and a fixed part (72), a movable frame (30) having a lens (32) and coils (34, 36), a guide bar (50) having one end thereof fixed to the fixed part (70) and passing through the inside of the coil (34), and a guide bar (60) having one end thereof fixed to the fixed part (72) and passing through the inside of the coil (36). The guide bar (50) and the guide bar (60) each have a plurality of magnets (52).

Description

Lens device and imaging device

[0001] The present invention relates to a lens device and an imaging device in which a movable frame is moved in the optical axis direction by a linear motor.

[0002] Patent Document 1 discloses a drive device that uses a cylindrical magnet to move a lens holding frame in the optical axis direction. This drive device includes a cylindrical magnet that extends in a predetermined axial direction, a yoke and an excitation coil that are arranged coaxially with the cylindrical axis of the magnet, and a lens holding frame that moves integrally with the yoke and excitation coil along the predetermined axial direction when current is applied to the excitation coil.

[0003] The lens holding frame has a uniform thickness in the radial direction of the magnet and includes a sleeve portion formed between the magnet and the yoke. The sleeve portion is fitted onto the magnet so that the lens holding frame can move relative to the magnet.

[0004] JP 2013-11730 A

[0005] One embodiment of the technique of the present disclosure provides a lens device and an imaging device in which a movable frame is moved in the optical axis direction by a linear motor.

[0006] A lens device according to a first aspect of the present invention comprises a fixed frame having a first fixed portion and a second fixed portion, a first movable frame having a first lens, a first coil, and a second coil, a first axis having one end fixed to the first fixed portion and passing inside the first coil, and a second axis having one end fixed to the second fixed portion and passing inside the second coil, and the first axis and the second axis each have a plurality of magnets.

[0007] A second aspect of the present invention provides the lens device of the first aspect, wherein the first fixing portion and the second fixing portion each have an abutment portion that abuts against the magnet.

[0008] A third aspect of the present invention provides the lens device of the second aspect, wherein the outer diameter of the contact portion is smaller than the outer diameter of the magnet.

[0009] A lens device according to a fourth aspect of the present invention is based on at least one of the first to third aspects, and wherein the plurality of magnets are housed in a non-fixed manner inside the hollow cylindrical member.

[0010] In the lens device according to a fifth aspect of the present invention, in the fourth aspect, the non-fixed state is a state in which the magnet and the cylindrical member are relatively movable.

[0011] A lens device according to a sixth aspect of the present invention is, in at least one of the first to fifth aspects, a first movable frame that is arranged on both sides of a first coil and has a first insertion portion that is arranged through a first axis, and the first distance between the first axis and the first coil is larger than a second distance that is the distance between the first axis and the first insertion portion.

[0012] A seventh aspect of the present invention is a lens device according to the sixth aspect, which comprises a second movable frame having a second lens, a third coil, and a fourth coil, the second movable frame having second insertion portions arranged on both sides of the third coil, the fourth coil being arranged through the first axis, and the third coil and the second insertion portions being each arranged through the second axis.

[0013] An eighth aspect of the present invention provides the lens device of the seventh aspect, wherein a third distance between the second axis and the third coil is greater than a fourth distance between the second axis and the second insertion portion.

[0014] A ninth aspect of the present invention is a lens device according to at least one of the first to eighth aspects, wherein the fixing frame has grooves for exposing portions of the first coil and the second coil from the fixing frame.

[0015] A lens device according to a tenth aspect of the present invention is at least one of the first to ninth aspects, wherein the plurality of magnets are arranged such that adjacent magnets have the same poles facing each other.

[0016] An imaging device according to an eleventh aspect of the present invention includes the lens device according to the first aspect of the present invention.

[0017] FIG. 1 is a perspective view of a lens device according to a first embodiment. FIG. 2 is a cross-sectional view of the lens device taken along line II-II in FIG. 1. FIG. 3 is an enlarged view of the vicinity of the insertion portion shown in FIG. 2, including the insertion portion. FIG. 4 is a perspective view of a fixed frame. FIG. 5 is a perspective view of a ring-shaped cover. FIG. 6 is a cross-sectional view showing the structure for fixing a guide bar to a fixed portion. FIG. 7 is a perspective view of the vicinity of one end of a guide bar. FIG. 8 is a perspective view of a lens device according to a second embodiment. FIG. 9 is a perspective view of a lens device according to a third embodiment. FIG. 10 is a top view of the movable frame shown in FIG. 9, viewed from the optical axis direction. FIG. 11 is a front view of a camera having the lens device according to the first embodiment.

[0018] First, an overview of the present invention will be described. The lens device of the present invention is a device that moves a movable frame having a lens and the like in the optical axis direction using a drive device having a coil and a magnet. When this lens device is mounted on an imaging device such as a camera, focus adjustment and zoom adjustment are performed by moving the movable frame. The movable frame is also called a lens holding frame.

[0019] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0020] [First Embodiment] Fig. 1 is a perspective view of a lens device 10 according to a first embodiment. In Fig. 1, a fixed frame 12, which is a housing of the lens device 10, is shown in perspective in order to show the internal structure of the lens device 10. Fig. 2 is a cross-sectional view of the lens device 10 taken along line II-II in Fig. 1. As shown in Figs. 1 and 2, the lens device 10 has an optical axis P.

[0021] 1 and 2 , the lens device 10 includes a movable frame 30 having a lens 32, and a movable frame 40 having a lens 42. The lens 32 and the movable frame 30 are examples of the first lens and the first movable frame of the present invention, respectively, and the lens 42 and the movable frame 40 are examples of the second lens and the second movable frame of the present invention, respectively. Note that, although the present embodiment illustrates a lens device 10 including two movable frames 30, 40, the present invention is also applicable to a lens device including only one movable frame.

[0022] The movable frame 30 has hollow cylindrical coils 34 and 36. These coils 34, 36 are arranged on the outer periphery of the movable frame 30. When the coils 34, 36 are viewed from the direction of the optical axis P, the central axes of the coils 34, 36 are arranged in point symmetry with respect to the optical axis (optical axis P) of the lens 32. The coils 34 and 36 are examples of the first coil and the second coil, respectively, of the present invention.

[0023] The movable frame 40 has hollow cylindrical coils 44 and 46. These coils 44, 46 are arranged on the outer periphery of the movable frame 40. When the coils 44, 46 are viewed from the direction of the optical axis P, the central axes of the coils 44, 46 are arranged in point symmetry with respect to the optical axis (optical axis P) of the lens 42. The coils 44 and 46 are examples of the third coil and fourth coil, respectively, of the present invention.

[0024] The above-mentioned point-symmetric positions include positions where there is some positional deviation due to assembly errors during manufacturing or individual differences between components.

[0025] Although the coil arrangement position is not limited to the above-mentioned arrangement position, the above-mentioned arrangement position is preferable from the viewpoint of stable movement of the movable frame in the optical axis direction. In the following description, the optical axes of the lenses 32 and 42 will be collectively referred to as optical axis P.

[0026] The coils 34, 46 are arranged through a guide bar 50 that guides the movable frames 30, 40 movably in the direction of the optical axis P. The coils 36, 44 are arranged through a guide bar 60 that guides the movable frames 30, 40 movably in the direction of the optical axis P.

[0027] That is, the lens device 10 includes a guide bar 50 that passes inside the coils 34, 46, and a guide bar 60 that passes inside the coils 36, 44. The axes of these guide bars 50, 60 are arranged parallel to the optical axis P, and one end of each is fixed to a fixing frame 12, which will be described later. The guide bar 50 and the guide bar 60 are examples of the first axis and the second axis, respectively, of the present invention.

[0028] The above-mentioned "parallel" also includes cases where there is a slight tilt due to assembly errors during manufacturing or individual differences between components.

[0029] The movable frame 30 has insertion portions 38. The insertion portions 38 are arranged on both sides of the coil 34, and are arranged with guide bars 50 passing through them. The movable frame 40 has insertion portions 48. The insertion portions 48 are arranged on both sides of the coil 44, and are arranged with guide bars 60 passing through them. The insertion portions 38 and 48 are examples of the first insertion portion and the second insertion portion, respectively, of the present invention.

[0030] Fig. 3 is an enlarged view of the vicinity of the insertion portion 38 shown in Fig. 2. As shown in Fig. 3, the insertion portion 38 has a pair of ring portions 38A, 38A arranged on both sides of the coil 34 in the direction of the optical axis P.

[0031] The guide bar 50 is passed through the openings of the ring portions 38A, 38A with a gap therebetween. That is, the guide bar 50 and the insertion portion 38 are arranged with a gap therebetween. Similarly, the guide bar 50 and the coil 34 are also arranged with a gap therebetween.

[0032] The first distance A, which is the distance between the guide bar 50 and the coil 34, is set larger than the second distance B, which is the distance between the guide bar 50 and the insertion portion 38. Specifically, the first distance A, which is the distance between the outer peripheral surface of the guide bar 50 and the inner peripheral surface of the coil 34, is set larger than the second distance B, which is the distance between the outer peripheral surface of the guide bar 50 and the inner peripheral surface of the opening of the ring portion 38A.

[0033] The above-mentioned intervals refer to intervals (gaps) in a direction perpendicular to the optical axis P (diameter direction of the guide bar 50). For example, in the radial direction of the guide bar 50, the first interval A is set to several hundred microns (μm), and the second interval B is set to several microns.

[0034] By making the second distance B smaller than the first distance A, the insertion portion 38 functions as a sliding portion of the movable frame 30 relative to the guide bar 50, and also has the function of preventing the coil 34 from contacting the guide bar 50 while the movable frame 30 is moving.

[0035] Although the description of the insertion portion 48 shown in FIG. 2 will be omitted in the same manner as the insertion portion 38, the configuration of the insertion portion 48 is the same as the configuration of the insertion portion 38.

[0036] That is, the insertion portion 48 has a pair of ring portions 48A, 48A arranged on both sides of the coil 44 in the direction of the optical axis P. The guide bar 60 is passed through the openings of each of these ring portions 48A, 48A at a distance from each other. That is, the guide bar 60 and the insertion portion 48 are arranged at a distance from each other. Similarly, the guide bar 60 and the coil 44 are also arranged at a distance from each other.

[0037] The third distance, which is the distance between the guide bar 60 and the coil 44, is set to be larger than the fourth distance, which is the distance between the guide bar 60 and the insertion portion 48. Specifically, the third distance, which is the distance between the outer peripheral surface of the guide bar 60 and the inner peripheral surface of the coil 44, is set to be larger than the fourth distance, which is the distance between the outer peripheral surface of the guide bar 60 and the inner peripheral surface of the opening of the ring portion 48A.

[0038] For example, the third interval is set to several hundred microns in the radial direction of the guide bar 60, and the fourth interval is set to several microns.

[0039] By making the fourth gap smaller than the third gap, the insertion portion 48 functions as a sliding portion for the movable frame 40 relative to the guide bar 60, and also has the function of preventing the coil 44 from contacting the guide bar 60 during movement of the movable frame 40. Note that the third gap and the fourth gap are preferably equal to the first gap A and the second gap B, respectively.

[0040] As described above, the lens device 10 of this embodiment has a configuration in which the guide bar 50 passes through the insertion portion 38 of the movable frame 30, and the guide bar 60 passes through the insertion portion 48 of the movable frame 40. With this configuration, the movable frame 30 moves with the guide bar 50 as its main axis and the guide bar 60 as its secondary axis. Also, the movable frame 40 moves with the guide bar 60 as its main axis and the guide bar 50 as its secondary axis. Then, as shown in FIGS. 2 and 3 , by arranging the insertion portions 38 (and similarly the insertion portions 48) on both sides of the coil 34, it is possible to make the distance D between the ring portions 38A larger than the length C of the coil 34 in the direction of the optical axis P (C<D).

[0041] With this configuration, the lens device 10 of this embodiment can ensure the movable stroke of the movable frames 30, 40 while suppressing the tilt of the lenses 32, 42 with respect to the optical axis P.

[0042] Next, a description will be given of the guide bar 50. As the guide bar 60 has the same configuration as the guide bar 50, it is given the same reference numeral as the guide bar 50 and a description thereof will be omitted.

[0043] 2 and 3, the guide bar 50 has a plurality of permanent magnets 52. In the following description, the permanent magnets will be abbreviated as magnets.

[0044] The plurality of magnets 52 are each configured in a solid cylindrical shape and are housed inside (in the hollow portion of) the hollow shaft case 54. That is, the plurality of magnets 52 are housed along the axial direction of the shaft case 54.

[0045] In this case, the distance between the outer peripheral surface of the shaft case 54 and the inner peripheral surface of the coil 34 corresponds to the first distance A, and the distance between the outer peripheral surface of the shaft case 54 and the inner peripheral surface of the opening of the ring portion 38A corresponds to the second distance B. The shaft case 54 is an example of a hollow tubular member of the present invention.

[0046] Adjacent magnets 52 are arranged with the same poles facing each other in the axial direction of the shaft case 54. The multiple magnets 52 are housed loosely relative to each other inside the shaft case 54. Being loosely housed means that the magnets 52 and the shaft case 54 are movable relative to each other. As a result, the multiple magnets 52 are housed loosely relative to each other inside the shaft case 54 in the axial direction of the shaft case 54.

[0047] In this case, the magnets 52 may be arranged in close contact with adjacent magnets 52, or may be arranged with spaces between them. If multiple magnets 52 are arranged with spaces between them, the number of magnets 52 housed in the shaft case 54 can be reduced, thereby reducing manufacturing costs and weight. When arranging magnets with spaces between them, spacers can be used.

[0048] A rare earth magnet is exemplified as a material for the magnet 52. An aluminum alloy, a copper alloy, a non-magnetic stainless steel, or other non-magnetic material is exemplified as a material for the shaft case 54. The shaft case 54 is configured to be thin (for example, 1 mm or less) so as not to reduce the magnetic field acting on the coils 34, 46 arranged outside it.

[0049] With this configuration, the lens device 10 of this embodiment includes a shaft-type voice coil motor having the guide bar 50 and the coils 34 and 46, and a shaft-type voice coil motor having the guide bar 60 and the coils 36 and 44. In other words, the lens device 10 includes two voice coil motors.

[0050] Therefore, according to the lens device 10 of this embodiment, when current is applied to the coils 34, 36, a driving force (thrust) is generated in the coils 34, 36 in the axial direction of the guide bars 50, 60, and the movable frame 30, together with the coils 34, 36, moves parallel to the direction of the optical axis P, guided by the guide bars 50, 60. Furthermore, when current is applied to the coils 44, 46, a driving force (thrust) is generated in the coils 44, 46 in the axial direction of the guide bars 60, 50, and the movable frame 40, together with the coils 44, 46, moves parallel to the direction of the optical axis P, guided by the guide bars 50, 60. Focus adjustment and zoom adjustment are performed by such movement of the movable frames 30, 40.

[0051] <Comparative Example> Here, a comparison is made with a lens device (such as the lens device of Patent Document 1) configured to move a movable frame in the optical axis direction by one guide bar (voice coil motor (main shaft)) and one guide bar (non-voice coil motor (sub-shaft)). In the lens device of the comparative example, the movable frame is moved by one voice coil motor, so there are cases where the movable frame (lens) moves in a state tilted with respect to the optical axis.

[0052] In contrast, the lens device 10 of this embodiment is configured to move the movable frames in the optical axis direction using two voice coil motors, so the movable frames 30, 40 (lenses 32, 42) can be moved with a large thrust without tilting with respect to the optical axis P. Furthermore, the two coils provided on the movable frames are positioned point-symmetrically about the optical axis P, so the movable frames 30, 40 can be moved stably.

[0053] Furthermore, the lens device 10 of this embodiment is configured so that the guide bar 60, which is the secondary shaft of the movable frame 30, is used as the primary shaft of the movable frame 40, and the guide bar 50, which is the secondary shaft of the movable frame 40, is used as the primary shaft of the movable frame 30, so that the number of parts (the number of guide bars) can be reduced compared to a lens device in which each movable frame has a primary shaft and a secondary shaft, making it possible to provide a small and lightweight lens device 10.

[0054] In addition, the lens device 10 of this embodiment is exemplified as a guide bar 50 having a plurality of magnets 52 and a shaft case 54, but the guide bar 50 may also be constructed by gluing adjacent magnets 52 together or gluing them together via a spacer without using a shaft case 54.

[0055] Next, the fixing structure of the guide bars 50, 60 will be described.

[0056] 2, fixed frame 12 has a fixing portion 70 for fixing one end (the lower end in FIG. 1) of guide bar 50, and a fixing portion 72 for fixing one end (the lower end in FIG. 1) of guide bar 60. Fixed portion 70 and fixed portion 72 are examples of the first and second fixing portions of the present invention, respectively.

[0057] For the sake of convenience, the above-mentioned ends of the guide bars 50, 60 will be referred to as the lower ends, and the ends opposite to the above-mentioned ends will be referred to as the upper ends.

[0058] 1 and 2, the fixed frame 12 has a substantially cylindrical frame body 14 that covers the outer peripheries of the two movable frames 30, 40, and a ring-shaped bottom body 16 that is provided with fixing portions 70, 72. The bottom body 16 is configured integrally with the frame body 14 at the lower end thereof. Note that the bottom body 16 may be configured as a separate body from the frame body 14, and may be fixed to the lower end of the frame body 14 when the lens device 10 is assembled.

[0059] Fig. 4 is a perspective view of the fixed frame 12. As shown in Fig. 4, the frame body 14 of the fixed frame 12 has two slits 18, 20 extending along the direction of the optical axis P. These slits 18, 20 are provided at positions point-symmetric with respect to the optical axis P when the frame body 14 is viewed from the direction of the optical axis P.

[0060] Coils 34, 46 are arranged in the slit 18, and coils 36, 44 are arranged in the slit 20. As a result, when the movable frames 30, 40 move, the coils 34, 46 move along the slit 18, and the coils 36, 44 move along the slit 20.

[0061] That is, the slit 18 is provided as a groove for exposing a portion of the coils 34, 46 from the frame 14, and the slit 20 is provided as a groove for exposing a portion of the coils 36, 44 from the frame 14. The slits 18, 20 are each an example of a groove in the present invention. By providing such slits 18, 20 in the frame 14, the diameter of the frame 14 can be reduced. This makes it possible to provide a small and lightweight lens device 10.

[0062] 5 is a perspective view of the ring-shaped cover 22. The cover 22 is formed separately from the fixed frame 12, and is fixed to the upper end of the fixed frame 12 when the lens device 10 is assembled.

[0063] The cover 22 has a fixing portion 80 for fixing the upper end of the guide bar 50 and a fixing portion 82 for fixing the upper end of the guide bar 60 .

[0064] Returning to Figure 2, guide bar 50 is fixed to bottom body 16 and lid body 22 with both ends sandwiched between fixing portions 70 and 80, and guide bar 60 is fixed to bottom body 16 and lid body 22 with both ends sandwiched between fixing portions 72 and 82.

[0065] Figure 6 is a cross-sectional view showing the detailed fixing structure of guide bar 50 relative to fixing portions 70, 80. Fig. 6 shows only the vicinity of both ends of guide bar 50, omitting other portions. Fig. 7 is an enlarged perspective view of the vicinity of guide bar 50, including the lower end. Note that the fixing structure of guide bar 60 relative to fixing portions 72, 82 is the same as the fixing structure of guide bar 50, and therefore the same reference numerals are used and a description thereof will be omitted.

[0066] 6 and 7, the multiple magnets 52 housed in the shaft case 54 are arranged such that the bottom surface 52A of the magnet 52 located at the bottom of the drawing is located above the bottom end 54A of the shaft case 54. Also, as shown in Fig. 6, the multiple magnets 52 are arranged such that the top surface 52B of the magnet 52 located at the top of the multiple magnets 52 is located below the top end 54B of the shaft case 54.

[0067] 4 and 6, the fixing portion 70 has a ring-shaped recess 74 formed on the surface 16A of the bottom body 16 and a cylindrical (or disk-shaped) protrusion 76 surrounded by the recess 74. The outer diameter (diameter) D1 of the protrusion 76 is smaller than the outer diameter (diameter) D2 of the magnet 52. The surface 76A of the protrusion 76 is disposed at a recessed position relative to the surface 16A of the bottom body 16. The diameter of the recess 74 is larger than the diameter of the shaft case 54.

[0068] 5 and 6, the fixing portion 80 has a ring-shaped recess 84 formed in the surface 22A of the lid 22, and a cylindrical (or disk-shaped) protrusion 86 surrounded by the recess 84. The outer diameter D3 of the protrusion 86 (e.g., D3 = D1) is configured to be smaller than the outer diameter D2 of the magnet 52. The surface 86A of the protrusion 86 is disposed in a recessed position relative to the surface 22A of the lid 22. The diameter of the recess 84 is larger than the diameter of the shaft case 54.

[0069] For the fixed portions 70 and 80 configured as described above, the guide bar 50 has the lower end 54A of the shaft case 54 fitted into the recess 74 of the fixed portion 70, and the lower surface 52A of the magnet 52 abutting against the surface 76A of the protrusion 76. Also, the upper end 54B of the shaft case 54 fits into the recess 84 of the fixed portion 80, and the upper surface 52B of the magnet 52 abutting against the surface 86A of the protrusion 86. The protrusions 76 of the fixed portions 70 and 72 are each an example of an abutment portion of the present invention.

[0070] As a result, guide bar 50 is fixed to bottom body 16 and lid body 22 by fixing portions 70 and 80. Then, the magnets 52 are sandwiched between protrusions 76 and 86, and the positions of the magnets 52 in the direction of optical axis P are determined. In this case, lower surface 52A and upper surface 52B function as positioning surfaces for positioning the magnets 52.

[0071] With this structure for fixing the guide bar 50, the lens device 10 of this embodiment can fix the guide bar 50 parallel to the optical axis P and can suppress variations in the positions of the multiple magnets 52 in the direction of the optical axis P. This ensures stability in the driving force (thrust) of the voice coil motor described above.

[0072] Second Embodiment Fig. 8 is a perspective view of a lens device 100 according to a second embodiment. Note that Fig. 8 also shows the fixed frame 12 in a see-through manner, as in Fig. 1. In describing the lens device 100 in Fig. 8, components that are the same as or similar to those in the lens device 10 according to the first embodiment shown in Figs. 1 to 7 are designated by the same reference numerals, and descriptions thereof will be omitted.

[0073] The difference in configuration between the first embodiment and the second embodiment is that the lens device 10 of the first embodiment is equipped with two guide bars 50, 60, while the lens device 100 of the second embodiment is equipped with one guide bar 110 in addition to the two guide bars 50, 60.

[0074] 8, guide bar 110 is disposed parallel to guide bars 50 and 60. This guide bar 110 has the same configuration as guide bars 50 and 60, and is fixed to bottom body 16 and lid body 22 by the same fixing structure as guide bars 50 and 60. Therefore, a description of the configuration and fixing structure of guide bar 110 will be omitted here.

[0075] The movable frame 30 has a coil 120, and the movable frame 40 has a coil 130. The coils 120 and 130 are arranged through the guide bar 110.

[0076] That is, the lens device 100 of the second embodiment has one guide bar 50 as the main shaft of the movable frame 30, and two guide bars 60, 110 as the secondary shafts of the movable frame 30. Also, the movable frame 40 has one guide bar 60 as the main shaft, and two guide bars 50, 110 as the secondary shafts of the movable frame 40. In other words, the lens device 100 has a third voice coil motor in addition to the two voice coil motors that the lens device 10 has.

[0077] According to the lens device 100 of the second embodiment, the movable frames 30, 40 are moved by three voice coil motors, and therefore the movable frames 30, 40 can be moved with a greater thrust than the lens device 10 of the first embodiment.

[0078] Furthermore, because the guide bar 110 is shared by the movable frames 30 and 40, the number of parts (the number of guide bars) can be reduced compared to a lens device in which each movable frame has a main shaft and a sub shaft, making it possible to provide a compact and lightweight lens device 100.

[0079] 8, the coil 34 (46) and the coil 36 (44: not shown) are not arranged in point-symmetric positions around the optical axis P, but the coil 36 (44: not shown) and the coil 120 (130) are arranged in point-symmetric positions around the optical axis P. However, the arrangement positions of the coils are not limited to the above positions, and for example, the coil 34 (46) and the coil 120 (130) may be interchanged, or the coil 34 (46) and the coil 36 (44: not shown) may be interchanged.

[0080] Third Embodiment Fig. 9 is a perspective view of a lens device 200 according to a third embodiment. Note that Fig. 9 also shows the fixed frame 12 in a see-through manner, as in Figs. 1 and 8. In describing the lens device 200 in Fig. 9, components that are the same as or similar to those in the lens device 100 according to the second embodiment shown in Fig. 8 are designated by the same reference numerals, and descriptions thereof will be omitted.

[0081] The difference in configuration between the second embodiment and the third embodiment is that the lens device 100 of the second embodiment has three guide bars 50, 60, and 110, while the lens device 200 of the third embodiment has one guide bar 210 in addition to the three guide bars 50, 60, and 110.

[0082] 9, guide bar 210 is disposed parallel to guide bars 50, 60, and 110. This guide bar 210 has the same configuration as guide bars 50, 60, and 110, and is fixed to bottom body 16 and lid body 22 by the same fixing structure as guide bars 50, 60, and 110. Therefore, a description of the configuration and fixing structure of guide bar 210 will be omitted here.

[0083] The movable frame 30 has a coil (not shown) through which the guide bar 210 is passed, and the movable frame 40 has a coil (not shown) through which the guide bar 210 is passed.

[0084] That is, the lens device 200 of the third embodiment has one guide bar 50 as the main shaft of the movable frame 30, and three guide bars 60, 110, 210 as the secondary shafts of the movable frame 30. Also, the movable frame 40 has one guide bar 60 as the main shaft, and three guide bars 50, 110, 210 as the secondary shafts of the movable frame 40. In other words, the lens device 200 has a fourth voice coil motor in addition to the three voice coil motors that the lens device 100 has.

[0085] According to the lens device 200 of the third embodiment, the movable frames 30, 40 are moved by four voice coil motors, and therefore the movable frames 30, 40 can be moved with a greater thrust than the lens device 100 of the second embodiment.

[0086] Fig. 10 is a top view of the movable frame 30 shown in Fig. 9 as viewed from the direction of the optical axis P. Fig. 10 shows the manner in which the movable frame 30 is attached to the four guide bars 50, 60, 110, and 210. The four guide bars 50, 60, 110, and 210 are arranged at equal intervals on the same circumference centered on the optical axis P.

[0087] 10, the movable frame 30 is attached to the guide bar 50, which is the main shaft, by passing the guide bar 50 through the opening of the ring portion 38A of the insertion portion 38. In this case, the first distance A (see FIG. 3), which is the distance between the insertion portion 38 and the guide bar 50, is set to several microns, as described above. This allows the movable frame 30 to be movably attached to the guide bar 50 with the insertion portion 38 as a sliding portion.

[0088] The movable frame 30 is attached to three guide bars 60, 110, and 210, which serve as secondary shafts, by passing the guide bars 60 and 110 through openings 30A and 30B provided on the outer periphery of the movable frame 30 and passing the guide bar 210 through a U-shaped cutout 30C provided on the outer periphery of the movable frame 30. In this case, the distances between the openings 30A and 30B and the guide bars 60 and 110 are each set to several hundred microns. This allows the guide bars 60 and 110 to support the movable frame 30 so that the entire lens device does not break when subjected to an impact or the like. Furthermore, the guide bar 210 comes into contact with the cutout 30C at two locations (two points) in the circumferential direction, thereby preventing rotation of the movable frame 30 about the optical axis P.

[0089] In this way, by setting the distance between the guide bar 50, which is the main axis of the four guide bars 50, 60, 110, and 210, and the insertion portion 38 to be smaller than the distance between the other guide bars 60 and 110, it is possible to achieve both improved straight-line accuracy of the movable frame 30 (lens 32) and improved ease of assembly of the movable frame 30 to the four guide bars 50, 60, 110, and 210.

[0090] Figure 11 is a front view of a camera 220 having the lens apparatus 10 shown in Figure 1. The camera 220 has a camera body 222, and the lens apparatus 10 is provided in front of this camera body 222. The camera 220 also has a viewfinder 224 and a release button 226.

[0091] Although Fig. 11 shows a camera 220 having the lens apparatus 10 shown in Fig. 1, the present invention is not limited to this and may also be a camera 220 having the lens apparatus 100 shown in Fig. 8 or the lens apparatus 200 shown in Fig. 9. The camera 220 is an example of an imaging device of the present invention.

[0092] Although the lens device and imaging device according to the present embodiment have been described above, the present invention may be improved or modified in several ways without departing from the spirit and scope of the present invention.

[0093] REFERENCE SIGNS LIST 10 Lens device 12 Fixed frame 14 Frame body 16 Bottom body 16A Surface 18 Slit 20 Slit 22 Cover body 22A Surface 30 Movable frame 30A Opening 30B Opening 30C Notch portion 32 Lens 34 Coil 36 Coil 38 Insertion portion 38A Ring portion 40 Movable frame 42 Lens 44 Coil 46 Coil 48 Insertion portion 48A Ring portion 50 Guide bar 52 Magnet 52A Lower surface 52B Upper surface 54 Shaft case 54A Lower end 54B Upper end 60 Guide bar 70 Fixed portion 72 Fixed portion 74 Recessed portion 76 Convex portion 76A Surface 80 Fixed portion 82 Fixed portion 84 Convex portion 86 Convex portion 86A Surface 100 Lens device 110 Guide bar 120 Coil 130 Coil 200 Lens device 210 Guide bar 220 Camera 222 Camera body 224 Finder 226 Release button

Claims

1. A lens device comprising: a fixed frame having a first fixed portion and a second fixed portion; a first movable frame having a first lens, a first coil, and a second coil; a first axis having one end fixed to the first fixed portion and passing inside the first coil; and a second axis having one end fixed to the second fixed portion and passing inside the second coil, wherein the first axis and the second axis each have a plurality of magnets.

2. The lens device according to claim 1, wherein the first fixing portion and the second fixing portion each have an abutment portion that abuts against the magnet.

3. The lens device according to claim 2, wherein the outer diameter of the contact portion is smaller than the outer diameter of the magnet.

4. The lens device according to claim 1 or 2, wherein the plurality of magnets are housed in a non-fixed state inside a hollow cylindrical member.

5. The lens device according to claim 4, wherein the non-fixed state is a state in which the magnet and the cylindrical member are relatively movable.

6. A lens device according to claim 1 or 2, wherein the first movable frame is arranged on both sides of the first coil and has a first insertion portion arranged through which the first axis passes, and a first distance between the first axis and the first coil is larger than a second distance between the first axis and the first insertion portion.

7. A lens device according to claim 6, comprising a second movable frame having a second lens, a third coil, and a fourth coil, wherein the second movable frame has second insertion portions disposed on both sides of the third coil, the fourth coil being disposed through the first axis, and the third coil and the second insertion portions being disposed through the second axis, respectively.

8. The lens device according to claim 7, wherein a third distance between the second axis and the third coil is greater than a fourth distance between the second axis and the second insertion portion.

9. The lens device according to claim 1, wherein the fixed frame has grooves for exposing portions of the first coil and the second coil from the fixed frame.

10. The lens device according to claim 1, wherein adjacent magnets of the plurality of magnets are arranged with the same poles facing each other.

11. An imaging device comprising the lens device according to claim 1.

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